Gadolinium contrast medium administration does not adversely affect T2*-weighted gradient recalled echo magnetic resonance imaging of the canine brain at 1.5 Tesla.

Abstract

As gadolinium-based contrast agents are paramagnetic and have T2 shortening effects, they have the potential to adversely affect gradient recalled echo sequences. The aim of this prospective, cross-sectional study was to evaluate the effects of gadolinium administration on T2*-weighted sequence diagnostic quality and signal intensity when imaging the canine brain. A total of 100 dogs underwent brain magnetic resonance imaging (MRI) including pre- and postcontrast T2*-weighted sequences acquired with a delay (Group A) or immediately (Group B) following gadolinium administration. Pre- and postcontrast images were subjectively compared. In dogs with intracranial enhancing masses, regions of interest were drawn on corresponding images and signal intensity ratios were calculated. The effect of degree and pattern of contrast enhancement, susceptibility artifacts, and time between contrast injection and T2*-weighted sequence acquisition on signal intensity ratio was evaluated. Overall 31 dogs had contrast enhancing intracranial masses. Subjectively, there was no difference in image quality of T2*-weighted sequences obtained before and after contrast medium administration. No significant signal intensity differences of intracranial contrast enhancing masses were found (Group A P=0.9999; Group B P=0.9992). Susceptibility artifacts did not differ in appearance, and there was no effect on calculated signal intensity ratio (P=0.8142). Similarly, there was no effect of degree of enhancement or contrast heterogeneity on signal intensity ratio (P=0.4413). No correlation was found between signal intensity ratio and the time to acquisition (P=0.199). Administration of gadolinium-based MRI contrast agents does not adversely affect T2*-weighted imaging of the brain in dogs at 1.5T even in the presence of contrast enhancing lesions.