Türk Osteoporoz Dergisi (Dec 2018)
Diffusion and Chemical Shift Magnetic Resonance Imaging Properties of Lumbar Bone Marrow; Correlation with Osteoporosis
Abstract
Objective:To investigate whether or not diffusion-weighted imaging (DWI) of vertebral bone marrow or dual-echo chemical shift imaging (CSI) achieved by magnetic resonance imaging (MRI) can be used in the diagnosis of osteoporosis.Materials and Methods:Twenty-nine postmenopausal women patients (mean age 53.9±9 years) who underwent upper abdominal MRI and dual-energy X-ray absorptiometry (DXA) were included in the study retrospectively. A total of 87 lumbar vertebras which appropriate were divided into subgroups as normal, osteopenic and osteoporotic according to T-scores. Apparent diffusion coefficient (ADC) values were calculated from DWI and signal intensities (SI) that measured in T1 dual-echo sequences were compared between groups. The fat fractions of the vertebral body were measured based on the signal intensity index and vertebral spleen ratio (VSR) formulas previously used for adrenal adenomas.Results:The mean vertebral ADC values were 0.61±0.1 x 10-3 mm2/s in the normal group, 0.59±0.1 x 10-3 mm2/s in the osteopenic group, and 0.56±0.1 x 10-3 mm2/s in the osteoporotic group and there was no significant difference between them. The SI in out-of-phase sequence, SI index, and VSR were able to discriminate the osteoporotic group that had sustained fracture risks from the healthy and osteopenic ones. The sensitivities of the out-of-phase SI, SI index and VSR were 65.2%, 61.1% and 71%, respectively, while their specificities were 61.1%, 63.8%, and 61.1%, respectively.Conclusion:The diffusion properties of bone marrow are not fully affected by osteoporosis. The DXA scores appear to be moderately related to the chemical composition of bone marrow rather than its cellularity. CSI based fat quantification can be a referrer in the decision to initiate treatment by giving an idea of the presence of osteoporosis
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