森 雅美¹, 中尾 由佳¹, 井西 千晶¹, 錦 昌吾¹, 山田 沙由理¹, 福田 勝彦²

Masami MORI¹, Yuka NAKAO¹, Chiaki INISHI¹, Shogo NISHIKI¹, Sayuri YAMADA¹, Katsuhiko FUKUDA²

¹医療法人宝生会PL病院中央臨床検査部, ²医療法人宝生会PL病院内科

¹Department of Clinical Laboratory, PL General Hospital, ²Department of Internal Medicine, PL General Hospital

キーワード : splenic elasticity, chronic liver disease, real-time tissue elastography

目的：Real-time tissue elastography（RTE）を用いて慢性肝疾患における脾硬度測定を行い臨床的意義を検討した．対象および方法：対象は慢性肝疾患78例で 脾RTE画像から脾硬度を算出しspleen index（SI），PLT，APRI，肝硬度との関連を検討した．そのうち40例で超音波を用いた門脈圧亢進所見との関連を検討した．さらに食道静脈瘤（EV）の有無を確認できた73例で脾硬度をEV＋群，－群の2群間で比較検討し，EV＋34例で発赤所見（RC）等のEV内視鏡所見と比較検討した．結果と考察：SI，PLT，APRI，肝硬度と脾硬度の間には良好な相関関係を認め，脾硬度と門脈圧亢進所見の間にも良好な相関関係を認めた．EV＋群と－群の間では＋群の方が有意に脾硬度が上昇し（p＜0.0001），特にRC＋群は－群よりもさらに上昇した（p＜0.05）．EVおよびRC＋診断能をROC曲線を用いて検討したところ，脾硬度はEV（AUROC：0.93，cut off値72.2で感度84.6％，特異度91.2％），RC＋（AUROC：0.81，cut off値42.7で感度78.6％，特異度81.0％）で共に肝硬度よりも高かった．以上より脾硬度は門脈圧およびEVの有無と密接に関連することが示唆された．結論：RTEは慢性肝疾患における脾硬度評価に有用であり，EVの有無や出血を予測できるものと思われた．

Purpose: The purpose of this study is to clarify the clinical usefulness of splenic elasticity measured with real-time tissue elastography (RTE) in chronic liver disease. Subjects and Methods: Subjects were 78 patients with various chronic liver disease. We measured splenic and liver elasticity with RTE and compared those to the size of the spleen (spleen index: SI), platelet count (PLT), AST to platelet ratio index (APRI), and the degree of portal hypertension measured by US, respectively. We also studied the relationship between splenic elasticity and the presence and degree of esophageal varices (EV) in 73 patients who had undergone upper gastrointestinal endoscopy, and then evaluated the potential of splenic elasticity for predicting EV and EV with red color sign (RC+). Results and Discussion: Splenic elasticity was well correlated with SI, PLT, APRI, liver elasticity, and the degree of portal hypertension. Splenic elasticity values were significantly increased in the EV+ group, especially in the EV/RC+ group. Splenic elasticity was superior to liver elasticity for predicting both EV (AUROC: 0.93, cutoff value of 72.2 with 84.6% sensitivity and 91.2% specificity) and EV/RC+ (AUROC: 0.81, cutoff value of 42.7 with 78.6% sensitivity and 81.0% specificity). Conclusion: Splenic elasticity measured with RTE is a good predictor of the degree of portal hypertension in chronic liver disease and could be a promising tool that allows us to predict the presence and degree of EV.