The Impact of Warmed Intravenous Contrast Material on the Bolus Geometry of Coronary CT Angiography Applications

Objective This study was designed to investigate the effect of administration of warmed contrast material (CM) on the bolus geometry and enhancement as depicted on coronary CT angiography. Materials and Methods A total of 64 patients (42 men, 22 women; mean age, 56 years) were randomly divided into two groups. Group 1 included 32 patients administered CM (Omnipaque [Iohexol] 350 mg I/ mL; Nycomed, Princeton, NJ) saline solutions kept in an incubator at a constant temperature (37℃). Group 2 included 32 patients administered the CM saline solutions kept at constant room temperature (24℃). Cardiac CT scans were performed with a dual source computed tomography (DSCT) scanner. For each group, region of interest curves were plotted inside the ascending aorta, main pulmonary artery and descending aorta on test bolus images. Using enhancement values, time/enhancement diagrams were produced for each vessel. On diagrams, basal Hounsfield unit (HU) values were subtracted from sequentially obtained values. A value of 100 HU was accepted as a cut-off value for the beginning of opacification. The time to peak, the time required to reach 100 HU opacification, maximum enhancement and duration of enhancement above 100 HU were noted. DSCT angiography studies were evaluated for coronary vessel enhancement. Results Maximum enhancement values in the ascending aorta, descending aorta and main pulmonary artery were significantly higher in group 1 subjects. In the ascending aorta, the median time required to reach 100 HU opacification during the test bolus analysis was significantly shorter for group 2 subjects than for group 1 subjects. In the ascending aorta, the descending aorta and main pulmonary artery, for group 1 subjects, the bolus geometry curve shifted to the left and upwards as compared with the bolus geometry curve for group 2 subjects. Conclusion The use of warmed CM yields higher enhancement values and a shorter time to reach maximum enhancement duration, resulting in a shift of the bolus geometry curve to the left that may provide optimized image quality.PubMedWoSScopu

Using computer based data acquisition and analysis system for nasal potential difference measurement in cystic fibrosis.

Nasal potential difference (PD) measurement has been used as a diagnostic test for cystic fibrosis (CF). It has been shown that large differences in reproducibility of nasal PD measurement can exist between different study sites. These differences reduce the validity of studies. In our study we tried to measure nasal PD values for a group of Turkish CF patients by using a computer based data acquisition system, which could eliminate the bias due to using different voltmeters. The CF group (n=40, mean age 9.3 years) value was -39.21+/-1.74 mV, and the control group (n=36, mean age 17.08 years) value was -18.24+/-1.48 mV (mean+/-SEM). Using the electronic data acquisition and analysis systems gave reliable results with high specificity (92%), sensitivity (79%), positive predictive value (95%) and negative predictive value (72%). Computer based data acquisition and analysis system provides suitable monitoring and continuous recording during measurements and facilitates repeat readings at the same distances along the nasal floor. Using electronic data acquisition may help to minimize the subjectivity in voltmeter measurements and hand analysis