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Boccalini S, Mayard C, Lacombe H, Villien M, Si-Mohamed S, Delahaye F, Boussel L, Budde RPJ, Pozzi M, Douek P. Ultra-High-Resolution and K-Edge Imaging of Prosthetic Heart Valves With Spectral Photon-Counting CT: A Phantom Study. Invest Radiol 2024; 59:589-598. [PMID: 38421666 DOI: 10.1097/rli.0000000000001068] [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: 03/02/2024]
Abstract
BACKGROUND AND PURPOSE The contribution of cardiac computed tomography (CT) for the detection and characterization of prosthetic heart valve (PHV) complications is still limited due mainly to artifacts. Computed tomography systems equipped with photon-counting detectors (PCDs) have the potential to overcome these limitations. Therefore, the aim of the study was to compare image quality of PHV with PCD-CT and dual-energy dual-layer CT (DEDL-CT). MATERIALS AND METHODS Two metallic and 3 biological PHVs were placed in a tube containing diluted iodinated contrast inside a thoracic phantom and scanned repeatedly at different angles on a DEDL-CT and PCD-CT. Two small lesions (~2 mm thickness; containing muscle and fat, respectively) were attached to the structure of 4 valves, placed inside the thoracic phantom, with and without an extension ring, and scanned again. Acquisition parameters were matched for the 2 CT systems and used for all scans. Metallic valves were scanned again with parameters adapted for tungsten K-edge imaging. For all valves, different metallic parts were measured on conventional images to assess their thickness and blooming artifacts. In addition, 6 parallelepipeds per metallic valve were drawn, and all voxels with density <3 times the standard deviation of the contrast media were recorded as an estimate of streak artifacts. For subjective analysis, 3 expert readers assessed conventional images of the valves, with and without lesions, and tungsten K-edge images. Conspicuity and sharpness of the different parts of the valve, the lesions, metallic, and blooming artifacts were scored on a 4-point scale. Measurements and scores were compared with the paired t test or Wilcoxon test. RESULTS The objective analysis showed that, with PCD-CT, valvular metallic structures were thinner and presented less blooming artifacts. Metallic artifacts were also reduced with PCD-CT (11 [interquartile (IQ) = 6] vs 40 [IQ = 13] % of voxels). Subjective analysis allowed noticing that some structures were visible or clearly visible only with PCD-CT. In addition, PCD-CT yielded better scores for the conspicuity and for the sharpness of all structures (all P s < 0.006), except for the conspicuity of the leaflets of the mechanical valves, which were well visible with either technique (4 [IQ = 3] for both). Both blooming and streak artifacts were reduced with PCD-CT ( P ≤ 0.01). Overall, the use of PCD-CT resulted in better conspicuity and sharpness of the lesions compared with DEDL-CT (both P s < 0.02). In addition, only with PCD-CT some differences between the 2 lesions were detectable. Adding the extension ring resulted in reduced conspicuity and sharpness with DEDL-CT ( P = 0.04 and P = 0.02, respectively) and only in reduced sharpness with PCD-CT ( P = 0.04). Tungsten K-edge imaging allowed for the visualization of the only dense structure containing it, the leaflets, and it resulted in images judged having less blooming and metallic artifacts as compared with conventional PCD-CT images ( P < 0.01). CONCLUSIONS With PCD-CT, objective and subjective image quality of metallic and biological PHVs is improved compared with DEDL-CT. Notwithstanding the improvements in image quality, millimetric lesions attached to the structure of the valves remain a challenge for PCD-CT. Tungsten K-edge imaging allows for even further reduction of artifacts.
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Affiliation(s)
- Sara Boccalini
- From the University of Lyon, INSA-Lyon, University Claude Bernard Lyon 1, Villeurbanne, France (S.B., F.D.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France (S.B., C.M., S.S.-M., L.B., P.D.); University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, Villeurbanne, France (H.L., S.S.-M., L.B., P.D.); Philips Healthcare, Suresnes, France (M.V.); Department of Cardiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France (F.D.); Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands (R.B.); and Department of Cardiac Surgery, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France (M.P.)
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Dube S, Pareek V, Barthwal M, Antony F, Sasaki D, Rivest R. Stereotactic Body Radiation Therapy (SBRT) in prostate cancer in the presence of hip prosthesis - is it a contraindication? A narrative review. BMC Urol 2024; 24:152. [PMID: 39061006 PMCID: PMC11282858 DOI: 10.1186/s12894-024-01479-8] [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: 11/05/2023] [Accepted: 04/06/2024] [Indexed: 07/28/2024] Open
Abstract
Hip replacement is a common orthopedic surgery in the aging population. With the rising incidence of prostate cancer, metallic hip prosthetics can cause considerable beam hardening and streak artifacts, leading to difficulty in identifying the target volumes and planning process for radiation treatment. The growing use of Stereotactic Body Radiation Therapy (SBRT) to treat prostate cancer is now well established. However, the use of this treatment modality in the presence of a hip prosthesis is poorly understood. There is enough literature on planning for external beam radiation treatment without any difficulties in the presence of hip prosthesis with conventional or Hypofractionated treatment. However, there is a shortage of literature on the impact of the prosthesis in SBRT planning, and there is a need for further understanding and measures to mitigate the obstacles in planning for SBRT in the presence of hip prosthesis. We present our review of the intricacies that need to be understood while considering SBRT in the presence of hip prostheses in prostate cancer treatment.
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Affiliation(s)
- Sheen Dube
- Department of Biochemistry, University of Winnipeg, Winnipeg, MB, Canada
| | - Vibhay Pareek
- Dept. of Radiation Oncology, CancerCare Manitoba, 675 McDermot Ave, Winnipeg, Winnipeg, MB, MB, R3E 0V9, Canada.
| | - Mansi Barthwal
- Dept. of Radiation Oncology, CancerCare Manitoba, 675 McDermot Ave, Winnipeg, Winnipeg, MB, MB, R3E 0V9, Canada
| | - Febin Antony
- Dept. of Radiation Oncology, CancerCare Manitoba, 675 McDermot Ave, Winnipeg, Winnipeg, MB, MB, R3E 0V9, Canada
| | - David Sasaki
- Department of Medical Physics, CancerCare Manitoba, Winnipeg, MB, Canada
| | - Ryan Rivest
- Department of Medical Physics, CancerCare Manitoba, Winnipeg, MB, Canada
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Shu G, Zhao L, Li F, Jiang Y, Zhang X, Yu C, Pan J, Sun SK. Metallic artifacts-free spectral computed tomography angiography based on renal clearable bismuth chelate. Biomaterials 2024; 305:122422. [PMID: 38128318 DOI: 10.1016/j.biomaterials.2023.122422] [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: 09/27/2023] [Revised: 11/28/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023]
Abstract
Computed tomography angiography (CTA) is one of the most important diagnosis techniques for various vascular diseases in clinic. However, metallic artifacts caused by metal implants and calcified plaques in more and more patients severely hinder its wide applications. Herein, we propose an improved metallic artifacts-free spectral CTA technique based on renal clearable bismuth chelate (Bi-DTPA dimeglumine) for the first time. Bi-DTPA dimeglumine owns the merits of ultra-simple synthetic process, approximately 100% of yield, large-scale production capability, good biocompatibility, and favorable renal clearable ability. More importantly, Bi-DTPA dimeglumine shows superior contrast-enhanced effect in CTA compared with clinical iohexol at a wide range of X-ray energies especially in higher X-ray energy. In rabbits' model with metallic transplants, Bi-DTPA dimeglumine assisted-spectral CTA can not only effectively mitigate metallic artifacts by reducing beam hardening effect under high X-ray energy, but also enables accurate delineation of vascular structure. Our proposed strategy opens a revolutionary way to solve the bottleneck problem of metallic artifacts in CTA examinations.
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Affiliation(s)
- Gang Shu
- School of Medical Imaging, Tianjin Medical University, Tianjin, 300203, China; Department of Radiology, The Second Hospital of Tianjin Medical University, Tianjin, 300211, China
| | - Lu Zhao
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Fengtan Li
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Yingjian Jiang
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Xuening Zhang
- Department of Radiology, The Second Hospital of Tianjin Medical University, Tianjin, 300211, China
| | - Chunshui Yu
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Jinbin Pan
- Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, China.
| | - Shao-Kai Sun
- School of Medical Imaging, Tianjin Medical University, Tianjin, 300203, China.
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Layer YC, Mesropyan N, Kupczyk PA, Luetkens JA, Isaak A, Dell T, Ernst BP, Attenberger UI, Kuetting D. Use of virtual monoenergetic images for reduction of extensive dental implant associated artifacts in photon-counting detector CT. Sci Rep 2024; 14:497. [PMID: 38177651 PMCID: PMC10766624 DOI: 10.1038/s41598-023-50926-3] [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: 04/05/2023] [Accepted: 12/28/2023] [Indexed: 01/06/2024] Open
Abstract
Aim of this study was to assess the impact of virtual monoenergetic images (VMI) on dental implant artifacts in photon-counting detector computed tomography (PCD-CT) compared to standard reconstructed polychromatic images (PI). 30 scans with extensive (≥ 5 dental implants) dental implant-associated artifacts were retrospectively analyzed. Scans were acquired during clinical routine on a PCD-CT. VMI were reconstructed for 100-190 keV (10 keV steps) and compared to PI. Artifact extent and assessment of adjacent soft tissue were rated using a 5-point Likert grading scale for qualitative assessment. Quantitative assessment was performed using ROIs in most pronounced hypodense and hyperdense artifacts, artifact-impaired soft tissue, artifact-free fat and muscle tissue. A corrected attenuation was calculated as difference between artifact-impaired tissue and tissue without artifacts. Qualitative assessment of soft palate and cheeks improved for all VMI compared to PI (Median PI: 1 (Range: 1-3) and 1 (1-3); e.g. VMI130 keV 2 (1-5); p < 0.0001 and 2 (1-4); p < 0.0001). In quantitative assessment, VMI130 keV showed best results with a corrected attenuation closest to 0 (PI: 30.48 ± 98.16; VMI130 keV: - 0.55 ± 73.38; p = 0.0026). Overall, photon-counting deducted VMI reduce the extent of dental implant-associated artifacts. VMI of 130 keV showed best results and are recommended to support head and neck CT scans.
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Affiliation(s)
- Yannik C Layer
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
| | - Narine Mesropyan
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Patrick A Kupczyk
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Julian A Luetkens
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Alexander Isaak
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Tatjana Dell
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Benjamin P Ernst
- Department of Otorhinolaryngology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Ulrike I Attenberger
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Daniel Kuetting
- Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
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Al-Haj Husain A, Oechslin DA, Stadlinger B, Winklhofer S, Özcan M, Schönegg D, Al-Haj Husain N, Sommer S, Piccirelli M, Valdec S. Preoperative imaging in third molar surgery - A prospective comparison of X-ray-based and radiation-free magnetic resonance orthopantomography. J Craniomaxillofac Surg 2024; 52:117-126. [PMID: 37891089 DOI: 10.1016/j.jcms.2023.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/31/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
This study aimed to compare preoperative data relevant to third molar surgery based on radiographic orthopantomography (OPG) and orthopantomogram-like MR images (MR-OPG), using five different MR protocols. X-ray-based OPG and OPG-like MRI reconstructions from DESS, SPACE-STIR, SPACE-SPAIR, T1-VIBE-Dixon, and UTE sequences were acquired in 11 patients undergoing third molar surgery, using a 15-channel mandibular coil. Qualitative (image quality, susceptibility to artifacts, positional relationship, contact/non-contact of the inferior alveolar nerve (IAN), relationship to maxillary sinus, IAN continuity, root morphology) and quantitative (tooth length, retromolar distance, distance to the IAN, and distance to the mandible margin) parameters of the maxillary and mandibular third molars were assessed regarding inter-reader agreement and quantitative discrepancies by three calibrated readers. Radiation-free MR-OPGs generated within clinically tolerable acquisition times, which exhibited high image quality and low susceptibility to artifacts, showed no significant differences compared with X-ray-based OPGs regarding the assessment of quantitative parameters. UTE MR-OPGs provided radiographic-like images and were best suited for assessing qualitative preoperative data (positional relationship, nerve contact/non-contact, and dental root morphology) relevant to third molar surgery. For continuous and focal nerve imaging, DESS MR-OPG was superior. MR-OPGs could represent a shift towards indication-specific and modality-oriented perioperative imaging in high-risk oral and maxillofacial surgery.
