Dr. Tsubokura's Radiation Lecture Vol.15

Author: Masaharu Tsubokura

Editors: Akihiko Ozaki M.D., Yuki Senoo

29. Should we avoid radiation inspection?

Hospitals utilize a variety of imaging examinations, such as X-rays, CTs, MRIs, and ultrasounds, for diagnosis and treatment purposes.

X-rays and CT scanning sensitize the film with radiation whereas MRI creates images by using magnetic force produced in a tunnel made of strong magnets. As the name implies, in an ultrasound examination, ultrasounds are allied to organs, and the reflected waves are visualized. Principally, your body will not be exposed to ionizing radiation in MRIs and ultrasound examinations.

Therefore, you may think MRIs and ultrasound examinations are better examination methods because they do not use radiation.

However, this is not true.

These examinations differ from each other in the location of the body and diseases they can diagnose. Their availability and burden to our bodies are also different.Examination of the thyroid gland is performed by ultrasound whereas X-ray examination is performed in a bone fracture assessment.

The appropriate examination is selected depending on the examination’s concrete target.

30. Potassium is necessary for “life support”

Natural radioactive substances such as radioactive potassium are present in our body. All of our living cells contain potassium, which is necessary for us to live.

For example, they are used to control our nervous system functions. The amount of potassium in our body is strictly controlled to maintain a constant amount. Moreover, almost all kinds of food, such as vegetables, fruits, and meats, contain potassium.

However, not all potassium is radioactive. Several kinds of natural potassium called isotopes and 99% or more potassium are in a stable state and therefore do not emit radiation. The radioactive potassium, which frequently appears in the media, is one kind of potassium that accounts for a small proportion of all potassium.

Similarly, iodine, which also appears in the media to explain the effect of radiation on thyroid glands, is also essential for our body and has multiple types: normal iodine contained in food and radioactive iodine emitted in a nuclear accident. ---------------------------------------------------------------------------------------------------------------------------------------

The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, on July 26th and August 2nd 2015, and was reproduced for MRIC Global under the author's permission.