Yeni gelişen apandiksin iltiahbinda vücuttaki suyun hereketine duyarli manyetik rezonans görüntüleme tekniğinin katkisi

Purpose The aim of this study is to investigate the diagnostic role of diffusion-weighted Magnetic Resonance imaging (DW-MRI) in cases with acute appendicitis when used solitarily and to evaluate the effectiveness of DW-MRI and quantitative measurement of ADC values. Materials and Methods Our retrospective study includes 35 cases with a diagnosis of acute appendicitis with clinical and imaging findings (all have ultrasonography and some have both US and computed tomography) as the patients group and 20 cases with no acute abdominal symptoms as the control group. Pelvic MRI examinations of the study and control groups were performed 1.5 Tesla (T) body MRI (GE Signa HDxt) using (TR: 4000 msn, TE:76,5msn; FOV, 440cm, matrix, 320×256; slice gap 1mm; slice thickness, 7 mm; b:0,800 mm²/sn). As it was not possible to define precise appendix localization on DW-MRI for the control group because of, for low spatial resolution, the ADC measurements were obtained from cecum wall which had similar histology with appendix. Presence of tubular structure starting from the base of cecum to tip blind ending on the right lower quadrant as appendix have been researched in the patient groups with DWI b0 sequence and was recorded signal intensities of this view on the b800 sequence. ADC values were measured from this area by circular ROI without exceeding the limits of wall of the cecum on ADC maps. Results One of thirty-five patients had no sign of acute appendicitis on US and histological examination. Twentyfive patients who had clinical and imaging findings of appendicitis were operated the histopathological diagnosis was appendicitis all of them. Another 9 patients were followed up without operation and diagnosed as resolving appendicitis due to resolution of the ultrasonographic and clinical findings. In our study, the sensitivity of US and CT was 84 % and 100% respectively in the diagnosis of acute appendicitis. The inflammed appendix was hyperintense in 97%, and iso- hyperintense 3% of the cases on DW MRI. The ADC values of the inflammed appendix were measured betwen 0,8x10-3 mm2/sn to 2,2 x10-3 mm2/sn in cases with appendicitis whereas the mean ADC value was 1,28x10-3 mm2/sn. Normal apendix was not seen as hyperintense in the control group on Diffusion-weighted imaging. The ADC values of normal cecum wall were measured between 1,4x10-3 mm2/sn to 2,4 x10-3 mm2/sn on DW-ADC maps. The mean ADC value is 1,84 x10-3 mm2/sn in these control group. On receiver operator characteristics (ROC) curve analysis based on ADC of study and control groups, the cut-off value for the diagnosis of appendicitis was 1.45×10-3 mm2/sn with a sensitivity of 90 % and specificity of 68% , 1.45×10-3 mm2/sn with a sensitivity of 81 % and specificity of 76%. Conclusion It has been thought with relevant literature that awarness of typical DWI findings of acute appendicitis may help to prevent complications resulted from mis or delayed diagnosis and to determine therapeutic approach when combined with other routinely used imaging modalities or in cases who had contraindications to them.