Gadofosveset-enhanced thoracic MR venography: a comparative study evaluating steady state imaging versus conventional first-pass time-resolved dynamic imaging.

ABSTRACT

Background Dedicated blood-pool contrast agents combined with optimal angiographic protocols could improve the diagnostic accuracy of thoracic magnetic resonance angiography (MRA). Purpose To assess the clinical utility of Gadofesveset-enhanced imaging and compare an optimized steady-state (SS) sequence against conventional first-pass dynamic multi-phase (DMP) imaging. Material and Methods Twenty-nine patients (17 men, 12 women; mean age = 42.7, age range = 18-72 years) referred for MR thoracic venography were recruited. Imaging was performed on a 1.5T MRI system. A blood-pool contrast agent (Gadofesveset) was administered intravenously. Thirty temporal phases were acquired using DMP. This was immediately followed by a high-resolution SS sequence. Three radiologists in consensus reviewed seven thoracic vascular segments after randomizing the acquisition order. Image quality, stenoses, thromboses, and artifacts were graded using a categorical scoring system. The image quality for both approaches was compared using Wilcoxon's signed-rank test. McNemar's test was used to compare the proportions of stenosis grades, thrombus and artifacts. Results SS had significantly better image quality than DMP (3.14 ± 0.73 and 2.92 ± 0.60, respectively; P < 0.001). SS identified fewer stenoses (>50%) than DMP; the differences in stenosis categorizations was statistically significant ( P = 0.013). There was no significant difference in the proportions of vessels with thromboses ( P = 0.617). DMP produced more artifacts than SS (101 versus 85); however, the difference was not statistically significant ( P = 0.073). Conclusion Gadofesveset-enhanced thoracic angiography is clinically feasible. SS imaging produces better image quality and fewer artifacts than conventional DMP imaging.