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Khodarahmi I, Khanuja HS, Stern SE, Carrino JA, Fritz J. Compressed Sensing SEMAC MRI of Hip, Knee, and Ankle Arthroplasty Implants: A 1.5-T and 3-T Intrapatient Performance Comparison for Diagnosing Periprosthetic Abnormalities. AJR Am J Roentgenol 2023; 221:661-672. [PMID: 37255041 DOI: 10.2214/ajr.23.29380] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND. The utility of 3-T MRI for diagnosing joint disorders is established, but its performance for diagnosing abnormalities around arthroplasty implants is unclear. OBJECTIVE. The purpose of this study was to compare 1.5-T and 3-T compressed sensing slice encoding for metal artifact correction (SEMAC) MRI for diagnosing peri-prosthetic abnormalities around hip, knee, and ankle arthroplasty implants. METHODS. Forty-five participants (26 women, 19 men; mean age ± SD, 71 ± 14 years) with symptomatic lower extremity arthroplasty (hip, knee, and ankle, 15 each) prospectively underwent consecutive 1.5- and 3-T MRI examinations with intermediate-weighted (IW) and STIR compressed sensing SEMAC sequences. Using a Likert scale, three radiologists evaluated the presence or absence of periprosthetic abnormalities, including bone marrow edema-like signal, osteolysis, stress reaction/fracture, synovitis, and tendon abnormalities and collections; image quality; and visibility of anatomic structures. Statistical analysis included nonparametric comparison and interchangeability testing. RESULTS. For diagnosing periprosthetic abnormalities, 1.5-T and 3-T compressed sensing SEMAC MRI were interchangeable. Across all three joints, 3-T MRI had lower noise than 1.5-T MRI (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [range, 2-5 and 3-5] vs 3 and 3 [range, 2-5 and 2-4]; p < .01 for both), sharper edges (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [both ranges, 2-5] vs 3 and 3 [range, 2-4 and 2-5]; p < .02 and p < .05), and more effective metal artifact reduction (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [range, 3-5 and 2-5] vs 4 and 4 [both ranges, 3-5]; p < .02 and p = .72). Agreement was moderate to substantial for image contrast (IW and STIR, 0.66 and 0.54 [95% CI, 0.41-0.91 and 0.29-0.80]; p = .58 and p = .16) and joint capsule visualization (IW and STIR, 0.57 and 0.70 [range, 0.32-0.81 and 0.51-0.89]; p = .16 and p = .19). The bone-implant interface was more visible at 1.5 T (median IW and STIR scores, 4 and 4 [both ranges, 2-5] at 1.5 T vs 3 and 3 [both ranges, 2-5] at 3 T; p = .08 and p = .58), but periprosthetic tissues had superior visibility at 3 T (IW and STIR, 4 and 4 [both ranges, 3-5] at 3 T vs 4 and 4 [ranges, 2-5 and 3-5] at 1.5 T; p = .07 and p = .19). CONCLUSION. Optimized 1.5-T and 3-T compressed sensing SEMAC MRI are interchangeable for diagnosing periprosthetic abnormalities, although metallic artifacts are larger at 3 T. CLINICAL IMPACT. With compressed sensing SEMAC MRI, lower extremity arthroplasty implants can be imaged at 3 T rather than 1.5 T.
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Affiliation(s)
- Iman Khodarahmi
- Department of Radiology, NYU Grossman School of Medicine, 660 1st Ave, 3rd Fl, Rm 313, New York, NY 10016
| | - Harpal S Khanuja
- Department of Orthopaedic Surgery, Johns Hopkins School of Medicine, Baltimore, MD
| | - Steven E Stern
- Centre for Data Analytics, Bond University, Gold Coast, Australia
| | - John A Carrino
- Department of Radiology, Hospital for Special Surgery, New York, NY
| | - Jan Fritz
- Department of Radiology, NYU Grossman School of Medicine, 660 1st Ave, 3rd Fl, Rm 313, New York, NY 10016
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Eck BL, Yang M, Elias JJ, Winalski CS, Altahawi F, Subhas N, Li X. Quantitative MRI for Evaluation of Musculoskeletal Disease: Cartilage and Muscle Composition, Joint Inflammation, and Biomechanics in Osteoarthritis. Invest Radiol 2023; 58:60-75. [PMID: 36165880 PMCID: PMC10198374 DOI: 10.1097/rli.0000000000000909] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ABSTRACT Magnetic resonance imaging (MRI) is a valuable tool for evaluating musculoskeletal disease as it offers a range of image contrasts that are sensitive to underlying tissue biochemical composition and microstructure. Although MRI has the ability to provide high-resolution, information-rich images suitable for musculoskeletal applications, most MRI utilization remains in qualitative evaluation. Quantitative MRI (qMRI) provides additional value beyond qualitative assessment via objective metrics that can support disease characterization, disease progression monitoring, or therapy response. In this review, musculoskeletal qMRI techniques are summarized with a focus on techniques developed for osteoarthritis evaluation. Cartilage compositional MRI methods are described with a detailed discussion on relaxometric mapping (T 2 , T 2 *, T 1ρ ) without contrast agents. Methods to assess inflammation are described, including perfusion imaging, volume and signal changes, contrast-enhanced T 1 mapping, and semiquantitative scoring systems. Quantitative characterization of structure and function by bone shape modeling and joint kinematics are described. Muscle evaluation by qMRI is discussed, including size (area, volume), relaxometric mapping (T 1 , T 2 , T 1ρ ), fat fraction quantification, diffusion imaging, and metabolic assessment by 31 P-MR and creatine chemical exchange saturation transfer. Other notable technologies to support qMRI in musculoskeletal evaluation are described, including magnetic resonance fingerprinting, ultrashort echo time imaging, ultrahigh-field MRI, and hybrid MRI-positron emission tomography. Challenges for adopting and using qMRI in musculoskeletal evaluation are discussed, including the need for metal artifact suppression and qMRI standardization.
