A National County-Level Typology of Imaging Infrastructure and the Radiologist Workforce in the United States.

Abstract

Rationale and objectives: This study aimed to perform a national county-level analysis integrating the local presence of both imaging equipment and radiologists into a unified typology of imaging access and to evaluate its association with imaging utilization.

Materials and methods: Radiologists were identified in the June 2026 National Plan and Provider Enumeration System using six verified taxonomy codes and assigned to counties by practice ZIP code. Imaging infrastructure combined hospital presence, Medicare computed tomography or magnetic resonance imaging billing, and certified mammography facilities. Counties were classified into four groups based on local radiologist and imaging equipment presence: true imaging deserts (neither), equipment-only, radiologist-only, and fully served (both). Sensitivity definitions used diagnostic-only taxonomies, Medicare billing, and billing-volume thresholds. Medicare imaging utilization was compared across categories. Multivariable logistic regression modeled radiologist absence and true imaging desert status.

Results: A total of 1692/3144 (53.8%) counties had no documented local radiologist. A total of 568 counties were true imaging deserts (1.9% of residents), 1124 were equipment-only (7.6%), 19 were radiologist-only (0.1%), and 1433 were fully served (90.4%). Imaging utilization was lower in true imaging deserts than fully served counties (3989 vs. 4242 per 1000, P < 0.001); this difference held across varying equipment definitions. The no-radiologist share ranged 53.8%-63.3% across three workforce definitions. At the commuting-zone level, the prevalence of no-radiologist counties decreased to 16.8% and of true imaging desert counties to 1.7%. Smaller population and lower education predicted both county-level outcomes.

Conclusion: Local imaging access stratifies into four county types with measurable utilization differences. Equipment-only counties and true imaging deserts may warrant different policy responses.