Perceived Radiation Risks, Alzheimers Disease and Next-generation Imaging Approaches
This issue provides discussions about potential risks associated with diagnostic tests in pediatric patients, PET probes for imaging neuroinflammation and neurodegenerative diseases, as well as emerging hybrid imaging technologies such as PET/MRI.
Discussions about radiation risks associated with medical imaging are frequently based on emotions, and not on facts. We are increasingly faced with patients and their families who elect to not undergo critically important diagnostic studies because of the perception of risk. It is time for imaging experts to stand up against fears that are based on irrational perceptions rather than scientific facts.
Imaging of neuroinflammation and degenerative brain diseases might provide insight into the pathology of these disorders. Molecular imaging probes for imaging a variety of inflammatory neurological diseases have recently been introduced. One such probe, PK11195, binds to a protein that is expressed on the outer mitochondrial membrane of activated microglia and macrophages. Initial studies in Huntington’s disease have suggested that the degree of probe- binding might allow predictions of disease progression, while studies in Parkinson’s and Alzheimer’s patients provided less clear results. However, the study of inflammation as a cause or consequence of neurological diseases will be greatly aided by imaging approaches that could be used as biomarkers of disease progression and response to therapy.
At the same time, Amyvid, a PET probe that binds to beta-amyloid, has recently been approved for imaging amyloid plaque burden by the U.S. FDA. As any novel imaging probe, Amyvid will require careful clinical evaluations in large groups of patients. Comparisons with the much less expensive and well-established gold standard F-18 FDG-PET scan will be needed to determine additional benefits of this approach.
Highly specific PET probes have greatly benefitted from the availability of hybrid imaging devices such as PET/CT and PET/MRI. MRI provides the high soft-tissue contrast of MRI various options such as spectroscopy and functional information. PET/MRI thus offers unique research capabilities in cancer, neurological and cardiovascular diseases. The future will show whether PET/MRI will remain a research tool for academic institutions or whether it will gain widespread acceptance in the care of patients.
–Johannes Czernin, MD
Professor, Molecular & Medical Pharmacology Director, Nuclear Medicine Clinic, Positron Emission Tomography/Computed Tomography, David Geffen School of Medicine at UCLA, Los Angeles, Calif.
Discussions about radiation risks associated with medical imaging are frequently based on emotions, and not on facts. We are increasingly faced with patients and their families who elect to not undergo critically important diagnostic studies because of the perception of risk. It is time for imaging experts to stand up against fears that are based on irrational perceptions rather than scientific facts.
Imaging of neuroinflammation and degenerative brain diseases might provide insight into the pathology of these disorders. Molecular imaging probes for imaging a variety of inflammatory neurological diseases have recently been introduced. One such probe, PK11195, binds to a protein that is expressed on the outer mitochondrial membrane of activated microglia and macrophages. Initial studies in Huntington’s disease have suggested that the degree of probe- binding might allow predictions of disease progression, while studies in Parkinson’s and Alzheimer’s patients provided less clear results. However, the study of inflammation as a cause or consequence of neurological diseases will be greatly aided by imaging approaches that could be used as biomarkers of disease progression and response to therapy.
At the same time, Amyvid, a PET probe that binds to beta-amyloid, has recently been approved for imaging amyloid plaque burden by the U.S. FDA. As any novel imaging probe, Amyvid will require careful clinical evaluations in large groups of patients. Comparisons with the much less expensive and well-established gold standard F-18 FDG-PET scan will be needed to determine additional benefits of this approach.
Highly specific PET probes have greatly benefitted from the availability of hybrid imaging devices such as PET/CT and PET/MRI. MRI provides the high soft-tissue contrast of MRI various options such as spectroscopy and functional information. PET/MRI thus offers unique research capabilities in cancer, neurological and cardiovascular diseases. The future will show whether PET/MRI will remain a research tool for academic institutions or whether it will gain widespread acceptance in the care of patients.
–Johannes Czernin, MD
Professor, Molecular & Medical Pharmacology Director, Nuclear Medicine Clinic, Positron Emission Tomography/Computed Tomography, David Geffen School of Medicine at UCLA, Los Angeles, Calif.