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Feuerriegel GC, Sutter R. Managing hardware-related metal artifacts in MRI: current and evolving techniques. Skeletal Radiol 2024; 53:1737-1750. [PMID: 38381196 PMCID: PMC11303499 DOI: 10.1007/s00256-024-04624-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 02/22/2024]
Abstract
Magnetic resonance imaging (MRI) around metal implants has been challenging due to magnetic susceptibility differences between metal implants and adjacent tissues, resulting in image signal loss, geometric distortion, and loss of fat suppression. These artifacts can compromise the diagnostic accuracy and the evaluation of surrounding anatomical structures. As the prevalence of total joint replacements continues to increase in our aging society, there is a need for proper radiological assessment of tissues around metal implants to aid clinical decision-making in the management of post-operative complaints and complications. Various techniques for reducing metal artifacts in musculoskeletal imaging have been explored in recent years. One approach focuses on improving hardware components. High-density multi-channel radiofrequency (RF) coils, parallel imaging techniques, and gradient warping correction enable signal enhancement, image acquisition acceleration, and geometric distortion minimization. In addition, the use of susceptibility-matched implants and low-field MRI helps to reduce magnetic susceptibility differences. The second approach focuses on metal artifact reduction sequences such as view-angle tilting (VAT) and slice-encoding for metal artifact correction (SEMAC). Iterative reconstruction algorithms, deep learning approaches, and post-processing techniques are used to estimate and correct artifact-related errors in reconstructed images. This article reviews recent developments in clinically applicable metal artifact reduction techniques as well as advances in MR hardware. The review provides a better understanding of the basic principles and techniques, as well as an awareness of their limitations, allowing for a more reasoned application of these methods in clinical settings.
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Affiliation(s)
- Georg C Feuerriegel
- Department of Radiology, Balgrist University Hospital, Faculty of Medicine, University of Zurich, Forchstrasse 340, 8008, Zurich, Switzerland.
| | - Reto Sutter
- Department of Radiology, Balgrist University Hospital, Faculty of Medicine, University of Zurich, Forchstrasse 340, 8008, Zurich, Switzerland
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Kim S, Shin D, Lee C, Yu D, Cho J, Bang H, Lee H, Kim D, Park I, Hong J, Joung S. Clinical efficacy and performance evaluation of a bendable remote robot system for a bone tumour surgery: A pilot animal study. Int J Med Robot 2024; 20:e2653. [PMID: 38934235 DOI: 10.1002/rcs.2653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/14/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Abstract
BACKGROUND Traditional open surgery for bone tumours sometimes has as a consequence an excessive removal of healthy bone tissue because of the limitations of rigid surgical instruments, increasing infection risk and recovery time. METHODS We propose a remote robot with a 4.5-mm diameter bendable end-effector, offering four degrees of freedom for accessing the inside of the bone and performing tumour debridement. The preclinical studies evaluated the effectiveness, clinical scenario, and usability across 12 total surgeries-six phantom surgeries and six bovine bone surgeries. Evaluation criteria included skin incision size, bone window size, surgical time, removal rate, and conversion to open surgery. RESULTS Preclinical studies demonstrated that the robotic approach requires significantly smaller incision size and procedure times than traditional open curettage. CONCLUSION This study validated the performance of the proposed system by assessing its preclinical effectiveness and optimising surgical methods using human phantom and bovine bone tumour models.
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Affiliation(s)
- Seungmin Kim
- Department of Research, AIRS Inc., 202 Robot Innovation Center, Daegu, South Korea
| | - Donghyun Shin
- Department of Research, AIRS Inc., 202 Robot Innovation Center, Daegu, South Korea
| | - Changhyeon Lee
- Department of Research, AIRS Inc., 202 Robot Innovation Center, Daegu, South Korea
| | - Daehee Yu
- Department of Research, AIRS Inc., 202 Robot Innovation Center, Daegu, South Korea
| | - Jongho Cho
- Department of Research, AIRS Inc., 202 Robot Innovation Center, Daegu, South Korea
| | - Hyunhee Bang
- Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, South Korea
| | - Hyunjoo Lee
- Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, South Korea
| | - Donghyun Kim
- Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, South Korea
| | - Ilhyung Park
- Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, South Korea
| | - Jaesung Hong
- Department of Robotics and Mechatronics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Sanghyun Joung
- Department of Research, AIRS Inc., 202 Robot Innovation Center, Daegu, South Korea
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3
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Goller SS, Sutter R. Advanced Imaging of Total Knee Arthroplasty. Semin Musculoskelet Radiol 2024; 28:282-292. [PMID: 38768593 DOI: 10.1055/s-0044-1781470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The prevalence of total knee arthroplasty (TKA) is increasing with the aging population. Although long-term results are satisfactory, suspected postoperative complications often require imaging with the implant in place. Advancements in computed tomography (CT), such as tin prefiltration, metal artifact reduction algorithms, dual-energy CT with virtual monoenergetic imaging postprocessing, and the application of cone-beam CT and photon-counting detector CT, allow a better depiction of the tissues adjacent to the metal. For magnetic resonance imaging (MRI), high bandwidth (BW) optimization, the combination of view angle tilting and high BW, as well as multispectral imaging techniques with multiacquisition variable-resonance image combination or slice encoding metal artifact correction, have significantly improved imaging around metal implants, turning MRI into a useful clinical tool for patients with suspected TKA complications.
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Affiliation(s)
- Sophia Samira Goller
- Department of Radiology, Balgrist University Hospital, Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | - Reto Sutter
- Department of Radiology, Balgrist University Hospital, Faculty of Medicine, University of Zurich, Zurich, Switzerland
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Srivastav S, Spin-Neto R, Aiyar A, Stoustrup PB. Accuracy and reliability of magnetic resonance imaging in orthodontic diagnosis and treatment planning-a systematic review and meta-analysis. Eur J Orthod 2024; 46:cjae019. [PMID: 38700388 DOI: 10.1093/ejo/cjae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) is a non-ionizing imaging technique. Using MRI in dentistry may potentially lower the general radiation dose of the examined population, provided MRI can replace various radiation-based images. Furthermore, novel MRI imaging modalities for three-dimensional and two-dimensional cephalometrics have recently been developed for orthodontic diagnosis. OBJECTIVES This systematic review aimed to determine the diagnostic accuracy and reliability of MRI in orthodontic diagnosis and treatment planning. SEARCH METHODS An electronic search was conducted on 20 November 2022 in the following databases: PubMed, LILACS, Web of Science, EMBASE, Scopus, and Cochrane. The search was updated on 30 August 2023. Furthermore, a grey literature search was performed in Google Scholar and Open-Grey. SELECTION CRITERIA This review included descriptive, observational, cohort studies, cross-sectional, case-control studies, and randomized/non-randomized trials related to the research question. The study excluded studies related to patients with syndromes, chronic diseases, craniofacial anomalies, or bone diseases. DATA COLLECTION AND ANALYSIS The included studies were quality assessed using the "Joanna Brigg's Critical Appraisal Tool for diagnostic test accuracy". The GRADE approach for non-randomized studies was used for strength-of-evidence analysis. RESULTS Eight of the 10 included studies compared MRI with either cone beam computed tomography or lateral cephalogram and found a high intra- and inter-rater agreement for landmark identification. The risk of bias was high in four studies, moderate in three, and low in three studies. Homogeneity was lacking among the included studies in terms of MRI imaging parameters and sample characteristics. This should be taken into consideration by future studies where uniformity with respect to these parameters may be considered. CONCLUSIONS Despite dissimilarity and heterogeneity in the sample population and other methodological aspects, all the included studies concluded that MRI enjoyed considerable intra- and inter-examiner reliability and was comparable to current diagnostic standards in orthodontics. Furthermore, the studies agreed on the innovative potential of MRI in radiation-free diagnosis and treatment planning in orthodontics in the future. REGISTRATION CRD number: CRD420223XXXXX.
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Affiliation(s)
- Sukeshana Srivastav
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Vennelyst Boulevard 9, Building 1613, DK 8000 Aarhus, Denmark
| | - Rubens Spin-Neto
- Section of Oral Radiology and Endodontics, Department of Dentistry and Oral Health, Aarhus University, Vennelyst Boulevard 9, Building 1613, DK 8000 Aarhus, Denmark
| | - Akila Aiyar
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Vennelyst Boulevard 9, Building 1613, DK 8000 Aarhus, Denmark
| | - Peter Bangsgaard Stoustrup
- Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Vennelyst Boulevard 9, Building 1613, DK 8000 Aarhus, Denmark
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Hu Y, Han C, Huo X, Cao X, Chen Y, Cao Z, Xu Y, Tao L, Wu Z. Flexible Sensor for Real-Time Monitoring of Motion Artifacts in Magnetic Resonance Imaging. ACS Sens 2024; 9:2614-2621. [PMID: 38752282 DOI: 10.1021/acssensors.4c00319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
In recent years, magnetic resonance imaging has been widely used in the medical field. During the scan, if the human body moves, then there will be motion artifacts on the scan image, which will interfere with the diagnosis and only be found after the end of the scan sequence, resulting in a waste of manpower and resources. However, there is a lack of technology that halts scanning once motion artifacts arise. Here, we designed a real-time monitoring sensor (RMS) to dynamically perceive the movement of the human body and to pause in time when the movement exceeds a certain amplitude. The sensor has an array structure that can accurately sense the position of the human body in real time. The selection of the RMS ensures that there is no additional interference with the scanning results. Based on this design, the RMS can achieve the monitoring function of motion artifact generation.
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Affiliation(s)
- Yiran Hu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing101400, China
- College of Nanoscience and Technology, University of Chinese Academy of Science, Beijing100049, China
| | - Chengcheng Han
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing101400, China
- College of Nanoscience and Technology, University of Chinese Academy of Science, Beijing100049, China
| | - Xiaoqing Huo
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing101400, China
- College of Nanoscience and Technology, University of Chinese Academy of Science, Beijing100049, China
| | - Xiaole Cao
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing101400, China
- College of Nanoscience and Technology, University of Chinese Academy of Science, Beijing100049, China
| | - Yongyang Chen
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing101400, China
- Geological Brigade 105, Bureau of Geology and Mineral Exploration and Development of Guizhou Province, Guiyang550018, China
| | - Zhi Cao
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing101400, China
- College of Nanoscience and Technology, University of Chinese Academy of Science, Beijing100049, China
| | - Yong Xu
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing400016, China
| | - Li Tao
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing400016, China
| | - Zhiyi Wu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing101400, China
- College of Nanoscience and Technology, University of Chinese Academy of Science, Beijing100049, China
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Ramos-Torres KM, Conti S, Zhou YP, Tiss A, Caravagna C, Takahashi K, He M, Wilks MQ, Eckl S, Sun Y, Biundo J, Gong K, He Z, Linnman C, Brugarolas P. Imaging demyelinated axons after spinal cord injuries with PET tracer [ 18 F]3F4AP. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.590984. [PMID: 38712041 PMCID: PMC11071504 DOI: 10.1101/2024.04.24.590984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Spinal cord injuries (SCI) often lead to lifelong disability. Among the various types of injuries, incomplete and discomplete injuries, where some axons remain intact, offer potential for recovery. However, demyelination of these spared axons can worsen disability. Demyelination is a reversible phenomenon, and drugs like 4-aminopyridine (4AP), which target K+ channels in demyelinated axons, show that conduction can be restored. Yet, accurately assessing and monitoring demyelination post-SCI remains challenging due to the lack of suitable imaging methods. In this study, we introduce a novel approach utilizing the positron emission tomography (PET) tracer, [ 18 F]3F4AP, specifically targeting K+ channels in demyelinated axons for SCI imaging. Rats with incomplete contusion injuries were imaged up to one month post-injury, revealing [ 18 F]3F4AP's exceptional sensitivity to injury and its ability to detect temporal changes. Further validation through autoradiography and immunohistochemistry confirmed [ 18 F]3F4AP's targeting of demyelinated axons. In a proof-of-concept study involving human subjects, [ 18 F]3F4AP differentiated between a severe and a largely recovered incomplete injury, indicating axonal loss and demyelination, respectively. Moreover, alterations in tracer delivery were evident on dynamic PET images, suggestive of differences in spinal cord blood flow between the injuries. In conclusion, [ 18 F]3F4AP demonstrates efficacy in detecting incomplete SCI in both animal models and humans. The potential for monitoring post-SCI demyelination changes and response to therapy underscores the utility of [ 18 F]3F4AP in advancing our understanding and management of spinal cord injuries.
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7
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Setiawan A, Huang C, Mitrayana M. Development of non-contact foreign body imaging base on photoacoustic signal intensity measurement. J Appl Clin Med Phys 2024; 25:e14230. [PMID: 38014732 PMCID: PMC11087178 DOI: 10.1002/acm2.14230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 10/25/2023] [Accepted: 11/13/2023] [Indexed: 11/29/2023] Open
Abstract
BACKGROUND It is challenging to visually identify tiny and concealed foreign objects within the body due to their small size and subcutaneous location while they can cause infections. METHODS A non-contact photoacoustic system based on Rosencwaig-Gersho photoacoustic theory and dual modulator method is developed for detecting foreign objects in meat. RESULT The experiments conducted validate the successful development of this measurement technique with 10 μm spatial resolution and its corresponding mathematical model, demonstrating an 11% Mean Absolute Percentage Error (MAPE) in comparison to the experimental results. Dual modulator successfully regulates laser energy at MPE limit. CONCLUSION The utilization of non-contact photoacoustic signal intensity measurements enables the identification of foreign objects within the body. Further, the application of mathematical modelling can validate the measurement outcomes. These findings serve as a foundation for creating an affordable and straightforward foreign body detector.
