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

Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, One Deaconess Road, Boston, MA 02215, USA.
Radiology (Impact Factor: 6.87). 03/2009; 250(3):749-57. DOI: 10.1148/radiol.2503081078
Source: PubMed


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.
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.
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.
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.

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    • "Diagnosing appendicitis in pregnant patients is often complicated by atypical clinical presentations. The most common presenting symptom of appendicitis during pregnancy is right lower quadrant pain.3,4,8 Fever and leukocytosis are less reliable markers of acute pathology than in patients who are not pregnant.2,3,6 "
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    ABSTRACT: Abdominal pain frequently represents a diagnostic challenge in the acute setting. In pregnant patients, the gravid abdomen and concern for ionizing radiation exposure further limit evaluation. If undiagnosed, appendicitis may cause disastrous consequences for the mother and fetus. We present the case of a pregnant female who was admitted for right lower quadrant abdominal pain. Advanced imaging of the abdomen and pelvis was interpreted to be either indeterminate or normal and a diagnosis of acute appendicitis was made on purely clinical grounds. This patient's management and a literature review of diagnostic techniques for acute appendicitis during pregnancy are discussed.
    Full-text · Article · Sep 2014 · The western journal of emergency medicine
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    • "Magnetic resonance imaging (MRI) has been shown to be a useful method for the evaluation of pregnant women with suspected acute appendicitis and is increasingly used as an alternative for computed tomography (CT) in pediatric patients [1] [2] [3] [4], after negative or equivocal ultrasound results. In these populations MRI has been shown to be accurate, with advantages over CT in the absence of an increased risk of cancer induction due to ionizing radiation or of contrast induced nephropathy [5] [6]. "
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    ABSTRACT: Objective To compare accuracy and interobserver agreement between radiologists with limited experience in the evaluation of abdominal MRI (non-experts), and radiologists with longer MR reading experience (experts), in reading MRI in patients with suspected appendicitis. Methods MR imaging was performed in 223 adult patients with suspected appendicitis and read independently by two members of a team of eight MR-inexperienced radiologists, who were trained with 100 MR examinations previous to this study (non-expert reading). Expert reading was performed by two radiologists with a larger abdominal MR experience (>500 examinations) in consensus. A final diagnosis was assigned after three months based on all available information, except MRI findings. We estimated MRI sensitivity and specificity for appendicitis and for all urgent diagnoses separately. Interobserver agreement was evaluated using kappa statistics. Results Urgent diagnoses were assigned to 147 of 223 patients; 117 had appendicitis. Sensitivity for appendicitis was 0.89 by MR-non-expert radiologists and 0.97 in MR-expert reading (p = 0.01). Specificity was 0.83 for MR-non-experts versus 0.93 for MR-expert reading (p = 0.002). MR-experts and MR-non-experts agreed on appendicitis in 89% of cases (kappa 0.78). Accuracy in detecting urgent diagnoses was significantly lower in MR-non-experts compared to MR-expert reading: sensitivity 0.84 versus 0.95 (p < 0.001) and specificity 0.71 versus 0.82 (p = 0.03), respectively. Agreement on urgent diagnoses was 83% (kappa 0.63). Conclusion MR-non-experts have sufficient sensitivity in reading MRI in patients with suspected appendicitis, with good agreement with MR-expert reading, but accuracy of MR-expert reading was higher.
    Full-text · Article · Jan 2014 · European journal of radiology
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    • "There are no large studies conclusively demonstrating a superiority for MRI over other imaging modalities ( Rothrock & Pagane , 2000 ) . A recent study by Pedrosa et al ( 2009 ) studied 148 pregnant patients with suspected acute appendicitis . Their results showed that the use of magnetic resonance imaging did lower the incidence of negative laparotomies and perforation rates and thereby suggested a potential benefit . "

    Full-text · Chapter · Jan 2012
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