Comparison of FSE T2 W PROPELLER and 3D–FIESTA of 3 T MR for the internal auditory canal

Abstract

ObjectiveThe study compared the use of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique fast spin echo (FSE) T2 W and the sequence of three-dimensional fast imaging employing steady-state acquisition (3D–FIESTA) technique in the MRI of the internal auditory canal for overall image quality improvement. Materials and methodsOne hundred thirty-two patients undergoing FSE T2 W PROPELLER and 3D–FIESTA examinations of the internal auditory canal were included. All examinations were performed at 3.0 T with comparison of a sagittal oblique FSE T2 W sequence with the PROPELLER technique to 3D–FIESTA in the same reconstructed orientation with PROPELLER. Image quality was evaluated by two radiologists using a 4-point scale. The Wilcoxon signed rank test was used to compare the data of the two techniques. ResultsThe image quality of FSE T2 W PROPELLER was significantly improved compared to the reconstructed images of 3D–FIESTA. Observer 1: median FSE T2 W with PROPELLER, 4 [mean, 3.455] versus median reconstructed 3D–FIESTA, 3 [mean, 3.15], (P<.001); Observer 2: median FSE T2 W with PROPELLER, 4 [mean, 3.47] versus median reconstructed 3D–FIESTA, 3 [mean, 3.25], (P<.001). Interobserver agreement was good (k value, 0.73) for the rating of the overall image quality. ConclusionThe FSE T2 W PROPELLER technique for MRI of internal auditory canal reduced uncertainty caused by motion artifact and improved the quality of the image compared to the reconstructed 3D–FIESTA. It was affected by different parameters including the blade width, echo train length (ETL). This is explained by data oversampling at the center region of k-space, which requires additional imaging time over conventional MRI techniques. Increasing blade was expected to improve motion correction effects but also the signal-to-noise ratio. ETL increases the image sharpness and the overall image quality.