I found an interesting article in J Telemed Telecare. 2005;11(6):271-5 on various business models followed by various teleradiology providers worldwide. According to Mun Sk et al A number of new diagnostic radiology services have emerged which use teleradiology. The main themes include: (1) stand-alone teleradiology practice; (2) the "Nighthawk"/on-call coverage; (3) solo radiologist practice; (4) expert/second-opinion teleradiology; (5) a global virtual radiology service based on workload sharing and reallocation.
In our own company Teleradiology Providers we follow the model of expert opinion as we have done in various centres around Delhi and Second opinions as sent over to us & sharing of work in the inetrnational market.