Special Features of the New System
- SSMD matrix detector
This system employs the SSMD3 (selectable slice thickness multi-slice detector) technology that was developed for the Aquilion Multi-Slice system, Toshiba's top-of-the-line CT scanner. The detector is composed of about 20,000 elements, which makes it possible to obtain highly accurate data even in the longitudinal direction, as well as in the axial direction. The elements for the narrowest 0.5-mm slice widths are placed at the center, making it possible to achieve high-quality imaging with isotropic2 resolution.
- High-speed scanning
Two image slices are acquired in each revolution, and each revolution is performed in 0.75 seconds for high-speed scanning. It is possible to scan a range of 15 cm in only 4 seconds with helical scanning1 and a slice thickness of 10 mm. Short scanning times allow patients to be examined more quickly, and patient throughput is increased , the load on the tube is reduced and there is less need to wait for cool-down.
- Improved examination efficiency
The system employs the MUSCOT4 reconstruction technology developed for the high-level Aquilion Multi-Slice system, which makes it possible to obtain images with various slice widths using the same raw data. Thus, by using thin slices from the beginning, it is possible to eliminate the rescanning that conventional technology can require. High-speed processing means that reconstruction can be completed in 1 second.
- Outstanding ease of operation
The system is provided with various features for handling large amounts of multi-slice data with ease. These features include an image matrix display for managing large numbers of images efficiently and advanced film processing that displays the images in the format that will be output to film (virtual films), permitting efficient editing.
- Realtime technology
Because reconstructed CT images can be displayed during scanning, at the world's fastest display speed of 12 images per second, it is possible to confirm the position and direction of scanning and immediately check the contrast effect. This system is therefore particularly well suited to the examination of emergency patients. In another application of this technology, a standard feature of the system is Toshiba's unique "SureStart" technology, which automatically detects the inflow of contrast medium and starts the scan at the optimal time. Today, "SureStart" has established itself as an essential function in contrast examinations.
- Reduced patient exposure
It is possible to continuously vary the tube current while performing helical scanning, thus ensuring that X-ray exposure is appropriate for each region scanned. This minimizes patient exposure and makes it possible to obtain high-quality images in all regions, irrespective of their location. In addition to the normal scanning mode, a low-dose mode is available, so patient exposure can be further reduced depending on the objective of the examination.
 Notes
- Helical Scanning Method
A scanning method in which data is continuously acquired in a helical fashion along the body axis by combining continuous rotation of the X-ray tube and continuous sliding of the patient couch. Compared with the conventional method of acquiring data intermittently by shifting the patient couch for each slice, the helical scanning method allows a wide range, such as entire organs, to be scanned at high speed.
- Isotropic
Isotropic means having the same properties regardless of direction, and isotropic scanning makes it possible to generate 3D images in which the resolution is the same in the x, y, and z axes, resulting in cubic voxels. (Toshiba uses this word to mean equally high resolution in each axis.) Professor Katada of Fujita Health University has stated that this is one of the most important features of multi-slice systems.
- SSMD
This is the abbreviation for "selectable slice thickness multi-slice detector." As shown in Figure 4 ("Structure of the SSMD Detector"), SSMD technology makes it possible to select any desired slice thickness by selectively combining the output from precision detector elements. The combined output is sent to a data collection system (DAS). There are two DAS systems in a dual-slice system.
- MUSCOT
This is the abbreviation for "multi-slice cone-beam tomography."
This is a unique method developed by Toshiba for reconstructing multi-slice data. By employing filter processing in the slice direction, it is possible to reconstruct high-precision images free of artifacts.
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