The Patient Radiation Dose in Whole Abdomen and Thorax Computed Tomography at Songklanagarind Hospital

Abstract

The purpose of this study is to determine the patient radiation dose and the factors affecting in order to develop the potential methods for the radiation dose reduction. The basic population consists of 100 patients who underwent the chest and abdominal computed tomography examinations at Songklanagarind Hospital. The result shows the average dose length product. DLP, calculated for chest and abdominal CT of 448.10 and 1,192.59 mGy.cm respectively. The average weighted CT Dose Index CTDiw were 8.4 mGy for chest and 11.2 mGy for abdomen. 47 patients or 94 percent for DLP chest CT were lower than the dose reference level of 650 mGy.cm. For abdominal CT, 44 patients or 88 percent of sample population received the radiation dose higher than the dose reference level of 800 mGy.cm. All CTDiw were below the dose reference level of 30 mGy for chest and 35 mGy for routine abdomen.

The major factors affecting the patient radiation dose are the scan techniques such as the tube voltage, tube current, the scan time. the slice thickness. the scan length and the number of the phases or scans. Adaptation of the scan techniques, the reconstruction algorithm and the adjustment of the slice thickness to the appropriate scan length enable the reduction of the patient dose. The result of this study will lead to the awareness of the radiologists and technologists for the proper use of CT especially whole abdomen in young adult and in pediatric studies.