Clinical utility of magnetic resonance imaging in the evaluation of pregnant females with suspected acute appendicitis.

OBJECTIVES: To assess the diagnostic performance of magnetic resonance imaging (MRI) in a large cohort of pregnant females with suspected acute appendicitis and to determine the frequency of non-appendiceal causes of abdominal pain identified by MRI in this population. METHODS: This HIPAA compliant, retrospective study was IRB-approved and informed consent was waived. 212 MRI exams were performed consecutively on pregnant women aged 17-47 years old suspected of having acute appendicitis; eight exams were excluded and analyzed separately due to equivocal findings or lack of clinical follow up. Radiology reports for the MRI and any preceding ultrasound exams were reviewed as well as the patients' electronic medical record for surgical, pathological, or clinical follow up. RESULTS: Fifteen (7.3%) of 204 MRI scans were determined to be positive for appendicitis, 14 of which were proven on surgical pathology, and one was found to have ileocecal diverticulitis. Out of the remaining 189 scans, none were subsequently shown to have acute appendicitis either surgically or based on clinical follow up. Negative predictive value (NPV) was 100% and positive predictive value was 93.3%. Sensitivity and specificity were 100% and 99.5%, respectively. Non-appendiceal findings which may have accounted for the patient's abdominal pain were seen in 91 (44.2%) of 189 scans. The most common extra-appendiceal causes of abdominal pain identified on MRI include degenerating fibroids (n = 11), significant hydronephrosis (n = 12), cholelithiasis (n = 6), and pyelonephritis (n = 3). CONCLUSION: Our large study cohort of pregnant patients confirms MRI to be of high diagnostic value in the workup of acute appendicitis with 100% NPV and sensitivity and 99.5% specificity. Furthermore, an alternative diagnosis for abdominal pain in this patient population can be made in nearly half of MRI exams which are deemed negative for appendicitis.

Incidence of intravenous contrast extravasation: increased risk for patients with deep brachial catheter placement from the emergency department.

Deep brachial intravenous catheter (IV) placement can be performed in emergency department patients with difficult vascular access, but the safety of deep brachial IV for iodinated contrast administration has not been assessed. This study compares the relative risk for extravasation of deep brachial IV compared with antecubital IV during power injected computed tomography (CT) examinations. A departmental practice quality improvement was performed to assess the rate of IV extravasation for all CT examinations during a 1 year period. De-identified data was analyzed with a waiver of informed consent to identify the rate and relative risk of iodinated contrast extravasation by catheter type. A total of 10,750 injections were performed, with 82 extravasation events (0.8 %). There were 51 extravasations of antecubital IV from approximately 8,599 placed (0.6 %). For 123 deep brachial IV placed, there were eight extravasations (6.5 %). The relative risk of a deep brachial IV extravasation was 9.4 compared to 0.4 for antecubital placement. Deep brachial IV demonstrated a markedly higher rate of contrast extravasation than antecubital IV. For power injected iodinated contrast administration, it is recommended to avoid the use of deep brachial IV whenever possible.