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Affiliation(s)
- Adib Al-Haj Husain
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Dominik A Oechslin
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Bernd Stadlinger
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Sebastian Winklhofer
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Mutlu Özcan
- Division of Dental Biomaterials, Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Clinic of Masticatory Disorders, Orofacial Pain Unit, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Daphne Schönegg
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Nadin Al-Haj Husain
- Division of Dental Biomaterials, Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Clinic of Masticatory Disorders, Orofacial Pain Unit, Center of Dental Medicine, University of Zurich, Zurich, Switzerland; Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Stefan Sommer
- Siemens Healthineers International AG, Zurich, Switzerland; Swiss Center for Musculoskeletal Imaging (SCMI), Balgrist Campus, Zurich, Switzerland; Advanced Clinical Imaging Technology (ACIT), Siemens Healthcare AG, Lausanne, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Silvio Valdec
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
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Hasegawa T, Arimoto S, Saito I, Yatagai N, Murakami A, Sasaki A, Tadokoro Y, Tani W, Kagawa K, Akashi M. Detection of bone marrow edema in differential diagnoses of odontogenic cysts using dual-energy computed tomography. Oral Maxillofac Surg 2023; 27:675-684. [PMID: 36121523 DOI: 10.1007/s10006-022-01113-7] [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: 11/02/2021] [Accepted: 09/13/2022] [Indexed: 10/14/2022]
Abstract
PURPOSE In this study, we prospectively investigated the relationship between bone marrow edema (BME) and odontogenic cysts and explored the possibility of using dual-energy computed tomography (DECT) as an auxiliary tool for the diagnosis of odontogenic cysts. METHODS This cross-sectional study included 73 patients who underwent the DECT scan and surgery for odontogenic cysts or odontogenic tumors. The virtual noncalcium (VNCa) computed tomography (CT) values and CT values were measured at several sites. The predictor variable was diagnosis, and the other variables included age, sex, and sites. The primary outcome was VNCa CT value. Variables were tested using the chi-square test or the Kruskal-Wallis test. The VNCa CT and CT values were tested using the Scheffe test for multiple comparisons. All variables were analyzed as independent variables affecting the VNCa CT values around the lesion in the multiple regression analysis. RESULT There were 35 men and 38 women. The mean patient age was 50.0 ± 19.5 years (range: 8-86). The VNCa CT values (- 6.2 ± 34.3) around the lesion in patients with RCs were significantly higher than those in patients with dentigerous cysts (- 44.4 ± 28.6) and odontogenic keratocysts (- 67.3 ± 19.5). In multiple regression analysis, the VNCa CT values around the lesion showed a significant positive correlation with histological results (regression coefficient: - 0.605, P < 0.001). CONCLUSION The presence of BME is associated with radicular cysts, and DECT can be used as an auxiliary tool for radicular cyst diagnosis.
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Affiliation(s)
- Takumi Hasegawa
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
| | - Satomi Arimoto
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Izumi Saito
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Nanae Yatagai
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Aki Murakami
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Aki Sasaki
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Yoshiaki Tadokoro
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Wakiko Tani
- Center for Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan
| | - Kiyosumi Kagawa
- Center for Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan
| | - Masaya Akashi
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
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Mazur-Hart DJ, Godil JA, Larson EW, Nugent JG, Gerges C, Pettersson DR, Ross DA. Evaluating Surgical Cervical Arthrodesis With a Novel MRI Grading Score. Clin Spine Surg 2023; 36:E493-E498. [PMID: 37448138 DOI: 10.1097/bsd.0000000000001487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023]
Abstract
STUDY DESIGN This was a single-institution retrospective study. OBJECTIVE Evaluate a magnetic resonance imaging (MRI)-scoring system to differentiate arthrodesis from pseudoarthrosis following anterior cervical discectomy and fusion. SUMMARY OF BACKGROUND DATA Diagnostic workup following fusion surgery often includes MRI to evaluate neural structures and computed tomography (CT) and/or dynamic x-rays to evaluate instrumentation and arthrodesis. The use of MRI alone for these evaluations would protect patients from harmful CT and x-ray ionizing radiation. METHODS Neurosurgical attending evaluated CTs for arthrodesis or pseudoarthrosis. Blinded neuroradiology attending and neurosurgery senior resident evaluated independent T1 and T2 region of interest (ROI) signal intensity over instrumented disk space. Cerebral spinal fluid (CSF) at the cisterna magnum and distal adjacent uninstrumented vertebral body (VB) were also calculated. ROI interspace /ROI CSF and ROI interspace /ROI VB quotients were used to create T1- and T2-interspace interbody scores (IIS). RESULTS Study population (n=64 patients, 50% female) with a mean age of 51.72 years and 109 instrumented levels with 45 fused levels (41.3%) were included. T1-weighted MRI, median T1-IIS CSF for arthrodesis was 176.20 versus 130.92 for pseudoarthrosis ( P <0.0001), T1-IIS VB for arthrodesis was 68.52 and pseudoarthrosis was 52.71 ( P <0.0001). T2-weighted MRI, median T2-IIS CSF for arthrodesis was 27.72 and 14.21 for pseudoarthrosis ( P <0.0001), while T2-IIS VB for arthrodesis was 67.90 and 41.02 for pseudoarthrosis ( P <0.0001). The greatest univariable discriminative capability for arthrodesis via AUROC was T1-IIS VB (0.7743). CONCLUSION We describe a novel MRI scoring system that may help determine arthrodesis versus pseudoarthrosis following anterior cervical discectomy and fusion. Postoperative symptomatic patients may only require MRI, which would protect patients from ionizing radiation. LEVEL OF EVIDENCE Level IV.
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Affiliation(s)
| | | | | | | | | | | | - Donald A Ross
- Department of Neurological Surgery
- Operative Care Division, Portland Veterans Affairs Medical Center, Portland, OR
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Al-Haj Husain A, Schmidt V, Valdec S, Stadlinger B, Winklhofer S, Schönegg D, Sommer S, Özcan M, Al-Haj Husain N, Piccirelli M. MR-orthopantomography in operative dentistry and oral and maxillofacial surgery: a proof of concept study. Sci Rep 2023; 13:6228. [PMID: 37069287 PMCID: PMC10110573 DOI: 10.1038/s41598-023-33483-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/13/2023] [Indexed: 04/19/2023] Open
Abstract
This prospective study aimed to present, compare, and evaluate the suitability of five different magnetic resonance imaging (MRI) protocols (3D double-echo steady-state (DESS), 3D fast spin echo short-tau inversion recovery (SPACE-STIR), 3D fast spin echo spectral attenuated inversion recovery (SPACE-SPAIR), volumetric interpolated breath-hold examination (T1-VIBE-Dixon), and ultrashort echo time (UTE)) and for orthopantomogram (OPG)-like MRI reconstructions using a novel mandibular coil. Three readers assessed MR-OPGs of 21 volunteers regarding technical image quality (4, excellent; 0, severely reduced), susceptibility to artifacts (3, absence; 0, massive), and visualization of anatomical structures in the oral cavity and surrounding skeletal structures (4, fine details visible; 0, no structures visible). Average image quality was good (3.29 ± 0.83) for all MRI protocols, with UTE providing the best image quality (3.52 ± 0.62) and no to minor artifacts (2.56 ± 0.6). Full diagnostic interpretability of the osseous structures is best in VIBE-Dixon and UTE MR-OPGs. DESS provided excellent visualization of the finest details of the nervous tissue (3.95 ± 0.22). Intra-reader and inter-reader agreement between the readers was good to excellent for all protocols (ICCs 0.812-0.957). MR-OPGs provide indication-specific accurate imaging of the oral cavity and could contribute to the early detection of pathologies, staging, and radiological follow-up of oral and maxillofacial diseases.
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Affiliation(s)
- Adib Al-Haj Husain
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, CH-8032, Zurich, Switzerland.
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Valérie Schmidt
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, CH-8032, Zurich, Switzerland
| | - Silvio Valdec
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, CH-8032, Zurich, Switzerland
| | - Bernd Stadlinger
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, CH-8032, Zurich, Switzerland
| | - Sebastian Winklhofer
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Daphne Schönegg
- Departement of Cranio-Maxillo-Facial and Oral Surgery, University Hospital Zurich, Zurich, Switzerland
| | - Stefan Sommer
- Siemens Healthineers International AG, Zurich, Switzerland
- Swiss Center for Musculoskeletal Imaging (SCMI), Balgrist Campus, Zurich, Switzerland
- Advanced Clinical Imaging Technology (ACIT), Siemens Healthcare AG, Lausanne, Switzerland
| | - Mutlu Özcan
- Division of Dental Biomaterials, Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Nadin Al-Haj Husain
- Division of Dental Biomaterials, Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
- Departement of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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Mellander H, Bengtsson P, Fransson V, Ramgren B, Undrén P, Drake M, Ydström K, Lätt J, Hilal A, Wassélius J, Ullberg T. Virtual monoenergetic images by spectral detector computed tomography may improve image quality and diagnostic ability for ischemic lesions in acute ischemic stroke. Acta Radiol 2023; 64:1631-1640. [PMID: 36255120 PMCID: PMC10588276 DOI: 10.1177/02841851221130612] [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: 12/16/2021] [Accepted: 09/08/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND Acute ischemic lesions are challenging to detect by conventional computed tomography (CT). Virtual monoenergetic images may improve detection rates by increased tissue contrast. PURPOSE To compare the ability to detect ischemic lesions of virtual monoenergetic with conventional images in patients with acute stroke. MATERIAL AND METHODS We included consecutive patients at our center that underwent brain CT in a spectral scanner for suspicion of acute stroke, onset <12 h, with or without (negative controls) a confirmed cortical ischemic lesion in the initial scan or a follow-up CT or magnetic resonance imaging. Attenuation was measured in predefined areas in ischemic gray (guided by follow-up exams), normal gray, and white matter in conventional images and retrieved in spectral diagrams for the same locations in monoenergetic series at 40-200 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Visual assessment of diagnostic measures was performed by independent review by two neuroradiologists blinded to reconstruction details. RESULTS In total, 29 patients were included (January 2018 to July 2019). SNR was higher in virtual monoenergetic compared to conventional images, significantly at 60-150 keV. CNR between ischemic gray and normal white matter was higher in monoenergetic images at 40-70 keV compared to conventional images. Virtual monoenergetic images received higher scores in overall image quality. The sensitivity for diagnosing acute ischemia was 93% and 97%, respectively, for the reviewers, compared to 55% of the original report based on conventional images. CONCLUSION Virtual monoenergetic reconstructions of spectral CIs may improve image quality and diagnostic ability in stroke assessment.
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Affiliation(s)
- Helena Mellander
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Pär Bengtsson
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Veronica Fransson
- Department of Translational Medicine, Medical Radiation Physics, Lund University, Malmö, Sweden
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Birgitta Ramgren
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Per Undrén
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Mattias Drake
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Kristina Ydström
- Department of Clinical Sciences, Lund University, Lund, Sweden
- Department of Translational Medicine, Medical Radiation Physics, Lund University, Malmö, Sweden
| | - Jimmy Lätt
- Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - Amir Hilal
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Johan Wassélius
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Teresa Ullberg
- Department of Neuroradiology and Odontology, Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
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Metal artifact reduction by virtual monoenergetic reconstructions from spectral brain CT. Eur J Radiol Open 2023; 10:100479. [PMID: 36819113 PMCID: PMC9932346 DOI: 10.1016/j.ejro.2023.100479] [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: 01/28/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023] Open
Abstract
Purpose Conventional computed tomography (CT) images are severely affected by metal artifacts in patients with intracranial coils. Monoenergetic images have been suggested to reduce metal artifacts.The aim of this study was to assess metal artifacts in virtual monoenergetic images (VMIs) reconstructed from spectral brain CT. Methods Thirty-two consecutive patients with intracranial coils examined by spectral non contrast brain CT (NCCT) at our center between November 2017 and April 2019 were included. Attenuation and standard deviations were measured in regions of interest (ROIs) at predefined areas in artifact-free and artifact-affected areas. Measurements were performed in conventional polyenergetic images (CIs) and the corresponding data for VMIs were retrieved through spectral diagrams for the each ROI. Subjective analysis was performed by visual grading of CIs and specific VMIs by two neuroradiologists, independently. Results In artefact-affected image areas distal from the metal objects, the attenuation values decreased with higher energy level VMIs. The same effect was not seen for artefact-affected image areas close to the metal.Subjective rating of the artefact severity was significantly better in VMIs at 50 keV for one of the two reviewers compared to the CIs. Overall image quality and tissue differentiation scores were significantly higher for both reviewers in VMIs at 60 and 70 keV compared to CIs. Conclusion Our quantitative and qualitative image analysis shown that there is a small significant reduction of intracranial coils artifacts severity by all monoenergetic reconstructions from 50 to 200 keV with preserved or increased overall subjective image quality compared to conventional images.
