Interventional radiology | EPFL Graph Search

Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs both diagnostic and therapeutic procedures through very small incisions or body orifices. Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct. By contrast, therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement (e.g., stents), and angioplasty of narrowed structures. The main benefits of interventional radiology techniques are that they can reach the deep structures of the body through a body orifice or tiny incision using small needles and wires. That decreases risks, pain, and recovery compared to open procedures. Real-time visualization also allows precision guidance to the abnormality, making the procedure or diagnosis more accurate. These benefits are weighed against the additional risks of lack of immediate access to internal structures (should bleeding or a perforation occur), and the risks of radiation exposure such as cataracts and cancer. Interventional radiology is a set of techniques that allows access to the internal structures of the body through body orifices or very small incisions and guidance with medical imaging. Regardless of the reason for the intervention, the procedure will likely use common elements such as a puncture needle (to pass through the skin), guidewires (to guide through structures such as blood vessels or the biliary or urinary systems), a sheath (which slides over the guidewire and holds the path open without injuring it), and catheters (that allow fluids to be pushed through them). Also common to all intervention radiology procedures are the medical imaging machines that allow the healthcare provider to see what is occurring within the body.

Design of a multi-scale canine-specific model of cardiac electromechanics : a step toward patient-specific modeling

Vincent Forster

Motivated by the growing wealth of biological data and the increasing pathophysiological knowledge at different scales, spectacular progress have been made in comprehensive modeling to understand the complex nature of biological organs, such as the heart. Today, the complexity of cardiac electromechanical models is outstanding; they couple multiple scales, from a genetic level to cellular, organ, and until including whole body interactions, and they already proved their importance to understand the pathophysiology of human diseases such as heart failure and dyssynchrony (Kerckhoffs et al., 2008). However these models fail to faithfully reproduce the behavior of an individual heart. This last decade, a relatively novel approach has emerged as an excellent answer to that drawback: the specific modeling! With the continual grow of computing power; we strongly believe that we now have reached a state where specific models are increasingly feasible and almost ready to be used clinically to assist the physicians. In this study, we present the methodology developed to design a realistic whole heart dog-specific model that includes the four most important components for models of cardiac electromechanics: anatomical, electrophysiology, mechanics and hemodynamics. To specifically fit these components into the model, mechanical anisotropy of the myocardium, active and passive tissue properties, and muscle activation sequence were measured during canine experimental studies. Additionally, high-end imaging tools such as Magnetic Resonance Imaging, Diffusion Tensor Imaging, and micro Computed Tomography were performed on each animal to acquire specific morphological details on anatomy and muscle fibers orientation. Collectively, the methods presented in this paper will lay the framework toward the development of cardiac patient-specific models. These models will be invaluable clinically to predict and optimize the outcome of therapies and interventional surgery on patients

2008

Design of a multi-scale canine-specific model of cardiac electromechanics : a step toward patient-specific modeling

Vincent Forster

2008