Contrast-enhanced magnetic resonance angiography in stroke diagnostics: additional information compared with time-of-flight magnetic resonance angiography?

PURPOSE

The aim of this study was a comparison of the diagnostic value of time-of-flight magnetic resonance angiography (TOF-MRA) and contrast-enhanced (CE) MRA in the setting of acute stroke MRI. The hypothesis was that CE-MRA has at least the same diagnostic value as the commonly used TOF-MRA.

MATERIALS AND METHODS

A total of 66 stroke patients underwent MRI up to 24 h after symptom onset and again after 3–6 days. Primary slices and maximum intensity projections (MIP) of both techniques were evaluated separately and in combination by two readers in consensus. The quality of imaging and degree of vascular pathologies were evaluated.

RESULTS

Out of 109 examinations 105 could be evaluated. There were no significant differences in imaging quality in normal vascular segments. For arterial segments distal to an occlusion CE-MRA allowed better visualization of vessels than TOF-MRA. A combined evaluation of both techniques allowed a significantly better assessment than evaluation of images by one technique alone. In contrast to TOF-MRA, CE-MRA included extracranial segments.

CONCLUSION

CE-MRA and TOF-MRA do not differ regarding the evaluation of normal intracranial vessels. CE-MRA provides the advantage of good visualization of vessels distal to occluded segments. Furthermore CE-MRA allows visualization of extracranial vessels and faster image acquisition. TOF-MRA can be equivalently used if the administration of contrast agents is not possible.