Pregnant Patients Suspected of Having Acute Appendicitis: Effect of MR Imaging on Negative Laparotomy Rate and Appendiceal Perforation Rate

Published Online:Mar 1 2009https://doi.org/10.1148/radiol.2503081078

Abstract

Purpose: To investigate the effect of magnetic resonance (MR) imaging on the negative laparotomy rate (NLR) and the perforation rate (PR) in pregnant patients suspected of having acute appendicitis (AA) and to assess the need for computed tomography (CT) in this setting.

Materials and Methods: The data of 148 consecutive pregnant patients (mean age, 29 years; age range, 15–42 years; mean gestational age, 20 weeks; gestational age range, 4–37 weeks) who were clinically suspected of having AA and examined with MR imaging between March 2002 and August 2007 were retrospectively analyzed in an institutional review board–approved HIPAA-compliant protocol. One hundred forty patients underwent ultrasonography (US) before MR imaging. The clinical and laboratory data and the findings of the initial US and MR image interpretations were recorded and analyzed at Student t and Fisher exact testing. The NLR and PR were calculated.

Results: Fourteen (10%) patients had AA, and perforation occurred in three (21%) of them. US results were positive for AA in five (36%) patients with proved AA. MR results were positive in all 14 patients with AA. MR results were negative in 125 of the 134 patients without AA; there were nine false-positive cases (two positive, seven inconclusive). Among the patients without AA, the normal appendix could be visualized on US images in less than 2% (two of 126) of cases and on MR images in 87% (116 of 134) of cases (P < .0001). Twenty-seven (18%) patients underwent surgical exploration, and eight of them had negative laparotomy results, yielding an NLR of 30% and a PR of 21% (three of 14 patients). Only four (3%) patients underwent CT.

Conclusion: For pregnant patients clinically suspected of having AA, use of MR imaging yields favorable combinations of NLR and PR compared with previously reported values. The radiation exposure associated with CT examination can be avoided in most cases.

