An international evaluation of ultrasound vs. computed tomography in the diagnosis of appendicitis
Abdominal computed tomography scan (CT) is the preferred radiographic study for the diagnosis of appendicitis in the United States, while radiologist-operated ultrasound (US) is often used in Israel. This comparative international study evaluates the performance of CT vs. US in the evaluation of acute appendicitis.
A retrospective chart analysis was conducted at two tertiary care teaching hospitals, one in each country. Adult patients (age 18-99) with an Emergency Department (ED) working diagnosis of appendicitis between 1 January 2005 and 31 December 2006 were reviewed. Included patients had at least one imaging study, went to the OR, and had documented surgical pathology results.
Of 136 patients in the United States with the ED diagnosis of appendicitis, 79 met inclusion criteria for the CT cohort. Based on pathology, CT had a sensitivity of 100% (95% CI 95.4-100%). The negative appendectomy rate in patients with positive CT was 0%. Total median ED length of stay was 533 min [IQR (450-632)] and median time from CT order to completion was 184 min [IQR (147-228)]. Of 520 patients in Israel, 197 were included in the US cohort. Based on final pathology, US had a sensitivity of 68.4% (95% CI 61.2-74.8%). The negative appendectomy rate in patients with positive US was 5.5%. The median ED length of stay for these patients was 387 min [IQR (259-571.5)]. Of the patients, 23.4% had subsequent CT scans. Median time from US order to completion was 20 min [IQR (7-49)]. Both time values were p < 0.001 when compared with CT. We furthermore calculate that a "first pass" approach of using US first, and then performing a confirmatory CT scan in patients with negative US, would have saved an average of 88.0 minutes per patient in the United States and avoided CT in 65% of patients.
Radiologist-operated US had inferior sensitivity and positive predictive value when compared with CT, though was significantly faster to perform, and avoided radiation and contrast in a majority of patients. A "first-pass" approach using US first and then CT if US is not diagnostic may be desirable in some institutions.
- Addiss DG, Shaffer N, Fowler BS, Tauxe RV: The epidemiology of appendicitis and appendectomy in the United States. Am J Epidemiol 1990, 132:910–25.
- Sternbach G, Rosen P: Appendicitis: a continuing diagnostic challenge. J Emerg Med 1995, 13:95–6. CrossRef
- Laméris W, van Randen A, Go PM, Bouma WH, Donkervoort SC, Bossuyt PM, Stoker J, Boermeester MA: Single and combined diagnostic value of clinical features and laboratory tests in acute appendicitis. Acad Emerg Med 2009, 16:835–42. CrossRef
- Cardall T, Glasser J, Guss DA: Clinical value of the total white blood cell count and temperature in the evaluation of patients with suspected appendicitis. Acad Emerg Med 2004, 11:1021–7. CrossRef
- Wagner JM, McKinney WP, Carpenter JL: Does this patient have appendicitis? JAMA 1996, 276:1589–94. CrossRef
- Yeh B: Evidence-based emergency medicine/rational clinical examination abstract. Does this adult patient have appendicitis? Ann Emerg Med 2008, 52:301–3. CrossRef
- Terasawa T, Blackmore CC, Bent S, Kohlwes RJ: Systematic review: computed tomography and ultrasonography to detect acute appendicitis in adults and adolescents. Ann Intern Med 2004, 141:537–46.
- van Randen A, Bipat S, Zwinderman AH, Ubbink DT, Stoker J, Boermeester MA: Acute appendicitis: meta-analysis of diagnostic performance of CT and graded compression US related to prevalence of disease. Radiology 2008, 249:97–106. CrossRef
- Keyzer C, Zalcman M, De Maertelaer V, Coppens E, Bali MA, Gevenois PA, Van Gansbeke D: Comparison of US and unenhanced multi-detector row CT in patients suspected of having acute appendicitis. Radiology 2005, 236:527–34. CrossRef
- Weston AR, Jackson TJ, Blamey S: Diagnosis of appendicitis in adults by ultrasonography or computed tomography: a systematic review and meta-analysis. Int J Technol Assess Health Care 2005, 21:368–79. CrossRef
- Doria AS, Moineddin R, Kellenberger CJ, Epelman M, Beyene J, Schuh S, Babyn PS, Dick PT: US or CT for diagnosis of appendicitis in children and adults? A meta-analysis Radiology 2006, 241:83–94.
- Guss DA, Behling CA, Munassi D: Impact of abdominal helical computed tomography on the rate of negative appendicitis. J Emerg Med 2008, 34:7–11. CrossRef
- Gwynn LK: The diagnosis of acute appendicitis: clinical assessment versus computed tomography evaluation. J Emerg Med 2001, 21:119–23. CrossRef
- Brenner DJ, Hall EJ: Computed tomography- an increasing source of radiation exposure. N Engl J Med 2007, 357:2277–84. CrossRef
- Broder JS, Hollingsworth CL, Miller CM, Meyer JL, Paulson EK: Prospective double-blinded study of abdominal-pelvic computed tomography guided by the region of tenderness: estimation of detection of acute pathology and radiation exposure reduction. Ann Emerg Med 2010, in press.
