ABSTRACT
Introduction: We aimed to characterize the clinical impact of amyloid PET (APET) in a veteran population with cognitive decline by comparing differences in management between those who did and did not have an APET. Methods: This was a retrospective observational study. Poisson regressions and logistic regression were used for comparisons. Results: Out of 565 veterans, 197 underwent APET; positivity rate was 36.55%. Having an APET was associated with longer follow-up, and increased diagnostic variability; it was not associated with number of additional studies, cholinesterase inhibitors prescription, or referrals to research. A positive APET was associated with less diagnostic variability, fewer additional tests, greater cholinesterase inhibitor prescriptions, and more research referrals. Discussion: In a medically complex, real-world population, APET yielded lower positivity rates and was not associated with classical clinical utility variables when comparing patients with and without an APET. APET may be used more to "rule out" rather than to confirm Alzheimer's disease. Highlights: Amyloid PET was associated with longer follow-up, and higher diagnostic variability.No association was seen with cholinesterase inhibitors prescription, or referrals to research.In complex patients, expected amyloid PET positivity rates are lower than previously described.Amyloid PETs were used to "rule out" AD than to confirm the diagnosis of AD.
ABSTRACT
Introduction: This study assessed the ordering of amyloid positron emission tomography (PET) scans in a Veterans Affairs (VA) memory disorders clinic as part of routine clinical care, with possible implications for the extent to which ordering may occur outside of the VA in the future if covered by insurance. Methods: Clinical features predictive of ordering amyloid PET scans were retrospectively assessed; the percentage of patients who met appropriate use criteria were evaluated. Results: Among 565 veterans, 34.9% of received an amyloid PET scan and 98.0% of these were consistent with appropriate use criteria. Patients with a PET were younger and more likely to have an initial diagnosis of Alzheimer's disease (AD). Of patients without an amyloid PET scan ordered, 64.4% would have met appropriate use criteria for amyloid PET. Discussion: The majority of scans ordered were consistent with appropriate use criteria and more patients were eligible than received a scan. The current study's findings that approximately one-third of patients in a memory disorders clinic received an amyloid PET scan has implications for memory disorders clinics inside and outside of the US Veterans Health Administration.
ABSTRACT
This report presents our experience with Transcranial Doppler (TCD) ultrasonography and Single Photon Emission Computed Tomography (SPECT) in the assessment of patients with aneurysmal subarachnoid haemorrhage (SAH). It was designed to evaluate clinical vasospasm with both TCD and SPECT and determine their diagnostic value. Twenty-eight consecutive patients were examined with both TCD and SPECT, performed within 24 hours of each other. They had a total of 45 TCDs and 46 SPECT scans. Eight patients (29%) developed clinical vasospasm, noted from day 2 to day 11 post subarachnoid haemorrhage; these patients underwent TCDs and SPECT scans when the diagnosis of vasospasm was made. Twenty patients (71%) did not demonstrate clinical vasospasm throughout their hospital stay and underwent TCDs and SPECT scans within the first 2 weeks of their SAH, mostly between day 2 and day 10, the period of greatest risk for vasospasm. TCD and SPECT sensitivity for clinical vasospasm was 100% and 50% respectively, their specificity was only 20% and 60%. TCD sensitivity for symptomatic vasospasm was found to be excellent, whereas SPECT was not found to be as useful. We conclude that TCD is the preferred method in the evaluation of patients with subarachnoid haemorrhage.
