Let me explain the mechanism of this 1992 system. This is a CT-based system. The first generation utilized a CT-based table instead of a catheter table. The X-ray tube is not visible, because it is inside the CT table. Above there is a large detector called an "I.I.", (Imaging Intensifier) that comprises of a vacuum tube and an X-ray enhance electron. It is amplified, and provides an output image on the fluorescent screen which is suspended from the ceiling. It uses a vacuum tube and is equivalent to the FPD in current systems. At the time, CT systems were floor-mounted and not movable.Threedimensional C-arm rotation was not possible then.
Dr. Arai (Figure 3) first came up with the Angio CT hybrid idea. This was during the period when he was working at Aichi Cancer Center in Japan. His main focus was to avoid transferring the patient form the CT to the Angio room and vice versa. Dr. Arai has always emphasized the importance of not moving patients in between examination rooms. Moving the patient takes a lot of effort and requires support from a number of hospital staff. For example, there are X-ray tubes, ECG electrodes, other cables, and tubes involved in Angiography systems. If these have to be disconnected to move the patient, it places a great burden on them, as well as the staff members involved. It is also time consuming. Therefore, it is important that all the procedures can be performed while sharing one table between Angiography and CT scan. CT is used to examine the lesion in advance. While the Angiography C- arm is mostly used to confirm the results of the examination, and to evaluate results before and after the examination.
The need to perform Angiography and CT using the same patient table within a single room led to the concept for the world's first Angio CT system. At the time, the initial development was mainly handled by the CT team rather than the VL team.
1994 - Introduction of the C-arm
In this year the C-arm was first introduced in the Angiography system. This C-arm was an ancestor of the Alphenix. Originally, the arm was suspended from the ceiling. This not only allowed scanning of the patient from the front, but also made it possible to perform scanning from various angulations.
However, the CT was still fixed to the floor, requiring a specially designed patient table. This was the reason for a very long tabletop. Unlike current Angio CT systems in which the CT system can move over rails, a CT system fixed to the floor was used in combination with a long tabletop like the one shown in Figure 4 (1996). However, the maximum range how far the tabletop could be extended was limiting the desired patient coverage for CT scanning. Here it is illustrated how the system looked during the period of technological transition.