Repeat rate analysis　is federally (USA) mandated in mammography and recommended by both the federal government and the American Association of Physicists in Medicine in Radiography (AAPM).[1,2,3] For the tomographic modalities (i.e. MRI, PET, CT) no repeat/reject metric exists. Repeats are usually the fault of technologists, faulty protocols, or uncooperative patients. Repeats/rejects often represent waste or deficiencies such as decreased scanner utilization, poor technologist training, poor CT protocols, wasted Iodine contrast, increased patient ionizing dose, and decreased patient satisfaction. Figure　1reviews the causes, effects and...

We built a pattern recognition algorithm to automatically detect repeats using an informatics solution. IT solution automatically calculates repeat rate IT solution requires no manual identification of repeats by technologists or radiologists IT solutions learns from a site's own practice patterns, making it capable of be deployed across a center with many different locations The method uses standard DICOM metadata, direct vendor enabled connection to modality units is therefore not required. Our method requires: scan mode (i.e., axial/sequential, helical/spiral, scout/topogram, etc.), scanner protocol name, accession...

Figures4 and5 depict the results of applying a repeat rate analysis to two different imaging centers. Figure4 quantifies the repeat rates while Figure5 quantifies effective dose differences for exams with and without a　 tomographic (i.e. axial or helical scan) repeat. Repeat rates at the sites we studied are much lower than those reported for radiography and mammography[3] Effective dose increases are actually more than double for exams containing repeats. We believe they average over 100% increase because larger patients tended to be more likely to...

T. Szczykutowicz Ph.D.; Associate Professor University of Wisconsin Madison Madison, WI/US - Advisory Board at iMALOGIX - Consultant at GE Healthcare - Research/Grant Support at GE Healthcare - Founder at protocolshare.org, consultant Takeda Pharmaceuticals. S. Rose Ph.D.;Medical Physics Resident Madison/US - nothing to disclose

[1] 21 CFR §900.12(e)(3)(ii). 2018 [2] 21 CFR §1000.55. 2018 [3] Jones PK, Heintz P, Geiser W, et al. Ongoing quality control in digital radiography: report of AAPM Imaging Physics Committee Task Group 151. Med Phys. 2015;42:6658-70 [4] Szczykutowicz TP, Malkus A, Ciano A, Pozniak M. Tracking patterns of nonadherence to prescribed CT protocol parameters.　J Am Coll Radiol.　2017;14:224-30 [5] Siegelman JR, Gress DA. Radiology stewardship and quality improvement: the process and costs of implementing a CT radiation dose optimization committee in a medium-sized...