scholarly journals Non-invasive imaging of the coronary arteries

2018 ◽  
Vol 40 (29) ◽  
pp. 2444-2454 ◽  
Author(s):  
Philip D Adamson ◽  
David E Newby

Abstract Non-invasive imaging of the coronary arteries is an enterprise in rapid development. From the research perspective, there is great demand for in vivo techniques that can reliably identify features of high-risk plaque that may offer insight into pathophysiological processes and act as surrogate indicators of response to therapeutic intervention. Meanwhile, there is clear clinical need for greater accuracy in diagnosis and prognostic stratification. Fortunately, ongoing technological improvements and emerging data from randomized clinical trials are helping make these elusive goals a reality. This review provides an update on the current status of non-invasive coronary imaging with computed tomography, magnetic resonance, and positron emission tomography with a focus on current clinical applications and future research directions.

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2348
Author(s):  
Leon Riehakainen ◽  
Chiara Cavallini ◽  
Paolo Armanetti ◽  
Daniele Panetta ◽  
Davide Caramella ◽  
...  

Non-invasive longitudinal imaging of osseointegration of bone implants is essential to ensure a comprehensive, physical and biochemical understanding of the processes related to a successful implant integration and its long-term clinical outcome. This study critically reviews the present imaging techniques that may play a role to assess the initial stability, bone quality and quantity, associated tissue remodelling dependent on implanted material, implantation site (surrounding tissues and placement depth), and biomarkers that may be targeted. An updated list of biodegradable implant materials that have been reported in the literature, from metal, polymer and ceramic categories, is provided with reference to the use of specific imaging modalities (computed tomography, positron emission tomography, ultrasound, photoacoustic and magnetic resonance imaging) suitable for longitudinal and non-invasive imaging in humans. The advantages and disadvantages of the single imaging modality are discussed with a special focus on preclinical imaging for biodegradable implant research. Indeed, the investigation of a new implant commonly requires histological examination, which is invasive and does not allow longitudinal studies, thus requiring a large number of animals for preclinical testing. For this reason, an update of the multimodal and multi-parametric imaging capabilities will be here presented with a specific focus on modern biomaterial research.


2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Martin Thunemann ◽  
Barbara F. Schörg ◽  
Susanne Feil ◽  
Yun Lin ◽  
Jakob Voelkl ◽  
...  

Non-invasive, non-destructive assay of energy-related metabolic activity of body tissues is the goal of several biophysical approaches, surface fluorometry of mitochondrial flavoprotein, positron emission tomography and 31 P n.m.r. Each has an appropriate specificity, time range, resolution and tissue damage potential. 31 P n.m.r. is the least invasive and at 72 MHz, with a 20 min averaging time and a 20 mm bore magnet, it affords in vivo assay of energy related compounds of tissues in small animals, such as fish skeletal muscle (loach) and heads of adult mouse and of newborn gerbils. In the transition from normoxia and nitrogen anoxia, decreases of the creatine phosphate : inorganic phosphate ratios from 3.9, 5.0, 2.7 in normoxia to 1.2, 0.04, 0.06 in anoxia occur in fish, mouse and gerbil respectively. The remarkable retention of significant ATP levels (80% of normoxic) in the new-born gerbil through 20 min of N 2 anoxia is clearly demonstrated. Evidence for the origin of much of the in vivo signal from the mouse brain is afforded by the fast freeze-trapping, excision of brain and assay by cryo-n.m.r. (Chance, B. et al . 1978 Proc. natn. Acad. Sci. U.S.A. 75, 4925-4929) at —12 °C, the lowest temperature at which tissue signals are observed.


2021 ◽  
pp. 0271678X2110477
Author(s):  
Laura Michiels ◽  
Nathalie Mertens ◽  
Liselot Thijs ◽  
Ahmed Radwan ◽  
Stefan Sunaert ◽  
...  

Functional alterations after ischemic stroke have been described with Magnetic Resonance Imaging (MRI) and perfusion Positron Emission Tomography (PET), but no data on in vivo synaptic changes exist. Recently, imaging of synaptic density became available by targeting synaptic vesicle protein 2 A, a protein ubiquitously expressed in all presynaptic nerve terminals. We hypothesized that in subacute ischemic stroke loss of synaptic density can be evaluated with 11C-UCB-J PET in the ischemic tissue and that alterations in synaptic density can be present in brain regions beyond the ischemic core. We recruited ischemic stroke patients to undergo 11C-UCB-J PET/MR imaging 21 ± 8 days after stroke onset to investigate regional 11C-UCB-J SUVR (standardized uptake value ratio). There was a decrease (but residual signal) of 11C-UCB-J SUVR within the lesion of 16 stroke patients compared to 40 healthy controls (ratiolesion/controls = 0.67 ± 0.28, p = 0.00023). Moreover, 11C-UCB-J SUVR was lower in the non-lesioned tissue of the affected hemisphere compared to the unaffected hemisphere (ΔSUVR = −0.17, p = 0.0035). The contralesional cerebellar hemisphere showed a lower 11C-UCB-J SUVR compared to the ipsilesional cerebellar hemisphere (ΔSUVR = −0.14, p = 0.0048). In 8 out of 16 patients, the asymmetry index suggested crossed cerebellar diaschisis. Future research is required to longitudinally study these changes in synaptic density and their association with outcome.


