Multislice CT angiography in aortic stent grafting: relationship between image noise and body mass index.
OBJECTIVE
To investigate the correlation between image noise and body mass index (BMI) in multislice CT angiography (MSCT) for patients with abdominal aortic aneurysm (AAA) treated with endovascular stent grafts.


METHODS
Seventeen patients who underwent MSCT following endovascular repair of AAA were included in the study. Image noise (standard deviation of the CT attenuation: S.D.) and signal to noise ratio (SNR) were plotted against BMI to demonstrate the correlation using a linear regression method. Image quality of 3D reconstructions was correlated to the SNR and BMI.


RESULTS
The r-value of linear regression between S.D. and BMI was 0.578 (p<0.05), 0.835 and 0.802 (p<0.001), respectively, at the level of renal artery, aortic aneurysm and common iliac artery. The r-value of linear regression between SNR and BMI was 0.332, 0.516 and 0.552 (p<0.05), respectively, at above three levels. Image quality of 3D reconstructions was compromised in five patients and diagnosis was affected in two patients with BMI more than 30.


CONCLUSIONS
A significant correlation was observed between image noise and BMI in MSCT angiography of endovascular repair of AAA. Our findings are valuable for optimisation of MSCT angiography scanning protocols and reduction of radiation dose in MSCT examinations.
Sun
Zhonghua
Z
Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987, Perth, Western Australia 6845, Australia. z.sun@curtin.edu.au
D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000628:therapy; D016477:Artifacts; D015992:Body Mass Index; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D015607:Stents; D014057:Tomography, X-Ray Computed