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Purpose Noninvasive imaging with hyperpolarized (HP) pyruvate can capture in vivo cardiac metabolism. For proper quantification of the metabolites and optimization of imaging parameters, understanding MR characteristics such as T 2 ∗ s of the HP signals is critical. This study is to measure in vivo cardiac T 2 ∗ s of HP [1-13 C]pyruvate and the products in rodents and humans. Methods A dynamic 13 C multi-echo spiral imaging sequence that acquires [13 C]bicarbonate, [1-13 C]lactate, and [1-13 C]pyruvate images in an interleaved manner was implemented for a clinical 3 Tesla system. T 2 ∗ of each metabolite was calculated from the multi-echo images by fitting the signal decay of each region of interest mono-exponentially. The performance of measuring T 2 ∗ using the sequence was first validated using a 13 C phantom and then with rodents following a bolus injection of HP [1-13 C]pyruvate. In humans, T 2 ∗ of each metabolite was calculated for left ventricle, right ventricle, and myocardium. Results Cardiac T 2 ∗ s of HP [1-13 C]pyruvate, [1-13 C]lactate, and [13 C]bicarbonate in rodents were measured as 24.9 ± 5.0, 16.4 ± 4.7, and 16.9 ± 3.4 ms, respectively. In humans, T 2 ∗ of [1-13 C]pyruvate was 108.7 ± 22.6 ms in left ventricle and 129.4 ± 8.9 ms in right ventricle. T 2 ∗ of [1-13 C]lactate was 40.9 ± 8.3, 44.2 ± 5.5, and 43.7 ± 9.0 ms in left ventricle, right ventricle, and myocardium, respectively. T 2 ∗ of [13 C]bicarbonate in myocardium was 64.4 ± 2.5 ms. The measurements were reproducible and consistent over time after the pyruvate injection. Conclusion The proposed metabolite-selective multi-echo spiral imaging sequence reliably measures in vivo cardiac T 2 ∗ s of HP [1-13 C]pyruvate and products.

Acute pulmonary embolism (APE) is a serious disease which is life-threatening. Since it is crucial for APE patients to assess the changes of cardiac function safely and timely, the imaging research of cardiac morphology and function is becoming more and more important. The correlation of computed tomography (CT) measured cardiac parameters and pulmonary obstruction index (POI) was analyzed to discuss the morphological changes of the heart of APE patients in order to provide a new method to evaluate cardiac functions accurately and effectively. 118 APE patients confirmed with CT pulmonary angiography (CTPA) were divided into high-risk group (47 cases, POI ≥ 20) and low-risk group (71 cases, POI

Cardiomyopathies have been increasingly noted in the captive population of Livingstone's fruit bat ( Pteropus livingstonii ). The aim of this study was to produce a set of repeatable quantitative reference measurements that could be used to assess the cardiac size during radiographic examination of this species. Ventro-dorsal and lateral radiographs (n = 129) from a total of 42 individual Livingstone's fruit bats were examined. The control group radiographs (n = 102) consisted of 34 healthy individuals. Radiographic measurements were taken of structures within the thorax and then converted into ratios. These ratios from radiographs (n = 27) were also calculated for eight individuals with diagnosed cardiomyopathy. Vertebral Heart Scores (VHS) were calculated from right lateral radiographs and compared between the two groups. From all the data, only the width of the cardiac silhouette to the width of the thorax (the W : T ratio) in the ventro-dorsal view and the VHS were found to be significantly different between both groups (P0.05). The group with cardiomyopathies had a mean W : T ratio of 0.59 (±0.005) and a VHS of 9.77 (±0.89), while a mean W : T ratio of 0.54 (±0.004) and a VHS of 8.71 (±0.93) was established for healthy specimens.

