Comparison of Fractionated vs Single bolus iodine contrast agent injection techniques in the CTA study of the Complete Aorta with 64-slices CT scanner. Preliminary results on the experience of the Radiographers/Nursing team of the Magliano Sabina, ASL Rieti

Abstract

Introduction: the technological evolution occurred in the last years of CT scanners , Contrast Agent molecules, analysis software and Vascular Post - Processing have allowed on the one hand to perform more and more dynamic Angio CT examinations with high Temporal Resolution but on the other hand they have imposed new technical challenges to the whole radiological team to optimize the study and try to obtain studies with suitable and homogeneous vascular enhancement throughout the Aorta. The ever-increasing Interventional Radiology, Vascular Surgery, and Interventional Cardiology activities involving the Aorta require increasingly optimal CT Angio imaging. Therefore it is important in order to have optimal CT Angio imaging that the enhancement is homogeneous from the aortic root up to the branch of the femoral a.femora in order to allow certain analysis and measurements over the whole volume studied. It is therefore important to acquire the examination with the most suitable tomographic technique, with the right volume administration of Contrast Agent, and with the most suitable injection technique in order to obtain optimal and homogeneous vascular enhancement throughout the Aorta  

Purpose: the aim of our study is to compare and analyze two different Contrast Agent injection techniques in the CT study of the Complete Aorta to understand which one is more suitable to achieve homogeneous enhancement of the whole aorta using a 64-slice CT scanner. The two techniques we used are the Single Bolus Technique in which the injection of the Contrast Agent is done in a single bolus at a constant rate and the Fractionated Bolus Technique in which the injection of the Contrast Agent is done in two fractionated boluses (30% of the volume at 3.5ml/sec - 70 of the volume at 3.0ml/sec)  

Materials and Methods: we examined a total of 30 patients (18M-60%/12F-40%) who had a Complete Aorta CTA examination from March 2023 to July 2024 (15 months) at the Magliano Sabina Health House Imaging Diagnostic Department of District 2 Salario Mirtense of the ASL of Rieti. The total study sample has a mean age of 65.83aa (+28.17/- 25.83aa - median value 66aa), a mean height of 169.13cm (+17.87/-14.13cm - median value 170cm), a mean weight of 76.93Kg (+22.07/-21.93Kg - median value 75kg) and a mean BMI of 27.01 (+10.34/-6.18BMI/mean value 25.42BMI). The total study sample is divided into two study arms. The Experimental Arm in which we used the Fractionated Bolus Injection technique consisted of 15 patients (8M/7F) with mean age 66.06aa (+27.94/- 23.06aa - median value 65aa), mean height 167cm (+12/-12cm - median value 170cm), mean weight 74.13Kg (+20.9/-19.1kg - median value 75Kg) and mean BMI of 26.67 (+5.38/- 5.84 BMI - median value 25.39 BMI). The Control Arm in which we used the Single Bolus Injection technique consisted of 15 patients (10M/5F) with mean age 70.5aa (+12.5/-30.5aa - median value 67aa), mean height 173.5cm (+13.5/-18.5cm - median value 170cm), mean weight 82.5Kg (+16.5/-22.5kg - median value 80Kg) and mean BMI of 27.49 (+12.05/-6.04BMI - median value 25.45 BMI). The following variables were evaluated for each study sample:Volume of injected Contrast Agent, Homogeneity of enhancement ,Dose Leght Product (DLP), quality of VR-3D imaging. All Complete Aorta CT Angio studies were performed :with Philips Ingenuity 64-Slice equipment from Philips, Automatic 3-channel CT Exprès injector from Bracco and reconstructed with Philips IntelliSpace Portal WorkStation. For all examinations in our study, we used a nonionic Iodine Contrast Agent with concentration 400mgI/ml 

Conclusions: the preliminary results of our study suggest how the use of Fractionated Bolus  injection technique Iodine Contrast Agent in CT Angio study of the Complete Aorta with 64-Slice CT scanner is indicated and strongly indicated in patients with height ≥175cm to achieve homogeneous and optimized CT imaging throughout the Aorta.