R Iezzi1, A R Cotroneo, A Giammarino, F Spigonardo, M L Storto. 1. Department of Bioimaging and Radiological Sciences, Institute of Radiology, "A. Gemelli" Hospital - Catholic University, L.go A Gemelli 8, 00168 Rome, Italy. iezzir@virgilio.it
Abstract
PURPOSE: To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm. MATERIALS AND METHODS: In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement. RESULTS: Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p<0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p=0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63±6.97 vs. 11.48±8.13; p=0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol. CONCLUSION: In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.
PURPOSE: To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm. MATERIALS AND METHODS: In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement. RESULTS: Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p<0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p=0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63±6.97 vs. 11.48±8.13; p=0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol. CONCLUSION: In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.
Authors: R Motta; L Rubaltelli; R Vezzaro; V Vida; P Marchesi; R Stramare; A Zanon; M Battistel; M Sommavilla; D Miotto Journal: Radiol Med Date: 2012-03-19 Impact factor: 3.469