1
|
Akerman M, Sneag DB, Gfrerer L, Endo Y, Valenti AB, Clements IP, Tan ET. MRI and Ultrasound Visualization of a Nerve Repair Implant Containing Nitinol. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2024; 12:e6063. [PMID: 39129845 PMCID: PMC11315573 DOI: 10.1097/gox.0000000000006063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 06/21/2024] [Indexed: 08/13/2024]
Abstract
Background Nerve Tape is a novel nerve repair device containing nitinol microhooks that provide sutureless attachment for nerve coaptation. This study evaluated visualization of Nerve Tape on magnetic resonance imaging (MRI) and ultrasound, with the objective of exploring its potential as an imaging marker for localizing nerve repair sites. Methods Phantom imaging experiments were first conducted to assess the visibility of Nerve Tape on MRI and ultrasound. A cadaveric limb investigation was then performed to further characterize the magnetic susceptibility patterns of Nerve Tape and to confirm its localization at the repair site. Results Phantom imaging experiments demonstrated clear visualization of Nerve Tape on both MRI and ultrasound, with Nerve Tape microhooks appearing as signal voids on MRI and hyperechoic foci on ultrasound. Subsequent cadaveric limb investigation further characterized Nerve Tape's magnetic susceptibility patterns and confirmed localization of the device at the repair site. The physical dimensions of Nerve Tape and locations observed on both MRI and ultrasound matched design and measurements made during surgery. Measurement discrepancies could be attributed to magnetic susceptibility artifacts in MRI, and to comet tail and shadowing effects in ultrasound. Conclusions Repairs performed with Nerve Tape can be reliably localized for imaging, potentially facilitating assessment of repair site integrity and further advancement toward image-based monitoring of nerve regeneration. Further research, including in vivo human studies, is warranted to confirm these preliminary findings.
Collapse
Affiliation(s)
- Michelle Akerman
- From the Radiology and Imaging, Hospital for Special Surgery, New York, N.Y
| | - Darryl B. Sneag
- From the Radiology and Imaging, Hospital for Special Surgery, New York, N.Y
| | - Lisa Gfrerer
- Plastic and Reconstructive Surgery, Weill Cornell Medicine, New York, N.Y
| | - Yoshimi Endo
- From the Radiology and Imaging, Hospital for Special Surgery, New York, N.Y
| | - Alyssa B. Valenti
- Plastic and Reconstructive Surgery, Weill Cornell Medicine, New York, N.Y
| | | | - Ek T. Tan
- From the Radiology and Imaging, Hospital for Special Surgery, New York, N.Y
| |
Collapse
|
2
|
Spronk T, Kraff O, Schaefers G, Quick HH. Numerical approach to investigate MR imaging artifacts from orthopedic implants at different field strengths according to ASTM F2119. MAGMA (NEW YORK, N.Y.) 2023; 36:725-735. [PMID: 36933090 PMCID: PMC10504103 DOI: 10.1007/s10334-023-01074-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 02/24/2023] [Accepted: 02/26/2023] [Indexed: 03/19/2023]
Abstract
OBJECTIVE This study presents an extended evaluation of a numerical approach to simulate artifacts of metallic implants in an MR environment. METHODS The numerical approach is validated by comparing the artifact shape of the simulations and measurements of two metallic orthopedic implants at three different field strengths (1.5 T, 3 T, and 7 T). Furthermore, this study presents three additional use cases of the numerical simulation. The first one shows how numerical simulations can improve the artifact size evaluation according to ASTM F2119. The second use case quantifies the influence of different imaging parameters (TE and bandwidth) on the artifact size. Finally, the third use case shows the potential of performing human model artifact simulations. RESULTS The numerical simulation approach shows a dice similarity coefficient of 0.74 between simulated and measured artifact sizes of metallic implants. The alternative artifact size calculation method presented in this study shows that the artifact size of the ASTM-based method is up to 50% smaller for complex shaped implants compared to the numerical-based approach. CONCLUSION In conclusion, the numerical approach could be used in the future to extend MR safety testing according to a revision of the ASTM F2119 standard and for design optimization during the development process of implants.
Collapse
Affiliation(s)
- Tobias Spronk
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Kokereiallee 7, Building C84, 45141, Essen, Germany.
