Reducing Contrast-Agent Volume And Radiation Dose In CT With 90­Kvp Tube Voltage, High Tube Current Modulation, And Advanced Iteration Algorithm

The purpose of this study was to evaluate the image quality and the radiation dose in pancreatic dynamic CT with 90­kVp tube voltage and reduction of the standard amount of contrast agent, compared with 100­kVp PDCT. 51 patients who underwent both CT protocols were included in this retrospective study. One reviewer measured the attenuation values of the abdominal organs and image noise for objective image quality analysis. Two radiologists evaluated the five categories of image qualities for subjective image quality analysis. As a result, the total amount of the contrast agent, the radiation dose, and image noise decreased in the low-kVp group, by 24.4%, 31.7%, and 20.6%, respectively ( p  < 0.001). The intraobserver and interobserver agreements were moderate to substantial ( k  = 0.4 − 0.8). The SNR and CNR of the almost organs in the low-kVp group were significantly higher ( p  < 0.001). Except for lesion conspicuity, both reviewers judged that the subjective image quality of the low-kVp group was better ( p  < 0.001). With 90­kVp tube voltage, reduced contrast agent volume with advanced iteration and high tube current modulation achieved radiation dose reduction of 31.7%, as well as better image quality and diagnostic confidence.