Effect of contrast dilution on contrast-enhanced MR angiography of the aorta and renal arteries

Abstract

The aim of this study was to investigate the effect of gadolinium chelate dilution on vascular enhancement in contrast-enhanced two-dimensional (2D) MR subtraction angiography of aorta and renal arteries. Twenty patients were prospectively included. 2D subtraction MR angiography consisted of successive multisection breathhold GRE acquisitions of 16 s (2D FLASH, TR/TE 72/4, flip angle 60 degrees) obtained in the coronal plane before and after intravenous bolus administration of 0.1 mmol/kg BW gadolinium chelate. Patients underwent both diluted and undiluted gadolinium chelate administration in a random order. The data were studied both qualitatively and quantitatively on source and maximum intensity projection images. The length of renal arteries opacified was found not to differ significantly according to contrast dilution. The contrast enhancement percentage was not significantly modified according to the dilution used, but the time to peak enhancement was observed to be longer with the diluted contrast. Qualitatively, the best MR images were those obtained when undiluted contrast was injected first (chi2, P = 0.01). At a dosage of gadolinium chelate 0.1 mmol/kg BW, undiluted contrast 2D MR subtraction angiography seems to be more appropriate for studying diseases of the aorta and renal arteries than a similar diluted dose.

Dose optimization of contrast-enhanced carotid MR angiography

“…Apparently, the dose increase from 0.1 to 0.2 mmol/kg bodyweight does not provide better image quality or higher contrast enhancement in the carotids. Our findings are in agreement with those of similar studies [10,12,14,15], most of which were realized with volunteers. No significant difference between a single dose, a double dose and a triple dose was found in CE-MRA of the aorta with respect to quantitative signal enhancement and qualitative interpretation [10].…”

“…Despite the success of CE-MRA, only a few studies have addressed the question of optimal gadolinium dose [4,[7][8][9][10][11][12][13][14] comparing various dose groups for the renal [4] or major abdominal arteries [8,10,[12][13][14]. Most authors have tried to address the question by measuring peak enhancement for volunteers [10,[12][13][14][15], but only a few studies have compared the quantitative contrast enhancement within patients [14].…”

“…Most authors have tried to address the question by measuring peak enhancement for volunteers [10,[12][13][14][15], but only a few studies have compared the quantitative contrast enhancement within patients [14].…”

Renal Functional Contrast-Enhanced Magnetic Resonance Imaging

“…12,32 Approximately 70 to 90 seconds after administration of a full dosage of Gd-DOTA, we observed a significant decrease of SI within inner medulla and renal pelvis, which was also noted on time-intensity curves. 6,[33][34][35][36][37] In those studies, an assumption was made that the relationship between SI and the tissue concentration of the contrast agent was unaffected by changes of T2 and T2*, allowing conversion of arbitrary SI curves into quantitative units using the inverse relationship between T1 and concentration of contrast agent. 9 This phenomenon is presumably related to the contributed T2 and T2* effects found at levels of contrast-agent concentration above a given threshold, as previously reported 6 and supported by the results of our phantom study (25 mmol Gd/ L Ϫ1 for Gd-DOTA and 3.5 mmol Gd/L Ϫ1 for P792).…”

Is half‐dose contrast‐enhanced three‐dimensional MR angiography sufficient for the abdominal aorta and pelvis?

“…However, Goyen et al (11) reported that the image quality of CE‐3D‐MRA using 1.0 mol/L gadolinium chelate showed no statistically significant improvement compared to using 0.5 mol/L gadolinium chelate, and suggested that the concentration of gadolinium chelate might have little effect upon image quality. Dilution is thus one alternative for reducing the total dose of gadolinium chelate, but to our knowledge there have been few reports evaluating the effect of gadolinium chelate dilution on vascular enhancement in CE‐3D‐MRA (12).…”