- High-Field and Hybrid MR Imaging, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
- MRI-STaR Magnetic Resonance Institute for Safety GmbH, Technology and Research GmbH, Gelsenkirchen, Germany.
| | - Oliver Kraff
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Kokereiallee 7, Building C84, 45141, Essen, Germany
| | - Gregor Schaefers
- MRI-STaR Magnetic Resonance Institute for Safety GmbH, Technology and Research GmbH, Gelsenkirchen, Germany
- MR:Comp GmbH, Testing Services for MR Safety and Compatibility, Gelsenkirchen, Germany
| | - Harald H Quick
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Kokereiallee 7, Building C84, 45141, Essen, Germany
- High-Field and Hybrid MR Imaging, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| |
Collapse
|
3
|
Byvaltsev VA, Kalinin AA, Aliyev MA, Riew KD. Postoperative MRI Visualization of the Cervical Spine Following Cervical Disc Arthroplasty: A Prospective Single-Center Comparison of a Titanium and Cobalt-Chromium Prosthesis. Global Spine J 2023; 13:67-73. [PMID: 33504201 PMCID: PMC9837519 DOI: 10.1177/2192568221991105] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
STUDY DESIGN Prospective non-randomized single-center cohort study. OBJECTIVES To analyze the quality of postoperative magnetic resonance imaging of 2 structurally different cervical disc arthroplasty devices at the index and adjacent levels. METHODS A non-randomized, comparative, prospective, single-center study included 40 patients (23 men and 17 women) aged 32 (26-40) years. Two study groups were utilized: in the first (n = 20), a titanium prosthesis was used; in the second (n = 20), a cobalt-chromium implant was used. Evaluation of MRI studies before and after surgery was performed using sagittal and axial T2 weighted images by 2 specialists who were blinded to the prosthesis that was used. To determine the quality of an MRI image, the classification of Jarvik 2000, the radiological and orthopedic scales for assessing artifacts were used. RESULTS There was good-to-excellent inter-observer agreement for all of the MR parameters used for the titanium and satisfactory-to-good for the cobalt chromium group. The analysis of the quality of postoperative imaging using the Jarvik 2000 scale showed a statistically significant deterioration in MR images in the cobalt chromium group (P < 0.001), compared to the titanium (P = 0.091). Following a single-level total arthroplasty, the titanium group had better MRI images according to radiological and orthopedic scales (P < 0.001). CONCLUSION Titanium cervical disc arthroplasty devices result in superior postoperative MR imaging, as compared to cobalt chromium prostheses, as the latter significantly reduces image quality due to the pronounced ferromagnetic effect.
Collapse
Affiliation(s)
- Vadim A. Byvaltsev
- Irkutsk State Medical
University, Irkutsk, Russia
- Railway Clinical Hospital, Irkutsk,
Russia
- Vadim A. Byvaltsev, Irkutsk State Medical
University, Irkutsk, Russia; Railway Clinical Hospital, Irkutsk, Russia.
| | - Andrei A. Kalinin
- Irkutsk State Medical
University, Irkutsk, Russia
- Railway Clinical Hospital, Irkutsk,
Russia
| | | | - K. Daniel Riew
- Department of Orthopedic Surgery, Columbia University, New York, NY, USA
- Department of Neurological Surgery,
Weill Cornell Medical School, New York, NY, USA
| |
Collapse
|
4
|
Tan JL, Ragot DM, Chen JJ. Characterization of the echo-time dependence of spin-echo BOLD fMRI at 3 Tesla in grey and white matter. J Neurosci Methods 2022; 381:109691. [PMID: 36096237 DOI: 10.1016/j.jneumeth.2022.109691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 12/14/2022]
Affiliation(s)
| | - Don M Ragot
- Rotman Research Institute, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Canada
| | - J Jean Chen
- Rotman Research Institute, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Canada; Institute of Biomedical Engineering, University of Toronto, Canada.
