Effect of gadopentetate dimeglumine on T1 signal intensity in dentate nucleus from patients with mild renal dysfunction

Objective To investigate the effect of gadopentetate dimeglumine on the T1 high signal intensity of magnetic resonance images in the dentate nucleus in patients with mild renal abnormalities. Methods Retrospective analysis was performed on 59 cases of clinical and imaging data from three or more MR enhanced scans in our hospital, measuring the average signal intensity of right dentate nucleus and right frontal white matter. The signal intensity ratio of the dentate nucleus was calculated by using the signal intensity of the right frontal white matter as the baseline. The dentate nucleus-frontal white matter signal ratios(I₀, I₁) in the first and the last two magnetic resonance examinations were compared using paired t test; independent t test was used to analyze the relationship between renal function and dentate nucleus-frontal white matter signal ratio (ΔI);Spearman test was used to analyze the correlation between the signal intensity ratio difference and the number of magnetic resonance enhancement examinations,and between the signal intensity difference and time interval between the last enhanced MR scan and the last non-enhanced scan. Multiple linear regression analysis was used to analyze the relationship between signal intensity ratio difference and age, gender, number of enhancements and time interval between the last enhanced MR scan and the last plain-scan scan. Results In the normal renal function group, I₀ was 0.892±0.098, I₁ was 0.951±0.106; in the mild renal dysfunction group, I₀ was 0.845±0.101, and I₁ was 0.949±0.121. I₁ in both groups was higher than I₀ (P<0.01). The ΔI in the normal renal function group was 0.059±0.048, and that in the mild renal dysfunction group was 0.103±0.078. The latter was larger than the former (P<0.05). In all patients, there was a positive correlation between ΔI and the number of MR enhancement scans (r=0.794, P<0.05). Further multiple linear regression analysis showed that the number of MR enhanced scans was statistically different from the first and last signal difference ΔI, the difference between the first and last signal values ΔI and age or gender showed no difference of statistical significance. Conclusions After repeated MR-enhanced scanning with gadopentetate dimeglumine (Gd-DTPA), even if the renal function is mildly abnormal60 mL·min^-1·(1.73 m²)^-1 ≤ eGFR<90 mL·min^-1·(1.73 m²)^-1, the dentate nucleus showed an increased signal on T1WI, which was significantly higher than those with normal renal function. In clinical practice, linear GBCA such as gadopentetate dimeglumine should be avoided as far as possible in patients with mild renal dysfunction..