Prospective evaluation of MRI compared with CT for the etiology of abdominal pain in emergency department patients with concern for appendicitis

Abstract

Background Computed tomography (CT) is commonly used in the Emergency Department (ED) to evaluate patients with abdominal pain, but exposes them to ionizing radiation, a possible carcinogen. MRI does not utilize ionizing radiation and may be an alternative. Purpose To compare the sensitivity of MRI and CT for acute abdominopelvic ED diagnoses. Study Type Prospective, observational cohort. Population ED patients ≥12 years old and undergoing CT for possible appendicitis. Field Strength/Sequence 1.5 T MRI, including T1‐weighted, T2‐weighted, and diffusion‐weighted imaging sequences. Assessment Three radiologists independently interpreted each MRI and CT image set separately and blindly, using a standard case report form. Assessments included likelihood of appendicitis, presence of an alternative diagnosis, and likelihood that the alternative diagnosis was causing the patient's symptoms. An expert panel utilized chart review and follow‐up phone interviews to determine all final diagnoses. Times to complete image acquisition and image interpretation were also calculated. Statistical Tests Sensitivity was calculated for each radiologist and by consensus (≥2 radiologists in agreement) and are reported as point estimates with 95% confidence intervals. Two‐sided hypothesis tests comparing the sensitivities of the three image types were conducted using Pearson's chi‐squared test with the traditional significance level of P = 0.05. Results There were 15 different acute diagnoses identified on the CT/MR images of 113 patients. Using individual radiologist interpretations, the sensitivities of noncontrast‐enhanced MRI (NCE‐MR), contrast‐enhanced MR (CE‐MR), and CT for any acute diagnosis were 77.0% (72.6–81.4%), 84.2% (80.4–88.0%), and 88.7% (85.5–92.1%). Sensitivity of consensus reads was 82.0% (74.9–88.9%), 87.1% (81.0–93.2%), 92.2% (87.3–97.1%), respectively. There was no difference in sensitivities between CE‐MR and CT by individual (P = 0.096) or consensus interpretations (P = 0.281), although NCE‐MR was inferior to CT in both modes of analysis (P < 0.001, P = 0.031, respectively). Data Conclusion The sensitivity of CE‐MR was similar to CT when diagnosing acute, nontraumatic abdominopelvic pathology in our cohort. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1651–1658.

Rapid MRI Abdomen for Assessment of Clinically Suspected Acute Appendicitis in the General Adult Population: a Systematic Review

“…Eight primary cohort studies were identified that compared MRI and the reference standard with respect to their ability to identify alternative diagnoses when appendicitis was clinically suspected. 31 , 34 , 39 , 42 , 43 , 46 , 62 , 63 The sensitivity and specificity of MRI for alternative diagnoses ranged between 77.0–100% 34 , 62 and 94.9–100%, 34 , 43 respectively. Seven of these studies additionally reported the data with a restriction to gynaecological pathologies, with the values of sensitivity and specificity ranging between 57.1–100% 34 , 63 and 95.3–100%, 34 , 43 respectively.…”

“… 67 The variable results on the sensitivity of MRI may be partially attributable to the varying levels of MRI experience of the interpreting radiologists in different studies, 34 , 63 as the sensitivity of MRI interpretation can improve with training. 62 …”

Preoperative prediction of complicated appendicitis using machine learning method

“…As popularized imaging tools for acute appendicitis, the sensitivity and speci city were reported to be over 90% for CT and over 80% for ultrasound [9,10]. The sensitivity of noncontrast-enhanced MRI can also approach 77% [11]. With technological innovations, researchers or clinicians start to pay more attention in timely and accurately identifying pathological types of appendicitis before treatment.…”