PET imaging of 18F-florbetapir in cognitively impaired individuals: Lack of activity within the cerebellar cortex.

Ten individuals suspected of having possible Alzheimer disease underwent PET imaging using 18F-Flubetapir. Only one of ten individuals had a pattern typical for normal elderly control subjects with 9 of the 10 showing a Alzheimer type pattern for the cerebral cortex yet all 10 subjects had uniformly low to absent tracer localization to the cerebellar cortex; significantly high tracer activity was noted within the subcortical white matter of the cerebellum in a symmetric manner in all cases. In consideration of studies that have shown amyloid deposits within the cerebellar cortex in 90% of pathologically proven cases of Alzheimer's disease, these findings raise questions about the actual clinical value of florbetapir PET imaging in evaluating cerebellar involvement and raises questions whether PET imaging of this tracer accurately portrays patterns of amyloid deposition, as there is rapid hepatic metabolism of the parent compound after intravenous injection.

Systemic Immune Response to Vaccination on FDG-PET/CT.

A patient with newly diagnosed right lung cancer had transient F-fluorodeoxyglucose (FDG)-avid left axillary lymph nodes and intense splenic FDG uptake on positron emission tomography (PET)/computed tomography (CT). History revealed that the patient received a left-sided influenza vaccine 2-3 days before the examination. Although inflammatory FDG uptake in ipsilateral axillary nodes is reported, to our knowledge, this is the first report of visualization of the systemic immune response in the spleen related to the influenza vaccination on FDG-PET/CT.

Accurate detection of metabolically active "brown" and "white" adipose tissues with computed tomography.

Background: Adipose tissues (AT) are highly metabolically active complex endocrine organs and are classified into white (WAT) and brown AT (BAT) with proinflammatory and anti-inflammatory characteristics. The current study investigated the accuracy of computed tomography (CT) to quantitatively detect BAT and WAT based on Hounsfield unit (HU) threshold compared to standardized uptake values (SUVs) of corresponding AT with the use of positron emission tomography (PET).

Methods: One hundred twenty-four patients who underwent whole-body (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT were studied.

Sirolimus-induced interstitial pneumonitis in a renal transplant patient.

We report interstitial pneumonitis caused by sirolimus (Rapamune, an immunosuppressive agent) in a renal transplant patient. This rare manifestation was recently recognized as a troublesome adverse effect of sirolimus in many solid-organ transplant recipients, the majority of whom are kidney transplant recipients. While on sirolimus our patient developed cough, fever, and patchy infiltrates, which failed to respond to multiple courses of antibiotic therapy.