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Affiliation(s)
- Brendan L. Eck
- Program of Advanced Musculoskeletal Imaging, Cleveland Clinic, Cleveland, OH, USA
- Imaging Instute, Cleveland Clinic, Cleveland, OH, USA
| | - Mingrui Yang
- Program of Advanced Musculoskeletal Imaging, Cleveland Clinic, Cleveland, OH, USA
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - John J. Elias
- Program of Advanced Musculoskeletal Imaging, Cleveland Clinic, Cleveland, OH, USA
- Department of Research, Cleveland Clinic Akron General, Akron, OH, USA
| | - Carl S. Winalski
- Program of Advanced Musculoskeletal Imaging, Cleveland Clinic, Cleveland, OH, USA
- Imaging Instute, Cleveland Clinic, Cleveland, OH, USA
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Faysal Altahawi
- Program of Advanced Musculoskeletal Imaging, Cleveland Clinic, Cleveland, OH, USA
- Imaging Instute, Cleveland Clinic, Cleveland, OH, USA
| | - Naveen Subhas
- Program of Advanced Musculoskeletal Imaging, Cleveland Clinic, Cleveland, OH, USA
- Imaging Instute, Cleveland Clinic, Cleveland, OH, USA
| | - Xiaojuan Li
- Program of Advanced Musculoskeletal Imaging, Cleveland Clinic, Cleveland, OH, USA
- Imaging Instute, Cleveland Clinic, Cleveland, OH, USA
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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Evaluating Compressed SENSE (CS) MRI Metal Artifact Reduction Using Pig L-Spine Phantom and Transplant Patients: Focused on the CS-SEMAC (SPIR), mDixon(O-MAR) and STIR Techniques. Tomography 2022; 8:2298-2312. [PMID: 36136888 PMCID: PMC9498365 DOI: 10.3390/tomography8050192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/29/2022] [Accepted: 09/07/2022] [Indexed: 11/30/2022] Open
Abstract
This study evaluates the clinical usefulness of the images obtained after applying mDixon (O-MAR), CS-SEMAC (SPIR), and STIR techniques to Pig L-Spine Phantom and transplant patients according to the difference in the reduction in metal artifacts and provides the optimal MAR image technique. This study was conducted with Phantom and 30 transplant patients who had an implant on the L-Spine (22 men, 8 women, mean age: 64.2 ± 12.98). All data analyzed were evaluated, using Philips Ingenia 3.0T CX. As pulse sequences, applied to the analysis, mDixon (O-MAR), CS-SEMAC (SPIR), and STIR were used. As the coil used to obtain data, the dStream Head Spine Coil was used. When tested directly applying to the transplant patients in the conditions the same as for the Phantom, as for the MAR effect of T1 and T2 images, the SNR value showed the highest effect on the increase in the signal in T1, T2 CS-SEMAC (SPIR), followed by mDixon (O-MAR) and STIR, which was the same result as the Phantom (p < 0.05). In addition, in the results of the histogram measurement in both of the subjects, Phantom and transplant patients, the count of T1, the T2 Sagittal image was the highest in T1, T2 STIR, followed by T1, T2 mDixon (O-MAR) and T1, and T2 CS-SEMAC (SPIR). As a result of the qualitative analysis, the quality was the best in T2 CS-SEMAC(SPIR) (c), followed by mDixon (O-MAR) (b) and T2 STIR (a). In conclusion, when the MAR effect on the Pig L-spine Phantom and Transplant patients was compared, it was noted that the CS-SEMAC (SPIR) technique was the most excellent in the following order: STIR < mDixon (O-MAR) < CS-SEMAC (SPIR).
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Espiritu J, Berangi M, Yiannakou C, Silva E, Francischello R, Kuehne A, Niendorf T, Könneker S, Willumeit-Römer R, Seitz JM. Evaluating metallic artefact of biodegradable magnesium-based implants in magnetic resonance imaging. Bioact Mater 2022; 15:382-391. [PMID: 35386351 PMCID: PMC8958470 DOI: 10.1016/j.bioactmat.2021.11.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/12/2021] [Accepted: 11/28/2021] [Indexed: 11/13/2022] Open
Abstract
Magnesium (Mg) implants have shown to cause image artefacts or distortions in magnetic resonance imaging (MRI). Yet, there is a lack of information on how the degradation of Mg-based implants influences the image quality of MRI examinations. In this study, Mg-based implants are analysed in vitro, ex vivo, and in the clinical setting for various magnetic field strengths with the aim to quantify metallic artefact behaviour. In vitro corroded Mg-based screws and a titanium (Ti) equivalent were imaged according to the ASTM F2119. Mg-based and Ti pins were also implanted into rat femurs for different time points and scanned to provide insights on the influence of soft and hard tissue on metallic artefact. Additionally, MRI data of patients with scaphoid fractures treated with CE-approved Mg-based compression screws (MAGNEZIX®) were analysed at various time points post-surgery. The artefact production of the Mg-based material decreased as implant material degraded in all settings. The worst-case imaging scenario was determined to be when the imaging plane was selected to be perpendicular to the implant axis. Moreover, the Mg-based implant outperformed the Ti equivalent in all experiments by producing lower metallic artefact (p < 0.05). This investigation demonstrates that Mg-based implants generate significantly lower metallic distortion in MRI when compared to Ti. Our positive findings suggest and support further research into the application of Mg-based implants including post-operative care facilitated by MRI monitoring of degradation kinetics and bone/tissue healing processes. Mg-based implants produce lower metallic artefact than Ti in MRI. Metallic artefact production of Mg reduces as degradation increases. Mg implants provide sufficient visualisation in MRI for better postoperative care.
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Affiliation(s)
| | - Mostafa Berangi
- MRI.TOOLS GmbH, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany.,Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | | | - Eduarda Silva
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Roberto Francischello
- Chemistry and Industrial Chemistry Department, Università di Pisa, Via Moruzzi 13, Pisa, Italy.,Fondazione Toscana Gabriele Monasterio, Via Moruzzi 1, Pisa, Italy
| | | | - Thoralf Niendorf
- MRI.TOOLS GmbH, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany.,Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sören Könneker
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
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Grieser T. Posttreatment Changes of the Elbow. Semin Musculoskelet Radiol 2022; 26:271-294. [PMID: 35654095 DOI: 10.1055/s-0042-1743402] [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
Radiologists should be familiar with the typical surgical procedures applied at the elbow and aware of the spectrum of normal and pathologic appearances of posttreatment situations throughout all radiologic modalities. Most important in the case of posttraumatic surgical elbow procedures is correct postoperative elbow joint alignment, appropriate fixation of joint-forming fragments, and proper insertion of screws, plates, and anchor devices that do not conflict with intra-articular or bony structures. To report soft tissue repair procedures correctly, radiologists need to know the broad spectrum of different techniques applied and their appearance on magnetic resonance imaging.
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Affiliation(s)
- Thomas Grieser
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Augsburg, Germany
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Abstract
It is around 20 years since the first commercial 3 T MRI systems became available. The theoretical promise of twice the signal-to-noise ratio of a 1.5 T system together with a greater sensitivity to magnetic susceptibility-related contrast mechanisms, such as the blood oxygen level dependent effect that is the basis for functional MRI, drove the initial market in neuroradiology. However, the limitations of the increased field strength soon became apparent, including the increased radiofrequency power deposition, tissue-dependent changes in relaxation times, increased artifacts, and greater safety concerns. Many of these issues are dependent upon MR physics and workarounds have had to be developed to try and mitigate their effects. This article reviews the underlying principles of the good, the bad and the ugly aspects of 3 T, discusses some of the methods used to improve image quality and explains the remaining challenges and concerns.
