Gadolinium-DTPA enhanced MR imaging of intramuscular abscesses.

Sterile, chemical and bacterial abscesses were induced in the paraspinal muscles of 16 rats before obtaining magnetic resonance (MR) images using a 0.35-T resistive system. Abscess intensity, T1 and T2 values were recorded before and after the intravenous administration of Gd-DTPA (0.2 mmol/kg). The MR appearances of the abscesses were correlated with histologic sections. Both sterile and bacterial abscess were detected on MR images without the use of contrast medium, particularly on the T2-weighted spin echo sequence (TE/TR 56/2000 ms). However, the inflammatory zones of abscesses markedly enhanced in intensity with a corresponding decrease in T1 values after the administration of Gd-DTPA (TE/TR 28/500 ms). A clear distinction between the necrotic center and the cellular periphery of each abscesses was evident only after contrast enhancement (TE/TR 28/500 ms). Thus paramagnetic Gadolinium-DTPA was beneficial for defining the histologic components of abscesses on spin echo MR images.