As regards the bone scan please let me clarify some points:
The bone scan is not a study that can give diagnosis of any and every problem. You have mentioned that patient had swelling in legs and pedal edema
but you have not mentioned age of patient.
Generally speaking, bone scan is not done for evaluation of swelling though pain anywhere in body may be evaluated with bone scan (some times radiological evaluation eg CT/MR may be combined if needed)
You have mentioned that the bone scan done in 2 phases one before injection and one after injection:
Please note that bone scan is done only after injection though at times 2 phase and 3 phase scan is done that means scan is done twice or thrice after giving injection (the latter in situation where there is suspicion of bone infection
or stress related issues eg stress fracture
Now as regards the report:-
1. The Radiologist
who has read the report may have found only degenerative change and nothing else.
2. Incase this is degenerative cause, nothing to worry as this is common at certain age group. However, one must know the cause of pedal edema and other swelling as you mentioned.
3. As it appears in obese
patients it is not uncommon to have degenerative bone disease
as mentioned in the report.
4. As bone scan does have high sensitivity it usually does not miss any pathology and most of the time bone scan is most relied upon to exclude metastatic lesion and is superior to other tests.
However if the scan is available please send the scanned copy of the same I can comment and reply, if anything is missing in the finding as without personally seeing the bone scan one cannot say much about it.
Do write back for further discussion on this.