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Basic and Advanced Metal-Artifact Reduction Techniques at Ultra-High Field 7-T Magnetic Resonance Imaging-Phantom Study Investigating Feasibility and Efficacy. Invest Radiol 2022; 57:387-398. [PMID: 35025835 DOI: 10.1097/rli.0000000000000850] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The aim of this study was to demonstrate the feasibility and efficacy of basic (increased receive bandwidth) and advanced (view-angle tilting [VAT] and slice-encoding for metal artifact correction [SEMAC]) techniques for metal-artifact reduction in ultra-high field 7-T magnetic resonance imaging (MRI). MATERIALS AND METHODS In this experimental study, we performed 7-T MRI of titanium alloy phantom models composed of a spinal pedicle screw (phantom 1) and an intervertebral cage (phantom 2) centered in a rectangular LEGO frame, embedded in deionized-water-gadolinium (0.1 mmol/L) solution. The following turbo spin-echo sequences were acquired: (1) nonoptimized standard sequence; (2) optimized, that is, increased receive bandwidth sequence (oBW); (3) VAT; (4) combination of oBW and VAT (oBW-VAT); and (5) SEMAC. Two fellowship-trained musculoskeletal radiologists independently evaluated images regarding peri-implant signal void and geometric distortion (a, angle measurement and b, presence of circular shape loss). Statistics included Friedman test and Cochran Q test with Bonferroni correction for multiple comparisons. P values <0.05 were considered to represent statistical significance. RESULTS All metal-artifact reduction techniques reduced peri-implant signal voids and diminished geometric distortions, with oBW-VAT and SEMAC being most efficient. Compared with nonoptimized sequences, oBW-VAT and SEMAC produced significantly smaller peri-implant signal voids (all P ≤ 0.008) and significantly smaller distortion angles (P ≤ 0.001). Only SEMAC could significantly reduce distortions of circular shapes in the peri-implant frame (P ≤ 0.006). Notably, increasing the number of slice-encoding steps in SEMAC sequences did not lead to a significantly better metal-artifact reduction (all P ≥ 0.257). CONCLUSIONS The use of basic and advanced methods for metal-artifact reduction at 7-T MRI is feasible and effective. Both a combination of increased receive bandwidth and VAT as well as SEMAC significantly reduce the peri-implant signal void and geometric distortion around metal implants.
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Peschke E, Ulloa P, Jansen O, Hoevener JB. Metallic Implants in MRI - Hazards and Imaging Artifacts. ROFO-FORTSCHR RONTG 2021; 193:1285-1293. [PMID: 33979870 DOI: 10.1055/a-1460-8566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) is an examination method for noninvasive soft tissue imaging without the use of ionizing radiation. Metallic implants, however, may pose a risk for the patient and often result in imaging artifacts. Due to the increasing number of implants, reducing these artifacts has become an important goal. In this review, we describe the risks associated with implants and provide the background on how metal-induced artifacts are formed. We review the literature on methods on how to reduce artifacts and summarize our findings. METHOD The literature was searched using PubMed and the keywords "MRI metal artifact reduction", "metallic implants" and "MRI artefacts/artifacts". RESULTS AND CONCLUSION The MRI compatibility of implants has to be evaluated individually. To reduce artifacts, two general approaches were found: a) parameter optimization in standard sequences (echo time, slice thickness, bandwidth) and b) specialized sequences, such as VAT, OMAR, WARP, SEMAC and MAVRIC. These methods reduced artifacts and improved image quality, albeit at the cost of a (sometimes significantly) prolonged scan time. New developments in accelerated imaging will likely shorten the scan time of these methods significantly, such that routine use may become feasible. KEY POINTS · Metallic implants may pose a risk for patients and often cause artifacts.. · Imaging artifacts can be reduced by parameter optimization or special sequences.. · Metal artifacts are reduced with a lower TE, smaller voxel size, larger matrix, and higher bandwidth.. · SPI, STIR, VAT, SEMAC, MAVRIC, and MAVRIC-SL are specialized MR sequences that can reduce artifacts further.. CITATION FORMAT · Peschke E, Ulloa P, Jansen O et al. Metallic Implants in MRI - Hazards and Imaging Artifacts. Fortschr Röntgenstr 2021; 193: 1285 - 1293.
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Affiliation(s)
- Eva Peschke
- Department for Radiology and Neuroradiology, Molecular Imaging North Competence Center (MOIN CC), Section Biomedical Imaging, University Hospital Schleswig-Holstein - Campus Kiel, Kiel University, Germany
| | - Patricia Ulloa
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein - Campus Kiel, Germany
| | - Olav Jansen
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein - Campus Kiel, Germany
| | - Jan-Bernd Hoevener
- Department for Radiology and Neuroradiology, Molecular Imaging North Competence Center (MOIN CC), Section Biomedical Imaging, University Hospital Schleswig-Holstein - Campus Kiel, Kiel University, Germany
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Khodarahmi I, Kirsch J, Chang G, Fritz J. Metal artifacts of hip arthroplasty implants at 1.5-T and 3.0-T: a closer look into the B 1 effects. Skeletal Radiol 2021; 50:1007-1015. [PMID: 32918566 DOI: 10.1007/s00256-020-03597-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/27/2020] [Accepted: 08/30/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To evaluate the effect of circular polarization (CP) and elliptical polarization (EP) of the B1 field on metal implant-induced artifacts of titanium (Ti) and cobalt-chromium (CoCr) hip arthroplasty implants at 1.5-T and 3.0-T field strengths. MATERIAL AND METHODS In vitro Ti and CoCr total hip arthroplasty implants were evaluated using high transmit and receive bandwidth turbo spin echo (HBW-TSE) and slice encoding for metal artifact correction (SEMAC) metal artifact reduction techniques. Each technique was implemented at 1.5-T, which only allows for CP of B1 field as the system default, as well as 3.0-T, which permitted CP and EP. Manual segmentation quantified the size of the metal artifacts at the level of the acetabular cup, femoral neck, and femoral shaft. RESULTS In the acetabular cup and femoral neck, 1.5-T CP achieved smaller artifact sizes than 3.0-T CP (28-29% on HBW-TSE, p = 0.002-0.005; 17-34% on SEMAC, p = 0.019-0.102) and 3.0-T EP (25-28% on HBW-TSE, p = 0.010-0.011; 14-36% on SEMAC, p = 0.058-0.135) techniques. In the femoral stem region, 3.0-T EP achieved more efficient artifact suppression than 3.0-T CP (HBW-TSE 44-45%, p < 0.001-0.022; SEMAC 76-104%, p < 0.001-0.022) and 1.5-T CP (HBW-TSE 76-96%, p < 0.001-0.003; SEMAC 138-173%, p = 0.003-0.005) techniques. CONCLUSION Despite slightly superior metal reduction ability of the 1.5-T in the region of the acetabular cup and prosthesis neck, 3.0-T MRI of hip arthroplasty implants using elliptically polarized RF pulses may overall be more effective in reducing metal artifacts than the current standard 1.5-T MRI techniques, which by default implements circularly polarized RF pulses.
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Affiliation(s)
- Iman Khodarahmi
- Department of Radiology, New York University Grossman School of Medicine, 660 1st Ave, 3rd Floor, New York, NY, 10016, USA
| | - John Kirsch
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Gregory Chang
- Department of Radiology, New York University Grossman School of Medicine, 660 1st Ave, 3rd Floor, New York, NY, 10016, USA
| | - Jan Fritz
- Department of Radiology, New York University Grossman School of Medicine, 660 1st Ave, 3rd Floor, New York, NY, 10016, USA.