References

1 Mayer IE, Hussain H. Abdominal pain during pregnancy. Gastroenterol Clin North Am 1998; 27: 1–36. Crossref, Medline, Google Scholar
2 Hee P, Viktrup L. The diagnosis of appendicitis during pregnancy and maternal and fetal outcome after appendectomy. Int J Gynaecol Obstet 1999;65:129–135. Crossref, Medline, Google Scholar
3 Mourad J, Elliott JP, Erickson L, Lisboa L. Appendicitis in pregnancy: new information that contradicts long-held clinical beliefs. Am J Obstet Gynecol 2000;182:1027–1029. Crossref, Medline, Google Scholar
4 Bailey LE, Finley RK Jr, Miller SF, Jones LM. Acute appendicitis during pregnancy. Am Surg 1986;52:218–221. Medline, Google Scholar
5 Andersen B, Nielsen TF. Appendicitis in pregnancy: diagnosis, management and complications. Acta Obstet Gynecol Scand 1999;78:758–762. Crossref, Medline, Google Scholar
6 Velanovich V, Satava R. Balancing the normal appendectomy rate with the perforated appendicitis rate: implications for quality assurance. Am Surg 1992;58:264–269. Medline, Google Scholar
7 Berry J Jr, Malt RA. Appendicitis near its centenary. Ann Surg 1984;200:567–575. Crossref, Medline, Google Scholar
8 Balthazar EJ, Rofsky NM, Zucker R. Appendicitis: the impact of computed tomography imaging on negative appendectomy and perforation rates. Am J Gastroenterol 1998;93:768–771. Crossref, Medline, Google Scholar
9 Bendeck SE, Nino-Murcia M, Berry GJ, Jeffrey RB Jr. Imaging for suspected appendicitis: negative appendectomy and perforation rates. Radiology 2002;225:131–136. Link, Google Scholar
10 Togawa A, Kimura F, Chiku T, Sano W, Tashiro T, Miyazaki M. Simple way to improve accuracy in diagnosis of quadrant inflammatory disease: how to avoid adverse laparotomy by using plain CT. Hepatogastroenterology 2005;52:135–138. Medline, Google Scholar
11 Wallace CA, Petrov MS, Soybel DI, Ferzoco SJ, Ashley SW, Tavakkolizadeh A. Influence of imaging on the negative appendectomy rate in pregnancy. J Gastrointest Surg 2008;12:46–50. Crossref, Medline, Google Scholar
12 Tracey M, Fletcher HS. Appendicitis in pregnancy. Am Surg 2000;66:555–559. Medline, Google Scholar
13 Lim HK, Bae SH, Seo GS. Diagnosis of acute appendicitis in pregnant women: value of sonography. AJR Am J Roentgenol 1992;159:539–542. Crossref, Medline, Google Scholar
14 Birnbaum BA, Wilson SR. Appendicitis at the millennium. Radiology 2000;215:337–348. Link, Google Scholar
15 Jeffrey RB Jr, Laing FC, Townsend RR. Acute appendicitis: sonographic criteria based on 250 cases. Radiology 1988;167:327–329. Link, Google Scholar
16 Puylaert JB, Rutgers PH, Lalisang RI, et al. A prospective study of ultrasonography in the diagnosis of appendicitis. N Engl J Med 1987;317:666–669. Crossref, Medline, Google Scholar
17 Ralls PW, Balfe DM, Bree RL, et al. Evaluation of acute right lower quadrant pain: American College of Radiology—ACR appropriateness criteria. Radiology 2000;215(suppl):159–166. Medline, Google Scholar
18 Lazarus E, Mayo-Smith WW, Mainiero MB, Spencer PK. CT in the evaluation of nontraumatic abdominal pain in pregnant women. Radiology 2007;244:784–790. Link, Google Scholar
19 Cobben LP, Groot I, Haans L, Blickman JG, Puylaert J. MRI for clinically suspected appendicitis during pregnancy. AJR Am J Roentgenol 2004;183:671–675. Crossref, Medline, Google Scholar
20 Oto A, Ernst RD, Shah R, et al. Right-lower-quadrant pain and suspected appendicitis in pregnant women: evaluation with MR imaging—initial experience. Radiology 2005;234:445–451. Link, Google Scholar
21 Pedrosa I, Levine D, Eyvazzadeh AD, Siewert B, Ngo L, Rofsky NM. MR imaging evaluation of acute appendicitis in pregnancy. Radiology 2006;238:891–899. Link, Google Scholar
22 Puylaert JB. Acute appendicitis: US evaluation using graded compression. Radiology 1986;158:355–360. Link, Google Scholar
23 Pedrosa I, Zeikus EA, Levine D, Rofsky NM. MR imaging of acute right lower quadrant pain in pregnant and nonpregnant patients. RadioGraphics 2007;27:721–743. Link, Google Scholar
24 Gwynn LK. Appendiceal enlargement as a criterion for clinical diagnosis of acute appendicitis: is it reliable and valid? J Emerg Med 2002;23:9–14. Crossref, Medline, Google Scholar
25 Daly CP, Cohan RH, Francis IR, Caoili EM, Ellis JH, Nan B. Incidence of acute appendicitis in patients with equivocal CT findings. AJR Am J Roentgenol 2005;184:1813–1820. Crossref, Medline, Google Scholar
26 Ganguli S, Raptopoulos V, Komlos F, Siewert B, Kruskal JB. Right lower quadrant pain: value of the nonvisualized appendix in patients at multidetector CT. Radiology 2006;241:175–180. Link, Google Scholar
