MRI Scanner

Magnetic resonance imaging (MRI), or nuclear magnetic resonance imaging (NMRI) refers to a sophisticated medical technique used in radiology. This medical imaging technique is commonly used to visualize internal structure and functions of the body organs. The images captured by MRI technique give detail information to assess the functions inside the body. These images provide greater contrast between the different soft tissues of the body than other scanning technologies like computed tomography (CT) and X-rays. The magnetic resonance imaging scan is a non-invasive method that uses magnets and radio waves to give deep look inside the human body. It is widely used in the neurological treatment, musculoskeletal, cardiovascular, and oncological imaging. MRI does not use ionizing radiation like CT, but it uses powerful magnetic field to align the nuclear magnetization of hydrogen atoms in water that is present in the body. The MRI images can be reviewed on a large computer screen to identify the exact problem. Here radio frequency field is used to systematically alter the alignment of this magnetization, causing the hydrogen nuclei to produce a rotating magnetic field detectable by the scanner. A radiofrequency electromagnetic field makes the protons change their alignment relative to the field. As soon as the electromagnetic field is turned off, the released protons return to their original alignment.

What is a PET Scanner?

Positron Emission Tomography (PET) scans measure emissions from positron-emitting molecules. In the 1970s, PET scanning was introduced to the medical community. During the 1980s, the technology that underlies PET advanced greatly. Commercial PET scanners have resolution that is more precise and images that are more accurate than CT scanners. Many of the steps required for producing a PET scan are performed by a trained technician or an experienced physician, thereby reducing the cost and complexity of the procedure. The main difference between the CT and PET scans is the PET scan shows molecular function and activity instead of structure, and therefore can often differentiate between normal and abnormal tissue. A PET scan produces three dimensional images and usually compliments rather than replaces the information obtained from a CT scan. By measuring blood flow and metabolic rate within the heart, physicians using PET scans can discover areas of decreased blood flow, such as those areas with blockages, and differentiate living muscle from damaged muscle that has inadequate blood flow. This information is particularly important for patients who have had previous myocardial infarction or who are being considered for a procedure such as a coronary artery bypass surgery or angioplasty.