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Ouyang H, Han S, Jiang L, Zhuang H, Yang S, Liu Y, Zhang L, Liu X, Wei F, Chen K, Zhou S, Liu Z. Reossification and prognosis following radiotherapy with/without surgery for spinal solitary plasmacytoma of the bone: a retrospective study of 39 patients. Spine J 2020; 20:283-291. [PMID: 31546017 DOI: 10.1016/j.spinee.2019.09.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Solitary plasmacytoma of bone (SPB) can progress to multiple myeloma (MM). Little attention has been paid to the reossification findings on computed tomography (CT) and their correlation with prognosis after radiotherapy with/without surgery. PURPOSE To evaluate reossification after radiotherapy and prognostic factors of spinal SPB using single-center data. STUDY DESIGN Retrospective observational study. PATIENT SAMPLE Patients who had spinal SPB and received radiotherapy with/without surgery, without chemotherapy, denosumab or zoledronic acid. OUTCOME MEASURES MM progression rate, mortality rate, and reossification rate at 12 months. METHODS This retrospective clinical review included 39 patients who underwent radiotherapy as first-line treatment for SPB in the spine. External radiation was divided into 20-25 fractions with a total dose of 35-46 Gy. At the 12-month follow-up after the index radiotherapy, significant and mild reossification, defined as bone formation with ≥30% or 0%-30% increase, respectively, in bony area based on increase in CT values were documented, along with progressive disease, which was a decrease in bony area with lesion enlargement. This study was funded by AO Foundation, AOSpine (AOSDIA2019-026) (CHF45,000), Peking University Medicine Seed Fund for Interdisciplinary Research (BMU2018MX022) (¥40,000), and Peking University Third Hospital (No. Y71508-01) (¥400,000). RESULTS Twenty-six men and 13 women (mean age, 51.5 years) were included. Solitary plasmacytomas were located in the cervical, thoracic, and lumbar vertebrae in 16, 17, and 6 patients, respectively. The mean clinical follow-up period after treatment was 72 (range 12-216) months. Sixteen patients (41.0%) had significant reossification after radiotherapy, 21 (53.8%) showed mild reossification, and 2 (5.2%) had progressive bony destruction (after 7 and 23 months, respectively). There were no significant differences in age among the three groups (p=.127). At a mean follow-up of 37 (range 6-90) months after radiosurgery, 14 (35.8%) patients developed MM, including 9 patients who died at a mean duration of 55 (range 19-102) months. In the significant reossification group, only 1 patient (6.3%, 1 of 16) had MM progression 82 months after treatment (p=.044). In the mild reossification group, 56.5% (13 of 23) of patients had MM progression. The significant reossification rates of the radiotherapy dose groups of <40 Gy and ≥40 Gy were 35.7% and 44% (p=.614), respectively. In the univariate analysis, age ≥65 years (p<.001), tumor ≥5 cm (p=.009), Spinal Instability Neoplastic Score scores ≥11.5 (p=.040), radiotherapy (RT) combined with surgery (p<.001), and progression to MM (p=.007) were the independent prognostic factors for overall survival; whereas, age >44 years (p=.045) and RT combined with surgery (p<.001) were for multiple myeloma-free survival. In the multivariate analyses, age >65 years (p=.004) and progression to MM (p=.007) were the unfavorable independent factors for overall survival, whereas RT combined with surgery (p=.004) was the only factor for multiple myeloma-free survival. CONCLUSIONS In patients with spinal SPB, 41.0% lesions showed significant reossification after radiotherapy. Patients with significant reossification had a better prognosis with less possibility of MM progression. Radiotherapy may be a safe and effective treatment choice for spinal SPB; more attention should be paid to reossification.
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Affiliation(s)
- Hanqiang Ouyang
- Department of Orthopedic, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing 100191, China
| | - Songbo Han
- Department of Radiology, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing, 100191, China
| | - Liang Jiang
- Department of Orthopedic, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing 100191, China.
| | - Hongqing Zhuang
- Department of Radiotherapy, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing, 100191, China
| | - Shaomin Yang
- Department of Pathology, Peking University Health Center, No. 38 Xueyuan Rd, Haidian District, Beijing, 100191, China
| | - Yan Liu
- Department of Hematology, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing, 100191, China
| | - Lihua Zhang
- Department of Radiology, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing, 100191, China
| | - Xiaoguang Liu
- Department of Orthopedic, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing 100191, China
| | - Feng Wei
- Department of Orthopedic, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing 100191, China
| | - Keyuan Chen
- Department of Orthopedic, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing 100191, China; Peking University Health and Science Center, No. 38 Xueyuan Rd, Haidian District, Beijing, 100191, China
| | - Siyu Zhou
- Department of Orthopedic, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing 100191, China; Peking University Health and Science Center, No. 38 Xueyuan Rd, Haidian District, Beijing, 100191, China
| | - Zhongjun Liu
- Department of Orthopedic, Peking University Third Hospital, No. 49 North Garden Rd, Haidian District, Beijing 100191, China
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Tang M, Kawahira S, Nomura N, Yamamoto T. Torque property of titanium alloy cerebral aneurysm clips in a magnetic resonance scanner. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2019; 31:6. [PMID: 31838592 DOI: 10.1007/s10856-019-6329-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 11/16/2019] [Indexed: 05/21/2023]
Abstract
Titanium (Ti) alloys have been introduced in magnetic resonance (MR) safe implantable medical devices because the susceptibility of Ti is approximately 1/10 that of the Co-Cr-Ni alloy (Elgiloy), which was the previously preferred MR-safe material. The torque applied to metallic materials in an MR imaging (MRI) scanner is commonly believed to increase with the susceptibility of the material. However, a visual inspection showed that the torque applied to Ti alloy cerebral aneurysm clips is comparable with that in the case of those of Elgiloy. In this study, we measured the torque applied to the small test pieces of rods and aneurysm clips quantitatively in a 3-T MRI using an accurate self-developed torque measurement apparatus. The maximum torques of Ti alloy and Elgiloy rod test pieces were comparable as 1.1 and 1.2 µN·m, respectively. The values for Ti alloy aneurysm clips were distinctly higher than the values for those of Elgiloy. These contradictory results of a larger torque for smaller-susceptibility products could be explained by our new theory, which takes into account the crystal susceptibility anisotropy in addition to the conventional torque due to the shape anisotropy.
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Affiliation(s)
- Minghui Tang
- Division of Biomedical Engineering and Science, Faculty of Health Sciences, Hokkaido University, Sapporo, 060-0812, Japan
| | - Shingo Kawahira
- Department of Medical Radiation Technology, Sapporo Nishi Maruyama Hospital, Sapporo, 064-8557, Japan
| | - Naoyuki Nomura
- Department of Metallurgy, Materials Science and Materials Processing, Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan
| | - Toru Yamamoto
- Division of Biomedical Engineering and Science, Faculty of Health Sciences, Hokkaido University, Sapporo, 060-0812, Japan.
