Bone marrow imaging using STIR at 0.5 and 1.5 T.

We retrospectively examined MR images in 82 patients to evaluate the usefulness of short inversion time inversion recovery (STIR) in bone marrow imaging at 0.5 and 1.5 T. The study included 56 patients at 1.5 T and 26 patients at 0.5 T with a variety of pathologic bone marrow lesions (principally oncological), and compared the contrast and image quality of STIR imaging with spin-echo short repetition time/echo time (TR/TE), long TR/TE, and gradient-echo sequences. The pulse sequences were adjusted for optimal image quality, contrast, and fat nulling. STIR appears especially useful for the evaluation of red marrow (e.g., spine), where contrast between normal and infiltrated marrow is greater than with either gradient-echo or T1-weighted images. STIR is also extremely sensitive for evaluation of osteomyelitis, including soft tissue extent. In more peripheral (yellow) marrow, T1-weighted images are usually as sensitive as STIR. Limitations of STIR include artifacts, in particular motion artifact that at high field strength necessitates motion compensation. At 0.5 T, however, motion compensation is usually not necessary. Also, because of extreme sensitivity to water content, STIR may overstate the margins of a marrow lesion. With these limitations in mind, STIR is a very effective pulse sequence at both 0.5 and 1.5 T for evaluation of marrow abnormalities.