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Abbasi-Rad S, Cloos MA, Jin J, O'Brien K, Barth M. B 1 + inhomogeneity mitigation for diffusion weighted MRI at 7T using TR-FOCI pulses. Magn Reson Med 2024; 91:2508-2518. [PMID: 38321602 DOI: 10.1002/mrm.30024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 12/14/2023] [Accepted: 01/07/2024] [Indexed: 02/08/2024]
Abstract
PURPOSE The purpose of this study is to improve the image quality of diffusion-weighted images obtained with a single RF transmit channel 7 T MRI setup using time-resampled frequency-offset corrected inversion (TR-FOCI) pulses to refocus the spins in a twice-refocused spin-echo readout scheme. METHODS We replaced the conventional Shinnar-Le Roux-pulses in the twice refocused diffusion sequence with TR-FOCI pulses. The slice profiles were evaluated in simulation and experimentally in phantoms. The image quality was evaluated in vivo comparing the Shinnar-Le Roux and TR-FOCI implementation using a b value of 0 and of 1000 s/mm2. RESULTS The b0 and diffusion-weighted images acquired using the modified sequence improved the image quality across the whole brain. A region of interest-based analysis showed an SNR increase of 113% and 66% for the nondiffusion-weighted (b0) and the diffusion-weighted (b = 1000 s/mm2) images in the temporal lobes, respectively. Investigation of all slices showed that the adiabatic pulses mitigatedB 1 + $$ {B}_1^{+} $$ inhomogeneity globally using a conventional single-channel transmission setup. CONCLUSION The TR-FOCI pulse can be used in a twice-refocused spin-echo diffusion pulse sequence to mitigate the impact ofB 1 + $$ {B}_1^{+} $$ inhomogeneity on the signal intensity across the brain at 7 T. However, further work is needed to address SAR limitations.
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Affiliation(s)
- Shahrokh Abbasi-Rad
- Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland, Australia
| | - Martijn A Cloos
- Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland, Australia
- ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, St Lucia, Queensland, Australia
| | - Jin Jin
- ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, St Lucia, Queensland, Australia
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia
| | - Kieran O'Brien
- ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, St Lucia, Queensland, Australia
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia
| | - Markus Barth
- Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland, Australia
- ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, St Lucia, Queensland, Australia
- School of Electrical Engineering and Computer Science, The University of Queensland, St Lucia, Queensland, Australia
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Abbasi-Rad S, Norris DG. Adiabatic null passage for on-resonance magnetization transfer preparation. Magn Reson Med 2024; 91:133-148. [PMID: 37598419 DOI: 10.1002/mrm.29835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 07/08/2023] [Accepted: 08/01/2023] [Indexed: 08/22/2023]
Abstract
PURPOSE We propose a novel RF pulse providing an adiabatic null passage (ANP) for magnetization transfer preparation with improved insensitivity toB 1 + $$ {\mathrm{B}}_1^{+} $$ and B0 inhomogeneities and mitigated direct saturation and T2 effects. METHOD The phase modulation function of a 6-ms time-resampled frequency offset-corrected pulse was modified to achieve zero flip angle at the end of the pulse. The spectral response was simulated, and its insensitivity to B0 andB 1 + $$ {\mathrm{B}}_1^{+} $$ was investigated and compared with a phase-inverted (12 ¯ $$ \overline{2} $$ 1-1 ¯ $$ \overline{1} $$ 21 ¯ $$ \overline{1} $$ ) binomial pulse. The proposed pulse was implemented in a 2D-EPI pulse sequence to generate magnetization transfer (MT) contrast and MT ratio (MTR) maps. In vivo experiments were performed on 3 healthy participants with power-matched settings for ANP and the binomial pulse with the following parameters: 6-ms binomial pulse with a flip angle of 107° (shortest element) and pulse repetition period (PRP) of TRslice = 59 ms, three experiments with 6-ms ANP and constant MT used overdrive factor (OF)/PRP values of 1/TRslice ,2 $$ \sqrt{2} $$ /2TRslice , and3 $$ \sqrt{3} $$ /3TRslice . RESULTS At gray matter (white matter) in vivo, the MTR decreased from 61% (64%) at OF = 1 to 38% (42%) applying ANP with an OF =3 $$ \sqrt{\mathsf{3}} $$ and PRP = 3 TRslice , demonstrating the mitigation of T2 /direct effect by 22% (22%). Bloch-McConnell simulations gave similar values. In vivo experiments showed significant improvement in the MTR values for areas with high B0 inhomogeneity. CONCLUSION ANP pulse was shown to be advantageous over its binomial counterpart in providing MT contrast by mitigating the T2 effect and direct saturation of the liquid pool as well as reduced sensitivity toB 1 + $$ {\mathrm{B}}_1^{+} $$ and B0 inhomogeneity.
