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Geng W, Pan L, Shen L, Sha Y, Sun J, Yu S, Qiu J, Xing W. Evaluating renal iron overload in diabetes mellitus by blood oxygen level-dependent magnetic resonance imaging: a longitudinal experimental study. BMC Med Imaging 2022; 22:200. [PMID: 36401188 PMCID: PMC9675154 DOI: 10.1186/s12880-022-00939-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Iron overload plays a critical role in the pathogenesis of diabetic nephropathy. Non-invasive evaluation of renal iron overload in diabetes in the management and intervention of diabetic nephropathy is of great significance. This study aimed to explore the feasibility of blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in evaluating renal iron overload in diabetes using a rabbit model. METHODS The rabbits were randomly divided into control, iron-overload (I), diabetes (D), and diabetes with iron-overload (DI) groups (each n = 19). The diabetes models were generated by injecting intravenous alloxan solution, and the iron-overload models were generated by injecting intramuscular iron-dextran. BOLD MRI was performed immediately (week 0) and at week 4, 8, and 12 following modeling. The differences in renal cortex (CR2*) and outer medulla R2* (MR2*) and the ratio of MR2*-CR2* (MCR) across the different time points were compared. RESULTS Iron was first deposited in glomeruli in the I group and in proximal tubular cells in renal cortex in the D group. In the DI group, there was iron deposition in both glomeruli and proximal tubular cells at week 4, and the accumulation increased subsequently. The degree of kidney injury and iron overload was more severe in the DI group than those in the I and D groups at week 12. At week 8 and 12, the CR2* and MR2* in the DI group were higher than those in the I and D groups (all P < 0.05). The MCR in the I, D, and DI groups decreased from week 0 to 4 (all P < 0.001), and that in the I group increased from week 8 to 12 (P = 0.034). CR2* and MR2* values displayed different trends from week 0-12. Dynamic MCR curves in the D and DI groups were different from that in the I group. CONCLUSION It presents interactions between diabetes and iron overload in kidney injury, and BOLD MRI can be used to evaluate renal iron overload in diabetes.
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Affiliation(s)
- Weiwei Geng
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China
| | - Liang Pan
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China
| | - Liwen Shen
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China
| | - Yuanyuan Sha
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China
| | - Jun Sun
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China
| | - Shengnan Yu
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China
| | - Jianguo Qiu
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China.
| | - Wei Xing
- Department of Radiology, Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, Jiangsu, China.
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Alipour A, Viswanathan AN, Watkins RD, Elahi H, Loew W, Meyer E, Morcos M, Halperin HR, Schmidt EJ. An endovaginal MRI array with a forward-looking coil for advanced gynecological cancer brachytherapy procedures: Design and initial results. Med Phys 2021; 48:7283-7298. [PMID: 34520574 PMCID: PMC8817785 DOI: 10.1002/mp.15228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 08/20/2021] [Accepted: 09/04/2021] [Indexed: 02/03/2023] Open
Abstract
PURPOSE To develop an endovaginal MRI array that provides signal enhancement forward into the posterior parametrium and sideways into the vaginal wall, accelerating multiple-contrast detection of residual tumors that survive external beam radiation. The array's enclosure should form an obturator for cervical cancer brachytherapy, allowing integration with MRI-guided catheter placement, CT, and interstitial radiation dose delivery. METHODS The endovaginal array consisted of forward-looking and sideways-looking components. The forward-looking element imaged the cervix and posterior endometrium, and the sideways-looking elements imaged the vaginal wall. Electromagnetic simulation was performed to optimize the geometry of a forward-looking coil placed on a conductive-metallic substrate, extending the forward penetration above the coil's tip. Thereafter, an endovaginal array with one forward-looking coil and four sideways-looking elements was constructed and tested at 1.5 Tesla in saline and gel phantoms, and three sexually mature swine. Each coil's tuning, matching, and decoupling were optimized theoretically, implemented with electronic circuits, and validated with network-analyzer measurements. The array enclosure emulates a conventional brachytherapy obturator, allowing use of the internal imaging array together with tandem coils and interstitial catheters, as well as use of the enclosure alone during CT and radiation delivery. To evaluate the receive magnetic field ( B 1 - ) spatial profile, the endovaginal array's specific absorption-rate (SAR) distribution was simulated inside a gel ASTM phantom to determine extreme heating locations in advance of a heating test. Heating tests were then performed during high SAR imaging in a gel phantom at the predetermined locations, testing compliance with MRI safety standards. To assess array imaging performance, signal-to-noise-ratios (SNR) were calculated in a saline phantom and in vivo. Swine images were acquired with the endovaginal array combined with the scanner's body and spine arrays. RESULTS Simulated B 1 - profiles for the forward-looking lobe pattern, obtained while varying several geometric parameters, disclosed that a forward-looking coil placed on a metal-backed substrate could double the effective forward penetration from approximately 