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Affiliation(s)
- Andreas Setiawan
- Department of PhysicsUniversitas Kristen Satya WacanaSalatigaIndonesia
| | - Chia‐Yi Huang
- Department of Applied PhysicsTunghai UniversityTaichungTaiwan R.O.C
| | - Mitrayana Mitrayana
- Department of PhysicsFaculty of Mathematics and Natural Sciences Universitas Gadjah MadaSekip Utara BulaksumurYogyakartaIndonesia
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Pouymayou B, Perez-Haas Y, Allemann F, Saguner AM, Andratschke N, Guckenberger M, Tanadini-Lang S, Wilke L. Characterization of spatial integrity with active and passive implants in a low-field magnetic resonance linear accelerator scanner. Phys Imaging Radiat Oncol 2024; 30:100576. [PMID: 38644933 PMCID: PMC11031795 DOI: 10.1016/j.phro.2024.100576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/23/2024] Open
Abstract
Background and Purpose Standard imaging protocols can guarantee the spatial integrity of magnetic resonance (MR) images utilized in radiotherapy. However, the presence of metallic implants can significantly compromise this integrity. Our proposed method aims at characterizing the geometric distortions induced by both passive and active implants commonly encountered in planning images obtained from a low-field 0.35 T MR-linear accelerator (LINAC). Materials and Methods We designed a spatial integrity phantom defining 1276 control points and covering a field of view of 20x20x20 cm3. This phantom was scanned in a water tank with and without different implants used in hip and shoulder arthroplasty procedures as well as with active cardiac stimulators. The images were acquired with the clinical planning sequence (balanced steady-state free-precession, resolution 1.5x1.5x1.5 mm3). Spatial integrity was assessed by the Euclidian distance between the control point detected on the image and their theoretical locations. A first plane free of artefact (FPFA) was defined to evaluate the spatial integrity beyond the larger banding artefact. Results In the region extending up to 20 mm from the largest banding artefacts, the tested passive and active implants could cause distortions up to 2 mm and 3 mm, respectively. Beyond this region the spatial integrity was recovered and the image could be considered as unaffected by the implants. Conclusions We characterized the impact of common implants on a low field MR-LINAC planning sequence. These measurements could support the creation of extra margin while contouring organs at risk and target volumes in the vicinity of implants.
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Affiliation(s)
- Bertrand Pouymayou
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Yoel Perez-Haas
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Florin Allemann
- Department of Traumatology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Ardan M. Saguner
- Department of Cardiology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Nicolaus Andratschke
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Matthias Guckenberger
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Stephanie Tanadini-Lang
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Lotte Wilke
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
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Marcel AJ, Green JS, Porrino J, Katz LD, Medvecky MJ. Magnetic resonance imaging quality in the context of a knee-spanning external fixator placed inside the MR bore: a literature review. Skeletal Radiol 2024; 53:629-636. [PMID: 37955679 DOI: 10.1007/s00256-023-04505-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 10/29/2023] [Accepted: 10/30/2023] [Indexed: 11/14/2023]
Abstract
After emergent assessment of potentially limb-threatening injuries in knee dislocation or multi-ligament knee injury patients, magnetic resonance imaging is necessary to visualize ligamentous structures and plan for soft tissue repair. However, the application of a knee-spanning external fixator may introduce artifact and reduce overall image quality, which can limit the evaluation of soft tissue injury. As a result, the utility of MRI in the context of a knee-spanning external fixator has been called into question. Signal-to-noise ratio, contrast-to-noise ratio, and qualitative scales have been used to assess image quality of MRI in the context of a knee-spanning external fixator. Despite the potential for artifact, studies have demonstrated that useful diagnostic information may be obtained from MRI in the presence of an external fixator. This review examines the general principles of anatomical assessment, magnetic field strength, device composition and design, radiofrequency coil use, and MRI sequences and artifact reduction as they pertain to MRI in the presence of a knee-spanning external fixator.
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Affiliation(s)
- Aaron J Marcel
- Frank H. Netter MD School of Medicine at Quinnipiac University, North Haven, CT, USA.
| | - Joshua S Green
- Frank H. Netter MD School of Medicine at Quinnipiac University, North Haven, CT, USA
| | - Jack Porrino
- Yale School of Medicine, Department of Radiology, Musculoskeletal Imaging, New Haven, CT, USA
| | - Lee D Katz
- Yale School of Medicine, Department of Radiology, Musculoskeletal Imaging, New Haven, CT, USA
| | - Michael J Medvecky
- Yale School of Medicine, Department of Orthopaedics & Rehabilitation, New Haven, CT, USA
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10
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Lu Y, Cao R, Jiao S, Li L, Liu C, Hu H, Ma Z, Jiang Y, Chen J. A novel method of carotid artery wall imaging: black-blood CT. Eur Radiol 2024; 34:2407-2415. [PMID: 37736805 PMCID: PMC10957584 DOI: 10.1007/s00330-023-10247-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 07/20/2023] [Accepted: 08/04/2023] [Indexed: 09/23/2023]
Abstract
OBJECTIVES To evaluate the application of black-blood CT (BBCT) in carotid artery wall imaging and its accuracy in disclosing stenosis rate and plaque burden of carotid artery. METHODS A total of 110 patients underwent contrast-enhanced CT scan with two phases, and BBCT images were obtained using contrast-enhancement (CE)-boost technology. Two radiologists independently scored subjective image quality on black-blood computerized tomography (BBCT) images using a 4-point scale and then further analyzed plaque types. The artery stenosis rate on BBCT was measured and compared with CTA. The plaque burden on BBCT was compared with that on high-resolution intracranial vessel wall MR imaging (VW-MR imaging). The kappa value and intraclass correlation coefficient (ICC) were used for consistency analysis. The diagnostic accuracy of BBCT for stenosis rate and plaque burden greater than 50% was evaluated by AUC. RESULTS The subjective image quality scores of BBCT had good consistency between the two readers (ICC = 0.836, p < 0.001). BBCT and CTA had a good consistency in the identification of stenosis rate (p < 0.001). There was good consistency between BBCT and VW-MR in diagnosis of plaque burden (p < 0.001). As for plaque burden over 50%, BBCT had good sensitivity (93.10%) and specificity (73.33%), with an AUC of 0.950 (95%CI 0.838-0.993). Compared with CTA, BBCT had higher consistency with VW-MR in disclosing low-density plaques and mixed plaques (ICC = 0.931 vs 0.858, p < 0.001). CONCLUSIONS BBCT can not only display the carotid artery wall clearly but also accurately diagnose the stenosis rate and plaque burden of carotid artery. CLINICAL RELEVANCE STATEMENT Black-blood CT, as a novel imaging technology, can assist clinicians and radiologists in better visualizing the structure of the vessel wall and plaques, especially for patients with contraindication to MRI. KEY POINTS • Black-blood CT can clearly visualize the carotid artery wall and plaque burden. • Black-blood CT is superior to conventional CTA with more accurate diagnosis of the carotid stenosis rate and plaque burden features.
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Affiliation(s)
- Yao Lu
- The Key Laboratory of Geriatrics, Beijing Institute of GeriatricsInstitute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, People's Republic of China
- Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No.1, DaHua Road, Dong Dan, Beijing, 100730, People's Republic of China
| | - Ruoyao Cao
- Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No.1, DaHua Road, Dong Dan, Beijing, 100730, People's Republic of China
- Graduate School of Peking Union Medical College, Beijing, People's Republic of China
| | - Sheng Jiao
- Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No.1, DaHua Road, Dong Dan, Beijing, 100730, People's Republic of China
| | - Ling Li
- Department of Radiology, Beijing Shijitan Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Chao Liu
- Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No.1, DaHua Road, Dong Dan, Beijing, 100730, People's Republic of China
| | - Hailong Hu
- Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No.1, DaHua Road, Dong Dan, Beijing, 100730, People's Republic of China
| | - Zhuangfei Ma
- CT Clinical Research Department, CT Business Unit, Canon Medical Systems (China) CO., LTD., Beijing, People's Republic of China
| | - Yun Jiang
- Department of Neurology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Juan Chen
- Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No.1, DaHua Road, Dong Dan, Beijing, 100730, People's Republic of China.
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11
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Suzuki M, Onozato Y, Kondo J, Kyogoku S. Carotid artery plaque assessment using CT with iodine mapping. Eur Radiol 2024; 34:2405-2406. [PMID: 37801127 PMCID: PMC10957603 DOI: 10.1007/s00330-023-10276-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 10/07/2023]
Affiliation(s)
- Michimasa Suzuki
- Department of Radiology, Juntendo University, Uraysu Hospital, Chiba, Japan.
| | - Yusuke Onozato
- Department of Radiology, Juntendo University, Uraysu Hospital, Chiba, Japan
| | - Jiro Kondo
- Department of Radiology, Juntendo University, Uraysu Hospital, Chiba, Japan
| | - Shinsuke Kyogoku
- Department of Radiology, Juntendo University, Uraysu Hospital, Chiba, Japan
- Faculty of Health Science, Juntendo University, Tokyo, Japan
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12
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Rossi E, Emin S, Gubanski M, Gagliardi G, Hedman M, Villegas F. Contouring practices and artefact management within a synthetic CT-based radiotherapy workflow for the central nervous system. Radiat Oncol 2024; 19:27. [PMID: 38424642 PMCID: PMC11320867 DOI: 10.1186/s13014-024-02422-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 02/19/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND The incorporation of magnetic resonance (MR) imaging in radiotherapy (RT) workflows improves contouring precision, yet it introduces geometrical uncertainties when registered with computed tomography (CT) scans. Synthetic CT (sCT) images could minimize these uncertainties and streamline the RT workflow. This study aims to compare the contouring capabilities of sCT images with conventional CT-based/MR-assisted RT workflows, with an emphasis on managing artefacts caused by surgical fixation devices (SFDs). METHODS The study comprised a commissioning cohort of 100 patients with cranial tumors treated using a conventional CT-based/MR-assisted RT workflow and a validation cohort of 30 patients with grade IV glioblastomas treated using an MR-only workflow. A CE-marked artificial-intelligence-based sCT product was utilized. The delineation accuracy comparison was performed using dice similarity coefficient (DSC) and average Hausdorff distance (AHD). Artefacts within the commissioning cohort were visually inspected, classified and an estimation of thickness was derived using Hausdorff distance (HD). For the validation cohort, boolean operators were used to extract artefact volumes adjacent to the target and contrasted to the planning treatment volume. RESULTS The combination of high DSC (0.94) and low AHD (0.04 mm) indicates equal target delineation capacity between sCT images and conventional CT scans. However, the results for organs at risk delineation were less consistent, likely because of voxel size differences between sCT images and CT scans and absence of standardized delineation routines. Artefacts observed in sCT images appeared as enhancements of cranial bone. When close to the target, they could affect its definition. Therefore, in the validation cohort the clinical target volume (CTV) was expanded towards the bone by 3.5 mm, as estimated by HD analysis. Subsequent analysis on cone-beam CT scans showed that the CTV adjustment was enough to provide acceptable target coverage. CONCLUSION The tested sCT product performed on par with conventional CT in terms of contouring capability. Additionally, this study provides both the first comprehensive classification of metal artefacts on a sCT product and a novel method to assess the clinical impact of artefacts caused by SFDs on target delineation. This methodology encourages similar analysis for other sCT products.
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Affiliation(s)
- Elia Rossi
- Department of Radiation Oncology, Karolinska University Hospital, Solna, Sweden
| | - Sevgi Emin
- Radiotherapy Physics and Engineering, Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Solna, Sweden
| | - Michael Gubanski
- Department of Radiation Oncology, Karolinska University Hospital, Solna, Sweden
- Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Giovanna Gagliardi
- Radiotherapy Physics and Engineering, Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Solna, Sweden
- Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Mattias Hedman
- Department of Radiation Oncology, Karolinska University Hospital, Solna, Sweden
- Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Fernanda Villegas
- Radiotherapy Physics and Engineering, Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Solna, Sweden.
- Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden.
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Mutsuzaki H, Yashiro H, Kakehata M, Oyane A, Ito A. Femtosecond Laser Irradiation to Zirconia Prior to Calcium Phosphate Coating Enhances Osteointegration of Zirconia in Rabbits. J Funct Biomater 2024; 15:42. [PMID: 38391895 PMCID: PMC10889465 DOI: 10.3390/jfb15020042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/31/2024] [Accepted: 02/04/2024] [Indexed: 02/24/2024] Open
Abstract
Calcium phosphate (CaP) coating of zirconia and zirconia-based implants is challenging, due to their chemical instability and susceptibility to thermal and mechanical impacts. A 3 mol% yttrium-stabilized tetragonal zirconia polycrystal was subjected to femtosecond laser (FsL) irradiation to form micro- and submicron surface architectures, prior to CaP coating using pulsed laser deposition (PLD) and low-temperature solution processing. Untreated zirconia, CaP-coated zirconia, and FsL-irradiated and CaP-coated zirconia were implanted in proximal tibial metaphyses of male Japanese white rabbits for four weeks. Radiographical analysis, push-out test, alizarin red staining, and histomorphometric analysis demonstrated a much improved bone-bonding ability of FsL-irradiated and CaP-coated zirconia over CaP-coated zirconia without FsL irradiation and untreated zirconia. The failure strength of the FsL-irradiated and CaP-coated zirconia in the push-out test was 6.2-13.1-times higher than that of the CaP-coated zirconia without FsL irradiation and untreated zirconia. Moreover, the adhesion strength between the bone and FsL-irradiated and CaP-coated zirconia was as high as that inducing host bone fracture in the push-out tests. The increased bone-bonding ability was attributed to the micro-/submicron surface architectures that enhanced osteoblastic differentiation and mechanical interlocking, leading to improved osteointegration. FsL irradiation followed by CaP coating could be useful for improving the osteointegration of cement-less zirconia-based joints and zirconia dental implants.
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Affiliation(s)
- Hirotaka Mutsuzaki
- Center for Medical Science, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ibaraki 300-0394, Japan
- Department of Orthopaedic Surgery, Ibaraki Prefectural University of Health Sciences Hospital, 4773 Ami, Ibaraki 300-0331, Japan
| | - Hidehiko Yashiro
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Masayuki Kakehata
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Ayako Oyane
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Atsuo Ito
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
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Park JH, Kim DH, Chai JW, Kim HJ, Seo J, Son JY. [Imaging Evaluation of Early and Long-Term Complications Associated with the Postoperative Spine]. JOURNAL OF THE KOREAN SOCIETY OF RADIOLOGY 2024; 85:36-53. [PMID: 38362387 PMCID: PMC10864152 DOI: 10.3348/jksr.2023.0147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 01/14/2024] [Indexed: 02/17/2024]
Abstract
As the number of spinal surgeries being performed expands, the number of medical imaging procedures such as radiography, CT, and MRI is also increasing, and the importance of their interpretation is becoming more significant. Herein, we present the radiological findings of a variety of complications that can occur after spinal surgery and discuss how effectively and accurately they can be diagnosed through imaging. In particular, this study details the characteristic imaging findings specific to the early and long-term postoperative periods. Early complications of spinal surgery include improper placement of surgical instruments (instrument malpositioning), seromas, hematomas, pseudomeningoceles, and infections in the region surrounding the surgical site. Conversely, long-term complications may include osteolysis around surgical instruments, failure of fusion, adjacent segment disease, and the formation of epidural fibrosis or scar tissue. A precise understanding of the imaging assessments related to complications arising after spinal surgery is crucial to ensure timely and accurate diagnosis, which is necessary to achieve effective treatment.
