Objective: To determine the clinical feasibility of contrast-enhanced three-dimensional (3D) MR angiography (MRA) with fat suppression spectral inversion at lipids and to compare subtracted and nonsubtracted images. Material and Methods: In 13 patients suspected of having lower extremity ischemia, 3D dynamic contrast-enhanced MRA of the iliac and femoral arteries was performed using the fat suppression technique. The validity of the MRA interpretations of the degree of stenoses was evaluated by comparing with conventional angiography as the gold standard. The contrast-to-noise (C/N) ratios of both subtracted and nonsubtracted maximum-intensity-projection (MIP) images were calculated. Results: In the arteries with stenosis of 50% or greater, the sensitivity and specificity of the subtracted MR angiograms were 100% and 96.5%, respectively, not significantly different from the correponding values in nonsubtracted MRAs (100% and 94.1%, respectively). The C/N ratios of the subtracted images were significantly higher than those of the nonsubtracted images ( p<0.001). Conclusion: With this technique, fat suppression can be performed with only a slight increase in the examination time. A lower dose of contrast material can be used in MRA with fat suppression than without it. Subtracted MRA improves the ease of interpretation compared to nonsubtracted MRA.
Application of direct virtual coil to dynamic contrast-enhanced MRI and MR angiography with data-driven parallel imaging
