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Background: View-sharing (VS) increases spatiotemporal resolution in dynamic contrast-enhanced (DCE) MRI by sharing high-frequency k-space data across temporal phases. This temporal sharing results in respiratory motion within any phase to propagate artifacts across all shared phases. Compressed sensing (CS) eliminates the need for VS by recovering missing k-space data from pseudorandom undersampling, reducing temporal blurring while maintaining spatial resolution.Purpose: To evaluate a CS reconstruction algorithm on undersampled DCE-MRI data for image quality and hepatocellular carcinoma (HCC) detection.Study Type: Retrospective.Subjects: Fifty consecutive patients undergoing MRI for HCC screening (29 males, 21 females, 52-72 years).Field Strength/sequence: 3.0T MRI. Multiphase 3D-SPGR T1 -weighted sequence undersampled in arterial phases with a complementary Poisson disc sampling pattern reconstructed with VS and CS algorithms.Assessment: VS and CS reconstructions evaluated by blinded assessments of image quality and anatomic delineation on Likert scales (1-4 and 1-5, respectively), and HCC detection by OPTN/UNOS criteria including a diagnostic confidence score (1-5). Blinded side-by-side reconstruction comparisons for lesion depiction and overall series preference (-3-3).Statistical Analysis: Two-tailed Wilcoxon signed rank tests for paired nonparametric analyses with Bonferroni-Holm multiple-comparison corrections. McNemar's test for differences in lesion detection frequency and transplantation eligibility.Results: CS compared with VS demonstrated significantly improved contrast (mean 3.6 vs. 2.9, P < 0.0001) and less motion artifact (mean 3.6 vs. 3.2, P = 0.006). CS compared with VS demonstrated significantly improved delineations of liver margin (mean 4.5 vs. 3.8, P = 0.0002), portal veins (mean 4.5 vs. 3.7, P < 0.0001), and hepatic veins (mean 4.6 vs. 3.5, P < 0.0001), but significantly decreased delineation of hepatic arteries (mean 3.2 vs. 3.7, P = 0.004). No significant differences were seen in the other assessments.Data Conclusion: Applying a CS reconstruction to data acquired for a VS reconstruction significantly reduces motion artifacts in a clinical DCE protocol for HCC screening.Level Of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:984-993. [ABSTRACT FROM AUTHOR]

BACKGROUND. Extrinsic warming of iodinated CT contrast media to body temperature reduces viscosity and injection pressures. However, studies examining the effect of extrinsic warming on clinical adverse events are limited in number and provide conflicting results. Therefore, consensus practice recommendations have been sparse. OBJECTIVE. The purpose of this study is to compare rates of extravasation, allergic and allergiclike reactions, and physiologic reactions between iohexol 350 mg I/mL warmed to body temperature (37°C) versus this agent maintained at room temperature. METHODS. This retrospective study compared adult patients who received CT examinations using IV iohexol 350 that had either been warmed to body temperature or maintained at room temperature. At our institution, contrast media had historically been warmed to body temperature before a protocol change unrelated to this investigation. Information on the patient and CT examination was extracted from the electronic medical record. Adverse events, including extravasations, allergic and allergiclike reactions, and physiologic reactions, were compared between groups. RESULTS. A total of 3939 patients received contrast media warmed to body temperature before the protocol change; 3933 patients received contrast media at room temperature after the protocol change. The body temperature group experienced 11 (0.28%; 95% CI, 0.14-0.50%) adverse events, all extravasations; the allergic and allergic-like reaction rate was 0.00% (97.5% CI, 0.00-0.09%). The room temperature group experienced 17 (0.43%; 95% CI, 0.25-0.69%) adverse events: 13 (0.33%; 95% CI, 0.17-0.56%) extravasations and four (0.10%; 95% CI, 0.03-0.26%) allergic and allergiclike reactions. No physiologic reaction occurred in either group. The two groups were not different in terms of overall reaction rate ( p = .19), extravasation rate ( p = .69), allergic and allergiclike reaction rate ( p = .06), or physiologic reaction rate ( p > .99). Logistic regression adjusting for patient and CT characteristics (age, sex, conventional CT vs CTA, contrast media volume, injection location) showed no significant association of patient group and adverse reaction rate (odds ratio, 2.19; 95% CI, 0.68-7.00). Multivariable regression modeling showed an excess of 0.27 adverse events per 100 patients within the room temperature group, which is below a 0.6% noninferiority margin. CONCLUSION. The data suggest that maintaining iohexol 350 at room temperature is noninferior to warming the agent to body temperature before injection. CLINICAL IMPACT. The resources involved to prewarm iohexol 350 before injection may not be warranted.