The Relationship Betueen Dosage And Images Quality In Ct Diagnosis Of Bowel Disease

Low dose of CT scanning with a good image quality is always a hot topic, and many scientists has been engaged in studying it. At the same time, with the quick development of CT technology, there are big changes of CT machines. Since the incidence of bowel disease has greatly increased with the changes of life level, and abdomen organs are very sensitive to get radiation injury, we try to reduce radiation dose which can meet the diagnostic quality when doing abdominal CT scan. So this study was performed to do low dose scanning of bowel in dual-source CT, in order to find the best parameters of scan and to protect patients with relative low radiation.It is well known that when radiation dose reaches 0.5-2.0Gy, it may cause anorexia, disgusting and vomit, and even diarrhea and heavy vomit when more than 5Gy. Studies showed that abdominal organs were very sensitive to radiation, and the rate for cancer might increase after big dose exposure.142 cases who did colon CT scan were involved in this study. Every body mass index was calculated before examination. We chose identical level to scan and reduced the electric current with fixed pitch, then selected the best current which could ensure image quality and meet the diagnostic need. Finally used the spssl3.0 statistics software to do the variance analysis.Results:All CT scans were performed using SIMENS Smaton Definition dual-source CT and analyzed by three radiologists. With the increasing of body mass index, the radiation dose had to increase to ensure the image quality. When exposure scope achieved 54.17%～79.17%, CT dosage index of single scanning could be possible to reach 54.17%～83.5%%. Lowest electric current may be controlled in the 65mAs-75mAs scope when body mass index was<19, in 75mA-85mA when body mass index was in 19 to 24, and in90mA-95mAs when>24.