| |
Collapse
|
5
|
Mizuno H, Aihara M, Sato K, Negishi C, Sasaguchi N, Kurihara H, Yoshimoto Y. Usefulness of 3D T1-Turbo Spin Echo Imaging for the Evaluation of Intracranial Stent Placement. JOURNAL OF NEUROENDOVASCULAR THERAPY 2022; 17:1-7. [PMID: 37501886 PMCID: PMC10370516 DOI: 10.5797/jnet.oa.2022-0039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/15/2022] [Indexed: 07/29/2023]
Abstract
Objective Evaluation of intracranial stent placement by MRI suffers the problems of signal artifacts during time-of-flight MRA (TOF-MRA). Therefore, angiographic examination is required for detailed intravascular assessment of the stent placement site. Recently, 3D T1-turbo spin echo (3D-TSE) has been developed for evaluation of carotid artery stent placement. We investigated the use of the 3D-TSE imaging method for the evaluation of intracranial vascular stent placement. Methods The subjects consisted of nine patients who underwent intracranial vascular stent placement between April 2015 and December 2019. Postoperatively, the lumens of the placed stents were measured by TOF-MRA, DSA, and 3D-TSE imaging. Analysis was performed by type of stent and placement site. Results The stents used were Neuroform Atlas (3 patients), LVIS (3 patients), LVIS Jr (2 patients), and Integrity (1 patient). TOF-MRA of the stent placement site showed defects in the image or poor visualization in all nine patients, whereas 3D-TSE imaging visualized the lumen at the stent indwelling site in all patients. The blood vessel diameter measured by the DSA and 3D-TSE imaging exhibited positive correlations regardless of the stent type and placement site. Conclusion 3D-TSE imaging allows visualization of the lumen of the site of an intracranial vascular stent, regardless of the type of stent or the vessel. Thus, this method may be useful for evaluating the vascular lumen of a lesion.
Collapse
Affiliation(s)
- Hiroyuki Mizuno
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Masanori Aihara
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Koji Sato
- Department of Neurosurgery, National Hospital Organization Takasaki General Medical Center, Takasaki, Gunma, Japan
| | - Chikashi Negishi
- Department of Radiation Diagnosis, National Hospital Organization Takasaki General Medical Center, Takasaki, Gunma, Japan
| | - Nobuo Sasaguchi
- Department of Neurosurgery, National Hospital Organization Takasaki General Medical Center, Takasaki, Gunma, Japan
| | - Hideyuki Kurihara
- Department of Neurosurgery, National Hospital Organization Takasaki General Medical Center, Takasaki, Gunma, Japan
| | - Yuhei Yoshimoto
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| |
Collapse
|
6
|
Spronk T, Kraff O, Kreutner J, Schaefers G, Quick HH. Development and evaluation of a numerical simulation approach to predict metal artifacts from passive implants in MRI. MAGMA (NEW YORK, N.Y.) 2022; 35:485-497. [PMID: 34655346 PMCID: PMC9188622 DOI: 10.1007/s10334-021-00966-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/27/2021] [Accepted: 10/01/2021] [Indexed: 11/08/2022]
Abstract
OBJECTIVE This study presents the development and evaluation of a numerical approach to simulate artifacts of metallic implants in an MR environment that can be applied to improve the testing procedure for MR image artifacts in medical implants according to ASTM F2119. METHODS The numerical approach is validated by comparing simulations and measurements of two metallic test objects made of titanium and stainless steel at three different field strengths (1.5T, 3T and 7T). The difference in artifact size and shape between the simulated and measured artifacts were evaluated. A trend analysis of the artifact sizes in relation to the field strength was performed. RESULTS The numerical simulation approach shows high similarity (between 75% and 84%) of simulated and measured artifact sizes of metallic implants. Simulated and measured artifact sizes in relation to the field strength resulted in a calculation guideline to determine and predict the artifact size at one field strength (e.g., 3T or 7T) based on a measurement that was obtained at another field strength only (e.g. 1.5T). CONCLUSION This work presents a novel tool to improve the MR image artifact testing procedure of passive medical implants. With the help of this tool detailed artifact investigations can be performed, which would otherwise only be possible with substantial measurement effort on different MRI systems and field strengths.
Collapse
Affiliation(s)
- Tobias Spronk
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Kokereiallee 7, Building C84, 45141, Essen, Germany.
