A COMPARISON OF PULSE SEQUENCES IN THE DETECTION OF POSTTRAUMATIC BONE-MARROW ABNORMALITIES AT LOW-FIELD STRENGTH MRI

Objective and patients. One hundred and forty-one patients with recent joint trauma, aged 12-71 years, were imaged on a 0.2-T dedicated MRI system and, evaluated for bone bruises. The most beneficial sequences were compared. Design. The diagnosis of post-traumatic bone marrow abn ormalities was established in 20 of 141 patients on the basis of decre ased signal intensity on T1-weighted SE and GRE sequences and increase d signal intensity on T2-weighted TSE and fat-suppressed IRGE sequence s. Signal changes within the bone marrow were evaluated and statistica lly correlated with normal bone. Results. The highest signal alteratio n was found on T1-weighted SE and GRE sequences, followed by IRGE, whi ch detected smaller differences in signal intensity, T2-weighted TSE i maging showed the least contrast. The areas with bone marrow changes w ere approximately equal in size on T1-weighted SE and T2-weighted TSE sequences. The same areas depicted on IRGE and GRE sequences proved to be significantly larger (P<0.01). Conclusion. Using a 0.2-T dedicated system T1-weighted SEI T1-weighted CRE and IRGE sequences were most e ffective in detecting conspicuous bone marrow alteration, while the T2 -weighted TSE sequence was inferior. GRE and IRGE imaging showed areas about 4 times larger depicting bone marrow changes. On suspicion of b one bruise, a protocol including GRE and IRGE pulse sequences could be most beneficial.