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Management of pediatric radiation dose using GE fluoroscopic equipment.

Belanger B, Boudry J - Pediatr Radiol (2006)

Bottom Line: In addition, we describe a new feature that automatically minimizes the patient-to-detector distance, along with an estimate of its dose reduction potential.Finally, two recently developed imaging techniques and their potential effect on dose utilization are discussed.Specifically, we discuss the dose benefits of rotational angiography and low frame rate imaging with advanced image processing in lieu of higher-dose digital subtraction.

View Article: PubMed Central - PubMed

Affiliation: GE Healthcare Technologies, 9900 Innovation Drive, RP-2124, Wauwatosa, WI 53226, USA. Barry.Belanger@med.ge.com

ABSTRACT
In this article, we present GE Healthcare's design philosophy and implementation of X-ray imaging systems with dose management for pediatric patients, as embodied in its current radiography and fluoroscopy and interventional cardiovascular X-ray product offerings. First, we present a basic framework of image quality and dose in the context of a cost-benefit trade-off, with the development of the concept of imaging dose efficiency. A set of key metrics of image quality and dose efficiency is presented, including X-ray source efficiency, detector quantum efficiency (DQE), detector dynamic range, and temporal response, with an explanation of the clinical relevance of each. Second, we present design methods for automatically selecting optimal X-ray technique parameters (kVp, mA, pulse width, and spectral filtration) in real time for various clinical applications. These methods are based on an optimization scheme where patient skin dose is minimized for a target desired image contrast-to-noise ratio. Operator display of skin dose and Dose-Area Product (DAP) is covered, as well. Third, system controls and predefined protocols available to the operator are explained in the context of dose management and the need to meet varying clinical procedure imaging demands. For example, fluoroscopic dose rate is adjustable over a range of 20:1 to adapt to different procedure requirements. Fourth, we discuss the impact of image processing techniques upon dose minimization. In particular, two such techniques, dynamic range compression through adaptive multiband spectral filtering and fluoroscopic noise reduction, are explored in some detail. Fifth, we review a list of system dose-reduction features, including automatic spectral filtration, virtual collimation, variable-rate pulsed fluoroscopic, grid and no-grid techniques, and fluoroscopic loop replay with store. In addition, we describe a new feature that automatically minimizes the patient-to-detector distance, along with an estimate of its dose reduction potential. Finally, two recently developed imaging techniques and their potential effect on dose utilization are discussed. Specifically, we discuss the dose benefits of rotational angiography and low frame rate imaging with advanced image processing in lieu of higher-dose digital subtraction.

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An illustration of how the DRM algorithm compresses the large dynamic range of the original image while preserving the contrast consistency/visibility of structures of interest
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Fig8: An illustration of how the DRM algorithm compresses the large dynamic range of the original image while preserving the contrast consistency/visibility of structures of interest

Mentions: Dynamic range management The importance of the dynamic range of the image system for imaging and dose performance is explained in Section 1. Figure 7 illustrates the improvement in dynamic range that has come with the introduction of flat-panel detector technology. The range of X-ray signal intensity that can be encoded significantly exceeds that of a high-performance digital video camera. However, in order to take advantage of the improvement it is necessary to find a way to display the full range of data without losing details of subtle contrast. This is the classic conundrum of the ‘wide latitude–versus ‘high contrast, short gray scale–film/screen choice. A patented GE proprietary image-processing algorithm called dynamic range management (DRM) overcomes this conflict by reducing the impact of large anatomical structures on displayed image intensity variations without reducing the contrast of small details in the image. This is illustrated in Figs. 8 and 9. Note that anatomical details are visible from the densest portion of the anatomy to the skin line, without blackout or white saturation. DRM processing operates in real time in all fluoroscopic and non-DSA record sequences. It adapts to each image in real time based on the brightness levels in the scene. By providing enhanced visualization of the wide range of data acquired by the flat-panel detector, it avoids the need to readjust imaging conditions, thereby allowing savings in procedure time and radiation exposure.Fig. 7


Management of pediatric radiation dose using GE fluoroscopic equipment.

