Case contributed by Frank Gaillard
Diagnosis certain


Poor exercise tolerance.

Patient Data

Age: 85 years
Gender: Female

Chest x-ray


PA and lateral chest x-rays demonstrate markedly enlarged cardiac silhouette. There is a double contour to the right heart border and splaying of the carina. 

The aorta is somewhat ectatic. There are no overt features of congestive cardiac failure at this time.  


Single image from a CT (obtained for unrelated reasons) at the level of the heart confirms cardiomegaly, with dilatation of all chambers (the left atrium most prominent). No pericardial effusion.

Annotated outlines

Annotated image

Contours - Splayed carina (red), and double contour. When correlated to the CT it is evident that the most lateral contour is due to the right atrium (blue) and the more medial contour due to the left atrium (orange).

Cardiothoracic ratio

Annotated image

Figure 1: annotated x-ray of this same patient

Cardiothoracic ratio is measured on a PA chest x-ray, and is the ratio of:

  1. maximal horizontal cardiac diameter
  2. maximal horizontal thoracic diameter (inner edge of ribs / edge of pleura)

Figure 2: A normal measurement should be less than 0.5. 

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.