CT Spiral Phantom

Introduction

The accurate indexing capability and exceptional image quality of the computed tomography (CT) scanners not only guarantee the object’s location and its size and shape, but also improve the diagnosis accuracy. The index and performance parameters of the CT scanners cannot be confirmed without objects of known specifications. The CT Spiral Phantom* provides specific details necessary to confirm the integrity of both conventional and spiral scanning. What makes the phantom unique is that it allows the user to visually evaluate all test results in their image displays.

Applications

The phantom consists of five Lucite® plates of different sizes, all affixed to a flat rectangular base. Specific hole patterns are drilled on each side of these plates. When imaging, the holes within the x-ray field will appear in the phantom images. By the hole appearance, both index and performance parameters can be confirmed qualitatively and quantitatively.

• A supplemental phantom to the CT Performance Phantom, described in a report by the AAPM task force on CT scanner phantoms
• Quality of axial and spiral scanning can be assured
• Accuracy of clinical diagnosis based on the object’s size, shape and location will be improved
• Users can evaluate scanners objectively and independently of CT manufacturers
• No film exposures and no radiation profile measurements are necessary
• All test results can be evaluated visually by the users in their image displays
• Scanner evaluation is more realistic; what you scan, is what you see

This versatile phantom can be used by:

End users, to:

• Set up baseline standards for future reference
• Verify scanner performance in the acceptance test
• Assist in routine equipment quality control testing
• Evaluate vendor-supported imaging protocols
• Customize image parameters for special applications

CT manufacturers, to:

• Evaluate equipment hardware design
• Improve imaging software
• Facilitate equipment installation, calibration, and preventive maintenance

Research laboratories, for:

• Testing image reconstruction algorithms and interpolation approaches

Regulatory agencies, to:

• Set up the standards for CT scanners, and measure their compliance

Specifications

Material:

Lucite

Plate dimensions:

10 x 10 cm, 15 x 15 cm, 20 x 20 cm, 25 x 25 cm

Phantom dimensions:

25 (w) x 20 (d) x 25 cm (h)

Weight:

7.18 lb (8.2 kg)

Typical Spiral CT image of the CT Spiral Phantom shows non-uniform slice geometry, based on the hole appearance on each side of the plate.