Belanger B, Boudry J - Pediatr Radiol (2006)

An illustration of how the DRM algorithm compresses the large dynamic range of the original image while preserving the contrast consistency/visibility of structures of interest
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2663641&req=5

Fig8: An illustration of how the DRM algorithm compresses the large dynamic range of the original image while preserving the contrast consistency/visibility of structures of interest
Mentions: Dynamic range management The importance of the dynamic range of the image system for imaging and dose performance is explained in Section 1. Figure 7 illustrates the improvement in dynamic range that has come with the introduction of flat-panel detector technology. The range of X-ray signal intensity that can be encoded significantly exceeds that of a high-performance digital video camera. However, in order to take advantage of the improvement it is necessary to find a way to display the full range of data without losing details of subtle contrast. This is the classic conundrum of the ‘wide latitude–versus ‘high contrast, short gray scale–film/screen choice. A patented GE proprietary image-processing algorithm called dynamic range management (DRM) overcomes this conflict by reducing the impact of large anatomical structures on displayed image intensity variations without reducing the contrast of small details in the image. This is illustrated in Figs. 8 and 9. Note that anatomical details are visible from the densest portion of the anatomy to the skin line, without blackout or white saturation. DRM processing operates in real time in all fluoroscopic and non-DSA record sequences. It adapts to each image in real time based on the brightness levels in the scene. By providing enhanced visualization of the wide range of data acquired by the flat-panel detector, it avoids the need to readjust imaging conditions, thereby allowing savings in procedure time and radiation exposure.Fig. 7

Bottom Line: In addition, we describe a new feature that automatically minimizes the patient-to-detector distance, along with an estimate of its dose reduction potential.Finally, two recently developed imaging techniques and their potential effect on dose utilization are discussed.Specifically, we discuss the dose benefits of rotational angiography and low frame rate imaging with advanced image processing in lieu of higher-dose digital subtraction.

View Article: PubMed Central - PubMed

Affiliation: GE Healthcare Technologies, 9900 Innovation Drive, RP-2124, Wauwatosa, WI 53226, USA. Barry.Belanger@med.ge.com

ABSTRACT
In this article, we present GE Healthcare's design philosophy and implementation of X-ray imaging systems with dose management for pediatric patients, as embodied in its current radiography and fluoroscopy and interventional cardiovascular X-ray product offerings. First, we present a basic framework of image quality and dose in the context of a cost-benefit trade-off, with the development of the concept of imaging dose efficiency. A set of key metrics of image quality and dose efficiency is presented, including X-ray source efficiency, detector quantum efficiency (DQE), detector dynamic range, and temporal response, with an explanation of the clinical relevance of each. Second, we present design methods for automatically selecting optimal X-ray technique parameters (kVp, mA, pulse width, and spectral filtration) in real time for various clinical applications. These methods are based on an optimization scheme where patient skin dose is minimized for a target desired image contrast-to-noise ratio. Operator display of skin dose and Dose-Area Product (DAP) is covered, as well. Third, system controls and predefined protocols available to the operator are explained in the context of dose management and the need to meet varying clinical procedure imaging demands. For example, fluoroscopic dose rate is adjustable over a range of 20:1 to adapt to different procedure requirements. Fourth, we discuss the impact of image processing techniques upon dose minimization. In particular, two such techniques, dynamic range compression through adaptive multiband spectral filtering and fluoroscopic noise reduction, are explored in some detail. Fifth, we review a list of system dose-reduction features, including automatic spectral filtration, virtual collimation, variable-rate pulsed fluoroscopic, grid and no-grid techniques, and fluoroscopic loop replay with store. In addition, we describe a new feature that automatically minimizes the patient-to-detector distance, along with an estimate of its dose reduction potential. Finally, two recently developed imaging techniques and their potential effect on dose utilization are discussed. Specifically, we discuss the dose benefits of rotational angiography and low frame rate imaging with advanced image processing in lieu of higher-dose digital subtraction.

Show MeSH