3-T Contrast-Enhanced MR Angiography in Evaluation of Suspected Intracranial Aneurysm: Comparison with MDCT Angiography

Abstract

The purpose of this study was to prospectively evaluate a high-spatial-resolution contrast-enhanced 3-T MR angiography protocol for detection and characterization of intracranial aneurysms and to compare the results with those of MDCT angiography. Forty-one patients with suspected intracranial aneurysm underwent high-spatial-resolution 3D contrast-enhanced MR angiography and CT angiography (CTA). With a generalized autocalibrating partially parallel acquisition algorithm with an acceleration factor of 4 at 3 T, contrast-enhanced MR angiographic images were acquired over 20 seconds with a spatial-resolution of 0.7 x 0.7 x 0.8 mm. CTA images were acquired with a spatial resolution of 0.35 x 0.35 x 0.8 mm on a 16-MDCT scanner in 17 seconds. The images from the two studies were evaluated independently by two neuroradiologists for image quality, presence of aneurysm, and characterization of aneurysm. The dimensions of the aneurysm were measured independently with both techniques. A total of 25 aneurysms were identified with both contrast-enhanced MR angiography and CTA. A comparative analysis of detection and depiction of aneurysms showed excellent interobserver agreement for both contrast-enhanced MR angiography (kappa = 0.81) and CTA (kappa = 0.91) images. There was significant correlation between the techniques for both qualitative assessment of aneurysm depiction (rho = 0.92; 95% CI, 0.88-0.95) and quantitative dimensional measurement of aneurysm size (r = 0.94; 95% CI, 0.92-0.97). Contrast-enhanced MR angiography at 3 T is reliable for evaluation and characterization of intracranial aneurysms. The results are comparable with those of MDCTA.