Ultra-Fast Look Inside Mummy with MRT

2008-Feb-27 | Researchers from the University of Zürich looked inside a nearly 1,000-year-old mummy from Peru, without causing any damage to the archeological treasure. The anatomists were the first scientists in the world to successfully use magnetic resonance tomography (MRT) using a special measurement method on standard clinical hardware. The spectacular examination was made possible by a team from Siemens Healthcare, whose technical innovation may also soon be helping medical patients.

Doctors have been using MRT for 25 years to generate precisely detailed 3D images of the human body, without the need to expose patients to X-rays. The technique makes use of the weak magnetic properties of hydrogen nuclei, which are found in large numbers particularly in soft human tissue. MRT devices create a very strong magnetic field, which in a 1.5-Tesla MRT can reach about 30,000 times the strength of the earth’s magnetic field. This field aligns the atomic axes, and the device then sends a strong electromagnetic pulse to the hydrogen atoms, causing them to “teeter.” When the atoms align themselves in the magnetic field once again, they transmit radio waves that are used by a computer to calculate the position of the atoms and generate an image of the tissue in question.

The procedure has produced excellent results to date with hydrogen atoms in water and fat. When such atoms are contained in dry tissue, such as proteins or bones, however, the time it takes them to return to their original positions in the magnetic field is much shorter, making the normal calculation and analysis method impossible. For this reason, Siemens experts developed a new measuring method for MRT devices that features very fast signal detection. The key innovation here is that the spatial information is no longer encoded and recorded in parallel lines but instead in a star-shape that originates at the center.

Known as UTE (Ultra-short Echo Time), this new procedure functions smoothly with clinical MRT devices such as the Siemens Magnetom Avanto, which was used for the mummy examination. Here, the system made visible the mummy’s intervertebral disks, cerebral membrane, blood vessels, and embalming fluid residue. The ephyseal plates of the mummy’s upper arm were also clearly recognizable. The scientists who examined the mummy have concluded that it is the body of a boy who was around 15 or 16 years old at the time of death.

UTE also makes it possible to generate images of tissue that previously remained hidden in MRT examinations. The new diagnosis technique could be used in the future to examine metabolic processes in the heart and identify abnormal changes to the body’s metabolism or the brains of Alzheimer patients.