Virtual Non-contrast CT with Spectral CT as an Alternative to Unenhanced CT in Assessment of Gastric Cancer

Gastric cancer accounts for approximately 8% of new cancers worldwide (Jemal et al., 2011). Early diagnosis and accurate preoperative staging are critical for improving outcomes, and this includes the identification of the tumor location, depth of invasion, lymph node status, and the presence of metastasis (Monig et al., 2002; Chen et al., 2007; Makino et al., 2011). Current methods for the detection of gastric cancer include upper gastrointestinal endoscopy and barium studies, computed tomography (CT), and magnetic resonance imaging (MRI) (Liu and Chen, 2012). CT imaging is an important means for staging gastric cancer, and contrast-enhanced CT can assess the depth of tumor invasion and lymph node and distant organ metastasis, which may guide gastric cancer staging before surgery and aid postoperative follow-up (Monig et al., 2002; Chen et al., 2007; Makino et al., 2011; Liu and Chen, 2012). CT imaging spectroscopy can obtain a water/iodine density map through paired substance isolation (Johnson