St. Teresa's Hospital Scanning Department


MRI - Introduction

MRI

MRI (magnetic resonance imaging) scan is a technique that utilizes strong magnetic field and radio waves to produce diagnostic images. The MRI scanner is a tube surrounded by a giant, superconducting magnet (~30000 times of earth magnetic field for 1.5 T machine & 60000 times for 3T machine.)

During the MR exam, the patient lies on a moveable table, with the exam region positioned within the isocenter of the magnetic field inside the bore. The strong magnetic field aligns the protons of hydrogen atoms (mostly from the water molecules within the body); beams of radio waves are then applied to manipulate the net magnetization of the aligned protons. Signals produced are picked up by RF coils (the receiver part of the scanner). Images are produced from these signals with the use of sophisticated image reconstruction algorithms.

The examination is safe and radiation free with no known side effects.

At present we have 3 MR scanners, two ultra-high field 3T (Siemens Prismafit and Skyra) and one high field 1.5 T (Siemens Avanto).

Both the Magnetom Prismafit & Skyra 3T MR systems are the latest state-of-the-art clinical MR scanners. Our Magnetom Prismafit offers better quality images with shorter scan time, empowered by its 64 RF channels, 204 coil elements and the highest magnetic gradient performance in the market. The Magnetom Skyra provides maximum patient comfort with its 70cm wide bore and a short tunnel (~173cm) for maximum comfort. Both scanners are also equipped with the latest “Quiet Scan” technology, minimizing acoustic noise during examinations.