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12
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Seo S, Do W, Luu HM, Kim KH, Choi SH, Park S. Artificial neural network for Slice Encoding for Metal Artifact Correction (SEMAC) MRI. Magn Reson Med 2019; 84:263-276. [DOI: 10.1002/mrm.28126] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 11/21/2019] [Accepted: 11/21/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Sunghun Seo
- Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology Daejeon Korea
| | - Won‐Joon Do
- Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology Daejeon Korea
| | - Huan Minh Luu
- Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology Daejeon Korea
| | - Ki Hwan Kim
- Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology Daejeon Korea
| | - Seung Hong Choi
- Department of Radiology Seoul National University College of Medicine Seoul Korea
| | - Sung‐Hong Park
- Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology Daejeon Korea
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13
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Usefulness of slice encoding for metal artifact correction (SEMAC) technique for reducing metal artifacts after total knee arthroplasty. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY 2018; 29:659-666. [PMID: 30310989 DOI: 10.1007/s00590-018-2322-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 09/19/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE To evaluate the usefulness of a novel MRI sequence strategy in the assessment of the periprosthetic anatomical structures after primary total knee arthroplasty. METHODS Two MR sequences were retrospectively compared for the imaging of 15 patients with implanted cruciate-retaining/fixed-bearing TKAs (DePuy, PFC Sigma): a slice encoding sequence for metal artifact correction (SEMAC) and a standard sequence. Images were acquired on a 1.5-T system. The degree of artifact reduction was assessed using several qualitative (Likert-type scale) (artifact size, distorsion, blur, image quality, periprosthetic bone, posterior cruciate ligament, lateral collateral ligament, medial collateral ligament, patella tendon, popliteal vessels) and quantitative (artifact volume, Insall-Salvati index, length of patella/tendon, prosthesis dimensions) parameters by blinded reads performed by four investigators. The SEMAC sequences were statistically compared with the standard sequence using Wilcoxon test. Additionally, the intraclass correlation coefficient (ICC) for interobserver agreement was calculated. RESULTS Higher levels of blurring were found with SEMAC compared to standard sequences (p < 0.001). All other qualitative parameters improved significantly with the application of SEMAC. In comparison with conventional sequences, the artifact volume was reduced by 59% utilizing SEMAC. Thus, the artifact reduction improved the precision of measurements such as Insall-Salvati index and length of patella/tendon (p < 0.001). The dimension of the tibial component (Ti alloy/polyethylene) revealed accurate values with both MRI sequences. A sufficient interobserver agreement among all readers was found with SEMAC, qualitatively ICC 0.9 (range 0.8-1) as well as quantitatively ICC 0.95 (range 0.92-0.98). CONCLUSIONS SEMAC effectively reduces artifacts caused by metallic implants after total knee arthroplasty relative to standard imaging. This allows for an improved assessment of periprosthetic anatomical structures. This might enable an improved detectability of postoperative complications in the future. LEVEL OF EVIDENCE Diagnostic Study Level III.
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14
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Histogram analysis of apparent diffusion coefficient maps in the prognosis of patients with locally advanced head and neck squamous cell carcinoma: Comparison of different region of interest selection methods. Eur J Radiol 2018; 106:7-13. [DOI: 10.1016/j.ejrad.2018.07.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/24/2018] [Accepted: 07/03/2018] [Indexed: 11/23/2022]
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15
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Cho WS, Cho KI, Kim JE, Jang TS, Ha EJ, Kang HS, Son YJ, Choi SH, Lee S, Kim CC, Sun JY, Kim HE. Zirconia-Polyurethane Aneurysm Clip. World Neurosurg 2018; 115:14-23. [DOI: 10.1016/j.wneu.2018.03.130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/18/2018] [Accepted: 03/19/2018] [Indexed: 10/17/2022]
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16
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Rendenbach C, Schoellchen M, Bueschel J, Gauer T, Sedlacik J, Kutzner D, Vallittu PK, Heiland M, Smeets R, Fiehler J, Siemonsen S. Evaluation and reduction of magnetic resonance imaging artefacts induced by distinct plates for osseous fixation: an in vitro study @ 3 T. Dentomaxillofac Radiol 2018; 47:20170361. [PMID: 29718688 DOI: 10.1259/dmfr.20170361] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVES: To analyze MRI artefacts induced at 3 T by bioresorbable, titanium (TI) and glass fibre reinforced composite (GFRC) plates for osseous reconstruction. METHODS: Fixation plates including bioresorbable polymers (Inion CPS, Inion Oy, Tampere, Finland; Rapidsorb, DePuy Synthes, Umkirch, Germany; Resorb X, Gebrueder KLS Martin GmbH, Tuttlingen, Germany), GFRC (Skulle Implants Oy, Turku, Finland) and TI plates of varying thickness and design (DePuy Synthes, Umkirch, Germany) were embedded in agarose gel and a 3 T MRI was performed using a standard protocol for head and neck imaging including T1W and T2W sequences. Additionally, different artefact reduction techniques (slice encoding for metal artefact reduction & ultrashort echo time) were used and their impact on the extent of artefacts evaluated for each material. RESULTS: All TI plates induced significantly more artefacts than resorbable plates in T1W and T2W sequences. GFRCs induced the least artefacts in both sequences. The total extent of artefacts increased with plate thickness and height. Plate thickness had no influence on the percentage of overestimation in all three dimensions. TI-induced artefacts were significantly reduced by both artefact reduction techniques. CONCLUSIONS: Polylactide, GFRC and magnesium plates produce less susceptibility artefacts in MRI compared to TI, while the dimensions of TI plates directly influence artefact extension. Slice encoding for metal artefact reduction and ultrashort echo time significantly reduce metal artefacts at the expense of scan time or image resolution.
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Affiliation(s)
- Carsten Rendenbach
- 1 Department of Oral and Maxillofacial Surgery, Charité - Universitaetsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health , Berlin , Germany.,2 Berlin Institute of Health (BIH) , Berlin , Germany
| | - Max Schoellchen
- 3 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Julie Bueschel
- 3 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Tobias Gauer
- 4 Department of Radiotherapy and Radiation Oncology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Jan Sedlacik
- 5 Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Daniel Kutzner
- 5 Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Pekka K Vallittu
- 6 Department of Biomaterials Science, Institute of Dentistry, University of Turku, and City of Turku, Welfare Division , Turku , Finland
| | - Max Heiland
- 1 Department of Oral and Maxillofacial Surgery, Charité - Universitaetsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health , Berlin , Germany
| | - Ralf Smeets
- 3 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Jens Fiehler
- 5 Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Susanne Siemonsen
- 5 Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
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17
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MRI artefact in the rectum caused by ingested orthodontic brackets. Radiography (Lond) 2018; 24:e48-e50. [PMID: 29605125 DOI: 10.1016/j.radi.2017.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/08/2017] [Accepted: 10/12/2017] [Indexed: 11/23/2022]
Abstract
Magnetic susceptibility artefacts, caused by metallic objects, present a challenge in magnetic resonance imaging (MRI). In this case, MRI showed metal-induced artefact in the rectum of a 14-year-old girl who presented with pain in the coccyx after a snowboarding accident. Previous radiographs showed no evidence of metal in the area. After the identification of the artefact and upon discussion with the patient, she disclosed that two orthodontic brackets had been swallowed two days prior to the MRI examination, likely the source of artefact. Following the passage of the brackets, subsequent MRI was artefact-free. A similar artefact was recreated by scanning a potato with and without an orthodontic bracket, highlighting the impact of the resulting artefact on MRI.