27 Nikolaidis P, Hwang CM, Miller FH, Papanicolaou N. The nonvisualized appendix: incidence of acute appendicitis when secondary inflammatory changes are absent. AJR Am J Roentgenol 2004;183:889–892. Crossref, Medline, Google Scholar
28 McGory ML, Zingmond DS, Tillou A, Hiatt JR, Ko CY, Cryer HM. Negative appendectomy in pregnant women is associated with a substantial risk of fetal loss. J Am Coll Surg 2007;205:534–540. Crossref, Medline, Google Scholar
29 Flum DR, Morris A, Koepsell T, Dellinger EP. Has misdiagnosis of appendicitis decreased over time? a population-based analysis. JAMA 2001;286:1748–1753. Google Scholar
30 in't Hof KH, van Lankeren W, Krestin GP, et al. Surgical validation of unenhanced helical computed tomography in acute appendicitis. Br J Surg 2004;91:1641–1645. Crossref, Medline, Google Scholar
31 Antevil J, Rivera L, Langenberg B, Brown CV. The influence of age and gender on the utility of computed tomography to diagnose acute appendicitis. Am Surg 2004;70:850–853. Medline, Google Scholar
32 Brenner DJ, Hall EJ. Computed tomography: an increasing source of radiation exposure. N Engl J Med 2007;357:2277–2284. Crossref, Medline, Google Scholar
33 Hurwitz LM, Yoshizumi T, Reiman RE, et al. Radiation dose to the fetus from body MDCT during early gestation. AJR Am J Roentgenol 2006;186:871–876. Crossref, Medline, Google Scholar
34 McCollough CH, Schueler BA, Atwell TD, et al. Radiation exposure and pregnancy: when should we be concerned? RadioGraphics 2007;27:909–917. Link, Google Scholar
35 ACOG Committee on Obstetric Practice. ACOG Committee opinion: number 299, September 2004 (replaces no. 158, September 1995)—guidelines for diagnostic imaging during pregnancy. Obstet Gynecol 2004;104:647–651. Crossref, Medline, Google Scholar
36 Barloon TJ, Brown BP, Abu-Yousef MM, Warnock N, Berbaum KS. Sonography of acute appendicitis in pregnancy. Abdom Imaging 1995;20:149–151. Crossref, Medline, Google Scholar
37 Kessler N, Cyteval C, Gallix B, et al. Appendicitis: evaluation of sensitivity, specificity, and predictive values of US, Doppler US, and laboratory findings. Radiology 2004;230:472–478. Link, Google Scholar
38 Johansson EP, Rydh A, Riklund KA. Ultrasound, computed tomography, and laboratory findings in the diagnosis of appendicitis. Acta Radiol 2007;48:267–273. Crossref, Medline, Google Scholar
39 Oto A, Srinivasan PN, Ernst RD, et al. Revisiting MRI for appendix location during pregnancy. AJR Am J Roentgenol 2006;186:883–887. Crossref, Medline, Google Scholar
40 Balthazar EJ, Megibow AJ, Siegel SE, Birnbaum BA. Appendicitis: prospective evaluation with high-resolution CT. Radiology 1991;180:21–24. Link, Google Scholar
41 Bickell NA, Aufses AH Jr, Rojas M, Bodian C. How time affects the risk of rupture in appendicitis. J Am Coll Surg 2006;202:401–406. Crossref, Medline, Google Scholar
42 Lee SL, Walsh AJ, Ho HS. Computed tomography and ultrasonography do not improve and may delay the diagnosis and treatment of acute appendicitis. Arch Surg 2001;136:556–562. Crossref, Medline, Google Scholar
43 Riesenman PJ, Riesenman KP, Stone TJ, Beidler SK, Douillet CD, Rich PB. Nonfocused enhanced CT evaluation of acute appendicitis increases length of stay in the emergency department but does not increase perforation rate. Am Surg 2008;74:488–492. Crossref, Medline, Google Scholar
44 Birchard KR, Brown MA, Hyslop WB, Firat Z, Semelka RC. MRI of acute abdominal and pelvic pain in pregnant patients. AJR Am J Roentgenol 2005;184:452–458. Crossref, Medline, Google Scholar
45 Oto A, Ernst RD, Ghulmiyyah LM, et al. MR imaging in the triage of pregnant patients with acute abdominal and pelvic pain. Abdom Imaging doi:10.1007/s00261-008-9381-y. Published online March 11, 2008. Accessed August 11, 2008. Google Scholar
46 Israel GM, Malguria N, McCarthy S, Copel J, Weinreb J. MRI vs ultrasound for suspected appendicitis during pregnancy. J Magn Reson Imaging 2008;28:428–433. Crossref, Medline, Google Scholar
47 Kanal E. Pregnancy and the safety of magnetic resonance imaging. Magn Reson Imaging Clin N Am 1994;2:309–317. Crossref, Medline, Google Scholar
48 De Wilde JP, Rivers AW, Price DL. A review of the current use of magnetic resonance imaging in pregnancy and safety implications for the fetus. Prog Biophys Mol Biol 2005;87:335–353. Crossref, Medline, Google Scholar
49 Levine D, Zuo C, Faro CB, Chen Q. Potential heating effect in the gravid uterus during MR HASTE imaging. J Magn Reson Imaging 2001;13:856–861. Crossref, Medline, Google Scholar

Article History

Published in print: 2009

Vol. 250, No. 3

Metrics

Altmetric Score

PDF download