Hepatic Lesions: Improved Image Quality and Detection with the Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction Technique-Evaluation of SPIO-enhanced T2-weighted MR Images

Purpose: To evaluate the effectiveness of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique for superparamagnetic iron oxide (SPIO)-enhanced T2-weighted magnetic resonance (MR) imaging with respiratory compensation with the prospective acquisition correction (PACE) technique in the detection of hepatic lesions. Materials and Methods: The institutional human research committee approved this prospective study, and all patients provided written informed consent. Eighty-one patients (mean age, 58 years) underwent hepatic 1.5-T MR imaging. Fat-saturated T2-weighted turbo spin-echo images were acquired with the PACE technique and with and without the PROPELLER method after administration of SPIO. Images were qualitatively evaluated for image artifacts, depiction of liver edge and intrahepatic vessels, overall image quality, and presence of lesions. Three radiologists independently assessed these characteristics with a five-point confidence scale. Diagnostic performance was assessed with receiver operating characteristic (ROC) curve analysis. Quantitative analysis was conducted by measuring the liver signal-tonoise ratio (SNR) and the lesion-to- liver contrast-to-noise ratio (CNR). The Wilcoxon signed rank test and two-tailed Student t test were used, and P < .05 indicated a significant difference. Results: MR imaging with the PROPELLER and PACE techniques resulted in significantly improved image quality, higher sensitivity, and greater area under the ROC curve for hepatic lesion detection than did MR imaging with the PACE technique alone (P < .001). The mean liver SNR and the lesion-to- liver CNR were higher with the PROPELLER technique than without it (P < .001). Conclusion: T2-weighted MR imaging with the PROPELLER and PACE technique and SPIO enhancement is a promising method with which to improve the detection of hepatic lesions.