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Key Words
- Aneurysm
- CIs, conventional images
- CSF, cerebrospinal fluid
- CT, computed tomography
- DECT, dual energy computed tomography
- DLP, dose length product
- DSA, digital subtraction angiography
- Diagnostic imaging
- HU, Hounsfield units
- IQR, interquartile range
- MRI, magnetic resonance imaging
- Metal artifacts
- Monoenergetic imaging
- PACS, Picture Archiving and Communication System
- ROI, region of interest
- SD, standard deviation
- SNR, signal-to-noise ratio
- VMIs, virtual monoenergetic images
- WM, white matter
- X-ray computed tomography
- keV, kiloelectron volt
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11
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Al-Haj Husain A, Stadlinger B, Özcan M, Schönegg D, Winklhofer S, Al-Haj Husain N, Piccirelli M, Valdec S. Buccal bone thickness assessment for immediate anterior dental implant planning: A pilot study comparing cone-beam computed tomography and 3D double-echo steady-state MRI. Clin Implant Dent Relat Res 2023; 25:35-45. [PMID: 36454235 DOI: 10.1111/cid.13160] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 10/16/2022] [Accepted: 10/17/2022] [Indexed: 12/03/2022]
Abstract
PURPOSE To evaluate image quality and diagnostic accuracy of buccal bone thickness assessment in maxillary and mandibular anterior region using cone-beam computed tomography (CBCT) and 3-dimensional double-echo steady-state (DESS) MRI for preoperative planning of immediate dental implants in healthy individuals. METHODS One hundred and twenty teeth in 10 volunteers were retrospectively evaluated for image quality and artifacts using Likert scale (4 = excellent to 0 = decreased). Buccal bone thickness was measured at three measurement points (M1 = 2 mm from the cementoenamel junction, M2 = middle of the root, and M3 = at the root apex) for each tooth in the maxillary (13-23) and the mandibular anterior region (33-43). Descriptive statistics and two-way ANOVA with Tukey's Post-hoc test were performed to evaluate the significant differences (α = 0.05) between both imaging modalities. RESULTS Image quality showed little to no artifacts and enabled confident diagnostic interpretation (CBCT (3.72 ± 0.46); MRI (3.65 ± 0.49)), with no significant differences between both imaging modalities (p > 0.05). Regarding the assessment of buccal bone thickness at M1-M3 for the teeth 13-23 and 33-43, no significant differences were noted (p > 0.05). MRI demonstrated slight, nonsignificant overestimation of thickness with the canines having mainly a thick buccal bone wall, where thin buccal wall was evident for the central incisors. CONCLUSION Black bone MRI sequences, such as 3D-DESS MRI, for immediate implant planning provided confidential diagnostic accuracy in bone thickness assessment without significant disadvantages compared to CBCT. Thus, the implementation of no-dose protocols for dental rehabilitation using an immediate loading approach seems promising and could further improve the treatment strategy for dental rehabilitation.
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Affiliation(s)
- Adib Al-Haj Husain
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Bernd Stadlinger
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Mutlu Özcan
- Division of Dental Biomaterials, Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Daphne Schönegg
- Department of Cranio-Maxillo-Facial and Oral Surgery, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
| | - Sebastian Winklhofer
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Nadin Al-Haj Husain
- Division of Dental Biomaterials, Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.,Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Silvio Valdec
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
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12
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Metal implants on abdominal CT: does split-filter dual-energy CT provide additional value over iterative metal artifact reduction? Abdom Radiol (NY) 2023; 48:424-435. [PMID: 36180598 PMCID: PMC9849167 DOI: 10.1007/s00261-022-03682-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 09/09/2022] [Accepted: 09/09/2022] [Indexed: 01/27/2023]
Abstract
PURPOSE To assess image quality and metal artifact reduction in split-filter dual-energy CT (sfDECT) of the abdomen with hip or spinal implants using virtual monoenergetic images (VMI) and iterative metal artifact reduction algorithm (iMAR). METHODS 102 portal-venous abdominal sfDECTs of patients with hip (n = 71) or spinal implants (n = 31) were included in this study. Images were reconstructed as 120kVp-equivalent images (Mixed) and VMI (40-190 keV), with and without iMAR. Quantitative artifact and image noise was measured using 12 different ROIs. Subjective image quality was rated by two readers using a five-point Likert-scale in six categories, including overall image quality and vascular contrast. RESULTS Lowest quantitative artifact in both hip and spinal implants was measured in VMI190keV-iMAR. However, it was not significantly lower than in MixediMAR (for all ROIs, p = 1.00), which were rated best for overall image quality (hip: 1.00 [IQR: 1.00-2.00], spine: 3.00 [IQR:2.00-3.00]). VMI50keV-iMAR was rated best for vascular contrast (hip: 1.00 [IQR: 1.00-2.00], spine: 2.00 [IQR: 1.00-2.00]), which was significantly better than Mixed (both, p < 0.001). VMI50keV-iMAR provided superior overall image quality compared to Mixed for hip (1.00 vs 2.00, p < 0.001) and similar diagnostic image quality for spinal implants (2.00 vs 2.00, p = 0.51). CONCLUSION For abdominal sfDECT with hip or spinal implants MixediMAR images should be used. High keV VMI do not further improve image quality. IMAR allows the use of low keV images (VMI50keV) to improve vascular contrast, compared to Mixed images.
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13
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The Impact of Virtual Monoenergetic Imaging on Visualization of the Cervical Spinal Canal. J Comput Assist Tomogr 2023; 47:160-164. [PMID: 36112014 DOI: 10.1097/rct.0000000000001383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
RATIONALE AND OBJECTIVES Our purpose is to explore the role of dual-energy computed tomography (DECT) and virtual monoenergetic energy levels in reducing shoulder artifact to improve visualization of the cervical spinal canal. MATERIALS AND METHODS A retrospective review of 171 consecutive DECT scans of the neck (95 male, 65 female; mean age, 60.9 years, ranging from 18 to 88 years; with 11 excluded because of nondiagnostic image quality) during an 8-month period was performed with postprocessing of monoenergetic images at 50, 70, 100, and 140 keV. Subjective comparisons and objective image noise between the monoenergetic images and standard computed tomography (CT) were analyzed by 1-way analysis of variance to determine the optimal DECT energy level with the highest image quality. RESULTS Subjectively, 100-keV DECT best visualizes the spinal canal relative to standard CT, 50 and 70 keV ( P < 0.01), and was superior to 140 keV for reader 1 ( P < 0.01). Objectively, 100 keV demonstrated less noise relative to 50 keV (72.02; P < 0.01). There was no difference in noise between 100 keV and 70 keV, or between 100 keV and standard CT, which also demonstrated lower noise relative to 50-, 70-, and 140-keV levels (91.53, P < 0.01; 29.84, P < 0.01; and 22.66, P < 0.03). CONCLUSION Dual-energy CT at 100 keV may be the preferred DECT monoenergetic level for soft tissue assessment. Increasing energy level is associated with reduction in shoulder artifact, with no difference in noise between 100 keV and standard CT, although 100-keV images may be subjectively better.
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14
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Schlaeger S, Kirschke JS. Postoperative Bildgebung der Wirbelsäule. DIE RADIOLOGIE 2022; 62:851-861. [PMID: 35789426 PMCID: PMC9519694 DOI: 10.1007/s00117-022-01034-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 05/31/2022] [Indexed: 11/29/2022]
Abstract
Die Bildgebung der postoperativen Wirbelsäule hat im Wesentlichen zwei Aufgaben: Sie dient der Kontrolle des operativen Erfolgs und der Identifikation von Komplikationen. Dafür stehen die konventionelle Röntgenaufnahme, Computertomographie (CT), Myelographie und Magnetresonanztomographie (MRT) zur Verfügung. Unter Berücksichtigung der präoperativen Situation, der durchgeführten Operation und der postoperativen Beschwerdekonstellation ist es Aufgabe der Radiologinnen und Radiologen, die passende Modalität für eine suffiziente Diagnostik zu wählen. Insbesondere der Zustand nach Implantation von Fremdmaterial bedeutet eine technische Herausforderung im Rahmen der Bildakquisition. In der Befundung sehen sich die Radiologinnen und Radiologen mit der Aufgabe konfrontiert, zwischen natürlichen, zu erwartenden postoperativen Veränderungen und relevanten Komplikationen zu differenzieren. Ein reger Austausch mit Patientinnen und Patienten und zuweisenden Klinikerinnen und Klinikern ist dabei unerlässlich. Insbesondere klinische Hinweise auf einen Infekt, neue oder deutliche progrediente neurologische Ausfallserscheinungen und das Konus-Kauda-Syndrom erfordern eine zeitnahe Diagnosestellung, um eine rasche Therapieeinleitung zu gewährleisten.
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Affiliation(s)
- S Schlaeger
- Abteilung für Diagnostische und Interventionelle Neuroradiologie, Klinikum rechts der Isar, Ismaninger Str. 22, 81675, München, Deutschland.
| | - J S Kirschke
- Abteilung für Diagnostische und Interventionelle Neuroradiologie, Klinikum rechts der Isar, Ismaninger Str. 22, 81675, München, Deutschland.
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15
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Witkam RL, Buckens CF, van Goethem JWM, Vissers KCP, Henssen DJHA. The current role and future directions of imaging in failed back surgery syndrome patients: an educational review. Insights Imaging 2022; 13:117. [PMID: 35838802 PMCID: PMC9287525 DOI: 10.1186/s13244-022-01246-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 06/02/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Failed back surgery syndrome (FBSS) is an umbrella term referring to painful sensations experienced by patients after spinal surgery, mostly of neuropathic nature. Adequate treatment of FBSS is challenging, as its etiology is believed to be multifactorial and still not fully clarified. Accurate identification of the source of pain is difficult but pivotal to establish the most appropriate treatment strategy. Although the clinical utility of imaging in FBSS patients is still contentious, objective parameters are highly warranted to map different phenotypes of FBSS and tailor each subsequent therapy. MAIN BODY Since technological developments have weakened the applicability of prior research, this educational review outlined the recent evidence (i.e., from January 2005 onwards) after a systematic literature search. The state of the art on multiple imaging modalities in FBSS patients was reviewed. Future directions related to functional MRI and the development of imaging biomarkers have also been discussed. CONCLUSION Besides the fact that more imaging studies correlated with symptomatology in the postoperative setting are warranted, the current educational review outlined that contrast-enhanced MRI and MR neurography have been suggested as valuable imaging protocols to assess alterations in the spine of FBSS patients. The use of imaging biomarkers to study correlations between imaging features and symptomatology might hold future potential; however, more research is required before any promising hypotheses can be drawn.
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Affiliation(s)
- Richard L Witkam
- Department of Anaesthesiology, Pain and Palliative Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands. .,Department of Neurosurgery, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Constantinus F Buckens
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Johan W M van Goethem
- Department of Medical and Molecular Imaging, General Hospital Nikolaas, Sint-Niklaas, Belgium
| | - Kris C P Vissers
- Department of Anaesthesiology, Pain and Palliative Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Dylan J H A Henssen
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
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16
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Lacroix M, Ferrero E, Burns R, Guigui P, Clement O, Feydy A. Lumbar Spine Posttherapeutic Imaging. Semin Musculoskelet Radiol 2022; 26:314-328. [PMID: 35654097 DOI: 10.1055/s-0041-1740381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Management of patients after lumbar spine surgery or interventional radiology can be complex, and postoperative imaging patterns are often poorly understood by nonspecialized radiologists. This article focuses on postoperative imaging features of the lumbar spine in five clinical settings (with corresponding interventions): vertebral osteoporotic fractures (percutaneous vertebroplasty and vertebral augmentation), lumbar disk herniation (surgical diskectomy and percutaneous interventional radiology), lumbar spinal stenosis (surgical decompression), lumbar spondylolisthesis (surgical decompression and fusion), and degenerative scoliosis (techniques of osteotomies).For each intervention, we discuss imaging indications, depending if the patient is asymptomatic or if there are suspected complications, describe normal and pathologic imaging features, and present key points.
