The ACR MRI Phantom is the benchmark QA tool for MRI systems: designed to validate performance according to American College of Radiology (ACR) standards. It supports both the acquisition and maintenance of ACR accreditation by ensuring clinical compliance.
This cylindrical phantom contains standardized internal structures: grids, inserts, reference bars and low contrast disks. It enables precise assessment of:
- geometric distortion
- spatial resolution
- slice thickness and position accuracy
- signal uniformity
- low contrast detectability
- signal-to-noise ratio (SNR)
The phantom also features "NOSE" and "CHIN" markings to aid orientation and includes a small all-plastic level to ensure correct positioning in the coil. It is fully compatible with standard ACR protocols and suitable for both daily QA and accreditation-level tests.
With its robust, standardized design, it delivers a reproducible, user-friendly, and reliable way to validate MRI system performance.
The Large model is an acrylic cylinder 203,2 mm in outer diameter and 173,4 mm tall. Its usable inner volume measures 190 mm in diameter by 148 mm in length: these two values serve as the reference for the geometric accuracy test, where every measured length must stay within ± 2 mm.
The phantom is filled with a nickel chloride and sodium chloride solution (10 mM NiCl2, 75 mM NaCl) whose relaxation times suit the T1- and T2-weighted sequences of the ACR protocol.
The resolution insert holds three pairs of hole arrays at 1,1, 1,0 and 0,9 mm, used to determine limiting high-contrast resolution in the right-left and top-bottom directions. The slice thickness ramps, inclined at a 10:1 slope, give access to the actual slice thickness through a simple length measurement.
Low-contrast object detectability is assessed on four slices with contrast levels of 1,4, 2,5, 3,6 and 5,1 %. Each slice carries ten spokes of three disks, with diameters decreasing from 7,0 to 1,5 mm.
A bubble of a few cubic centimetres is deliberately left by the manufacturer to absorb thermal expansion of the solution. The phantom should not be shaken, as this breaks the bubble into smaller ones that may adhere to internal structures and interfere with scoring the tests.
Specifications
- Outer diameter: 203,2 mm
- Outer height: 173,4 mm
- Inner diameter: 190 mm
- Inner length: 148 mm
- Volume: 3627 ml ± 10 ml
- Material: acrylic
- Filling solution: 10 mM NiCl2, 75 mM NaCl
- Resolution insert: hole arrays of 1,1 / 1,0 / 0,9 mm
- Slice thickness ramps: 10:1 slope
- Low-contrast objects: 4 slices at 1,4 / 2,5 / 3,6 / 5,1 %, disks from 7,0 to 1,5 mm
- Operating temperature range: 15 to 27 °C
- Non-magnetic bubble level supplied
Models
- ACR-PH1 - ACR MRI Phantom, Large model
- ACR-PHM - ACR MRI Phantom, Medium model
- ACR-PHE - ACR MRI Phantom, Small model
- ACR-PH1 CASE - Transport and storage case, Large model
- ACR-PHE CASE - Transport and storage case, Small model
- ACR-PH1-REFILL - ACR Phantom Refill Kit
- Option - ACR Cradle
