Skip to main content
Top
Published in: European Radiology 2/2016

01-02-2016 | Computed Tomography

CT following US for possible appendicitis: anatomic coverage

Authors: Martin E. O’Malley, Fawaz Alharbi, Tanya P. Chawla, Hadas Moshonov

Published in: European Radiology | Issue 2/2016

Login to get access

Abstract

Objective

To determine superior-inferior anatomic borders for CT following inconclusive/nondiagnostic US for possible appendicitis.

Methods

Ninety-nine patients with possible appendicitis and inconclusive/nondiagnostic US followed by CT were included in this retrospective study. Two radiologists reviewed CT images and determined superior-inferior anatomic borders required to diagnose or exclude appendicitis and diagnose alternative causes. This “targeted” coverage was used to estimate potential reduction in anatomic coverage compared to standard abdominal/pelvic CT.

Results

The study group included 83 women and 16 men; mean age 32 (median, 29; range 18-73) years. Final diagnoses were: nonspecific abdominal pain 50/99 (51 %), appendicitis 26/99 (26 %), gynaecological 12/99 (12 %), gastrointestinal 9/99 (10 %), and musculoskeletal 2/99 (2 %). Median dose-length product for standard CT was 890.0 (range, 306.3 – 2493.9) mGy.cm. To confidently diagnose/exclude appendicitis or identify alternative diagnoses, maximum superior-inferior anatomic CT coverage was the superior border of L2-superior border of pubic symphysis, for both reviewers. Targeted CT would reduce anatomic coverage by 30-55 % (mean 39 %, median 40 %) compared to standard CT.

Conclusions

When CT is performed for appendicitis following inconclusive/nondiagnostic US, targeted CT from the superior border of L2-superior border of pubic symphysis can be used resulting in significant reduction in exposure to ionizing radiation compared to standard CT.

