總膽管結石之緊急超音波診斷─影響結石檢出率因素之研究

Urgent Ultrasonography in Diagnosis of Choledocholithiasis--Analysis on Factors Influencing Stone Detection

目的：本研究在分析緊急超音波檢查對總膽管結石的檢出率，以及影響檢出率的因素。材料與方法：總共92個經由內視鏡膽胰攝影術證實的總膽管結石病人，他們在來院時就安排緊急超音波檢查。我們把檢查結果分為3組；第一組：超音波發現總膽管擴張及總膽管結石，第二組：超音波發現總膽管擴張但無法看到結石，第三組：超音波發現總膽管無擴張且無法看到結石。本研究就各組之間的總膽管大小、結石大小、與結石數目作比較分析。結果：緊急超音波檢查對總膽管結石的檢出率為57.6% （53/92）。第一組病人的平均總膽管直徑為16.8±6.1公釐，第二組為13.6±3.5公釐，第三組為6.5±1.0公釐（p<0.005）。總膽管結石的大小第一組為23.1±12.2公釐，第二組為13.0±5.3公釐，第三組為9.0±4.5公釐。（p<0.0005）此外，若總膽管結石大於或等於20公釐，則結石檢出率為86.4% （32/37）；若結石大小界於10到19公釐之間，結石檢出率為44.1% （15/34）；若結石小於10公釐，則結石檢出率為19.0% （4/21）。（p<0.0005）結論：緊急超音波檢查可以檢出57.6%的總膽管結石。影響總膽管結石檢出之因素包括總膽管徑的大小，以及總膽管結石的大小。

PURPOSE: We obser ved the sensitivity of ultrasonography to detect choledocholithiasis under emergency basis and evaluated factors influencing the ultrasonic stone detection rate other than inadequate patient preparation. MATERIAL AND METHOD: 92 patients receiving urgent ultrasound examination and subsequently proved choledocholithiasis by endoscopic retrograde cholangiography were classified into 3 groups; Group I: with ultrasound findings of ductal dilatation and intraductal stone, Group II: ductal dilatation without visible stone by ultrasound, and Group III: neither ductal dilatation nor intraductal stone visible. Common duct dimension and stone size were measured and compared in these 3 groups of patients as well. RESULT: The overall ultrasonic intraductal stone detection rate was 57.6% (53/92). The mean common duct dimension in Group I was 16.8±6.1mm, in Group II was 13.6±3.5mm, and in Group III was 6.5±1.0mm (F test, p<0.005). The mean ductal stone dimension was 23.1±12.2mm in Group I, 13.0±5.3mm in Group II and 9.0±4.5mm in Group III respectively (F test, p<0.0005). The stone detection rate was 86.4% (32/37) in patients with common duct stone size of ≥20mm in diameter, 44.1%(15/34) in stone size between 10 to 19mm, and 19.0%(4/21) in stone size of<10mm in diameter. CONCLUSION: The urgent ultrasound had an overall sensitivity of 57.6%in detecting choledocholithiasis. Factors influencing ultrasonic detection rate of common duct stone other than inadequate patient preparation include common ductsize and intraductal stone size.