Study group

The first phase of our study was to collect the records of every neck carotid CTA performed in the Affidea Diagnostics Hungary Ltd. Szeged during 2013. Among them, 512 examinations were performed retrospectively. Then the illnesses of the patients were investigated precisely with the help of the hospital informatics system Medsolution (International System House (ISH) Ltd. - Budapest, Hungary). In all, 150 patients were found with sufficient information relative to the study. Some diseases influence the size of the CB, including lesions of the liver (e.g., liver cirrhosis, hepatitis) and haematologic or metabolic diseases (e.g., lactate acidosis and haemoglobinopathy). As only two patients suffered from liver cirrhosis, it was not enough for statistical analysis, so we excluded them from the study. Exclusionary haematologic diseases or lactate acidosis could not be verified in any of the patients.  In seven cases, we found more than two of the examined illnesses. Finally, 141 patients met the previously determined criteria and were classified according to their conditions. There were 16 controls. HT alone was identified in 96 patients, HT associated with AMI in 12 patients, HF and HT in 9 patients, and COPD associated with HT in 8 patients. All patients who suffered from HT had essential HT. Detailed information about the study group is given in Table 1.

Measurement and evaluation

The examinations were performed using a 64-slice GE LightSpeed VCT XTe CT Scanner (General Electric - Fairfield, Connecticut, USA). The slices were obtained in helical mode with 1.25 mm slice thickness. Patients were scanned from the aortic arch to the frontal sinus. The contrast agent (Omnipaque 350 - General Electric - Fairfield, Connecticut, USA) was injected intravenously via an 18-gauge peripheral venous catheter. We used 50 ml contrast material for each examination. We first administered 15 ml of contrast agent at a rate of 2.5 ml/s rate and then 35 ml at a rate of 3.0 ml/s, followed by a 25-ml saline flush. We managed the process with the Smart prep technique.

One of the authors (SCS), who was unaware of the clinical conditions of the patients, executed the identification and measurement of the CB twice at different times. An axial scan was chosen for evaluation in each case because the CB could be best identified on axial scans. We used magnification if necessary. The same radiologist (SCS) who had identified the CBs measured the anteroposterior and latero-lateral diameters on both sides on two occasions. After it we got the area than the two measurements were averaged and used as the final data. Figures 1 and 2 show the identification and the measurement process. Figures 3, 4, 5 and 6 show examples from the examined groups.

Statistical analysis

The analysis and evaluation of the data were performed with the help of the Sigmaplot software package (version 13; Systat Software Company Inc., San Jose, CA, USA). The Shapiro-Wilk test was used to test data for normality. The Kruskal-Wallis one-way analysis of variance on ranks tests was executed to compare the results of all of the groups with each other, with p<0.05 indicating significance. Dunn’s multiple comparison procedure was applied to compare the groups. We also compared the measured data of the two measurement series (intra-observer variability) with the help of the Wilcoxon test.