利用对比增强双能 CT 尿路造影术获得的物质特异性图像检测和描述尿路结石。

Detection and characterization of urinary stones using material-specific images derived from contrast-enhanced dual-energy CT urography.

机构信息

Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, PR China.

Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, PR China.

出版信息

Br J Radiol. 2023 Dec;96(1152):20230337. doi: 10.1259/bjr.20230337. Epub 2023 Oct 24.

DOI:10.1259/bjr.20230337

PMID:37750853

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10646646/

Abstract

OBJECTIVE

To determine the accuracy of material-specific images derived from contrast-enhanced dual-energy CT urography (DECTU) in detecting and measuring urinary stones in comparison with that of unenhanced images and its utility in calcified stone differentiation.

METHODS

105 patients with 202 urinary stones (121 had confirmed composition by infrared spectroscopy) underwent triphasic (unenhanced, portal venous (VP) and excretory phase (EP)) DECTU. Material-specific images were derived in VP and EP with calcium-water, calcium-iodine and CaOxalate_Dihydrate (COD)-Hydroxyapatite (HAP) as basis material pairs. Stone number and size were recorded on unenhanced images and VP and EP material-specific images, where stone densities were also measured. Material densities of calcified stones (pure calcium oxalate [pCaO, = 34], mixed calcium oxalate [mCaO, = 14], mixed carbonate phosphate [mCaP, = 70]) were compared and thresholds for differentiating these stones were determined using receiver operating characteristic analysis.

RESULTS

All 202 urinary stones were detected on the unenhanced, calcium (water) and calcium (iodine) images in VP. While the detection rate was significantly decreased to 58 and 64% using calcium (water) and calcium (iodine) images in EP, respectively (all < 0.001). Stone sizes measured on calcium (iodine) images in VP was similar to that of unenhanced images (10.6 10.7 mm, > 0.05). Significant differences in material densities were found among pCaO, mCaO and mCaP on COD(HAP) images with AUC of 0.72-0.74 for differentiating these stones.

CONCLUSION

Material-specific images in VP derived from DECTU allow reliably detecting and measuring urinary tract stones in comparison with unenhanced images and can identify calcified stones with moderate diagnostic performance to provide potential 33% dose reduction.

ADVANCES IN KNOWLEDGE

Material-specific images, especially the calcium (iodine) images in VP allow for reliable detection of urinary stones.Stone size measurement should be performed on the calcium (iodine) images in VP.Material density measurements on COD-HAP (VP) material decomposition images can be used to differentiate among pure calcium oxalate, mixed calcium oxalate and mixed carbonate phosphate stones with AUC of 0.72-0.74.

摘要

目的

通过对比增强双能 CT 尿路造影（DECTU）的物质特异性图像与非增强图像，确定其在检测和测量尿路结石方面的准确性，并评估其在区分钙化结石方面的效用。

方法

105 例 202 颗尿路结石患者（121 例经红外光谱证实结石成分）行三期（非增强、门静脉（VP）和排泄期（EP））DECTU。在 VP 和 EP 中，以钙水、钙碘和 CaOxalate_Dihydrate（COD）-Hydroxyapatite（HAP）为基础物质对，生成物质特异性图像。在非增强图像和 VP 和 EP 的物质特异性图像上记录结石数量和大小，并测量结石密度。比较钙化结石（纯草酸钙[ pCaO，=34]、混合草酸钙[ mCaO，=14]、混合碳酸磷灰石[ mCaP，=70]）的物质密度，并通过受试者工作特征分析确定区分这些结石的阈值。

结果

所有 202 颗尿路结石在非增强、钙（水）和钙（碘）VP 图像上均能被检测到。而在 EP 中，使用钙（水）和钙（碘）图像的检出率分别显著下降至 58%和 64%（均<0.001）。VP 中钙碘图像上测量的结石大小与非增强图像相似（10.6±10.7mm，>0.05）。在 COD（HAP）图像上，pCaO、mCaO 和 mCaP 之间的物质密度差异有统计学意义，其区分这些结石的 AUC 为 0.72-0.74。