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18
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Filli L, Jud L, Luechinger R, Nanz D, Andreisek G, Runge VM, Kozerke S, Farshad-Amacker NA. Material-Dependent Implant Artifact Reduction Using SEMAC-VAT and MAVRIC: A Prospective MRI Phantom Study. Invest Radiol 2018; 52:381-387. [PMID: 28092272 DOI: 10.1097/rli.0000000000000351] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of this study was to compare the degree of artifact reduction in magnetic resonance imaging achieved with slice encoding for metal artifact correction (SEMAC) in combination with view angle tilting (VAT) and multiacquisition variable resonance image combination (MAVRIC) for standard contrast weightings and different metallic materials. METHODS Four identically shaped rods made of the most commonly used prosthetic materials (stainless steel, SS; titanium, Ti; cobalt-chromium-molybdenum, CoCr; and oxidized zirconium, oxZi) were scanned at 3 T. In addition to conventional fast spin-echo sequences, metal artifact reduction sequences (SEMAC-VAT and MAVRIC) with varying degrees of artifact suppression were applied at different contrast weightings (T1w, T2w, PDw). Two independent readers measured in-plane and through-plane artifacts in a standardized manner. In addition, theoretical frequency-offset and frequency-offset-gradient maps were calculated. Interobserver agreement was assessed using intraclass correlation coefficient. RESULTS Interobserver agreement was almost perfect (intraclass correlation coefficient, 0.86-0.99). Stainless steel caused the greatest artifacts, followed by CoCr, Ti, and oxZi regardless of the imaging sequence. While for Ti and oxZi rods scanning with weak SEMAC-VAT showed some advantage, for SS and CoCr, higher modes of SEMAC-VAT or MAVRIC were necessary to achieve artifact reduction. MAVRIC achieved better artifact reduction than SEMAC-VAT at the cost of longer acquisition times. Simulations matched well with the apparent geometry of the frequency-offset maps. CONCLUSIONS For Ti and oxZi implants, weak SEMAC-VAT may be preferred as it is faster and produces less artifact than conventional fast spin-echo. Medium or strong SEMAC-VAT or MAVRIC modes are necessary for significant artifact reduction for SS and CoCr implants. KEY POINTS
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Affiliation(s)
- Lukas Filli
- From the *Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich; †Institute for Biomedical Engineering, University and ETH Zurich, Zurich; ‡Department of Radiology, Kantonsspital Muensterlingen, Muensterlingen; §University of Zurich, Zurich; and ∥Department of Radiology, Hospital and University of Bern, Inselspital, Bern, Switzerland
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19
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Abstract
Over the past decade, the application of magnetic resonance imaging (MRI) has increased, and there is growing evidence to suggest that improvements in the accuracy of target delineation in MRI-guided radiation therapy may improve clinical outcomes in a variety of cancer types. However, some considerations should be recognized including patient motion during image acquisition and geometric accuracy of images. Moreover, MR-compatible immobilization devices need to be used when acquiring images in the treatment position while minimizing patient motion during the scan time. Finally, synthetic CT images (i.e. electron density maps) and digitally reconstructed radiograph images should be generated from MRI images for dose calculation and image guidance prior to treatment. A short review of the concepts and techniques that have been developed for implementation of MRI-only workflows in radiation therapy is provided in this document.
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Affiliation(s)
- Amir M. Owrangi
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas
| | - Peter B. Greer
- School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, NSW, 2308, Australia
- Department of Radiation Oncology, Calvary Mater Hospital, Newcastle, NSW, 2298, Australia
| | - Carri K. Glide-Hurst
- Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan
- Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan
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20
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Jungmann PM, Agten CA, Pfirrmann CW, Sutter R. Advances in MRI around metal. J Magn Reson Imaging 2017; 46:972-991. [PMID: 28342291 DOI: 10.1002/jmri.25708] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 03/03/2017] [Indexed: 01/02/2023] Open
Abstract
The prevalence of orthopedic metal implants is continuously rising in the aging society. Particularly the number of joint replacements is increasing. Although satisfying long-term results are encountered, patients may suffer from complaints or complications during follow-up, and often undergo magnetic resonance imaging (MRI). Yet metal implants cause severe artifacts on MRI, resulting in signal-loss, signal-pileup, geometric distortion, and failure of fat suppression. In order to allow for adequate treatment decisions, metal artifact reduction sequences (MARS) are essential for proper radiological evaluation of postoperative findings in these patients. During recent years, developments of musculoskeletal imaging have addressed this particular technical challenge of postoperative MRI around metal. Besides implant material composition, configuration and location, selection of appropriate MRI hardware, sequences, and parameters influence artifact genesis and reduction. Application of dedicated metal artifact reduction techniques including high bandwidth optimization, view angle tilting (VAT), and the multispectral imaging techniques multiacquisition variable-resonance image combination (MAVRIC) and slice-encoding for metal artifact correction (SEMAC) may significantly reduce metal-induced artifacts, although at the expense of signal-to-noise ratio and/or acquisition time. Adding advanced image acquisition techniques such as parallel imaging, partial Fourier transformation, and advanced reconstruction techniques such as compressed sensing further improves MARS imaging in a clinically feasible scan time. This review focuses on current clinically applicable MARS techniques. Understanding of the main principles and techniques including their limitations allows a considerate application of these techniques in clinical practice. Essential orthopedic metal implants and postoperative MR findings around metal are presented and highlighted with clinical examples. LEVEL OF EVIDENCE 4 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:972-991.
