Unit 21: Medical Physics Applications
Health and Safety in the medical use of ionising and non-ionising radiation technologies.
Introduction
All types of imaging techniques have their own risks, side effects and limitations. Although non-
ionising radiation techniques do not use radiation, they often use large amounts of energy to take
images of the body, which could lead to the body parts to be damaged such as the nervous system.
Alternatively, a known risk of ionising radiation technology is that it can lead to tumour or cancer if
the exposure is too high.
Health & Safety Risks, Limitations and Side Effects of Non-Ionising Radiation Imaging Techniques
There are no known risks from the sound waves involved in ultrasound as there is no exposure to
radiation. However, there are several limitations and side effects that are caused by it. For example,
when an internal ultrasound scan is carried out, which consists of passing a small ultrasound probe
with a sterile cover into the vagina or rectum, the patient may feel discomfort and pain. Similarly,
when an endoscopic ultrasound scan is carried out, a long, thin, flexible tube is inserted into the
patient’s body through their mouth that can be uncomfortable, which is why patients who need to
undergo an endoscopic ultrasound are usually given painkillers and sedatives to reduce the
discomfort they’d feel. In addition to this, when patients carry out certain ultrasound scans, they are
required to drink abundant water prior to the scan as they would be required to have lots of water to
fill their bladder as well as avoiding eating. This is done so that the bladded, which would be filled
with water, would move the bowel out of the way and allow the uterus to be pushed back to allow
the uterus, ovaries, babies, and cervix to be visualised in more depth and any complications to be
identified more easily.
There are health and safety risks posed by MRI. For example, individuals who have had implants such
as pacemakers implanted into the body previously cannot undergo an MRI because implants often
include ferromagnetic objects. When MRI is carried out, the strong magnetic field can attract the
ferromagnetic objects in the implant causing the implant to move leading to the patient to possibly
die. Another example of a health and safety risk of MRI is that gadolinium contrast is often used to
improve the image quality by making it clearer. However, gadolinium contract can cause side effects
to patients who have kidney problems, which is why a test called creatinine is carried out before an
MRI to see if a patient’s kidneys would be able to endure the use of gadolinium contract as otherwise
another type of imaging technique would be needed to be used. Additionally, limitations that often
lead to side effects of MRI include how it is quite noisy, which is due to the expanding of the coils
when the switching of the current is taking place as current is sent through a coiled wire
electromagnet. This limitation has led to a few patients to have hearing loss as well as a ringing
sound in the ear. Patients can be claustrophobic in tunnel, which is why they feel quite discomforted
while carrying out an MRI. This is why MRI is designed to have special lighting, ventilation, and
openings at both ends to reduce the patients from feeling claustrophobic.
Health & Safety Risks, Limitations and Side Effects of Ionising Radiation Imaging Techniques
All types of imaging techniques that involve ionising radiation have a health and safety risk of
developing cancer. This is because, ionising radiation is a type of radiation that can cause damage to
the DNA and healthy cells if it isn't used appropriately when needed in large quantities. A health and
safety risk of X-ray, which is a type of ionising radiation imaging technique, is that even though a
small dose of radiation is used, it still increases the possibility of an individual developing cancer later
