二重造影像による動的観察からみたⅡc型病変の深達度診断

Radiodiagnostie Estimation of the Depth of Invasion in Type Ⅱc Cancer: From the view of dynamic observations by double contrast study

　肉眼的所見での深達度診断の指標^{6)11)13)14)17)18)25)27)}はいくつか指摘されている．そういう所見は，二重造影像か圧迫像でX線写真にあらわせばよい．しかし，指標がない病変もある．粘膜ひだ集中（瘢痕）をもつⅡc型のうち，病変の一部でsmに浸潤している例がそのひとつである．粘膜面の凹凸では深達度診断ができないものは，胃壁硬化を手がかりにしなければならない病変ということになる．

　胃壁硬化のX線所見には，充盈像と二重造影像における辺縁の伸展不良，硬化，硬直と表現される所見がある．ところが，胃中央部病変については，二重造影像は粘膜面の凹凸の様相を忠実にあらわすことができるが，軽度の胃壁硬化を診断する能力は少ない．また，圧迫像では，硬化部を，硬化の程度と圧迫の強さの程度との組み合わせの上で，造影剤がぬけた所見としてあらわすことができる．しかし，技術を要し，またそのX線所見上硬化の程度の数量化が難しい．圧迫像は経験的な要素が多分にあるというわけである．

　A study was made on variations of X-ray findings in the dynamic observation by the double contrast procedure. The findings in detail, the diagnostic significance and the diagnostic limitations are discussed.

　The results are described in individual headings, and the diagnoses for the depth of invasion are summarized as follows.

　1) A lesion in which X-ray findings were transient was suggestive of mucosal cancer (m cancer). Where mucosal folds were formed within Type Ⅱc lesion, the so-called thinning of the folds was recognized.

　2) A lesion in which X-ray findings were not transitory was considered two possibilities. When the lesion was smaller than 10 mm in the diameter, most cases showed m cancer. Focal submucosal invasion was present in only several cases (3/16).

　3) When a persisting lesion was over 10 mm in size, sm cancer was frequent. m cancer was seen in only 4 of 16 cases. The rigidity of the gastric wall in these cases of m cancer were caused by multiple ulcer scars, linear ulcer scar or marked submucosal fibrosis.

　Moreover, the extent or the grade of the rigidity of the gastric wall in the above mentioned persisting lesions can be easily judged by comparing individual X-ray findings on the decrease of the amount of air much, moderate and little.

　In addition, the border of Type Ⅱc lesion was more clearly recognizable in the stomach expanded by much or moderate volume of air. And the gastric areae around Type Ⅱc lesion were also easily seen. That is, the double contrast procedure by the greatest possible expansion of the stomach is indispensable for the determination of extent of cancer infiltration.

　In conclusion, dynamic observations by the double contrast procedure are most useful for the radiological diagnosis on the depth of invasion and the extent of an infiltration in Type Ⅱc cancer.