A telemedicine system for collaborative work on radiographic coronary video-images

We designed a telemedicine system that supports collaborative work on video-images from coronary cine-angiograms and cine-ventriculograms. Two workstations were connected by ISDN at 128 kbit/s. Coronary cine-angiogram and cine-ventriculogram video-images were transmitted to an image examination workstation before the images were required for analysis (i.e. in a 'pre-fetch' operation). If one workstation changed even a single frame in a video-sequence, then the change was transmitted to the other workstation, rather than the entire video-sequence. To evaluate the performance of the system, the diagnoses made by five cardiology specialists were compared with those recorded in the original report. Coronary cine-angiogram and cine-ventriculogram video-images from 27 patients were used. The cardiologists, who were blinded to the patient information, regenerated the video-images on the workstation and assessed coronary arterial stenosis and wall motion. The kappa scores for clinician agreement with the original reports for ratings of stenosis were 0.54-0.66 and for wall motion were 0.41-0.69. The system performed reasonably reliably and it therefore appears likely to be useful in telemedicine work.