Bestoun Ahmed1, Jon Williams2, William Gourash3, Jun Zhang4, Runjia Li5, Goundappa K Balasubramani6, Balasubramanya Rangaswamy7. 1. Department of Surgery, Division of Minimally Invasive General and Bariatric Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA. Electronic address: ahmedbh2@upmc.edu. 2. Advanced Laparoscopic and General Surgery of Nevada, Las Vegas, NV. 3. Department of Surgery, Division of Minimally Invasive General and Bariatric Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA. 4. Astellas Pharma, Beijing, China. 5. Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, PA. 6. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, PA. 7. Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA.
Abstract
OBJECTIVE: Evaluation of acute appendicitis (AA) in pregnancy is supported with diagnostic imaging. Typically, ultrasound (US) is performed first, and then often followed by magnetic resonance imaging (MRI) due to continued diagnostic uncertainty. The purpose of our study was to evaluate the sensitivity, specificity, and accuracy of US as compared to MRI and to evaluate the inter-radiologist agreement amongst body Radiologists with varying levels of expertise. MATERIALS AND METHODS: We performed a retrospective study of 364 consecutive pregnant patients with clinical suspicion of AA at a single center over a 6-year period. Sensitivity, Specificity, accuracy, positive and negative predictive values were calculated for US and MRI. Inter Radiologist agreement was determined using Cohen's Kappa analysis between original interpreting Radiologist and retrospective review by expert Radiologist. RESULTS: Thirty-one of 364 patients (8.5%) underwent appendectomy based on preoperative diagnosis, with confirmation of acute appendicitis (AA) by pathology in 19. US was able to visualize the appendix in only 6 (1.65%), 5 of whom had appendicitis. 141 patients underwent MRI, and correctly diagnosed appendicitis in 9. No patient with a negative MRI diagnosis had AA. The sensitivity, and negative predictive value for diagnosing AA with MRI was 100%. The MRI inter-reader agreement for appendix visualization and overall accuracy were 87.9 and 98% with Cohen Kappa of 0.7 and 0.56 respectively. CONCLUSIONS: Our data suggests that MRI should be considered the first line imaging modality in pregnant patients suspected of having AA. Body Radiologists with varied levels of experience in MRI readouts had substantial agreement.
OBJECTIVE: Evaluation of acute appendicitis (AA) in pregnancy is supported with diagnostic imaging. Typically, ultrasound (US) is performed first, and then often followed by magnetic resonance imaging (MRI) due to continued diagnostic uncertainty. The purpose of our study was to evaluate the sensitivity, specificity, and accuracy of US as compared to MRI and to evaluate the inter-radiologist agreement amongst body Radiologists with varying levels of expertise. MATERIALS AND METHODS: We performed a retrospective study of 364 consecutive pregnant patients with clinical suspicion of AA at a single center over a 6-year period. Sensitivity, Specificity, accuracy, positive and negative predictive values were calculated for US and MRI. Inter Radiologist agreement was determined using Cohen's Kappa analysis between original interpreting Radiologist and retrospective review by expert Radiologist. RESULTS: Thirty-one of 364 patients (8.5%) underwent appendectomy based on preoperative diagnosis, with confirmation of acute appendicitis (AA) by pathology in 19. US was able to visualize the appendix in only 6 (1.65%), 5 of whom had appendicitis. 141 patients underwent MRI, and correctly diagnosed appendicitis in 9. No patient with a negative MRI diagnosis had AA. The sensitivity, and negative predictive value for diagnosing AA with MRI was 100%. The MRI inter-reader agreement for appendix visualization and overall accuracy were 87.9 and 98% with Cohen Kappa of 0.7 and 0.56 respectively. CONCLUSIONS: Our data suggests that MRI should be considered the first line imaging modality in pregnant patients suspected of having AA. Body Radiologists with varied levels of experience in MRI readouts had substantial agreement.
Authors: Ivan Pedrosa; Michelle Lafornara; Pari V Pandharipande; Jeffrey D Goldsmith; Neil M Rofsky Journal: Radiology Date: 2009-03 Impact factor: 11.105