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Affiliation(s)
- Shahrokh Abbasi-Rad
- Donders Institute for Brain, Cognition and Behaviour, Donders Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, Netherlands
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - David G Norris
- Donders Institute for Brain, Cognition and Behaviour, Donders Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, Netherlands
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
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Talebi M, Abbasi-Rad S, Malekzadeh M, Shahgholi M, Ardakani AA, Foudeh K, Rad HS. Cortical Bone Mechanical Assessment via Free Water Relaxometry at 3 T. J Magn Reson Imaging 2021; 54:1744-1751. [PMID: 34142413 DOI: 10.1002/jmri.27765] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Investigation of cortical bone using magnetic resonance imaging is a developing field, which uses short/ultrashort echo time (TE) pulse sequences to quantify bone water content and to obtain indirect information about bone microstructure. PURPOSE To improve the accuracy of the previously proposed technique of free water T1 quantification and to seek the relationship between cortical bone free water T1 and its mechanical competence. STUDY TYPE Prospective. SUBJECTS Twenty samples of bovine tibia bone. FIELD STRENGTH/SEQUENCES 3.0 T; ultra-fast two-dimensional gradient echo, Radio frequency-spoiled three-dimensional gradient echo. ASSESSMENT Cortical bone free water T1 was quantified via three different methods: inversion recovery (IR), variable flip angle (VFA), and variable repetition time (VTR). Signal-to-noise ratio was measured by dividing the signal of each segmented sample to background noise. Segmentation was done manually. The effect of noise on T1 quantification was evaluated. Then, the samples were subjected to mechanical compression test to measure the toughness, yield stress, ultimate stress, and Young modulus. STATISTICAL TESTS All the statistical analysis (Shapiro-Wilk, way analysis of variance, paired t test, Pearson correlation, and Bland-Altman plot) were done using SPSS. RESULTS Significant difference was found between T1 quantification groups (P < 0.05). Average T1 of each quantification method differed significantly after adding noise (P < 0.05). VFA-T1 values significantly correlated with toughness (r = -0.68, P < 0.05), ultimate stress (r = -0.71, P < 0.05), and yield stress (r = -0.62, P < 0.05). No significant correlation was found between VTR-T1 values and toughness (P = 0.07), ultimate stress (P = 0.47), yield stress (P = 0.30), and Young modulus (P = 0.39). DATA CONCLUSION Pore water T1 value is associated with bone mechanical competence, and VFA method employing short-TE pulse sequence seems a superior technique to VTR method for this quantification. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: 1.
