Shifeng Tian, Presenter: Nothing to Disclose

Ailian Liu MD, Abstract Co-Author: Nothing to Disclose

Jinghong Liu, Abstract Co-Author: Nothing to Disclose

Chen Anliang, Abstract Co-Author: Nothing to Disclose

Yijun Liu, Abstract Co-Author: Nothing to Disclose

Renwang Pu MBBCh, FRCPC, Abstract Co-Author: Nothing to Disclose

To investigate the low concentration contrast medium combined with optimal monochromatic parameters of CT angiography (CTA)on small tumor blood supply arteries of gastrointestinal tract malignant tumors using single source dual-energy CT spectral imaging(GSI)technique.

This study was approved by the ethics committee of our hospital. 71 patients with gastrointestinal tract malignant tumors were analyzed prospectively . All the cases were randomly divided into two groups termed A and B. Group A contained 33 cases using high concentration of contrast medium in routine scan, lines of conventional 120 kVp polychromatic energy full abdominal scan and tri-phase dynamic enhanced scan, concentration of 350 mg I/ml contrast medium was injected; group B contained 38 cases using low concentration of contrast medium in optimal monochromatic parameters scan group, followed by routine tri-phase total abdominal scan using spectral CT imaging injected concentration of 270 mg I/ml contrast medium. The images of two groups were reconstructed and evaluated by two radiologists using 5-scale score. The inter observer agreement was evaluated by Kappa and subjective rating were compared by Mann - Whitney U . CT HU value, image noise , contrast- to- noise ratio (CNR) and CT dose index(CTD Ivol）were compared by independent sample t test.

The inter observer agreement for subjective scores is very good (Kappa value > 0.80); ICC (ICC value > 0.75). Subjective image quality scores, CT HU values, image noise, CNR and CTDIvol of high concentration group and low concentration group were 2.64±0.86 points and 3.53±0.69 points, 242.80±41.44HU and 408.41±50.72HU, 21.03±2.66HU and 18.67±2.18HU, 8.95±2.51 and 18.60±2.17. The differences were statistically significant (P < 0.05) . The CTDIvol of two groups were 17.84±4.68mGy and 16.87±0.00mGy respectively , the differences was no statistically significant (P =0.205) .

The low concentration contrast medium optimal monochromatic mode can improve CTA quality of small tumor blood supply arteries of gastrointestinal tract malignant tumors with GSI technique using single source dual-energy CT，and the radiation dose not increase．

The low concentration contrast medium optimal monochromatic mode can reduce the concentration of contrast medium, reduce the incidence of contrast medium side effects.

Tian, S, Liu, A, Liu, J, Anliang, C, Liu, Y, Pu, R, A Preliminary Study of CT Angiography on Small Tumor Blood Supply Arteries of Gastrointestinal Tract Malignant Tumors with Low Concentration Contrast Medium Optimizing Gemstone Spectral Imaging Technique Using Single Source Dual-energy CT.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003815.html