Mediastinal lymph nodes are normally considered abnormal when 10mm short axis. do we worry about the long axis if over 10mm, e.g. 13mm for r4 node ty

Not too concerning: Lymph nodes can normally range in size from 1cm to 1.5 cm. Unless they are getting bigger on serial imaging studies and grow up to 2 CM, there is no need to be worried.Of course what I have stated has to be taken in the context of your medical history which you should provide us before you can receive a reliable opinion. Why was the CT scan of the Mediastinum done? We need history of any symptoms?

Lymph node: I gather you're reading the scan report details. You should just focus on the bottom summary. If you have enlarged lymph nodes, you should thinking about what is causing them to be enlarged. Infection? Cancer? Better take the report to your doctor, who ordered it and review the results with him. He'll give a good idea what to do next.