THE USE OF GADOLINIUM-BOPTA ON MAGNETIC-RESONANCE-IMAGING IN BRAIN INFECTION

RATIONALE AND OBJECTIVES. The use of gadolinium (Gd)-BOPTA as a magnet ic resonance contrast agent for central nervous system disease was stu died in a canine brain abscess model. METHODS. A Streptococcus faecali s brain abscess was evaluated in five dogs at 1.5 T. Imaging was perfo rmed during the late cerebritis stage, at 5 to 7 days after surgery. M agnetic resonance scans were acquired before and at 1, 5, 15, 30, 45, and 60 minutes after contrast administration, using a dose of 0.1 mmol /kg, Scans also were acquired both before and after contrast injection with the implementation of magnetization transfer. RESULTS. Lesion en hancement, quantified by region-of-interest measurement, peaked at 5 m inutes after contrast injection, Both the increase in lesion enhanceme nt from 1 to 5 minutes after injection and the decrease from 5 to 15 m inutes after injection, although small, were statistically significant (P < 0.004 and P < 0.03, respectively), The application of magnetizat ion transfer improved lesion enhancement, as measured by signal differ ence/noise, by 39%. This result also was statistically significant (P < 0.001). CONCLUSIONS. In intraparenchymal brain infection, Gd-BOPTA p rovides effective lesion enhancement when used at a dose of 0.1 mmol/k g, Further research is needed to compare the magnitude of enhancement achieved with Gd-BOPTA, which has weak protein binding and both hepato biliary and renal excretion, with that with Gd chelates, which have pu re renal excretion.