Comparison of 2D- and 3DFT multiple overlapping thin-slab acquisition TOF MR angiography in carotid disease

We intended to compare two-dimensional Fourier transform (2DFT) with three-dimensional Fourier transform (3DFT) multiple overlapping thin-slab acquisition (MOTSA) time-of-flight (TOF) magnetic resonance angiography for percent diameter stenosis, length of stenosis, and apparent occlusion at the carotid bifurcation. For that, 101 symptomatic patients (n = 202 carotid bifurcations) were evaluated with 3DFT MOTSA TOF and 2DFT TOF. Three observers measured the percent diameter stenosis from oblique axial multiplanar reformatted (MPR) images and length of stenosis from maximum intensity projection (MIP) images. Kappa analysis assessed interobserver agreement and the Wilcoxon signed rank test was used to compare the two MR angiographic techniques. There was a significant difference in the percent diameter stenosis (p < 0.01) and length of carotid stenosis (p < 0.01) between 2DFT and 3DFT MOTSA TOF magnetic resonance angiography. Stenosis was greater in 33% of carotid arteries and was upgraded (NASCET) in 17% of carotid arteries on the 2DFT TOF. The number of apparently occluded carotid arteries was equal with both MRA techniques. There was good agreement between the three observers (k = .50).