Increased T1 Signal Intensity of the Anterior Pituitary Gland on Unenhanced Magnetic Resonance Images After Chronic Exposure to Gadodiamide

Objective The aim of this study was to assess the signal intensity of the anterior pituitary (AP) gland on unenhanced T1-weighted images in patients with history of serial intravenous injections of gadodiamide and normal renal function. Materials and Methods We included 53 patients who had undergone at least 5 injections of gadodiamide and a control group of 15 subjects who underwent at least 5 brain magnetic resonance imaging without gadolinium-based contrast agents. Using unenhanced sagittal T1-weighted images, values of mean signal intensity of the AP and of the central pons were obtained. Anterior pituitary–to–pons signal intensity ratios were calculated dividing the values of the AP by those of the pons. Then, the ratios were compared between the first and the last magnetic resonance imaging scans for all the subjects. To assess the difference between the first and the last ratios, nonparametric Wilcoxon signed-rank test with Monte Carlo resampling was applied. A P value less than 0.05 was considered as statistically significant. Results The comparison between the first and the last scan revealed a statistically significant increase of AP-to-pons ratio in the last scan for the gadolinium-exposed group (P
Source: Investigative Radiology - Category: Radiology Tags: Original Articles Source Type: research