Rad Bio/ Rad protection Test 6 Ch.12/15

Explain how proper communication can reduce repeats

It alleviates much patient anxiety because of the exam is explained, the patient knows exactly what to expect and they have the opportunity to ask questions. This creates an environment in which the patient is more likely to cooperate and so repeats (due to motion or lack of cooperation) will be reduced

List the three main anatomical regions that should be shielded from the useful beam whenever possible

• eyes

• breasts

• gonads

List three things the R.T. can do to better protect every patient from unnecessary exposure to ionizing radiation

1. correctly ID the patient

2. check the doctors order

3. employ proper communication

4. collimate

5. use lead shielding

6. utilize correct positioning

7. utilize a proper technique

8. employ a high kVp and low mAs when possible

9. use intermittent fluoro

10. follow the department QA program (equipment and repeat analysis)

11. obtain proper hx before beginning the exam

How can a repeat analysis program reduce patient exposure?

When the R.T. is required to partake in a repeat analysis program, any areas requiring remediation will be quickly identified and proper education will take place so that improvements can be made in positioning or technique selection. In addition, if an R.T. knows they’re being evaluated, they are more likely to stay focused and “get it right the first time” which reduces repeats

Give two ways to reduce the likelihood of motion when radiographing a pediatric patient

1. proper communication

2. gentle but firm demeanor

3. proper immobilization

4. distraction methods

5. decrease exposure time

List the cardinal rules of radiation protection and explain how each should be applied

1. time (reduce time spent in the presence of an activated x-ray tube)

2. distance (increase physical distance from the source)

3. shielding (use PB shielding when necessary)

List three things the R.T. can do to reduce their own personal exposure to ionizing radiation

1. anything that will reduce patient dose

2. decrease the time spent exposed to radiation

3. increase the distance from the source

4. wear lead shielding as appropriate

5. stand at a right angles to the CR and patient when being in the room is unavoidable

6. Stay completely behind the control booth during the exposure

The following steps can be taken to assist a patient having difficulty holding a position for an exam: the R.T. can hold them, a nonpregnant female family member/ caretaker can hold them, a male family member/ caretaker can hold them, or mechanical immobilization can be used. Place these possibilities in the order they should be utilized.

1. mechanical immobilization

2. male family member/ caretaker

3. non-pregnant female family member/ caretaker

4. R.T.

If a person receives an absorbed dose of 5 Gy to 10% of their bone marrow, what is their mean marrow dose?

Absorbed dose X the % of bone marrow exposed

5 Gy x 10% = 0.5 Gy

If a given technique produces an exposure of 10 mR/hr at a distance of 2 feet from the beam, what will be the exposure at a distance of 1 foot from the beam?

Use the inverse square law to solve for new beam intensity at a new distance

Jane Doe, R.T. (R) is 62 years old. What is her lifetime effective dose limit?

Age in years X 10 mSv OR age in years X 1 rem

Flat contact shields

Most effective for non sterile AP recumbent positions and are placed directly over the patients gonads

Shadow shields

Suspended from the collimator box and used to provide gonad protection during sterile field procedures. Can’t be used with fluoro because there is no light field for guidance

Shaped contact shields

• Fir into a jock strap

• Pouch device and are used to encase the testicles of male patients. Not recommended for PA projections

Clear lead shields

A type of shadow shield that is transparent and is used for a full spine scoliosis survey; protecting both the breast region and the reproductive organ region

ESE (entrance skin exposure)

Most commonly reported because its the easiest to calculateS

Skin dose

Measured directly with a TLD to determine epidermis dose

Gonadal dose

The dose to the reproductive organs

Bone marrow dose

Also called the “mean marrow dose”; measures dose to the bone marrow

Workload (W)

The weekly radiation use of a diagnostic xray unit

Use factor (U)

The portion of beam on time that the xray beam is directed at a given barrier

Occupancy factor (T)

The fraction of the workweek in which there are people on the other side of a given barrier

Doses to the R.T. behind the control booth barrier must not exceed this amount

1 mSv (0.1 rem)

Control booth window barrier

1.5 mm Pb eq.

Protective eyeglasses

0.35 mm Pb eq.

Thyroid shield

0.5 mm Pb eq.

Annual EfD for the occupational worker

50 mSv (5 rem)

Annual EfD for the general public for continuous exposure

1 mSv (0.1 rem)An

Annual EfD for the general public for infrequent exposure

5 mSv (0.5 rem)

Cumulative EqD for the embryofetus during the entire gestational period

5 mSv (0.5 rem)

Monthly fetal dose limit

0.5 mSv (0.05 rem)

Annual EqD limit to localized areas of the skin and hands

<500 mSv (50 rem)

Maternity protective apron (front coverage only)

0.5 mmPb and 1 mm Pb eq.

Maternity protective apron (wrap around)

0.5 mm Pb eq.

Primary barrier

1/16th in Pb

Secondary barrier

1/32nd in Pb

Fluoro curtain

0.25 mm Pb eq.

Lead gloves

0.25 Pb eq.

Gonadal shield

1 mm Pb eq.

Clear lead shields

30 % Pb by weight

Bucky slot cover

0.25 mm Pb eq.

Portable exposure cord

6 feet

Recommended lead apron thickness

0.5 mm Pb eq.

What’s going to happen to your dose if you spend 2 seconds in an exam room during an exposure?

Your dose is going to double

What do we mean by total technique?

Refers to an IR exposure resulting from mAs and kVp

What is the first step in gonadal protection from ionizing radiation?

Collimation

What is the best way to control voluntary motion?

Communication

What is the single most effective tool we have as R.T.’s at our disposal to gain the patients trust and cooperation?

Communication