Echocardiography Utilizes principle of ultrasound for visualization of heart and great vessels. It uses sound in the frequency of 1-10 MHz. As the frequency of probe increases resolution improves at the cost of reduction of penetration. Due to thichchest wall in adults, probes with frequency range of 2-5 MHz are used and for paediatric application higher frequency of 7.5-10 MHz probes are used
because of thin chest wall.
The underlying principle of cardiac ultrasonography is that speed of sound through tissue is equal to that in water. The transducer which has a Peizoelectric crystal emits a seriels of burst at a given frequency which is reflected from cardiac and other slmctures and is returned to the transducer. These received ultrasound waves ade then displayed as images of cardiac structures on monitor
screen and can be stored in videotape, hard disc or optical disc.
Fig: Showing prihciple of echocardiography. Probe containing Peizoelectric crystal emits series of burst, which are reflected from cardiac structures and is returaed to the transducer. These received ultrasound images are displayed asimages on monitor screen and can be stored in videotape or digitalized fbrmat.
The distance of the i-eflective object from the transducers can be calculated by determining the time required for round trip transit.
Distance (meters)= ( Velocity (meterslsecond))/Time (second)
Veocity = Velocity of soundI
The returning strength of ultrasound signal is directly proportional to the reflective intensity of the object and is in integrated into displayed image.
Echocardiography provides valuable information regarding diagnosis, valvular morphology, etiology, identification and quantification of lesions, cardiac size and function, intracardiac hemodynamics and disorders of pericardium and great vessels.
There are various echocardiographic techniques available:
1) Transthoracic echocardiography
2) Transesophageal echocardiography
3) Stress echocardiography:
a)Exercise
b) Pharmacological
4) Fetal echocardiography
5) Contrast echocardiography
6) 3-D echocardiography
7) Intravascular ultrasound
Most commonly used technique is transthoracic echocardiography (TTE). Others require further skill and expertise, once the physician has acquired the skills of TTE.
Niche Areas in Cardiology and Role of Echocardiography
Echocardiography is a very important tool in diagnosis of cardiovascular diseases and is used virtually in all categories of cardiovascular diseases. There are certain areas where echocardiography provides a definite answer with minimal discomfort and risk and may obviate the need for catheterization in selected patients. Some examples are listed below:
1) LV function
a)Systolic
b) Diastolic
2) Cardiac masses
a) LV-tumors, clot or vegetations
b) RA/RV masses
3) Diagnosis of hypertrophic cardiomyopathy
4) Pulmonary hypertension
5)To diagnosis complication of myocardial infarction, pseudoaneurysm,aneurysm, thrombus and VSD
6) Pericardial diseases
7) Evaluation of valvular stenosis and regurgitation
8) Prosthetic valve evaluation
9) To diagnose ischemia and viability by stress echocardiography
10) Congenital heart disease e.g. TOF, DORV, ASD, VSD, etc.
because of thin chest wall.
The underlying principle of cardiac ultrasonography is that speed of sound through tissue is equal to that in water. The transducer which has a Peizoelectric crystal emits a seriels of burst at a given frequency which is reflected from cardiac and other slmctures and is returned to the transducer. These received ultrasound waves ade then displayed as images of cardiac structures on monitor
screen and can be stored in videotape, hard disc or optical disc.
Fig: Showing prihciple of echocardiography. Probe containing Peizoelectric crystal emits series of burst, which are reflected from cardiac structures and is returaed to the transducer. These received ultrasound images are displayed asimages on monitor screen and can be stored in videotape or digitalized fbrmat.
The distance of the i-eflective object from the transducers can be calculated by determining the time required for round trip transit.
Distance (meters)= ( Velocity (meterslsecond))/Time (second)
Veocity = Velocity of soundI
The returning strength of ultrasound signal is directly proportional to the reflective intensity of the object and is in integrated into displayed image.
Echocardiography provides valuable information regarding diagnosis, valvular morphology, etiology, identification and quantification of lesions, cardiac size and function, intracardiac hemodynamics and disorders of pericardium and great vessels.
There are various echocardiographic techniques available:
1) Transthoracic echocardiography
2) Transesophageal echocardiography
3) Stress echocardiography:
a)Exercise
b) Pharmacological
4) Fetal echocardiography
5) Contrast echocardiography
6) 3-D echocardiography
7) Intravascular ultrasound
Most commonly used technique is transthoracic echocardiography (TTE). Others require further skill and expertise, once the physician has acquired the skills of TTE.
Niche Areas in Cardiology and Role of Echocardiography
Echocardiography is a very important tool in diagnosis of cardiovascular diseases and is used virtually in all categories of cardiovascular diseases. There are certain areas where echocardiography provides a definite answer with minimal discomfort and risk and may obviate the need for catheterization in selected patients. Some examples are listed below:
1) LV function
a)Systolic
b) Diastolic
2) Cardiac masses
a) LV-tumors, clot or vegetations
b) RA/RV masses
3) Diagnosis of hypertrophic cardiomyopathy
4) Pulmonary hypertension
5)To diagnosis complication of myocardial infarction, pseudoaneurysm,aneurysm, thrombus and VSD
6) Pericardial diseases
7) Evaluation of valvular stenosis and regurgitation
8) Prosthetic valve evaluation
9) To diagnose ischemia and viability by stress echocardiography
10) Congenital heart disease e.g. TOF, DORV, ASD, VSD, etc.
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