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Hofman MBM, Lavini C, van der Zwan A, van Pul C, Muller SH, Stam MK, van der Graaf M, Kloeze C, van Nierop BJ, Kappert P, Kuijer JPA. MRI in patients with a cerebral aneurysm clip; review of the literature and incident databases and recommendations for the Netherlands. Phys Med 2024; 117:103187. [PMID: 38016215 DOI: 10.1016/j.ejmp.2023.103187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 11/07/2023] [Accepted: 11/23/2023] [Indexed: 11/30/2023] Open
Abstract
BACKGROUND In the past ferromagnetic cerebral aneurysm clips that are contraindicated for Magnetic Resonance Imaging (MRI) have been implanted. However, the specific clip model is often unknown for older clips, which poses a problem for individual patient management in clinical care. METHODS Literature and incident databases were searched, and a survey was performed in the Netherlands that identified time periods at which ferromagnetic and non-ferromagnetic clip models were implanted. Considering this information in combination with a national expert opinion, we describe an approach for risk assessment prior to MRI examinations in patients with aneurysm clips. The manuscript is limited to MRI at 1.5 T or 3 T whole body MRI systems with a horizontal closed bore superconducting magnet, covering the majority of clinical Magnetic Resonance (MR) systems. RESULTS From the literature a list of ferromagnetic clip models was obtained. The risk of movement or rotation of the clip due to the main magnetic field in case of a ferromagnetic clip is the main concern. In the incident databases records of four serious incidents due to aneurysm clips in MRI were found. The survey in the Netherlands showed that from 2000 onwards, no ferromagnetic clips were implanted in Dutch hospitals. DISCUSSION Recommendations are provided to help the MR safety expert assessing the risks when a patient with a cerebral aneurysm clip is referred for MRI, both for known and unknown clip models. This work was part of the development of a guideline by the Dutch Association of Medical Specialists.
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Affiliation(s)
- Mark B M Hofman
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, de Boelelaan 1118, 1081 HV Amsterdam, the Netherlands.
| | - Cristina Lavini
- Department of Radiology and Nuclear Medicine, Amsterdam UMC location AMC, de Boelelaan 1118, 1081 HV Amsterdam, the Netherlands
| | - Albert van der Zwan
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, Heidelberglaan 100, Utrecht, the Netherlands
| | - Carola van Pul
- Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Sara H Muller
- Maxima Medical Centre, Ds. Th. Fliednerstraat 1, 5631 BM Eindhoven, the Netherlands
| | - Mette K Stam
- Department of Radiology, LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Marinette van der Graaf
- Department of Medical Imaging, Radboud UMC, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, the Netherlands
| | - Carla Kloeze
- Catharina Hospital, Michelangelolaan 2, 5623 EJ Eindhoven, the Netherlands
| | - Bastiaan J van Nierop
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands
| | - Peter Kappert
- Department of Radiology, UMCG, Hanzeplein 1, 9713 GZ Groningen, the Netherlands
| | - Joost P A Kuijer
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, de Boelelaan 1118, 1081 HV Amsterdam, the Netherlands
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Khodarahmi I, Khanuja HS, Stern SE, Carrino JA, Fritz J. Compressed Sensing SEMAC MRI of Hip, Knee, and Ankle Arthroplasty Implants: A 1.5-T and 3-T Intrapatient Performance Comparison for Diagnosing Periprosthetic Abnormalities. AJR Am J Roentgenol 2023; 221:661-672. [PMID: 37255041 DOI: 10.2214/ajr.23.29380] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND. The utility of 3-T MRI for diagnosing joint disorders is established, but its performance for diagnosing abnormalities around arthroplasty implants is unclear. OBJECTIVE. The purpose of this study was to compare 1.5-T and 3-T compressed sensing slice encoding for metal artifact correction (SEMAC) MRI for diagnosing peri-prosthetic abnormalities around hip, knee, and ankle arthroplasty implants. METHODS. Forty-five participants (26 women, 19 men; mean age ± SD, 71 ± 14 years) with symptomatic lower extremity arthroplasty (hip, knee, and ankle, 15 each) prospectively underwent consecutive 1.5- and 3-T MRI examinations with intermediate-weighted (IW) and STIR compressed sensing SEMAC sequences. Using a Likert scale, three radiologists evaluated the presence or absence of periprosthetic abnormalities, including bone marrow edema-like signal, osteolysis, stress reaction/fracture, synovitis, and tendon abnormalities and collections; image quality; and visibility of anatomic structures. Statistical analysis included nonparametric comparison and interchangeability testing. RESULTS. For diagnosing periprosthetic abnormalities, 1.5-T and 3-T compressed sensing SEMAC MRI were interchangeable. Across all three joints, 3-T MRI had lower noise than 1.5-T MRI (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [range, 2-5 and 3-5] vs 3 and 3 [range, 2-5 and 2-4]; p < .01 for both), sharper edges (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [both ranges, 2-5] vs 3 and 3 [range, 2-4 and 2-5]; p < .02 and p < .05), and more effective metal artifact reduction (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [range, 3-5 and 2-5] vs 4 and 4 [both ranges, 3-5]; p < .02 and p = .72). Agreement was moderate to substantial for image contrast (IW and STIR, 0.66 and 0.54 [95% CI, 0.41-0.91 and 0.29-0.80]; p = .58 and p = .16) and joint capsule visualization (IW and STIR, 0.57 and 0.70 [range, 0.32-0.81 and 0.51-0.89]; p = .16 and p = .19). The bone-implant interface was more visible at 1.5 T (median IW and STIR scores, 4 and 4 [both ranges, 2-5] at 1.5 T vs 3 and 3 [both ranges, 2-5] at 3 T; p = .08 and p = .58), but periprosthetic tissues had superior visibility at 3 T (IW and STIR, 4 and 4 [both ranges, 3-5] at 3 T vs 4 and 4 [ranges, 2-5 and 3-5] at 1.5 T; p = .07 and p = .19). CONCLUSION. Optimized 1.5-T and 3-T compressed sensing SEMAC MRI are interchangeable for diagnosing periprosthetic abnormalities, although metallic artifacts are larger at 3 T. CLINICAL IMPACT. With compressed sensing SEMAC MRI, lower extremity arthroplasty implants can be imaged at 3 T rather than 1.5 T.
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Affiliation(s)
- Iman Khodarahmi
- Department of Radiology, NYU Grossman School of Medicine, 660 1st Ave, 3rd Fl, Rm 313, New York, NY 10016
| | - Harpal S Khanuja
- Department of Orthopaedic Surgery, Johns Hopkins School of Medicine, Baltimore, MD
| | - Steven E Stern
- Centre for Data Analytics, Bond University, Gold Coast, Australia
| | - John A Carrino
- Department of Radiology, Hospital for Special Surgery, New York, NY
| | - Jan Fritz
- Department of Radiology, NYU Grossman School of Medicine, 660 1st Ave, 3rd Fl, Rm 313, New York, NY 10016
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Sacher SE, Koff MF, Tan ET, Burge A, Potter HG. The role of advanced metal artifact reduction MRI in the diagnosis of periprosthetic joint infection. Skeletal Radiol 2023:10.1007/s00256-023-04483-5. [PMID: 37875571 PMCID: PMC11039568 DOI: 10.1007/s00256-023-04483-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 10/26/2023]
Abstract
Identification and diagnosis of periprosthetic joint infection (PJI) are challenging, requiring a multi-disciplinary approach involving clinical evaluation, laboratory tests, and imaging studies. MRI is advantageous to alternative imaging techniques due to superior soft tissue contrast and absence of ionizing radiation. However, the presence of metallic implants can cause signal loss and artifacts. Metal artifact suppression (MARS) MRI techniques have been developed that mitigate metal artifacts and improve periprosthetic soft tissue visualization. This paper provides a review of the various MARS MRI techniques, their clinical applicability and accuracy in PJI diagnosis and evaluation, and current challenges and future perspectives.
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Affiliation(s)
- Sara E Sacher
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th St, New York, NY, 10021, USA.
| | - Matthew F Koff
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th St, New York, NY, 10021, USA
| | - Ek T Tan
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th St, New York, NY, 10021, USA
| | - Alissa Burge
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th St, New York, NY, 10021, USA
| | - Hollis G Potter
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th St, New York, NY, 10021, USA.
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Zhao BYH, Khan NA, Wichuk S, Sommerfeldt MF, Panu A, Jaremko JL, Hui C. The use of slice encoding for metal artifact correction (SEMAC) sequencing improves the diagnostic evaluation of graft integrity following anterior cruciate ligament reconstruction. J ISAKOS 2023; 8:318-324. [PMID: 37127091 DOI: 10.1016/j.jisako.2023.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 03/24/2023] [Accepted: 04/19/2023] [Indexed: 05/03/2023]
Abstract
OBJECTIVES To determine whether magnetic resonance imaging (MRI) with metal artifact reduction sequencing is superior to conventional knee MRI in the evaluation of an injured anterior cruciate ligament (ACL) graft, where visualisation on conventional MRI can be limited by the metal artifact from fixation devices. METHODS Eighteen patients underwent conventional MRI sequence (proton density fat saturated [PDFS]) and two types of metal artifact reduction sequencing MRI (WARP, slice encoding for metal artifact correction (SEMAC); Siemens) following a secondary injury to their ACL reconstructed knee. Six raters with experience in knee MRI evaluation reviewed sagittal PDFS, WARP, and SEMAC sequences, providing semi-quantitative grades for visualisation and diagnostic confidence assessing the ACL, posterior cruciate ligament , menisci, tibial and femoral tunnel margins, and articular cartilage. Intra-class correlation coefficients for inter-rater reliability were evaluated. The 6-rater mean scores for the visualisation and diagnostic confidence derived from each sequence were compared using the Friedman test for multiple paired samples. RESULTS No statistically significant difference in the ACL visualisation among the sequences was found (p = 0.193). Further, a subgroup analysis was performed in cases evaluated as "moderately blurry" or "indistinct ACL visualisation" on PDFS (58% of cases). SEMAC significantly improved diagnostic confidence in ACL visualisation (p = 0.041) and ACL graft rupture (p = 0.044) compared to PDFS. There was no statistically significant difference in the inter-observer reliability between sequences. The WARP sequence added 2.84 ± 0.69 min, while SEMAC added 2.95 ± 0.40 min to the standard knee MRI scan time. CONCLUSION use of the SEMAC metal reduction sequence significantly improved diagnostic accuracy and confidence in the detection of ACL graft rupture in cases where the ACL was moderately blurry or indistinct on the PDFS sequence. This sequence should be considered as an adjunct to conventional PDFS in cases where graft visualisation is limited by the metal artifact from fixation devices. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Brandon Y H Zhao
- Division of Orthopaedic Surgery, University of Alberta, Edmonton, AB, T5H 3V9, Canada.
| | - Nabil A Khan
- Division of Orthopaedic Surgery, University of Alberta, Edmonton, AB, T5H 3V9, Canada
| | - Stephanie Wichuk
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, T6G 2B7, Canada
| | - Mark F Sommerfeldt
- Division of Orthopaedic Surgery, University of Alberta, Edmonton, AB, T5H 3V9, Canada; Glen Sather Sports Medicine Clinic, University of Alberta, Edmonton, AB, T6G 1Z1, Canada
| | - Anukul Panu
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, T6G 2B7, Canada
| | - Jacob L Jaremko
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, T6G 2B7, Canada
| | - Catherine Hui
- Division of Orthopaedic Surgery, University of Alberta, Edmonton, AB, T5H 3V9, Canada
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Hilmi A, Patel S, Mirza K, Galicia JC. Efficacy of imaging techniques for the diagnosis of apical periodontitis: A systematic review. Int Endod J 2023; 56 Suppl 3:326-339. [PMID: 37067066 DOI: 10.1111/iej.13921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 03/31/2023] [Accepted: 04/13/2023] [Indexed: 04/18/2023]
Abstract
BACKGROUND Apical periodontitis (AP) is a chronic inflammatory response of microbial aetiology. Pathological changes associated with AP may not be visible on radiographic images and may linger without causing any symptoms. Clinicians rely mostly on clinical examination and imaging techniques to establish a diagnosis. OBJECTIVES The aim of this review was to answer the following question using the PICO format: In the adult human permanent dentition (P), what is the efficacy of diagnostic imaging of the periapical tissues (I) using histopathology as a reference standard (C) in the diagnosis of apical periodontitis, in terms of diagnostic accuracy (O). METHODS MEDLINE, EMBASE, Scopus and Cochrane Library were searched for English articles published through October 2021. At least two independent reviewers evaluated the study design, imaging modality used, histopathological assessment, outcome measures, results and conclusions for each article. The risk of bias was assessed using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. RESULTS The initial search strategy identified 544 articles. Seven articles were included for analysis in the final review, all of which involved tissue samples obtained from cadavers. No clinical studies were identified that met the eligibility criteria. A consistently low sensitivity score and negative predictive value were reported for periapical radiography, especially in comparison to CBCT, which scored highly. Both modalities achieved high scores for specificity and positive predictive value. Diagnostic accuracy of CBCT was lower for root-filled teeth in comparison to non-root-filled teeth. DISCUSSION Assessment of the periapical tissues using periapical radiographs was shown to have a low to moderate agreement with the histopathological assessment. CBCT was reported to be more accurate than PR and demonstrated a good agreement with histopathology, especially for non-root-filled teeth. CONCLUSIONS This review identified a need for greater standardization in methodology and reporting, and as the findings are based on cadaver studies, their clinical relevance must be interpreted with caution. REGISTRATION PROSPERO (CRD42021272147).
