Open MRI for St Philips Hospital
Author Siemens
Date 15  Mar  2005

New open MR system from Siemens now available at St Philips Hospital

Magnetom C! – Open MRI no more Claustrophobia

Siemens Medical Solutions has introduced the “Magnetom C!”, a new open 0.35 Tesla magnetic resonance imaging system (MRI).

The Magnetom C! is currently the most compact C-shaped permanent magnet that meets routine clinical requirements for neurology, orthopedics, and angiography, as well as paediatrics, oncology, and cardiology.

System advantages include high field technology and excellent image quality.

In addition, the system is open on three sides. The side “entry” to the unit used for all examinations (except those for the head and neck) means the patient has a clear view in all directions.

The patient table moves two-dimensionally, ensuring that the region of interest is always at the center of the magnet to obtain optimum image quality.

The C-shaped design simplifies the examination both for patients and hospital staff. Optimal access and easy examinations are possible even for obese patients.

Fast, high field techniques such as iPAT (integrated parallel acquisition technique) are used to reduce measurement time and increase resolution. The high field technology 2D PACE for example enables the abdominal imaging for patients without breathing.

High field technology is also used in the Magnetom C! for coils and RF channels. The use of up to four channels enables faster examinations. As a result, the patient can be prepared for examination by up to four channels, which enables optimum anatomical coverage. This eliminates the need to reposition coils, reducing examination times and enabling more patients to be examined within the same period of time. This means that hospital workflows can be designed more efficiently.

Background information:

Method of operation in magnetic resonance imaging

The human body is two-thirds water. The water molecule comprises two hydrogen atoms and one oxygen atom.
The nucleus of the hydrogen atom, the proton, may be compared with a magnetic gyroscope. MRI takes advantage of this physical characteristic. In a strong magnetic field – generally 30,000 times stronger than the Earth’s magnetic field – normally arbitrarily rotating protons align parallel or antiparallel to the magnetic field direction.

Depending on the magnetic field strength, an excess of protons align in one direction. This produces a measurable magnetic moment.

By applying electromagnetic radio frequency (RF) energy, the alignment of this excess can be changed. The magnetic moment begins to spin about the field lines of the magnetic field. When electromagnetic stimulation is ended, the excited protons release the energy they have received by generating magnetic fields, which are received by a coil. The greater the excess of nuclei aligned in one direction, the greater the signal strength. That is, the stronger the magnetic field, the greater the signal strength. By spatially changing the magnetic field, one can determine the MR signal’s point of origination. Computer reconstruction programs enable medical images, similar to computed tomography images, to be generated. Contrast in the magnetic resonance image depends on the spatial distribution of water concentrations within the organ, and on relaxation time, which is the time required for the original status to be reestablished once the RF energy is switched off.