- Broder J, Warshauer DM: Increasing utilization of computed tomography in the adult emergency department, 2000–2005. Emerg Radiol 2006, 13:25–30. CrossRef
- Howell JM, Eddy OL, Lukens TW, Thiessen MEW, Weingart SD, Decker WW: Clinical policy: critical issues in the evaluation and management of emergency department patients with suspected appendicitis. Ann Emerg Med 2010, 55:71–116. CrossRef
- Berg ER, Mehta SD, Mitchell P, Soto J, Oyama L, Ulrich A: Length of stay by route of contrast administration for diagnosis of appendicitis by computed-tomography scan. Acad Emerg Med 2006, 13:1040–5. CrossRef
- Gaitini D, Beck-Razi N, Mor-Yosef D, Fischer D, Ben Itzhak O, Krausz MM, Engel A: Diagnosing acute appendicitis in adults: accuracy of color Doppler sonography and MDCT compared with surgery and clinical follow-up. AJR Am J Roentgenol 2008, 190:1300–6. CrossRef
- Paulson EK, Kalady MF, Pappas TN: Clinical practice. Suspected appendicitis. N Engl J Med 2003, 348:236–42. CrossRef
- Morrow SE, Newman KD: Current management of appendicitis. Semin Pediatr Surg 2007, 16:34–40. CrossRef
- Berrington de González A, Mahesh M, Kim KP, Bhargavan M, Lewis R, Mettler F, Land C: Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med 2009, 169:2071–7. CrossRef
- Luxenburg O, Vaknin S, Pollack G, Siebzehner M, Shemer J: Utilization patterns of CT and MRI in Israel. Harefuah 2003, 142:810–4. 880
- Bree RL, Rosen MP, Foley WD: Expert Panel on Gastrointestinal Imaging. American College of Radiology Appropriateness Criteria. Right lower quadrant pain. [http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria.aspx]
- Poortman P, Oostvogel HJ, Bosma E, Lohle PN, Cuesta MA, de Lange-de Klerk ES, Hamming JF: Improving diagnosis of acute appendicitis: results of a diagnostic pathway with standard use of ultrasonography followed by selective use of CT. J Am Coll Surg 2009, 208:434–41. CrossRef
- Wan MJ, Krahn M, Ungar WJ, Caku E, Sung L, Medina LS, Doria AS: Acute appendicitis in young children: cost-effectiveness of US versus CT in diagnosis--a Markov decision analytic model. Radiology 2009, 250:378–86. CrossRef
- Ramarajan N, Krishnamoorthi R, Barth R, Ghanouni P, Mueller C, Dannenburg B, Wang NE: An interdisciplinary initiative to reduce radiation exposure: Evaluation of appendicitis in a pediatric emergency department with clinical assessment supported by a staged ultrasound and computed tomography pathway. Acad Emerg Med 2009, 16:1258–65. CrossRef
- Hlibczuk V, Dattaro JA, Jin Z, Falzon L, Brown MD: Diagnostic accuracy of noncontrast computed tomography for appendicitis in adults: a systematic review. Ann Emerg Med 2010, 55:51–59. CrossRef
- Min YG, Lee CC, Bae YS, Jung YS: Accuracy of sonography performed by emergency medicine residents for the diagnosis of acute appendicitis. Ann Emerg Med 2004, 44:S60. CrossRef
- Nelson MJ, Chiricolo GC, Raio CC, Theodoro DL, Patel T, Johnson AB: Can emergency physicians positively predict acute appendicitis on focused right lower quadrant ultrasound? Ann Emerg Med 2005, 46:S27–8. CrossRef
- Kameda T, Takahasi I: Pilot study to evaluate the accuracy of emergency physician-performed ultrasonography with a hand-held device in diagnosing acute appendicitis. Ann Emerg Med 2008, 51:543–4. CrossRef
- Summa M, Quarati R, Priora F, Spinoglio G, Malfitano A, Testa S, Perrone F, Aso SS, Antonio E, Biaggio EC: Acute appendicitis: ultrasonographic diagnosis. Acad Emerg Med 2004, 13:356–357. CrossRef
- An international evaluation of ultrasound vs. computed tomography in the diagnosis of appendicitis
- Open Access
- Available under Open Access This content is freely available online to anyone, anywhere at any time.
International Journal of Emergency Medicine
- Online Date
- October 2011
- Print ISSN
- Online ISSN
- Additional Links
- Author Affiliations
- 1. Tufts University School of Medicine, Boston, MA, USA
- 4. Department of Emergency Medicine, Beth Israel Deaconess Medical Center, West Campus, 330 Brookline Avenue, Boston, MA, 02215, USA
- 2. Department of Emergency Medicine, Shaare Zedek Medical Center, 12 Bayit Street, Jerusalem, 91031, Israel
- 3. Tufts Medical Center, Department of Emergency Medicine, Tufts University School of Medicine, Washington Street, Boston, MA, 02111, USA