Dose and image quality in CT pulmonary angiography: Comparison of Dual-Source CT, third generation Dual-Energy CT and conventional 64-slice spiral CT

Congress:

ESCR 2016

Poster Number:

P-0018

Type:

Scientific Poster

Keywords:

Cardiovascular system, CT-Angiography, Contrast agent-intravenous, Dosimetry, Dosimetric comparison

Authors:

A. Kosmala, T. Gassenmaier, S. Veldhoen, A. Kunz, T. A. Bley, B. Petritsch; Würzburg/DE

DOI:

DOI-Link:

https://dx.doi.org/

Fig. 1: Axial blended virtual 120 kV angiographic image indicates segmental PE (arrow).

Fig. 2: Axial reconstruction visualizes wedge-shaped perfusion defect in the...

Fig. 3: Coronar reconstruction visualizes wedge-shaped perfusion defect in the...

Purpose

To compare radiation dose and image quality of turbo high-pitch dual-source computed tomography (DSCT), dual-energy CT (DECT) and conventional single-source spiral CT (SSCT) for pulmonary CT angiography (CTA) on a 3rd generation dual-source CT, respectively a 64-slice CT system.

Methods and Materials

Prospectively atotal of 120 patients matched for sex, age, and body-mass-index were identified for this study and divided in three groups of 40 patients each. CTDIvol, DLP, subjective image quality as assessed by two readers (five-point scale: 1 = excellent; 2 = good; 3 = moderate; 4 = poor; 5 = non-diagnostic), measured CT attenuation (HU) in three central and peripheral levels, background noise (BN) and calculated signal-to-noise-ratio (SNR) were compared. CT protocol settings of each patient group were chosen according to the manufacturer’s recommendations:...

Results

Mean CTDIvol and DLP were significantly lower (CTDIvol: 1 vs. 3: p<0.001; 2 vs. 3: p=0.002 / DLP: 1 vs. 3: p<0.001; 2 vs. 3: p<0.001) in group 3 (4.49±1.48 mGy / 161±55 mGycm) compared to group 1 (7.45±2.72 mGy / 252±96 mGycm) and group 2 (6.46±3.72 mGy / 228±136 mGycm). Subjective image quality was rated good to excellent in >91% (110/120) with an interreader agreement of 90.3%. The three protocols did not significantly differ in subjective image quality. While group 3 presented with higher...

Conclusion

The use of third generation DECT in 90/Sn150 kV configuration allows for significant dose reduction in pulmonary CTA while providing excellent image quality and potential additional information by means of iodine perfusion maps (Figures 1 - 3).

References

Remy-Jardin M, Pistolesi M, Goodman LR, et al. Management of suspected acutepulmonary embolism in the era of CT angiography: a statement from the Fleischner Society. Radiology. 2007;245:315–329. Johnson TRC, Krauss B, Sedlmair M, et al. Material differentiation by dual energy CT: initial experience. Eur Radiol. 2007;17:1510–1517. Thieme SF, Johnson TRC, Lee C, et al. Dual-energy CT for the assessment of contrast material distribution in the pulmonary parenchyma. Am J Roentgenol. 2009;193:144–149. Bauer RW, Kerl JM, Weber E, et al. Lung perfusion analysis with dual energy...