New software technology has also been introduced to help manage the noise from CT images, allowing for lower radiation dose. For instance, adaptive statistical iterative reconstruction (ASIR) may allow for dose reductions of up to 66% in abdominal scans, with no changes required to spatial or temporal resolution.21 One recent study compared CT enterography with ASIR with standard reconstruction, concluding that in patients weighing less than 160 lbs, examinations at 80 kVp with 30% ASIR produced diagnostically acceptable images. The average CTDIvol in the study was 6.15 mGy, and the average effective dose was 4.60 mSv.22 More generally, technologists can individualize the examination and adjust the radiation dose to the body type and body organ under examination, as the imaging of different body types and organs require different amounts of radiation. Prior to every CT examination, technologists should evaluate the appropriateness of the examination, and determine whether another type of examination may be more suitable. Higher resolution imaging is not always suitable for every given scenario. For instance, the likelihood of detection of small pulmonary masses may not be increased with higher resolution imaging.
Ultimately, technologists and radiologists, as well as the referring clinicians ordering CT images, required an increased level of education to understand the risks and limitations of CT, as well as the clinical applications that are likely to provide the greatest benefit.
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