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Affiliation(s)
- Mahsa Talebi
- Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.,The Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran
| | - Shahrokh Abbasi-Rad
- The Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran
| | - Malakeh Malekzadeh
- The Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran.,Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohamad Shahgholi
- The Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran.,Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
| | - Ali A Ardakani
- Department of Radiology Technology, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kimia Foudeh
- Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
| | - Hamidreza S Rad
- Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.,The Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran.,Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.,Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
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Abbasi-Rad S, O'Brien K, Kelly S, Vegh V, Rodell A, Tesiram Y, Jin J, Barth M, Bollmann S. Improving FLAIR SAR efficiency at 7T by adaptive tailoring of adiabatic pulse power through deep learning B 1 + estimation. Magn Reson Med 2020; 85:2462-2476. [PMID: 33226685 DOI: 10.1002/mrm.28590] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 01/22/2023]
Abstract
PURPOSE The purpose of this study is to demonstrate a method for specific absorption rate (SAR) reduction for 2D T2 -FLAIR MRI sequences at 7 T by predicting the required adiabatic radiofrequency (RF) pulse power and scaling the RF amplitude in a slice-wise fashion. METHODS We used a time-resampled frequency-offset corrected inversion (TR-FOCI) adiabatic pulse for spin inversion in a T2 -FLAIR sequence to improve B 1 + homogeneity and calculated the pulse power required for adiabaticity slice-by-slice to minimize the SAR. Drawing on the implicit B 1 + inhomogeneity in a standard localizer scan, we acquired 3D AutoAlign localizers and SA2RAGE B 1 + maps in 28 volunteers. Then, we trained a convolutional neural network (CNN) to estimate the B 1 + profile from the localizers and calculated pulse scale factors for each slice. We assessed the predicted B 1 + profiles and the effect of scaled pulse amplitudes on the FLAIR inversion efficiency in oblique transverse, sagittal, and coronal orientations. RESULTS The predicted B 1 + amplitude maps matched the measured ones with a mean difference of 9.5% across all slices and participants. The slice-by-slice scaling of the TR-FOCI inversion pulse was most effective in oblique transverse orientation and resulted in a 1 min and 30 s reduction in SAR induced delay time while delivering identical image quality. CONCLUSION We propose a SAR reduction technique based on the estimation of B 1 + profiles from standard localizer scans using a CNN and show that scaling the inversion pulse power slice-by-slice for FLAIR sequences at 7T reduces SAR and scan time without compromising image quality.
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Affiliation(s)
- Shahrokh Abbasi-Rad
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Kieran O'Brien
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia
| | - Samuel Kelly
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Viktor Vegh
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia
| | - Anders Rodell
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia
| | - Yasvir Tesiram
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Jin Jin
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia
| | - Markus Barth
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia.,School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Queensland, Australia
| | - Steffen Bollmann
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia.,School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Queensland, Australia
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Malekzadeh M, Abbasi-Rad S, Keyak JH, Nabil M, Asadi M, Mobini N, Naghdi P, Emadi H, Saligheh Rad H, Shiran MB. Liquid Calibration Phantoms in Ultra-Low-Dose QCT for the Assessment of Bone Mineral Density. J Clin Densitom 2020; 23:108-116. [PMID: 30902572 DOI: 10.1016/j.jocd.2019.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 02/17/2019] [Accepted: 02/18/2019] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Cortical bone is affected by metabolic diseases. Some studies have shown that lower cortical bone mineral density (BMD) is related to increases in fracture risk which could be diagnosed by quantitative computed tomography (QCT). Nowadays, hybrid iterative reconstruction-based (HIR) computed tomography (CT) could be helpful to quantify the peripheral bone tissue. A key focus of this paper is to evaluate liquid calibration phantoms for BMD quantification in the tibia and under hybrid iterative reconstruction-based-CT with the different hydrogen dipotassium phosphate (K2HPO4) concentrations phantoms. METHODOLOGY Four ranges of concentrations of K2HPO4 were made and tested with 2 exposure settings. Accuracy of the phantoms with ash gravimetry and intermediate K2HPO4 concentration as hypothetical patients were evaluated. The correlations and mean differences between measured equivalent QCT BMD and ash density as a gold standard were calculated. Relative percentage error (RPE) in CT numbers of each concentration over a 6-mo period was reported. RESULTS The correlation values (R2 was close to 1.0), suggested that the precision of QCT-BMD measurements using standard and ultra-low dose settings were similar for all phantoms. The mean differences between QCT-BMD and the ash density for low concentrations (about 93 mg/cm3) were lower than high concentration phantoms with 135 and 234 mg/cm3 biases. In regard to accuracy test for hypothetical patient, RPE was up to 16.1% for the low concentration (LC) phantom for the case of high mineral content. However, the lowest RPE (0.4 to 1.8%) was obtained for the high concentration (HC) phantom, particularly for the high mineral content case. In addition, over 6 months, the K2HPO4 concentrations increased 25% for 50 mg/cm3 solution and 0.7 % for 1300 mg/cm3 solution in phantoms. CONCLUSION The excellent linear correlations between the QCT equivalent density and the ash density gold standard indicate that QCT can be used with submilisivert radiation dose. We conclude that using liquid calibration phantoms with a range of mineral content similar to that being measured will minimize bias. Finally, we suggest performing BMD measurements with ultra-low dose scan concurrent with iterative-based reconstruction to reduce radiation exposure.
