The present invention utilizes standard SSH technology and the rsync and scp protocols to enable secure, cost-effective, two-way transmission of medical data over the Internet and through the hospital's firewall using push and pull mechanisms. The hospital firewall is traversed through the use of an agent located behind the hospital's firewall which uses both a push mechanism and a pull mechanism to transmit raw scan data. In other words, the present invention transfers data from the hospital to the third party by initiating a data push mechanism from behind the hospital firewall; and transfers the processed data from the outside third party back into the hospital by initiating a data pull mechanism from behind the hospital firewall. The afore-mentioned agent acts as a broker for the foregoing data transmission and also encodes how the data should be handled upon being received by the hospital.