Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Dec;199(6):1402-9.
doi: 10.2214/AJR.12.8652.

Radiation dose and image quality at high-pitch CT angiography of the aorta: intraindividual and interindividual comparisons with conventional CT angiography

Paul Apfaltrer  1 , E Lexworth Hanna, U Joseph Schoepf, J Reid Spears, Stefan O Schoenberg, Christian Fink, Rozemarijn Vliegenthart
Affiliations

Radiation dose and image quality at high-pitch CT angiography of the aorta: intraindividual and interindividual comparisons with conventional CT angiography

Paul Apfaltrer et al. AJR Am J Roentgenol. 2012 Dec.

Abstract

Objective: The objective of our study was to evaluate radiation dose and quantitative image quality parameters at high-pitch CT angiography (CTA) of the aorta compared with conventional CTA.

Materials and methods: We studied the examinations of 110 patients (65 men and 45 women; mean age ± SD, 64 ± 15 years) who had undergone CTA of the entire aorta on a second-generation dual-source CT system; 50 examinations were performed in high-pitch mode. The mean arterial attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) were calculated for the high-pitch CTA and conventional CTA groups. Radiation exposures were compared.

Results: All studies were considered of diagnostic quality. At high-pitch CTA, the mean tube voltage and tube current-exposure time product were 118 ± 7 kV (SD) and 197 ± 78 mAs compared with 120 ± 1 kV and 258 ± 78 mAs, respectively, at conventional CTA (p < 0.05). The mean volume CT dose index, dose-length product, and effective dose were 8.1 ± 2.4 mGy, 561.1 ± 178.6 mGy × cm, and 9.6 ± 3.0 mSv at high-pitch CTA and 18.3 ± 7.7 mGy, 1162.6 ± 480.1 mGy × cm, and 19.8 ± 8.2 mSv at conventional CTA (p < 0.001). Attenuation was similar for both protocols, whereas significantly less contrast medium was injected for high-pitch CTA than for standard-pitch CTA (87.3 ± 16 mL vs 97.9 ± 16 mL, respectively; p < 0.01). The SNR and CNR were significantly lower in the high-pitch CTA examinations (p < 0.01), whereas the FOM was nonsignificantly higher. Twenty patients underwent both high-pitch CTA and conventional CTA, with a 45% reduction in radiation dose (p < 0.001).

Conclusion: High-pitch CTA of the aorta yields 45-50% reduction of radiation exposure as well as contrast medium savings with maintained vessel attenuation.

PubMed Disclaimer