Anatomical assessment of intrathoracic cardiovascular structures using fast spin-echo double inversion recovery and steady-state free precession magnetic resonance imaging in a normal cat.

In human medicine, non-contrast cardiac magnetic resonance imaging (CMRI) is routinely used to assess the cardiovascular system. In this study, using non-contrast CMRI, we provide a thorough description of the normal appearance of the intrathoracic cardiovascular structures in one healthy cat using a magnet operating at a field of 1.5-Tesla. The CMRI protocol was based on the use of fast spin-echo double inversion recovery and steady-state free precession pulse sequences in oblique short-axis, vertical long-axis, and horizontal long-axis imaging planes. After imaging the feline heart, four cadaver cats injected with latex substance into their arterial and venous systems were sectioned to facilitate interpretation of the intrathoracic cardiovascular structures to the corresponding CMRI. The fast spin-echo double inversion recovery images showed the best evaluation of gross intrathoracic anatomy, giving excellent contrast of the myocardium and vessels walls as they appeared with intermediate signal intensity compared to the lumen that appeared with low signal intensity. By contrast, steady-state free precession images showed details of the heart cavities and vascular lumen due to the high signal intensity of fast-flowing blood. The results of this study provide some anatomic detail for the heart and associated vessels as seen by non-contrast CMRI in the domestic cat.

INVESTIGATION INTO CARDIOVASCULAR ASSESSMENT OF CAPTIVE ADULT SCARLET IBIS (EUDOCIMUS RUBER).

Cardiovascular lesions are commonly diagnosed postmortem in scarlet ibis (Eudocimus ruber), but antemortem diagnosis is rare. The aim of this study was to evaluate the cardiovascular health of a zoo population (n = 44) of apparently healthy, adult, scarlet ibis. A cross-sectional study design was employed whereby each animal was manually restrained for physical examination, phlebotomy, and echocardiographic examination performed with a 12-MHz transducer and a ventromedial approach, and observed intervals were calculated for 12 parameters. Seven individuals from the study population had high left-sided mid-ventricular velocities (2.59-5.89 m/sec) compared with values in other species. Follow-up examination suggested that these mid-ventricular obstructive lesions were dynamic and transient in nature rather than caused by fixed lesions within the outflow tract and may therefore be associated with stress. Conscious echocardiography proved to be feasible, although, unsurprisingly, the stress response in nonhabituated birds appeared to increase blood flow velocities. Handling protocols likely have a significant effect on echocardiographic parameters and should be taken into consideration when interpreting findings. Serum cholesterol concentrations were generally high (7.4-13.0 mmol/L), and further work is required to investigate the relationship between circulating cholesterol and the development of atherosclerosis in scarlet ibis. Serum cardiac troponin I concentrations were measured, and four animals were identified with suspected elevated levels, likely indicative of myocardial damage.

Computational medical imaging and hemodynamics framework for functional analysis and assessment of cardiovascular structures.

Cardiac dysfunction constitutes common cardiovascular health issues in the society, and has been an investigation topic of strong focus by researchers in the medical imaging community. Diagnostic modalities based on echocardiography, magnetic resonance imaging, chest radiography and computed tomography are common techniques that provide cardiovascular structural information to diagnose heart defects. However, functional information of cardiovascular flow, which can in fact be used to support the diagnosis of many cardiovascular diseases with a myriad of hemodynamics performance indicators, remains unexplored to its full potential. Some of these indicators constitute important cardiac functional parameters affecting the cardiovascular abnormalities. With the advancement of computer technology that facilitates high speed computational fluid dynamics, the realization of a support diagnostic platform of hemodynamics quantification and analysis can be achieved. This article reviews the state-of-the-art medical imaging and high fidelity multi-physics computational analyses that together enable reconstruction of cardiovascular structures and hemodynamic flow patterns within them, such as of the left ventricle (LV) and carotid bifurcations. The combined medical imaging and hemodynamic analysis enables us to study the mechanisms of cardiovascular disease-causing dysfunctions, such as how (1) cardiomyopathy causes left ventricular remodeling and loss of contractility leading to heart failure, and (2) modeling of LV construction and simulation of intra-LV hemodynamics can enable us to determine the optimum procedure of surgical ventriculation to restore its contractility and health This combined medical imaging and hemodynamics framework can potentially extend medical knowledge of cardiovascular defects and associated hemodynamic behavior and their surgical restoration, by means of an integrated medical image diagnostics and hemodynamic performance analysis framework.

