Does the etiology of cardiac amyloidosis determine the myocardial uptake of [18F]-NaF PET/CT?

Objectives: Elevated blood pressure from cocaine can increase left ventricular (LV) metabolic activity, leading to structural changes such as hypertrophy. We aimed to assess the association between blood pressure and LV myocardial uptake of FDG, hypothesizing that HIV individuals with raised blood pressure will have higher FDG uptake. Methods: University of Pennsylvania enrolled patients with HIV on antiretroviral therapy with viral load <200 copy/ml. Cocaine usage in moderate to high amounts (cocaine disease score≥5) was subsequently documented. Full body PET scans were acquired 120 minutes post-injection of 18F-FDG(15 mCi) with low-dose CT scans for attenuation correction. Patients with imaging artifacts were excluded from the analysis. Regions of interest were drawn on axial slices using computer software (OsirixMD, v9.0.02) around LV myocardium. Average standard uptake value means (aSUVmean) were calculated for each patient. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were obtained prior to imaging; mean arterial pressure (MAP) was subsequently calculated. Linear regressions and Mann-Whitney U tests were employed for statistical analysis. Results: aSUVmean was higher in HIV patients with cocaine use (U(Ncocaine = 11, Nno cocaine=11) = 93, p=0.0336). In patients with cocaine use, there was a positive correlation between blood pressure and aSUVmean (SBP: r=0.70, p=0.0164; DBP: r=0.69, p=0.0185; MAP: r=0.72, p=0.0120). No significant correlations were found in HIV patients without cocaine use (SBP: r=0.03, p=0.9239; DBP: r=-0.50, p=0.1153; MAP: r=-0.32, p=0.3345). Conclusions: LV myocardial metabolism was more strongly positively correlated with blood pressure in HIV patients using cocaine compared to HIV patients without cocaine. These data suggest FDG-PET/CT can be used to monitor LV metabolic activity and allow for timely assessment of structural changes caused by cocaine use and hypertension.

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PET/CT Imaging and Physiology of Mice on High Protein Diet

International Journal of Molecular Sciences ◽

10.3390/ijms22063236 ◽

2021 ◽

Vol 22 (6) ◽

pp. 3236

Author(s):

Jürgen W. A. Sijbesma ◽

Aren van Waarde ◽

Lars Stegger ◽

Rudi A. J. O. Dierckx ◽

Hendrikus H. Boersma ◽

...

Keyword(s):

Body Weight ◽

Body Fat ◽

High Protein ◽

Myocardial Uptake ◽

Fat Percentage ◽

Fdg Uptake ◽

Pet Ct ◽

18F Fdg ◽

The Impact

Background: High protein (HP) diets have been proposed to reduce body weight in humans. The diets are known to alter energy metabolism, which can affect the quality of [18F]FDG PET heart images. In this preclinical study, we therefore explore the impact of a prolonged HP diet on myocardial [18F]FDG uptake. Methods: C57BL/6J (Black six (Bl6)) and apolipoprotein E-deficient (apoE−/−) mice were fed chow, a HP diet, or a low protein (LP) diet for 12 weeks. At baseline and after treatment, the animals were injected with 33.0 MBq of [18F]FDG and a 30 min PET/CT scan was made. Myocardial volume and [18F]FDG uptake were quantified using PET and the % of body fat was calculated from CT. Results: Myocardial [18F]FDG uptake was similar for all diets at the follow-up scan but an increase between baseline and follow-up scans was noticed in the LP groups. Myocardial volume was significantly smaller in the C57BL HP group compared to the other Bl6 groups. Body weight increased less in the two HP groups compared to the chow and LP groups. Body fat percentage was significantly higher in the LP groups. This effect was stronger in C57BL mice (28.7%) compared to apoE−/− mice (15.1%). Conclusions: Myocardial uptake of [18F]FDG in mice is not affected by increased protein intake but [18F]FDG uptake increases when the amount of protein is lowered. A lower body weight and percentage of body fat were noticed when applying a HP diet.

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