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Affiliation(s)
- Maxime Lacroix
- Department of Musculoskeletal Radiology, Hôpital Cochin, AP-HP Centre, Université de Paris, Paris, France.,Department of Radiology, Hôpital Européen Georges-Pompidou, AP-HP Centre, Université de Paris, Paris, France
| | - Emmanuelle Ferrero
- Department of Orthopaedic Surgery, Hôpital Européen Georges-Pompidou, AP-HP Centre, Université de Paris, Paris, France
| | - Robert Burns
- Department of Musculoskeletal Radiology, Hôpital Cochin, AP-HP Centre, Université de Paris, Paris, France
| | - Pierre Guigui
- Department of Orthopaedic Surgery, Hôpital Européen Georges-Pompidou, AP-HP Centre, Université de Paris, Paris, France
| | - Olivier Clement
- Department of Radiology, Hôpital Européen Georges-Pompidou, AP-HP Centre, Université de Paris, Paris, France
| | - Antoine Feydy
- Department of Musculoskeletal Radiology, Hôpital Cochin, AP-HP Centre, Université de Paris, Paris, France
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17
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Mohammadinejad P, Khandelwal A, Inoue A, Takahashi H, Yalon M, Long Z, Halaweish AF, Leng S, Yu L, Lee YS, McCollough CH, Fletcher JG. Utility of an automatic adaptive iterative metal artifact reduction AiMAR algorithm in improving CT imaging of patients with hip prostheses evaluated for suspected bladder malignancy. Abdom Radiol (NY) 2022; 47:2158-2167. [PMID: 35320381 DOI: 10.1007/s00261-022-03475-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare the utility of a novel metal artifact reduction algorithm to standard imaging in improving visualization of key structures, diagnostic confidence, and patient-level confidence in malignancy in patients with suspected bladder cancer. METHODS Patients with hip implants undergoing CT urography for suspected bladder malignancy were enrolled. Images were reconstructed using 3 methods: (1) Filtered Back Projection (FBP), (2) Iterative Metal Artifact Reduction (iMAR), and (3) Adaptive Iterative Metal Artifact Reduction (AiMAR) strength 4. In multiple reading sessions, three radiologists graded visualization of critical anatomic structures and artifact severity (6-point scales, lower scores desirable), and diagnostic confidence in blinded fashion. They also graded patient-level confidence in malignancy based on imaging findings in each patient. RESULTS Thirty-two patients (8 females) with a mean age of 74.5 ± 8.5 years were included. The median (range) visualization scores for FBP, iMAR, and AiMAR were 3.6 (1.1-4.9), 1.6 (0.3-2.8), and 1.6 (0.3-2.6), respectively. Both iMAR and AiMAR had anatomic visualization and artifact scores better than FBP (P < 0.001 for both) and similar to each other (P > 0.05). Structures with the most improvement in visualization score with the use of metal artifact reduction algorithms included the obturator internus muscle, internal and external iliac nodal chains, and vagina. iMAR and AiMAR improved diagnostic confidence (P < 0.001) and patient-level confidence in malignancy (P ≤ 0.24). CONCLUSION For patients with hip prostheses and suspected bladder malignancy, the use of iMAR or AiMAR was shown to significantly reduce metal artifacts, thus improving diagnostic confidence and patient-level confidence in malignancy.
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Affiliation(s)
- Payam Mohammadinejad
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Ashish Khandelwal
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Akitoshi Inoue
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Hiroaki Takahashi
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Mariana Yalon
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Zaiyang Long
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Ahmed F Halaweish
- Siemens Medical Solutions USA, 40 Liberty Boulevard, Malvern, PA, 19355, USA
| | - Shuai Leng
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Yong S Lee
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Cynthia H McCollough
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Joel G Fletcher
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
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Foti G, Lombardo F, Guerriero M, Rodella T, Cicciò C, Faccioli N, Serra G, Manenti G. Management of vertebral compression fractures: the role of dual-energy CT in clinical practice. Radiol Med 2022; 127:627-636. [PMID: 35553350 DOI: 10.1007/s11547-022-01498-1] [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: 10/28/2021] [Accepted: 04/20/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the role of dual-energy computed tomography (DECT) in the management of vertebral compression fractures in clinical practice. MATERIALS AND METHODS This retrospective IRB-approved study included 497 consecutive patients with suspected acute vertebral fractures, imaged either by DECT (group 1) or MRI (group 2) before vertebroplasty. The site, number and type of fractures at imaging findings, and clinical outcome based on any change in pain (DELTA-VAS), before (VAS-pre) and after treatment (VAS-post), were determined and compared. Two radiologists evaluated DECT and MRI images (15 and 5 years of experience, respectively), and inter-observer and intra-observer agreement were calculated using k statistics. RESULTS Both in the control group (n = 124) and in the group of patients treated by vertebroplasty (n = 373), the clinical outcome was not influenced by the imaging approach adopted, with a DELTA-VAS of 5.45 and 6.42 in the DECT group and 5.12 and 6.65 in the MRI group (p = 0.326; p = 0.44). In the group of treated patients, sex, age, lumbar fractures, multiple fractures, previous fractures, Genant grade, involvement of anterior apex or superior endplates, and increased spinal curvatures were similar (p = ns); however, dorsal fractures were more prevalent in group 1 (p = 0.0197). Before treatment, the mean VAS-pre was 8.74 in group 1 (DECT) and 8.65 in group 2 (MRI) (p = 0.301), whereas after treatment, the mean VAS-post value was 2.32 in group 1 (p = 0.0001), and 2.00 in group 2 (p = 0.0001). The DELTA-VAS was 6.42 in the group of patients imaged using DECT and 6.65 in the group imaged using MRI (p = 0.326). Inter-observer and intra-observer agreement were 0.85 and 0.89 for DECT, and 0.88 and 0.91 for MRI, respectively. CONCLUSION The outcome of vertebral compression fracture management was no different between the two groups of patients studied.
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Affiliation(s)
- Giovanni Foti
- Department of Radiology, IRCCS Sacro Cuore Don Calabria Hospital, Via Don A. Sempreboni 10, 37024, Negrar, VR, Italy
| | - Fabio Lombardo
- Department of Radiology, IRCCS Sacro Cuore Don Calabria Hospital, Via Don A. Sempreboni 10, 37024, Negrar, VR, Italy.
| | - Massimo Guerriero
- Clinical Research Unit, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy
| | - Tommaso Rodella
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiation Therapy "Tor Vergata", Rome, Italy
| | - Carmelo Cicciò
- Department of Radiology, IRCCS Sacro Cuore Don Calabria Hospital, Via Don A. Sempreboni 10, 37024, Negrar, VR, Italy
| | - Niccolò Faccioli
- Department of Radiology, Verona University Hospital, Verona, Italy
| | - Gerardo Serra
- Department of Anesthesia and Analgesic Therapy, IRCCS Sacro Cuore Don Calabria Hospital, Via Don A. Sempreboni 5, Negrar, Italy
| | - Guglielmo Manenti
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiation Therapy "Tor Vergata", Rome, Italy
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Hackenbroch C, Schüle S, Halt D, Zengerle L, Beer M. Metal Artifact Reduction With Tin Prefiltration in Computed Tomography: A Cadaver Study for Comparison With Other Novel Techniques. Invest Radiol 2022; 57:194-203. [PMID: 34482356 DOI: 10.1097/rli.0000000000000823] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES With the aging population and thus rising numbers of orthopedic implants (OIs), metal artifacts (MAs) increasingly pose a problem for computed tomography (CT) examinations. In the study presented here, different MA reduction techniques (iterative metal artifact reduction software [iMAR], tin prefilter technique, and dual-energy CT [DECT]) were compared. MATERIALS AND METHODS Four human cadaver pelvises with OIs were scanned on a third-generation DECT scanner using tin prefilter (Sn), dual-energy (DE), and conventional protocols. Virtual monoenergetic CT images were generated from DE data sets. Postprocessing of CT images was performed using iMAR. Qualitative (bony structures, MA, image noise) image analysis using a 6-point Likert scale and quantitative image analysis (contrast-to-noise ratio, standard deviation of background noise) were performed by 2 observers. Statistical testing was performed using Friedman test with Nemenyi test as a post hoc test. RESULTS The iMAR Sn 150 kV protocol provided the best overall assessability of bony structures and the lowest subjective image noise. The iMAR DE protocol and virtual monochromatic image (VMI) ± iMAR achieved the most effective metal artifact reduction (MAR) (P < 0.05 compared with conventional protocols). Bony structures were rated worse in VMI ± iMAR (P < 0.05) than in tin prefilter protocols ± iMAR. The DE protocol ± iMAR had the lowest contrast-to-noise ratio (P < 0.05 compared with iMAR standard) and the highest image noise (P < 0.05 compared with iMAR VMI). The iMAR reduced MA very efficiently. CONCLUSIONS When considering MAR and image quality, the iMAR Sn 150 kV protocol performed best overall in CT images with OI. The iMAR generated new artifacts that impaired image quality. The DECT/VMI reduced MA best, but experienced from a lack of resolution of bony fine structures.
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Affiliation(s)
| | - Simone Schüle
- From the Department of Diagnostic and Interventional Radiology and Neuroradiology, German Armed Forces Hospital of Ulm
| | - Daniel Halt
- From the Department of Diagnostic and Interventional Radiology and Neuroradiology, German Armed Forces Hospital of Ulm
| | - Laura Zengerle
- Institute of Orthopaedic Research and Biomechanics, University Hospital of Ulm, Ulm, Germany
| | - Meinrad Beer
- Department of Diagnostic and Interventional Radiology
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Vara G, Ceccarelli L, Ponti F, Miceli M, Golfieri R, Facchini G. Reduction of Metal Artifacts Caused by Titanium Peduncular Screws in the Spine by Means of Monoenergetic Images and the Metal Artifact Reduction Software in Dual-Energy Computed Tomography. J Med Phys 2022; 47:152-158. [PMID: 36212200 PMCID: PMC9543003 DOI: 10.4103/jmp.jmp_121_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/04/2022] Open
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21
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Single- and Dual-Source CT Myelography: Comparison of Radiation Exposure and Establishment of Diagnostic Reference Levels. Diagnostics (Basel) 2021; 11:diagnostics11101809. [PMID: 34679507 PMCID: PMC8534585 DOI: 10.3390/diagnostics11101809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 01/12/2023] Open
Abstract
CT myelography (CTM) is a diagnostic technique for the evaluation of various spinal pathologies, and plays an important role in diagnosis of different diseases such as spontaneous intracranial hypotension and postoperative cerebrospinal fluid leaks. The aims of this study were to examine radiation exposure, establish diagnostic reference levels (DRLs) and compare radiation doses of single- and dual-source examinations and different CTM protocols. In this retrospective study, 183 CTMs comprising 155 single-source and 28 dual-source examinations, performed between May 2015 and December 2020, were analyzed. Dose data included 31 whole spine (A), 23 cervical (B), 10 thoracic (C), and 119 lumbar (D) CTMs. Radiation exposure was reported for volume-weighted CT dose index (CTDIvol) and dose-length product (DLP). Radiation doses for CTDIvol and DLP were distributed as follows (median, IQR): A: 7.44 mGy (6.01–11.17 mGy)/509.7 mGy·cm (382.4–682.9 mGy·cm), B: 9.31 mGy (7.20–14.64 mGy)/214.5 mGy·cm (153.7–308.2 mGy·cm), C: 6.80 mGy (6.14–8.26 mGy)/365.4 mGy·cm (222.8–432.4 mGy·cm), D: 11.02 mGy (7.97–14.89 mGy)/308.0 mGy·cm (224.7–413.7 mGy·cm). Local DRLs could be depicted as follows (CTDIvol/DLP): A: 11 mGy/683 mGy·cm, B: 15 mGy/308 mGy·cm, C: 8 mGy/432 mGy·cm, D: 15 mGy/414 mGy·cm. High image quality was achieved for all anatomical regions. Basically, radiation exposure of CTM differs according to anatomical location.
