Prospective safety evaluation of automated iomeprol 400 injections for CT through peripheral venous cannulas.

AIM: To evaluate prospectively the safety of contrast medium injection through standard peripheral intravenous cannulas at standard injection sites during clinical routine using iomeprol 400, a contrast agent with high viscosity. MATERIALS AND METHODS: Three thousand, five hundred and fourteen clinical CT examinations undertaken at Saarland University Medical Center were included in this prospective observational trial. The size and site of the cannula as well as the contrast medium injection rate and volume were assessed for each patient. In addition, the ability to aspirate blood though the cannula and the occurrence of complications, such as extravasation or abortion of injection by the automated injector, were recorded. RESULTS: The overall complication rate was 30/3,514 (0.85%). With 22 G cannulas, the complication rate was 8/541 (1.48%) applying flow rates of 1-3.5 ml/s (mean 2.1 ml/s). With 20 G cannulas, complications occurred in 21/2,601 cases (0.81%) with flow rates of 1.5-5 ml/s (mean 3 ml/s). The complication rate using 18 G cannulas was 1/377 (0.26%) for flow rates of 2-6 ml/s (mean 3.5 ml/s). No relationship between the site and size of the cannula to the occurrence of complications was found. The inability to aspirate blood correlated with the development of extravasation. CONCLUSIONS: The injection of contrast agent using standard peripheral venous cannulas is a safe and reliable procedure yielding diagnostic image contrast, even when using highly viscous contrast agents such as iomeprol 400; an aspiration test should be performed before each injection.

T1 Signal Measurements in Pediatric Brain: Findings after Multiple Exposures to Gadobenate Dimeglumine for Imaging of Nonneurologic Disease.

BACKGROUND AND PURPOSE: Signal intensity increases possibly suggestive of gadolinium retention have recently been reported on unenhanced T1-weighted images of the pediatric brain following multiple exposures to gadolinium-based MR contrast agents. Our aim was to determine whether T1 signal changes suggestive of gadolinium deposition occur in the brains of pediatric nonneurologic patients after multiple exposures to gadobenate dimeglumine. MATERIALS AND METHODS: Thirty-four nonneurologic patients (group 1; 17 males/17 females; mean age, 7.18 years) who received between 5 and 15 injections (mean, 7.8 injections) of 0.05 mmol/kg of gadobenate during a mean of 2.24 years were compared with 24 control patients (group 2; 16 males/8 females; mean age, 8.78 years) who had never received gadolinium-based contrast agents. Exposure to gadobenate was for diagnosis and therapy monitoring. Five blinded readers independently determined the signal intensity at ROIs in the dentate nucleus, globus pallidus, pons, and thalamus on unenhanced T1-weighted spin-echo images from both groups. Unpaired t tests were used to compare signal-intensity values and dentate nucleus-pons and globus pallidus-thalamus signal-intensity ratios between groups 1 and 2. RESULTS: Mean signal-intensity values in the dentate nucleus, globus pallidus, pons, and thalamus of gadobenate-exposed patients ranged from 366.4 to 389.2, 360.5 to 392.9, 370.5 to 374.9, and 356.9 to 371.0, respectively. Corresponding values in gadolinium-based contrast agent-naïve subjects were not significantly different (P > .05). Similarly, no significant differences were noted by any reader for comparisons of the dentate nucleus-pons signal-intensity ratios. One reader noted a difference in the mean globus pallidus-thalamus signal-intensity ratios (1.06 ± 0.006 versus 1.02 ± 0.009, P = .002), but this reflected nonsignificantly higher T1 signal in the thalamus of control subjects. The number of exposures and the interval between the first and last exposures did not influence signal-intensity values. CONCLUSIONS: Signal-intensity increases potentially indicative of gadolinium deposition are not seen in pediatric nonneurologic patients after multiple exposures to low-dose gadobenate.

A scoring system for the assessment of angiographic findings in non-occlusive mesenteric ischemia (NOMI).

PURPOSE: To establish a standardized scoring system for angiographic findings in patients with non-occlusive mesenteric ischemia (NOMI). MATERIALS AND METHODS: In 36 patients (mean age: 72 years), 53 angiographies of the superior mesenteric artery (SMA) were performed for suspected NOMI after cardiac or major aortic surgery. All examinations were performed using a standardized DSA technique. Two experienced radiologists performed a consensus reading blinded to the clinical information, on two occasions with an interval of two weeks. In order to investigate the reproducibility of the criteria, the images were assessed once by an intensivist and a medical student. Image analysis was performed with respect to vessel morphology, reflux of contrast medium into the aorta, small bowel parenchymal contrast enhancement and distension and the delay between arterial injection and portal vein filling. RESULTS: Almost perfect intra-observer correlation was obtained for the assessment of the contrast medium reflux (κ = 0.82) and substantial correlation for the time of portal vein filling (κ = 0.66). Moderate correlations were obtained for the vessel morphology (κ = 0.51), small bowel enhancement (κ = 0.63) and distension (κ = 0.53). Contrast medium reflux into the aorta (κ = 0.77 and 0.63) and the time of portal vein filling (κ = 0.42 and 0.58) resulted in the highest inter-observer correlations between the radiologists and the intensivist as well as the radiologists and the student. CONCLUSION: In patients with suspected NOMI, using our scoring system yields high intra- and inter-observer correlations, allowing a standardized evaluation of angiographic findings.