Components of an MRI Scanner

Since the commencement of the first commercial MRI units, MRI scanners have undergone considerable evolution both regarding efficiency and hardware upgrades. Incredibly, most people cannot fully tell the different parts of an MRI scanner. This article will help you understand the various components of the device, and explain the functions of each part.

An MRI scanner has the following essential parts:

• Magnet
• Gradient Coil
• Shim Coil
• RF Detector
• Computer

Magnet

Arguably, this is the most important and expensive part of the machine. The device can be equipped with three different kinds of magnets namely; superconducting, resistive, and permanent magnets. Each of these has its pros and cons. However, most of the MRI scanners in the market utilize the superconducting magnet. Magnets are used to produce stable magnetic fields necessary for image capture in the MRI.

Gradient Coil

Within the magnet assembly, you will find gradient coils used to generate different gradients during the imaging process. In a resting state, the MRI's magnetic fields are uniform and consistent over the patient's body region to be scanned. During the imaging, however, the magnetic fields have to be distorted with varying gradients. A gradient can be described as a change in the strength of magnetic field from a point to the other within the patient's body.

Shimming Coils

An MRI scanner has different parts that tend to interfere with the uniform magnetic fields required. These materials result in distorted magnetic fields that need to be made homogeneous. A shim coil is used to streamline the distorted magnetic fields and help in producing a clear and visible image.

RF Detector

RF detectors are located comparatively closer to the patient's body within the magnet assembly. The RF detector's function is to act as the antennae for transmitting signals from the tissue to the scanner, and vice versa to produce the image. The RF detector makes use of energy in the form of non-ionizing radiation.

Computer

An MRI scanner is a sophisticated system that utilizes numerous specific steps and sequences to produce a clear image. These sequences and steps are controlled by a digital computer that is an integral part of the scanner.