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Affiliation(s)
- Pia M Jungmann
- Department of Radiology, Balgrist University Hospital, Zurich, Switzerland.,Faculty of Medicine, University of Zurich, Zurich, Switzerland.,Department of Radiology, Technical University of Munich, Munich, Germany
| | - Christoph A Agten
- Department of Radiology, Balgrist University Hospital, Zurich, Switzerland.,Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | - Christian W Pfirrmann
- Department of Radiology, Balgrist University Hospital, Zurich, Switzerland.,Department of Radiology, Technical University of Munich, Munich, Germany
| | - Reto Sutter
- Department of Radiology, Balgrist University Hospital, Zurich, Switzerland.,Department of Radiology, Technical University of Munich, Munich, Germany
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21
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Rao YJ, Zoberi JE, Kadbi M, Grigsby PW, Cammin J, Mackey SL, Garcia-Ramirez J, Goddu SM, Schwarz JK, Gach HM. Metal artifact reduction in MRI-based cervical cancer intracavitary brachytherapy. Phys Med Biol 2017; 62:3011-3024. [DOI: 10.1088/1361-6560/62/8/3011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Ahmad SB, Sarfehnia A, Kim A, Wronski M, Sahgal A, Keller BM. Backscatter dose effects for high atomic number materials being irradiated in the presence of a magnetic field: A Monte Carlo study for the MRI linac. Med Phys 2017; 43:4665. [PMID: 27487883 DOI: 10.1118/1.4955175] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To quantify and explain the backscatter dose effects for clinically relevant high atomic number materials being irradiated in the presence of a 1.5 T transverse magnetic field. METHODS Interface effects were investigated using Monte Carlo simulation techniques. We used gpumcd (v5.1) and geant4 (v10.1) for this purpose. gpumcd is a commercial software written for the Elekta AB, MRI linac. Dose was scored using gpumcd in cubic voxels of side 1 and 0.5 mm, in two different virtual phantoms of dimensions 20 × 20 × 20 cm and 5 × 5 × 13.3 cm, respectively. A photon beam was generated from a point 143.5 cm away from the isocenter with energy distribution sampled from a histogram representing the true Elekta, MRI linac photon spectrum. A slab of variable thickness and position containing either bone, aluminum, titanium, stainless steel, or one of the two different dental filling materials was inserted as an inhomogeneity in the 20 × 20 × 20 cm phantom. The 5 × 5 × 13.3 cm phantom was used as a clinical test case in order to explain the dose perturbation effects for a head and neck cancer patient. The back scatter dose factor (BSDF) was defined as the ratio of the doses at a given depth with and without the presence of the inhomogeneity. Backscattered electron fluence was calculated at the inhomogeneity interface using geant4. A 1.5 T magnetic field was applied perpendicular to the direction of the beam in both phantoms, identical to the geometry in the Elekta MRI linac. RESULTS With the application of a 1.5 T magnetic field, all the BSDF's were reduced by 12%-47%, compared to the no magnetic field case. The corresponding backscattered electron fluence at the interface was also reduced by 45%-64%. The reduction in the BSDF at the interface, due to the application of the magnetic field, is manifested in a different manner for each material. In the case of bone, the dose drops at the interface contrary to the expected increase when no magnetic field is applied. In the case of aluminum, the dose at the interface is the same with and without the presence of the aluminum. For all of the other materials the dose increases at the interface. CONCLUSIONS The reduction in dose at the interface, in the presence of the magnetic field, is directly related to the reduction in backscattered electron fluence. This reduction occurs due to two different reasons. First, the electron spectrum hitting the interface is changed when the magnetic field is turned on, which results in changes in the electron scattering probability. Second, some electrons that have curved trajectories due to the presence of the magnetic field are absorbed by the higher density side of the interface and no longer contribute to the backscattered electron fluence.
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Affiliation(s)
- Syed Bilal Ahmad
- Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada and Sunnybrook Health Sciences Center, Odette Cancer Center, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
| | - Arman Sarfehnia
- Sunnybrook Health Sciences Center, Odette Cancer Center, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S 1A1, Canada
| | - Anthony Kim
- Sunnybrook Health Sciences Center, Odette Cancer Center, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S 1A1, Canada
| | - Matt Wronski
- Sunnybrook Health Sciences Center, Odette Cancer Center, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S 1A1, Canada
| | - Arjun Sahgal
- Sunnybrook Health Sciences Center, Odette Cancer Center, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S 1A1, Canada
| | - Brian M Keller
- Sunnybrook Health Sciences Center, Odette Cancer Center, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, University of Toronto, 27 King's College Circle, Toronto, Ontario M5S 1A1, Canada
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Schmidt MA, Panek R, Colgan R, Hughes J, Sohaib A, Saran F, Murray J, Bernard J, Revell P, Nittka M, Leach MO, Hansen VN. Slice Encoding for Metal Artefact Correction in magnetic resonance imaging examinations for radiotherapy planning. Radiother Oncol 2016; 120:356-62. [PMID: 27222296 PMCID: PMC5013753 DOI: 10.1016/j.radonc.2016.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 04/27/2016] [Accepted: 05/05/2016] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Magnetic resonance (MR) and computed tomography (CT) images are degraded in the presence of metallic implants. We investigate whether SEMAC (Slice Encoding for Metal Artifact Correction) MR is advantageous for radiotherapy (RT) planning. METHODS Conventional and SEMAC MR protocols were compared (1.5T). A spine fixation device suspended in gelatine, two patients with spine fixation devices and six patients with bilateral hip replacements were scanned with both conventional and SEMAC protocols. In spine patients the visibility of the spinal canal and spinal cord was assessed; in prostate patients, the visibility of the prostate, pelvic structures and the pelvic girdle. RESULTS The signal loss volume surrounding the spine fixation device was reduced by approximately 20% when the SEMAC protocol was employed, and registration errors were reduced. For spine patients, the spinal canal was completely visible only using the SEMAC protocol. In hip replacement patients, metal artifacts were local; the signal loss extended to the internal surface of the acetabulum in eight implants with conventional protocols, but only in four using SEMAC. CONCLUSIONS SEMAC MR contributes towards correct co-registration of MR and CT images for RT planning, and is particularly relevant when the TV or OARs are close to implants.
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Affiliation(s)
- Maria A Schmidt
- The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, CR-UK & EPSRC Cancer Imaging Centre, Sutton, United Kingdom.
