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Document type:
journal article
Author(s):
Muenzel, D; Noel, PB; Dorn, F; Dobritz, M; Rummeny, EJ; Huber, A
Title:
Coronary CT angiography in step-and-shoot technique with 256-slice CT: Impact of the field of view on image quality, craniocaudal coverage, and radiation exposure.
Abstract:
To evaluate the effect of a small field of view (FOV) for step-and-shoot coronary computed tomography angiography (CCTA) on craniocaudal z-coverage per scan step, image quality, and radiation exposure.53 patients underwent prospectively ECG-gated CCTA on a 256-slice MDCT scanner using either a FOV>250mm (group 1, n=29) or a FOV<<=250mm (group 2, n=24). Craniocaudal z-coverage was determined on coronal multiplanar reformations. Image noise, signal-to-noise ratio, contrast-to-noise ratio, and qualitative image parameters were assessed. Radiation dose was estimated from the dose length product and was standardized for a scan range from the main pulmonary artery to the diaphragm in order to make both groups comparable.Diagnostic image quality was achieved in 91.3% of the coronary artery segments of group 1 and 89.9% in group 2 (p=0.201). There were no major differences in image noise, SNR, and CNR between both groups. A smaller FOV leads to an increase of craniocaudal coverage of a single CT scan step (r=-0.879; p<=0.001). There was an increase of 23.8% of the mean z-coverage per scanned subvolume in group 2 (59.9mm vs. 48.8mm). Radiation dose was significantly lower in group 2 (229 vs. 285mGycm, respectively).The use of a small transverse FOV for step-and-shoot CCTA at a wide detector CT scanner leads to an increased z-coverage. 2 scan volumes are enough to image the cardiac anatomy. Radiation dose is decreased without negative impact on image quality.
Journal title abbreviation:
Eur J Radiol
Year:
2012
Journal volume:
81
Journal issue:
7
Pages contribution:
1562-8
Language:
eng
Pubmed ID:
http://view.ncbi.nlm.nih.gov/pubmed/21561732
Print-ISSN:
0720-048X
TUM Institution:
Institut für Radiologie
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