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Vu BTD, Kamona N, Kim Y, Ng JJ, Jones BC, Wehrli FW, Song HK, Bartlett SP, Lee H, Rajapakse CS. Three contrasts in 3 min: Rapid, high-resolution, and bone-selective UTE MRI for craniofacial imaging with automated deep-learning skull segmentation. Magn Reson Med 2024. [PMID: 39219299 DOI: 10.1002/mrm.30275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/17/2024] [Accepted: 08/12/2024] [Indexed: 09/04/2024]
Abstract
PURPOSE Ultrashort echo time (UTE) MRI can be a radiation-free alternative to CT for craniofacial imaging of pediatric patients. However, unlike CT, bone-specific MR imaging is limited by long scan times, relatively low spatial resolution, and a time-consuming bone segmentation workflow. METHODS A rapid, high-resolution UTE technique for brain and skull imaging in conjunction with an automatic segmentation pipeline was developed. A dual-RF, dual-echo UTE sequence was optimized for rapid scan time (3 min) and smaller voxel size (0.65 mm3). A weighted least-squares conjugate gradient method for computing the bone-selective image improves bone specificity while retaining bone sensitivity. Additionally, a deep-learning U-Net model was trained to automatically segment the skull from the bone-selective images. Ten healthy adult volunteers (six male, age 31.5 ± 10 years) and three pediatric patients (two male, ages 12 to 15 years) were scanned at 3 T. Clinical CT for the three patients were obtained for validation. Similarities in 3D skull reconstructions relative to clinical standard CT were evaluated based on the Dice similarity coefficient and Hausdorff distance. Craniometric measurements were used to assess geometric accuracy of the 3D skull renderings. RESULTS The weighted least-squares method produces images with enhanced bone specificity, suppression of soft tissue, and separation from air at the sinuses when validated against CT in pediatric patients. Dice similarity coefficient overlap was 0.86 ± 0.05, and the 95th percentile Hausdorff distance was 1.77 ± 0.49 mm between the full-skull binary masks of the optimized UTE and CT in the testing dataset. CONCLUSION An optimized MRI acquisition, reconstruction, and segmentation workflow for craniofacial imaging was developed.
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Affiliation(s)
- Brian-Tinh Duc Vu
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nada Kamona
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yohan Kim
- Division of Plastic, Reconstructive and Oral Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Jinggang J Ng
- Division of Plastic, Reconstructive and Oral Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Brandon C Jones
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Felix W Wehrli
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hee Kwon Song
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Scott P Bartlett
- Division of Plastic, Reconstructive and Oral Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Hyunyeol Lee
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- School of Electronics Engineering, Kyungpook National University, Daegu, Republic of Korea
| | - Chamith S Rajapakse
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Jones BC, Wehrli FW, Kamona N, Deshpande RS, Vu BTD, Song HK, Lee H, Grewal RK, Chan TJ, Witschey WR, MacLean MT, Josselyn NJ, Iyer SK, Al Mukaddam M, Snyder PJ, Rajapakse CS. Automated, calibration-free quantification of cortical bone porosity and geometry in postmenopausal osteoporosis from ultrashort echo time MRI and deep learning. Bone 2023; 171:116743. [PMID: 36958542 PMCID: PMC10121925 DOI: 10.1016/j.bone.2023.116743] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/01/2023] [Accepted: 03/16/2023] [Indexed: 03/25/2023]
Abstract
BACKGROUND Assessment of cortical bone porosity and geometry by imaging in vivo can provide useful information about bone quality that is independent of bone mineral density (BMD). Ultrashort echo time (UTE) MRI techniques of measuring cortical bone porosity and geometry have been extensively validated in preclinical studies and have recently been shown to detect impaired bone quality in vivo in patients with osteoporosis. However, these techniques rely on laborious image segmentation, which is clinically impractical. Additionally, UTE MRI porosity techniques typically require long scan times or external calibration samples and elaborate physics processing, which limit their translatability. To this end, the UTE MRI-derived Suppression Ratio has been proposed as a simple-to-calculate, reference-free biomarker of porosity which can be acquired in clinically feasible acquisition times. PURPOSE To explore whether a deep learning method can automate cortical bone segmentation and the corresponding analysis of cortical bone imaging biomarkers, and to investigate the Suppression Ratio as a fast, simple, and reference-free biomarker of cortical bone porosity. METHODS In this retrospective study, a deep learning 2D U-Net was trained to segment the tibial cortex from 48 individual image sets comprised of 46 slices each, corresponding to 2208 training slices. Network performance was validated through an external test dataset comprised of 28 scans from 3 groups: (1) 10 healthy, young participants, (2) 9 postmenopausal, non-osteoporotic women, and (3) 9 postmenopausal, osteoporotic women. The accuracy of automated porosity and geometry quantifications were assessed with the coefficient of determination and the intraclass correlation coefficient (ICC). Furthermore, automated MRI biomarkers were compared between groups and to dual energy X-ray absorptiometry (DXA)- and peripheral quantitative CT (pQCT)-derived BMD. Additionally, the Suppression Ratio was compared to UTE porosity techniques based on calibration samples. RESULTS The deep learning model provided accurate labeling (Dice score 0.93, intersection-over-union 0.88) and similar results to manual segmentation in quantifying cortical porosity (R2 ≥ 0.97, ICC ≥ 0.98) and geometry (R2 ≥ 0.82, ICC ≥ 0.75) parameters in vivo. Furthermore, the Suppression Ratio was validated compared to established porosity protocols (R2 ≥ 0.78). Automated parameters detected age- and osteoporosis-related impairments in cortical bone porosity (P ≤ .002) and geometry (P values ranging from <0.001 to 0.08). Finally, automated porosity markers showed strong, inverse Pearson's correlations with BMD measured by pQCT (|R| ≥ 0.88) and DXA (|R| ≥ 0.76) in postmenopausal women, confirming that lower mineral density corresponds to greater porosity. CONCLUSION This study demonstrated feasibility of a simple, automated, and ionizing-radiation-free protocol for quantifying cortical bone porosity and geometry in vivo from UTE MRI and deep learning.
