Abstracts

RETURN TO ABSTRACT LISTING


1718. Quantification of Spinal Bone Marrow Water and Adiposity Using Three-Material Decomposition Technique on Dual-Energy CT: A Feasibility Study
Authors * Denotes Presenting Author
  1. Baojun Li *; Boston University Medical Center
  2. Ning Hua; Boston University Medical Center
  3. Janelle Li; Boston University Medical Center
  4. Carlota Andreu-Arasa; Boston University Medical Center
  5. Christina LeBedis; Boston University Medical Center
  6. Stephan Anderson; Boston University Medical Center
Objective:
To develop a novel three-material decomposition-based bone marrow fat fraction (?FF?_3MD) quantification using dual-energy CT, and investigate the feasibility to use water and fat fractions as biomarkers to diagnose and characterize osteoporotic and pathologic spinal fractures in adults.

Materials and Methods:
Bone marrow edema phantoms containing trabecular bone minerals, water, and fat were constructed using fat fractions and bone mineral density values matching those expected in healthy and edematous bone, and scanned on a GE Revolution dual-energy CT. Fat quantified by FF_3MD were compared to the reference chemical shift-based MRI proton density fat fraction (MRI-PDFF) and conventional dual-energy CT two-material decomposition-based fat fraction (FF_2MD). Subsequently, FF_3MD was applied in a retrospective, proof-of-concept pilot study including seven adults (four male and three female; average age: 60.4 y.o.; range: 23-89 y.o.) with 10 spinal fractures (six acute osteoporotic, two hemangiomas, and two metastases) imaged at the time of admission. Findings were compared to MRI or pathology.

Results:
FF_3MD showed an excellent correlation with MRI-PDFF (r=0.97,R2=0.96), compared to a moderate correlation between FF_2MD and MRI-PDFF (r=0.69,R2=0.79). Compared to FF_2MD, FF_3MD showed superior accuracy in fat quantification at the presence of confounding bone minerals (50 mg/cm3: r=1.02,R2=0.95 vs. r=0.65,R2=0.79 (p<0.01); 100 mg/cm3: r=0.81, R2=0.47 vs. r=0.21,R2=0.21 (p<0.05)). Three-material decomposition-based findings correlated well with MRI or pathology in 10/10 spinal fractures: 6/6 acute osteoporotic fractures showed increased water fraction and decreased fat fraction, 2/2 hemangioma displayed inconspicuous change in water fraction but elevated fat fraction, and 2/2 metastatic lesions also showed inconspicuous change in water fraction but conspicuously decreased fat fraction.

Conclusion:
The FF_3MD is potentially accurate in quantifying bone marrow adiposity. It is significantly more accurate and stable than FF_2MD at the presence of confounding bone minerals, when compared with MRI-PDFF. Three-material decomposition-based findings correlated well with MRI or pathology in the pilot study to diagnose and characterize osteoporotic and pathologic spinal fractures. The three-material decomposition technique makes it feasible for dual-energy CT to readily diagnose and characterize acute osteoporotic fractures and pathologic fractures with benign or metastatic lesions in the adult thoracic and lumbosacral spine in the trauma setting.