Akut Apandisit Bulgularının Dual Enerji Bt İle Değerlendirilmesi
Özet
Despite the gradual increase of utilization dual-energy computed tomography (DECT) in the field of abdominal radiology, solid studies of acute appendicitis (AA) regarding this imaging technique have yet to be done. We hereby aimed to assess the utility of DECT in the diagnosis of AA. The DECT scans of consecutive 30 patients (14 male, 16 female) with AA and 30 consecutive patients (14 male, 16 female) with normal appendix vermiformis (AV) were recruited to this study. The maximum diameter of AV as well as the density of most compressed and inflamed site of AV at 80 kVp, 140 kVp, virtual non-contrast (VNC), iodine overlay, mixed, and monoenergetic (40,50,60,70,80,90,100,190 keV) images were quantified. The maximum diameter was 11.5±2.3 mm in AA patients and 5.7±0.5 mm in control group (p<0.001). The attenuation values of inflamed AVs were higher than that of normal AVs at 80 kVp, 140 kVp, VNC, iodine overlay, mixed images and all virtual monochromatic energy levels (p<0.001). The attenuation values of inflamed AVs at 80 kVp, 140 kVp, VNC, iodine overlay, mixed images were 101.5±20.1 HU, 59.5±13.7 HU, 20.7±11.7 HU, 50.6±9.7 HU, 71.9±15.9 HU respectively. The attenuation values of normal AVs at 80 kVp, 140 kVp, VNC, iodine overlay, mixed images were 52.6±12.3 HU, 31.1±13.4 HU, 1.4±16.6 HU, 37.4±13.4 HU, 38.3±11.7 HU respectively. The attenuation values of inflamed AVs at virtual monochromatic images generated from 40 to 100 keV energy levels in 10-keV increments were 204.3±40.2 HU, 136.1±27.4 HU, 103.4±19.2 HU, 79.1±15.5 HU, 64.6±31.6 HU, 55.1±12.6 HU, 48.9±12.9 HU respectively. The attenuation values of normal AVs at virtual monochromatic images generated from 40 to 100 keV energy levels in 10-keV increments were 146±49.7 HU, 97.9±30.3 HU, 69.4±20.4 HU, 46.7±10.8 HU, 38.6±10.2 HU, 31.8±12 HU, 26.3±12.5 HU respectively. The sensitivity and specificity values were calculated for certain cut-off attenuation values as ranging from 73.3% to 96.7% for each. 80 kVp images yielded the highest diagnostic accuracy with AUC of 0.996 following maximum diameter with AUC of 1 (p<0.001). 70 keV and 80 keV energy levels out of the virtual monochoromatic images provided the highest diagnostic accuracies with AUC of 0.958 and 0.934, respectively. In conclusion, AA can be more easily detected in iodine overlay, low kVp and low energy monochromatic images of DECT due to increased attenuation values at certain energy levels. The 80 kVp and virtual energy monochromatic images at 70 keV and 80 keV energy levels yield the highest diagnostic accuracies in the setting of AA.