胃部疾病:CT仿真胃镜与电子胃镜对比的实验研究

Comparison of CT Virtual Gastroscopy with Elctronic Gastroscopy: An Experimental Study

目的 探讨胃部疾病模型的制作方法和CT仿真胃镜 (CTVG)对这些病变的显示能力。材料与方法 取离体猪胃 (胃底部有 1个憩室 ) 1只 ,制作 6个直径 5～ 14mm大小的隆起性“病变”和 5个长径 6～ 8mm、深径 1～1.5mm的凹陷性“病变”。同时行CT/MR仿真胃镜、电子胃镜和双对比造影检查。结果 空气充盈法CTVG检出了所有 6个隆起性“病变”和 5个凹陷性“病变”中的 3个 ;一个 40mm× 6 0mm的憩室、一个螺旋管接头准确显示。阳性对比剂充盈法CTVG显示了 6个隆起性“病变”中的 5个 ,所有凹陷性“病变”(憩室除外 )未检出。MR仿真胃镜结果类似阳性对比剂充盈法CTVG。气钡双重造影仅显示较大的 3个隆起性“病变” ,电子胃镜检出了所有模拟“病变”。胃隆起性“病变”在CTVG上随阈值而变化并与胃腔改变同步、一致 ;胃内异物如螺旋管接头 ,在CTVG上也随阈值而变化 ,但与胃腔改变不同步、不一致。结论 仿真胃镜是可选择的胃部疾病内镜成像检查的无创性方法 ,以空气充盈法CTVG的图像质量为佳 ;阈值数值改变时 ,CTVG所示胃腔与“病变”变化的协调性有助于判定“病变”来源和鉴别诊断。

Objective To explore the preparation of gastric lesions in pig's stomach, and to evaluate CT virtual gastroscopy (CTVG) in displaying the lesions. Materials and Methods Six simulated protrusion lesions with a diameter of 5～14mm and 5 simulated caved ulcerative lesions with a length of 6～8mm and a depth of 1～1.5mm were created in a fresh isolated pig stomach which carried a diverticulum. CTVR, MR virtual gastroscopy (MRVG), electronic gastroscopy and double contrast radiography were performed.Results With air insufflation of the stomach, CTVG detected all 6 protrusion lesions and 3 of the 5 caved lesions. Besides, the diverticulum and the head of the spiral catheter were also clearly demonstrated on CTVG. When the stomach was filled with positive contrast media (3% Gd DTPA), only 5 protrusion lesions and no caved lesions were detected on CTVG, and similar results were obtained in MRVG. On double contrast GI, only 3 big protrusion lesions could be displayed. Electronic gastroscopy revealed all simulated lesions. On CTVG, the shape of the protrusion lesions was changing, in pace with the change of gastric cavity, with the adjusting of the threshold value. Conclusion As a non invasive technique, CTVG, with air insufflation of the stomach, can provide high quality images. The coordination between gastric cavity and lesion's morphology with the adjusting of CTVG threshold value is helpful for the determination of the lesion's origin.