Intra-individual comparison of different gadolinium-based contrast agents in the quantitative evaluation of C6 glioma with dynamic contrast-enhanced magnetic resonance imaging.

This experiment aimed to compare the ionic (Gadodiamide, Gd-DTPA-BMA) and non-ionic (Gadopentetate dimeglumine, Gd-DTPA) gadolinium-based contrast agents (GBCA) in the quantitative evaluation of C6 glioma with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). A C6 glioma model was established in 12 Wistar rats, and magnetic resonance (MR) scans were performed six days after tumor implantation. Imaging was performed using a 3.0-T MR scanner with a 7-inch handmade circular coil. Pre-contrast T1 mapping and dynamic contrast-enhanced T1WI after a bolus injection (0.2 mL s) of GBCA at 0.4 mmol kg were performed. Each rat received two DCE-MRI scans, 24 h apart. The first and second scans were performed using Gd-DTPA-BMA and Gd-DTPA, respectively. Image data were processed using the Patlak model. Both K and V maps were generated. Tumors were manually segmented on all 3D K and V maps. Pixel counts and mean values were recorded for use in a paired t-test. Three radiologists independently performed the tumor segmentation and value calculation. The agreements from different observers were subjective to the intra-class correlation coefficient (ICC). Readers demonstrated that the pixel counts of tumors in K maps were higher with Gd-DTPA-BMA than with Gd-DTPA (P<0.001, all readers). Although the K values were higher with Gd-DTPA-BMA than with Gd-DTPA, there was no statistical significance (P>0.05, all readers). The pixel counts of tumors in V maps, as well as V values, showed no obvious difference between the two agents (P>0.05, all readers). Excellent interobserver measurement reproducibility and reliability were demonstrated in the ICC tests. The Gd-DTPA-BMA contrast agent had significantly higher pixel counts of glioma in the K maps, and an increased tendency for average K values, indicating that DCE-MRI with Gd-DTPA-BMA may be more suitable and sensitive for the evaluation of glioma.