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Affiliation(s)
- Ali Hilmi
- Department of Endodontology, King's College London Dental Institute, London, UK
| | - Shanon Patel
- Department of Endodontology, King's College London Dental Institute, London, UK
- Specialist Practice, London, UK
| | - Kazim Mirza
- Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, California, USA
| | - Johnah C Galicia
- Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, California, USA
- Department of Endodontics, Eastman Dental Institute, University College of London, London, UK
- College of Dentistry, Manila Central University, Caloocan City, Philippines
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Bohner L, Dirksen D, Hanisch M, Sesma N, Kleinheinz J, Meier N. Artifacts in magnetic resonance imaging of the head and neck: Unwanted effects caused by implant-supported restorations fabricated with different alloys. J Prosthet Dent 2023:S0022-3913(23)00554-1. [PMID: 37739882 DOI: 10.1016/j.prosdent.2023.08.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 08/20/2023] [Accepted: 08/21/2023] [Indexed: 09/24/2023]
Abstract
STATEMENT OF PROBLEM Implant-supported restorations may cause artifacts in magnetic resonance imaging (MRI) of the head and neck area. However, the effect of different alloys remains unclear. PURPOSE The purpose of this in vitro study was to assess artifacts in head and neck MRI caused by implant-supported restorations with different alloys. MATERIAL AND METHODS Three dry mandibles were prepared to receive bilateral dental implants at the second premolar and second molar sites. Different alloy combinations were evaluated: titanium implants+cobalt chromium restorations; titanium-zirconium implants+cobalt chromium restorations; and zirconia implants+ceramic restorations. Specimens were imaged by using a 3-Tesla magnetic resonance scanner system (Achieva 3.0T TX; Philips GmbH) with a turbo-spin-echo sequence. Scan protocols were adjusted to optimize metal artifact reduction and shorten scan time. Artifact volumes were assessed and statistically analyzed by using the Kruskal-Wallis and Spearman tests (α=.05). RESULTS A statistically significant difference was found among artifact volume caused by different materials (P=.002). The presence of titanium alloy was correlated with the artifact volume (r=-.87). Artifacts were greater for titanium and fewer for titanium-zirconium alloys, whereas zirconia implants found only minimal artifacts. CONCLUSIONS The dimension of artifacts produced by implant-supported restorations varied according to the material.
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Affiliation(s)
- Lauren Bohner
- Research Associate, Department of Cranio-Maxillofacial Surgery, University Hospital Muenster, Muenster, Germany.
| | - Dieter Dirksen
- Professor, Department of Prosthodontics and Biomaterials, University Hospital Muenster, Muenster, Germany
| | - Marcel Hanisch
- Research Associate, Department of Cranio-Maxillofacial Surgery, University Hospital Muenster, Muenster, Germany
| | - Newton Sesma
- Professor, Department of Prosthodontics, School of Dentistry, University of São Paulo (USP), São Paulo, Brazil
| | - Johannes Kleinheinz
- Professor, Department of Cranio-Maxillofacial Surgery, University Hospital Muenster, Muenster, Germany
| | - Norbert Meier
- Research Associate, Department of Radiology, University Hospital Muenster, Muenster, Germany
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Longo UG, De Salvatore S, Zollo G, Calabrese G, Piergentili I, Loppini M, Denaro V. Magnetic resonance imaging could precisely define the mean value of tendon thickness in partial rotator cuff tears. BMC Musculoskelet Disord 2023; 24:718. [PMID: 37689653 PMCID: PMC10492299 DOI: 10.1186/s12891-023-06756-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 07/25/2023] [Indexed: 09/11/2023] Open
Abstract
PURPOSE Rotator Cuff (RC) lesions are classified in full-thickness and partial-thickness tears (PTRCTs). To our knowledge, no studies investigated the mean size of shoulder tendons in healthy and PTRCT patients using MRI scans. The aim of the study was to provide data to obtain and compare the mean value of tendon sizes in healthy and PTRCTs groups. METHODS From 2014 to 2020, 500 were included in the study. They were divided into two groups: Group 1 (100 subjects) was composed of people positive for partial-thickness rotator cuff tears (PTRCTs), while the 400 subjects in Group 2 were negative for PTRCTs. RESULTS Overall, of the patients included in the study, 231 were females and 269 were males. The mean age of the patients was 49 ± 12.7 years. The mean thickness of the supraspinatus tendon (SSP) was 5.7 ± 0.6 mm in Group 1, 5.9 ± 0.6 mm in Group 2 (p < 0.001). The mean length of the ISP tendon was 27.4 ± 3.2 mm in Group 1, 28.3 ± 3.8 mm in Group 2 (p = 0.004). The mean width of the SSP tendon was 17 ± 1.6 mm in Group 1, 17.6 ± 2 mm in Group 2 (p = 0.004). The mean width of the infraspinatus tendon (ISP) tendon was 17.7 ± 1.4 mm in Group 1, 18.3 ± 2.1 mm in Group 2 (p = 0.02). CONCLUSION The anatomical data present in this paper may serve as a tool for surgeons to properly manage PTRCTs. The findings of the present study aimed to set the first step towards reaching unanimity to establish international cut-off values to perform surgery. Additionally, they could widely increase diagnostic accuracy, improving both conservative and surgical approaches. Lastly, further clinical trials using more accurate diagnostic MRI tools are required to better define the anatomical differences between PTRCT and healthy patients. LEVEL OF EVIDENCE Level II, Retrospective Comparative Trial.
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Affiliation(s)
- Umile Giuseppe Longo
- Research Unit of Orthopaedic and Trauma Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, Roma, 200 - 00128 Italy
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma, 21 - 00128 Italy
| | - Sergio De Salvatore
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma, 21 - 00128 Italy
- Department of Orthopedics, Children’s Hospital Bambino Gesù, Palidoro, Rome, 00165 Italy
| | - Giuliano Zollo
- Research Unit of Orthopaedic and Trauma Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, Roma, 200 - 00128 Italy
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma, 21 - 00128 Italy
| | - Giovanni Calabrese
- Research Unit of Orthopaedic and Trauma Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, Roma, 200 - 00128 Italy
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma, 21 - 00128 Italy
| | - Ilaria Piergentili
- Research Unit of Orthopaedic and Trauma Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, Roma, 200 - 00128 Italy
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma, 21 - 00128 Italy
| | - Mattia Loppini
- IRCCS Humanitas Research Hospital, Rozzano, 20089 Italy
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, 20072 Italy
| | - Vincenzo Denaro
- Research Unit of Orthopaedic and Trauma Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, Roma, 200 - 00128 Italy
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, Roma, 21 - 00128 Italy
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Yang JY, Hsieh TJ, Chen CKH, Lin CH, Chou YC. Comparison of Short-Tau Inversion Recovery With Short-Tau Inversion Recovery-Slice Encoding for Metal Artifact Correction for Spine Imaging at 1.5 T in the Setting of Metallic Implants. J Comput Assist Tomogr 2023; 47:811-819. [PMID: 37707413 DOI: 10.1097/rct.0000000000001472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVE To compare the image quality of short-tau inversion recovery (STIR) and the STIR-slice encoding for metal artifact correction (SEMAC) sequence for postsurgery spine magnetic resonance imaging (MRI). METHODS Twenty-nine patients with metallic spinal implants who underwent spinal 1.5 T MRI with STIR and STIR-SEMAC sequences between July 2016 and November 2020 were retrospectively enrolled. Qualitative assessments were performed using 5-point scales; higher scores indicated better image quality. For screw metal artifact analysis, scores were obtained for artifacts on vertebral bodies and neural foramina, screw artifact widths, and bone marrow signal intensities. For patient-based analysis, scores were obtained for imaging quality and fat suppression quality, signal intensity, and cerebrospinal fluid noise. A paired t test was performed for statistical analyses. RESULTS We analyzed 163 screws in 29 patients. In the screw metal artifact analysis, the vertebral body and neural foramen scores were significantly higher for the STIR-SEMAC images than for the STIR (all P < 0.001). The artifact width in the STIR-SEMAC images (9.8 ± 3.4 mm) was significantly smaller than that in the STIR images (16.0 ± 4.7 mm, P < 0.001). In patient-based analysis, the fat suppression and imaging quality scores were significantly higher for the STIR-SEMAC images than for the STIR images (all P < 0.001). The cerebrospinal fluid signal intensity, noise, and signal-to-noise ratios were significantly higher for the STIR images (all P < 0.005). CONCLUSIONS Short-tau inversion recovery-SEMAC sequences provide good metallic artifact reduction and fat suppression for postsurgery spine 1.5 T MRI.
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Affiliation(s)
- Jie-Yu Yang
- From the Department of Medical Imaging, Chi Mei Medical Center, Tainan
| | - Tsyh-Jyi Hsieh
- Department of Radiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | | | - Chien-Hung Lin
- From the Department of Medical Imaging, Chi Mei Medical Center, Tainan
| | - Yi-Chen Chou
- From the Department of Medical Imaging, Chi Mei Medical Center, Tainan
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23
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Amann N, Johnson S, Chagarlamudi K, Gupta A, Faraji N. Scheduling Musculoskeletal MRI for Patients With Metallic Hardware: Initial Observations on Decreasing Nondiagnostic and Repeat Examinations at a Multisite Academic Medical Center. Curr Probl Diagn Radiol 2023; 52:327-329. [PMID: 37037716 DOI: 10.1067/j.cpradiol.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/16/2023] [Indexed: 04/12/2023]
Abstract
OBJECTIVE As healthcare delivery systems expand to include multiple imaging centers, the process of scheduling patients at the site which best meets their needs continues to become more complex. This quality improvement study aims to create a protocol for patients with metallic hardware at sites with metallic artifact reduction sequences (MARS), increasing the proportion of exams that are diagnostic and reducing the need for repeat imaging. MATERIALS AND METHODS The study population included 322 patients with metallic hardware receiving an MRI at a large multisite healthcare system, divided into a pre-intervention and postintervention cohort. A retrospective PACS query was performed using several keywords in musculoskeletal MRI reports indicating the presence of metallic hardware. This cohort was studied to better understand the existing system failures. An intervention was then implemented by meeting with the departmental RIS and scheduling teams to discuss workflow when scheduling exams for patients with metallic hardware System changes were implemented and results were again studied retrospectively. RESULTS Before protocol implementation, 134/244 (55%) of exams were performed at sites with metallic artifact reduction sequences which improved to 54 of 78 (69%) in the postintervention cohort (P = 0.02). Additionally, the number of exams performed on 3T MRI machines pre-intervention was 14 of 244 (5.7%) compared to 1 of 78 (1.2%) postintervention (P = 0.13). The rate of nondiagnostic exams in the preintervention cohort was significantly higher at 41 of 244 (16.8%) when compared to the postintervention cohort at 4 of 78 (5.1% P = 0.01). CONCLUSIONS The implementation of this quality improvement protocol reduced the rate of nondiagnostic MSK MRI exams and reduced the inappropriate use of 3T scanners, ultimately saving time and cost for both patients and the health care system.
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Affiliation(s)
- Nathan Amann
- Case Western Reserve University School of Medicine, Cleveland, OH.
| | - Shaun Johnson
- Case Western Reserve University School of Medicine, Cleveland, OH
| | - Kaushik Chagarlamudi
- Case Western Reserve University School of Medicine, Cleveland, OH; Department of Radiology, University Hospitals, Cleveland, OH
| | - Amit Gupta
- Case Western Reserve University School of Medicine, Cleveland, OH; Department of Radiology, University Hospitals, Cleveland, OH
| | - Navid Faraji
- Case Western Reserve University School of Medicine, Cleveland, OH; Department of Radiology, University Hospitals, Cleveland, OH
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24
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Fritz J, Rashidi A, de Cesar Netto C. Magnetic Resonance Imaging of Total Ankle Arthroplasty: State-of-The-Art Assessment of Implant-Related Pain and Dysfunction. Foot Ankle Clin 2023; 28:463-492. [PMID: 37536814 DOI: 10.1016/j.fcl.2023.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Total ankle arthroplasty (TAA) is an effective alternative for treating patients with end-stage ankle degeneration, improving mobility, and providing pain relief. Implant survivorship is constantly improving; however, complications occur. Many causes of pain and dysfunction after total ankle arthroplasty can be diagnosed accurately with clinical examination, laboratory, radiography, and computer tomography. However, when there are no or inconclusive imaging findings, magnetic resonance imaging (MRI) is highly accurate in identifying and characterizing bone resorption, osteolysis, infection, osseous stress reactions, nondisplaced fractures, polyethylene damage, nerve injuries and neuropathies, as well as tendon and ligament tears. Multiple vendors offer effective, clinically available MRI techniques for metal artifact reduction MRI of total ankle arthroplasty. This article reviews the MRI appearances of common TAA implant systems, clinically available techniques and protocols for metal artifact reduction MRI of TAA implants, and the MRI appearances of a broad spectrum of TAA-related complications.
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Affiliation(s)
- Jan Fritz
- Department of Orthopedic Surgery, Division of Foot and Ankle Surgery, Duke University, Durham, NC, USA.
| | - Ali Rashidi
- Division of Musculoskeletal Radiology, Department of Radiology, NYU Grossman School of Medicine, 660 1st Ave, 3rd Floor, Rm 313, New York, NY 10016, USA
| | - Cesar de Cesar Netto
- Department of Radiology, Molecular Imaging Program at StanDepartment of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA, USA
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25
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Perry JL, Schleif E, Fang XM, Briley PM, McCarlie VW. Can Velopharyngeal MRI be Used in Individuals with Orthodontic Devices? Cleft Palate Craniofac J 2023:10556656231194511. [PMID: 37554050 DOI: 10.1177/10556656231194511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023] Open
Abstract
OBJECTIVE To evaluate the influence of common pediatric orthodontic appliances on velopharyngeal (VP) MRI and to compare MR image sequences to determine if sequence parameters impact the visibility of key VP structures commonly assessed in clinical VP MRI. DESIGN Participants undergoing orthodontic treatment completed a VP MRI study. Level of distortion caused by orthodontic devices on 8 anatomical sites of interest and using variable MRI sequences was evaluated. SETTING Single institution. PARTICIPANTS Nineteen participants undergoing orthodontic treatment. MAIN OUTCOME Level of distortion caused by metal artifacts and MR sequence used. RESULTS The results of this study demonstrate that appliances such as hyrax palatal expanders and braces with stainless steel brackets are acceptable for a VP MRI, while class II corrector springs are not recommended. The HASTE MRI sequence with 2D imaging techniques should be utilized if the child has orthodontic devices, while FSE and 3D imaging techniques are not recommended. The presence of wire spring coils and molar bands are likely to not to interfere with the MRI evaluation. CONCLUSIONS Findings from this study suggest that the presence of orthodontic appliances does not hinder visualization of all velopharyngeal structures during an MRI. Therefore, careful consideration must be made prior to disqualifying or recommending patients for VP MRI.
