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Keywords:
Dosimetric comparison, Diagnostic procedure, CT, Radioprotection / Radiation dose, Oncology
Authors:
E. Lekgabe, N. Tran, W. Cheung, B. McDonald, H. Kavnoudias, L. Hudson, X. Chen; Melbourne/AU
DOI:
10.1594/ecr2015/C-1895
Results
- The average DLP for the research protocol was 669.70 mGy‧cm and 923.01 mGy‧cm for the conventional protocol,
equating to average effective doses of 12.46 mSv and 17.17 mSv respectively,
when using E/DLP conversion factor of 18.6 μSv/mGy cm(5) (Table 1).
This corresponds to a radiation dose reduction of 27.44%.
-
The image quality scores are provided in table 2.
There was poor Interobserver agreement between the two radiologists in regards to the individual scores,
with low kappa values.
However,
when looking at the combined mean score for the two scans (abdomen and mediastinum) there was no significant difference,
especially when considering that a score of 3 and above was regarded as good image quality.
-
In regards to the ease of the performing the research protocol scans by the radiographer,
no research protocol scan was graded as a 4 or 5,
meaning that they were not more difficult to perform than the conventional protocol scans.
The majority were graded as scores of 1 or 2,
and the remainder given scores of 3.
-
The mean attenuation values are shown in table 3.
The values are significantly different in the mediastinum; however this did not seem to impact on the image quality grades assigned by the radiologists.
The abdominal scores are not significantly different.
However,
whether the differences are statistically significant will depend on whether diagnostic accuracy is impacted.
Diagnostic accuracy was not investigated in this study.
None of the scans of the research protocol was required to be repeated due to poor image quality.
There were no adverse events suffered by the patients undergoing research protocol scans during the study period.