Protective role of organ dose modulation technology in the radiation sensitive organs during the CT angiography of craniocervical arteries

Abstract

Objective To investigate the effectiveness of organ dose modulation (ODM) technology with respect to dose reduction and image quality of the sensitive organs during CTA of craniocervical arteries. Methods Ninety one patients suspected of arterial vascular disease and evaluated by CTA of craniocervical arterires were enrolled in this study. Patients were divided into group A (n=46) and group B (n=45) according to the order of examination. All patients hadCTA examination of craniocervical arteries. The ODM technique was used only in plain phase in group A and was used both in the plain phase and enhanced phase in group B. The tube current in the four direction (anterior,posterior,left,right) of thyroid and orbital area and radiation dose were recorded. The image quality of group A and group B was evaluated by objective indicators [CT attenuation values and contrast-to-noise ratio (CNR) of vessels in the thyroid area and orbital region] and the subjective score. The independent samples t test was used for the statistical analysis of the objective indicators and nonparametric rank sum Mann-Whitney U test were used for subjective score. Results For A group, There were significant differences for the tube current at all directions of the thyroid gland and orbital area between the plain phase and the enhanced phase except the current at the posterior of the thyroid gland area(P value all 0.05). Conclusion ODM technique can provide protective effect on the sensitive organs during craniocervical CTA examination without compromising the image quality. Key words: Tomography,X-ray computed; Radiation dosage; Angiography