Optical molecular imaging is a powerful imaging method, which can in vivo monitor physiological and pathobiological processes at the cellular and molecular levels, as opposed to the anatomical level, bridging the gap between imaging and biological processes. Because of its relevance in cardiovascular diseases research, the use of this technology for imaging of cardiovascular diseases advances at a rapid pace in the past decade. This review summarizes the optical molecular imaging methods for imaging the specific targets in cardiovascular diseases, which hold promise for in vivo applications in cardiovascular diseases research. Collectively, in vivo optical molecular imaging may be highly suitable for discriminating targets that play key roles in the occurrence and development of the instable atherosclerosis, thrombogenesis, myocardial infarction, myocardial apoptosis, angiogenesis, as well as in cardiac cell transplantation. Keywords: Bioluminescent imaging, cardiovascular diseases, fluorescence molecular tomography, near-infrared fluorescence imaging, optical imaging.
Cardiovascular diseases are generally synonymous with atherosclerosis and cardiac events from occluded vessels, although a multitude of other clinically significant diseases with occluded arteries exist. They often revolve around inflammatory processes, locally within or around the vessels as well as systemic, and they may result in significant morbidity and mortality. The systemic inflammatory component may manifest itself throughout the vasculature, but structural changes are often limited, which hamper the use of conventional and localized structural imaging. On the other hand, sensitive whole-body molecular imaging offers a unique diagnostic approach to these disorders. This is particularly true for positron emission tomography/computed tomography (PET/CT) with 18F-flourodeoxyglucose (FDG) which in recent years has become an established tool not only in cancer but also increasingly in infectious and inflammatory diseases. This review outlines current applications of FDG PET/CT in the most common vascular infectious and inflammatory diseases, i.e. vascular graft infections, vasculitis, and deep venous thrombosis (DVT). Keywords: PET, PET/CT, FDG, vascular disease, vascular graft infection, vasculitis, venous thromboembolism.
The use of whole-body imaging with 18F-fluorodeoxyglucose positron emission tomography/ computed tomography (FDG-PET/CT) is increasing in systemic infectious diseases, including fever of unknown origin (FUO), bacteraemia of unknown origin (BUO), and central nervous system infections, since the primary aim is to guide the clinicians towards potential sites of origin for further exploration, and a high sensitivity whole-body assessment is therefore pivotal. The literature on these subjects remains relatively sparse, but the available data and the widespread use in daily clinical practice seem justified in FUO and BUO, while results on CNS infections with systemic components are more equivocal. However, more systematic, well-designed prospective studies in defined patient populations are needed to clarify the controversies, including indications and cost effectiveness, scan parameters, and quantification. Keywords: PET, PET/CT, FDG, infection, fever of unkown origin, bacteraemia, CNS.
Cocaine has been known to inhibit dopaminergic and serotonergic systems. Here, we aimed to study the addictive effects of cocaine on both systems of rats after chronic treatments. Rats were treated with vehicle or cocaine for four months, and the changes of behavior and expressions and activity of dopaminergic and serotonergic systems were assessed. Locomotion was used to estimate the animal behavior. The neuronal imaging of dopamine D2 receptor (D2R) with [11C]raclo- [11C]raclopride/microPET and serotonin transporter (SERT) with [123I]-2-((2-((dimethylamino) methyl) phenyl) thio)-5- iodophenylamine ([123I]ADAM)/gamma scintigraphy was performed for determining the specific striatum/midbrain binding ratios. Animal Magnetic Resonance Imaging (MRI) and immunohistochemistry (IHC) were applied to assess the anatomical changes in the rat brains. The activated locomotion was found for the first ten weeks, and gradually recovered to the baseline. Brain D2R imaging (i.e., [11C]raclopride/microPET) showed the decreased ratio of striatum/midbrain during the study and two weeks post the withdrawal of cocaine treatments. Brain SERT imaging (i.e., [123I]ADAM/gamma scintigraphy) was also found similar to the declined ratio of midbrain/cerebellum. However, animal MRI did not find brain hemorrhage and edema. Notably, the results obtained from IHC showed serious neuronal damage with decreased Tyrosine Hydroxylase (TH)-positive and increased glial fibrillary acidic protein (GFAP)-positive expressions in the critical brain regions. These results demonstrate that the predominant effect of chronic cocaine treatments on the dopaminergic system is more severe than on the serotonergic system as evaluated with the behavioral tolerance, D2R impairment, and dopamine neuron deficit. Keywords: [11C]raclopride, [123I]ADAM, dopamine D2 receptor, glial fibrillary acidic protein, serotonin transporter, tyrosine hydroxylase.
Background: Evaluation of focal liver injury is an important obstacle facing precise liver surgery. We investigated for a correlation between the average ADC of the whole liver and serum liver function tests, and also sought to determine a diagnostic ADC threshold for diagnosing liver injury. Materials and Methods: Diffusion weighted imaging (DWI) and liver function tests were performed on 24 patients with common bile duct (CBD) stones and 20 normal control volunteers. Statistical analyses including Spearman correlation analysis and ROC analysis were performed to determine the ability for the apparent diffusion coefficient (ADC) to predict focal liver injury. Results: The average ADC value of control and CBD stones groups were 1378±93mm2/s and 1084±190mm2/s. The ADC value significantly correlated with serum liver function tests including total bilirubin, direct bilirubin, γ- glutamyltransferase, and alkaline phosphatase measurements (r=-0.573,-0.528,-0.549, and -0.595, P < 0.001). ROC analysis of ADC as a predictor for focal abnormal liver function was performed using a reference standard of serum liver functional tests (1990 Council for International Organizations of Medical Sciences) and demonstrated an area under the curve (AUC) of 0.946. Using an ADC of 1249mm2/s as the threshold value, sensitivity was 79.2% (95%CI 57.8-92.9%) and specificity was 100% (95%CI 83.2-100.0%). Conclusion: Noninvasive diffusion weighted imaging is able to identify focal hepatocellular injury from biliary obstruction. Keywords: Apparent diffusion coefficient, common bile duct stones, diffusion weighted imaging, focal liver injury, functional imaging, magnetic resonance imaging, ROC, sensitivity and specificity.