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Affiliation(s)
- Brandon C Jones
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, 210 South 33(rd) St, Philadelphia, PA 19104, United States of America.
| | - Felix W Wehrli
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America.
| | - Nada Kamona
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, 210 South 33(rd) St, Philadelphia, PA 19104, United States of America.
| | - Rajiv S Deshpande
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, 210 South 33(rd) St, Philadelphia, PA 19104, United States of America.
| | - Brian-Tinh Duc Vu
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, 210 South 33(rd) St, Philadelphia, PA 19104, United States of America.
| | - Hee Kwon Song
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America.
| | - Hyunyeol Lee
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America; School of Electronics Engineering, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea.
| | - Rasleen Kaur Grewal
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America.
| | - Trevor Jackson Chan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, 210 South 33(rd) St, Philadelphia, PA 19104, United States of America.
| | - Walter R Witschey
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America.
| | - Matthew T MacLean
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America.
| | - Nicholas J Josselyn
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America; Department of Data Science, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States of America.
| | - Srikant Kamesh Iyer
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America
| | - Mona Al Mukaddam
- Department of Medicine, Division of Endocrinology, Perelman School of Medicine, University of Pennsylvania, Perelman Center for Advanced Medicine, 3400 Civic Center Boulevard, Philadelphia, PA 19104, United States of America.
| | - Peter J Snyder
- Department of Medicine, Division of Endocrinology, Perelman School of Medicine, University of Pennsylvania, Perelman Center for Advanced Medicine, 3400 Civic Center Boulevard, Philadelphia, PA 19104, United States of America.
| | - Chamith S Rajapakse
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 1 Founders Building, 3400 Spruce St, Philadelphia, PA 19104, United States of America.
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Silva J, Milovic C, Lambert M, Montalba C, Arrieta C, Irarrazaval P, Uribe S, Tejos C. Toward a realistic in silico abdominal phantom for QSM. Magn Reson Med 2023; 89:2402-2418. [PMID: 36695213 PMCID: PMC10952412 DOI: 10.1002/mrm.29597] [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: 08/09/2022] [Revised: 12/18/2022] [Accepted: 01/06/2023] [Indexed: 01/26/2023]
Abstract
PURPOSE QSM outside the brain has recently gained interest, particularly in the abdominal region. However, the absence of reliable ground truths makes difficult to assess reconstruction algorithms, whose quality is already compromised by additional signal contributions from fat, gases, and different kinds of motion. This work presents a realistic in silico phantom for the development, evaluation and comparison of abdominal QSM reconstruction algorithms. METHODS Synthetic susceptibility andR 2 * $$ {R}_2^{\ast } $$ maps were generated by segmenting and postprocessing the abdominal 3T MRI data from a healthy volunteer. Susceptibility andR 2 * $$ {R}_2^{\ast } $$ values in different tissues/organs were assigned according to literature and experimental values and were also provided with realistic textures. The signal was simulated using as input the synthetic QSM andR 2 * $$ {R}_2^{\ast } $$ maps and fat contributions. Three susceptibility scenarios and two acquisition protocols were simulated to compare different reconstruction algorithms. RESULTS QSM reconstructions show that the phantom allows to identify the main strengths and limitations of the acquisition approaches and reconstruction algorithms, such as in-phase acquisitions, water-fat separation methods, and QSM dipole inversion algorithms. CONCLUSION The phantom showed its potential as a ground truth to evaluate and compare reconstruction pipelines and algorithms. The publicly available source code, designed in a modular framework, allows users to easily modify the susceptibility,R 2 * $$ {R}_2^{\ast } $$ and TEs, and thus creates different abdominal scenarios.
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Affiliation(s)
- Javier Silva
- Department of Electrical EngineeringPontificia Universidad Católica de Chile
SantiagoChile
- Biomedical Imaging CenterPontificia Universidad Católica de ChileSantiagoChile
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
| | - Carlos Milovic
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
- School of Electrical EngineeringPontificia Universidad Católica de ValparaísoValparaísoChile
| | - Mathias Lambert
- Department of Electrical EngineeringPontificia Universidad Católica de Chile
SantiagoChile
- Biomedical Imaging CenterPontificia Universidad Católica de ChileSantiagoChile
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
| | - Cristian Montalba
- Biomedical Imaging CenterPontificia Universidad Católica de ChileSantiagoChile
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
- Department of Radiology, School of MedicinePontificia Universidad Católica de ChileSantiagoChile
| | - Cristóbal Arrieta
- Biomedical Imaging CenterPontificia Universidad Católica de ChileSantiagoChile
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
| | - Pablo Irarrazaval
- Department of Electrical EngineeringPontificia Universidad Católica de Chile
SantiagoChile
- Biomedical Imaging CenterPontificia Universidad Católica de ChileSantiagoChile
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
- Institute for Biological and Medical Engineering, Pontificia Universidad Católica de ChileSantiagoChile
| | - Sergio Uribe
- Biomedical Imaging CenterPontificia Universidad Católica de ChileSantiagoChile
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
- Department of Radiology, School of MedicinePontificia Universidad Católica de ChileSantiagoChile
| | - Cristian Tejos
- Department of Electrical EngineeringPontificia Universidad Católica de Chile
SantiagoChile
- Biomedical Imaging CenterPontificia Universidad Católica de ChileSantiagoChile
- Millennium Institute for Intelligent Healthcare Engineering (iHEALTH)SantiagoChile
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