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22
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Al-Haj Husain A, Valdec S, Stadlinger B, Rücker M, Piccirelli M, Winklhofer S. Preoperative visualization of the lingual nerve by 3D double-echo steady-state MRI in surgical third molar extraction treatment. Clin Oral Investig 2021; 26:2043-2053. [PMID: 34586501 PMCID: PMC8816737 DOI: 10.1007/s00784-021-04185-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/18/2021] [Indexed: 11/28/2022]
Abstract
Objectives To assess the lingual nerve (LN) visualization using a 3D double-echo steady-state MRI sequence (3D-DESS). Materials and methods Three readers prospectively evaluated the LN for its continuous visibility in 3D-DESS MRI in 19 patients with an indication for removal of mandibular impacted third molars, using a 5-point scale (4 = excellent to 0 = none). Six LN anatomical intermediate points (IP) were selected and checked for their detectability by a 4-point scale (4 = yes to1 = no). Inter- and intra-rater agreement was evaluated using intraclass correlation coefficient and percentage of agreement. Results The average nerve continuity score was 3.3 ± 0.46. In 35% of the cases, the entire course was continuously visible. In 10%, the proximal and 60%, the distal part of the nerve was not continuously visible. Inter- and intra-reader agreement was good (ICC = 0.76, ICC = 0.75). The average detectability score of all IP was 3.7 ± 0.41. From IP1 to IP5, the detectability was excellent; meanwhile, IP6 had lower visibility. The inter- and intra-reader percentage of agreement was 77% and 87%. Conclusions The 3D-DESS sequence allowed accurate and continuous visualization of the LN with high reproducibility in more than one-third of the patients. This could improve the preoperative clarification of the LN position and thereby reduce complications during dentoalveolar surgical interventions. Clinical relevance 3D-DESS MRI might be beneficial in clinical scenarios where the second molar is elongated or presents a difficult rotational position while simultaneously having a close positional relationship to the third molar. Thereby, osteotomy performed more lingually, indicating extended lingual flap detachment may increase the risk of LN damage. Supplementary Information The online version contains supplementary material available at 10.1007/s00784-021-04185-z.
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Affiliation(s)
- Adib Al-Haj Husain
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Silvio Valdec
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Bernd Stadlinger
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Martin Rücker
- Clinic of Cranio-Maxillofacial and Oral Surgery, University Hospital of Zurich, University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.
| | - Sebastian Winklhofer
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.
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Osterhoff G, Huber FA, Graf LC, Erdlen F, Pape HC, Sprengel K, Guggenberger R. Comparison of metal artifact reduction techniques in magnetic resonance imaging of carbon-reinforced PEEK and titanium spinal implants. Acta Radiol 2021; 63:1062-1070. [PMID: 34229463 DOI: 10.1177/02841851211029077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Carbon-reinforced PEEK (C-FRP) implants are non-magnetic and have increasingly been used for the fixation of spinal instabilities. PURPOSE To compare the effect of different metal artifact reduction (MAR) techniques in magnetic resonance imaging (MRI) on titanium and C-FRP spinal implants. MATERIAL AND METHODS Rod-pedicle screw constructs were mounted on ovine cadaver spine specimens and instrumented with either eight titanium pedicle screws or pedicle screws made of C-FRP and marked with an ultrathin titanium shell. MR scans were performed of each configuration on a 3-T scanner. MR sequences included transaxial conventional T1-weighted turbo spin echo (TSE) sequences, T2-weighted TSE, and short-tau inversion recovery (STIR) sequences and two different MAR-techniques: high-bandwidth (HB) and view-angle-tilting (VAT) with slice encoding for metal artifact correction (SEMAC). Metal artifact degree was assessed by qualitative and quantitative measures. RESULTS There was a much stronger effect on artifact reduction with using C-FRP implants compared to using specific MRI MAR-techniques (screw shank: P < 0.001; screw tulip: P < 0.001; rod: P < 0.001). VAT-SEMAC sequences were able to reduce screw-related signal loss artifacts in constructs with titanium screws to a certain degree. Constructs with C-FRP screws showed less artifact-related implant diameter amplification when compared to constructs with titanium screws (P < 0.001). CONCLUSION Constructs with C-FRP screws are associated with significantly less artifacts compared to constructs with titanium screws including dedicated MAR techniques. Artifact-reducing sequences are able to reduce implant-related artifacts. This effect is stronger in constructs with titanium screws than in constructs with C-FRP screws.
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Affiliation(s)
- Georg Osterhoff
- Department of Trauma, University Hospital Zurich, University Hospital Zurich, Zurich, Switzerland
- Department of Orthopaedics, Trauma and Plastic Surgery, University Hospital of Leipzig, Leipzig, Germany
| | - Florian A Huber
- Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland
| | - Laura C Graf
- Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland
| | - Ferdinand Erdlen
- Department of Trauma, University Hospital Zurich, University Hospital Zurich, Zurich, Switzerland
| | - Hans-Christoph Pape
- Department of Trauma, University Hospital Zurich, University Hospital Zurich, Zurich, Switzerland
| | - Kai Sprengel
- Department of Trauma, University Hospital Zurich, University Hospital Zurich, Zurich, Switzerland
| | - Roman Guggenberger
- Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland
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Choo HJ, Lee SJ, Kim DW, Lee YJ, Baek JW, Han JY, Heo YJ. Comparison of the Quality of Various Polychromatic and Monochromatic Dual-Energy CT Images with or without a Metal Artifact Reduction Algorithm to Evaluate Total Knee Arthroplasty. Korean J Radiol 2021; 22:1341-1351. [PMID: 34132074 PMCID: PMC8316773 DOI: 10.3348/kjr.2020.0548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 02/01/2021] [Accepted: 02/05/2021] [Indexed: 11/28/2022] Open
Abstract
Objective To compare the quality of various polychromatic and monochromatic images with or without using an iterative metal artifact reduction algorithm (iMAR) obtained from a dual-energy computed tomography (CT) to evaluate total knee arthroplasty. Materials and Methods We included 58 patients (28 male and 30 female; mean age [range], 71.4 [61–83] years) who underwent 74 knee examinations after total knee arthroplasty using dual-energy CT. CT image sets consisted of polychromatic image sets that linearly blended 80 kVp and tin-filtered 140 kVp using weighting factors of 0.4, 0, and −0.3, and monochromatic images at 130, 150, 170, and 190 keV. These image sets were obtained with and without applying iMAR, creating a total of 14 image sets. Two readers qualitatively ranked the image quality (1 [lowest quality] through 14 [highest quality]). Volumes of high- and low-density artifacts and contrast-to-noise ratios (CNRs) between the bone and fat tissue were quantitatively measured in a subset of 25 knees unaffected by metal artifacts. Results iMAR-applied, polychromatic images using weighting factors of −0.3 and 0.0 (P−0.3i and P0.0i, respectively) showed the highest image-quality rank scores (median of 14 for both by one reader and 13 and 14, respectively, by the other reader; p < 0.001). All iMAR-applied image series showed higher rank scores than the iMAR-unapplied ones. The smallest volumes of low-density artifacts were found in P−0.3i, P0.0i, and iMAR-applied monochromatic images at 130 keV. The smallest volumes of high-density artifacts were noted in P−0.3i. The CNRs were best in polychromatic images using a weighting factor of 0.4 with or without iMAR application, followed by polychromatic images using a weighting factor of 0.0 with or without iMAR application. Conclusion Polychromatic images combined with iMAR application, P−0.3i and P0.0i, provided better image qualities and substantial metal artifact reduction compared with other image sets.
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Affiliation(s)
- Hye Jung Choo
- Department of Radiology, Inje University Busan Paik Hospital, Busan, Korea.
| | - Sun Joo Lee
- Department of Radiology, Inje University Busan Paik Hospital, Busan, Korea
| | - Dong Wook Kim
- Department of Radiology, Inje University Busan Paik Hospital, Busan, Korea
| | - Yoo Jin Lee
- Department of Radiology, Inje University Busan Paik Hospital, Busan, Korea
| | - Jin Wook Baek
- Department of Radiology, Inje University Busan Paik Hospital, Busan, Korea
| | - Ji Yeon Han
- Department of Radiology, Inje University Busan Paik Hospital, Busan, Korea
| | - Young Jin Heo
- Department of Radiology, Inje University Busan Paik Hospital, Busan, Korea
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Hamid S, Nasir MU, So A, Andrews G, Nicolaou S, Qamar SR. Clinical Applications of Dual-Energy CT. Korean J Radiol 2021; 22:970-982. [PMID: 33856133 PMCID: PMC8154785 DOI: 10.3348/kjr.2020.0996] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/16/2020] [Accepted: 11/22/2020] [Indexed: 01/05/2023] Open
Abstract
Dual-energy CT (DECT) provides insights into the material properties of tissues and can differentiate between tissues with similar attenuation on conventional single-energy imaging. In the conventional CT scanner, differences in the X-ray attenuation between adjacent structures are dependent on the atomic number of the materials involved, whereas in DECT, the difference in the attenuation is dependent on both the atomic number and electron density. The basic principle of DECT is to obtain two datasets with different X-ray energy levels from the same anatomic region and material decomposition based on attenuation differences at different energy levels. In this article, we discuss the clinical applications of DECT and its potential robust improvements in performance and postprocessing capabilities.
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Affiliation(s)
- Saira Hamid
- Department of Radiology, University of British Columbia Hospital, University of British Columbia, Vancouver, Canada.
| | - Muhammad Umer Nasir
- Department of Medical Imaging, Vancouver General Hospital, University of British Columbia, Vancouver, Canada
| | - Aaron So
- Department of Medical Biophyics, Schulich School of Medicine and Dentistry Western University London, Ontario, Canada
| | - Gordon Andrews
- Department of Radiology, University of British Columbia Hospital, University of British Columbia, Vancouver, Canada
| | - Savvas Nicolaou
- Department of Medical Imaging, Vancouver General Hospital, University of British Columbia, Vancouver, Canada
| | - Sadia Raheez Qamar
- Department of Medical Imaging, Sunnybrook Hospital, University of Toronto, Toronto, Canada
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Rodríguez-Gallo Y, Orozco-Morales R, Pérez-Díaz M. Inpainting-filtering for metal artifact reduction (IMIF-MAR) in computed tomography. Phys Eng Sci Med 2021; 44:409-423. [PMID: 33761106 DOI: 10.1007/s13246-021-00990-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 03/05/2021] [Indexed: 12/28/2022]
Abstract
The reduction of metal artifacts remains a challenge in computed tomography because they decrease image quality, and consequently might affect the medical diagnosis. The objective of this study is to present a novel method to correct metal artifacts based solely on the CT-slices. The proposed method consists of four steps. First, metal implants in the original CT-slice are segmented using an entropy based method, producing a metal image. Second, a prior image is acquired using three transformations: Gaussian filter, Parisotto and Schoenlieb inpainting method with the Mumford-Shah image model and L0 Gradient Minimization method (L0GM). Next, based on the projections from the original CT-slice, prior image and metal image, the sinogram is corrected in the traces affected by metal in the process called normalization and denormalization. Finally, the reconstructed image is obtained by FBP and a Nonlocal Means (NLM) filtering. The efficacy of the algorithm is evaluated by comparing five image quality metrics of the images and by inspecting regions of interest (ROI). Phantom data as well as clinical datasets are included. The proposed method is compared with three established metal artifact reduction (MAR) methods. The results from a phantom and clinical dataset show the visible reduction of artifacts. The conclusion is that IMIF-MAR method can reduce streak metal artifacts effectively and avoid new artifacts around metal implants, while preserving the anatomical structures. Considering both clinical and phantom studies, the proposed MAR algorithm improves the quality of clinical images affected by metal artifacts, and could be integrated in clinical setting.
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Affiliation(s)
- Yakdiel Rodríguez-Gallo
- Departamento de Electrónica y Telecomunicaciones, Universidad Central 'Marta Abreu' de Las Villas, Santa Clara, Cuba
| | - Rubén Orozco-Morales
- Departamento de Control Automático, Universidad Central 'Marta Abreu' de Las Villas, Carretera a Camajuani km 5 ½, 54830, Santa Clara, Villa Clara, Cuba
| | - Marlen Pérez-Díaz
- Departamento de Control Automático, Universidad Central 'Marta Abreu' de Las Villas, Carretera a Camajuani km 5 ½, 54830, Santa Clara, Villa Clara, Cuba.
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Low-Dose MDCT of Patients With Spinal Instrumentation Using Sparse Sampling: Impact on Metal Artifacts. AJR Am J Roentgenol 2021; 216:1308-1317. [PMID: 33703925 DOI: 10.2214/ajr.20.23083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE. The purpose of our study was to evaluate simulated sparse-sampled MDCT combined with statistical iterative reconstruction (SIR) for low-dose imaging of patients with spinal instrumentation. MATERIALS AND METHODS. Thirty-eight patients with implanted hardware after spinal instrumentation (24 patients with short- or long-term instrumentation-related complications [i.e., adjacent segment disease, screw loosening or implant failure, or postoperative hematoma or seroma] and 14 control subjects with no complications) underwent MDCT. Scans were simulated as if they were performed with 50% (P50), 25% (P25), 10% (P10), and 5% (P5) of the projections of the original acquisition using an in-house-developed SIR algorithm for advanced image reconstructions. Two readers performed qualitative image evaluations of overall image quality and artifacts, image contrast, inspection of the spinal canal, and diagnostic confidence (1 = high, 2 = medium, and 3 = low confidence). RESULTS. Although overall image quality decreased and artifacts increased with reductions in the number of projections, all complications were detected by both readers when 100% of the projections of the original acquisition (P100), P50, and P25 imaging data were used. For P25 data, diagnostic confidence was still high (mean score ± SD: reader 1, 1.2 ± 0.4; reader 2, 1.3 ± 0.5), and interreader agreement was substantial to almost perfect (weighted Cohen κ = 0.787-0.855). The mean volumetric CT dose index was 3.2 mGy for P25 data in comparison with 12.6 mGy for the original acquisition (P100 data). CONCLUSION. The use of sparse sampling and SIR for low-dose MDCT in patients with spinal instrumentation facilitated considerable reductions in radiation exposure. The use of P25 data with SIR resulted in no missed complications related to spinal instrumentation and allowed high diagnostic confidence, so using only 25% of the projections is probably enough for accurate and confident diagnostic detection of major instrumentation-related complications.
