3D contrast-enhanced MR angiography of the pelvis and lower extremities with subtraction method. Study of vascular delineation

By the application of dynamic contrast enhanced MR imaging with use of a phased-array multicoil, excellent angiographic images can be obtained. With use of a phased-array coil, however, increased signal from subcutaneous fat may obscure the visualization of vessels. Subtraction is an effective method to suppress signals from background tissue. We evaluated the value of contrast enhanced three-dimensional high-speed gradient echo subtraction magnetic resonance angiographic imaging on a 1.5 T MR unit with evaluation of clinical data. The effect of image resolution on vessel visualization by phantoms was also evaluated. With the subtraction technique, smaller peripheral vessels were clearly visualized in comparison with the results of non-subtraction techniques. In order to obtain high resolution images, a higher signal-to-noise ratio was required. (author)