Department of Radiology, New York University Langone Medical Center, 550 First Ave, HW 202, New York, NY 10016, USA.
AJR Am J Roentgenol. 2011 Jun;196(6):W693-700. doi: 10.2214/AJR.10.5541.
The purpose of this study was to validate the utility of dual-source dual-energy MDCT in quantifying iodine concentration in a phantom and in renal masses.
A series of tubes containing solutions of varying iodine concentration were imaged with dual-source dual-energy MDCT. Iodine concentration was calculated and compared with known iodine concentration. Single-phase contrast-enhanced dual-source dual-energy MDCT data on 15 patients with renal lesions then were assessed independently by two readers. Dual-energy postprocessing was used to generate iodine-only images. Regions of interest were placed on the iodine image over the lesion and, as a reference, over the aorta, for recording of iodine concentration in the lesion and in the aorta. Another radiologist determined lesion enhancement by comparing truly unenhanced with contrast-enhanced images. Mixed-model analysis of variance based on ranks was used to compare lesion types (simple cyst, hemorrhagic cyst, enhancing mass) in terms of lesion iodine concentration and lesion-to-aorta iodine ratio.
In the phantom study, there was excellent correlation between calculated and true iodine concentration (R(2) = 0.998, p < 0.0001). In the patient study, 13 nonenhancing (10 simple and three hyperdense cysts) and eight enhancing renal masses were evaluated in 15 patients. The lesion iodine concentration and lesion-to-aorta iodine ratio in enhancing masses were significantly higher than in hyperdense and simple cysts (p < 0.0001).
Iodine quantification with dual-source dual-energy MDCT is accurate in a phantom and can be used to determine the presence and concentration of iodine in a renal lesion. Characterization of renal masses may be possible with a single dual-source dual-energy MDCT acquisition without unenhanced images or reliance on a change in attenuation measurements.
本研究旨在验证双源双能 MDCT 定量计算碘浓度的能力，该方法适用于在体模和肾肿块中。
采用双源双能 MDCT 对含有不同碘浓度溶液的一系列管进行成像。计算碘浓度并与已知碘浓度进行比较。然后，两名观察者分别对 15 例有肾病变的患者单相增强双源双能 MDCT 数据进行评估。采用双能量后处理生成仅含碘的图像。在病变部位和主动脉（作为参考）上放置感兴趣区，以记录病变和主动脉中的碘浓度。另一位放射科医生通过比较真实未增强与增强图像来确定病变增强。采用基于秩的混合模型方差分析比较不同病变类型（单纯囊肿、出血性囊肿、强化肿块）的病变碘浓度和病变与主动脉碘比值。
在体模研究中，计算碘浓度与真实碘浓度之间具有极好的相关性（R(2) = 0.998，p < 0.0001）。在患者研究中，对 15 例患者的 13 个非增强（10 个单纯性囊肿和 3 个高密度囊肿）和 8 个增强性肾肿块进行了评估。增强性肿块的病变碘浓度和病变与主动脉碘比值明显高于高密度囊肿和单纯性囊肿（p < 0.0001）。
双源双能 MDCT 定量碘浓度在体模中准确，可用于确定肾病变中碘的存在和浓度。通过单次双源双能 MDCT 采集而无需进行未增强图像或依赖于衰减测量变化，即可对肾肿块进行特征描述。
