探讨光谱CT虚拟平扫(VNC)在泌尿系结石CT尿路造影（CTU）检查中的应用价值。

回顾性分析50例行CTU检查的患者，所有患者按正常流程行CTU，然后用后处理工作站重建获得虚拟平扫图像，采用自身对照，将虚拟平扫和常规增强图像分为一组，真实平扫和常规增强图像作为对照组，比较两组图像平扫中肾皮质及腹主动脉的CT值及信噪比（SNR），由两位高年资诊断医师评估图像并对图像质量评分，并计算结石检出率。

虚拟平扫与真实平扫在图像质量上差异无统计学意义，均能满足诊断要求，其中虚拟平扫组平均评分为3.7分，真实平扫组平均评分为4分。虚拟平扫感兴趣区（ROI）的平均CT值略高于真实平扫ROI的平均CT值，虚拟平扫ROI处的SNR也高于真实平扫（P<0.05）。在结石检出率上，虚拟平扫组对2 mm以上结石检出率与真实平扫一致，2 mm以下结石检出率也达到了真实平扫组的87%。如采用虚拟平扫替代真实平扫，患者受到的有效辐射剂量可以减少约1/4，约为7.8 mSv。

光谱CT虚拟平扫在CTU中有较高的应用价值，其图像质量高，能减少对患者的辐射剂量。

To explore the application value of spectral detector CT virtual non-contrast in CTU of urinary calculi.

Clinical datas of fifty patients with urinary calculi were retrospectively analyzed. All patients completed the examination according to the routine procedure, and then get the VNC images by the workstation. Virtual plain scan and conventional enhanced images were divided into a group, real plain scan and conventional enhanced images were divided into the control group. Then the CT values and signal-to-noise ratio (SNR) of renal cortex and abdominal aorta of two groups were compared. Finally, two senior diagnosises evaluated the quality of the images and calculated the stone detection rate.

There was no significant difference in image quality and the detection rate of stone between VNC and real plain scan, and the images can be satisfied for the requirement of diagnosis. The average score of the virtual plain scan group was 3.7, and the average score of the real plain scan group was 4.0. The average CT value of the region of interest (ROI) was slightly higher than the average of the ROI of the real plain scan, and the SNR of the ROI of virtual plain scan was also higher than that of real plain scan (P<0.05). In terms of the detection rate of stones, the detection rate of stones under 2 mm in the virtual plain scan group was consistent with that of the real plain scan group, and the detection rate of stones under 2 mm in the virtual plain scan group reached 87% as in the real plain scan group. If virtual plain scan was instead of real plain scan, the effective radiation dose received by patients can be reduced nearly 25%, about 7.8 mSv.

Spectral CT virtual plain scan has high application value in CTU, the image quality is high, and it can reduce the radiation dose for patients.