Myocardial perfusion scintigraphy - interpretation of gated imaging. Part 2.

The first part of the review describes the basic aspects of interpreting myocardial perfusion defects in single photon emission computed tomography (SPECT) scintigraphy. It also presents indications for invasive diagnostics based on stress perfusion defects. This article provides basic information concerning the interpretation of gated SPECT imaging, including such parameters as left ventricular wall motion and thickening as well as left ventricular wall systolic and diastolic function.

Interpreting myocardial perfusion scintigraphy using single-photon emission computed tomography. Part 1.

This article discusses the protocol for myocardial perfusion scintigraphy performed with single-photon emission computed tomography (SPECT). Indications for SPECT are listed with consideration given to the results of the increasingly more common angio-CT examinations of the coronary arteries (multislice computed tomography). The paper also presents basic information about interpreting the results, including the scores of left ventricle myocardial perfusion using the 17-segment polar map, and explains the concept of total perfusion deficit.

Development of a new generation of high-resolution anatomical models for medical device evaluation: the Virtual Population 3.0.

The Virtual Family computational whole-body anatomical human models were originally developed for electromagnetic (EM) exposure evaluations, in particular to study how absorption of radiofrequency radiation from external sources depends on anatomy. However, the models immediately garnered much broader interest and are now applied by over 300 research groups, many from medical applications research fields. In a first step, the Virtual Family was expanded to the Virtual Population to provide considerably broader population coverage with the inclusion of models of both sexes ranging in age from 5 to 84 years old.

A novel medical image data-based multi-physics simulation platform for computational life sciences.

Simulating and modelling complex biological systems in computational life sciences requires specialized software tools that can perform medical image data-based modelling, jointly visualize the data and computational results, and handle large, complex, realistic and often noisy anatomical models. The required novel solvers must provide the power to model the physics, biology and physiology of living tissue within the full complexity of the human anatomy (e.g.

Patient-specific simulations and measurements of the magneto-hemodynamic effect in human primary vessels.

This paper investigates the main characteristics of the magneto-hemodynamic (MHD) response for application as a biomarker of vascular blood flow. The induced surface potential changes of a volunteer exposed to a 3 T static B0 field of a magnetic resonance imaging (MRI) magnet were measured over time at multiple locations by an electrocardiogram device and compared to simulation results. The flow simulations were based on boundary conditions derived from MRI flow measurements restricted to the aorta and vena cava.

The Virtual Family--development of surface-based anatomical models of two adults and two children for dosimetric simulations.

The objective of this study was to develop anatomically correct whole body human models of an adult male (34 years old), an adult female (26 years old) and two children (an 11-year-old girl and a six-year-old boy) for the optimized evaluation of electromagnetic exposure. These four models are referred to as the Virtual Family. They are based on high resolution magnetic resonance (MR) images of healthy volunteers.

A computational model of intussusceptive microvascular growth and remodeling.

Non-sprouting angiogenesis, also known as intussusceptive angiogenesis (IA), is an important modality of blood vessel morphogenesis in growing tissues. We present a novel computational framework for simulation of IA to answer some of the questions concerning the underlying mechanisms of the remodeling process. The model relies on mechanical interactions between blood and tissue, includes the structural maturation of the vessel wall, and is controlled by stimulating or inhibiting chemical agents.

A computational framework for modelling solid tumour growth.

The biology of cancer is a complex interplay of many underlying processes, taking place at different scales both in space and time. A variety of theoretical models have been developed, which enable one to study certain components of the cancerous growth process. However, most previous approaches only focus on specific aspects of tumour development, largely ignoring the influence of the evolving tumour environment.

A coupled finite element model of tumor growth and vascularization.

We present a model of solid tumor growth which can account for several stages of tumorigenesis, from the early avascular phase to the angiogenesis driven proliferation. The model combines several previously identified components in a consistent framework, including neoplastic tissue growth, blood and oxygen transport, and angiogenic sprouting. First experiments with the framework and comparisons with observations made on solid tumors in vivo illustrate the plausibility of the approach.

A multiphysics simulation of a healthy and a diseased abdominal aorta.

Abdominal Aortic Aneurysm is a potentially life-threatening disease if not treated adequately. Its pathogenesis is complex and multifactorial and is still not fully understood. Many biochemical and biomechanical mechanisms have been identified as playing a role in the formation of aneurysms but it is as yet unclear what triggers the process.

Simulating vascular systems in arbitrary anatomies.

Better physiological understanding of principles regulating vascular formation and growth is mandatory to their efficient modeling for the purpose of physiologically oriented medical applications like training simulation or pre-operative planning. We have already reported on the implementation of a visually oriented modeling framework allowing to study various physiological aspects of the vascular systems on a macroscopic scale. In this work we describe our progress in this field including (i) extension of the presented model to three dimensions, (ii) addition of established mathematical approaches to modeling angiogenesis and (iii) embedding the structures in arbitrary anatomical elements represented by finite element meshes.

Computational model of flow-tissue interactions in intussusceptive angiogenesis.

Angiogenesis, the growth of vascular structures, is a complex biological process which has long puzzled scientists. Better physiological understanding of this phenomenon could result in many useful medical applications such as the development of new methods for cancer therapy. We report on the development of a simple computational model of micro-vascular structure formation in intussusceptive angiogenesis observed in vivo.