Follow-up x-ray
I can give you a scenario that may shed a little light on your situation.
If a patient is sent for a chest x-ray say on November 1, 2009 and the impression is pneumonia and the treating physician says come back in 4 weeks and we will re-examine you and send you for a follow-up x-ray, the rule of thumb is that the patient, while in 4 weeks may clinically be "healed" and no longer have those clinical findings of penumonia, they are not radiologically free of the pneumonia until an x-ray is done. So, when they present to the Radiology lab for that follow-up x-ray, for all intents and purposes, they continue to carry the diagnosis of pneumonia until that x-ray is read and the impression states negative/normal/no pneumonia (or however they choose to phrase it).
I hope this helps put it in perspective...coding, the ever changing (and frustrating) career!
Have a great holiday!
Joyce