1 All authors: Department of Radiology, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, CH-1211 Geneva, Switzerland.
AJR Am J Roentgenol. 2014 Apr;202(4):W357-64. doi: 10.2214/AJR.13.11145.
The purpose of this study was to evaluate the diagnostic performance of a dedicated dual-source dual-energy MDCT (DECT) protocol for the detection of urothelial tumors.
A DECT protocol including furosemide and split-bolus contrast injection was used in 69 consecutive patients with suspected abnormalities of the urinary system. Thirteen patients were excluded because there was no follow-up available. In 56 patients, the final diagnosis was proven with endoscopy, biopsy, or follow-up and included urothelial tumors (n = 37) in 16 patients, other urinary tract pathologies (n = 9) in eight patients, and absence of lesions of the collecting system in 32 patients. The image series consisted of a dual-energy true unenhanced series, 35-second arterial phase, and 8-minute nephrographic-excretory phase and were analyzed retrospectively. True enhancement of all detected lesions was measured. On the basis of the DECT data of the contrast-enhanced images, virtual unenhanced series were created and iodine concentration was calculated using commercially available software. The attenuation difference between virtual unenhanced and contrast-enhanced images (virtual enhancement) was measured. CT findings were compared with the final diagnosis.
Urothelial tumors were identified on 35-second series, 8-minute series, and both series combined, with sensitivity of 91.9% (95% CI, 78.1-98.2%), 83.4% (68.0-93.8%), and 97.3% (85.8-100%), respectively. Urothelial tumors showed stronger virtual enhancement (p = 0.02) and higher iodine concentration (p = 0.03) than lesions of other origin. Distinction between urothelial tumors and nontumoral lesions was possible with sensitivity of 91.9% (78.1-98.2%) when using a threshold concentration of at least 1.0 mg I/mL.
Dual phase DECT with virtual unenhanced imaging and iodine concentration measurement appears to be a useful diagnostic test for urothelial tumors.
本研究旨在评估专用双源双能 MDCT（DECT）方案检测尿路上皮肿瘤的诊断性能。
对 69 例疑似泌尿系统异常的患者使用包括呋塞米和双份对比剂注射的 DECT 方案。13 例患者因无随访而被排除。在 56 例患者中，最终诊断通过内窥镜检查、活检或随访证实，包括 16 例患者的尿路上皮肿瘤、8 例患者的其他尿路病变和 32 例患者的集合系统无病变。图像系列包括双能真实未增强系列、35 秒动脉期和 8 分钟肾排泄期，并进行回顾性分析。测量所有检测到的病变的真实增强。基于增强图像的 DECT 数据，创建虚拟未增强系列，并使用商业可用软件计算碘浓度。测量虚拟未增强和增强图像之间的衰减差异（虚拟增强）。将 CT 结果与最终诊断进行比较。
在 35 秒系列、8 分钟系列和两个系列的组合上，尿路上皮肿瘤的检出率分别为 91.9%（95%CI，78.1-98.2%）、83.4%（68.0-93.8%）和 97.3%（85.8-100%）。与其他来源的病变相比，尿路上皮肿瘤显示出更强的虚拟增强（p=0.02）和更高的碘浓度（p=0.03）。当使用至少 1.0mg I/mL 的阈值浓度时，通过虚拟增强和碘浓度测量进行双期 DECT 可实现对尿路上皮肿瘤的 91.9%（78.1-98.2%）的敏感区分。
双能 CT 双期检查结合虚拟未增强成像和碘浓度测量，似乎是一种有用的诊断尿路上皮肿瘤的方法。