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Affiliation(s)
- Jamie L Perry
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, NC, USA
| | | | - Xiang Ming Fang
- Department of Biostatistics, East Carolina University, Greenville, NC, USA
| | - Patrick M Briley
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, NC, USA
| | - V Wallace McCarlie
- Department of Pediatric Dentistry & Orthodontics and Dentofacial Orthopedics, Division or Orthodontics and Dentofacial Orthopedics, East Carolina University, Greenville, NC, USA
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26
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Canzi P, Carlotto E, Simoncelli A, Lafe E, Scribante A, Minervini D, Nardo M, Malpede S, Chiapparini L, Benazzo M. The usefulness of the O-MAR algorithm in MRI skull base assessment to manage cochlear implant-related artifacts. ACTA OTORHINOLARYNGOLOGICA ITALICA : ORGANO UFFICIALE DELLA SOCIETA ITALIANA DI OTORINOLARINGOLOGIA E CHIRURGIA CERVICO-FACCIALE 2023; 43:273-282. [PMID: 37488991 PMCID: PMC10366562 DOI: 10.14639/0392-100x-n2434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/02/2023] [Indexed: 07/26/2023]
Abstract
Objective To assess artifact size and MRI visibility when applying the "Orthopedic-Metal Artifact Reduction" (O-MAR) algorithm for cochlear implant (CI) scanning. Methods Two volunteers were submitted to 1.5 T MRI with an Ultra 3D CI receiver stimulator placed on their head. Four angular CI orientations were adopted: 90, 120, 135 and 160 degrees. Volunteers were scanned in each condition using T1w and T2w TSE sequences, as well as O-MAR sequences, in both axial and coronal planes. Quantitative comparisons were made of signal void and penumbra extent. Additionally, qualitative evaluations of global image quality, MRI readability with respect to 12 anatomical structures and visibility through the penumbra were undertaken. Results After application of the O-MAR protocol, the radius of the signal void reduced from 50.76 mm to 45.43 mm and from 49.22 mm to 40.15 mm on T1w and T2w TSE axial sequences, respectively (p < 0.05). Qualitatively, sequences acquired with O-MAR produced better outcomes in terms of image quality and anatomical depiction. Despite the area of the penumbra being increased for the O-MAR protocol, visibility through penumbra was improved. Conclusions Application of O-MAR may provide a complementary strategy to those already in use to obtain diagnostically useful MRI examinations in the presence of a CI, especially in case of skull base diseases requiring MRI monitoring.
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Affiliation(s)
- Pietro Canzi
- Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy
- Department of Otorhinolaryngology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Elena Carlotto
- Department of Otorhinolaryngology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Anna Simoncelli
- Department of Diagnostic Radiology and Interventional Radiology and Neuroradiology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Elvis Lafe
- Department of Diagnostic Radiology and Interventional Radiology and Neuroradiology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Andrea Scribante
- Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy
- Unit of Orthodontics and Pediatric Dentistry, Section of Dentistry, Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy
| | - Domenico Minervini
- Department of Otorhinolaryngology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Matteo Nardo
- Department of Otorhinolaryngology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Stefano Malpede
- Department of Otorhinolaryngology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Luisa Chiapparini
- Department of Diagnostic Radiology and Interventional Radiology and Neuroradiology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Marco Benazzo
- Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy
- Department of Otorhinolaryngology, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
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27
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Sennimalai K, Selvaraj M, Kharbanda OP, Kandasamy D, Mohaideen K. MRI-based cephalometrics: a scoping review of current insights and future perspectives. Dentomaxillofac Radiol 2023; 52:20230024. [PMID: 36809112 PMCID: PMC10304848 DOI: 10.1259/dmfr.20230024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 02/12/2023] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE This review aims to explore the current status of magnetic resonance imaging (MRI) as a cephalometric tool, summarize the equipment design and methods, and propose recommendations for future research. METHODS A systematic search was conducted in electronic databases, including PubMed, Ovid MEDLINE, Scopus, Embase, Web of Science, EBSCOhost, LILACS, and Cochrane Library, using broad search terms. The articles published in any language till June 2022 were considered. Cephalometric studies conducted using the MRI dataset on human participants, phantom or cadaver were included. Two independent reviewers assessed the final eligible articles using the quality assessment score (QAS). RESULTS Nine studies were included in the final assessment. Studies used various methods, including 1.5 T or 3 T MRI systems and 3D or 2D MRI datasets. Among the imaging sequences, T1-weighted, T2-weighted and black bone MR images were used for cephalometric analysis. In addition, the reference standards varied among studies, such as traditional 2D cephalogram, cone-beam CT and phantom measurements. The mean QAS of all the included studies was 79% (± 14.4%). The main limitation of most studies was the small sample size and the heterogeneity of the methods, statistical tools used, and metric outcomes assessed. CONCLUSIONS Despite the heterogeneity and lack of metrological evidence on the effectiveness of MRI-based cephalometric analysis, the preliminary results demonstrated by in vivo and in vitro studies are encouraging. However, future studies exploring MRI sequences specific to cephalometric diagnosis are required for wider adoption of this technique in routine orthodontic practice.
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Affiliation(s)
- Karthik Sennimalai
- Department of Orthodontics, All India Institute of Medical Sciences, Jammu, 184120, Jammu & Kashmir, India
| | - Madhanraj Selvaraj
- Division of Orthodontics and Dentofacial Orthopedics, Department of Dentistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India
| | | | - Devasenathipathy Kandasamy
- Department of Radiodiagnosis and Interventional Radiology, All India Institute of Medical Sciences, New Delhi, 110029, Delhi, India
| | - Kaja Mohaideen
- Department of Dentistry, All India Institute of Medical Sciences, Bilaspur, 174001, Himachal Pradesh, India
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Cederberg KB, Iyer RS, Chaturvedi A, McCarville MB, McDaniel JD, Sandberg JK, Shammas A, Sharp SE, Nadel HR. Imaging of pediatric bone tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper. Pediatr Blood Cancer 2023; 70 Suppl 4:e30000. [PMID: 36250990 PMCID: PMC10661611 DOI: 10.1002/pbc.30000] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/08/2022]
Abstract
Malignant primary bone tumors are uncommon in the pediatric population, accounting for 3%-5% of all pediatric malignancies. Osteosarcoma and Ewing sarcoma comprise 90% of malignant primary bone tumors in children and adolescents. This paper provides consensus-based recommendations for imaging in children with osteosarcoma and Ewing sarcoma at diagnosis, during therapy, and after therapy.
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Affiliation(s)
- Kevin B. Cederberg
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ramesh S. Iyer
- Department of Radiology, Seattle Children’s Hospital, Seattle, WA
| | - Apeksha Chaturvedi
- Division of Pediatric Radiology, Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY
| | - MB McCarville
- Department of Diagnostic Imaging, St Jude Children’s Research Hospital, Memphis, TN
| | - Janice D. McDaniel
- Department of Pediatric Interventional Radiology, Akron Children’s Hospital, Akron, OH and Department of Radiology, Northeast Ohio Medical University, Rootstown, OH
| | - Jesse K. Sandberg
- Department of Pediatric Radiology, Lucile Packard Children’s Hospital, Stanford University, Stanford, CA
| | - Amer Shammas
- Division of Nuclear Medicine, Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, Toronto, OH, Canada
| | - Susan E. Sharp
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Helen R. Nadel
- Department of Pediatric Radiology, Lucile Packard Children’s Hospital, Stanford University, Stanford, CA
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Kumar N, Alathur Ramakrishnan S, Lopez KG, Wang N, Madhu S, Vellayappan BA, Tpd Hallinan J, Fuh JYH, Kumar AS. Design and 3D printing of novel titanium spine rods with lower flexural modulus and stiffness profile with optimised imaging compatibility. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2023; 32:1953-1965. [PMID: 37052651 DOI: 10.1007/s00586-023-07674-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 03/07/2023] [Accepted: 03/18/2023] [Indexed: 04/14/2023]
Abstract
PURPOSE To manufacture and test 3D printed novel design titanium spine rods with lower flexural modulus and stiffness compared to standard solid titanium rods for use in metastatic spine tumour surgery (MSTS) and osteoporosis. METHODS Novel design titanium spine rods were designed and 3D printed. Three-point bending test was performed to assess mechanical performance of rods, while a French bender was used to assess intraoperative rod contourability. Furthermore, 3D printed spine rods were tested for CT & MR imaging compatibility using phantom setup. RESULTS Different spine rod designs generated includes shell, voronoi, gyroid, diamond, weaire-phelan, kelvin, and star. Tests showed 3D printed rods had lower flexural modulus with reduction ranging from 2 to 25% versus standard rod. Shell rods exhibited highest reduction in flexural modulus of 25% (~ 77.4 GPa) and star rod exhibited lowest reduction in flexural modulus of 2% (100.8GPa). 3D printed rod showed reduction in stiffness ranging from 40 to 59%. Shell rod displayed highest reduction in stiffness of 59% (179.9 N/mm) and gyroid had least reduction in stiffness of 40% (~ 259.2 N/mm). Rod bending test showed that except gyroid, other rod designs demonstrated lesser bending difficulty versus standard rod. All 3D printed rods demonstrated improved CT/MR imaging compatibility with reduced artefacts versus standard rod. CONCLUSION By utilising novel design approach, we successfully generated a spine rod design portfolio with lower flexural modulus/stiffness profile and better CT/MR imaging compatibility for potential use in MSTS/other conditions such as osteoporosis. Thus, exploration of new rod designs in surgical application could enhance treatment outcome and improve quality of life for patients.
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Affiliation(s)
- Naresh Kumar
- Department of Orthopaedic Surgery, National University Health System, Level 11 Tower Block, 1E, Lower Kent Ridge Road, Singapore, 119228, Singapore.
| | - Sridharan Alathur Ramakrishnan
- Department of Orthopaedic Surgery, National University Health System, Level 11 Tower Block, 1E, Lower Kent Ridge Road, Singapore, 119228, Singapore
| | - Keith Gerard Lopez
- Department of Orthopaedic Surgery, National University Health System, Level 11 Tower Block, 1E, Lower Kent Ridge Road, Singapore, 119228, Singapore
| | - Niyou Wang
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - Sirisha Madhu
- Department of Orthopaedic Surgery, National University Health System, Level 11 Tower Block, 1E, Lower Kent Ridge Road, Singapore, 119228, Singapore
| | - Balamurugan A Vellayappan
- Department of Radiation Oncology, National University Health System, Level 7 Tower Block, 1E, Lower Kent Ridge Road, Singapore, 119228, Singapore
| | - James Tpd Hallinan
- Department of Diagnostic Imaging, National University Hospital, Level 2 National University Hospital Main Building, 5 Lower Kent Ridge Rd, Singapore, 119074, Singapore
| | - Jerry Ying Hsi Fuh
- Department of Mechanical Engineering, National University of Singapore, #04-18 Block EA, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - A Senthil Kumar
- Department of Mechanical Engineering, National University of Singapore, #05-26 Block EA, 9 Engineering Drive 1, Singapore, 117575, Singapore
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30
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Jungmann PM, Lange T, Wenning M, Baumann FA, Bamberg F, Jung M. Ankle Sprains in Athletes: Current Epidemiological, Clinical and Imaging Trends. Open Access J Sports Med 2023; 14:29-46. [PMID: 37252646 PMCID: PMC10216848 DOI: 10.2147/oajsm.s397634] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/06/2023] [Indexed: 05/31/2023] Open
Abstract
Purpose Ankle injuries are frequent sports injuries. Despite optimizing treatment strategies during recent years, the percentage of chronification following an ankle sprain remains high. The purpose of this review article is, to highlight current epidemiological, clinical and novel advanced cross-sectional imaging trends that may help to evaluate ankle sprain injuries. Methods Systematic PubMed literature research. Identification and review of studies (i) analyzing and describing ankle sprain and (ii) focusing on advanced cross-sectional imaging techniques at the ankle. Results The ankle is one of the most frequently injured body parts in sports. During the COVID-19 pandemic, there was a change in sporting behavior and sports injuries. Ankle sprains account for about 16-40% of the sports-related injuries. Novel cross-sectional imaging techniques, including Compressed Sensing MRI, 3D MRI, ankle MRI with traction or plantarflexion-supination, quantitative MRI, CT-like MRI, CT arthrography, weight-bearing cone beam CT, dual-energy CT, photon-counting CT, and projection-based metal artifact reduction CT may be introduced for detection and evaluation of specific pathologies after ankle injury. While simple ankle sprains are generally treated conservatively, unstable syndesmotic injuries may undergo stabilization using suture-button-fixation. Minced cartilage implantation is a novel cartilage repair technique for osteochondral defects at the ankle. Conclusion Applications and advantages of different cross-sectional imaging techniques at the ankle are highlighted. In a personalized approach, optimal imaging techniques may be chosen that best detect and delineate structural ankle injuries in athletes.
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Affiliation(s)
- Pia M Jungmann
- Department of Diagnostic and Interventional Radiology, Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Kantonsspital Graubünden, Chur, Switzerland
| | - Thomas Lange
- Department of Radiology, Medical Physics, Medical Center – University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Markus Wenning
- Department of Orthopedic and Trauma Surgery, Medical Center – University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Frédéric A Baumann
- Department of Vascular Medicine, Hospital of Schiers, Schiers, Switzerland
| | - Fabian Bamberg
- Department of Diagnostic and Interventional Radiology, Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Jung
- Department of Diagnostic and Interventional Radiology, Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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31
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Haskell MW, Nielsen JF, Noll DC. Off-resonance artifact correction for MRI: A review. NMR IN BIOMEDICINE 2023; 36:e4867. [PMID: 36326709 PMCID: PMC10284460 DOI: 10.1002/nbm.4867] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 09/25/2022] [Accepted: 11/01/2022] [Indexed: 06/06/2023]
Abstract
In magnetic resonance imaging (MRI), inhomogeneity in the main magnetic field used for imaging, referred to as off-resonance, can lead to image artifacts ranging from mild to severe depending on the application. Off-resonance artifacts, such as signal loss, geometric distortions, and blurring, can compromise the clinical and scientific utility of MR images. In this review, we describe sources of off-resonance in MRI, how off-resonance affects images, and strategies to prevent and correct for off-resonance. Given recent advances and the great potential of low-field and/or portable MRI, we also highlight the advantages and challenges of imaging at low field with respect to off-resonance.
