Obesity has been shown to affect cardiovascular function. Heart rate variability (HRV) has been an accepted method of measuring cardiovascular autonomic function. The aim of the study is to evaluate the impact of obesity on HRV using Poincaré plot (POP) analysis. A finding of sympathovagal imbalance in pre-obese adults in respiratory sinus arrhythmia (RSA) could provide important diagnostic inf...

Introduction The blood-brain barrier (BBB) plays a crucial role in protecting the brain from the entry of various neurotoxic or neuroactive agents. Impaired BBB function has been implicated in a variety of diseases including multiple sclerosis and traumatic brain injury for both pathogenesis and disease progression. Therefore, non-invasive in vivo measurement of BBB permeability is of importanc...

We recently developed a dynamic multi-bed PET data acquisition framework to translate the quantitative benefits of Patlak voxel-wise analysis to the domain of routine clinical whole-body (WB) imaging. The standard Patlak (sPatlak) linear graphical analysis assumes irreversible PET tracer uptake, ignoring the effect of FDG dephosphorylation, which has been suggested by a number of PET studies. I...

[11C]CURB is a novel irreversible radioligand for imaging fatty acid amide hydrolase in the human brain. In the present work, we validate an algorithm for generating parametric map images of [11C]CURB acquired with a high resolution research tomograph (HRRT) scanner. This algorithm applies the basis function method on an irreversible two-tissue compartment model (k4 = 0) with arterial input fun...

Cerebral infarct due to embolic stroke without recanalization was examined by cerebral blood flow (CBF) SPECT in the early acute stage, and the possibility of predicting the size it will reach in the later stages was evaluated. Twenty patients (67 +/- 13 years) were examined by CBF SPECT with 99mTc-ECD 4.5 +/- 3.1 hours after the onset of cardiogenic cerebral embolism. The ratio of the anteropo...

To evaluate myocardial blood flow (MBF) and cardiac function with a single dose of NH3, electrocardiographically (ECG) gated PET acquisition was performed after a dynamic PET scan was obtained. Gated blood-pool (GBP) imaging with C15O PET was also performed to compare the left ventricular ejection fraction (LVEF) obtained using the 2 methods. Methods: Six healthy volunteers and 34 patients with...

BACKGROUND AND PURPOSE A previous study demonstrated the need to use delayed acquisition rather than first-pass data for accurate blood-brain barrier permeability surface product (BBBP) calculation from perfusion CT (PCT) according to the Patlak model, but the optimal duration of the delayed acquisition has not been established. Our goal was to determine the optimal duration of the delayed PCT ...

UNLABELLED Quantitative studies of bone using (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) have a potentially valuable role in investigating the treatment of patients with metabolic bone disease. In this study we compared 3 different methods of measuring whole-skeleton (99m)Tc-MDP plasma clearance (K(bone)) in 12 osteoporotic postmenopausal women (mean age, 67.3 y) before participation in a cl...

SUMMARY Hemorrhagic transformation is a serious potential complication of ischemic stroke with damage to the BBB as one of the contributing mechanisms. BBB permeability measurements extracted from PCT by using the Patlak model can provide a valuable assessment of the extent of BBB damage. Unfortunately, Patlak assumptions require extended PCT acquisition, increasing the risk of motion artifacts...