| |
| Objectives |
| |
| The objectives are covered by the basic anatomical principles and the 20 standard views. At the completion of this chapter, the student will be able to: |
| |
- Identify the Cardiac Planes
- Describe the Anatomy-Image Correlation
- List the ASE-SCA Nomenclature (2D)
- Describe Probe Manipulation and Insertion
- Recognize the Anatomy in each of the 20 Standard Views.
|
| |
| Introduction |
| |
| The heart is a three dimensional structure that is displayed on a two dimensional angiographic image. Echocardiography cuts a tomographic plane in space, through which, the heart moves. Since the heart may have slightly different orientation from patient to patient, standard views have been develolped that allow comparison from intra-study and inter-study images. |
| |
The anatomic view of the heart depends upon the acoustic window, the probe position, and the longitudinal (electronic) angle of the ultrasound beam. Acoustic windows can be either transthoracic, transesophageal, epiaortic or epicardial. The ASE-SCA has developed standard nomenclature and views for transesophageal and transthoracic acoustic windows . The transesophageal section presents the standard views followed by the nonstandard views. The standard views should be obtainable in most patients. Non-standard views offer some advantages, but are not obtainable in most patients. These non-standard ASE-SCA views are discussed in the Advanced Section of E-echocardiography.com |
| |
| Cardiac Motion |
| |
The heart moves during contraction and relaxation. During the contraction-relaxation process the three dimensional heart is moving thru the two dimension cut of the 2D echocardiographic sector scan. The types of cardiac motion are:
|
- Translation
- Rotation
- Torsion
|
|
|
|
| |
Image Translation |
Image Rotation
|
Image Torsion |
|
| |
| Translation is the movement of the heart in the chest. A swinging back-and-forth motion in the thoracic cavity is an example of translation. Rotation is a circular motion of the heart around the long axis of the heart. Torsion is the wringing motion of the heart where the base is stationary but from apex to base the heart contracts further, much like wringing a wet cloth. All of these motions will cause the heart to pass through the ultrasound's sector scan. Therefore, when interpreting views of the heart, slightly different angles can cause small variations in the structures seen in the scan. Some structures will be seen to pass through the view which can result in some interesting artifacts or possible misinterpretation of the scan. |
| |
| Cardiac Axis |
| The heart is not anatomically located in the thorax that allows it to be easily described by classical anterior-posterior or caudad-crainial planes. The heart is about 30 degrees off the caudad-crainial axis. Therefore, the heart is described by its own internal axis. The axis from the base of the heart to the apex of the heart is called the long axis of the heart (LAX). If all four chambers are visualized then the view is called the 4 chamber view (4CV). Perpendicular to the 4 chamber view is the a long axis view of the heart where 2 chambers are visualized, called the 2 chamber view (2CV). Perpendicular to the 2 chamber view and the 4 chamber view is the short axis view (SAX) of the heart. In the short axis view the classical view of the "doughnut" of the left ventricle is visualized. |
|
|
| |
|
|
| |
