Benefits of low-dose carotid CT angiography in stroke patients

Introduction: Computed tomography angiography (CTA) represents the gold standard as a method for the diagnosis of carotid artery diseases. The current topic is the use of CTA for the evaluation of carotid arteries with a reduction in the dose of contrast agent and dose of ionizing radiation, which, with adequate preparation, would enable the use of this method in some risk groups. The aim of this study was to evaluate the feasibility and image quality of a new low-dose CTA protocol in comparison with a standard protocol. Methods: Forty patients with recumbent ischemic stroke were included in the study, twenty of whom underwent lowdose CTA, and the remaining twenty underwent a standard CTA protocol of the carotid arteries. Results: No significant difference was found between the mean values of CT number (Hounsfield unit), signal-to-noise ratio, contrast-to-noise ratio, and subjective assessment of image quality in the comparison of the control and experimental groups. CT dose index, volume, and dose length product were significantly lower in patients who underwent lowdose carotid CTA. There was no significant difference in the degree of carotid stenosis between color Doppler and CTA. Conclusion: The use of the low-dose protocol for carotid CTA allows the application of this method in risk groups, in which it was previously not possible to perform, with the same image quality in comparison with the standard protocol

Relationship between ultrasonographically determined kidney volume and progression of chronic kidney disease

Aim To investigate a correlation between calculated creatinine clearance as a measure of kidney’s functional abilities and ultrasonographically determined kidney volume, which represents actual size of the kidney, in fact residual renal mass in chronic kidney disease, in order to determine possibilities of ultrasound as a diagnostic method in diagnosing and follow up of chronic renal disease. Methods Prospective study included 150 patients with registered demographic and anthropometric data, and also with relevant laboratory tests of renal function. Longitudinal diameter, thickness and width of the kidney and renal volume calculated according to the Dinkel’s formula were measured by ultrasound. A correlation between the measured volume of the kidneys and calculated creatinine clearance was done by the Spearman method, with statistical significance of p<0.05. Results Statistically significant correlation between the estimated creatinine clearance values and the average of the calculated values of kidney volume was found (p<0.01). Average value of the kidneys’ volume showed a linear decrease with the progression of chronic kidney disease: the kidney volume in the control healthy group was 171.7 ± 32.6 mL (95.22- 229.59 mL), and in the subjects classified in stage IV it was 74.7 ± 24.6 mL (43.22-165.65 mL). Conclusion Calculated volume of kidney well correlated with creatinine clearance as a measure of functional ability of the kidneys and with the stage of chronic renal disease. It can be used in clinical practice for monitoring of chronic kidney disease in conjunction with other clinical and laboratory parameters

Possibilities of differentiation of solitary focal liver lesions by computed tomography perfusion

Aim To evaluate possibilities of computed tomography (CT) perfusion in differentiation of solitary focal liver lesions based on their characteristic vascularization through perfusion parameters analysis. Methods Prospective study was conducted on 50 patients in the period 2009-2012. Patients were divided in two groups: benign and malignant lesions. The following CT perfusion parameters were analyzed: blood flow (BF), blood volume (BV), mean transit time (MTT), capillary permeability surface area product (PS), hepatic arterial fraction (HAF), and impulse residual function (IRF). During the study another perfusion parameter was analyzed: hepatic perfusion index (HPI). All patients were examined on Multidetector 64-slice CT machine (GE) with application of perfusion protocol for liver with i.v. administration of contrast agent. Results In both groups an increase of vascularization and arterial blood flow was noticed, but there was no significant statistical difference between any of 6 analyzed parameters. Hepatic perfusion index values were increased in all lesions in comparison with normal liver parenchyma. Conclusion Computed tomography perfusion in our study did not allow differentiation of benign and malignant liver lesions based on analysis of functional perfusion parameters. Hepatic perfusion index should be investigated in further studies as a parameter for detection of possible presence of micro-metastases in visually homogeneous liver in cases with no lesions found during standard CT protoco