Accuracy of Contrast-Enhanced Dual-Energy MDCT for the Assessment of Iodine Uptake in Renal Lesions

作者：Mileto Achille^*; Marin Daniele; Ramirez Giraldo Juan Carlos; Scribano Emanuele; Krauss Bernhard; Mazziotti Silvio; Ascenti Giorgio

来源：American Journal of Roentgenology, 2014, 202(5): W466-W474.

DOI：10.2214/AJR.13.11450

• dual-energy CT
• iodine
• uptake
• iodine quantification
• iodine-related attenuation
• renal cell carcinoma
• renal lesions

OBJECTIVE. The objective of our study was to assess the accuracy of iodine-related attenuation and iodine quantification as imaging biomarkers of iodine uptake in renal lesions on a single-phase nephrographic image with dual-energy MDCT. %26lt;br%26gt;MATERIALS AND METHODS. Fifty-nine patients (41 men, 18 women; age range, 28-84 years) with 80 renal lesions underwent contrast-enhanced dual-energy CT during the nephrographic phase of enhancement. Renal lesions were characterized as enhancing or non-enhancing on color-coded iodine overlay maps using iodine-related attenuation (in Hounsfield units) and iodine quantification (in milligrams per milliliter). For iodine-related attenuation the iodine uptake thresholds of 15 and 20 HU were tested; a threshold of 0.5 mg/mL was used for iodine quantification. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of iodine-related attenuation and iodine quantification were calculated from chi-square tests of contingency with histopathology or imaging followup as the reference standard. The 95% CIs were calculated from binomial expression. Differences in sensitivity and specificity were assessed by means of McNemar analysis. %26lt;br%26gt;RESULTS. A significant difference in sensitivity and specificity was found between iodine-related attenuation with the thresholds of 15 HU (sensitivity, 91.4%; specificity, 93.3%; PPV, 91.4%; NPV, 93.3%) and 20 HU (sensitivity, 77.1%; specificity, 100%; PPV, 100%; NPV, 84.9%) (p = 0.008) and between iodine quantification (sensitivity, 100%; specificity, 97.7%; PPV, 97.2%; NPV, 100%) and iodine-related attenuation with a threshold of 20 HU (p = 0.004). No significant difference in sensitivity and specificity was found between iodine quantification and iodine-related attenuation with a threshold of 15 HU. %26lt;br%26gt;CONCLUSION. Contrast-enhanced dual-energy MDCT with iodine-related attenuation and iodine quantification allows accurate evaluation of iodine uptake in renal lesions on a single-phase nephrographic image.

• 出版日期2014-5