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Huber FA, Sprengel K, Müller L, Graf LC, Osterhoff G, Guggenberger R. Comparison of different CT metal artifact reduction strategies for standard titanium and carbon-fiber reinforced polymer implants in sheep cadavers. BMC Med Imaging 2021; 21:29. [PMID: 33588781 PMCID: PMC7885519 DOI: 10.1186/s12880-021-00554-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/31/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND CT artifacts induced by orthopedic implants can limit image quality and diagnostic yield. As a number of different strategies to reduce artifact extent exist, the aim of this study was to systematically compare ex vivo the impact of different CT metal artifact reduction (MAR) strategies on spine implants made of either standard titanium or carbon-fiber-reinforced-polyetheretherketone (CFR-PEEK). METHODS Spine surgeons fluoroscopically-guided prepared six sheep spine cadavers with pedicle screws and rods of either titanium or CFR-PEEK. Samples were subjected to single- and dual-energy (DE) CT-imaging. Different tube voltages (80, DE mixed, 120 and tin-filtered 150 kVp) at comparable radiation dose and iterative reconstruction versus monoenergetic extrapolation (ME) techniques were compared. Also, the influence of image reconstruction kernels (soft vs. bone tissue) was investigated. Qualitative (Likert scores) and quantitative parameters (attenuation changes induced by implant artifact, implant diameter and image noise) were evaluated by two independent radiologists. Artifact degree of different MAR-strategies and implant materials were compared by multiple ANOVA analysis. RESULTS CFR-PEEK implants induced markedly less artifacts than standard titanium implants (p < .001). This effect was substantially larger than any other tested MAR technique. Reconstruction algorithms had small impact in CFR-PEEK implants and differed significantly in MAR efficiency (p < .001) with best MAR performance for DECT ME 130 keV (bone kernel). Significant differences in image noise between reconstruction kernels were seen (p < .001) with minor impact on artifact degree. CONCLUSIONS CFR-PEEK spine implants induce significantly less artifacts than standard titanium compositions with higher MAR efficiency than any alternate scanning or image reconstruction strategy. DECT ME 130 keV image reconstructions showed least metal artifacts. Reconstruction kernels primarily modulate image noise with minor impact on artifact degree.
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Affiliation(s)
- Florian A Huber
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Faculty of Medicine, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
| | - Kai Sprengel
- Department of Trauma, University Hospital Zurich, Faculty of Medicine, University of Zurich, 8091, Zurich, Switzerland
| | - Lydia Müller
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Faculty of Medicine, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Laura C Graf
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Faculty of Medicine, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Georg Osterhoff
- Department of Trauma, University Hospital Zurich, Faculty of Medicine, University of Zurich, 8091, Zurich, Switzerland.,Department of Orthopaedics, Trauma and Plastic Surgery, University Hospital Leipzig, 04103, Leipzig, Germany
| | - Roman Guggenberger
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Faculty of Medicine, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
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Machine Learning and Deep Neural Networks: Applications in Patient and Scan Preparation, Contrast Medium, and Radiation Dose Optimization. J Thorac Imaging 2021; 35 Suppl 1:S17-S20. [PMID: 32079904 DOI: 10.1097/rti.0000000000000482] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Artificial intelligence (AI) algorithms are dependent on a high amount of robust data and the application of appropriate computational power and software. AI offers the potential for major changes in cardiothoracic imaging. Beyond image processing, machine learning and deep learning have the potential to support the image acquisition process. AI applications may improve patient care through superior image quality and have the potential to lower radiation dose with AI-driven reconstruction algorithms and may help avoid overscanning. This review summarizes recent promising applications of AI in patient and scan preparation as well as contrast medium and radiation dose optimization.
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Performance of single-energy metal artifact reduction in cardiac computed tomography: A clinical and phantom study. J Cardiovasc Comput Tomogr 2020; 14:510-515. [DOI: 10.1016/j.jcct.2020.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 04/01/2020] [Accepted: 04/13/2020] [Indexed: 12/11/2022]
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Barreto I, Pepin E, Davis I, Dean C, Massini T, Rees J, Olguin C, Quails N, Correa N, Rill L, Arreola M. Comparison of metal artifact reduction using single-energy CT and dual-energy CT with various metallic implants in cadavers. Eur J Radiol 2020; 133:109357. [PMID: 33126172 DOI: 10.1016/j.ejrad.2020.109357] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/15/2020] [Accepted: 10/12/2020] [Indexed: 12/27/2022]
Abstract
OBJECTIVES The purpose of this study was to compare the effectiveness of metal artifact reduction using Single Energy Metal Artifact Reduction (SEMAR) and Dual Energy CT (DECT). MATERIALS AND METHODS Six cadavers containing metal implants in the head, neck, abdomen, pelvis, and extremities were scanned with Standard, SEMAR, and DECT protocols on a 320-slice CT scanner. Four specialized radiologists blinded to acquisition methods rated severity of metal artifacts, visualization of anatomic structures, diagnostic interpretation, and image preference with a 5-point grading scale. RESULTS Scores were significantly better for SEMAR than Standard images in the hip, knee, pelvis, abdomen, and maxillofacial scans (3.25 ± 0.88 versus 2.14 ± 0.93, p < 0.001). However, new reconstruction artifacts developed in SEMAR images that were not present in Standard images. Scores for severity of metal artifacts and visualization of smooth structures were significantly better for DECT than Standard images in the cervical spine (3.50±0.50 versus 2.0±0.58, p < 0.001) and was preferred over Standard images by one radiologist. In all other cases, radiologists preferred the Standard image over the DECT image due to increased image noise and reduced low-contrast resolution with DECT. In all cases, SEMAR was preferred over Standard and DECT images. CONCLUSION SEMAR was more effective at reducing metal artifacts than DECT. Radiologists should be aware of new artifacts and review both the original and SEMAR images. When the anatomy or implant is relatively small, DECT may be superior to SEMAR without additional artifacts. However, radiologist should be aware of a reduction in soft tissue contrast.
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Affiliation(s)
- Izabella Barreto
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - Eric Pepin
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390, United States.
| | - Ivan Davis
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - Cooper Dean
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - Tara Massini
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - John Rees
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - Catherine Olguin
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - Nathan Quails
- Department of Radiology, Ohio State University Wexner Medical Center, 395 W 12th Ave 4th Fl, Columbus, OH 43210, United States.
| | - Nathalie Correa
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - Lynn Rill
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
| | - Manuel Arreola
- Department of Radiology, College of Medicine, University of Florida, PO Box 100374, Gainesville, FL 32610-0374, United States.
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Schmidt B, Flohr T. Principles and applications of dual source CT. Phys Med 2020; 79:36-46. [PMID: 33115699 DOI: 10.1016/j.ejmp.2020.10.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 01/03/2023] Open
Abstract
This article describes the technical principles and clinical applications of dual source CT. A dual source CT (DSCT) is a CT system with two x-ray tubes and two detectors at an angle of approximately 90°. Both measurement systems acquire CT scan data simultaneously at the same anatomical level of the patient (same z-position). DSCT provides temporal resolution of approximately a quarter of the gantry rotation time for cardiac, cardio-thoracic and pediatric imaging. Successful imaging of the heart and the coronary arteries at high and variable heart rates has been demonstrated. DSCT systems can be operated at twice the spiral pitch of single source CT systems (up to pitch 3.2). The resulting high table speed is beneficial for pediatric applications and fast CT angiographic scans, e. g. of the aorta or the extremities. Operating both X-ray tubes at different tube potential (kV) enables the acquisition of dual energy data and the corresponding applications such as monoenergetic imaging and computation of material maps. Spectral separation can be improved by different filtration of the X-ray beams of both X-ray tubes. As a downside, DSCT systems have to cope with some challenges, among them the limited size of the second measurement system, and cross-scattered radiation.
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Affiliation(s)
- Bernhard Schmidt
- Siemens Healthcare GmbH, Computed Tomography, Siemensstr. 3, 91301 Forchheim, Germany.
| | - Thomas Flohr
- Siemens Healthcare GmbH, Computed Tomography, Siemensstr. 3, 91301 Forchheim, Germany
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Noid G, Zhu J, Tai A, Mistry N, Schott D, Prah D, Paulson E, Schultz C, Li XA. Improving Structure Delineation for Radiation Therapy Planning Using Dual-Energy CT. Front Oncol 2020; 10:1694. [PMID: 32984048 PMCID: PMC7484725 DOI: 10.3389/fonc.2020.01694] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/29/2020] [Indexed: 12/11/2022] Open
Affiliation(s)
- George Noid
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Justin Zhu
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - An Tai
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Nilesh Mistry
- Siemens Medical Solutions USA, Inc., Malvern, PA, United States
| | - Diane Schott
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Douglas Prah
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Eric Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Christopher Schultz
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - X. Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States
- *Correspondence: X. Allen Li,
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Protocol Optimization and Implementation of Dual-Energy and Dual-Source Computed Tomography in Clinical Practice: Field of View, Speed, or Material Separation? J Comput Assist Tomogr 2020; 44:610-618. [PMID: 32558772 DOI: 10.1097/rct.0000000000001039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Clinical use of dual-energy computed tomography (DECT) and dual-source computed tomography (DSCT) has been well established for more than a decade. Improved software and decreased postprocessing time have increased the advantages and availability of DECT and DSCT imaging. In this article, we will provide a practical guide for implementation of DECT and DSCT in clinical practice and discuss automated processing and selection of CT protocols in neurologic, cardiothoracic, vascular, body, and musculoskeletal imaging.
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Ghodasara N, Yi PH, Clark K, Fishman EK, Farshad M, Fritz J. Postoperative Spinal CT: What the Radiologist Needs to Know. Radiographics 2020; 39:1840-1861. [PMID: 31589573 DOI: 10.1148/rg.2019190050] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
During the past 2 decades, the number of spinal surgeries performed annually has been steadily increasing, and these procedures are being accompanied by a growing number of postoperative imaging studies to interpret. CT is accurate for identifying the location and integrity of implants, assessing the success of decompression and intervertebral arthrodesis procedures, and detecting and characterizing related complications. Although postoperative spinal CT is often limited owing to artifacts caused by metallic implants, parameter optimization and advanced metal artifact reduction techniques, including iterative reconstruction and monoenergetic extrapolation methods, can be used to reduce metal artifact severity and improve image quality substantially. Commonly used and recently available spinal implants and prostheses include screws and wires, static and extendable rods, bone grafts and biologic materials, interbody cages, and intervertebral disk prostheses. CT assessment and the spectrum of complications that can occur after spinal surgery and intervertebral arthroplasty include those related to the position and integrity of implants and prostheses, adjacent segment degeneration, collections, fistulas, pseudomeningoceles, cerebrospinal fluid leaks, and surgical site infections. Knowledge of the numerous spinal surgery techniques and devices aids in differentiating expected postoperative findings from complications. The various types of spinal surgery instrumentation and commonly used spinal implants are reviewed. The authors also describe and illustrate normal postoperative spine findings, signs of successful surgery, and the broad spectrum of postoperative complications that can aid radiologists in generating reports that address issues that the surgeon needs to know for optimal patient management.©RSNA, 2019.