25 to ∼40 mm. An endovaginal array, enclosed in an obturator enclosure was then constructed, with all coils tuned, matched, and decoupled. The ASTM gel-phantom SAR test showed that peak local SAR was 1.2 W/kg in the forward-looking coil and 0.3 W/kg in the sideways-looking elements, well within ASTM/FDA/IEC guidelines. A 15-min 4 W/kg average SAR imaging experiment resulted in less than 2o C temperature increase, also within ASTM/FDA/IEC heating limits. In a saline phantom, the forward-looking coil and sideways-looking array's SNR was four to eight times, over a 20-30 mm field-of-view (FOV), and five to eight times, over a 15-25 mm FOV, relative to the spine array's SNR, respectively. In three sexually mature swine, the forward-looking coil provided a 5 + 0.2 SNR enhancement factor within the cervix and posterior endometrium, and the sideways-looking array provided a 4 + 0.2 SNR gain factor in the vaginal wall, relative to the Siemens spine array, demonstrating that the array could significantly reduce imaging time. CONCLUSIONS Higher SNR gynecological imaging is supported by forward-looking and sideways-looking coils. A forward-looking endovaginal coil for cervix and parametrium imaging was built with optimized metal backing. Array placement within an obturator enhanced integration with the brachytherapy procedure and accelerated imaging for detecting postexternal-beam residual tumors.
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Affiliation(s)
- Akbar Alipour
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA,Department of Radiology, Mount Sinai School of Medicine, New York, New York, USA
| | - Akila N. Viswanathan
- Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ronald D. Watkins
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Hassan Elahi
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Wolfgang Loew
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Eric Meyer
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Marc Morcos
- Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Henry R. Halperin
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ehud J. Schmidt
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA,Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland, USA
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Fields EC, Hazell S, Morcos M, Schmidt EJ, Chargari C, Viswanathan AN. Image-Guided Gynecologic Brachytherapy for Cervical Cancer. Semin Radiat Oncol 2020; 30:16-28. [PMID: 31727296 DOI: 10.1016/j.semradonc.2019.08.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The incorporation of magnetic resonance imaging in brachytherapy has resulted in an increased use of interstitial catheters in order to create a comprehensive treatment plan that covers the visualized tumor. However, the insertion with passive, image-guidance requires estimating the location of the tumor during the insertion process, rather than visualizing and inserting the catheters directly to the desired location under active tracking. In order to treat residual disease, multiparametric MR sequences can enhance the information available to the clinician. The precision availed by MR-guided brachytherapy results in substantial improvements in needle positioning, and resulting treatment plans.
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Affiliation(s)
- Emma C Fields
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA
| | - Sarah Hazell
- Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins Medicine, Baltimore, MD
| | - Marc Morcos
- Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins Medicine, Baltimore, MD
| | - Ehud J Schmidt
- Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins Medicine, Baltimore, MD
| | - Cyrus Chargari
- Department of Radiotherapy, Gustave Roussy Cancer Campus, Villejuif, France
| | - Akila N Viswanathan
- Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins Medicine, Baltimore, MD.
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Balasubramanian M, Polimeni JR, Mulkern RV. In vivo measurements of irreversible and reversible transverse relaxation rates in human basal ganglia at 7 T: making inferences about the microscopic and mesoscopic structure of iron and calcification deposits. NMR IN BIOMEDICINE 2019; 32:e4140. [PMID: 31322331 PMCID: PMC6817385 DOI: 10.1002/nbm.4140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 05/29/2019] [Accepted: 06/12/2019] [Indexed: 05/24/2023]
Abstract
The goal of this study was to measure irreversible and reversible transverse relaxation rates in the globus pallidus and putamen at 7 T, and to use these rates to make inferences about the sub-voxel structure of iron and calcification deposits. Gradient Echo Sampling of a Spin Echo (GESSE) data were acquired at 7 T on eighteen volunteers spanning a large range of ages (23-85 years), with calcifications in the globus pallidus incidentally observed in one volunteer. Maps of transverse relaxation rates were derived from the GESSE data, and the mean value of these rates in globus pallidus and putamen was estimated for each volunteer. Both irreversible and reversible transverse relaxation rates increased with the expected age-dependent iron content in these structures, except for the individual with calcifications for whom extremely large reversible relaxation rates but normal irreversible relaxation rates were found in the globus pallidus. Given the sensitivity of irreversible and reversible transverse relaxation rates to microscopic and mesoscopic field variations, respectively, our findings suggest that joint consideration of these rates may yield information not only about the amount of iron and calcification deposited in the brain, but also about the sub-voxel structure of these deposits, perhaps revealing certain aspects of their geometry and cellular distribution.