Applications of three-dimensional printing technology in the cardiovascular field.

Three-dimensional (3-D) printing technology has rapidly developed in the last few decades. Meanwhile, the application of this technology has reached beyond the engineering field and expanded to almost all disciplines, including medicine. There has been much research on the medical applications of 3-D printing in neurosurgery, orthopedics, maxillofacial surgery, plastic surgery, tissue engineering, as well as other fields. Because of the complexity of the cardiovascular system, the application of this technology is limited and difficult, as compared to other disciplines, and thus there is much room for future development. Many of the difficulties associated with this technology must be overcome. Nonetheless, there is no doubt that 3-D printing technology will benefit patients with cardiovascular diseases in the near future.

Prehistoric genomes reveal the genetic foundation and cost of horse domestication.

The domestication of the horse ∼ 5.5 kya and the emergence of mounted riding, chariotry, and cavalry dramatically transformed human civilization. However, the genetics underlying horse domestication are difficult to reconstruct, given the near extinction of wild horses. We therefore sequenced two ancient horse genomes from Taymyr, Russia (at 7.4- and 24.3-fold coverage), both predating the earliest archeological evidence of domestication. We compared these genomes with genomes of domesticated horses and the wild Przewalski's horse and found genetic structure within Eurasia in the Late Pleistocene, with the ancient population contributing significantly to the genetic variation of domesticated breeds. We furthermore identified a conservative set of 125 potential domestication targets using four complementary scans for genes that have undergone positive selection. One group of genes is involved in muscular and limb development, articular junctions, and the cardiac system, and may represent physiological adaptations to human utilization. A second group consists of genes with cognitive functions, including social behavior, learning capabilities, fear response, and agreeableness, which may have been key for taming horses. We also found that domestication is associated with inbreeding and an excess of deleterious mutations. This genetic load is in line with the "cost of domestication" hypothesis also reported for rice, tomatoes, and dogs, and it is generally attributed to the relaxation of purifying selection resulting from the strong demographic bottlenecks accompanying domestication. Our work demonstrates the power of ancient genomes to reconstruct the complex genetic changes that transformed wild animals into their domesticated forms, and the population context in which this process took place.

Cardiovascular assessment in children: assessing pulse and blood pressure.

Cardiovascular assessment is an important nursing skill in the assessment and management of acutely ill children and children with chronic conditions. This article outlines the differences in the cardiovascular systems of infants, children and adults, and explains how to provide circulatory assessment in children, focusing on assessing pulse and blood pressure.

Magnetic resonance imaging--first human images in Australia.

The use of magnetic resonance imaging, in the demonstration of internal human anatomy and in the diagnosis of disease, has the major advantages that the technique is noninvasive, does not require the use of ionizing radiation and that it can demonstrate neurological and cardiovascular lesions that cannot be diagnosed easily by other imaging methods. Magnetic resonance imaging is derived from the principle that certain atomic nuclei in a strong magnetic field will absorb pulses of radiofrequency energy; when the pulse is finished the nuclei will emit radiowaves at the same frequency. These radiowaves are received by specially designed aerials or coils and the information is collected by a computer which reconstructs an image of internal anatomy in a similar way to that of x-ray computed tomography (CT). By changing the strength of the magnetic fields and the frequency of the radiowave pulses, it is possible to examine different sections within the body. The first magnetic resonance images of humans were obtained in Australia in October 1985 on the research instrument of the Queensland Medical Magnetic Resonance Research Centre, which is based at the Mater Hospital in Brisbane, and is part of the University of Queensland's Department of Radiology.