特発性腸間膜静脈硬化症の臨床―X線診断

Radiologic Diagnosis of Idiopathic Mesenteric Phlebosclerosis

要旨　特発性腸間膜静脈硬化症のX線画像所見の中で最も特徴的なものは，主として右側結腸領域に腸管の走行に一致して分布する多数の点状，網目状，線状の石灰化である．この所見は腹部単純X線写真，腹部CT写真，注腸X線写真などで捉えることができるが，石灰化が著明でなく内視鏡的粘膜変化のみが先行する場合もある．石灰化は，腸間膜付着側でより著明に認められ線状のものは腸管の短軸方向に走る．注腸X線所見では病変部腸管の拇指圧痕像，浮腫性粘膜，バリウム斑を伴う粘膜粗ぞう，haustraの形成不良・消失，辺縁鋸歯状不整，偽憩室様変形，壁硬化，伸展不良，管腔の狭小化などを認める．腹部CT所見では病変部腸管のびまん性壁肥厚，腸管壁内，壁周囲（腸間膜付着側），腸間膜内に点状，線状の石灰化を認める．造影CT静脈相の三次元画像解析は静脈壁石灰化の程度，血管罹患範囲の把握などに有用である．血管造影では腸間膜動脈分枝，辺縁動脈，直動脈の狭小化・蛇行，細枝の減少，直動脈や辺縁動脈に沿う静脈の拡張・蛇行，造影不良などを認める．

　The most characteristic finding among abdominal X-ray findings in idiopathic mesenteric phlebosclerosis is spotty, threadlike and linear calcification mainly at the right hemicolon. This finding is detected by conventional abdominal radiography, abdominal CT and barium enema radiography, but calcification is not remarkable and in some cases only a mucosal changes in the endoscopy may be apparent. The calcification is found more remarkably in the mesenteric side of the colon, and runs along an intestinal minor axis direction.

　Other findings of barium enema radiography in idiopathic mesenteric phlebosclerosis are thumbprinting, loss of haustra coli, irregularities and rigidity of bowel wall line, luminal narrowing and barium deposits due to ulcers. Abdominal CT findings in the disease are diffuse thickening of the intestinal wall and the calcification along the intestinal wall and in the mesenterium. Three-dimensional image analysis of the CT angiography is useful to detect the degree of the calcification of the vessel's wall and the range affected by it. The mesenteric angiography shows the narrowing and meandering of the mesenteric branch arteries, the marginal artery and the vasa recta, and shows expansion, meandering and decreased branching of veins along the marginal artery and the vasa recta.