At the University of Michigan, researchers have validated a breakthrough imaging tool that could spare thousands of patients from one of medicine's most invasive diagnostic procedures. The new PET radiotracer, called 11C-Nevanimibe, can noninvasively identify overactive adrenal glands—offering a gentler alternative to adrenal vein sampling, the gold standard for diagnosing primary aldosteronism that requires threading catheters directly into tiny blood vessels near the kidneys.
Primary aldosteronism, also known as Conn's syndrome, is the largest known cause of curable secondary hypertension. The condition occurs when the adrenal glands overproduce aldosterone from cholesterol, artificially driving up blood pressure. Currently, the only way physicians can determine whether one or both glands are overactive—a distinction that determines whether surgery or lifelong medication is the answer—is through adrenal vein sampling, a procedure typically performed only at specialized medical centers and carrying real risks.
The first-in-human study, led by Benjamin Viglianti, MD, Ph.D., director of the Nuclear Medicine Division at University of Michigan, involved nine participants: six healthy controls and three patients with previously diagnosed overactive adrenal glands. Using the novel 11C-Nevanimibe tracer, researchers measured how much radioactive tracer accumulated in the adrenal glands compared to the liver, a standard reference organ in nuclear imaging.
The results were striking: in patients with adrenal pathology, the adrenal-to-liver uptake ratio averaged 1.2, compared to just 0.7 in healthy subjects—a clear and measurable distinction that could guide clinical decisions. Peter Scott, Ph.D., Paul L. Carson Legacy Professor of Radiology at the University of Michigan, explained the clinical stakes: "One overactive adrenal gland can be removed to cure the overproduction, but if the overproduction is in both glands, patients require lifetime medication management. By using a PET radiotracer that targets cholesterol metabolism in the adrenal glands, physicians can noninvasively identify overactive glands to guide clinical decision-making."
The validation was presented at the Society of Nuclear Medicine and Molecular Imaging 2026 Annual Meeting in Los Angeles this past May, building on years of preclinical research. Crucially, the human biodistribution of 11C-Nevanimibe closely mirrored preclinical animal studies, suggesting the tracer behaves as predicted in real patients—a critical milestone for translating laboratory discoveries into clinical tools.
Gina Kaup, a graduate student in medicinal chemistry at the University of Michigan who contributed to the work, noted the significance for underserved patients: "This work further expands molecular imaging to benefit a population of patients currently lacking in non-invasive accessible diagnostic techniques. Additional clinical studies are underway to study dosimetry and efficacy of this tracer."
For the thousands of people diagnosed with high blood pressure each year, some of whom unknowingly have primary aldosteronism, this tool could mean fewer invasive procedures and faster, more confident answers about which treatment path will actually cure their condition. Larger clinical trials are already underway to confirm that 11C-Nevanimibe can reliably replace adrenal vein sampling in routine practice—potentially transforming how physicians approach one of medicine's most challenging diagnostic dilemmas.