Single-dose breath-hold gadolinium-enhanced three-dimensional MR angiography of the renal arteries

PURPOSE: To evaluate the quality of single-dose breath-hold three-dimension al (3D) magnetic resonance (MR) angiography of the renal arteries optimized with a 1-mL test bolus timing examination. MATERIALS AND METHODS: Three-dimensional spoiled gradient-echo imaging (3.8 -4.2/1.3-1.7 [repetition time msec/echo time msec], 25 degrees-40 degrees f lip angle) was performed in 60 patients after administration of gadopenteta te dimeglumine (average dose, 0.11 mmol/kg). Synchronization of contrast ma terial administration with data acquisition was achieved with a 1-mL test d ose of contrast material to estimate patient circulation parameters. Image quality was assessed by using;contrast-to-noise (CNR), relative vascular en hancement, and venous-to-arterial enhancement ratios and subjective scoring of arterial and venous enhancement. The effect of the contrast material in jection rate and the influence of breath holding during the timing examinat ion also were examined. RESULTS: Overall, of 60 studies, 58 were diagnostic and 56 demonstrated exc ellent arterial enhancement. Venous enhancement was seen in eight studies. The average aortic relative vascular enhancement (+/- SD) was 14.6 +/- 5.9, with an aorta-to-inferior vena cava (IVC) CNR of 69.7 +/- 43.9. The IVC-to -aorta venous-to-arterial enhancement ratio averaged 0.08 +/- 0.16. There w as no significant difference in image quality based on injection rates or t he performance of breath holding during the timing examination (P > .1). CONCLUSION: Breath-hold gadolinium-enhanced renal MR angiography free of ve nous enhancement can be performed consistently and reliably with 20 mL of c ontrast material when studies are synchronized to patient circulation time by using a timing examination.