Virtual unenhanced images derived from spectral CT imaging accessing gastric carcinoma: a feasible study

To qualitatively and quantitatively compare MSI images and WB images derived from spectral CT imaging with CU images in accessing gastric carcinoma. The clinical data and imaging findings of 91 cases of gastric carcinomas between December 2013 and May 2015 were analyzed retrospectively. All patients underwent CU CT and enhanced CT with spectral imaging in AP and VP. MSI images were reconstructed based on monochromatic images of 70 keV in AP. WB images were obtained by water-iodine pair substance isolation of the AP images. Two abdominal radiologists independently evaluated the image quality and the depiction of gastric carcinoma in CU, MSI and WB images using a 5-point scale. The sensitivities of gastric cancer were evaluated by using enhanced images as the reference standard.The CT number of various regions, image noise, relative enhancement CT value of tumors and metastasis were measured and calculated on CU and MSI images. The CNR of gastric tumor were measured on CU, MSI and WB images. Effective radiation