The most mature application in telemedicine generally is teleradiology. In the vast majority of cases, this involves the transfer of still images in prerecorded mode. There are circumstances in which this is also done in real-time, usually as part of a real-time teleconsultation. However, the most common application in which still images are transferred in real-time is telepathology.
Telepathology: Telepathology remains an active area of research. Certain forms of telepathology are well suited to prerecorded telemedicine. However, when an immediate diagnosis is required, for example during a surgical operation, real-time telepathology must be used. In practice, most diagnoses can be made based on the real-time video pictures, without the need to transmit high-resolution still pictures as well.
Teleradiology: Real-time teleconsultation between physicians in different hospitals has been demonstrated using videoconferencing for face-to-face interaction, combined with the simultaneous transfer of still images in a parallel data channel. This allows a radiologist to discuss a case with the referring doctor while both examine the same images. Such techniques, while probably providing an improved standard of care, remain too expensive for routine use. Mobile phone links, which have the advantage of wireless connection, have been used to transfer radiology images to notebook computers for reporting by the radiologists on duty out of hours. In a study of 30 head computerized tomography studies of emergency cases, there were no major discrepancies in 82 out of 90 interpretations (91%), suggesting that portable radiology workstations may permit radiologists to provide rapid consultations from anywhere within the mobile phone coverage area.
Accident and emergency telemedicine: Attempts to improve communication between emergency ambulances transporting patients and the staff at the receiving hospital have centered on the use of mobile phone links to transmit data such as ECG signals. This allows, for example, prehospital thrombolysis to be started by paramedical staff before arrival at the hospital which reduces call-to-needle times. Still images have also been sent from ambulances and transmission rates of about 15 pictures/min are possible. Widespread use of image transmission will probably depend on better telecommunications. Once the patient has arrived at the hospital, mobile phones with built-in cameras can be useful in obtaining a second opinion. There have been encouraging trials in wound care and burns. In one trial of teleconsultation regarding injuries to ﬁngers, the mean time between taking photographs to their reception was three to four minutes.