Magnetic resonance angiography

The field of MRA has progressed to a stage at which several clinical applications are of obvious value, including the diagnosis of cerebral aneurysms, venous disorders and disease of the carotid bifurcation. Additionally spin echo images are useful in studying the parenchyma and this together with MRA works to be an excellent diagnostic package in the presurgical workup of patients with cerebral vascular abnormalities. With further technical improvements, it seems likely that important applications of MRA will also be found in the diagnosis of peripheral artery disease, stenosis of the renal artery and ischemic heart disease. With the advent of fast imaging techniques like echoplanar imaging, the ability image the coronary and renal arteries accurately seems possible in the near future. At present, however the lack of optimal spatial resolution and the presence of flow artifacts precludes the use of this technique for imaging the vasculature with an accuracy comparable with conventional angiography. The advent for contrast 3-D CT angiography has resulted in a technique of studying the intracranial vessels immediately after assessing for the presence of subarachnoid hemorrhage. It is superior to MRA in demonstrating the actively filling and thrombused portions of giant, partially thrombused aneurysms and in planning the surgical approach in relation to bony landmarks. Though there are daunting obstacles, with continuous ongoing clinical research and the added inputs from a dramatically changing computer technology, MRA is all set to be an imaging study of great promise that may eventually replace diagnostic catheter angiography in most clinical situations.