Monday, January 31, 2011

Echocardiography Imaging Windows - The Subcostal View

A Subcostal view is obtained by placing the probe 3-4 centimeters under the xiphoid. Echocardiographer should ask the patient to lie on his back and bend his knees, this relaxes the abdominal musculature and a better quality of images are obtained. 
This view is utilized in the immobile patients, patients suffering from COPD or in the patients on ventilatory support where parasternal view is not possible. 

The Four Chamber Plane of Subcostal view - In the four chamber plane the inferior surface of the right ventricle rests on the diaphragm. The echo beam reaches the heart through corner of the liver. The echo beam in this medium is perpendicular to the heart, so interatrial and interventricular septum are easily visualized. There are no drop outs of echo signals in this view as it happens in Apical 4 chamber view, that is why you can easily diagnose and evaluate interatrial and interventricular shunts. 

You can even differentiate among the following interatrial defects. 

The subcostal four chamber view allows to evaluate LV and RV functions as well as valve regurgitations.


Subcostal Inferior Venacava View
You can confirm the morphology of right atrium by tilting the plane inferiorly, this shows the inferior venacava entering into the right atrium. The inferior venacava is lateral and anterior to decending aorta. These two vessels can be distinguished by seeing the pulsation of aorta or by asking the subject to inhale which sucks the blood to the chest and as a result IVC collapses. This view also allows you to diagnose pericardial effusion because you can easily assess the degree of separation of heart from the pericardium. 


Subcostal Short Axis View - 
The short axis subcostal view is same as PSAX( Parasternal short axis view). One can obtain a short axis of the left ventricle. This view allows you to estimate function  of left ventricle and visualize aortic, pulmonic as well as  tricuspid valves. 





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Wednesday, January 26, 2011

Echocardiography Imaging Windows - The Apical 5 Chamber View


If you want to obtain a good apical 5 chamber view then first of all you need to have a high quality 4 chamber view. The fifth chamber of 5 chamber view is Aorta. 
What you have to do is to tilt your probe upwards from the position of 4 chamber view. By doing this you will not see RA and the tricuspid valve but the aorta will be visible in the middle of the screen. There are patients in whom you have to move the probe one intercostal space higher and more lateral. This will give a better alignment of your ultrasound beam with LV outflow tract. 
The main aim of the five chamber view is to display aortic valve and LVOT. This view helps an echocardiographer to assess aortic stenosis or regurgitation. You can also grade the severity of aortic valve lesions with the help of Doppler Imaging. The structure of the aortic valve is better visualized in parasternal view. 



Echocardiography Imaging Windows - The Apical 2 Chamber View


You can easily obtain an apical 2 chamber view from an apical 4 chamber view. The marker of the probe is rotated counterclockwise 90 degrees. To get a better image you can aim towards the left arm pit of the patient. This view helps you to assess the inferior and anterior wall of the Left Ventricle. The anterior wall of the left ventricle is seen on the right of the screen and inferior wall on the left of the screen. The severity of mitral valve lesions are better assessed in this view. 


Tuesday, January 25, 2011

Echocardiography Imaging Windows - The Apical 4 Chamber View

An Apical view  helps an echocardiographer to visualize all the 4 chambers  of the heart. For making this view the probe should be placed at the apex of the left ventricle. The marker or ridge of the probe is oriented towards the right shoulder blade of the patient. It is a good idea to abduct the patient`s left arm as it widens the intercostal spaces which as a result improves the view.

This view can help you to visualize  four chambers of the heart - (Left ventricle, left atrium, right ventricle and right atrium) and the  atrioventricular valves (Mitral and Tricuspid valves). The 4 chamber view also helps an echocardiographer to detect and grade tricuspid and mitral valve lesions, this can be easily done by using color flow imaging and doppler. One can also access size of the ventrilces, ejection fraction and pulmonary vein inflow for accesing diastolic function.






Some points to remember about apical 4 chamber view....
  1. The right chambers are visualized on the left side of the screen and vice versa. 
  2. The lateral wall of the left ventricle is on the right; the septal wall is in the center.
  3. The size of the right ventricle should be about 2/3 of the Left ventricle. 
  4. The function of the right ventricle can be evaluated by looking at the vertical motion of the lateral tricuspid annulus. The right ventricle usually contracts in the longitudinal manner.
  5. Tricuspid valve is few millimeters towards the apex as compared to the Mitral valve.