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Affiliation(s)
- Malakeh Malekzadeh
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shahrokh Abbasi-Rad
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Joyce H Keyak
- Department of Radiological Sciences, Department of Biomedical Engineering and Department of Mechanical and Aerospace Engineering, University of California, Irvine, CA, USA
| | - Mahnaz Nabil
- Department of Mathematics, Islamic Azad University, Qazvin Branch, Qazvin, Iran
| | - Mojgan Asadi
- Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran; Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Nazanin Mobini
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Parisa Naghdi
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Emadi
- Department of Applied Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran
| | - Hamidreza Saligheh Rad
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Bagher Shiran
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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Malekzadeh M, Asadi M, Abbasi-Rad S, Abolghasemi J, Hamidi Z, Talebi M, Shiran MB, Saligheh Rad H. MDCT-QCT, QUS, and DXA in healthy adults: An intermodality comparison. Med J Islam Repub Iran 2019; 33:156. [PMID: 32280662 PMCID: PMC7137819 DOI: 10.34171/mjiri.33.156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Indexed: 11/05/2022] Open
Abstract
Background: Cortical deceleration is the main reason for bone loss at peripheral sites. It was suggested that when peripheral bones were assessed for osteoporosis, management and therapy can be administered early. The main aim of this study was to assess the relationships between the central and peripheral measurements at different skeleton bone sites (spine, femur, forearm, tibia, and calcaneus) with available modalities: DXA, QUS, and MDCT-QCT. Methods: The volunteers recruited in this study did not have any history or evidence of metabolic bone disease. Blood test and DXA measurements were used as inclusion criteria to select 40 healthy participants. The selected volunteers underwent 3 imaging modalities: QCT, DXA, and QUS. DXA-based measurements were made on 3 sites, including spine, femur, and forearm. QCT and QUS measurements were done for distal of tibia and calcaneus bones, respectively. The extracted parameters from the 3 modalities were analyzed using a bivariate (Pearson) correlation (r) in statistical software. Results: The results showed moderate to good correlations between spongy bones in central and peripheral sites from all the modalities. However, there was no correlation between MDCT measures and central bone values. According to correlations between different peripheral sits, aBMD of 33% radius and trabecular vBMD in 38% distal tibia showed weak but significant relationship between peripheral bones (r=-0.342, p=0.044). Conclusion: The findings demonstrated how bones in central and peripheral sites were correlated. Multimodality imaging was used in this group of healthy volunteers. Also, it was found that QCT-based MDCT needs more optimization and requires further investigations.
