Application Of Low-kVp CT Scanning Technique Combined With Low Concentration Contrast Medium In Diagnosis Colorectal Cancer

Objective: To explore the value of low-concentration contrast combined with low k VP CT scanning technology in the diagnosis of colorectal cancer.Methods:(1)Double low colon CT imaging study: 58 patients with clinical colon CT enhanced examination were grouped according to body mass index(BMI).In the double low group,26 patients had a BMI <25.After intestinal cleansing,gas injection,scanning parameters: 80 kVp,automatic For m A and contrast agent,Viscount Parker was used at270 mg / 100ml;in the conventional group,32 patients had scanning parameters: 120 kVp,automatic m A,and contrast agent at Onepac or Uni Vision 300 mg / 100 ml.Subjective scoring and objective evaluation of the image quality of the two groups of patients were performed,and statistical comparison analysis of the radiation dose,CNR,and SNR of the two groups of patients.(2)Contrast analysis of CT diagnosis and pathological results of surgery or colorectoscopy in the double low group.Results:(1)The radiation dose volume CT dose index(CTDIvol)of the double low group and the conventional group were(5.6 ± 1.1)m Gy and 13.3(9.6,16.7)m Gy,P <0.01,and the CTDI of the double low group was significantly lower than that of the conventional group.The difference between the two groups was statistically significant.The CNR and SNR of abdominal aorta,portal vein,superior mesenteric artery,inferior mesenteric artery,liver,and colon in the 70% double low group and the conventional group images are equivalent,and the difference between the two groups is not statistically significant;The evaluation results show that the image quality of the two groups is equal,and the difference is not statistically significant.The evaluation of the two groups of images by the two doctors was highly consistent(P <0.01).(2)The diagnostic rate of colorectal cancer using double low CT colonography is 88.5%,the sensitivity is 90.9%,the specificity is 75%,the positive predictive value is 95.2%,and the negative predictive value is 60%.Conclusion: The radiation dose of colon CT enhanced scanning with low kVp combined with low concentration contrast agent is significantly lower than that of the conventional 120 kVp group,and the image quality is equivalent.Double low CT colon imaging is a safer,comprehensive,and noninvasive method for colorectal cancer.