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Affiliation(s)
- Melissa W Haskell
- Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, USA
- Hyperfine Research, Guilford, Connecticut, USA
| | | | - Douglas C Noll
- Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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32
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Waelti SL, Wildermuth S, Willems EP, Fischer T, Dietrich TJ, Leschka S, Matissek C, Krebs T, Markart S. Prospective Evaluation of Magnetic Resonance Imaging Features of Magnesium-Based Alloy Screw Resorption in Pediatric Fractures. J Clin Med 2023; 12:jcm12083016. [PMID: 37109351 PMCID: PMC10141748 DOI: 10.3390/jcm12083016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/17/2023] [Accepted: 04/19/2023] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND The resorption of magnesium-based alloy bioabsorbable screws results in the release of hydrogen gas, which can mimic infection and enter the growth plate. The screw itself and the released gas may also affect image quality. OBJECTIVE The evaluation of magnetic resonance imaging (MRI) findings during the most active phase of screw resorption is the objective, with particular focus on the growth plate and to assess for the presence of metal-induced artifacts. MATERIAL AND METHODS In total, 30 prospectively acquired MRIs from 17 pediatric patients with fractures treated with magnesium screws were assessed for the presence and distribution of intraosseous, extraosseous, and intra-articular gas; gas within the growth plate; osteolysis along the screw; joint effusion; bone marrow edema; periosteal reaction; soft tissue edema; and metal-induced artifacts. RESULTS Gas locules were found in the bone and soft tissues in 100% of the examinations, intra-articular in 40%, and in 37% of unfused growth plates. Osteolysis and the periosteal reaction were present in 87%, bone marrow edema in 100%, soft tissue edema in 100%, and joint effusion in 50% of examinations. Pile-up artifacts were present in 100%, and geometric distortion in 0% of examinations. Fat suppression was not significantly impaired in any examination. CONCLUSIONS Gas and edema in the bone and soft tissues are normal findings during the resorption of magnesium screws and should not be misinterpreted as infection. Gas can also be detected within growth plates. MRI examinations can be performed without metal artifact reduction sequences. Standard fat suppression techniques are not significantly affected.
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Affiliation(s)
- Stephan L Waelti
- Department of Radiology and Nuclear Medicine, Children's Hospital of Eastern Switzerland, 9006 St. Gallen, Switzerland
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland
| | - Simon Wildermuth
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland
| | - Erik P Willems
- Clinical Trials Unit, Biostatistics, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland
| | - Tim Fischer
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland
| | - Tobias J Dietrich
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland
| | - Sebastian Leschka
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland
| | - Christoph Matissek
- Department of Pediatric Surgery, Children's Hospital of Eastern Switzerland, 9006 St. Gallen, Switzerland
| | - Thomas Krebs
- Department of Pediatric Surgery, Children's Hospital of Eastern Switzerland, 9006 St. Gallen, Switzerland
| | - Stefan Markart
- Department of Radiology and Nuclear Medicine, Children's Hospital of Eastern Switzerland, 9006 St. Gallen, Switzerland
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland
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Winchester A, Kay-Rivest E, Bruno M, Hagiwara M, Moonis G, Jethanamest D. Image Quality and Artifact Reduction of a Cochlear Implant With Rotatable Magnets. Otol Neurotol 2023; 44:e223-e229. [PMID: 36806625 DOI: 10.1097/mao.0000000000003840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
OBJECTIVE To determine if metal reduction magnetic resonance imaging sequences and changes in implant placement minimize artifact from cochlear implants and improve visualization of intracranial structures. STUDY DESIGN Cadaveric study. SETTING Tertiary referral center. PATIENTS Five cadaveric heads. INTERVENTIONS Specimens were implanted with Advanced Bionics HiRes Ultra3D devices at nasion-external auditory canal angles of 90, 120, and 160 degrees, and distances from the external auditory canal of 9 or 12 cm. Standard brain/internal auditory canal (IAC) sequences with metal artifact reducing technique were acquired in a 1.5T scanner. MAIN OUTCOME MEASURES The primary outcome was visibility of 14 intracranial structures graded on a 4-point scale (1, structures <50% visible; 2, >50% visible with some areas nonvisible from artifact; 3, artifact present but adequate for diagnosis; and 4, high quality). Scores were determined by experienced head and neck radiologists and compared with one-way analysis of variance. RESULTS Imaging sequences included axial 5-mm whole-brain turbo spin echo (TSE) T2 with right to left and anterior to posterior encoding, fluid-attenuation inversion recovery high bandwidth, axial 5-mm whole-brain slice-encoding metal artifact correction (SEMAC), axial IAC constructive interference in steady state, and axial 3-mm T1 IAC with and without fat saturation. T1 IACs in axial and coronal planes were best for ipsilateral structures overall (mean [standard deviation {SD}], 3.8 [0.6] and 3.8 [0.5]). SEMAC (mean [SD], 3.5 [0.8]) was superior to TSE with anterior to posterior encoding (mean [SD], 3.5 [0.9) for ipsilateral cortex, cerebellopontine angle, and brainstem/cerebellum, and equivalent for the inner ear. Constructive interference in steady state and T1 with fat saturation were poor for all ipsilateral structures (mean, 2.8 [ p < 0.01]; mean, 3.1 [ p < 0.01]). The 120 degrees/12 cm position was overall best, although the 120 degrees/9 cm position still afforded visualization of ipsilateral structures; other angles and distances conferred slight advantages for specific structures of interest. CONCLUSIONS SEMAC and T2 TSE with anterior to posterior encoding sequences provide artifact suppression while retaining excellent image quality. Different placement angles did not confer improvement in visualization, although placement distances provided slight advantages for some structures.
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Affiliation(s)
| | | | - Mary Bruno
- Radiology, New York University Grossman School of Medicine, New York, New York
| | - Mari Hagiwara
- Radiology, New York University Grossman School of Medicine, New York, New York
| | - Gul Moonis
- Radiology, New York University Grossman School of Medicine, New York, New York
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Putra NE, Leeflang MA, Klimopoulou M, Dong J, Taheri P, Huan Z, Fratila-Apachitei LE, Mol JMC, Chang J, Zhou J, Zadpoor AA. Extrusion-based 3D printing of biodegradable, osteogenic, paramagnetic, and porous FeMn-akermanite bone substitutes. Acta Biomater 2023; 162:182-198. [PMID: 36972809 DOI: 10.1016/j.actbio.2023.03.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/13/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
The development of biodegradable Fe-based bone implants has rapidly progressed in recent years. Most of the challenges encountered in developing such implants have been tackled individually or in combination using additive manufacturing technologies. Yet not all the challenges have been overcome. Herein, we present porous FeMn-akermanite composite scaffolds fabricated by extrusion-based 3D printing to address the unmet clinical needs associated with Fe-based biomaterials for bone regeneration, including low biodegradation rate, MRI-incompatibility, mechanical properties, and limited bioactivity. In this research, we developed inks containing Fe, 35 wt% Mn, and 20 or 30 vol% akermanite powder mixtures. 3D printing was optimized together with the debinding and sintering steps to obtain scaffolds with interconnected porosity of 69%. The Fe-matrix in the composites contained the γ-FeMn phase as well as nesosilicate phases. The former made the composites paramagnetic and, thus, MRI-friendly. The in vitro biodegradation rates of the composites with 20 and 30 vol% akermanite were respectively 0.24 and 0.27 mm/y, falling within the ideal range of biodegradation rates for bone substitution. The yield strengths of the porous composites stayed within the range of the values of the trabecular bone, despite in vitro biodegradation for 28 d. All the composite scaffolds favored the adhesion, proliferation, and osteogenic differentiation of preosteoblasts, as revealed by Runx2 assay. Moreover, osteopontin was detected in the extracellular matrix of cells on the scaffolds. Altogether, these results demonstrate the remarkable potential of these composites in fulfilling the requirements of porous biodegradable bone substitutes, motivating future in vivo research. STATEMENT OF SIGNIFICANCE: We developed FeMn-akermanite composite scaffolds by taking advantage of the multi-material capacity of extrusion-based 3D printing. Our results demonstrated that the FeMn-akermanite scaffolds showed an exceptional performance in fulfilling all the requirements for bone substitution in vitro, i.e., a sufficient biodegradation rate, having mechanical properties in the range of trabecular bone even after 4 weeks biodegradation, paramagnetic, cytocompatible and most importantly osteogenic. Our results encourage further research on Fe-based bone implants in in vivo.
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Affiliation(s)
- N E Putra
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - M A Leeflang
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - M Klimopoulou
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - J Dong
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - P Taheri
- Department of Materials Science and Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - Z Huan
- Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, China.
| | - L E Fratila-Apachitei
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - J M C Mol
- Department of Materials Science and Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - J Chang
- Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, China.
| | - J Zhou
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - A A Zadpoor
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
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Manso Jimeno M, Vaughan JT, Geethanath S. Superconducting magnet designs and MRI accessibility: A review. NMR IN BIOMEDICINE 2023:e4921. [PMID: 36914280 DOI: 10.1002/nbm.4921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 02/13/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Presently, magnetic resonance imaging (MRI) magnets must deliver excellent magnetic field (B0 ) uniformity to achieve optimum image quality. Long magnets can satisfy the homogeneity requirements but require considerable superconducting material. These designs result in large, heavy, and costly systems that aggravate as field strength increases. Furthermore, the tight temperature tolerance of niobium titanium magnets adds instability to the system and requires operation at liquid helium temperature. These issues are crucial factors in the disparity of MR density and field strength use across the globe. Low-income settings show reduced access to MRI, especially to high field strengths. This article summarizes the proposed modifications to MRI superconducting magnet design and their impact on accessibility, including compact, reduced liquid helium, and specialty systems. Reducing the amount of superconductor inevitably entails shrinking the magnet size, resulting in higher field inhomogeneity. This work also reviews the state-of-the-art imaging and reconstruction methods to overcome this issue. Finally, we summarize the current and future challenges and opportunities in the design of accessible MRI.
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Affiliation(s)
- Marina Manso Jimeno
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, New York, USA
- Columbia Magnetic Resonance Research Center, Columbia University in the City of New York, New York, New York, USA
| | - John Thomas Vaughan
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, New York, USA
- Columbia Magnetic Resonance Research Center, Columbia University in the City of New York, New York, New York, USA
| | - Sairam Geethanath
- Columbia Magnetic Resonance Research Center, Columbia University in the City of New York, New York, New York, USA
- Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, The Biomedical Engineering and Imaging Institute, New York, New York, USA
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Berangi M, Kuehne A, Waiczies H, Niendorf T. MRI of Implantation Sites Using Parallel Transmission of an Optimized Radiofrequency Excitation Vector. Tomography 2023; 9:603-620. [PMID: 36961008 PMCID: PMC10037644 DOI: 10.3390/tomography9020049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/03/2023] [Accepted: 03/05/2023] [Indexed: 03/25/2023] Open
Abstract
Postoperative care of orthopedic implants is aided by imaging to assess the healing process and the implant status. MRI of implantation sites might be compromised by radiofrequency (RF) heating and RF transmission field (B1+) inhomogeneities induced by electrically conducting implants. This study examines the applicability of safe and B1+-distortion-free MRI of implantation sites using optimized parallel RF field transmission (pTx) based on a multi-objective genetic algorithm (GA). Electromagnetic field simulations were performed for eight eight-channel RF array configurations (f = 297.2 MHz), and the most efficient array was manufactured for phantom experiments at 7.0 T. Circular polarization (CP) and orthogonal projection (OP) algorithms were applied for benchmarking the GA-based shimming. B1+ mapping and MR thermometry and imaging were performed using phantoms mimicking muscle containing conductive implants. The local SAR10g of the entire phantom in GA was 12% and 43.8% less than the CP and OP, respectively. Experimental temperature mapping using the CP yielded ΔT = 2.5-3.0 K, whereas the GA induced no extra heating. GA-based shimming eliminated B1+ artefacts at implantation sites and enabled uniform gradient-echo MRI. To conclude, parallel RF transmission with GA-based excitation vectors provides a technical foundation en route to safe and B1+-distortion-free MRI of implantation sites.
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Affiliation(s)
- Mostafa Berangi
- Berlin Ultrahigh Field Facility, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
- Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
- MRI.TOOLS GmbH, 13125 Berlin, Germany
| | | | | | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
- Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
- MRI.TOOLS GmbH, 13125 Berlin, Germany
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Clinical evaluation of vertebral body replacement of carbon fiber-reinforced polyetheretherketone in patients with tumor manifestation of the thoracic and lumbar spine. Acta Neurochir (Wien) 2023; 165:897-904. [PMID: 36820888 PMCID: PMC10068665 DOI: 10.1007/s00701-023-05502-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 01/13/2023] [Indexed: 02/24/2023]
Abstract
PURPOSE Radiolucent anterior and posterior implants by carbon fiber-reinforced polyetheretherketone (CFR PEEK) aim to improve treatment of primary and secondary tumors of the spine during the last years. The aim of this study was to evaluate clinical and radiological outcomes after dorsoventral instrumentation using a CFR PEEK implant in a cohort of patients representing clinical reality. METHODS A total of 25 patients with tumor manifestation of the thoracic and lumbar spine underwent vertebral body replacement (VBR) using an expandable CFR PEEK implant between January 2021 and January 2022. Patient outcome, complications, and radiographic follow-up were analyzed. RESULTS A consecutive series aged 65.8 ± 14.7 (27.6-91.2) years were treated at 37 vertebrae of tumor manifestation, including two cases (8.0%) of primary tumor as well as 23 cases (92.0%) of spinal metastases. Overall, 26 cages covering a median of 1 level (1-4) were implanted. Duration of surgery was 134 ± 104 (65-576) min, with a blood loss of 792 ± 785 (100-4000) ml. No intraoperative cage revision was required. Surgical complications were reported in three (12.0%) cases including hemothorax in two cases (one intraoperative, one postoperative) and atrophic wound healing disorder in one case. In two cases (8.0%), revision surgery was performed (fracture of the adjacent tumorous vertebrae, progressive construct failure regarding cage subsidence). No implant failure was observed. CONCLUSION VBR using CFR PEEK cages represents a legitimate surgical strategy which opens a variety of improvements-especially in patients in need of postoperative radiotherapy of the spine and MRI-based follow-up examinations.
