Overview of Medical Equipment Using Ionizing Radiation in Nigeria

Abstract

OVERVIEW OF MEDICAL EQUIPMENT USING IONIZING RADIATION IN NIGERIA The last decade of the 19th century could be said to have been the golden age of X-rays particularly with the use of ionizing radiation in the medical field which can be traced to three important discoveries namely; the discovery of X-rays by Wilhelm Roentgen in 1895, Natural radioactivity by Henri Becquerel in 1896, the discovery of Radium-226 by Pierre and Marie Curie in 1898. In 1913, Coolidge designed a “hot cathode” X-ray tube and his design is still in use today. In the first fifty years of radiation medicine, the technological progress was aimed mainly towards the area of development of analog imaging techniques, optimization of image quality with concurrent minimization of dose and ever increasing energies and beam intensities. The developments of the past two decades are germane to the integration of computers in imaging, development of digital imaging techniques and incorporation of computers into therapeutic dose delivery with high energy linear accelerators (Linacs). The typical energy range of clinical X-ray beams lie between 10 kVp and 50 MV and are produced in X-ray targets when electrons with kinetic energies between 10 keV and 50 MeV strike special metallic targets. Inside the targets most of the electron’s kinetic energy is transformed into heat and a small fraction of the kinetic energy is emitted in the form of X-ray Photons which are categorized into two types; the Characteristic X-rays (following electron - orbital electron interactions) and Bremsstrahlung photons (following electron - nucleus interactions). X-ray tubes majorly are of two types the Cathode and Anode X-ray tubes. A general X-ray unit has a tube assembly, a Bucky, a couch and an X-ray shield. X-ray units can also be classified according to their mobility (mobile x-ray assembly or by the patients posture (standing X-ray assembly),there also exists other types or X-ray classifications such as the computed tomography(CT) unit, Fluoroscopy machine, Dental X-ray machines, Mammography equipment and Angiography machine. X-rays can also be classified according to the number of gamma cameras, the types which fall under this category are the single headed Gamma camera, the double headed Gamma Camera, and the Triple headed Gamma camera. Furthermore, there are external beam Radiotherapy equipments which are considered as standard in modern radiotherapy. Under X-ray machines we have the superficial x-ray machine (50-80kVp) and the Orthovoltage x-ray machine (80-350kVp). There is also the Cobalt-60 teletherapy machine and the Linear accelerator (linac) which includes the specification types of Megavoltage x rays (6-25 MV) and Electrons (6-30 MeV).

Seminar presented by Abdullahi Hassan