MRI / CT / PET scan technicians are radiological technicians who are specialised in the use of one of these diagnostic devices, which allows medical specialists to diagnose problems such as cancers, cardiovascular disease, infectious disease, appendicitis, trauma and musculoskeletal disorders.
CT, MRI and PET scans are all diagnostic tools which make it possible to ‘look inside’ the body without surgery. They are based on the fact that atoms in our bodies are altered when they absorb energy. Resonance refers to the level of absorption achieved by adjusting the frequency of the radiation and the strength of the magnetic field – like tuning a radio to a particular station.
CT (computerised tomography) combines special x-ray equipment with sophisticated computers to produce multiple images or pictures of the inside of the body. These cross-sectional images of the area being studied can then be examined on a computer monitor, printed or transferred to a CD.
The technician must be able to accurately interpret a medical specialist’s scanning instructions. The patient is positioned on the CT examination table, usually lying flat on their back or possibly on their side or stomach. Straps and pillows may be used to help maintain the correct position during the examination. If contrast material is used, which makes it easier to see abnormal tissue due to specific absorption rates, it would be swallowed, injected through an intravenous line (IV) or administered by enema, depending on the type of examination concerned. When the scans are complete, the technician needs to record the results and complete and maintain the patient’s files.
MRI (magnetic resonance imaging) uses strong magnetic fields and radio frequencies to create 3D images of both hard and soft tissue within the human body which aids the doctor in making a diagnosis. The task of an MRI technician are to interpret a medical doctor’s instructions, explain MRI procedures to patients, select software options and imaging parameters when adjusting an MRI machine, view images from an imaging session and keep records of the results. They also manoeuvre examination equipment, prepare patients for procedures, move disabled patients from wheelchairs onto examination tables and position them for imaging.
Positron Emission Tomography (PET) scans measure the amount of metabolic activity at a site in the body and a computer reassembles the signals into images. Cancer cells have higher metabolic rates than normal cells, so they show up as denser areas on a PET scan. PET is useful in diagnosing certain cardiovascular and neurological diseases because it highlights areas with increased, diminished or no metabolic activity, thereby pinpointing problems. PET can produce three-dimensional images and is usually used to complement rather than replace the information obtained from CT or MRI scans.
PET is often used in conjunction with an MRI or CT scan through “fusion” to give a full three-dimensional view of an organ and the location of cancer within that organ. The newest PET scanners are a combination of PET and CT devices that provide the important metabolic information from PET superimposed on the high-quality anatomic information from CT. The tasks of the technician are similar to those described above.
Employment opportunities for these technicians are steadily rising due to an increased need for qualified diagnostic imaging professionals in all areas of specialisation.
Schooling & School Subjects
Applicants for MRI / CT / PET technician programmes should typically already be completing their training as radiographers.
Degree: BRadiography (Radio Diagnostics) - UP, NMMU, UJ.
Diploma: N.Dip and B.Tech: Radiography - CUT, CPUT, DUT.
The duration of the course is 3 years. A fourth year will culminate in the BTech Radiography. Students can also complete the MTech and DTech degrees - UJ, NMMU.
Registration with the Health Professions Council of South Africa (HPCSA) is mandatory for this occupation. Consult the HPCSA website for the most up-to-date information relating to accredited qualifications and registration requirements. This information can be found in the relevant sections under the Professional Board for Radiography & Clinical Technology.
The Society of Radiographers of South Africa
Pinelands Business Park
New Mill Road
Tel: (021) 531-1231
Health Professions Council of South Africa (HPCSA)
(553) of Hamilton and
Tel: (012) 338-9300