Radiation Doses of Dual-Energy CT for Abdominopelvic CT: Comparison with Single-Energy CT

Young Seo Cho; Woo Kyoung Jeong; Yongsoo Kim; Jeong Nam Heo

doi:10.3348/jksr.2011.65.5.505

Journal List > J Korean Soc Radiol > v.65(5) > 1087037

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Cho, Jeong, Kim, and Heo: Radiation Doses of Dual-Energy CT for Abdominopelvic CT: Comparison with Single-Energy CT

Abdominal Radiology

Original Article

Journal of the Korean Society of Radiology 2011; 65(5): 505-512.

Published online: 30 November 2011

DOI: https://doi.org/10.3348/jksr.2011.65.5.505

Radiation Doses of Dual-Energy CT for Abdominopelvic CT: Comparison with Single-Energy CT

Young Seo Cho, MD, Woo Kyoung Jeong, MD, Yongsoo Kim, MD, Jeong Nam Heo, MD

Department of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.

Corresponding author: Woo Kyoung Jeong, MD. Department of Radiology, Hanyang University Guri Hospital, 249-1 Gyomun-dong, Guri 471-701, Korea. Tel. 82-31-560-2592, Fax. 82-31-560-2551, jeongwk@hanyang.ac.kr

Received 3 August 2011 Accepted 2 September 2011

Abstract

Purpose

To compare radiation doses of dual-energy CT (DECT) to single-energy CT (SECT) by a phantom experiment, with the application of mean tube currents for abdomino-pelvic CT.

Materials and Methods

This study includes patients who were examined by contrast-enhanced CT for kidney evaluation. We divided the patients into six groups according to sex and body mass index. Each group consisted of five patients and a total of 30 patients were evaluated. We split the body parts (abdomen and pelvis), and calculated the mean tube current of each group as well as investigated the image noise. Applying the mean mAs from a CT scan, we measured the weighted CT dose index (CTDIw) of DECT and SECT. We compared the measured CTDIw to an estimated CTDI value displayed on the CT console. We also compared the radiation dose ratio of DECT to SECT (D/S ratio) for each subgroup. The radiation doses were compared by the student's t-test and analysis of variance.

Results

The difference of image noise between DECT and SECT was not statistically significant. Radiation dose of DECT was higher than SECT by about 21.6% (10.69 mGy, 8.79 mGy; p < 0.0001), and the measured CTDI of the DECT was significantly higher than the estimated CTDI by about 6% (p < 0.001). The D/S ratio was not significant between the six groups.

Conclusion

The measured CTDIw of abdominopelvic DECT studies were significantly higher than those of SECT.

Keywords: Dual-Energy CT, Radiation Dose, Weighted CT Dose Index, Body Mass Index

Figures and Tables

Table 1

Body Mass Indexes of Each Subgroups

Note.-BMI = body mass index

Table 2

Mean Tube Current of 6 Subgroups in DECT and SECT Scans

Note.-Abd = abdomen, BMI = body mass index, DECT = dual energy CT scan, Pel = pelvis, SECT = single energy CT scan

Table 3

Measured Weighted CT Dose Indexes (CTDIw) in Subgroups

Note.-BMI = body mass index, DECT = dual energy CT scan, D/S Ratio = Ratio of the dose of dual-energy CT scan to that of single-energy CT scan, SECT = single energy CT scan

Table 4

Comparison Between Measured and Estimated CT Dose Indexes (CTDI)

Note.-BMI = body mass index, DECT = dual energy CT scan, SECT = single energy CT scan

Table 5

D/S Ratio in Subgroups

Note.-BMI = body mass index, D/S Ratio = Ratio of the dose of dual-energy CT scan to that of single-energy CT scan

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