RADIOLOGY

Cardiovascular System

Imaging Techniques:

1 -Plain Radiography:

*The standard plain films for evaluation of cardiac diseases are the PA view & Lateral chest film, the PA view must be sufficiently penetrated to see the shadow within the heart, eg. The double contour of the Lt. atrium & valve & pericardial calcification.

*It provides limited informations about the Heart.

*It provides limited informations about the effect of the cardiac diseases on the lungs & pleural cavities.

*We should assess the following points:

a- Heart (shape & size). b- Great vessels (size, shape), Aortic arch (normally

located to the Lt. of the Trachea, we should exclude the signs of coarctation of aorta).

c- If there is any calcification. d- The main point is the examination of the Lung field

for altered blood flow & if there is any evidence of heart failure.

** Note :Look for any thoracic abnormality (such as Pectus Excavatum).

Normal CXR in PA view

Normal CXR in Lateral view

2- Echocardiography(Cardiac US) :

*It is the major or basic imaging technique used in cardiology.

*It gives important informations about the Morphology& Function of the heart.

*It is an excellent technique to look for:

a- Heart valves. b- Chamber morphology & volume.

c- Determining the ventricular wall thickness. d- Any intra-luminal mass.

3 basic techniques are used inEchocardiography, & they are :

a) M-mode :

*It is a continuous scan over a period of time (5-10 seconds), with pencil – beam of sound directed to the site of interest.

*It can demonstrate chamber dimensions, wall thickness, & valve movement (mainly for Lt. ventricular dimension in systole & diastole).

M-mode

b) Two-dimensional sector scanning(Real time echo.) :

*Demonstrates fun-shaped slices of the heart in motion.

*Standard examination consists of combination of short & long axis views + 4 chamber view.

*Long & short – axis views : cross-section of the of the Lt. ventricle + mitral valve + aortic valve, & it is done by placing the transducer in the intercostal space, just to the Lt. of the sternum.

*4 chamber view : both ventricles, both atria, mitral & tricuspid valves, & it is done by placing the transducer at the cardiac apex & aiming upward & medially.

4 chamber view in 2 dimensional scan

Para-sternal long axis

Para-sternal short axis

Apical 4 chamber view

Para-sternal short axis(at Mitral valve level)

*Changing in the frequency of the sound waves are reflected from moving objects, this change depends on the velocity of the reflecting surface.

*RBCs are used as reflecting surface & the velocity of the blood flow can be measured.

c) Doppler echocardiography(Color, Pulse wave):

Doppler flow measurements are used to :

1 -Measure cardiac output or Lt. to Rt. shunt.

2 -Detect & quantify valvular regurgitation.

3 -Quantify pressure gradients across stenotic valves.

4 -Quantify flow.

3- Trans-Esophageal Echocardiography :

*By placing the U.S. probe in the esophagus immediately behind the Lt. atrium, so it will view the heart from behind.

Trans-Esophageal Echocardiography

(A = normal descending thoracic aorta)

Thank You