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Affiliation(s)
- Mukund Balasubramanian
- Harvard Medical School, Boston, MA, USA
- Department of Radiology, Boston Children’s Hospital, Boston, MA, USA
| | - Jonathan R. Polimeni
- Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Robert V. Mulkern
- Harvard Medical School, Boston, MA, USA
- Department of Radiology, Boston Children’s Hospital, Boston, MA, USA
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Dou W, Mastrogiacomo S, Veltien A, Alghamdi HS, Walboomers XF, Heerschap A. Visualization of calcium phosphate cement in teeth by zero echo time 1 H MRI at high field. NMR IN BIOMEDICINE 2018; 31:e3859. [PMID: 29160917 DOI: 10.1002/nbm.3859] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 08/25/2017] [Accepted: 10/13/2017] [Indexed: 06/07/2023]
Abstract
1 H magnetic resonance imaging (MRI) by a zero echo time (ZTE) sequence is an excellent method to image teeth. Calcium phosphate cement (CPC) materials are applied in the restoration of tooth lesions, but it has not yet been investigated whether they can be detected by computed tomography (CT) or MRI. The aim of this study was to optimize high-field ZTE imaging to enable the visualization of a new CPC formulation implanted in teeth and to apply this in the assessment of its decomposition in vivo. CPC was implanted in three human and three goat teeth ex vivo and in three goat teeth in vivo. An ultrashort echo time (UTE) sequence with multiple flip angles and echo times was applied at 11.7 T to measure T1 and T2 * values of CPC, enamel and dentin. Teeth with CPC were imaged with an optimized ZTE sequence. Goat teeth implanted with CPC in vivo were imaged after 7 weeks ex vivo. T2 * relaxation of implanted CPC, dentin and enamel was better fitted by a model assuming a Gaussian rather than a Lorentzian distribution. For CPC and human enamel and dentin, the average T2 * values were 273 ± 19, 562 ± 221 and 476 ± 147 μs, respectively, the average T2 values were 1234 ± 27, 963 ± 151 and 577 ± 41 μs, respectively, and the average T1 values were 1065 ± 45, 972 ± 40 and 903 ± 7 ms, respectively. In ZTE images, CPC had a higher signal-to-noise-ratio than dentin and enamel because of the higher water content. Seven weeks after in vivo implantation, the CPC-filled lesions showed less homogeneous structures, a lower T1 value and T2 * separated into two components. MRI by ZTE provides excellent contrast for CPC in teeth and allows its decomposition to be followed.
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Affiliation(s)
- Weiqiang Dou
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Simone Mastrogiacomo
- Department of Biomaterials, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Andor Veltien
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Hamdan S Alghamdi
- Department of Biomaterials, Radboud University Medical Center, Nijmegen, the Netherlands
- College of Dentistry Research Center, King Saud University, Riyadh, Saudi Arabia
| | - X Frank Walboomers
- Department of Biomaterials, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
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Lyng H, Malinen E. Hypoxia in cervical cancer: from biology to imaging. Clin Transl Imaging 2017; 5:373-388. [PMID: 28804704 PMCID: PMC5532411 DOI: 10.1007/s40336-017-0238-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 06/24/2017] [Indexed: 12/14/2022]
Abstract
PURPOSE Hypoxia imaging may improve identification of cervical cancer patients at risk of treatment failure and be utilized in treatment planning and monitoring, but its clinical potential is far from fully realized. Here, we briefly describe the biology of hypoxia in cervix tumors of relevance for imaging, and evaluate positron emission tomography (PET) and magnetic resonance imaging (MRI) techniques that have shown promise for assessing hypoxia in a clinical setting. We further discuss emerging imaging approaches, and how imaging can play a role in future treatment strategies to target hypoxia. METHODS We performed a PubMed literature search, using keywords related to imaging and hypoxia in cervical cancer, with a particular emphasis on studies correlating imaging with other hypoxia measures and treatment outcome. RESULTS Only a few and rather small studies have utilized PET with tracers specific for hypoxia, and no firm conclusions regarding preferred tracer or clinical potential can be drawn so far. Most studies address indirect hypoxia imaging with dynamic contrast-enhanced techniques. Strong evidences for a role of these techniques in hypoxia imaging have been presented. Pre-treatment images have shown significant association to outcome in several studies, and images acquired during fractionated radiotherapy may further improve risk stratification. Multiparametric MRI and multimodality PET/MRI enable combined imaging of factors of relevance for tumor hypoxia and warrant further investigation. CONCLUSIONS Several imaging approaches have shown promise for hypoxia imaging in cervical cancer. Evaluation in large clinical trials is required to decide upon the optimal modality and approach.
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Affiliation(s)
- Heidi Lyng
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Eirik Malinen
- Department of Medical Physics, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
- Department of Physics, University of Oslo, Oslo, Norway
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