High-Resolution, Contrast-Enhanced Magnetic Resonance Angiography With Elliptical Centric k-Space Ordering of Supra-aortic Arteries Compared With Selective X-Ray Angiography

Abstract

Background and Purpose-The objective of this study was to evaluate the relative value of high-resolution, contrastenhanced MR angiography (CE MRA) with elliptical centric k-space ordering compared with intra-arterial x-ray angiography for imaging carotid stenosis. Methods-Thirty patients with suspected stenosis of the carotid arteries were examined with CE MRA (1.5-T scanner) and x-ray angiography (aortic arch survey and selective imaging of both common carotid arteries). For the first time, not only the extracranial carotid bifurcation but all the vessel segments from the aortic arch to the circle of Willis were assessed by independent investigators. Results-For the internal carotid artery in the region of the extracranial carotid bifurcation, there was a very close correlation between CE MRA and x-ray angiography (sensitivity, 100%; specificity, 92%). The initially suspected overestimation of stenosis on CE MRA in 3 cases was ultimately revealed to be an underestimation on x-ray angiography. CE MRA showed slightly poorer imaging of the basal vessel segments at the level of the aortic arch (because of breathing artifacts) and the intracranial vessel segments (because of small vessel caliber and venous superimposition due to delayed sequence starts). Conclusions-The MRA technique described here provides reliable results in the diagnosis of carotid stenosis and is thus suitable for replacing the invasive conventional x-ray angiography method in most cases. Further technical developments with regard to spatial resolution are still required for improved visualization of small vessels (terminal carotid branches and intracranial vessels).

Diagnostic Accuracy of Magnetic Resonance Angiography for Internal Carotid Artery Disease

“…Of these papers, 37 TOF MRA 17,18,26 -60 and 21 CE MRA papers 16,26,27,33,35,37,[61][62][63][64][65][66][67][68][69][70][71][72][73][74][75] fulfilled the inclusion criteria (Tables 1 and 2). Of the TOF papers, 11 used 2D TOF MRA, 14 used 3D TOF MRA, and 12 included both 2D and 3D TOF data (Table 1).…”

MRI of atherosclerosis in clinical trials

“…It has been shown that 3D TOF angiography produces superior quality of carotid arteriograms as compared to 2D TOF or phase-contrast sequences (45). Ultrafast 3D gradient-echo sequences with elliptic-centric phase encoding represent the method of choice for acquisition in the first-pass contrast-enhanced MRA (46,47). For black blood imaging, the 3D approach can potentially provide important benefits, such as a reduction of slice thickness and an increased SNR.…”

Comparison of Carotid Plaque Ulcer Detection Using Contrast-Enhanced and Time-of-Flight MRA Techniques

“…Moreover, TOF-MRA is usually acquired through the carotid bifurcation only and with a higher spatial resolution, as CE-MRA is typically optimized for coverage from the aortic arch to the skull base, and this may enhance the ability of TOF-MRA to detect small ulcers. Despite these merits, TOF-MRA is often inadequate for detecting tandem lesions 15,16,18 and is prone to saturation of slowly flowing or recirculating blood protons, resulting in signal loss within a severely compromised lumen or the carotid bulb, respectively. 19,20 Recirculating blood proton saturation could also affect the signal within an ulcer crater.…”