A comparison of pulse sequences in the detection of post-traumatic bone marrow abnormalities at low field strength MRI

Abstract 

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 abnormalities was established in 20 of 141 patients on the basis of decreased signal intensity on T1-weighted SE and GRE sequences and increased signal intensity on T2-weighted TSE and fat-suppressed IRGE sequences. Signal changes within the bone marrow were evaluated and statistically correlated with normal bone. Results. The highest signal alteration was found on T1-weighted SE and GRE sequences, followed by IRGE, which detected smaller differences in signal intensity. T2-weighted TSE imaging showed the least contrast. The areas with bone marrow changes were 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 SE, T1-weighted GRE and IRGE sequences were most effective 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 bone bruise, a protocol including GRE and IRGE pulse sequences could be most beneficial.