螺旋CT仿真结肠内窥镜检查前的准备与操作方法

Significance of preparation and operation of CT virtual colonoscopy imaging

目的:探讨CT扫描前准备及扫描时的体位对CT仿真结肠镜(CTVC)成像成功的影响。方法:对106例临床疑有大肠病变的患者行双体位CTVC检查,检查前进行充分准备,检查中采取灵活多变的注气方式,数据采集后进行工作站后处理,分别获得结肠、直肠的CT仿真内镜(CTVE)、表面遮面显示(SSD)、容积再现(VR)等三维图像,由2名医生盲法对图像质量进行评价。结果:106例中,81例70岁以下的患者肠道准备良好,全结肠无粪渣或积有少量清澈的液体,充气良好,肠腔内表面结构显示清晰,图像质量佳;20例70岁以上的患者因体质问题,肠道准备及图像质量较差,对诊断有一定影响;5例70岁以上的患者不能很好配合护士注气工作,患者随注气随排气,充气量不足,导致肠腔内表面结构被覆盖或显示不清,图像质量差,不能诊断。结论:CTVC能重建出空腔脏器内壁的立体图像,动态的回放其图像如同纤维内窥镜所见。相对于纤维结肠镜检查来说,CT检查的优点是方便、安全、痛苦少。做好术前肠道准备和正确操作的方法是此项检查成败的关键。

[Abstract] Objective： To explore the effect of the preparation before scanning and the posture during scanning on CT virtual colonoscopy（CTVC）. Methods： 106 patients with clinically suspected colorectal lesions underwent CTVC examination by supine and prostrate.Full preparations were made before the examination. The skilly operations of gas-enema injection were made during the examination. Postprocessing was made after data acquisition by multi-detector spiral CT, colon and rectum respectively, There -dimension images were acquired including CT virtual endoscopy （CTVE）, surface screen display （SSD）, volume rendering（VR） image. Imaging quality was evaluated by two radiologists blindly. Results： Among 106 patients,81 patients under70 years old, whose bowel preparations were fully, total colectomy without feces or product of a small amount of clear liquid, the intraluminal surface structures were clearly displayed. Imaging qualities were good. In 20 patients over70 years old,whose bowel preparations were not fully, imaging qualities were poor to influence diagnosis in some degree. In 5 patients over70 years old,whose preparation were poor, gas injection with exhaust,aeration quantities were insufficient, the intraluminal surface structures were covered or unclearly displayed. Imaging qualities were bad to result in diagnostic failure of CTVC imaging. Conclusion： CTVC volume scanning data were postprocessed through the CT workstation software ,which could acquire the stereo images of the inner wall in the hollow organ and dynamic playback of the image, such as fibroscopy. Compared with fibrocolonoscopy, CT has the advantages such as low risk of causing colonic hole, convenient, and less painful. Full preparations and skilly operations are key factors to assure success of CTVC. [Key words] Multi-slice spiral CT; X-ray computed; Image processing; Virtual endoscopy; Posture