[MR angiography of the carotid arteries using 3D TOF technique with sagittal double-volume acquisition using a new head-neck coil]

Use of magnetic resonance angiography to select candidates with recently symptomatic carotid stenosis for surgery: systematic review

OBJECTIVE

To determine if sufficient evidence exists to support the use of magnetic resonance angiography as a means of selecting patients with recently symptomatic high grade carotid stenosis for surgery.

DESIGN

Systematic review of published research on the diagnostic performance of magnetic resonance angiography, 1990-9.

MAIN OUTCOME MEASURES

Performance characteristics of diagnostic test.

RESULTS

126 potentially relevant articles were identified, but many articles failed to examine the performance of magnetic resonance angiography as a diagnostic test at the surgical decision thresholds used in major clinical trials on endarterectomy. 26 articles were included in a meta-analysis that showed a maximal joint sensitivity and specificity of 99% (95% confidence interval 98% to 100%) for identifying 70-99% stenosis and 90% (81% to 99%) for identifying 50-99% stenosis. Only four articles evaluated contrast enhanced magnetic resonance angiography.

CONCLUSIONS

Magnetic resonance angiography is accurate for selecting patients for carotid endarterectomy at the surgical decision thresholds established in the major endarterectomy trials, but the evidence is not very robust because of the heterogeneity of the studies included. Research is needed to determine the diagnostic performance of the most recent developments in magnetic resonance angiography, including contrast enhanced techniques, as well as to assess the impact of magnetic resonance angiography on surgical decision making and outcomes.

Lower extremity occlusive disease: diagnostic imaging with a combination of cardiac-gated 2D phase-contrast and cardiac-gated 2D time-of-flight MRA

PURPOSE

The goal of this work was to test the ability of a combination of 2D phase-contrast MR angiography (2D-PC-MRA) and triggered 2D time-of-flight MRA (2D-TOF-MRA) in comparison to intraarterial digital subtraction angiography (DSA) to correctly diagnose the location and shape of occlusive lesions in the iliac and femoral arteries and to determine whether 2D-TOF-MRA is helpful to clarify questionable lesions demonstrated by 2D-PC-MRA.

METHODS

In 50 patients with claudication, 2D-PC-MRA was performed in three consecutive coronal positions from the aortic bifurcation to below the trifurcation. Axial 2D-TOF-MRA was performed additionally at the site of detected lesions of >50% and lesions in doubt to obtain more precise information about the stenosis. Lesions were classified as follows: low grade occlusion, <50%; high grade occlusion, >50%. MRA was performed within 24 h of a DSA examination.

RESULTS

In all patients, the arterial tree from the aortic bifurcation to the trifurcation could be visualized. One hundred twelve lesions were detected by MRA. Sensitivity was 96% and specificity was 92%. Sixty-two lesions were classified as high grade occlusion and reevaluated. In this category, sensitivity was 100% and specificity was 96%.

CONCLUSION

The combination of 2D-PC-MRA with triggered 2D-TOF-MRA detects stenotic lesions in the lower extremity arterial system with high sensitivity and specificity.