Acute abdomen: CT or ultrasound?

Acute abdomen: CT orultrasound?Chiu-Mei Lin, MD, Ph.DDepartment of Emergency MedicineShin Kong Wu Ho-Su Memorial Hospital

Learning objective‣ Benefits of CT in the patient present withacute abdomen‣ When do you need the CT scan?‣ When do you need ultrasound?2011/11/02 Lin 2

Case: abdominal pain for 10 days‣ 58 y/o male patient present with RUQpain for 10 days, no fever‣ Blood WBC: 11200, Seg.: 86%‣ Past history: DM2011/11/02 Lin 3

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Choice of computed tomography(CT) versus ultrasound‣ Radiation dose‣ Operator's level of training‣ Patient's age and sex‣ Condition of patient’s cooperation‣ Obesity or not‣ Other situations2011/11/02 Lin 7

CT scan‣ High sensitivity‣ High specificity‣ Accuracy‣ Availability‣ Not real-time, but dynamic study by arteryvein-delayedphase‣ Lack of operator dependence2011/11/02 Lin 8

NEJM, 20072011/11/02 Lin 9

Ultrasound‣ Inexpensive‣ Portable‣ Safe‣ No requirement for radiation‣ Dynamic and real-time survey‣ Operator dependence: solid or holloworgan, experiences2011/11/02 Lin 10

CT for appendicitis‣ CT for appendicitis has a higher sensitivity(90%-100%) and specificity (95%-97%)Radiology 2000;215:337-48‣ CT use in suspected acute appendicitis hasgreatly increased over the past several years.The dramatic increase in CT use at ourinstitution has not resulted in dramaticdecreases in negative appendectomy rate orstatistically significant changes in perforationrate. Am Surg. 2001 ;67(11):1017-21.2011/11/02 Lin 11

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1. Swelling blinded-end loop2. Swelling of cecum3. Perifocal inflammation2011/11/02 Lin 14

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Choice CT or ultrasound‣ Diagnosis‣ Surveillance‣ Monitoring disease response to therapy‣ Exacerbation or dynamic survey:ultrasound2011/11/02 Lin 16

Abdominal CTAbdominal CT can reveal:‣ Appendicitis‣ Gallstones or biliary sludge in the gallbladder or bileducts‣ Kidney stones‣ Enlarged lymph nodes anywhere in the abdominal cavity‣ Thickened intestinal wall, like in lymphoma‣ Diverticulosis‣ Abdominal tumors‣ Enlarged liver, spleen or kidneys‣ Location and spread of abdominal cancers2011/11/02 Lin 17

However, DDx is concerned (CT)‣ Mis- or delayed diagnosed?‣ Unknown diagnosis?‣ Young female patient, GI or GYN problem?‣ Intractable abdominal pain (infarction orvascular lesion?)‣ High risk patient (sometimes…VIP)‣ With or without contrast medium?2011/11/02 Lin 18

Case: abdominal pain for 1 day‣ 62 y/o male patient present with upperabdominal pain for 1 day, no fever‣ Blood WBC: 9600, Seg.: 86%‣ Past history: lymphoma2011/11/02 Lin 19

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Choice of ultrasound‣ Solid organ lesion‣ Hollow organ lesion (training andeducation)– operator dependence‣ Trauma patient survey and follow-up‣ Ascites localization2011/11/02 Lin 23

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Take home message‣ Emergency CT scan for acute abdomen:peritonitis, suspect bowel obstruction,vascular lesion (SMA occlusion etc)‣ Ultrasound: FAST, solid organs, holloworgan (need training and education)2011/11/02 Lin 25