スキルス胃癌の特徴と診断の基本―CTの立場から

CT Imaging Features of Scirrhous Gastric Cancer

要旨　スキルス胃癌のCT診断について，術前に化学療法などが併用されていない外科手術症例37例について，術前のCT所見と，手術および病理所見とを対比し，スキルス胃癌の局所所見（浸潤範囲ならびに深達度診断），リンパ節転移診断について検討した．CTについては通常行われている経静脈造影剤投与を用い，ダイナミック撮像や，水やガスなどによる胃内腔の伸展は行なわなかった．

　CT images of scirrhous gastric cancer were reviewed in 37 patients to reveal CT image features of the tumor. Iodine-based contrast material was intravenously administrated without use of the bolus technique. No additional techniques were carried out to dilate the gastric cavity prior to CT examination.

　The accuracy of CT imaging for the existence and extent of the tumor was evaluated in comparison with macroscopic histopathology as the standard. In addition, the accuracy of tumor invasion depth（T stage）, and detectability of lymph node metastases were also discussed by referring to the pathological examination findings.

　The accuracy of tumor existence was 70％ on CT images without the expansion technique of gastric cavity. The scirrhous gastric cancers were detected as thicker gastric walls than non-tumorous area in 78％, and post contrast CT images revealed hyper-enhancement of the tumors in 54％ of enrolled cases. The sensitivity and specificity were revealed as 92％ and 75％ for the prediction of T2, respectively. The accuracy of detection of lymphnode metastasis was limited on the size-based criteria in the current study.