Dual-step prospective ECG-triggered 128-slice dual-source CT for evaluation of coronary arteries and cardiac function without heart rate control: a technical note

Purpose: To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECGdual_step) for evaluation of coronary arteries and cardiac function. Methods: Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECGdual-step) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65bpm/70% RR interval <65bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated. Results: Mean HR was 68bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p = 0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p < 0.001) and more segments with impaired image quality (p < 0.001 and p = 0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6mAs (p < 0.001). The average radiation dose was 3.8mSv (range, 1.7-7.9) in patients in SR. Conclusion: pECGdual-step128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dos

Dual-energy CT with tin filter technology for the discrimination of renal lesion proxies containing blood, protein, and contrast-agent. An experimental phantom study

Purpose: To differentiate proxy renal cystic lesions containing protein, blood, iodine contrast or saline solutions using dual-energy CT (DECT) equipped with a new tin filter technology (TFT). Materials and methods: 70 proxies (saline, protein, blood and contrast agent) were placed in unenhanced and contrast-enhanced kidney phantoms. DECT was performed at 80/140kV with and without tin filtering. Two readers measured the CT attenuation values in all proxies twice. An 80/140kV ratio was calculated. Results: All intra- and interobserver agreements were excellent (r = 0.93-0.97; p  0.05). The CT attenuation of protein, blood and contrast agent solution differed significantly with tin filtering (p < 0.01-0.05). Significant differences were found between the ratios of protein and blood compared to contrast medium solution (each, p < 0.05) and between the ratios of protein and blood in both phantoms with tin filtering (each, p < 0.05). Conclusion: DECT allows discrimination between a proxy renal lesion containing contrast agent and lesions containing protein and blood through their different attenuation at 80kV and 140kV. Further discrimination between protein and blood containing proxies is possible when using a tin filte

Dual-energy CT with tin filter technology for the discrimination of renal lesion proxies containing blood, protein, and contrast-agent. An experimental phantom study

PURPOSE: To differentiate proxy renal cystic lesions containing protein, blood, iodine contrast or saline solutions using dual-energy CT (DECT) equipped with a new tin filter technology (TFT). MATERIALS AND METHODS: 70 proxies (saline, protein, blood and contrast agent) were placed in unenhanced and contrast-enhanced kidney phantoms. DECT was performed at 80/140 kV with and without tin filtering. Two readers measured the CT attenuation values in all proxies twice. An 80/140 kV ratio was calculated. RESULTS: All intra- and interobserver agreements were excellent (r = 0.93-0.97; p 0.05). The CT attenuation of protein, blood and contrast agent solution differed significantly with tin filtering (p < 0.01-0.05). Significant differences were found between the ratios of protein and blood compared to contrast medium solution (each, p < 0.05) and between the ratios of protein and blood in both phantoms with tin filtering (each, p < 0.05). CONCLUSION: DECT allows discrimination between a proxy renal lesion containing contrast agent and lesions containing protein and blood through their different attenuation at 80 kV and 140 kV. Further discrimination between protein and blood containing proxies is possible when using a tin filter

Dual-step prospective ECG-triggered 128-slice dual-source CT for evaluation of coronary arteries and cardiac function without heart rate control: a technical note

PURPOSE: To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECG(dual_step)) for evaluation of coronary arteries and cardiac function. METHODS: Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECG(dual-step)) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65 bpm/70% RR interval <65 bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated. RESULTS: Mean HR was 68 bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p = 0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p < 0.001) and more segments with impaired image quality (p < 0.001 and p = 0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6 mAs (p < 0.001). The average radiation dose was 3.8 mSv (range, 1.7-7.9) in patients in SR. CONCLUSION: pECG(dual-step)128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dose