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Affiliation(s)
- Nevil Ghodasara
- From the Russell H. Morgan Department of Radiology and Radiologic Science (N.G., P.H.Y., K.C.), Sections of Body CT (E.K.F.) and Musculoskeletal Radiology (J.F.), Johns Hopkins Hospital, 601 N Caroline St, Room 3014, Baltimore, MD 21287; and Spine Division, Department of Orthopedics, Balgrist University Hospital Zurich, Zurich, Switzerland (M.F.)
| | - Paul H Yi
- From the Russell H. Morgan Department of Radiology and Radiologic Science (N.G., P.H.Y., K.C.), Sections of Body CT (E.K.F.) and Musculoskeletal Radiology (J.F.), Johns Hopkins Hospital, 601 N Caroline St, Room 3014, Baltimore, MD 21287; and Spine Division, Department of Orthopedics, Balgrist University Hospital Zurich, Zurich, Switzerland (M.F.)
| | - Karen Clark
- From the Russell H. Morgan Department of Radiology and Radiologic Science (N.G., P.H.Y., K.C.), Sections of Body CT (E.K.F.) and Musculoskeletal Radiology (J.F.), Johns Hopkins Hospital, 601 N Caroline St, Room 3014, Baltimore, MD 21287; and Spine Division, Department of Orthopedics, Balgrist University Hospital Zurich, Zurich, Switzerland (M.F.)
| | - Elliot K Fishman
- From the Russell H. Morgan Department of Radiology and Radiologic Science (N.G., P.H.Y., K.C.), Sections of Body CT (E.K.F.) and Musculoskeletal Radiology (J.F.), Johns Hopkins Hospital, 601 N Caroline St, Room 3014, Baltimore, MD 21287; and Spine Division, Department of Orthopedics, Balgrist University Hospital Zurich, Zurich, Switzerland (M.F.)
| | - Mazda Farshad
- From the Russell H. Morgan Department of Radiology and Radiologic Science (N.G., P.H.Y., K.C.), Sections of Body CT (E.K.F.) and Musculoskeletal Radiology (J.F.), Johns Hopkins Hospital, 601 N Caroline St, Room 3014, Baltimore, MD 21287; and Spine Division, Department of Orthopedics, Balgrist University Hospital Zurich, Zurich, Switzerland (M.F.)
| | - Jan Fritz
- From the Russell H. Morgan Department of Radiology and Radiologic Science (N.G., P.H.Y., K.C.), Sections of Body CT (E.K.F.) and Musculoskeletal Radiology (J.F.), Johns Hopkins Hospital, 601 N Caroline St, Room 3014, Baltimore, MD 21287; and Spine Division, Department of Orthopedics, Balgrist University Hospital Zurich, Zurich, Switzerland (M.F.)
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Schwartz FR, Tailor T, Gaca JG, Kiefer T, Harrison K, Hughes GC, Ramirez-Giraldo JC, Marin D, Hurwitz LM. Impact of dual energy cardiac CT for metal artefact reduction post aortic valve replacement. Eur J Radiol 2020; 129:109135. [PMID: 32590257 DOI: 10.1016/j.ejrad.2020.109135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE Assess image quality of dual-energy (DE) and single-energy (SE) cardiac multi-detector computed tomographic (MDCT) post aortic valve replacement (AVR) on a dual source MDCT scanner. METHODS Eighty patients with cardiac MDCT acquisitions (ECG gated, dual-source) post-surgical and transcatheter AVR were retrospectively identified. Forty DE (cohort 1) and 40 SE acquisitions (cohort 2; 100 or 120 kVp) were reviewed. Metal artefact at valve coaptation (VC) and valve insertion site (VIS), and contrast enhancement were assessed. Valve leaflet edge definition was graded on a 4-point scale by three radiologists. RESULTS The mean percentage valve area obscured by metal artifact differed between the cohorts; cohort 1 DE blended, high keV and low keV: 14.8 %, 11.1 % and 17.8 % at VC and 16.4 %, 13 %, 20.4 % at VIS respectively. Cohort 2: 25.8 % and 33.6 % (VC and VIS); each DE reconstruction vs SE: P < 0.0001. Average contrast opacification and coefficient of variance for cohort 1: 562.9 ± 144.7, 281.1 ± 60.3 and 1132.7 ± 300.8 Hounsfield Units (HU) and 9.6 %, 10 % and 8.9 %. For cohort 2: 437.2 ± 119.2 HU and 10.8 % (P < 0.01). Average leaflet edge definition cohort 1: 2.3 ± 0.4, 2.7 ± 0.2 and 2.3 ± 0.2, and cohort 2: 2.9 ± 0.2. CONCLUSION DE high keV renderings can result in up to 17.2 % less metal artefact compared to standard SE acquisition for cardiac CT. Contrast opacification and homogeneity is higher for DE blended and low keV renderings compared to SE acquisition with leaflet visibility preferred for low keV and blended DE renderings.
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Affiliation(s)
- Fides Regina Schwartz
- Department of Radiology, Duke University Medical Center, Durham, NC 27705, United States.
| | - Tina Tailor
- Department of Radiology, Duke University Medical Center, Durham, NC 27705, United States
| | - Jeffrey G Gaca
- Department of Cardiothoracic Surgery, Duke University Medical Center, Durham, NC 27705, United States
| | - Todd Kiefer
- Department of Cardiology, Duke University Medical Center, Durham, NC 27705, United States
| | - Kevin Harrison
- Department of Cardiology, Duke University Medical Center, Durham, NC 27705, United States
| | - G Chad Hughes
- Department of Cardiothoracic Surgery, Duke University Medical Center, Durham, NC 27705, United States
| | | | - Daniele Marin
- Department of Radiology, Duke University Medical Center, Durham, NC 27705, United States
| | - Lynne M Hurwitz
- Department of Radiology, Duke University Medical Center, Durham, NC 27705, United States
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Vaishnav JY, Ghammraoui B, Leifer M, Zeng R, Jiang L, Myers KJ. CT metal artifact reduction algorithms: Toward a framework for objective performance assessment. Med Phys 2020; 47:3344-3355. [PMID: 32406534 PMCID: PMC7496341 DOI: 10.1002/mp.14231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 04/05/2020] [Accepted: 04/29/2020] [Indexed: 12/26/2022] Open
Abstract
Purpose Although several metal artifact reduction (MAR) algorithms for computed tomography (CT) scanning are commercially available, no quantitative, rigorous, and reproducible method exists for assessing their performance. The lack of assessment methods poses a challenge to regulators, consumers, and industry. We explored a phantom‐based framework for assessing an important aspect of MAR performance: how applying MAR in the presence of metal affects model observer performance at a low‐contrast detectability (LCD) task This work is, to our knowledge, the first model observer–based framework for the evaluation of MAR algorithms in the published literature. Methods We designed a numerical head phantom with metal implants. In order to incorporate an element of randomness, the phantom included a rotatable inset with an inhomogeneous background. We generated simulated projection data for the phantom. We applied two variants of a simple MAR algorithm, sinogram inpainting, to the projection data, that we reconstructed using filtered backprojection. To assess how MAR affected observer performance, we examined the detectability of a signal at the center of a region of interest (ROI) by a channelized Hotelling observer (CHO). As a figure of merit, we used the area under the ROC curve (AUC). Results We used simulation to test our framework on two variants of the MAR technique of sinogram inpainting. We found that our method was able to resolve the difference in two different MAR algorithms’ effect on LCD task performance, as well as the difference in task performances when MAR was applied, vs not. Conclusion We laid out a phantom‐based framework for objective assessment of how MAR impacts low‐contrast detectability, that we tested on two MAR algorithms. Our results demonstrate the importance of testing MAR performance over a range of object and imaging parameters, since applying MAR does not always improve the quality of an image for a given diagnostic task. Our framework is an initial step toward developing a more comprehensive objective assessment method for MAR, which would require developing additional phantoms and methods specific to various clinical applications of MAR, and increasing study efficiency.
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Affiliation(s)
- J Y Vaishnav
- Diagnostic X-Ray Systems Branch, Office of In Vitro Diagnostic Devices and Radiological Health, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA.,Canon Medical Systems, USA, Inc., 2441 Michelle Drive, Tustin, CA, 92780, USA
| | - B Ghammraoui
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - M Leifer
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - R Zeng
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - L Jiang
- Diagnostic X-Ray Systems Branch, Office of In Vitro Diagnostic Devices and Radiological Health, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
| | - K J Myers
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food & Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD, 20993, USA
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McCollough CH, Boedeker K, Cody D, Duan X, Flohr T, Halliburton SS, Hsieh J, Layman RR, Pelc NJ. Principles and applications of multienergy CT: Report of AAPM Task Group 291. Med Phys 2020; 47:e881-e912. [DOI: 10.1002/mp.14157] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/11/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Affiliation(s)
| | - Kirsten Boedeker
- Canon (formerly Toshiba) Medical Systems Corporation 1440 Warnall Ave Los Angeles CA 90024 USA
| | - Dianna Cody
- University of Texas, M.D. Anderson Cancer Center 7163 Spanish Grant Galveston TX 77554‐7756 USA
| | - Xinhui Duan
- Southwestern Medical Center University of Texas 5323 Harry Hines Blvd Dallas TX 75390‐9071 USA
| | - Thomas Flohr
- Siemens Healthcare GmbH Siemensstr. 3 Forchheim BY 91031 Germany
| | | | - Jiang Hsieh
- GE Healthcare Technologies 3000 N. Grandview Blvd. W-1190 Waukesha WI 53188 USA
| | - Rick R. Layman
- University of Texas, M.D. Anderson Cancer Center 7163 Spanish Grant Galveston TX 77554‐7756 USA
| | - Norbert J. Pelc
- Stanford University 443 Via Ortega, Room 203 Stanford CA 94305‐4125 USA
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Große Hokamp N, Eck B, Siedek F, Pinto Dos Santos D, Holz JA, Maintz D, Haneder S. Quantification of metal artifacts in computed tomography: methodological considerations. Quant Imaging Med Surg 2020; 10:1033-1044. [PMID: 32489927 DOI: 10.21037/qims.2020.04.03] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Numerous methods for artifact quantification in computed tomography (CT) imaging have been suggested. This study evaluated their utility with regards to correspondence with visual artifact perception and reproducibility. Two titanium rods (5 and 10 mm) were examined with 25 different scanning- and image-reconstruction parameters resulting in different types and extents of artifacts. Four radiologists evaluated every image against each other using an in-house developed software. Rating was repeated two times (2,400 comparisons = 2 times × 4 readers × 300 comparisons). Rankings were combined to obtain a reference ranking. Proposed approaches for artifact quantification include manual measurement of attenuation, standard deviation and noise and sophisticated algorithm-based approaches within the image- and frequency-domain. Two radiologists conducted manual measurements twice while the aforementioned algorithms were implemented within the Matlab-Environment allowing for automated image analysis. The reference ranking was compared to all aforementioned methods for artifact quantification to identify suited approaches. Besides visual analysis, Kappa-statistics and intraclass correlation coefficients (ICC) were used. Intra- and Inter-reader agreements of visual artifact perception were excellent (ICC 0.85-0.92). No quantitative method was able to represent the exact ranking of visually perceived artifacts; however, ICC for manual measurements were low (ICC 0.25-0.97). The method that showed best correspondence and reproducibility used a Fourier-transformed linear ROI and lower-end frequency bins. Automated measurements of artifact extent should be preferred over manual measurements as the latter show a limited reproducibility. One method that allows for automated quantification of such artefacts is made available as an electronic supplement.
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Affiliation(s)
- Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Department of Radiology, University Hospitals Medical Center, Cleveland, OH, USA
| | - Brendan Eck
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Florian Siedek
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Daniel Pinto Dos Santos
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jasmin A Holz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Maintz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Stefan Haneder
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
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Zopfs D, Lennartz S, Pennig L, Glauner A, Abdullayev N, Bremm J, Große Hokamp N, Persigehl T, Kabbasch C, Borggrefe J, Laukamp KR. Virtual monoenergetic images and post-processing algorithms effectively reduce CT artifacts from intracranial aneurysm treatment. Sci Rep 2020; 10:6629. [PMID: 32313094 PMCID: PMC7170914 DOI: 10.1038/s41598-020-63574-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/01/2020] [Indexed: 11/09/2022] Open
Abstract
To evaluate artifact reduction by virtual monoenergetic images (VMI) and metal artifact reduction algorithms (MAR) as well as the combination of both approaches (VMIMAR) compared to conventional CT images (CI) as standard of reference. In this retrospective study, 35 patients were included who underwent spectral-detector CT (SDCT) with additional MAR-reconstructions due to artifacts from coils or clips. CI, VMI, MAR and VMIMAR (range: 100-200 keV, 10 keV-increment) were reconstructed. Region-of-interest based objective analysis was performed by assessing mean and standard deviation of attenuation (HU) in hypo- and hyperdense artifacts from coils and clips. Visually, extent of artifact reduction and diagnostic assessment were rated. Compared to CI, VMI ≥ 100 keV, MAR and VMIMAR between 100-200 keV increased attenuation in hypoattenuating artifacts (CI/VMI200keV/MAR/VMIMAR200keV, HU: -77.6 ± 81.1/-65.1 ± 103.2/-36.9 ± 27.7/-21.1 ± 26.7) and decreased attenuation in hyperattenuating artifacts (HU: 47.4 ± 32.3/42.1 ± 50.2/29.5 ± 18.9/20.8 ± 25.8). However, differences were only significant for MAR in hypodense and VMIMAR in hypo- and hyperdense artifacts (p < 0.05). Visually, hypo- and hyperdense artifacts were significantly reduced compared to CI by VMI≥140/100keV, MAR and VMIMAR≥100keV. Diagnostic assessment of surrounding brain tissue was significantly improved in VMI≥100keV, MAR and VMIMAR≥100keV. The combination of VMI and MAR facilitates a significant reduction of artifacts adjacent to intracranial coils and clips. Hence, if available, these techniques should be combined for optimal reduction of artifacts following intracranial aneurysm treatment.
