Can wide-volume CT improve pediatric head imaging? Insights from a newly fabricated anthropomorphic phantom and expert image-quality scoring.

Background

Wide-volume acquisition may reduce radiation exposure in pediatric head CT by limiting unnecessary z-axis irradiation, but evidence on 80-row detector systems remains limited. This study compared wide-volume and conventional helical acquisition using a newly fabricated patient-derived anthropomorphic pediatric head phantom and a retrospective clinical cohort.

Methods

The NZPH pediatric head phantom was scanned on an 80-row Canon CT system using matched helical and wide-volume protocols at 80, 100, and 120 kV with tube-current settings of 100, 150, 200, and 250 mA. Radiation output and quantitative image quality were compared across 12 matched settings. The clinical cohort comprised 84 consecutive retrospective non-contrast pediatric head CT examinations, including 42 helical and 42 wide-volume studies. Radiation dose, objective image-quality metrics, and six qualitative criteria were assessed; four radiologists independently performed image-quality scoring. Inter-reader agreement was evaluated using intraclass correlation coefficients.

Results

In the phantom experiment, wide-volume acquisition produced lower DLP across all 12 matched settings, with reductions of 38.2%-50.7%. In the clinical cohort, median DLP was 586 mGy·cm for helical acquisition and 347 mGy·cm for wide-volume acquisition, corresponding to a 40.8% reduction. Mean effective dose was 1.99 versus 1.09 mSv, respectively. Age-stratified DLP reductions ranged from 41.6% to 48.4%. Gray- and white-matter attenuation remained comparable, whereas wide-volume acquisition showed higher image noise (4.58 ± 0.49 vs 4.12 ± 0.39 HU; p < 0.001) and lower SNR and CNR. Despite lower qualitative scores than helical acquisition, wide-volume examinations remained diagnostically acceptable, with a mean overall acceptability score of 4.11 ± 0.49.

Conclusion

Wide-volume acquisition on an 80-row CT system was associated with substantial pediatric head CT dose reduction while maintaining clinically acceptable image quality, supporting its use as a practical dose-optimization strategy. PLAIN LANGUAGE SUMMARY CT scans of a child's head are useful for diagnosis, but reducing radiation exposure is an important part of safe imaging. This study compared a newer wide-volume CT scanning method with a conventional method using both a child-sized test model and scans from 84 children. This study found that the newer method reduced radiation dose by about 40% while still providing image quality that was considered suitable for diagnosis. This matters because lower-dose scanning methods may help improve radiation safety for children without reducing the clinical value of the examination.