PET diagnostics in Alzheimer's disease: from 0.7% to a new standard

The Alzheimer's Association® recently unveiled a striking study on the real-world use of diagnostic tests for Alzheimer's disease (AD). What stood out to me immediately was one number: Positron Emission Tomography (PET), despite its well-documented ability to increase diagnostic accuracy and enable early detection of AD, represented a tiny fraction of all diagnostic testing procedures — just 0.7%. When I first read that figure, I had to pause. How could the most powerful confirmatory tool available account for less than one percent of tests performed?

The explanation, unfortunately, is painfully familiar: money. The out-of-pocket expense to patients, or the lack of reimbursement from insurers, was likely the main reason for such low uptake. Prior to October 2023, the Centers for Medicare & Medicaid Services (CMS) had limited reimbursements of amyloid-beta (Aβ) PET scans to patients enrolled in an authorized clinical trial. On top of that, Medicare beneficiaries were restricted to a single reimbursed Aβ PET scan per lifetime — a limitation that made little clinical sense given how neurodegenerative diseases progress over time. The result was a situation where the gold-standard diagnostic tool was effectively out of reach for the vast majority of patients.

But the landscape is changing, and I am genuinely optimistic about the direction we are heading. CMS has since lifted the clinical trial requirement and the one-scan limit. More importantly, with the advent of disease-modifying therapies (DMTs) for Alzheimer's disease, the use of PET tests is expected to increase substantially, because these treatments require confirmation of the presence of Aβ pathology before they can be initiated. Now that DMTs are available and reimbursement for the gold-standard confirmatory test is in place, we have the scientific and regulatory framework to actually deliver early, accurate diagnosis to patients who need it. As the evidence clearly shows, DMTs are more effective when administered in the early stages of the disease — which makes timely PET imaging not just useful, but essential.

Yet getting from 0.7% to a meaningful level of PET adoption requires more than policy changes. It requires substantial improvements in the accessibility and scalability of PET technology itself. That is exactly the mission I have dedicated myself to at PraanaTech. We have developed outstanding PET detector technology and designed imaging systems that bring better diagnostic performance hand in hand with accessibility — making it possible to perform high-quality amyloid PET not just at major academic centers, but in the communities where patients actually live. Early diagnosis for everyone, everywhere: that is not just a slogan for us. It is the engineering challenge we wake up to solve every day.