MRI Quantification of Composition Marrow
What is it?
The traditional means of examining bone marrow is invasive, requiring samples to be obtained by biopsy and aspiration. Magnetic Resonance Imaging (MRI) has however been recognised for some time as the non-invasive imaging modality of choice in diagnosing bone marrow disorders and the age-related changes in marrow composition have been qualitatively assessed. However, relatively few MRI studies have reported quantitative measurements of bone marrow composition, inferring relative red and yellow composition from their respective water and fat signal contributions. This is typically done using MR spectroscopy (MRS) whereby the fat and water signal can be acquired from a region of interest (ROI), studies to date focussing on a single lumbar vertebra.
We have recently reported quantitative measurements of bone marrow composition using MRS at both central and peripheral skeletal sites in asymptomatic subjects of varying ages, along with a novel image analysis technique that provides a detailed composition map, that has been scientifically validated in a phantom study. Increased fat fraction with osteoporosis has been confirmed by MRS in both female and male subjects, although this may simply reflect replacement of bone tissue by fatty marrow tissue.
MR Images & Spectra: Central Lumbar Spine and Peripheral Calcaneus