Image Quality, Contrast Enhancement, and Radiation Dose of ECG-Triggered High-Pitch CT Versus Non-ECG-Triggered Standard-Pitch CT of the Thoracoabdominal Aorta

Image Quality, Contrast Enhancement, and Radiation Dose of ECG-Triggered High-Pitch CT Versus Non-ECG-Triggered Standard-Pitch CT of the Thoracoabdominal Aorta

Bolen M A; Popovic Z B; Tandon N; Flamm S D; Schoenhagen P; Halliburton S S

American Journal of Roentgenology

2012

2012-04

OBJECTIVE. We sought to compare image quality, contrast enhancement, and radiation dose in patients undergoing ECG-triggered high-pitch helical CT or non-ECG-synchronized helical CT of the thoracoabdominal aorta. MATERIALS AND METHODS. We retrospectively assessed data from 101 consecutive patients (81 men, 20 women; mean age, 71 +/- 11 [SD] years) undergoing clinically indicated CT angiography (CTA) of the thoracoabdominal aorta on a dual-source scanner using either the ECG-triggered high-pitch helical mode (group 1, n = 52) or non-ECG-synchronized standard-pitch helical mode (group 2, n = 49) during the arterial phase. Two independent readers assessed image quality, noise, and contrast enhancement throughout the thoracoabdominal aorta. Scanner-reported dose-length product values were used to estimate effective dose values. RESULTS. Image quality at the root-proximal ascending level was higher in group 1 (mean +/- SD, 2.81 +/- 0.40) than in group 2 (1.22 +/- 0.47; p < 0.0001), with similar quality for both groups noted at other levels. Group 1 scans displayed higher image noise at all levels. The groups received a similar volume of contrast material (p = 0.77), and similar percentages of cases with acceptable contrast enhancement (> 250 HU) were noted in the two groups. The estimated radiation burden was significantly lower in group 1 (mean +/- SD, 5.4 +/- 1.8 mSv) than in group 2 (14.4 +/- 5.1 mSv; p < 0.0001). CONCLUSION. Imaging of the thoracoabdominal aorta with ECG-triggered high-pitch CTA provides higher quality images of the aortic root and ascending aorta with sufficient contrast enhancement and decreased estimated radiation dose compared with non- ECG-synchronized standard-pitch helical CT.

diagnosis; Radiology; Nuclear Medicine & Medical Imaging; aorta; reconstruction; heart-rate-variability; angiography; acquisition; CT angiography; dissection; dual-source ct; high pitch; source cardiac ct

Journal Article or Conference Abstract Publication

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931-938

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