Radiologist compliance with California CT dose reporting requirements: a single-center review of pediatric chest CT

Patient-level dose monitoring in computed tomography: tracking cumulative dose from multiple multi-sequence exams with tube current modulation in children

BACKGROUND

In children exposed to multiple computed tomography (CT) exams, performed with varying z-axis coverage and often with tube current modulation, it is inaccurate to add volume CT dose index (CTDI_vol) and size-specific dose estimate (SSDE) to obtain cumulative dose values.

OBJECTIVE

To introduce the patient-size-specific z-axis dose profile and its dose line integral (DLI) as new dose metrics, and to use them to compare cumulative dose calculations against conventional measures.

MATERIALS AND METHODS

In all children with 2 or more abdominal-pelvic CT scans performed from 2013 through 2019, we retrospectively recorded all series kV, z-axis tube current profile, CTDI_vol, dose-length product (DLP) and calculated SSDE. We constructed dose profiles as a function of z-axis location for each series. One author identified the z-axis location of the superior mesenteric artery origin on each series obtained to align the dose profiles for construction of each patient's cumulative profile. We performed pair-wise comparisons between the peak dose of the cumulative patient dose profile and ΣSSDE, and between ΣDLI and ΣDLP.

RESULTS

We recorded dose data in 143 series obtained in 48 children, ages 0-2 years (n=15) and 8-16 years (n=33): ΣSSDE 12.7±6.7 and peak dose 15.1±8.1 mGy, ΣDLP 278±194 and ΣDLI 550±292 mGy·cm. Peak dose exceeded ΣSSDE by 20.6% (interquartile range [IQR]: 9.9-26.4%, P<0.001), and ΣDLI exceeded ΣDLP by 114% (IQR: 86.5-147.0%, P<0.001).

CONCLUSION

Our methodology represents a novel approach for evaluating radiation exposure in recurring pediatric abdominal CT examinations, both at the individual and population levels. Under a wide range of patient variables and acquisition conditions, graphic depiction of the cumulative z-axis dose profile across and beyond scan ranges, including the peak dose of the profile, provides a better tool for cumulative dose documentation than simple summations of SSDE. ΣDLI is advantageous in characterizing overall energy absorption over ΣDLP, which significantly underestimated this in all children.

Impact of California Computed Tomography Dose Legislation: Survey of Radiologists

INTRODUCTION

Highly publicized accounts of radiation overdose from computed tomography (CT) in both children and adults prompted legislation in California regulating CT dose. The purpose of this study was to determine the impact of the law (codified in Senate Bill [SB] 1237) on California radiologist practice patterns and understanding of CT dose.

MATERIALS AND METHODS

All radiologist members of the California Radiological Society were surveyed in August-September 2013. Questions gauged radiologists' familiarity with and attitudes toward the law, awareness of CT dose, and changes in practice following the law's enactment.

RESULTS

Of 1,300 surveyed, 138 (11%) responded; 132 of 137 (96%) were familiar with SB 1237. Of 135 responding, 126 and 115 (93% and 85%, respectively) knew to report CT dose index volume and dose-length product. Sixty of 134 (45%) attributed dose reporting to an increased awareness of appropriate dose ranges. Twenty-nine of 133 (22%) had modified protocols in concert with SB 1237s enactment. Of 31 responding, 5 (16%), 23 (74%), and 3 (74%) had modified protocols in only children, both adults and children, and only adults, respectively. Twenty-four of 129 (19%) utilized automated dose reporting; 48 (37%) and 57 (44%) used dictation/transcription and template-assisted voice recognition, respectively. Forty of 134 (30%) noted delays finalizing CT reports.

CONCLUSIONS

Most radiologists who responded in our sample were familiar with SB 1237. Nearly half attributed dose reporting to an increased awareness of appropriate dose ranges. Almost one quarter indicated protocol modifications, the majority including children, occurring in conjunction with the law. Reporting inefficiency was a common concern.