- High-Field and Hybrid MR Imaging, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
- MRI-STaR Magnetic Resonance Institute for Safety, Technology and Research GmbH, Gelsenkirchen, Germany.
| | - Oliver Kraff
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Kokereiallee 7, Building C84, 45141, Essen, Germany
| | - Jakob Kreutner
- MRI-STaR Magnetic Resonance Institute for Safety, Technology and Research GmbH, Gelsenkirchen, Germany
- MR:Comp GmbH, Testing Services for MR Safety and Compatibility, Gelsenkirchen, Germany
| | - Gregor Schaefers
- MRI-STaR Magnetic Resonance Institute for Safety, Technology and Research GmbH, Gelsenkirchen, Germany
- MR:Comp GmbH, Testing Services for MR Safety and Compatibility, Gelsenkirchen, Germany
| | - Harald H Quick
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Kokereiallee 7, Building C84, 45141, Essen, Germany
- High-Field and Hybrid MR Imaging, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| |
Collapse
|
7
|
Kim JH, Ahn SJ, Park M, Kim YB, Joo B, Lee W, Suh SH. Follow-up imaging of clipped intracranial aneurysms with 3-T MRI: comparison between 3D time-of-flight MR angiography and pointwise encoding time reduction with radial acquisition subtraction-based MR angiography. J Neurosurg 2022; 136:1260-1265. [PMID: 34715654 DOI: 10.3171/2021.7.jns211197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/01/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Metallic susceptibility artifact due to implanted clips is a major limitation of using 3D time-of-flight magnetic resonance angiography (TOF-MRA) for follow-up imaging of clipped aneurysms (CAs). The purpose of this study was to compare pointwise encoding time reduction with radial acquisition (PETRA) subtraction-based MRA with TOF-MRA in terms of imaging quality and visibility of clip-adjacent arteries for use in follow-up imaging of CAs. METHODS Sixty-two patients with 73 CAs were included retrospectively in this comparative study. All patients underwent PETRA-MRA after TOF-MRA performed simultaneously with 3-T MRI between September 2019 and March 2020. Two neuroradiologists independently compared images obtained with both MRA modalities to evaluate overall image quality using a 4-point scale and visibility of the parent artery and branching vessels near the clips using a 3-point scale. Subgroup analysis was performed according to the number of clips (less-clipped [1-2 clips] vs more-clipped [≥ 3 clips] aneurysms). The ability to detect aneurysm recurrence was also assessed. RESULTS Compared with TOF-MRA, PETRA-MRA showed acceptable image quality (score of 3.97 ± 0.18 for TOF-MRA vs 3.73 ± 0.53 for PETRA-MRA) and had greater visibility of the adjacent vessels near the CAs (score of 1.25 ± 0.59 for TOF-MRA vs 2.27 ± 0.75 for PETRA-MRA, p < 0.0001). PETRA-MRA had greater visibility of vessels adjacent to less-clipped aneurysms (score of 2.39 ± 0.75 for less-clipped aneurysms vs 2.09 ± 0.72 for more-clipped aneurysms, p = 0.014). Of 73 CAs, aneurysm recurrence in 4 cases was detected using PETRA-MRA. CONCLUSIONS This study demonstrated that PETRA-MRA is superior to TOF-MRA for visualizing adjacent vessels near clips and can be an advantageous alternative to TOF-MRA for follow-up imaging of CAs.
Collapse
Affiliation(s)
- Jae Ho Kim
- 1Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; and
| | - Sung Jun Ahn
- 2Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Mina Park
- 2Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Yong Bae Kim
- 1Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; and
| | - Bio Joo
- 2Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Woosung Lee
- 1Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; and
| | - Sang Hyun Suh
- 2Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| |
Collapse
|
8
|
Li N, Tous C, Dimov IP, Cadoret D, Fei P, Majedi Y, Lessard S, Nosrati Z, Saatchi K, Hafeli UO, Tang A, Kadoury S, Martel S, Soulez G. Quantification and 3D localization of magnetically navigated superparamagnetic particles using MRI in phantom and swine chemoembolization models. IEEE Trans Biomed Eng 2022; 69:2616-2627. [PMID: 35167442 DOI: 10.1109/tbme.2022.3151819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Superparamagnetic nanoparticles (SPIONs) can be combined with tumor chemoembolization agents to form magnetic drug-eluting beads (MDEBs), which are navigated magnetically in the MRI scanner through the vascular system. We aim to develop a method to accurately quantify and localize these particles and to validate the method in phantoms and swine models. METHODS MDEBs were made of Fe3O4 SPIONs. After injected known numbers of MDEBs, susceptibility artifacts in three-dimensional (3D) volumetric interpolated breath-hold examination (VIBE) sequences were acquired in glass and Polyvinyl alcohol (PVA) phantoms, and two living swine. Image processing of VIBE images provided the volume relationship between MDEBs and their artifact at different VIBE acquisitions and post-processing parameters. Simulated hepatic-artery embolization was performed in vivo with an MRI-conditional magnetic-injection system, using the volume relationship to locate and quantify MDEB distribution. RESULTS Individual MDEBs were spatially identified, and their artifacts quantified, showing no correlation with magnetic-field orientation or sequence bandwidth, but exhibiting a relationship with echo time and providing a linear volume relationship. Two MDEB aggregates were magnetically steered into desired liver regions while the other 19 had no steering, and 25 aggregates were injected into another swine without steering. The MDEBs were spatially identified and the volume relationship showed accuracy in assessing the number of the MDEBs, with small errors (8.8%). CONCLUSION AND SIGNIFICANCE MDEBs were able to be steered into desired body regions and then localized using 3D VIBE sequences. The resulting volume relationship was linear, robust, and allowed for quantitative analysis of the MDEB distribution.
