2. 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.
3. * 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).
6. 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.
7. 3 basic techniques are used in
Echocardiography, & 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).
9. 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.
15. c) Doppler echocardiography
(Color, Pulse wave) :
* 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.
16. 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.
17. 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.