Key Points

• When CT is used following inconclusive/ nondiagnostic ultrasound, anatomic coverage can be reduced.
• CT from L2 to pubic symphysis can be used to diagnose/exclude appendicitis.
• Reduced anatomic coverage for CT results in reduced exposure to ionizing radiation.
Literature
1.
go back to reference Pena BM, Taylor GA, Fishman SJ, Mandl KD (2000) Costs and effectiveness of ultrasonography and limited computed tomography for diagnosing appendicitis in children. Pediatrics 106:672–676PubMedCrossRef Pena BM, Taylor GA, Fishman SJ, Mandl KD (2000) Costs and effectiveness of ultrasonography and limited computed tomography for diagnosing appendicitis in children. Pediatrics 106:672–676PubMedCrossRef
2.
go back to reference Coursey CA, Nelson RC, Patel MB et al (2010) Making the diagnosis of acute appendicitis: do more preoperative CT scans mean fewer negative appendectomies? a 10-year study. Radiology 254:460–468PubMedCrossRef Coursey CA, Nelson RC, Patel MB et al (2010) Making the diagnosis of acute appendicitis: do more preoperative CT scans mean fewer negative appendectomies? a 10-year study. Radiology 254:460–468PubMedCrossRef
3.
go back to reference Rao PM, Rhea JT, Novelline RA, Mostafavi AA, McCabe CJ (1998) Effect of computed tomography of the appendix on treatment of patients and use of hospital resources. N Engl J Med 338:141–146PubMedCrossRef Rao PM, Rhea JT, Novelline RA, Mostafavi AA, McCabe CJ (1998) Effect of computed tomography of the appendix on treatment of patients and use of hospital resources. N Engl J Med 338:141–146PubMedCrossRef
4.
go back to reference Rao PM, Rhea JT, Novelline RA, McCabe CJ, Lawrason JN, Berger DL et al (1997) Helical CT technique for the diagnosis of appendicitis: prospective evaluation of a focused appendix CT examination. Radiology 202:139–144PubMedCrossRef Rao PM, Rhea JT, Novelline RA, McCabe CJ, Lawrason JN, Berger DL et al (1997) Helical CT technique for the diagnosis of appendicitis: prospective evaluation of a focused appendix CT examination. Radiology 202:139–144PubMedCrossRef
5.
go back to reference Christopher FL, Lane MJ, Ward JA, Morgan JA (2002) Unenhanced helical CT scanning of the abdomen and pelvis changes disposition of patients presenting to the emergency department with possible acute appendicitis. J Emerg Med 23:1–7PubMedCrossRef Christopher FL, Lane MJ, Ward JA, Morgan JA (2002) Unenhanced helical CT scanning of the abdomen and pelvis changes disposition of patients presenting to the emergency department with possible acute appendicitis. J Emerg Med 23:1–7PubMedCrossRef
6.
go back to reference Wilson EB, Cole JC, Nipper ML, Cooney DR, Smith RW (2001) Computed tomography and ultrasonography in the diagnosis of appendicitis: when are they indicated? Arch Surg 136:670–5PubMedCrossRef Wilson EB, Cole JC, Nipper ML, Cooney DR, Smith RW (2001) Computed tomography and ultrasonography in the diagnosis of appendicitis: when are they indicated? Arch Surg 136:670–5PubMedCrossRef
7.
go back to reference Doria AS, Moineddin R, Kellenberger CJ, Epelman M, Beyene J, Schuh S et al (2006) US or CT for diagnosis of appendicitis in children and adults? A Meta-Analysis. Radiology 241:83–94PubMedCrossRef Doria AS, Moineddin R, Kellenberger CJ, Epelman M, Beyene J, Schuh S et al (2006) US or CT for diagnosis of appendicitis in children and adults? A Meta-Analysis. Radiology 241:83–94PubMedCrossRef
9.
go back to reference van Randen A, Bipat S, Zwinderman AH, Ubbink DT, Stoker J, Boermeester MA (2008) Acute appendicitis: meta-analysis of diagnostic performance of CT and graded compression US related to prevalence of disease. Radiology 249:97–106PubMedCrossRef van Randen A, Bipat S, Zwinderman AH, Ubbink DT, Stoker J, Boermeester MA (2008) Acute appendicitis: meta-analysis of diagnostic performance of CT and graded compression US related to prevalence of disease. Radiology 249:97–106PubMedCrossRef
10.
go back to reference (2006) National Research Council Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation. Health risks from exposure to low levels of ionizing radiation: BEIR VII, Phase 2. Washington, DC: National Academies Press (2006) National Research Council Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation. Health risks from exposure to low levels of ionizing radiation: BEIR VII, Phase 2. Washington, DC: National Academies Press
11.
go back to reference Pickhardt PJ, Lubner MG, Kim DH, Tang J, Ruma JA, del Rio AM et al (2012) Abdominal CT with model-based iterative reconstruction (MBIR): initial results of a prospective trial comparing ultralow-dose with standard-dose imaging. AJR 199:1266–74PubMedPubMedCentralCrossRef Pickhardt PJ, Lubner MG, Kim DH, Tang J, Ruma JA, del Rio AM et al (2012) Abdominal CT with model-based iterative reconstruction (MBIR): initial results of a prospective trial comparing ultralow-dose with standard-dose imaging. AJR 199:1266–74PubMedPubMedCentralCrossRef
12.
go back to reference Sagara Y, Hara AK, Pavlicek W, Silva AC, Paden RG, Wu Q (2010) Abdominal CT: comparison of low-dose CT with adaptive statistical iterative reconstruction and routine-dose CT with filtered back projection in 53 patients. AJR 195:713–719PubMedCrossRef Sagara Y, Hara AK, Pavlicek W, Silva AC, Paden RG, Wu Q (2010) Abdominal CT: comparison of low-dose CT with adaptive statistical iterative reconstruction and routine-dose CT with filtered back projection in 53 patients. AJR 195:713–719PubMedCrossRef
13.
