静脉膀胱造影CT仿真内窥镜的实验和临床应用研究

CT virtual endoscopy of intravenous cystography: experimental study and clinical application

目的 探讨静脉膀胱造影CT仿真内窥镜 (CTVE)成像技术的可行性 ,并与空气CTVE成像技术比较 ,评价其临床应用价值。方法 (1 )应用相同的扫描条件对充盈不同浓度的高密度对比剂 (将 76 %的泛影葡胺稀释成 1 / 8,1 / 1 2 ,1 / 1 6 ,1 / 32 ,1 / 4 8,1 / 64 ,1 / 1 2 8)、水、空气的直肠内模拟隆起性病变行螺旋CT容积扫描 ,经工作站软件处理获得CTVE图像 ,相互间进行比较 ;(2 )对 30例患者 ,经肘静脉注射对比剂 30min后行膀胱CT容积扫描 ,亦经软件处理获得膀胱CTVE图像 ,并与纤维膀胱镜和手术结果对照。结果 (1 )以不同浓度高密度对比剂和空气为对比剂进行三维重建均可获得清晰的CTVE图像 ,以水作对比剂未能重建出满意的CTVE图像。 (2 )不同浓度的高密度对比剂之间及其与空气之间重建出的CTVE图像整体差异有显著性意义 (F =1 59 95 ,P <0 0 5) ,较低浓度高密度对比剂 (1 / 32～ 1 / 1 2 8)重建出的CTVE图像对直径 2～ 3mm的病灶显示较好 ;对直径 5mm及其以上的病灶各组间则差异无显著性意义。 (3)静脉膀胱造影 2 6例获得满意的CTVE图像 ,能显示输尿管内口 ,检出病灶直径最小者为 3mm。 2例CTVE图像欠佳 ,2例未重建出CTVE图像。结论高密度对比剂CTVE成像能达到空气CTVE成像同等效果 。

Objective To evaluate the feasibility of CT virtual endoscopy (CTVE) of intravenous cystography, and to assess its clinical application by comparing it with the CTVE of air cystography. Methods (1) The pig colon with simulated mass lesions was scanned by spiral CT at the same parameters (pitch of 5/3, a table speed of 5 mm/s, 1.3 mm reconstruction intervals, 50 mA, 120 kV) after filled with Urografin of various concentrations (76% Urografin diluted to 1/8, 1/12, 1/16, 1/32, 1/48, 1/64, 1/128), water, and air, respectively. The volume scan data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with each other. (2) Spiral CT scan was carried out preoperatively in 30 patients with a delay of 30 minutes after intravenous injection of contrast medium. The data were also transferred to the workstation and reconstructed. The results were compared with the fiber optic cystoscopic and/or operative findings. Results (1) The CTVE images of the Urografin and air cystography were successfully reconstructed, but not of water. (2) There was statistically significant differences in total among the CTVE images of different groups ( F =159.95, P <0.05); The CTVE images from concentrations of 1/32-1/128 were better than those from concentrations of 1/8-1/16 and air in the detection of mass lesions with diameter of 2-3 mm, however, there were more mild artifacts seen on the former. There was no significant differences in detecting mass lesions≥5 mm among the groups. (3) The CTVE images of intravenous cystography were obtained satisfactorily in 26 patients. The normal membrane of urinary bladder and ureteric orifices were clearly showed. The detected diameter of the smallest mass lesion of the bladder was 3 mm. The CTVE images were faint in 2 cases and not obtained in 2 cases, respectively. Conclusion The quality of CTVE images of intravenous cystography can be equal to that of air cystography, and the former is expected to replace the latter, and thus providing a noninvasive technique for the examination of bladder.