Vertebral Bone Marrow Heterogeneity Using Texture Analysis of Chemical Shift Encoding-Based MRI: Variations in Age, Sex, and Anatomical Location

Abstract

Objective: Vertebral bone marrow composition has been extensively studied in the past and shown potential as imaging biomarker for osteoporosis, hematopoietic, and metabolic disorders. However, beyond quantitative assessment of bone marrow fat, little is known about its heterogeneity. Therefore, we investigated bone marrow heterogeneity of the lumbar spine using texture analysis of chemical-shift-encoding (CSE-MRI) based proton density fat fraction (PDFF) maps and its association with age, sex, and anatomical location. Methods: One hundred and fifty-six healthy subjects were scanned (age range: 20–29 years, 12/30 males/females; 30–39, 15/9; 40–49, 5/13; 50–59, 9/27; ≥60: 9/27). A sagittal 8-echo 3D spoiled-gradient-echo sequence at 3T was used for CSE-MRI-based water-fat separation at the lumbar spine. Manual segmentation of vertebral bodies L1-4 was performed. Mean PDFF and texture features (global: variance, skewness, kurtosis; second-order: energy, entropy, contrast, homogeneity, correlation, sum-average, variance, dissimilarity) were extracted at each vertebral level and compared between age groups, sex, and anatomical location. Results: Mean PDFF significantly increased from L1 to L4 (35.89 ± 11.66 to 39.52 ± 11.18%, p = 0.017) and with age (females: 27.19 ± 6.01 to 49.34 ± 7.75%, p < 0.001; males: 31.97 ± 7.96 to 41.83 ± 7.03 %, p = 0.025), but showed no difference between females and males after adjustment for age and BMI (37.13 ± 11.63 vs. 37.17 ± 8.67%; p = 0.199). Bone marrow heterogeneity assessed by texture analysis, in contrast to PDFF, was significantly higher in females compared to males after adjustment for age and BMI (namely contrast and dissimilarity; p < 0.031), demonstrated age-dependent differences, in particular in females ( p < 0.05), but showed no statistically significant dependence on vertebral location. Conclusion: Vertebral bone marrow heterogeneity, assessed by texture analysis of PDFF maps, is primarily dependent on sex and age but not on anatomical location. Future studies are needed to investigate bone marrow heterogeneity with regard to aging and disease.

Texture Analysis Using CT and Chemical Shift Encoding-Based Water-Fat MRI Can Improve Differentiation Between Patients With and Without Osteoporotic Vertebral Fractures

“…Water-fat separation was performed using a graph-cut algorithm, employing a multi-peak fat model specific to bone marrow and a single T2* decay model ( 49 , 50 ). The PDFF maps were computed as the ratio of the fat signal over the sum of fat and water signals ( 29 , 51 , 52 ). T2* maps were extracted in addition to PDFF maps.…”

“…The vertebral bodies were manually segmented using sagittal images. In the reconstructed maps, manual polygonal ROIs were carefully placed to enclose the vertebral body using MITK ([ ]; German Cancer Research Center, Division of Medical and Biological Informatics, Medical Imaging Interaction Toolkit, Heidelberg, Germany; Figures 1 and 3 ) ( 51 , 52 ). The segmentations did not include the posterior elements and were performed by the same radiologist who had also performed visual inspection of the results of the CNN-based algorithm for CT data processing (two years of experience in spine imaging, M.D.).…”

“…On the basis of the distribution of gray-level values, texture analysis was used to characterize structural image properties of predefined regions by quantifying different texture features (37)(38)(39). Texture analysis was performed using the segmentation masks derived from CT and CSE-MRI enclosing single vertebral bodies, and different first-order statistical moments from global gray-level histograms, second-order features based on the graylevel co-occurrence matrix (GLCM), and higher-order features based on the gray-level run-length matrix (GLRLM) were extracted (Figure 1 and Table 1) (40,41,51,(53)(54)(55).…”

Survey of MRI Usefulness for the Clinical Assessment of Bone Microstructure

“…CSE-MRI conducted in 156 subjects at 3T (8 echoes 3D spoiled gradient echo sequence, voxel size 0.98 mm × 0.98 mm × 4.00 mm, acq. time 1:17 min), showed that vertebral bone marrow heterogeneity is primarily dependent on sex and age but not on anatomical location suggesting that future studies should investigate the bone marrow heterogeneity with regards to aging and disease [ 141 ]. Baum et al in a study conducted on the whole spine of 28 young and healthy patients using CSE-MRI at 3T (8 echoes, acq.…”

Association of Thigh Muscle Strength with Texture Features Based on Proton Density Fat Fraction Maps Derived from Chemical Shift Encoding-Based Water–Fat MRI

“…Regarding musculoskeletal imaging, TA has predominantly been performed on non-quantitative data, such as sonography [ 26 ], computed tomography [ 27 ], or conventional T2-weighted MRI sequences [ 28 , 29 ]. Furthermore, TA based on CSE-MRI-derived PDFF maps has been used in the quantitative analysis of vertebral bone marrow [ 30 , 31 ]. In this regard, PDFF-based TA can be considered superior in its ability to reveal information on muscular fat distribution and consequently differentiate muscles with different patterns of fatty infiltration.…”