Evaluating Marrow Signal Intensity: Comparison of T1 FLAIR and T1 FSE Images

The purpose of the study was to determine whether there is a difference in the appearance of the marrow signal intensity on T1 FLAIR and T1 FSE images, and if so, whether the difference is related to age. T1 FLAIR and T1 FSE sequences, obtained prospectively in 93 patients, were compared after excluding patients older than 75 years, and patients with a history of prior lumbar surgery, or a predisposing medical condition, e.g. HIV disease, multiple myeloma, osteoporosis, metastatic disease, renal failure or severe degenerative disease. All studies were performed on a 1.5 T GE Signa/Excite. All case pairs were reviewed by three board certified radiologists, each with more than five years experience in MR imaging. Regardless of age, where a difference was perceived, the T1 FLAIR image was judged darker in 88% of patients. In order to avoid misdiagnoses and/or additional unnecessary exams, it is important to recognize that marrow signal intensity may appear artificially low in normal individuals.