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Sousa JM, Appel L, Merida I, Heckemann RA, Costes N, Engström M, Papadimitriou S, Nyholm D, Ahlström H, Hammers A, Lubberink M. Accuracy and precision of zero-echo-time, single- and multi-atlas attenuation correction for dynamic [ 11C]PE2I PET-MR brain imaging. EJNMMI Phys 2020; 7:77. [PMID: 33369700 PMCID: PMC7769756 DOI: 10.1186/s40658-020-00347-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/09/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND A valid photon attenuation correction (AC) method is instrumental for obtaining quantitatively correct PET images. Integrated PET/MR systems provide no direct information on attenuation, and novel methods for MR-based AC (MRAC) are still under investigation. Evaluations of various AC methods have mainly focused on static brain PET acquisitions. In this study, we determined the validity of three MRAC methods in a dynamic PET/MR study of the brain. METHODS Nine participants underwent dynamic brain PET/MR scanning using the dopamine transporter radioligand [11C]PE2I. Three MRAC methods were evaluated: single-atlas (Atlas), multi-atlas (MaxProb) and zero-echo-time (ZTE). The 68Ge-transmission data from a previous stand-alone PET scan was used as reference method. Parametric relative delivery (R1) images and binding potential (BPND) maps were generated using cerebellar grey matter as reference region. Evaluation was based on bias in MRAC maps, accuracy and precision of [11C]PE2I BPND and R1 estimates, and [11C]PE2I time-activity curves. BPND was examined for striatal regions and R1 in clusters of regions across the brain. RESULTS For BPND, ZTE-MRAC showed the highest accuracy (bias < 2%) in striatal regions. Atlas-MRAC exhibited a significant bias in caudate nucleus (- 12%) while MaxProb-MRAC revealed a substantial, non-significant bias in the putamen (9%). R1 estimates had a marginal bias for all MRAC methods (- 1.0-3.2%). MaxProb-MRAC showed the largest intersubject variability for both R1 and BPND. Standardized uptake values (SUV) of striatal regions displayed the strongest average bias for ZTE-MRAC (~ 10%), although constant over time and with the smallest intersubject variability. Atlas-MRAC had highest variation in bias over time (+10 to - 10%), followed by MaxProb-MRAC (+5 to - 5%), but MaxProb showed the lowest mean bias. For the cerebellum, MaxProb-MRAC showed the highest variability while bias was constant over time for Atlas- and ZTE-MRAC. CONCLUSIONS Both Maxprob- and ZTE-MRAC performed better than Atlas-MRAC when using a 68Ge transmission scan as reference method. Overall, ZTE-MRAC showed the highest precision and accuracy in outcome parameters of dynamic [11C]PE2I PET analysis with use of kinetic modelling.
Collapse
Affiliation(s)
- João M Sousa
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
| | - Lieuwe Appel
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden
| | | | - Rolf A Heckemann
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | | | | | - Dag Nyholm
- Department of Neurology, Uppsala University Hospital, Uppsala, Sweden
- Department of Neurosciences, Uppsala University, Uppsala, Sweden
| | - Håkan Ahlström
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden
| | - Alexander Hammers
- King's College London & Guy's and St Thomas' PET Centre, King's College, London, UK
| | - Mark Lubberink
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
- Medical Physics, Uppsala University Hospital, Uppsala, Sweden
| |
Collapse
|