Low-Dose Hepatopancreatic MDCT: Practical Experience of Applicability

Abstract

Aims: to evaluate the possibilities of low-dose MDCT protocols in visualization of liver and pancreatic tumors.Materials and methods. 40 patients were enrolled in study and divided into 2 groups. Two scanning protocols were used, differing by the voltage on the X-ray tube-standard 120 kV, and the modified 100 kV. All studies were performed with intravenous administration of a contrast agent. The data – noise, a circumference of abdominal cavity, a relation “contrast-noise”, data of contrast strengthening of organs were evaluated. The tomograms were reconstructed using standard and iterative reconstruction algorithms. A qualitative assessment of the images was carried out according to 2 parameters – the evaluation of the whole image and the visualization of tumor on a 3-point scale.Results. Radiation exposure decreased by 31.5% using the modified protocol. The noise level did not differ with the use of standard reconstruction, but it decreased markedly using iterative reconstruction. The contrast-to-noise ratio turned out to be higher in the “100 kV” group and consistently increased with increasing levels of iterative reconstruction. Evaluations of the visualization of tumors were significantly higher in the “100 kV” group.Conclusion. The use of low-dose protocols is justified, it allows to seriously reduce the radiation exposure, improving visualization of the liver and pancreas tumors (primarily hypervascular). Application of iterative reconstruction algorithms allows achieving significant improvement in image quality and noise reduction.