1 Left Atrium Segmentation

Introduction Cardiovascular diseases are the single most important cause of death in the developing world [131]. According to a recent estimate of the World Heath Organization, 16.7 million deaths each year are caused by cardiovascular related illnesses [131]. Their early diagnosis and treatment has become vital for reducing the mortality and improving the quality of life of the patients suffering from such illnesses. The diagnosis and treatment monitoring of cardiac malfunction has improved with the advent of cardiac imaging techniques such as Magnetic Resonance Imaging (MRI) or Computer Tomography (CT). Most hospitals today are capable of providing patients with MRI or CT scans. Research into cardiovascular diseases and their treatment have improved the quality of life and save the National Health Service numerous amounts of money every year. One of the most common causes of deaths in patients with cardiovascular related illnesses are heart strokes and attacks. The American Heart Association reports that 15% of all heart strokes are caused by a life-threatening condition called Atrial Fibrillation [130]. In a recent study, it was determined that nearly 3 million people in the U.S. have atrial fibrillation [129]. Americans over 40 years old have a one in a four lifetime risk of developing atrial fibrillation. It is expected that by the year 2050, the number of people suffering from atrial fibrillation is expected to rise to 5.6 million [129]. Atrial fibrillation is a condition involving the left atrium of the heart. The left atrium is one of the four chambers of the heart. It receives oxygenated blood from the lungs and pumps it into the left ventricle. This blood is then circulated to the rest of the body. In a healthy adult the left atrium pumps blood into the ventricle in a regular rhythm. In atrial fibrillation, the left atrium quivers at abnormal rhythms and is no longer able to pump blood into the left ventricle efficiently. This may cause possible pooling and clotting of blood in the left atrium which can lead to a stroke. The mechanisms of the disease have been described in detail in Chapter 2. Radio-Frequency Catheter Ablation (RFCA) is a surgical procedure used in treating atrial fibrillation where the impulses causing the left atrium to quiver are identified and blocked. RFCA is a highly complicated surgery; in RFCA, clinicians carry out a tedious task of incinerating specific regions of the atrium. This is usually performed with …