ABSTRACT: High heart rates and radiation sensitivity have limited the use of coronary computed tomography angiography (CTA) in pediatric patients.
A contemporary evaluation of image quality and reduction in radiation exposure with dual-source CT technology has not been reported in a large cohort of pediatric patients undergoing coronary angiography.
Consecutive coronary CTA scans (n = 71) in 70 pediatric patients were retrospectively reviewed. Metoprolol was administered for heart rate control. Scans were divided by acquisition mode into 3 groups: retrospective electrocardiogram (ECG)-triggered spiral, prospective ECG-triggered, and prospective ECG-triggered high-pitch spiral scans. Heart rate, radiation dose, image quality, and diagnostic confidence were compared between groups.
Median decrease in heart rate with metoprolol was 24% ± 14%. Median effective age-adjusted radiation dose for the entire group was 0.97 ± 1.20 mSv. Retrospective ECG-triggered scans had a median dose of 1.71 ± 1.4 mSv, prospectively ECG-triggered scans had a median dose of 0.9 ± 1.1 mSv, and prospectively ECG-triggered high-pitch spiral scans had a median effective dose of 0.27 ± 0.4 mSv. The difference between groups was statistically significant (P < 0.05). The contrast-to-noise ratio and the image quality score were similar between groups.
Dual-source coronary CTA with a β-blocker protocol uniformly achieves diagnostic coronary scans at a low radiation dose in pediatric patients. Image quality and diagnostic confidence are excellent for all scan modes in a wide spectrum of patients.
Journal of cardiovascular computed tomography 07/2012; 6(4):252-9.
ABSTRACT: Pediatric cardiac patients often undergo repeat diagnostic testing, resulting in relatively high cumulative medical radiation exposure. Low-dose CT scanning techniques used to decrease radiation exposure may result in reduced image quality.
This study evaluates a prototype iterative reconstruction algorithm, sinogram-affirmed iterative reconstruction (SAFIRE), to determine the effect on qualitative and quantitative measures of image quality in pediatric cardiac CT datasets, compared with a standard weighted filtered back projection (wFBP) algorithm.
Seventy-four datasets obtained on a 128-slice dual-source CT system were evaluated for image quality using both the wFBP and the prototype iterative reconstruction algorithm. Contrast, noise, contrast-to-noise ratio, signal-to-noise ratio, and qualitative image quality were compared between groups. Data were analyzed as medians and 25th and 75th percentiles, and groups were compared with the use of the Wilcoxon singed-rank test or k sample equality of medians test.
There was a 34% decrease in noise, a 41% increase in contrast-to-noise ratio, and a 56% increase in signal-to-noise ratio in the prototype iterative reconstruction, compared with wFBP. All differences were statistically significant (P < 0.001). Qualitative measures of image noise and noise texture were also improved in the iterative reconstruction group (P < 0.001 for both). Diagnostic confidence was similar between reconstruction techniques. Median scan dose length product was 15.5 mGy · cm.
The prototype iterative reconstruction algorithm studied significantly reduces image noise and improves qualitative and quantitative measures of image quality in low-dose pediatric CT datasets, compared with standard wFBP.
Journal of cardiovascular computed tomography 05/2012; 6(3):200-4.
ABSTRACT: Multidetector computed tomographic angiography defines anatomy in complex congenital heart disease, but radiation exposure and general anesthesia requirements limit its application. The aim of this study was to compare radiation exposure, anesthesia use, and diagnostic accuracy between standard-pitch, single-source computed tomography and high-pitch, dual-source computed tomography for image quality and risk in a clinical pediatric population. Consecutive computed tomographic scans were evaluated in patients aged <2 years with complex congenital heart disease. Two groups were compared on the basis of standard- versus high-pitch scans. High-pitch scans were further divided into variable pitch (2.25 to 3.0) and highest pitch (3.4) groups. Image quality, radiation exposure, anesthesia use, and diagnostic confidence and accuracy were determined. Sixty-one scans were reviewed (29 at standard pitch, 32 at high pitch). Body surface area, scan length, and indications were similar. The median dose-length product for standard-pitch scans was 66 mGy · cm (range 29 to 372) compared to 7 mGy · cm (range 3 to 50) in all high-pitch scans. The median dose-length product was 28 mGy · cm (range 8 to 50) for variable high-pitch scans and 5 mGy · cm (range 3 to 12) for the highest fixed-pitch scans. Diagnostic confidence was similar, although high-pitch scans had higher image noise and lower contrast-to-noise ratios. All high-pitch scans were performed under sedation with free breathing, and all standard-pitch scans required general anesthesia. Diagnostic accuracy was 100% in the 2 groups, with 17 standard-pitch and 16 high-pitch patients undergoing procedural validation. In conclusion, high-pitch, dual-source computed tomography provides excellent diagnostic accuracy and markedly reduces radiation dose, although image quality is mildly reduced.
The American journal of cardiology 05/2011; 107(10):1541-6. · 3.58 Impact Factor