3D MRI with CT-like bone contrast (3D-BONE): a pictorial review of clinical applications

BackgroundComputed tomography (CT) is the gold standard imaging modality for the assessment of 3D bony morphology but incurs the cost of ionizing radiation exposure. High-resolution 3D magnetic resonance imaging (MRI) with CT-like bone contrast (CLBC) may provide an alternative to CT in allowing complete evaluation of both bony and soft tissue structures with a single MRI examination.PurposeTo review the technical aspects of an optimized stack-of-stars 3D gradient recalled echo pulse sequence method (3D-Bone) in generating 3D MR images with CLBC, and to present a pictorial review of the utility of 3D-Bone in the clinical assessment of common musculoskeletal conditions.Material and Methods3D-Bone is a black-bone imaging technique for acquiring high-resolution 3D MR images with strong CLBC, achieved by first rendering as high a signal as possible from non-cortical bone tissues, and second by minimizing signal contrast between non-cortical bone tissues.Results3D-Bone can be used in the clinical evaluation of bony morphology in common musculoskeletal conditions. Advantages include strong bone-soft tissue contrast, resistance to motion artefacts, simple hardware and software requirements, and straightforward image processing. Disadvantages include non-specificity for cortical bone, sensitivity to susceptibility artefacts, a lack of quantitative tissue measurements, as well as overall lower image resolution and bone-soft tissue contrast compared to CT.ConclusionThe use of 3D MRI pulse sequences providing CLBC such as 3D-Bone could potentially offer complete clinical evaluation of bony morphology and soft tissues with a single MRI study for certain clinical indications, negating the need for ionizing radiation exposure from CT and reducing costs.