Objective: Previous studies have shown associations between body mass index and cardiac structure in both childhood and adulthood. Using Fels Longitudinal Study measurements, we investigate the relationships between a curtailed juvenile state and both adult cardiac structure and function. Methods: A linear mixed-effect repeated measure analysis of variance model is used to test if there is a relationship between juvenile state and each echocardiographic measurement. Results: The curtailed juvenile state is significantly associated with adult left ventricular mass index for both males and females. It is also significantly associated with the interventricular septal wall thickness index and relative wall thickness index for females. In both cases, early juvenile states led to more abnormal structural estimates in adulthood than did late juvenile states. Among cardiac function measurements such as left ventricular ejection fraction and left ventricular shortening fraction, left ventricular ejection fraction is significantly associated with the juvenile state for females. Conclusion: The curtailed juvenile state at the childhood may have a long-term adverse effect on adult cardiac structure and function abnormalities.

En 2013, on estime que 40 à 50% des accidents corporels seraient dus à des défauts d'attention de la part du conducteur. Des études récentes ont mis en évidence la possibilité de détecter des états attentionnels dégradés afin de pouvoir mieux assister le conducteur ; ce thème de recherche représente donc un nouveau gisement de sécurité routière. Cette étude se concentre sur la détection de l'effort cognitif fournit par les conducteurs et cherche, par l'étude de la variation du rythme cardiaque, à identifier un indicateur d'effort sensible sur de courtes fenêtres temporelles.Chacun des 18 participants a passé 8 conditions expérimentales sur simulateur de conduite : la moitié où seule une tâche de comptage était demandée et l'autre moitié en réalisant une tâche supplémentaire de conduite sur simulateur. Il a été demandé aux participants soit d'effectuer la tâche cognitive soit de se relaxer et de ne pas prêter attention aux stimuli présentés (Effort Vs. Relaxation). Afin de réaliser la tâche de comptage, deux types de stimuli auditifs ont été présentés aux participants. Les participants ont effectué les conditions expérimentales dans des ordres partiellement contrebalancés. Le rythme cardiaque et la respiration ont été collectés.Les résultats de différents auteurs ont été répliqués y compris en conduite automobile. Dans les secondes qui suivent un effort cognitif, une légère décélération du rythme cardiaque puis une forte accélération ont été mises en évidence. A l'inverse, en condition de relaxation, une simple décélération cardiaque a été observée. Au terme de notre étude, il s'avère qu'il est possible de distinguer des patterns cardiaques d'effort et de relaxation sur de courtes fenêtre temporelle en observant la variation du rythme cardiaque moyenné sur un nombre conséquent d'épisodes. Toutefois, dans l'objectif de développer des systèmes capables de détecter en temps réel un effort cognitif important, ces dispositifs devront être capables de visualiser l'effort sur un unique évènement. Une piste intéressante consisterait à explorer la faisabilité de la suppression de l'influence de la respiration sur la variation du rythme cardiaque. Si cela s'avère efficace, des assistances pourraient ainsi permettre d'alerter le conducteur ou de pallier ses erreurs lorsque celui-ci ne peut plus assurer la tâche de conduite en raison d'un effort cognitif important.

Cardiomyopathy is a common finding in captive African hedgehogs (Atelerix albiventris) at postmortem exam. To date, treatment attempts have been mostly empirical and unrewarding. The objective of this study was to determine reference cardiac values for captive African hedgehogs based on echocardiogram, electrocardiogram (ECG), and radiographs. Adult African hedgehogs with no clinical signs of cardiac disease (n = 13) were selected. Each animal was anesthetized with isoflurane via facemask and an echocardiogram, ECG, and radiographs were performed. Standard measurements were taken and the descriptive statistics performed. Values were comparable to limited data available in other hedgehog species and other similar-sized exotic species. Two animals were removed from consideration of reference values due to valvular defects that were considered significant. These data are the first establishing cardiac parameters in normal African hedgehogs using radiographic cardiac measurement, echocardiogram, and ECG. Evaluating animals with possible cardiomyopathy may allow for earlier diagnosis and more successful treatment.