2018 ◽  
Vol 18 (2) ◽  
pp. 115-127 ◽  
Author(s):  
Elissa McCarthy ◽  
Joan M. Cook

Older adults have generally not been included in randomized clinical trials of psychotherapy for posttraumatic stress disorder (PTSD). Of the case reports and treatment outcome studies that have included those aged 55 and older, most did not include men with sexual abuse-related PTSD. This case report presents the successful application of Prolonged Exposure (PE) to a 58-year-old single, Caucasian noncombat U.S. Army veteran with severe, chronic PTSD related to several sexual assaults, including childhood sexual abuse. PE is a manualized, short-term, evidence-based psychotherapy for the treatment of PTSD which involves psychoeducation, breathing retraining, in vivo exposure, and imaginal exposure. PTSD and depressive symptoms demonstrated clinically meaningful improvement during the course of treatment. In addition, he experienced significant improvement in quality of life as well as meaning and purpose from baseline to posttreatment. Implications for clinically working with older men with untreated childhood sexual abuse-related PTSD later in life are presented. Future research directions are discussed.


1999 ◽  
Vol 58 (4) ◽  
pp. 861-870 ◽  
Author(s):  
A. Heerschap ◽  
C. Houtman ◽  
H. J. A. in 't Zandt ◽  
A. J. van den Bergh ◽  
B. Wieringa

31P magnetic resonance spectroscopy (MRS) offers a unique non-invasive window on energy metabolism in skeletal muscle, with possibilities for longitudinal studies and of obtaining important bioenergetic data continuously and with sufficient time resolution during muscle exercise. The present paper provides an introductory overview of the current status of in vivo31P MRS of skeletal muscle, focusing on human applications, but with some illustrative examples from studies on transgenic mice. Topics which are described in the present paper are the information content of the 31P magnetic resonance spectrum of skeletal muscle, some practical issues in the performance of this MRS methodology, related muscle biochemistry and the validity of interpreting results in terms of biochemical processes, the possibility of investigating reaction kinetics in vivo and some indications for fibre-type heterogeneity as seen in spectra obtained during exercise.


2019 ◽  
Vol 11 (10) ◽  
pp. 1327-1337
Author(s):  
Xin Chen

Nanomaterials (NMs) have wide applications in industrial and household areas, and possibilities of exposure to NMs are increasing, prompting considerable concerns about safety issues related to them. This paper describes the research landscape of nanotoxicity over the past ten years by adopting bibliometric methods. Annual, regional, and institutional distributions, as well as regional/institutional impact of literature on nanotoxicity were analyzed. Both quantitative and citation-based analyses were carried out to reveal the research hotspots. Results showed that cytotoxicity was the most concerned issue in the application of NMs, especially in imaging, diagnosis, and therapy. There were also a large number of studies on ecotoxicity, oxidative stress, apoptosis, genotoxicity, inflammation, and reproductive toxicity caused by NMs. NMs such as Ag, Au, graphene-based materials (GBMs), carbon nanotubes (CNTs), TiO2, SiO2, etc. were the most studied materials. Moreover, a growing number of both in vivo and in vitro studies involving NMs have been carried out in the past ten years. Mammalian models, such as mouse, human and rat, were the most studied models. A Sankey diagram between study types and experimental models showed that in vivo studies exceeded in vitro studies for some well-established animal models. Yet in-depth in vivo studies regarding interactions of NMs within human systems were still essential. With rapid development of nanotechnology, toxic and safety issues on NMs need to be addressed more specifically in future research.


2016 ◽  
Vol 23 (4) ◽  
pp. 496-504 ◽  
Author(s):  
Laura Airas ◽  
Eero Rissanen ◽  
Juha Rinne

Multiple sclerosis (MS) is a complex disease, where several processes can be selected as a target for positron emission topography (PET) imaging. Unlike magnetic resonance imaging (MRI), PET provides specific and quantitative information, and unlike neuropathology, it can be non-invasively applied to living patients, which enables longitudinal follow-up of the MS pathology. In the study of MS, PET can be useful for in vivo evaluation of specific pathological characteristics at various stages of the disease. Increased understanding of the progressive MS pathology will enhance the treatment options of this undertreated condition. The ultimate goal of developing and expanding PET in the study of MS is to have clinical non-invasive in vivo imaging biomarkers of neuroinflammation that will help to establish prognosis and accurately measure response to therapeutics. This topical review provides an overview of the promises and challenges of the use of PET in MS.


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