MRI Phantoms and Image Quality Control

Generating accurately rendered images is paramount to any radiological practice. The use of MRI phantoms in calibration and quality control ensures better image generation to make accurate diagnosis of diseases.

In this article we are going to talk about the different types of phantoms used and what they test on an MRI unit. 

MRI units must consistently produce high-resolution images of anatomical structures to provide doctors with an appropriate treatment plan for patients. 

Misdiagnosis from poor image quality alone can account for costly malpractice suits against radiology groups and hospitals throughout the world.

Distorted and unclear images can lead to delayed treatments, and undiagnosed or missed diseases. Patients are relying on a quick and accurate diagnosis.  Any delay in the treatment plan can lead to more harm or death to the patient.

Here are three reasons to use an MRI phantom for quality control in the clinical environment

1. A proper QC program for MR units is the law in America
2. Imaging testing is Part of the quality control checklist for MR units.
3. Scheduled phantom tests avoid costly malpractice suits. And finally, ensures image integrity

In the US Quality Control is the law (Medicare Improvement Patients and Providers ACT of 2008) MIPPA. The American College of Radiology requires a series of measurements tested with an MRI phantom on weekly/annual basis for a site to be accredited.

“having a good phantom and performing a series of weekly tests are important to the image integrity and keeping the site accredited. “

Imaging departments looking to purchase a new MR unit can use Phantoms to test different scanners for purchase. The phantoms assess system stability and the comparability of measurements across various MRI units. The tests done with the same phantom should yield similar results to ensure validity among the different units.

Which phantoms are used?

The ACR American College of Radiology MRI accreditation phantom is constructed of acrylate plastic, glass, and silicone rubber. Ferromagnetic materials have been excluded. The unit is a cylinder 20.4cm in diameter by 16.5cm in length. Internal dimensions are 19.0 cm diameter by 15.0 cm in length.

A good phantom test on any MR unit should determine the following

• Radio frequency (RF)
• Static mag fields
• Geometric linearity
• Gradient amplitude
• Slice position and profile
• Image uniformity
• Resolution high contrast detectability
• SNR
• Accuracy and precision of proton density
• And system constancy

Phantoms can even be used to test other phantoms for their accuracy in the imaging field.