J Korean Soc Radiol.  2011 Nov;65(5):505-512.

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

• Cho YS
• Jeong WK
• Kim Y
• Heo JN

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.

MeSH Terms

Body Mass Index
Human Body
Humans
Kidney
Noise

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