联合双层探测器光谱CT单能量图及碘图诊断肾脏实性肿瘤

Combined Application of Monoenergetic Images and Iodine Maps Derived from Dual-layer Spectral Detector CT for the Diagnosis of Solid Renal Tumors

目的 评价双层探测器光谱CT(DL-SDCT)虚拟单能量图像(VMI)和碘图在肾脏实性肿瘤诊断中的应用价值。方法 回顾性分析77例肾脏实性肿瘤增强CT影像资料,获得皮髓质交界期常规CT图像、VMI、碘图和VMI-碘图融合图,测量各组图像中肿瘤、肌肉和肾皮质的CT值、碘密度值(ID)和图像噪声值,计算对比噪声比(CNR)、相对强化值(REV)和标准化碘密度(NID)。采用5分法分别评价图像质量。结果 相比于常规图像,VMI图像噪声值更低,且CNR值更高(P均<0.001)。VMI-碘图融合图的主观评分最高。DL-SDCT定量参数REV及NID均可用于透明细胞癌的诊断。结论 DL-SDCT的VMI、碘图及其融合图的图像质量优于常规CT,有助于肾脏实性肿瘤的细节显示和定性诊断。

Objective To evaluate the value of dual detector spectral CT(DL-SDCT) virtual monoenergetic images(VMIs) and iodine maps in the diagnosis of solid renal tumors. Methods The enhanced CT images of 77cases with solid renal tumors were retrospectively analyzed. The conventional CT images,VMIs,iodine maps and VMI-iodine maps fused images were obtained. The CT value,iodine density(ID) and image noise value of tumor,muscle and renal cortex in each group were measured,and the contrast-to-noise ratio(CNR),relative enhancement value(REV) and normalized iodine density(NID) were calculated.The image quality was evaluated by 5-point method. Results Compared with conventional images,VMI images had lower noise and higher CNR(all P<0.001). The subjective score of VMI-iodine maps fused images was the highest. Both DL-SDCT quantitative parameters REV and NID could be used in the diagnosis of clear cell carcinoma. Conclusion Compared with conventional CT images,the image quality of VMI,iodine maps and their fusion images derived from DL-SDCT are superior,which is helpful for the detailed display and qualitative diagnosis of solid renal tumors.