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Hirano M, Muto Y, Kuroda M, Fujiwara Y, Sasaki T, Kuroda K, Kamizaki R, Imajoh S, Tanabe Y, Al-Hammad WE, Nakamitsu Y, Shimizu Y, Sugimoto K, Oita M, Sugianto I, Bamgbose BO. Quantitative evaluation of the reduction of distortion and metallic artifacts in magnetic resonance images using the multiacquisition variable‑resonance image combination selective sequence. Exp Ther Med 2023; 25:109. [PMID: 36793326 PMCID: PMC9922940 DOI: 10.3892/etm.2023.11808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/04/2023] [Indexed: 01/26/2023] Open
Abstract
Magnetic resonance imaging (MRI) is superior to computed tomography (CT) in determining changes in tissue structure, such as those observed following inflammation and infection. However, when metal implants or other metal objects are present, MRI exhibits more distortion and artifacts compared with CT, which hinders the accurate measurement of the implants. A limited number of reports have examined whether the novel MRI sequence, multiacquisition variable-resonance image combination selective (MAVRIC SL), can accurately measure metal implants without distortion. Therefore, the present study aimed to demonstrate whether MAVRIC SL could accurately measure metal implants without distortion and whether the area around the metal implants could be well delineated without artifacts. An agar phantom containing a titanium alloy lumbar implant was used for the present study and was imaged using a 3.0 T MRI machine. A total of three imaging sequences, namely MAVRIC SL, CUBE and magnetic image compilation (MAGiC), were applied and the results were compared. Distortion was evaluated by measuring the screw diameter and distance between the screws multiple times in the phase and frequency directions by two different investigators. The artifact region around the implant was examined using a quantitative method following standardization of the phantom signal values. It was revealed that MAVRIC SL was a superior sequence compared with CUBE and MAGiC, as there was significantly less distortion, a lack of bias between the two different investigators and significantly reduced artifact regions. These results suggested the possibility of utilizing MAVRIC SL for follow-up to observe metal implant insertions.
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Affiliation(s)
- Masaki Hirano
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan,Department of Radiology, Osaka Red Cross Hospital, Osaka 543-8555, Japan
| | - Yuki Muto
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan,Department of Radiology, Oomoto Hospital, Okayama 700-0924, Japan
| | - Masahiro Kuroda
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan,Correspondence to: Professor Masahiro Kuroda, Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Yuta Fujiwara
- Division of Clinical Radiology Service, Okayama Central Hospital, Okayama 700-0017, Japan
| | - Tomoaki Sasaki
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan,Department of Diagnostic Radiology, National Cancer Center Hospital East, Chiba 277-8577, Japan
| | - Kazuhiro Kuroda
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan,Department of Health and Welfare Science, Graduate School of Health and Welfare Science, Okayama Prefectural University, Okayama 719-1197, Japan
| | - Ryo Kamizaki
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan
| | - Satoshi Imajoh
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan
| | - Yoshinori Tanabe
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan
| | - Wlla E. Al-Hammad
- Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-0017, Japan
| | - Yuki Nakamitsu
- Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan
| | - Yudai Shimizu
- Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-0017, Japan
| | - Kohei Sugimoto
- Graduate School of Interdisciplinary Sciences and Engineering in Health Systems, Okayama University, Okayama, 770-8558, Japan
| | - Masataka Oita
- Graduate School of Interdisciplinary Sciences and Engineering in Health Systems, Okayama University, Okayama, 770-8558, Japan
| | - Irfan Sugianto
- Department of Oral Radiology, Faculty of Dentistry, Hasanuddin University, Makassar, Sulawesi 90245, Indonesia
| | - Babatunde O. Bamgbose
- Department of Oral Diagnostic Sciences, Faculty of Dentistry, Bayero University, Kano 00234, Nigeria
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Engels-Domínguez N, Koops EA, Prokopiou PC, Van Egroo M, Schneider C, Riphagen JM, Singhal T, Jacobs HIL. State-of-the-art imaging of neuromodulatory subcortical systems in aging and Alzheimer's disease: Challenges and opportunities. Neurosci Biobehav Rev 2023; 144:104998. [PMID: 36526031 PMCID: PMC9805533 DOI: 10.1016/j.neubiorev.2022.104998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/30/2022] [Accepted: 11/07/2022] [Indexed: 12/14/2022]
Abstract
Primary prevention trials have shifted their focus to the earliest stages of Alzheimer's disease (AD). Autopsy data indicates that the neuromodulatory subcortical systems' (NSS) nuclei are specifically vulnerable to initial tau pathology, indicating that these nuclei hold great promise for early detection of AD in the context of the aging brain. The increasing availability of new imaging methods, ultra-high field scanners, new radioligands, and routine deep brain stimulation implants has led to a growing number of NSS neuroimaging studies on aging and neurodegeneration. Here, we review findings of current state-of-the-art imaging studies assessing the structure, function, and molecular changes of these nuclei during aging and AD. Furthermore, we identify the challenges associated with these imaging methods, important pathophysiologic gaps to fill for the AD NSS neuroimaging field, and provide future directions to improve our assessment, understanding, and clinical use of in vivo imaging of the NSS.
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Affiliation(s)
- Nina Engels-Domínguez
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, the Netherlands
| | - Elouise A Koops
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Prokopis C Prokopiou
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Maxime Van Egroo
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, the Netherlands
| | - Christoph Schneider
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Joost M Riphagen
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tarun Singhal
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Heidi I L Jacobs
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, the Netherlands.
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Vuorinen AM, Lehmonen L, Karvonen J, Holmström M, Kivistö S, Kaasalainen T. Reducing cardiac implantable electronic device-induced artefacts in cardiac magnetic resonance imaging. Eur Radiol 2023; 33:1229-1242. [PMID: 36029346 PMCID: PMC9889467 DOI: 10.1007/s00330-022-09059-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/17/2022] [Accepted: 07/24/2022] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Cardiac implantable electronic device (CIED)-induced metal artefacts possibly significantly diminish the diagnostic value of magnetic resonance imaging (MRI), particularly cardiac MR (CMR). Right-sided generator implantation, wideband late-gadolinium enhancement (LGE) technique and raising the ipsilateral arm to the generator during CMR scanning may reduce the CIED-induced image artefacts. We assessed the impact of generator location and the arm-raised imaging position on the CIED-induced artefacts in CMR. METHODS We included all clinically indicated CMRs performed on patients with normal cardiac anatomy and a permanent CIED with endocardial pacing leads between November 2011 and October 2019 in our institution (n = 171). We analysed cine and LGE sequences using the American Heart Association 17-segment model for the presence of artefacts. RESULTS Right-sided generator implantation and arm-raised imaging associated with a significantly increased number of artefact-free segments. In patients with a right-sided pacemaker, the median percentage of artefact-free segments in short-axis balanced steady-state free precession LGE was 93.8% (IQR 9.4%, n = 53) compared with 78.1% (IQR 20.3%, n = 58) for left-sided pacemaker (p < 0.001). In patients with a left-sided implantable cardioverter-defibrillator, the median percentage of artefact-free segments reached 87.5% (IQR 6.3%, n = 9) using arm-raised imaging, which fell to 62.5% (IQR 34.4%, n = 9) using arm-down imaging in spoiled gradient echo short-axis cine (p = 0.02). CONCLUSIONS Arm-raised imaging represents a straightforward method to reduce CMR artefacts in patients with left-sided generators and can be used alongside other image quality improvement methods. Right-sided generator implantation could be considered in CIED patients requiring subsequent CMR imaging to ensure sufficient image quality. KEY POINTS • Cardiac implantable electronic device (CIED)-induced metal artefacts may significantly diminish the diagnostic value of an MRI, particularly in cardiac MRIs. • Raising the ipsilateral arm relative to the CIED generator is a cost-free, straightforward method to significantly reduce CIED-induced artefacts on cardiac MRIs in patients with a left-sided generator. • Right-sided generator implantation reduces artefacts compared with left-sided implantation and could be considered in CIED patients requiring subsequent cardiac MRIs to ensure adequate image quality in the future.
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Affiliation(s)
- Aino-Maija Vuorinen
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Lauri Lehmonen
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Jarkko Karvonen
- Heart and Lung Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Miia Holmström
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Sari Kivistö
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Touko Kaasalainen
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
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Bieganowski T, Buchalter DB, Singh V, Mercuri JJ, Aggarwal VK, Rozell JC, Schwarzkopf R. Bone loss in aseptic revision total knee arthroplasty: management and outcomes. Knee Surg Relat Res 2022; 34:30. [PMID: 35725586 PMCID: PMC9208118 DOI: 10.1186/s43019-022-00158-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 05/21/2022] [Indexed: 12/04/2022] Open
Abstract
Background Although several techniques and implants have been developed to address bone loss in revision total knee arthroplasty (rTKA), management of these defects remains challenging. This review article discusses the indications and management options of bone loss following total knee arthroplasty based on preoperative workup and intraoperative findings. Main text Various imaging modalities are available that can be augmented with intraoperative examination to provide a clear classification of a bony defect. For this reason, the Anderson Orthopaedic Research Institute (AORI) classification is frequently used to guide treatment. The AORI provides a reliable system by which surgeons can classify lesions based on their size and involvement of surrounding structures. AORI type I defects are managed with cement with or without screws as well as impaction bone grafting. For AORI type IIA lesions, wedge or block augmentation is available. For large defects encompassing AORI type IIB and type III defects, bulk allografts, cones, sleeves, and megaprostheses can be used in conjunction with intramedullary stems. Conclusions Treatment of bone loss in rTKA continues to evolve as different techniques and approaches have been validated through short- and mid-term follow-up. Extensive preoperative planning with imaging, accurate intraoperative evaluation of the bone loss, and comprehensive understanding of all the implant options available for the bone loss are paramount to success.
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Oglesby RT, Lam WW, Ruschin M, Holden L, Sarfehnia A, Yeboah C, Sahgal A, Soliman H, Detsky J, Tseng CL, Myrehaug S, Husain Z, Lau AZ, Stanisz GJ, Chugh BP. Skull phantom-based methodology to validate MRI co-registration accuracy for Gamma Knife radiosurgery. Med Phys 2022; 49:7071-7084. [PMID: 35842918 DOI: 10.1002/mp.15851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/09/2022] [Accepted: 06/28/2022] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Target localization, for stereotactic radiosurgery (SRS) treatment with Gamma Knife, has become increasingly reliant on the co-registration between the planning MRI and the stereotactic cone-beam computed tomography (CBCT). Validating image registration between modalities would be particularly beneficial when considering the emergence of novel functional and metabolic MRI pulse sequences for target delineation. This study aimed to develop a phantom-based methodology to quantitatively compare the co-registration accuracy of the standard clinical imaging protocol to a representative MRI sequence that was likely to fail co-registration. The comparative methodology presented in this study may serve as a useful tool to evaluate the clinical translatability of novel MRI sequences. METHODS A realistic human skull phantom with fiducial marker columns was designed and manufactured to fit into a typical MRI head coil and the Gamma Knife patient positioning system. A series of "optimized" 3D MRI sequences-T1 -weighted Dixon, T1 -weighted fast field echo (FFE), and T2 -weighted fluid-attenuated inversion recovery (FLAIR)-were acquired and co-registered to the CBCT. The same sequences were "compromised" by reconstructing without geometric distortion correction and re-collecting with lower signal-to-noise-ratio (SNR) to simulate a novel MRI sequence with poor co-registration accuracy. Image similarity metrics-structural similarity (SSIM) index, mean squared error (MSE), and peak SNR (PSNR)-were used to quantitatively compare the co-registration of the optimized and compromised MR images. RESULTS The ground truth fiducial positions were compared to positions measured from each optimized image volume revealing a maximum median geometric uncertainty of 0.39 mm (LR), 0.92 mm (AP), and 0.13 mm (SI) between the CT and CBCT, 0.60 mm (LR), 0.36 mm (AP), and 0.07 mm (SI) between the CT and T1 -weighted Dixon, 0.42 mm (LR), 0.23 mm (AP), and 0.08 mm (SI) between the CT and T1 -weighted FFE, and 0.45 mm (LR), 0.19 mm (AP), and 1.04 mm (SI) between the CT and T2 -weighted FLAIR. Qualitatively, pairs of optimized and compromised image slices were compared using a fusion image where separable colors were used to differentiate between images. Quantitatively, MSE was the most predictive and SSIM the second most predictive metric for evaluating co-registration similarity. A clinically relevant threshold of MSE, SSIM, and/or PSNR may be defined beyond which point an MRI sequence should be rejected for target delineation based on its dissimilarity to an optimized sequence co-registration. All dissimilarity thresholds calculated using correlation coefficients with in-plane geometric uncertainty would need to be defined on a sequence-by-sequence basis and validated with patient data. CONCLUSION This study utilized a realistic skull phantom and image similarity metrics to develop a methodology capable of quantitatively assessing whether a modern research-based MRI sequence can be co-registered to the Gamma Knife CBCT with equal or less than equal accuracy when compared to a clinically accepted protocol.
