ヘリカルCTによる三次元表示が病変の把握に有用であったⅡa型早期胃癌の1例

Type Ⅱa Early Gastric Cancer Imaged by Three-Dimensional Helical CT, Report of a Case

要旨　患者は74歳，女性．心窩部不快感があり，近医での内視鏡検査で胃体上部小彎後壁寄りに不整形の隆起性病変を指摘され当科に紹介された．胃X線二重造影第2斜位像では丈の低い辺縁不整なはじき像として描出されたが，正面像では脊椎と重なるため詳細な観察が困難であった．胃内視鏡でⅡa集簇と診断，生検組織では高分化型腺癌であった．本例にヘリカルCTを用いて胃の三次元表示を試みた．この三次元表示は観察角度を自由に設定できるため，脊椎や周辺のガスが除かれ病変部の把握に有用であった．更に三次元上の腫瘍径も測定可能であった．本症例のような比較的凹凸の少ない病変では，axial画像で病変が把握できなくても三次元表示を試みることにより，病変の詳細を確認することが可能であると考えられた．

　A 74-year-old female suffered from gastric cancer and was admitted to our hospital. Radiological examination revealed that the gastric cancer appeared as an irregular elevated lesion at the posterior wall of the upper gastric corpus. However, it was difficult to measure the diameter on the film because the tumor was overlaid by spines. Endoscopic examination disclosed some aggregated flat and granular lesions at the posterior wall of the upper gastric corpus. The histological finding was well differentiated adenocarcinoma. In this case, in an attempt to evaluate the size more exactly, we tried to image the carcinoma using three-dimensional helical CT (3D-CT). It made it much easier to understand the details of the carcinoma and avoided the superimposition of spines and colon gas because 3D-CT was able to give on image from various angles. Moreover, the diameter of the carcinoma was able to be exactly measured by 3D-CT. It is our conclusion that 3D-CT will be a one of the new modalities for gastric cancer examinations.