Background Hypothermia has been used in cardiac surgery for many years for neuroprotection. Mild hypothermia (MH) [body temperature (BT) kept at 32–35°C] has been shown to reduce both mortality and poor neurological outcome in patients after cardiopulmonary resuscitation (CPR). This study investigated whether patients who were expected to benefit neurologically from therapeutic hypothermia (TH) also had improved cardiac function. Methods The study included 30 patients who developed in-hospital cardiac arrest between September 17, 2012, and September 20, 2013, and had return of spontaneous circulation (ROSC) following successful CPR. Patient BTs were cooled to 33°C using intravascular heat change. Basal BT, systolic artery pressure (SAP), diastolic artery pressure (DAP), mean arterial pressure (MAP), heart rate, central venous pressure, cardiac output (CO), cardiac index (CI), global end-diastolic volume index (GEDI), extravascular lung water index (ELWI), and systemic vascular resistance index (SVRI) were measured at 36°C, 35°C, 34°C and 33°C during cooling. BT was held at 33°C for 24 hours prior to rewarming. Rewarming was conducted 0.25°C/h. During rewarming, measurements were repeated at 33°C, 34°C, 35°C and 36°C. A final measurement was performed once patients spontaneously returned to basal BT. We compared cooling and rewarming cardiac measurements at the same BTs. Results SAP values during rewarming (34°C, 35°C and 36°C) were lower than during cooling (P

In this paper we report on the use of explicit models in the interpretation of echocardiogram images. The problem is considered as an example of a general biomedical image interpretation task and the modelling techniques used can be applied to a wide range of problems. The models are built as a hierarchy of components and the parameters of each component are determined from training examples and prior “expert” knowledge. For each component the model encodes information about the average case and information about the expected distributions, for example sizes, shapes and positions. The models are used within the interpretation process to assess hypothesised matches and to guide further processing. Details of the design and implementation of the model components, the refinements and training techniques and the results of application to the echocardiogram images are presented.

This study was designed to test the efficacy of a paced respiration procedure in reducing subjects' reactions to real and anticipated aversive events. The main hypothesis was that subjects who were taught how to pace their respiration at a slower than normal rate in accordance with a specified signal would show decreased autonomic responsiveness to an electric shock and its anticipation. Three groups of 13 subjects were employed. A Respiration Control group was compared with a group which received all the same stimuli but were instructed merely to pay attention to them without any respiration instructions (Attention Control group) and with a control group for whom the stimuli were or no significance. Results for electrodermal measurement, but not for cardiac measurement, indicated that the learning of a short series of breathing exercises can have significant facilitative effects on reducing autonomic responsivity to a stressful stimulus.

A New Method of Mensuration of the Postero-anterior Heart: A Comparative Study WHETHER or not mensuration is justifiable at all is still a much argued question, dividing the roentgenologists into opposing camps, with cardiologists mostly joining the opposition. Those who practise mensuration say that the diagnosis of heart diseases has been made from measurements and proved against the skepticism of the clinician by electrocardiography, time, and autopsy. Those who condemn the idea have nothing but scornful disdain for “mathematics in x-ray,” and maintain that only the size, shape, and relation of the heart to adjacent organs comprise radiology's contribution to the study of heart disease. When we find such diametrically opposing views, we have to study the problem from the ground up. Review of the Literature.—A review of the literature shows that the idea of mensuration is gaining strength. The text-books of Assmann (1), Schinz (2), Holmes and Ruggles (3), and Kerley (5) give figures for the transverse d...

Cardiac measurement was the height of medical fashion and considered sacrosanct a quarter of a century ago. The Heart and the Aorta; Studies in Clinical Radiology, by H. Vaquez and E. Bordet is still a valuable reference book, copied by many subsequent authors. The more recent work of Hugo Roesler, Geza Nemet, and others, in cardiodynamics, with the brilliant anatomical fact finding by Robb and Steinberg's angiocardiography, places greater importance upon the individual cardiac segments and diminishes the value of cardiac mensuration. This still holds its place, however, as a permanent record for future estimation of progress. Numerous workers have employed many methods of mensuration, each fitting in with the particular needs or whims of the individual investigator. It is not my desire to criticize or compare these. It is rather my purpose to set down the simplest procedure found feasible in my own experience with cardiac mensuration and to point out a practical variation from the standard technic in the...