Comparison of BMIPP-SPECT/CT to 18FDG-PET/CT for Imaging Brown or Browning Fat in a Preclinical Model.

Obesity is a leading cause of preventable death and morbidity. To elucidate the mechanisms connecting metabolically active brown adipose tissue (BAT) and metabolic health may provide insights into methods of treatment for obesity-related conditions. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FDG-PET/CT) is traditionally used to image human BAT activity. However, the primary energy source of BAT is derived from intracellular fatty acids and not glucose. Beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) is a fatty acid analogue amenable to in vivo imaging by single photon emission computed tomography/CT (SPECT/CT) when radiolabeled with iodine isotopes. In this study, we compare the use of 18FDG-PET/CT and 125I-BMIPP-SPECT/CT for fat imaging to ascertain whether BMIPP is a more robust candidate for the non-invasive evaluation of metabolically active adipose depots. Interscapular BAT, inguinal white adipose tissue (iWAT), and gonadal white adipose tissue (gWAT) uptake of 18FDG and 125I-BMIPP was quantified in mice following treatment with the BAT-stimulating drug CL-316,243 or saline vehicle control. After CL-316,243 treatment, uptake of both radiotracers increased in BAT and iWAT. The standard uptake value (SUVmean) for 18FDG and 125I-BMIPP significantly correlated in these depots, although uptake of 125I-BMIPP in BAT and iWAT more closely mimicked the fold-change in metabolic rate as measured by an extracellular flux analyzer. Herein, we find that imaging BAT with the radioiodinated fatty acid analogue BMIPP yields more physiologically relevant data than 18FDG-PET/CT, and its conventional use may be a pivotal tool for evaluating BAT in both mice and humans.

Clinical Characteristics of 3 Patients Infected with COVID-19: Age, Interleukin 6 (IL-6), Lymphopenia, and Variations in Chest Computed Tomography (CT).

BACKGROUND COVID-19 has been identified as the cause of the large outbreak of pneumonia in patients in Wuhan with shared history of exposure to the Huanan seafood market; however, there is more to learn about this disease. Some experts report that the virus may have reduced toxicity during transmission, but others say that toxicity does not change during transmission. CASE REPORT In this case series, we report clinical and imaging characteristics of 3 patients (A, B, and C) infected with COVID-19. In an exposure-tracking epidemiological investigation, we found that it is possible that Patient A transmitted the infection to her treating physician, Patient B. Patient B then likely transmitted the infection to her family member, Patient C. From the chest CT studies and clinical characteristics, we postulate that the virulence did not decrease during human-to-human transmission. In previous studies, patients with the virus infection had changes in chest CT; however, we found that during the early stages of this disease, some patients (Patient C) may have normal chest CT scans and laboratory studies. Most importantly, we found that IL-6 levels were highest and lymphocyte count was lowest in those with more severe infection. CONCLUSIONS In this case series, we report the exposure relationship of the 3 patients and found that chest CT scans may not have any changes at the beginning of this disease. Lymphopenia and elevated levels of IL-6 can be found after infection.