Hospital Concentration and Payer-Based Patterns in Inpatient Neuro MRI Utilization: A New York State Analysis, 2019–2023

Purpose: Advanced neuroimaging is central to inpatient neurologic care, yet statewide patterns of inpatient neuro MRI utilization by payer and hospital structure remain poorly characterized. We analyzed payer distribution, care pathways, diagnosis mix, and hospital-level concentration of inpatient neuro MRI encounters across New York State.

Methods/Materials: We conducted a retrospective analysis of adult inpatient hospitalizations involving neuro MRI using the New York Statewide Planning and Research Cooperative System (SPARCS) database from 2019–2023. MRI encounters were identified using Clinical Classifications Software Refined procedure descriptions. Primary payer was categorized as Medicare, Medicaid, Commercial, or Other. Analyses assessed payer mix, temporal trends, emergency department (ED)-associated utilization, diagnosis distribution, and hospital-level concentration.

Results: A total of 7,079 inpatient neuro MRI encounters were identified. Medicare accounted for 3,497 (49.4%) encounters, followed by Medicaid (1,917; 27.1%), Commercial insurance (1,345; 19.0%), and Other payers (320; 4.5%). From 2019 to 2023, the proportion of Medicaid-associated encounters increased from 23.4% to 29.2%, while Medicare declined from 51.9% to 47.4%. Overall, 62.3% of encounters were ED-associated, with the highest ED utilization observed among Medicaid and Medicare patients. The most common indications included cerebral infarction (49.9%), transient cerebral ischemia (11.7%), epilepsy or convulsions (10.0%), headache-related conditions (4.9%), and acute hemorrhagic cerebrovascular disease (4.4%). Neuro MRI utilization was highly concentrated: the top 10 hospitals accounted for 57.9% of encounters statewide despite participation from more than 130 hospitals. These high-volume centers largely serve socioeconomically disadvantaged populations, reflecting the role of safety-net and tertiary referral hospitals (Figure 1).

Conclusions: Inpatient neuro MRI utilization in New York State shows payer-based differences in care pathways and marked hospital-level concentration. These findings emphasize structural factors influencing access to advanced inpatient neuroimaging and may inform resource allocation across health systems.