Standard image descriptors for the provisional molecular imaging reporting system (pMIRS) for thoracic tumors

Learning Objectives Teach reproducible qualitative image descriptors for structured reporting of thoracic PET/CT findings for the pMIRS, compliant with the RadLex reporting system of the RSNA.

Definitions of F-18 FDG-PET/CT avidity for the thorax: Normal = no increased avidity Slight = visibly abnormal, less than moderate Since pilot studies suggest most observer variance for intermediate findings,two independently proposed descriptors were included: Moderate L = comparable to normal liver (L), or Moderate M = comparable to mediastinal blood pool(M) Marked = comparable to or greater than cerebellum Electronic displays of multiple renditions simulated representative reading conditions including typical PET, PET-CT fusion, and CT renditions of each example. Twelve physicians, with varying experience, independently reviewed 15 select examples, with access to definitions, but not to quantitative SUV values. (K statistics were not applicable). Results : 1. The qualitative descriptors showed full ordinal conformity to quantitative SUV measurements for each finding. 2. The L definition of moderate uptake tended to improve inter-observer agreement. Conclusions : Simple definitions for subjective image findings descriptors teach reasonable interobserver agreement for application to PET/CT interpretations in thoracic tumors, potentially scalable to large outcomes studies

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Descriptor agreement among 12 observers of 15 tumors

Differing Liver(L),and Mediastinal blood(M) method to define moderate avidity.