CT ACR 464 Phantom

CT ACR 464 Phantom

Leverage a sophisticated design to comply with guidelines, and more.

  • The only phantom needed to meet American College of Radiology (ACR) accreditation guidelines
  • Versatility permits checking of multiple parameters, efficiently

With the CT ACR 464 Phantom, you gain a multi-functional resource for your department.

Not only is it essential for compliance, it allows the testing of: positioning and alignment; CT number accuracy; slice thickness; low contrast detectability, image resolution; image uniformity; spatial resolution; inter and intra plane distance measurement accuracy; and more.


  • Single phantom permits checking multiple parameters
  • Compact design makes the phantom safe to store and easy to transport
  • Automated software allows for fast and simple reporting of results

Standard CT ACR 464 Phantom Modules


Optional Low Contrast Detectability Module

Expand the capabilities of your 464 with the new Low Contrast Detectability Module. This module tests the low contrast detectability of even the most demanding CT scanners using three contrast levels, scientifically-sized objects, and noise-robust redundancy.

  • Three precisely formulated contrast levels test performance across a range of scanners and protocols
  • Robust against noise with two objects at each size and contrast
  • Evaluates radial dependence of contrast detectability
  • Tests full-slice and sub-slice detectability
  • Every phantom is manufactured in-house by Gammex and independently verified before shipment
  • Fits perfectly with your CT ACR 464 Phantom and/or Extensions
Low Contrast Detectability Module

Low Contrast Detectability Module Specifications

Material: Epoxy interior, with a shell of our new Zero HU High Equivalency Solid Water
Diameter: 20.0 cm (7.9 in)
Length: 4.0 cm (1.57 in)
Contrast Levels: 0.3 % (3 HU), 0.6 % (6 HU), 1.0 % (10 HU)
Sizes at Each Contrast Level: 25 mm, and 2 at each of 1.5, 2, 3, 4, 5, 7, 9, and 12 mm
Sizes of Sub-slice Objects: 2, 3, 5, 7, and 10 mm (cylinder diameter and length), at each contrast level

Optional High-Contrast Resolution Module

Test high resolutions easily with this new module for
your Gammex CT ACR 464 Phantom family. This module
features line pairs with resolutions up to 32 lp/cm, all
in sizes large enough to be easy to visualize and to be
robust for automated analysis.

  • Incorporates all resolutions of the CT ACR 464 Phantom
  • Includes high resolutions up to 32 lp/cm
  • Large bar patterns (1.5 cm x 1.0 cm x 4.0 cm) for ease of visualization and analysis
  • Designed for manual and automated analysis
    • Includes solid samples of resolutions materials for accurate results during software analysis
  • Zinc high-contrast material provides visibility without over-ranging scanners
Acr 464 High Res Module

High Resolution Module Specifications

Material: Epoxy interior, with a shell of and core of our new HE CT Solid Water®
Diameter: 20.0 cm (7.9 in)
Length: 4.0 cm (1.57 in)
Resolution Pattern Size: 1.5 cm x 1.0 cm x 4.0 cm
Resolutions Tested: 2, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 and 32 lp/cm
Automated Analysis Features: Solid material samples improve computational analysis Large pattern sizes enable robust evaluation
Contrast Material: Zinc

Optional Slice Sensitivity & Geometric Evaluation Module

The Slice Sensitivity & Geometric Evaluation Module includes wires, bead ramps, and spherical objects to validate slice thickness, slice sensitivity profile, and system geometry.

  • Measure slice thickness with an opposed pair of wire ramps
  • Measure slice thickness and slice sensitivity profile with 2 opposed pairs of bead ramps
  • Calculate Modulation Transfer Function with one-off vertical wire
  • Check geometric accuracy with a set of 8 acrylic spheres
  • Perform MTF measurements with BB’s of two different sizes
  • Easily visualize test objects with clear construction and modular design
  • Designed for manual and automated analysis
Acr 464 Geometry Module

Slice Sensitivity & Geometric Evaluation Module Specifications

Material: Epoxy interior, with a shell of and core of our new HE CT Solid Water®
Diameter: 20.0 cm (7.9 in)
Wire Ramps: Tungsten wire, 0.05 mm diameter
Bead Ramps: One opposed set with 0.18 mm tungsten carbide BB’s, and one with 0.28 mm tungsten carbide BB’s
MTF BB’s: 0.18 mm and 0.28 mm
MTF Wire: Tungsten wire, 5 degrees off-vertical, 0.05 mm diameter
Acrylic Spheres: 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0,and 10.0 mm diameter


Material: PolZero HU Solid Water®
Diameter: 20.0 cm (7.9 in)
Length: 16.0 cm (6.3 in)
Weight: 5.3 kg (11.7 lbs)

Imbedded Test Objects

MaWater Equivalent Linearity Rod: Solid Water, Zero HU
Bone Equivalent Linearity Rod: Bone tissue equivalent material
Acrylic Linearity Rod: Cast Acrylic
Polyethylene Linearity Rod: Low Density Polyethylene
Low Contrast Module Matrix: Ciba Geigy CB4 epoxy or equivalent
Low Contrast Rods: Ciba Geigy CB4 epoxy (density adjusted to yield 6 ±0.5 HU difference) or equivalent
Tungsten Carbide Beads: 0.28 mm (0.011 in) in diameter grade 25 tungsten carbide beads
Line pair Material: 6061 Aluminum and Polystyrene
Steel Beads Intra-module Homogeneity: The mean ROI values within any module, test objects excluded, can differ by no more than 2 HU
Intra-phantom homogeneity modules 1, 3 & 4: The average CT number a module must meet the requirements of 0 ±5 HU
Additional Accessories: Phantom Stand, Soft Case, Automated Analysis Software


CT ACR 464 Phantom Body Ring

The CT ACR 464 Phantom can easily be inserted into the 464 Body Ring adapter to permit fast imaging QA for a better indication assessment of a scanner’s performance with large patients.

CT ACR 464 Phantom Extensions

The CT ACR 464 Phantom Extensions plates accurately represent scatter effects from widebeam CT scanners, thus eliminating the need to add a water bolus or other material when measuring the Phantom.