Serhat Avcu MD, Presenter: Nothing to Disclose

Feray Altun Cetin, Abstract Co-Author: Nothing to Disclose

Halil Arslan MD, Abstract Co-Author: Nothing to Disclose

Ozgur Kemik, Abstract Co-Author: Nothing to Disclose

Ahmet Cumhur Dulger, Abstract Co-Author: Nothing to Disclose

The aim of this study was to evaluate the effectiveness of diffusion-weighted magnetic resonance imaging (DWI) and quantitative measurement of apparent diffusion coefficient (ADC) values in the diagnosis of acute appendicitis cases, with histopathologic correlation.

Sixty consecutive patients (34 M, 26 F, range: 13-87 years) with a presumptive diagnosis of acute appendicitis were included in this prospective study. Twenty subjects with no abdominal complaint constituted the control group. Abdominal MRI examinations were performed with a 1.5 Tesla unit (Siemens Symphony). Before DWI, axial and coronal T2-weighted True-FISP and TIRM sequences were obtained. DWI examinations were maintained with single shot TSE echoplanar sequence and b values of 50, 400 and 800 mm²/sec. ADC calculations were made from the ADC maps by placing ROI (region of interest: 9-22 mm2) on the inflamed appendix wall in case group and on the normal cecal mucosa in control group (ROI: 3-6 mm2). Using SPSS programme, independent samples t-test was used to compare the mean ADC values of case and control groups, as well as perforated and non-perforated cases.  

Of the 60 cases, 44 had a radiologic diagnosis of acute appendicitis, and 16 were regarded as normal. Fifteen of these 16 patients were followed up clinically and their symptoms resolved.  Five of the 44 patients did not accept surgical operation and were excluded from the study. Of the 40 patients who underwent surgical operation, 12 had a histopathological diagnosis of perforated appendicitis and 28 of them non-perforated appendicitis. Mean ADC values in patients with acute appendicitis were significantly lower than control group, being 1.01±0.26x10-3 mm2/sec and 1.85±0.13x10-3 mm2/sec, respectively (p<0.001). Mean ADC values in the perforated group were found to be significantly lower than non-perforated group, being 0.79±0.19x10-3 mm2/sec and 1.11±0.22x10-3 mm2/sec, respectively (p<0.001). The sensitivity, specificity, PPV, NPV, and accuracy rate of DWI in the diagnosis of acute appendicitis were found to be 97.5%, 100%, 97.5%, 100%, and 98.1%, respectively.  

DWI and ADC quantification seem to be very effective in the diagnosis of acute appendicitis, both in perforated and non-perforated cases.

DWI seems to be very effective in the diagnosis of acute appendicitis, and we suggest it should be used in routine practice.  

Avcu, S, Cetin, F, Arslan, H, Kemik, O, Dulger, A, The Value of Diffusion-weighted Imaging and Apparent Diffusion Coefficient Quantification in the Diagnosis of Acute Appendicitis.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9008258.html