Dual-energy CT (DECT) that includes virtual monoenergetic imaging or iodine overlay imaging can improve the assessment of acute appendicitis, according to research published in the American Journal of Roentgenology and presented at RSNA 2017 in Chicago.
“The accuracy of CT in differentiating gangrenous appendicitis without perforation from uncomplicated appendicitis is not well established,” wrote lead author Khaled Y. Elbanna, MBBCh, Vancouver General Hospital in Vancouver, British Columbia, Canada, and colleagues. “We hypothesized that implementation of DECT and spectral imaging techniques can improve the diagnostic accuracy of acute gangrenous appendicitis.”
The authors studied data from more than 200 patients diagnosed with appendicitis. Two abdominal radiologists reviewed simulated images. A total of 44 patients had gangrenous appendicitis. Virtual monoenergetic imaging had a sensitivity of 100 percent, specificity of more than 81 percent, positive predictive value (PPV) of more than 58 percent and negative predictive value (NPV) of 100 percent. Iodine overlay imaging had a sensitivity of 100 percent, specificity of 80 percent, PPV of more than 57 percent and NPV of 100 percent.
On the other hand, 120-kv simulated imaging had a sensitivity of more than 22 percent, specificity of more than 96 percent, PPV of 62.5 percent and NPV of more than 82 percent.
“Virtual monoenergetic and iodine overlay imaging reconstructions can be used for accurate diagnosis of gangrenous appendicitis without perforation with a high degree of sensitivity and specificity,” the authors wrote. “Therefore, virtual monoenergetic imaging and iodine overlay imaging datasets add clinical value to DECT of the abdomen and pelvis for assessment of acute appendicitis.”