1) What are the best pediatric IR programs in the country?
There are one-year peds-IR fellowships available for pediatric radiologists and interventional radiologists, however I don't think there's a formal boarding process like with IR and neuro-IR. Boston Children's is a good example:
http://www.childrenshospital.org/ce...sidencies/interventional-radiology-fellowship
2) What pediatric diseases are treated by IR?
There are a lot of overlaps with adult body-IR. The unique procedures include treatment of lymphatic malformations and vascular tumors, which are less common in adults. The fellowship at Boston Children's also does peds-neuro-IR procedures, which have pretty much left most adult body-IR fellowships.
3) Are there any opportunities for long-term physician-patient relationships in pediatric IR (ie, besides HHT patients)?
The peds-IR attending I worked with had patients voluntarily driving 2 hours to come see him at his new office. However, I think his "long-term" just consisted of yearly checkup to verify that lymphatic malformation didn't recur.