CORONARY ANGIOGRAPHY
ANGIOGRAPHIC VIEWS PRINCIPLES
- Demonstration of narrowed blood vessels in various projections is of extreme importance.
- The maximum degree of narrowing can be only appreciated if the lesion is demonstrated in true profile.
- Significant lesions may be overlook if visualized in face.
- Coronary artery lesions are frequently eccentric.
- The main coronary trunks can be considered to lie in one of two orthogonal planes
- The LAD and PDA lie in the plane of the interventricular septum,
- RCA and Circumflex coronary trunks lie in the plane of the atrioventricular valves
LAO Projection:
The image intensifier is to the left of the patient.
The spine is to the right of the screen.
RAO Projection
The image intensifier is to the right of the patient.
The spine is on the left of the screen.
Cranial angulation is ideal for visualizing the distal portion of vessels.
Caudal angulation is ideal for visualizing the proximal portion of vessels.
The image intensifier is to the left of the patient.
The spine is to the right of the screen.
RAO Projection
The image intensifier is to the right of the patient.
The spine is on the left of the screen.
Cranial angulation is ideal for visualizing the distal portion of vessels.
Caudal angulation is ideal for visualizing the proximal portion of vessels.
LAO 60° Projection:
- Is looking down the interventricular and interatrial septum plane.
- The AV valves plan seen en face
- All left-sided cardiac chambers appear to the viewer's right
- The LAD and PDA are seen coursing vertically in the middle of the cardiac silhouette following the path of the interventricular septum.
- Is looking down the AV valves plane (Atrioventricular Groove plane)
- The interventricular septum plan seen en-face.
- The two artia and the two ventricles are superimposed.
- The proximal circumflex and proximal RCA are well visualized as they follow the course of the atrioventricular groove.
Cardiac chambers’ locations as viewed in the four standard radiographic projections:
frontal (posteroanterior, PA), lateral, right anterior oblique (RAO), and left anterior oblique (LAO).
The eyes represent the viewer’s line of sight
frontal (posteroanterior, PA), lateral, right anterior oblique (RAO), and left anterior oblique (LAO).
The eyes represent the viewer’s line of sight
Representation of Coronary Anatomy Relative to the
Interventricular septum and Atrioventricular Valve Planes
Interventricular septum and Atrioventricular Valve Planes
- In 1981, Paulin proposed that radiographic projections be named by following the course of the X-ray beam as it passes through the heart.
- The X-ray gantry can be angled in the horizontal and coronal planes.
- In the “cranial” view, the X-ray beam originates caudally and passes through the heart to the image intensifier, which is angled cranially.
- Conversely, in a caudal projection, the X-ray tube is angled cranially and projects the X-ray beam caudally to the image tube.
- The use of multiple oblique views in the anterolateral projections in conjunction with angulation in the caudocranial plane has greatly facilitated optimal visualization of coronary lesions and minimized the problem of foreshortening of the coronary arteries.
Commonly Used Angiographic Views
Left Coronary Artery |
|
20° RAO, 20° caudal |
LMS and LCX |
40° PA cranial |
LAD |
45° LAO, 30° cranial |
LAD and diagonals |
30° RAO, 30° cranial |
LAD |
45° LAO, 30° caudal |
LMS, proximal LAD, and proximal LCX |
Right Coronary Artery |
|
40° LAO |
Proximal and mid RCA |
40° PA cranial |
Distal RCA (PDA and PV branches) |
35° RAO |
Proximal and mid RCA |
RIGHT CORONARY ARTERY -RAO VIEW
RIGHT CORONARY ARTERY - LAO VIEW