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Low Dose (Low Dose Solution of CT [Hardware])

Hardware

Hardware

From the generation of x-rays to the output signal from the Quantum detector, CT system hardware works to minimize exposure for patients of all shapes and sizes.

MegaCool

Designed specifically for Aquilion CT systems, the MegaCool x-ray tube incorporates technology to reduce dose right at the x-ray source. The MegaCool tube features a proprietary PureFocus design that minimizes focal movement and virtually eliminates off-focal x-rays thereby reducing unnecessary radiation to the patient. This innovation employs a durable copper alloy to absorb recoil electrons that may produce unwanted off-focal x-rays. Bearing supports at both ends of the anode axis also add stability and reduce variation in the beam, permitting high-quality imaging to be performed at faster speeds with minimal additional patient dose from the penumbra.

MegaCool

Pre-patient Beam Filter

CT systems utilize contour adaptive bowtie filters to shape the x-ray beam and remove lower energy photons before the beam passes through the collimators and reaches the patient. By removing low energy photons that would only contribute to patient dose and not to image signal, the dose efficiency of the scanner is improved. By shaping the beam, bowtie filters ensure the uniform distribution of photon flux along the detector and high image quality. Available in Large, Medium and Small sizes, these physical filters tailor the beam profile and beam energy based on the type of examination.

Pre-patient Beam Filter

Active Collimator

In Helical scanning, exposure is needed before the start and after the end of the planned scan range in order to reconstruct images at these positions. This over-ranging requires at least one extra rotation, although only a small portion of this data is utilized. Active collimation synchronizes the width of the x-ray beam at the ends of the scan range to the clinically useful area needed for image reconstruction. By eliminating exposure that is not used for diagnosis, patient dose can be reduced by up to 20%.

Active Collimator

Quantum Detector

The most critical component of any CT system is its detector assembly, which converts x-ray photons into digital signals that can be processed to generate images. Based on its global leadership in semi-conductor design, Toshiba Medical has developed the Quantum Detector Data Acquisition System (DAS) that performs exceptionally well under low signal (low dose) conditions. The ability to obtain precisely machined 0.5 mm detector elements enables the use of ultra-thin septa to optically isolate the elements resulting in an extremely high (greater than 90%) geometrical efficiency in the z-axis minimizing patient dose requirements. A revolutionary innovation in DAS design has resulted in the Multiplex sequential sampling chip, which is able to process the data from an entire row of detectors via a single wire. Multiplex chip technology dramatically reduces electronic noise from the crosstalk that occurs in individually-wired detector element designs.

Quantum Detector

Gantry

Computer modeling and iterative design processes ensure the Aquilion gantry operates with negligible vibration and with minimal electronic noise when operated at centrifugal forces as high as 30-G. As a result, the potential for signal degradation from within the gantry is minimized. Finally, specialized stealth paint is applied to the gantry cover itself which works to shield against extraneous EMF interference. This careful attention to eliminating noise from the CT system increases the signal to noise ratio of the acquired images, permitting lower dose scans to be performed routinely.

Gantry