| | - Rafal Panek
- The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, CR-UK & EPSRC Cancer Imaging Centre, Sutton, United Kingdom
| | - Ruth Colgan
- Royal Marsden NHS Foundation Trust, Radiotherapy Department, Sutton, United Kingdom
| | - Julie Hughes
- Royal Marsden NHS Foundation Trust, Radiology Department, Sutton, United Kingdom
| | - Aslam Sohaib
- Royal Marsden NHS Foundation Trust, Radiology Department, Sutton, United Kingdom
| | - Frank Saran
- Royal Marsden NHS Foundation Trust, Neuro-Oncology Unit, Sutton, United Kingdom
| | - Julia Murray
- Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Radiotherapy and Imaging Department, Sutton, United Kingdom
| | - Jason Bernard
- St George's Hospital NHS Trust, Orthopaedic Surgery, London, United Kingdom
| | - Patrick Revell
- Siemens Healthcare GmbH, Diagnostic Imaging, Camberley, United Kingdom
| | - Mathias Nittka
- Siemens Healthcare Limited, Diagnostic Imaging, Erlangen, Germany
| | - Martin O Leach
- The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, CR-UK & EPSRC Cancer Imaging Centre, Sutton, United Kingdom
| | - Vibeke N Hansen
- Royal Marsden NHS Foundation Trust, Radiotherapy Department, Sutton, United Kingdom
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Preda L, Conte G, Bonello L, Giannitto C, Travaini LL, Raimondi S, Summers PE, Mohssen A, Alterio D, Cossu Rocca M, Grana C, Ruju F, Bellomi M. Combining standardized uptake value of FDG-PET and apparent diffusion coefficient of DW-MRI improves risk stratification in head and neck squamous cell carcinoma. Eur Radiol 2016; 26:4432-4441. [PMID: 26965504 DOI: 10.1007/s00330-016-4284-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/30/2015] [Accepted: 02/16/2016] [Indexed: 12/20/2022]
Abstract
OBJECTIVES To assess the independent prognostic value of standardized uptake value (SUV) and apparent diffusion coefficient (ADC), separately and combined, in order to evaluate if the combination of these two variables allows further prognostic stratification of patients with head and neck squamous cell carcinomas (HNSCC). METHODS Pretreatment SUV and ADC were calculated in 57 patients with HNSCC. Mean follow-up was 21.3 months. Semiquantitative analysis of primary tumours was performed using SUVmaxT/B, ADCmean, ADCmin and ADCmax. The prognostic value of SUVmaxT/B, ADCmean, ADCmin and ADCmax in predicting disease-free survival (DFS) was evaluated with log-rank test and Cox regression models. RESULTS Patients with SUVmaxT/B ≥5.75 had an overall worse prognosis (p = 0.003). After adjusting for lymph node status and diameter, SUVmaxT/B and ADCmin were both significant predictors of DFS with hazard ratio (HR) = 10.37 (95 % CI 1.22-87.95) and 3.26 (95 % CI 1.20-8.85) for SUVmaxT/B ≥5.75 and ADCmin ≥0.58 × 10-3 mm2/s, respectively. When the analysis was restricted to subjects with SUVmaxT/B ≥5.75, high ADCmin significantly predicted a worse prognosis, with adjusted HR = 3.11 (95 % CI 1.13-8.55). CONCLUSIONS The combination of SUVmaxT/B and ADCmin improves the prognostic role of the two separate parameters; patients with high SUVmaxT/B and high ADCmin are associated with a poor prognosis. KEY POINTS • High SUV maxT/B is a poor prognostic factor in HNSCC • High ADC min is a poor prognostic factor in HNSCC • In patients with high SUV maxT/B , high ADC min identified those with worse prognosis.
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Affiliation(s)
- Lorenzo Preda
- Department of Radiology, European Institute of Oncology, Milan, Italy
| | - Giorgio Conte
- Specialisation School of Radiology, University of Milan, Milan, Italy.
| | - Luke Bonello
- Specialisation School of Radiology, University of Milan, Milan, Italy
| | | | - Laura L Travaini
- Department of Nuclear Medicine, European Institute of Oncology, Milan, Italy
| | - Sara Raimondi
- Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy
| | - Paul E Summers
- Department of Radiology, European Institute of Oncology, Milan, Italy
| | - Ansarin Mohssen
- Department of Head and Neck Surgery, European Institute of Oncology, Milan, Italy
| | - Daniela Alterio
- Department of Radiotherapy, European Institute of Oncology, Milan, Italy
| | - Maria Cossu Rocca
- Department of Urogenital Cancer Medical Treatment, European Institute of Oncology, Milan, Italy
| | - Chiara Grana
- Department of Nuclear Medicine, European Institute of Oncology, Milan, Italy
| | - Francesca Ruju
- Specialisation School of Radiology, University of Milan, Milan, Italy
| | - Massimo Bellomi
- Department of Radiology, European Institute of Oncology, Milan, Italy.,Department of Oncology and Haematology-Oncology, University of Milan, Milan, Italy
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25
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Falcinelli L, Palumbo I, Radicchia V, Arcidiacono F, Lancellotta V, Montesi G, Matrone F, Zucchetti C, Marcantonini M, Bini V, Aristei C. Prostate cancer: contouring target and organs at risk by kilovoltage and megavoltage CT and MRI in patients with and without hip prostheses. Br J Radiol 2015; 88:20150509. [PMID: 26462970 DOI: 10.1259/bjr.20150509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE In radiotherapy treatment, planning target volume and organs at risk are contoured on kilovoltage CT (kVCT) images. Unlike MR images, kVCT does not provide precise information on target volume extension. Since neither kVCT nor MRI may be suitable for contouring in patients with ferrous hip prostheses, this study evaluated whether megavoltage CT (MVCT) reduced interobserver variability. METHODS Two patients without hip prostheses and one patient (Patient 3) with hip prostheses were enrolled. Six radiation oncologists contoured prostate, rectum and bladder on kVCT (Patients 1 and 3), MRI (Patient 2) and MVCT images (Patient 3). MVCT was acquired with fine, normal and coarse modalities. Interobserver variability for each organ was analysed using conformity index (CI) and coefficient of variation (CV). RESULTS In patients without hip prostheses, CIs were higher in prostate contouring with MRI than with kVCT, indicating lower interobserver variability with MRI. Very slight variations were seen in rectum and bladder contouring. In the patient with hip prostheses (Patient 3), contouring on kVCT lowered CI and increased CV in the prostate, bladder and rectum. The differences were more marked in the prostate. Only fine modality MVCT reduced interobserver variability and only for the prostate. CONCLUSION Even though greater noise and less soft-tissue contrast increase contouring variability with MVCT than with kVCT, lack of artefacts on MVCT could provide better image definition by this modality in hip prosthesis patients in whom MRI is precluded. ADVANCES IN KNOWLEDGE We recommend the fine modality MVCT for contouring hip prostheses patients.
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Affiliation(s)
- Lorenzo Falcinelli
- 1 Department of Onco-Haematological and Gastroenterological Science, Radiation Oncology Division, Perugia General Hospital, Perugia, Italy
| | - Isabella Palumbo
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Valentina Radicchia
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Fabio Arcidiacono
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Valentina Lancellotta
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Giampaolo Montesi
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Fabio Matrone
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Claudio Zucchetti
- 3 Department of Imaging and Laboratory Diagnosis, Medical Physics Unit, Perugia General Hospital, Perugia, Italy
| | - Marta Marcantonini
- 3 Department of Imaging and Laboratory Diagnosis, Medical Physics Unit, Perugia General Hospital, Perugia, Italy
| | - Vittorio Bini
- 4 Internal Medicine, Endocrine and Metabolic Sciences Section, Perugia General Hospital, Perugia, Italy
| | - Cynthia Aristei
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
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26
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McGee KP, Hu Y, Tryggestad E, Brinkmann D, Witte B, Welker K, Panda A, Haddock M, Bernstein MA. MRI in radiation oncology: Underserved needs. Magn Reson Med 2015; 75:11-4. [PMID: 26173404 DOI: 10.1002/mrm.25826] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 06/09/2015] [Indexed: 12/12/2022]
Affiliation(s)
- Kiaran P McGee
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Yanle Hu
- Department of Radiation Oncology, Mayo Clinic, Scottsdale, Arizona, USA
| | - Erik Tryggestad
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Debra Brinkmann
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Bob Witte
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Kirk Welker
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Anshuman Panda
- Department of Radiology, Mayo Clinic, Scottsdale, Arizona, USA
| | - Michael Haddock
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
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