go back to reference Funama Y, Awai K, Nakayama Y, Kakei K, Nagasue N, Shimamura M et al (2005) Radiation dose reduction without degradation of low-contrast detectability at abdominal multisection CT with a low-tube voltage technique: phantom study. Radiology 237:905–910PubMedCrossRef Funama Y, Awai K, Nakayama Y, Kakei K, Nagasue N, Shimamura M et al (2005) Radiation dose reduction without degradation of low-contrast detectability at abdominal multisection CT with a low-tube voltage technique: phantom study. Radiology 237:905–910PubMedCrossRef
14.
go back to reference Kim K, Kim YH, Kim SY, Kim S, Lee YJ, Kim KP et al (2012) Low-dose abdominal CT for evaluating suspected appendicitis. N Engl J Med 366:1596–605PubMedCrossRef Kim K, Kim YH, Kim SY, Kim S, Lee YJ, Kim KP et al (2012) Low-dose abdominal CT for evaluating suspected appendicitis. N Engl J Med 366:1596–605PubMedCrossRef
15.
go back to reference Poortman P, Oostvogel HJ, Bosma E, Lohle PN, Cuesta MA, de Lange-de Klerk ES et al (2009) 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 208:434–441PubMedCrossRef Poortman P, Oostvogel HJ, Bosma E, Lohle PN, Cuesta MA, de Lange-de Klerk ES et al (2009) 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 208:434–441PubMedCrossRef
16.
go back to reference Krishnamoorthi R, Ramarajan N, Wang NE, Newman B, Rubesova E, Mueller CM et al (2011) Effectiveness of a staged US and CT protocol for the diagnosis of pediatric appendicitis: reducing radiation exposure in the age of ALARA. Radiology 259:231–9PubMedCrossRef Krishnamoorthi R, Ramarajan N, Wang NE, Newman B, Rubesova E, Mueller CM et al (2011) Effectiveness of a staged US and CT protocol for the diagnosis of pediatric appendicitis: reducing radiation exposure in the age of ALARA. Radiology 259:231–9PubMedCrossRef
17.
go back to reference Toorenvliet BR, Wiersma F, Bakker RF, Merkus JW, Breslau PJ, Hamming JF (2010) Routine ultrasound and limited computed tomography for the diagnosis of acute appendicitis. World J Surg 34:2278–85PubMedPubMedCentralCrossRef Toorenvliet BR, Wiersma F, Bakker RF, Merkus JW, Breslau PJ, Hamming JF (2010) Routine ultrasound and limited computed tomography for the diagnosis of acute appendicitis. World J Surg 34:2278–85PubMedPubMedCentralCrossRef
18.
go back to reference Parker L, Nazarian LN, Gingold EL, Palit CD, Hoey CL, Frangos AJ (2014) Cost and radiation savings of partial substitution of ultrasound for CT in appendicitis evaluation: a national projection. AJR 202:124–135PubMedCrossRef Parker L, Nazarian LN, Gingold EL, Palit CD, Hoey CL, Frangos AJ (2014) Cost and radiation savings of partial substitution of ultrasound for CT in appendicitis evaluation: a national projection. AJR 202:124–135PubMedCrossRef
19.
go back to reference Jacobs JE, Birnbaum BA, Macari M, Megibow AJ, Israel G, Maki DD et al (2001) Acute appendicitis: comparison of helical CT diagnosis focused technique with oral contrast material versus nonfocused technique with oral and intravenous contrast material. Radiology 220:683–690PubMedCrossRef Jacobs JE, Birnbaum BA, Macari M, Megibow AJ, Israel G, Maki DD et al (2001) Acute appendicitis: comparison of helical CT diagnosis focused technique with oral contrast material versus nonfocused technique with oral and intravenous contrast material. Radiology 220:683–690PubMedCrossRef
20.
go back to reference Brassart N, Winant C, Tack D, Gevenois PA, De Maertelaer V, Keyzer C (2013) Optimised z-axis coverage at multidetector-row CT in adults suspected of acute appendicitis. Br J Radiol 86:20130115PubMedPubMedCentralCrossRef Brassart N, Winant C, Tack D, Gevenois PA, De Maertelaer V, Keyzer C (2013) Optimised z-axis coverage at multidetector-row CT in adults suspected of acute appendicitis. Br J Radiol 86:20130115PubMedPubMedCentralCrossRef
21.
go back to reference Rao PM, Feltmate CM, Rhea JT, Schulick AH, Novelline RA (1999) Helical computed tomography in differentiating appendicitis and acute gynecologic conditions. Obstet Gynecol 93:417–421PubMedCrossRef Rao PM, Feltmate CM, Rhea JT, Schulick AH, Novelline RA (1999) Helical computed tomography in differentiating appendicitis and acute gynecologic conditions. Obstet Gynecol 93:417–421PubMedCrossRef
22.
go back to reference Kamel IR, Goldberg SN, Keogan MT, Rosen MP, Raptopoulos V (2000) Right lower quadrant pain and suspected appendicitis: nonfocused appendiceal CT - review of 100 cases. Radiology 217:159–163PubMedCrossRef Kamel IR, Goldberg SN, Keogan MT, Rosen MP, Raptopoulos V (2000) Right lower quadrant pain and suspected appendicitis: nonfocused appendiceal CT - review of 100 cases. Radiology 217:159–163PubMedCrossRef
23.
go back to reference Paulson EK, Harris JP, Jaffe TA, Haugan PA, Nelson RC (2005) Acute appendicitis: added diagnostic value of coronal reformations from isotropic voxels at multi-detector row CT. Radiology 235:879–885PubMedCrossRef Paulson EK, Harris JP, Jaffe TA, Haugan PA, Nelson RC (2005) Acute appendicitis: added diagnostic value of coronal reformations from isotropic voxels at multi-detector row CT. Radiology 235:879–885PubMedCrossRef
Metadata
Title
CT following US for possible appendicitis: anatomic coverage
Authors
Martin E. O’Malley
Fawaz Alharbi
Tanya P. Chawla
Hadas Moshonov
Publication date
01-02-2016
Publisher
Springer Berlin Heidelberg
Published in
European Radiology / Issue 2/2016
Print ISSN: 0938-7994
Electronic ISSN: 1432-1084
DOI
https://doi.org/10.1007/s00330-015-3778-0

Other articles of this Issue 2/2016

European Radiology 2/2016 Go to the issue