Regional changes with global brain hypometabolism indicates a physiological triage phenomenon and can explain shared pathophysiological events in Alzheimer's & small vessel diseases and delirium.

While reduced global brain metabolism is known in aging, Alzheimer's disease (AD), small vessel disease (SVD) and delirium, explanation of regional brain metabolic (rBM) changes is a challenge. We hypothesized that this may be explained by "triage phenomenon", to preserve metabolic supply to vital brain areas. We studied changes in rBM in 69 patients with at least 5% decline in global brain metabolism during active lymphoma.

Utility of metabolic heterogeneity factor in differentiating malignant versus benign parotid uptake on F FDG PET-CT.

Differentiation of benign and malignant parotid uptake on Fluorine 18 Fluro-Deoxy-Glucose Positron Emission Tomography-Computed Tomography (F FDG PET-CT) is of paramount importance due to the poor prognosis of the later but usual quantitative measures such as standardized uptake value (SUV) are not reliable for this purpose. Metabolic heterogeneity, being a characteristic of malignant tumors, would potentially be able to make this distinction. In this study, seventy-one FDG-avid parotid lesions were retrospectively separated histologically into benign and malignant groups.

Prostate-Specific Membrane Antigen Positron Emission Tomography-Computed Tomography for Prostate Cancer: Distribution of Disease and Implications for Radiation Therapy Planning.

Purpose: To explore the prostate-specific membrane antigen (PSMA)-avid distribution of prostate cancer (PC) on positron emission tomography (PET), both at the time of initial diagnosis and at the time of relapse after definitive local treatment.

Methods And Materials: A total of 179 PSMA PET scans in patients with nil or ≤3 lesions on conventional imaging were retrospectively categorized into 3 subgroups: group A, high-risk PC with no prior definitive therapy (n=34); group B, prior prostatectomy (n=75); and group C, prior radiation therapy (n=70). The numbers and locations of the PSMA-avid lesions were mapped.

68Ga-PSMA Uptake in Combined Hepatocellular Cholangiocarcinoma With Skeletal Metastases.

Ga-PSMA PET is a rapidly evolving imaging modality for whole-body staging of prostate cancer. We report a case of a 70-year-old man with mildly elevated prostate-specific antigen (8.1 μg/L) and clinical suspicion of prostate cancer (osteoblastic metastases on radionuclide bone scan) who was referred for Ga-PSMA PET/CT for primary staging.

Radionuclide bone scan SPECT-CT: lowering the dose of CT significantly reduces radiation dose without impacting CT image quality.

The CT component of SPECT-CT is required for attenuation correction and anatomical localization of the uptake on SPECT but there is no guideline about the optimal CT acquisition parameters. In our department, a standard CT acquisition protocol was changed in 2013 to give lower radiation dose to the patient. In this study, we retrospectively compared the effects on patient dose as well as the CT image quality with current versus older CT protocols.

Immunotherapy-induced sarcoidosis in patients with melanoma treated with PD-1 checkpoint inhibitors: Case series and immunophenotypic analysis.

Aim: Sarcoidosis is a multisystem granulomatous disease. This condition has a documented association with the diagnosis of melanoma and can be induced in melanoma patients receiving anti-neoplastic therapy. We evaluated a case series of melanoma patients who developed immunotherapy-induced sarcoidosis.