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Affiliation(s)
- Ryan T Oglesby
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Wilfred W Lam
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Mark Ruschin
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Lori Holden
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Arman Sarfehnia
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.,Department of Physics, Ryerson University, Toronto, Ontario, Canada
| | - Collins Yeboah
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Arjun Sahgal
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Hany Soliman
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Jay Detsky
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Chia-Lin Tseng
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Sten Myrehaug
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Zain Husain
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Angus Z Lau
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Greg J Stanisz
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Neurosurgery and Paediatric Neurosurgery, Medical University of Lublin, Lublin, Poland.,Department of Physics, Ryerson University, Toronto, Ontario, Canada
| | - Brige P Chugh
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.,Department of Physics, Ryerson University, Toronto, Ontario, Canada
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43
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Postoperative MRI of the Ankle and Foot. Magn Reson Imaging Clin N Am 2022; 30:733-755. [DOI: 10.1016/j.mric.2022.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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44
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Cahill EM, Chee M, Kwong K. Assessing Radiology Practice Patterns for Obtaining MRI in Pediatric Patients with MR-Conditional Tracheostomy Tubes. EAR, NOSE & THROAT JOURNAL 2022:1455613221132388. [PMID: 36259239 DOI: 10.1177/01455613221132388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Silicone tracheostomy tubes are a popular choice for pediatric patients with chronic tracheostomies due to their pliability and increased comfort. However, the presence of wire reinforcement causes them to be labeled "MR-conditional." The objective of this study was to understand practice patterns across radiology departments for obtaining MRI in children with MR-conditional tracheostomy tubes. METHODS A survey consisting of 7 questions aimed at determining a facility's protocol for obtaining MRI in children with tracheostomy tubes was developed and administered via telephone to MRI technologists at US children's hospitals. RESULTS 182 children's hospitals were identified and 59 responses were obtained across 30 states (32.4%). 19 sites (32%) were excluded as they were unable to perform MRI. All 40 facilities reported that they have a standard questionnaire for medical implants, however only 20 reported that tracheostomy tubes are included on that questionnaire (50%). 6 (15%) reported all MR-conditional tubes are changed to MR-safe ones. Of the remaining 34, protocols were as follows: 1 (2.9%) scans patients with conditional tubes for a maximum of 15 minutes, 5 (14.7%) only use a 1.5T magnet, and 28 (82.3%) reported following the manufacturer conditions. In terms of artifact, 3 sites change MR-conditional tubes to MR-safe if scanning the head, neck, chest, or abdomen (8.8%), 6 (17.6%) change the tube if scanning the head or neck, 15 (44.1%) change the tube only if scanning the neck, and 10 (29.4%) were not aware of issues with artifact. CONCLUSION Based on this survey of MRI technologists at US children's hospitals, there is no unified protocol for obtaining MRI in pediatric patients with MR-conditional tracheostomy tubes. A lack of standardized protocols may be contributing to unnecessary tracheostomy changes. Future research includes clearly defining the anatomical regions affected by wire-related artifact and developing a standardized MRI protocol for these patients.
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Affiliation(s)
- Ellen M Cahill
- Rutgers Robert Wood Johnson Medical School(RWJMS), Piscataway, NJ, USA
| | - Michael Chee
- Division of Pediatric Otolaryngology, Joseph M. Sanzari Children's Hospital, Hackensack Meridian Children's Health, Hackensack, NJ, USA
| | - Kelvin Kwong
- Division of Pediatric Otolaryngology, Department of Otolaryngology - Head and Neck Surgery, Rutgers RWJMS, New Brunswick, NJ, USA
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State-of-the-art magnetic resonance imaging sequences for pediatric body imaging. Pediatr Radiol 2022:10.1007/s00247-022-05528-y. [PMID: 36255456 DOI: 10.1007/s00247-022-05528-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/17/2022] [Accepted: 10/03/2022] [Indexed: 10/24/2022]
Abstract
Longer examination time, need for anesthesia in smaller children and the inability of most children to hold their breath are major limitations of MRI in pediatric body imaging. Fortunately, with technical advances, many new and upcoming MRI sequences are overcoming these limitations. Advances in data acquisition and k-space sampling methods have enabled sequences with improved temporal and spatial resolution, and minimal artifacts. Sequences to minimize movement artifacts mainly utilize radial k-space filling, and examples include the stack-of-stars method for T1-weighted imaging and the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER)/BLADE method for T2-weighted imaging. Similarly, the sequences with improved temporal resolution and the ability to obtain multiple phases in a single breath-hold in dynamic imaging mainly use some form of partial k-space filling method. New sequences use a variable combination of data sampling methods like compressed sensing, golden-angle radial k-space filling, parallel imaging and partial k-space filling to achieve free-breathing, faster sequences that could be useful for pediatric abdominal and thoracic imaging. Simultaneous multi-slice method has improved diffusion-weighted imaging (DWI) with reduction in scan time and artifacts. In this review, we provide an overview of data sampling methods like parallel imaging, compressed sensing, radial k-space sampling, partial k-space sampling and simultaneous multi-slice. This is followed by newer available and upcoming sequences for T1-, T2- and DWI based on these other advances. We also discuss the Dixon method and newer approaches to reducing metal artifacts.
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46
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Thejeel B, Endo Y. Imaging of total hip arthroplasty: Part I – Implant design, imaging techniques, and imaging of component wear and fracture. Clin Imaging 2022; 98:74-85. [PMID: 36229386 DOI: 10.1016/j.clinimag.2022.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 09/14/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022]
Abstract
Despite being one of the most reliable procedures in orthopedic surgery, complications can occur after total hip arthroplasty, and radiology plays an essential role in their evaluation. This article will review the various types of hip arthroplasty and their normal appearances on imaging, followed by mechanisms and imaging appearances of component wear and fracture.
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Affiliation(s)
- Bashiar Thejeel
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Yoshimi Endo
- Department of Radiology and Imaging, Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA.
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Yau LK, Henry FU, Man Hong C, Amy C, Wai Kwan Vincent C, Ping Keung C, Kwong Yuen C. Swelling assessment after total knee arthroplasty. J Orthop Surg (Hong Kong) 2022; 30:10225536221127668. [PMID: 36122907 DOI: 10.1177/10225536221127668] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Total knee arthroplasty is a commonly performed elective orthopaedic surgery. Patients may endure substantial knee swelling following surgery, which are attributable to both effusion and edema. Studies have been aiming to identify an accurate and reliable method to quantify post-operative knee swelling to aid monitoring progress and treatment. The aim of this article was to review the means of clinically applicable measurements for knee swelling post TKA. METHODS The medical literature was searched using PubMed to search for articles published using the terms knee edema, effusion, swelling, knee arthroplasty, knee replacement, total knee arthroplasty, total knee replacement, TKA, TKR. Year of publication was not restricted. Only English language publications were included. Only full-text published articles from peer-reviewed journals were eligible for inclusion. The knee swelling measurement methods used in post TKA were reviewed. RESULTS Advancement in bioimpedance spectroscopy and handheld 3D scanning technology allows quick and precise quantification of knee swelling volume that the traditional clinical circumferential measurement and volumetric measurement lack. Handheld 3D scanning is also a potential tool to estimate the change of knee effusion volume and muscular volume after the surgery. Magnetic resonance imaging is accurate in effusion measurement but also the most time and resource demanding method. CONCLUSION Bioimpedance spectroscopy and 3D scanning technology can be the future tools for clinically measurement of knee swelling after total knee arthroplasty.
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Affiliation(s)
- Li Ka Yau
- Li Ka Shing Faculty of Medicine, 25809The University of Hong Kong, Hong Kong SAR, China
| | - F U Henry
- Division of Joint Replacement Surgery, Department of Orthopaedics and Traumatology, 25809The University of Hong Kong, Hong Kong SAR, China
| | - Cheung Man Hong
- Division of Joint Replacement Surgery, Department of Orthopaedics and Traumatology, 25809The University of Hong Kong, Hong Kong SAR, China
| | - Cheung Amy
- Division of Joint Replacement Surgery, Department of Orthopaedics and Traumatology, 26473Queen Mary Hospital, Hong Kong SAR, China
| | - Chan Wai Kwan Vincent
- Division of Joint Replacement Surgery, Department of Orthopaedics and Traumatology, 26473Queen Mary Hospital, Hong Kong SAR, China
| | - Chan Ping Keung
- Division of Joint Replacement Surgery, Department of Orthopaedics and Traumatology, 25809The University of Hong Kong, Hong Kong SAR, China
| | - Chiu Kwong Yuen
- Division of Joint Replacement Surgery, Department of Orthopaedics and Traumatology, 25809The University of Hong Kong, Hong Kong SAR, China
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Postoperative MR Imaging of the Elbow. Magn Reson Imaging Clin N Am 2022; 30:629-643. [DOI: 10.1016/j.mric.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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49
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Espiritu J, Berangi M, Yiannakou C, Silva E, Francischello R, Kuehne A, Niendorf T, Könneker S, Willumeit-Römer R, Seitz JM. Evaluating metallic artefact of biodegradable magnesium-based implants in magnetic resonance imaging. Bioact Mater 2022; 15:382-391. [PMID: 35386351 PMCID: PMC8958470 DOI: 10.1016/j.bioactmat.2021.11.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/12/2021] [Accepted: 11/28/2021] [Indexed: 11/13/2022] Open
Abstract
Magnesium (Mg) implants have shown to cause image artefacts or distortions in magnetic resonance imaging (MRI). Yet, there is a lack of information on how the degradation of Mg-based implants influences the image quality of MRI examinations. In this study, Mg-based implants are analysed in vitro, ex vivo, and in the clinical setting for various magnetic field strengths with the aim to quantify metallic artefact behaviour. In vitro corroded Mg-based screws and a titanium (Ti) equivalent were imaged according to the ASTM F2119. Mg-based and Ti pins were also implanted into rat femurs for different time points and scanned to provide insights on the influence of soft and hard tissue on metallic artefact. Additionally, MRI data of patients with scaphoid fractures treated with CE-approved Mg-based compression screws (MAGNEZIX®) were analysed at various time points post-surgery. The artefact production of the Mg-based material decreased as implant material degraded in all settings. The worst-case imaging scenario was determined to be when the imaging plane was selected to be perpendicular to the implant axis. Moreover, the Mg-based implant outperformed the Ti equivalent in all experiments by producing lower metallic artefact (p < 0.05). This investigation demonstrates that Mg-based implants generate significantly lower metallic distortion in MRI when compared to Ti. Our positive findings suggest and support further research into the application of Mg-based implants including post-operative care facilitated by MRI monitoring of degradation kinetics and bone/tissue healing processes. Mg-based implants produce lower metallic artefact than Ti in MRI. Metallic artefact production of Mg reduces as degradation increases. Mg implants provide sufficient visualisation in MRI for better postoperative care.
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Affiliation(s)
| | - Mostafa Berangi
- MRI.TOOLS GmbH, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany.,Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | | | - Eduarda Silva
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Roberto Francischello
- Chemistry and Industrial Chemistry Department, Università di Pisa, Via Moruzzi 13, Pisa, Italy.,Fondazione Toscana Gabriele Monasterio, Via Moruzzi 1, Pisa, Italy
| | | | - Thoralf Niendorf
- MRI.TOOLS GmbH, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany.,Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sören Könneker
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
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50
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Khodarahmi I, Brinkmann IM, Lin DJ, Bruno M, Johnson PM, Knoll F, Keerthivasan MB, Chandarana H, Fritz J. New-Generation Low-Field Magnetic Resonance Imaging of Hip Arthroplasty Implants Using Slice Encoding for Metal Artifact Correction: First In Vitro Experience at 0.55 T and Comparison With 1.5 T. Invest Radiol 2022; 57:517-526. [PMID: 35239614 PMCID: PMC9363001 DOI: 10.1097/rli.0000000000000866] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Despite significant progress, artifact-free visualization of the bone and soft tissues around hip arthroplasty implants remains an unmet clinical need. New-generation low-field magnetic resonance imaging (MRI) systems now include slice encoding for metal artifact correction (SEMAC), which may result in smaller metallic artifacts and better image quality than standard-of-care 1.5 T MRI. This study aims to assess the feasibility of SEMAC on a new-generation 0.55 T system, optimize the pulse protocol parameters, and compare the results with those of a standard-of-care 1.5 T MRI. MATERIALS AND METHODS Titanium (Ti) and cobalt-chromium total hip arthroplasty implants embedded in a tissue-mimicking American Society for Testing and Materials gel phantom were evaluated using turbo spin echo, view angle tilting (VAT), and combined VAT and SEMAC (VAT + SEMAC) pulse sequences. To refine an MRI protocol at 0.55 T, the type of metal artifact reduction techniques and the effect of various pulse sequence parameters on metal artifacts were assessed through qualitative ranking of the images by 3 expert readers while taking measured spatial resolution, signal-to-noise ratios, and acquisition times into consideration. Signal-to-noise ratio efficiency and artifact size of the optimized 0.55 T protocols were compared with the 1.5 T standard and compressed-sensing SEMAC sequences. RESULTS Overall, the VAT + SEMAC sequence with at least 6 SEMAC encoding steps for Ti and 9 for cobalt-chromium implants was ranked higher than other sequences for metal reduction ( P < 0.05). Additional SEMAC encoding partitions did not result in further metal artifact reductions. Permitting minimal residual artifacts, low magnetic susceptibility Ti constructs may be sufficiently imaged with optimized turbo spin echo sequences obviating the need for SEMAC. In cross-platform comparison, 0.55 T acquisitions using the optimized protocols are associated with 45% to 64% smaller artifacts than 1.5 T VAT + SEMAC and VAT + compressed-sensing/SEMAC protocols at the expense of a 17% to 28% reduction in signal-to-noise ratio efficiency. B 1 -related artifacts are invariably smaller at 0.55 T than 1.5 T; however, artifacts related to B 0 distortion, although frequently smaller, may appear as signal pileups at 0.55 T. CONCLUSIONS Our results suggest that new-generation low-field SEMAC MRI reduces metal artifacts around hip arthroplasty implants to better advantage than current 1.5 T MRI standard of care. While the appearance of B 0 -related artifacts changes, reduction in B 1 -related artifacts plays a major role in the overall benefit of 0.55 T.
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Affiliation(s)
- Iman Khodarahmi
- Department of Radiology, New York University Grossman School of Medicine
| | | | - Dana J. Lin
- Department of Radiology, New York University Grossman School of Medicine
| | - Mary Bruno
- Department of Radiology, New York University Grossman School of Medicine
| | | | - Florian Knoll
- Department of Radiology, New York University Grossman School of Medicine
| | | | - Hersh Chandarana
- Department of Radiology, New York University Grossman School of Medicine
| | - Jan Fritz
- Department of Radiology, New York University Grossman School of Medicine
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