Reference no: EM133111574

Task - Case Studies

1 Compare and contrast the uses and relative advantages of X-rays, ultrasound, gamma camera and MRI in examining internal structures.

2 Evaluate the hazards of X-rays, ultrasound, gamma camera and magnetic resonance in medical imaging and explain the control methods used to minimize risk to patients and operating staff.

You are provided with information describing safety procedures used in 3 medical imaging departments. For each department
a) explain the nature of the hazards to patients and staff
b) explain how the procedures reduce the hazardous effect

Explain the circumstances where each method of imaging might be used in preference to ultrasound, which has relatively low levels of hazard.

Scenario 1: Nuclear Medicine Imaging

• Patients who have had radioactive substances administered to them may be treated as outpatients when radiation exposures caused to family members and other persons by the residual activity in these patients remain insignificant.
The following dose constraints shall be applied:
Family members of the patient
o Children (including unborn children) 1 mSv/treatment
o Adults (under 60 years of age) 3 mSv/treatment
o Adults (60 years of age and older) 15 mSv/treatment
o Other persons (members of the public)*) 0.3 mSv/year
• If it is possible that the dose constraints of family members or any other individuals might be exceeded, (e.g. because of a long journey, or if there are small children at home) the patient must remain in hospital until the residual activity in this patient has fallen sufficiently.
• Patients who have received radionuclide therapy shall be accommodated in the hospital facilities in a manner that minimizes the radiation exposure of workers, other patients and visitors.
• After 131I treatment the patient may be released from hospital after receiving the relevant radiation protection instructions when the residual 131I activity in patient no longer exceeds 800 MBq.
• Patients should be able to use public transportation for journeys of no longer than two hours. Patients with incontinence should not be released to their own home or to nursing home immediately after treatment.
• When using beta-emitting radionuclides, such as 32P, 89Sr and 90Y, no radiation protection measures are necessary after the residual activity in a patient no longer exceeds 200 MBq.

Scenario 2: Hospital MRI scan
• Personnel must wear the standard clothing and footwear provided at all times.
• All jewellery must be removed before entering the facility.
• All personal effects must kept in lockers outside the facility.
• Health and safety checklist to be completed with all patients.
• Patients must be escorted into the facility by operating personnel.
• Patients must not be accompanied by friends or family.

Scenario 3: X ray imaging department

• All diagnostic examinations involving medical exposures are performed with the radiation dose to the patient being as low as reasonably practicable to achieve the required quality of image.
• All operating personnel must withdraw from the treatment area when X-ray tube is in operation.
• Personal dosimeters (film badge) should be worn on the front of the body, in the area of the main torso, anywhere from waist to neck. Individuals who wear lead garments should position the whole body dosimeter at the collar level, outside of any lead protection.
• When not wearing the dosimeter, it should be stored in an area away from any radiation sources.
• Do not lend your dosimeter to another person, and do not wear another person's dosimeter.
• Personal dosimeters must be submitted for analysis every 3 months.
• If your dosimeter is damaged or lost, promptly contact the badge coordinator or the Radiation Safety Office.
• Personnel must inform the Radiation Safety Office if they become pregnant or are intending to become pregnant.