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Affiliation(s)
- David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Else Kröner Forschungskolleg Clonal Evolution in Cancer, University Hospital Cologne, Weyertal 115b, 50931, Cologne, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Andreas Glauner
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nuran Abdullayev
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Johannes Bremm
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Thorsten Persigehl
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Christoph Kabbasch
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jan Borggrefe
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Kai Roman Laukamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA.
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA.
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Laukamp KR, Große Hokamp N, Alabar O, Obmann VC, Lennartz S, Zopfs D, Gilkeson R, Ramaiya N, Gupta A. Metal artifacts from sternal wires: evaluation of virtual monoenergetic images from spectral-detector CT for artifact reduction. Clin Imaging 2020; 60:249-256. [DOI: 10.1016/j.clinimag.2019.12.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 12/22/2019] [Accepted: 12/27/2019] [Indexed: 10/25/2022]
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Detection of Bone Marrow Edema in the Head and Neck With Dual-Energy CT: Ready for Clinical Use? AJR Am J Roentgenol 2020; 214:893-899. [DOI: 10.2214/ajr.19.21881] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Hakvoort E, Wellenberg R, Streekstra G. Quantifying near metal visibility using dual energy computed tomography and iterative metal artifact reduction in a fracture phantom. Phys Med 2020; 69:9-18. [DOI: 10.1016/j.ejmp.2019.11.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/21/2019] [Accepted: 11/05/2019] [Indexed: 10/25/2022] Open
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Albrecht MH, Vogl TJ, Martin SS, Nance JW, Duguay TM, Wichmann JL, De Cecco CN, Varga-Szemes A, van Assen M, Tesche C, Schoepf UJ. Review of Clinical Applications for Virtual Monoenergetic Dual-Energy CT. Radiology 2019; 293:260-271. [DOI: 10.1148/radiol.2019182297] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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45
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Dual-Energy CT in Musculoskeletal Imaging: What Is the Role Beyond Gout? AJR Am J Roentgenol 2019; 213:493-505. [DOI: 10.2214/ajr.19.21095] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Leadless Cardiac Pacemaker (LCP) without Diagnostic Relevant Artifacts in DualSource and DualEnergy-CT Examinations in First- to Third-Generation DSCT Scanner. Acad Radiol 2019; 26:1071-1076. [PMID: 30413293 DOI: 10.1016/j.acra.2018.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 11/24/2022]
Abstract
RATIONALE AND OBJECTIVES To identify the influence and artifact burden in cardiac CT imaging of a leadless cardiac pacemaker (LCP) performed with all three generations of DualSource CT (DSCT) Scanners. MATERIALS AND METHODS The LCP was examined in DSCT scanners of the first to third generation using DualEnergy (DECT) and DSCT as well as alterations of the current-time product. For DECT examinations, virtual monoenergetic images were computed manually on a dedicated workstation. Virtual voltage was manually selected by subjective assessment of the lowest artifact burden. Systematic variations of the pacemaker angle to the gantry were assessed, too. The angle was successively increased by 10°, ranging from 0° to 90°. Artifact burden was quantified on a five-point Likert scale (1- no artifacts, 2- few artifacts, 3- moderate artifacts, 4- many artifacts, and 5- massive artifacts). Likert values of 1-3 were considered diagnostic and assessed by two board-certified radiologists in consensus. RESULTS In total, 200 examinations were analyzed, a mean Likert value of 1.93 ± 0.61 was found overall. None of the images were assessed Likert value >3. The positioning evaluation showed a clear and significant reduction of artifact burden toward lower angles, (0°: 1.4 ± 0.5 vs. 90° 2.55 ± 0.51). At scanner level, second-generation DSCT performed significantly better (1.68 ± 0.47) than both other scanners. Comparison of technique (DECT vs. DSCT) revealed a significantly improved image quality in DSCT examinations. CONCLUSION LCP can be safely examined in DSCT scanner of the first to third generation with the evaluated protocols and techniques, which are currently in use. Artifact burden can be significantly reduced by aligning or approaching the LCP's longitudinal axis toward the scanner's z-axis.
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Reinartz SD, Imhoff M, Tolba R, Fischer F, Fischer EG, Teschner E, Koch S, Gärber Y, Isfort P, Gremse F. EIT monitors valid and robust regional ventilation distribution in pathologic ventilation states in porcine study using differential DualEnergy-CT (ΔDECT). Sci Rep 2019; 9:9796. [PMID: 31278297 PMCID: PMC6611907 DOI: 10.1038/s41598-019-45251-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 04/12/2019] [Indexed: 11/19/2022] Open
Abstract
It is crucial to precisely monitor ventilation and correctly diagnose ventilation-related pathological states for averting lung collapse and lung failure in Intensive Care Unit (ICU) patients. Although Electrical Impedance Tomography (EIT) may deliver this information continuously and non-invasively at bedside, to date there are no studies that systematically compare EIT and Dual Energy CT (DECT) during inspiration and expiration (ΔDECT) regarding varying physiological and ICU-typical pathological conditions such as atelectasis. This study aims to prove the accuracy of EIT through quantitative identification and monitoring of pathological ventilation conditions on a four-quadrant basis using ΔDECT. In a cohort of 13 pigs, this study investigated systematic changes in tidal volume (TV) and positive end-expiratory pressure (PEEP) under physiological ventilation conditions. Pathological ventilation conditions were established experimentally by single-lung ventilation and pulmonary saline lavage. Spirometric data were compared to voxel-based entire lung ΔDECT, and EIT intensities were compared to ΔDECT of a 12-cm slab of the lung around the EIT belt, the so called ΔDECTBelt. To validate ΔDECT data with spirometry, a Pearson’s correlation coefficient of 0.92 was found for 234 ventilation conditions. Comparing EIT intensity with ΔDECT(Belt), the correlation r = 0.84 was found. Normalized cross-correlation function (NCCF) between scaled global impedance (EIT) waveforms and global volume ventilator curves was r = 0.99 ± 0.003. The EIT technique correctly identified the ventilated lung in all cases of single-lung ventilation. In the four-quadrant based evaluation, which assesses the difference between end-expiratory lung volume (ΔEELV) and the corresponding parameter in EIT, i.e. the end-expiratory lung impedance (ΔEELI), the Pearson’s correlation coefficient of 0.94 was found. The respective Pearson’s correlation coefficients implies good to excellent concurrence between global and regional EIT ventilation data validated by ventilator spirometry and DECT imaging. By providing real-time images of the lung, EIT is a promising, EIT is a promising, clinically robust tool for bedside assessment of regional ventilation distribution and changes of end-expiratory lung volume.
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Affiliation(s)
- Sebastian D Reinartz
- Department of Diagnostic and Interventional Radiology, University Hospital, RWTH Aachen University, 52074, Aachen, Germany.
| | - Michael Imhoff
- Department for Medical Informatics, Biometry and Epidemiology, Ruhr University of Bochum, 44780, Bochum, Germany
| | - René Tolba
- Institute of Laboratory Animal Science, University Hospital, RWTH Aachen University, 52074, Aachen, Germany
| | - Felix Fischer
- Drägerwerk AG & Co. KGaA, Moislinger Allee 53-55, 23558, Lübeck, Germany
| | - Eike G Fischer
- Aix Scientifics CRO, Theaterstr. 7, 52062, Aachen, Germany
| | - Eckhard Teschner
- Drägerwerk AG & Co. KGaA, Moislinger Allee 53-55, 23558, Lübeck, Germany
| | - Sabine Koch
- Institute of Laboratory Animal Science, University Hospital, RWTH Aachen University, 52074, Aachen, Germany
| | - Yvo Gärber
- Drägerwerk AG & Co. KGaA, Moislinger Allee 53-55, 23558, Lübeck, Germany
| | - Peter Isfort
- Department of Diagnostic and Interventional Radiology, University Hospital, RWTH Aachen University, 52074, Aachen, Germany
| | - Felix Gremse
- Institute for Experimental Molecular Imaging, University Hospital, RWTH Aachen University, 52074, Aachen, Germany
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Optimization of Monoenergetic Extrapolations in Dual-Energy CT for Metal Artifact Reduction in Different Body Regions and Orthopedic Implants. Acad Radiol 2019; 26:e67-e74. [PMID: 30072295 DOI: 10.1016/j.acra.2018.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/21/2018] [Accepted: 06/21/2018] [Indexed: 11/20/2022]
Abstract
RATIONALE AND OBJECTIVES To define an optimal monoenergetic extrapolation (ME) in dual-energy computed tomography (DECT) for metal artifact reduction (MAR) including different body regions and orthopedic implants. MATERIAL AND METHODS DECT scans were acquired with dual-source CT (SOMATOM Force, Siemens, Germany) at tube voltage A 80-100 kV/B Sn150 kV from 39 patients (mean 54.1 ± 20.7 years, 23 male vs. 16 female) with orthopedic implants ranging from wires to joint implants. Scans were assembled in four groups based on scan regions and volume. Single- and weighted-energy images at a ratio of 0.3 and MEs at 100, 130, 160, and 190 keV were produced using vendor-specific postprocessing software (Syngo.Via, Siemens, Germany). Artifact degree was assessed quantitatively by metal-induced Hounsfield unit changes in relation to reference tissues. Visibility of screw-bone interface, hardware integrity, adjacent bone, and soft tissues were visually rated on a four-point Likert scale (0, none; 3, strong artifacts with nondiagnostic quality). Optimal energy was visually determined by side-by-side comparisons. Artifact degree was statistically compared between regions and energies. RESULTS Metal-induced attenuation changes were most severe in large scan volume groups for all energies. Reference tissue attenuation outside metal artifacts was not affected by ME (p = 0.57). Independent of region, ME at 130-190 keV quantitatively performed significantly better for MAR than the remainder. ME 130 keV showed the highest frequency (54%) in optimal energy ratings based on qualitative image criteria. CONCLUSION DECT significantly reduces image artifacts in patients with orthopedic hardware and prospective choice of ME at 130 keV may suit best for optimal MAR, independent of region or implant.
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D'Angelo T, Cicero G, Mazziotti S, Ascenti G, Albrecht MH, Martin SS, Othman AE, Vogl TJ, Wichmann JL. Dual energy computed tomography virtual monoenergetic imaging: technique and clinical applications. Br J Radiol 2019; 92:20180546. [PMID: 30919651 DOI: 10.1259/bjr.20180546] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Dual energy CT (DECT) has evolved into a commonly applied imaging technique in clinical routine due to its unique post-processing opportunities for improved evaluation of all body areas. Reconstruction of virtual monoenergetic imaging (VMI) series has shown beneficial effects for both non-contrast and contrast-enhanced DECT due to the flexibility to calculate low-keV VMI reconstructions to increase contrast and iodine attenuation, or to compute high-keV VMI reconstructions to reduce beam-hardening artefacts. The goal of this review article is to explain the technical background of VMI and noise-optimized VMI+ algorithms and to give an overview of useful clinical applications of the VMI technique in DECT of various body regions.
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Affiliation(s)
- Tommaso D'Angelo
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy.,2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Giuseppe Cicero
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy
| | - Silvio Mazziotti
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy
| | - Giorgio Ascenti
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy
| | - Moritz H Albrecht
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Simon S Martin
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Ahmed E Othman
- 3 Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tübingen , Tübingen , Germany
| | - Thomas J Vogl
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Julian L Wichmann
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
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Foti G, Beltramello A, Catania M, Rigotti S, Serra G, Carbognin G. Diagnostic accuracy of dual-energy CT and virtual non-calcium techniques to evaluate bone marrow edema in vertebral compression fractures. Radiol Med 2019; 124:487-494. [DOI: 10.1007/s11547-019-00998-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/24/2019] [Indexed: 10/27/2022]
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