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Affiliation(s)
- Malakeh Malekzadeh
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mojgan Asadi
- Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Shahrokh Abbasi-Rad
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
- Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Jamileh Abolghasemi
- Department of Biostatistics, School of public health, Iran University of Medical Sciences, Tehran, Iran
| | - Zohreh Hamidi
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahsa Talebi
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
- Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Bagher Shiran
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Finetech in Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Saligheh Rad
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
- Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
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Malekzadeh M, Asadi M, Abbasi-Rad S, Abolghasemi J, Hamidi Z, Talebi M, Shiran MB, Saligheh Rad H. MDCT-QCT, QUS, and DXA in healthy adults: An intermodality comparison. Med J Islam Repub Iran 2019. [DOI: 10.47176/mjiri.33.156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Malekzadeh M, Abbasi-Rad S, Shahgholi M, Naghdi P, Hoseini MS, Yazdi NA, Shiran MB, Rad HS. Design and Validation of Synchronous QCT Calibration Phantom: Practical Methodology. J Med Imaging Radiat Sci 2018; 50:157-162. [PMID: 30777238 DOI: 10.1016/j.jmir.2018.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/16/2018] [Accepted: 10/01/2018] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Quantitative computed tomography (QCT) can supplement dual x-ray absorptiometry by enabling geometric and compartmental bone assessments. Whole-body spiral CT scanners are widely available and require a short scanning time of seconds, in contrast to peripheral QCT scanners, which require several minutes of scanning time. This study designed and evaluated the accuracy and precision of a homemade QCT calibration phantom using a whole-body spiral CT scanner. MATERIALS AND METHODS The QCT calibration phantom consisted of K2HPO4 solutions as reference. The reference material with various concentrations of 0, 50, 100, 200, 400, 1000, and 1200 mg/cc of K2HPO4 in water were used. For designing the phantom, we used the ABAQUS software. RESULTS The phantoms were used for performance assessment of QCT method through measurement of accuracy and precision errors, which were generally less than 5.1% for different concentrations. The correlation between CT numbers and concentration were close to one (R2 = 0.99). DISCUSSION Because whole-body spiral CT scanners allow central bone densitometry, evaluating the accuracy and precision for the easy to use calibration phantom may improve the QCT bone densitometry test. CONCLUSION This study provides practical directions for applying a homemade calibration phantom for bone mineral density quantification in QCT technique.
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Affiliation(s)
- Malakeh Malekzadeh
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shahrokh Abbasi-Rad
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohamad Shahgholi
- Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad, Iran
| | - Parisa Naghdi
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
| | - Marzieh Sadat Hoseini
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
| | - Niloofar Ayoobi Yazdi
- Advanced Diagnostic and Interventional Radiology (ADIR) Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Bagher Shiran
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Saligheh Rad
- Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.
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Abbasi-Rad S, Saligheh Rad H. Quantification of Human Cortical Bone Bound and Free Water in Vivo with Ultrashort Echo Time MR Imaging: A Model-based Approach. Radiology 2017; 283:862-872. [DOI: 10.1148/radiol.2016160780] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Akbari A, Abbasi-Rad S, Rad HS. T1 correlates age: A short-TE MR relaxometry study in vivo on human cortical bone free water at 1.5T. Bone 2016; 83:17-22. [PMID: 26475122 DOI: 10.1016/j.bone.2015.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 10/03/2015] [Accepted: 10/12/2015] [Indexed: 11/30/2022]
Abstract
Large pores of human cortical bone (>30μm) are filled with fluids, essentially consisting of water, suggesting that cortical bone free water can be considered as a reliable surrogate measure of cortical bone porosity and hence quality. Signal from such pores can be reliably captured using Short Echo Time (STE) pulse sequence with echo-time in the range of 1-1.5msec (which should be judiciously selected correspond to T2(⁎) value of free water molecules). Furthermore, it is well-known that cortical bone T1-relaxivity is a function of its geometry, suggesting that cortical bone free water increases with age. In this work, we quantified cortical bone free water longitudinal relaxation time (T1) by a Dual-TR technique using STE pulse sequence. In the sequel, we investigated relationship between STE-derived cortical bone free water T1-values and age in a group of healthy volunteers (thirty subjects covering the age range of 20-70years) at 1.5T. Preliminary results showed that cortical bone free water T1 highly correlates with age (r(2)=0.73, p<0.0001), representing cortical bone free water T1 as a reliable indicator of cortical bone porosity and age-related deterioration. It can be concluded that STE-MRI can be utilized as proper alternative in quantifying cortical bone porosity parameters in-vivo, with the advantages of widespread clinical availability and being cost-effective.
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Affiliation(s)
- Atena Akbari
- Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Shahrokh Abbasi-Rad
- Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Saligheh Rad
- Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.
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