Changed the order a little – Apologies –
You can change/edit if you want if you want
I started with the basics –
Where are all the chambers
Rule of thirds
The LV since it s most common
The RV – uncommon
The LA – very common but mostly only appreciated on the lateral when very big eg mitral stenosis Elevation of the left main stem bronchus is not commonly seen but it is an important finding
RA hardly ever seen
The LATERAL EXAMINATION – Normal and Abnormal
THE CV STRUCTURES VISIBLE ON THE LATERAL EXAM –
RULE OF 1/3 rds
- Normal Anteriorly
- RV takes up 1/3 of retrosternal space ((Sternomanubrial jn to xiphi)
- LV takes up 1/3 of the hemidiaphragm
- LA 1/3, LV 2/3
- RV > 1/3 of retrosternal space
- LA >1/3 of posterior heart border
- Also elevates left main stem bronchus
Normal vs Abnormal – Left Ventricular Enlargement
Assessment of the Size of the left Ventricle (LV) on the Lateral CXR
Lateral examination of a chest x-ray (CXR) shows the normal in the upper row (a,b) and the abnormal and enlarged in the bottom row (c,d).
The objective evaluation is based on the relative positioning and size of the LV (white arrowhead) in relation to the IVC, (blue arrowhead), and the left hemidiaphragm (pink arrowhead)
Ashley Davidoff MD
NORMAL and RVE
The normal lateral CXR (a,b), shows anterior and superior border of the heart (anterior white arrowhead) occupying 1/3 of the border between the sternomanubrial junction and the diaphragm.
The posterior and inferior white arrowhead shows the posterior border of the heart occupied by the RV taking up 1/3 of the distance of the diaphragm.
Images c and d represent left ventricular enlargement showing that the LV occupies about half the length of the diaphragm, (red arrowhead) while the retrosternal distance is unchanged and normal (white arrowhead).
Ashley Davidoff MD
Normal vs Abnormal – RVE and LAE
LATERAL EXAMINATION RVE AND LAE – MITRAL STENOSIS PULMONARY HYPERTENSION AND COR BOVINUM
71 year old Asian female with rheumatic heart disease dominated by calcific mitral stenosis mild MR, moderate tricuspid regurgitation
Right Atrial Disease on the Lateral _ Only when it is very enlarged
Where is the Right Atrium?
- Axial Imaging Explaining why the RA cannot be see on the Lateral –
- since it is neither anterior nor posterior border forming
- When the RA enlarges-
- it moves laterally and anteriorly see CT below so that it can now be an anterior border forming structure
RAE on the Lateral
Davidoff with Notes Scales and Music of the Axial Imaging of the Heart