Few fields of medicine have witnessed such impressive progress as the diagnosis and treatment of liver tumors. Advances in imaging technology, the development of novel contrast agents, and the introduction of optimized scanning protocols have greatly facilitated the non-invasive detection and characterization of focal liver lesions. Furthermore, image-guided techniques for percutaneous tumor ablation have become an accepted alternative treatment for patients with inoperable liver cancer. This book provides a comprehensive and up-to-date overview of the role of diagnostic and interventional radiology in respect of liver tumors. The volume moves from background sections on methodology and segmental liver anatomy to the main sections on the diagnosis of benign and malignant liver lesions. An integrated approach, focused on the correlation of ultrasound, CT, and MR imaging findings, is presented. Finally, a full section describes the principles, methods, and results of percutaneous tumor ablation techniques.
Radio frequency ablation (RFA) has become the most commonly used ablative therapy for selected group of patients with liver tumors. To understand the effectiveness of RFA it is important to understand the mechanism of injury to the liver caused by RFA. There is no large animal model to study hepatocellular cancer. This book details the animal experiments carried out by the author in an attempt to create a porcine model of hepatocellular cancer. This book also details the discovery of Transition zone following ablation of liver tissue. This zone lies beyond the zone of cell necrosis and can not be identified by the usual histological techniques. Transition zone lies between necrotic liver tissue and normal liver parenchyma in lesion produced by RFA. This zone has cells showing apoptosis and increased expression of Heat Shock Protein (HSP) suggestive of cellular injury which will eventually lead to cell death. Further research to find techniques to increase the size of "Transition zone" may help in ablating larger areas of liver tumors.
Radiofrequency ablation (RFA) is a procedure to treat tumors of the liver by passing current through a needle shaped applicator placed inside the tumor. The tissue gets heated up and tumor cells are destroyed. Careful planning of the applicator positioning is mandatory for a successful treatment. The desirability of a specific applicator positioning is measured by different criteria, rendering the RFA planning problem a multi-objective optimization problem. In our work we propose a deterministic vector optimization approach to solve the multi-objective RFA treatment planning problem.To allow for numerical optimization routines, feasibility must be expressed as a set of constraint functions. A difficult-to-treat aspect of feasibility is non-overlapping with critical structures such as organs and bones. We propose a modelling approach where the critical structures are approximated as a set of convex polytopes. Then it is a well-known fact that the non-overlapping condition is equivalent to the existence of a set of separating planes -- each plane separating the applicator from one of the polytopes. In this way we can express the non-overlapping condition as a set of analytical constraint functions.A vector optimization approach strives to represent or approximate the set of efficient solutions. In this work we develop the adapted hyperboxing algorithm as a specific sandwiching method for the approximation of a non-convex non-dominated set. As in similar approaches, the non-dominated set is enclosed by a set of boxes, whose size is reduced systematically in the course of the algorithm. The adapted hyperboxing algorithm differs from previous methods in the construction of these boxes, which are spanned by the set of all feasible combinations of a so-called inner and an outer knee point. For the bi-criteria case we prove an a-priori upper bound for the approximation quality achieved by this algorithm.We show with several examples that the developed method can be successfully applied to calculate the non-dominated set of real-data RFA planning problems.
Hepatocellular carcinoma is a major health problem worldwide, with an estimated incidence ranging between 500,000 and 1,000,000 new cases annually. It is the fifth most common cancer in the world and the third most common cause of cancer-related deaths.For years, partial hepatectomy and liver transplantation have been considered as the main curative treatments. However, only 10% to 20% of HCC are resectable. Anatomic location, size or number of lesions, inadequate liver remnant, or co-morbid condition precludes surgery in the majority of patients. Currently, local ablative therapy competes with partial hepatectomy and liver transplantation as primary treatment for small HCC.Radiofrequency ablation (RFA) is considered a promising alternative to surgery. For irresectable tumors, RFA seems to be the most effective treatment among other locoregional therapies. The main advantages of RFA include low morbidity and mortality rates, effective tumor ablation and preservation of maximal normal liver parenchyma.However, despite the high complete necrosis rate of RFA, early tumor recurrence within one year, either local tumor recurrence or new tumor formation,remains a significant problem.
This book provides a carefully selected compilation of challenging cases representative of the situations and pathologies likely to be encountered when performing cardiovascular imaging using CT. The conditions covered include coronary artery disease, anomalous coronary arteries, congenital heart disease, coronary artery bypass grafts, infectious diseases, structural heart disease, tumors, and aortic pathology. The book also provides insights into various scanning techniques geared towards the pre-procedural use of cardiac CTA in patients undergoing atrial fibrillation ablation, thoracic endovascular aortic repair, or transcatheter aortic valve replacement. In addition, scanning techniques for some of the more difficult cases that a cardiac imager may encounter in practice are reviewed. All images are high-resolution reproductions, and subsequent cardiac catheterization images are included for cases in which obstructive coronary artery disease was revealed. Clinical Pearls in Diagnostic Cardiac Computed Tomographic Angiography is specifically designed to meet the needs of residents, fellows, and physicians who have an interest in cardiovascular CT.
The capacity to reliably track, model andcharacterize morphometric changes in anatomicstructures and tumors from 3-D images sequences isextremely valuable in staging disease progression andassessing response to treatment. This book providesthe design and evaluation of two approaches to facilitate clinical assessment in diagnosticradiology. The first is a tool for performingcomparative morphological analysis of ventricles fromMR brain scans of patients with Bipolar Disorder or Asperger''s Syndrome. Ventricles characterizationusing low frequency elliptic Fourier descriptorsprovides an accurate representation while allowingfor reliable group separation. The second is a finiteelement model (FEM) deformable registration techniqueof pre- and post-treatment CT images, to track and quantify tumor response to radiofrequency ablation ofpatients with liver malignancies. Advanced clinicalapplications have become a critical component of thework flow of radiologists as well as the team ofother clinicians. These models should be especiallyuseful for future algorithm development that directly meet the requirements for a range of interventionaland diagnostic procedures.
This book is timely because of the increasing popularity of minimally invasive and cost effective methods to ablate solid tumors. Medical image guided ablation using thermal energy sources such as radio-frequency, microwave, laser, high-intensity focused ultrasound, and cyrogenics have received much recent attention as minimally invasive strategies for the ablation of tumors. This text describes novel and practical image registration methods and mathematical models to predict the cellular response from magnetic resonance (MR) images, which guide and monitor therapy. Many clinical and animal model studies seeking to characterize the biological response to thermal ablations, localized drug release, and other MRI-guided therapies would benefit from this book. This text should be especially useful for medical, engineering, applied mathematics, physics, and computer science students, researchers, and clinicians.
Microwave ablation is a simple, affordable, and highly precise technique. After its successful application in treating liver tumors, it is now widely used to combat renal tumors, adrenal tumors, thyroid nodes, uterine fibroids and other solid tumors. This book presents 40 successful cases of treating these diseases. A series of picture before treatment, after treatment and from different angles is provided for each kind of tumor treatment. In each chapter, step by step operative techniques and illustrations are included. This book also examines CT, NMR and ultrasonography to evaluate the effect of microwave ablation.Editor Ping Liang, is the Director and Professor at Dept. of Interventional Ultrasound, General Hospital of PLA, Beijing, China. Editor Xiaoling Yu is Professor and Chief physician, Editor Jie Yu is Associate Chief physician at the same department.