The evaluation of chronic aortic diseases, many protocols of low radiation dose and low medium iodined contrast dose are performed. The main aim of this study is to give a preliminary evaluation of dose reduction and iodined dose reduction. In our Hospital from February 2013 to November 2016 we selected 150 patients divided into two groups: 60 for our study and group of control of 90 cases. All CT examinations were performed with a 64-MDCT scan. (Optima-CT GE Healtcare) Tube voltage was reduced in our study (80 kVp versus 120 in our standard) with automated current modulation system in both groups. Concerning the iodined dose reduction, in the study groups it is strongly reduced (40 cc of 370 mg/ml versus 90 cc of 370 mg/ml): a mechanical power injector was used to administer contrast material via catheters (20-gauge) placed in antecubital vein at a flow rate of 4.5 ml/sec Two radiologists qualitaively graded image quality of all cases defining the walls and enhancement of the lumen of the aorta. On the basis of criteria reported in the literature a five point subjective scale was used to grade image quality, from excellent (1) to non diagnostic quality(5). The reasons for degraded image quality were due to high BMI and consisted expecially in low signal/noise ratio and in two cases it was due to suboptimal contrast enhancement owing to poor bolus timing. In the cases of low signal/noise ratio a smooth filter was applied to reduce the noise The results of this study provide useful information about reduction of radation dose and medium iodined constrast. Diagnostic quality of scan performed with low dose of iodine and radiation are overlays with the scans performed with standard protocol. The study groups revealed a strong reduction dose in terms of DLP and quality of images was similar to the group of control.

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