A Duke University study found that access to SPECT/CT imaging is highly unequal across the U.S., with facilities concentrated in coastal and urban areas while many communities receive no meaningful access. Racial composition and population size are significant drivers of these disparities, requiring strategic expansion of advanced diagnostic services to prioritize equity alongside innovation.
- 1,661 SPECT/CT facilities were identified nationally, with highly unequal distribution (Gini coefficient = 0.327)
- Coastal and urban areas have concentrated facility density, while many regions receive no meaningful access to SPECT/CT imaging
- Racial composition and population size are significant drivers of disparities, while income and sex are not predictive factors
- California, Texas, and Florida have the most facilities in absolute terms, but smaller states like South Dakota and Vermont rank highest per 100,000 residents
- Recommended strategies include mobile imaging units, strengthened referral networks, and reimbursement model alignment to improve access in underserved regions
Patient access to SPECT/CT imaging across the U.S. is marked by stark geographic and racial disparities, according to a study published September 1 in the Journal of the American College of Radiology.
A group from Duke University School of Medicine examined the national distribution of SPECT/CT facilities and quantified disparities in spatial access across demographic groups, with findings intended to inform strategies for improving access, noted lead authors Andreas Seas, PhD, and Felix Toussaint, MD, and colleagues.
"Incorporating geospatial analyses into healthcare planning can help identify underserved areas and guide equitable placement of advanced diagnostic services, provided such analyses are paired with economic feasibility evaluation," the group wrote.
Geographic disparities in advanced imaging, such as MRI, CT, and PET, are well documented, but the geographic and demographic accessibility of SPECT/CT, a hybrid imaging technology used across oncology, cardiology, and neurology, have not been rigorously characterized nationally, the authors wrote.
To bridge the gap, the researchers identified 1,661 SPECT/CT facilities nationally using the American College of Radiology (ACR) Accredited Facilities Database. They applied a spatial access modeling approach to estimate proximity-weighted access for communities across the contiguous U.S. The team then measured national inequality in access and examined whether racial composition, population size, income, and sex predicted local disparities.
According to the results, spatial access was highly unequal (Gini coefficient = 0.327; Theil index = 0.205), with facility density concentrated in coastal and urban areas and with many areas receiving no meaningful access. At the state level, California, Texas, and Florida had the highest number of facilities in absolute terms, while per capita availability varied significantly, with smaller states such as South Dakota and Vermont ranking highest per 100,000 residents.
Further, racial composition and population size were significant drivers of between-group disparity, while income and sex were not. Communities with lower proportions of white residents and those in high-population areas showed the greatest within-group inequality, and the magnitude of the racial access gap varied markedly across regions, the researchers reported.
"For health systems and policymakers, these findings argue for strategic expansion of advanced diagnostic services in a way that prioritizes equity alongside innovation and economic feasibility," the researchers wrote.
Ultimately, barriers to advanced imaging access carry clinical consequences, as late-presenting disease often requires more intensive treatment, they noted. Potential strategies for closing access gaps include deploying mobile imaging units, strengthening referral networks across facilities, and aligning reimbursement models to encourage appropriate utilization in underserved regions, they suggested.
"Future studies comparing SPECT/CT access to that of alternative imaging modalities such as MRI, CT, or PET using a common framework would enable more direct interpretation of the degree of relative disparity," the group concluded.
The full study is available here.
