Murat Karul MD, Presenter: Nothing to Disclose

Cyrus Behzadi, Abstract Co-Author: Nothing to Disclose

Maxim Avanesov MD, Abstract Co-Author: Nothing to Disclose

Thorsten Derlin, Abstract Co-Author: Nothing to Disclose

Gerhard B. Adam MD, Abstract Co-Author: Nothing to Disclose

Jin Yamamura MD, Abstract Co-Author: Nothing to Disclose

To compare findings on computed tomography (CT) with both histopathology and C-reactive protein (CRP) in patients with acute appendicitis (AA).

76 consecutive patients (age 56±17.9y; range 23-97y) were categorized into one of three groups (GR) based on the histopathologic evaluation: ulcero-phlegmonous AA (GR1), gangrenous AA (GR2), and perforation (GR3). All patients underwent preoperative contrast-enhanced low-dose CT. Two blinded readers reviewed images in consensus and patients were assigned into one of three GR using following criteria: Patients in GR1/GR2 showed wall thickness (2-3mm/>3mm) with ring-like contrast enhancement, a cross-sectional diameter (6-10mm/>10mm), and moderate/high grade of periappendiceal fat attenuation, respectively, and patients in GR3 showed an abscess formation in the RLQ. CRP levels were correlated using p-values from Mann-Whitney’s U test and receiver operating characteristic (ROC) curve analysis was performed for identification of cutoff-point for perforation.

According to histopathological evaluation, 49/76 patients (64.5%) were assigned into GR1, 5/76 patients (6.6%) into GR2, and 22/76 patients (28.9%) into GR3. Using MDCT, 42/49 patients (85.7%) were correctly identified as GR1, however, 7/49 patients (14.3%) were falsely classified as GR2. 2/5 patients (40%) were correctly identified as GR2, and 3/5 patients (60%) were falsely classified as GR1. 19/22 patients (86.4%) were correctly identified as GR3, and 3/22 patients (13.6%) were falsely classified as GR2. Mean CRP was 56mg/l ± 99 (range 0-359mg/l) in GR1, 117mg/l ± 64 (range 32-208mg/l) in GR2, and 139mg/l ± 84 (range 59-353mg/l) in GR3. CRP was significantly different between GR1 and GR3 (p<0.03). ROC analysis revealed an optimal cut-off point of >72mg/l for identification of perforation (AUC=0.725), resulting in a sensitivity of 86.4% and a specificity of 55.1%. CRP was neither significantly different between GR1 and GR2 (p=0.206) nor between GR2 and GR3 (p=0.786).  

In patients with suspected AA and highly elevated CRP levels, CT is able to rule out perforation.

CT may help to predict the relevant differences in histopathological grading. The differentiation between patients in GR1 and GR3 could lead to a different surgical approach (open vs. laparascopic).

Karul, M, Behzadi, C, Avanesov, M, Derlin, T, Adam, G, Yamamura, J, Adults with Acute Appendicitis: Comparison between Computed Tomography, Histopathological Findings and C-reactive Protein.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045601.html