types of diagnostic imaging - medical interventions

what is an x ray used for?

• produce 2D images inside the body

• to help diagnose medical condiions

what is a CT used for

• produce images of the inside of the body

• to help diagnosed medical conditions

• 2D images can be reconstructed into 3D models

what is a MRI used for?

• produce cross sectional images of the inside of the body

• to help diagnose medical conditions

what is a Bone scan used for?

• produce images of the bones

• help diagnose and track several types of bone diseases

• produce2D images of the body

• detect skeletal abnormalities

what does X ray examine

1. bones

2. teeth

3. lungs

4. bre8ats

5. blood vessels

6. heart

7. di tract

8. hard tissues

what does CT examine

1. chest

2. abdomnen

3. pelvis

4. spine

5. other skeletal structures

6. hard and soft tissues

what does MRI examine

1. brain

2. spine

3. joints

4. abdomen

5. blood vessels

6. pelvis

7. soft tissues

what does bone scan examine

bones

how is an X ray done

a form of electromagnetic radiation, a machine sends photons through the body which results in images recorded on computer or special film

how is a CT scan done

• a series of X ray views taken from many diff angles combined to produce cross-sectional images of bone and soft tissues inside and outside the body

• performed inside of a large tube thats like a donut

• a person lies on a table in the center as the x-ray tube rotates around the body and moves slowly through the inside of the machine

• each rotation yields several images of thin slices of the body

how is an MRI done

• uses powerful magnets and radio waves instead of radiation

• performed inside a large magnet, a person lies on a table in the center

• the machine scans the body by turning small magnets on and off

• radio waves are sent into the body

• the machine receives returning radio waves and uses a computer to create photos of the part of the body being scanned

how is a bone scan done

• nuclear imaging test

• uses tiny amounts of radioactive materials called tracers (radionuclides)

• these tracers are injected, circulate, and are absorbed by bones

• once absorbed, the patient lies on a table which a machine passes a gamma camera over the body to record the pattern of tracer absorbed by the bones

• radiologists look for abnormal bone metabolism on the scan, areas that show up as lighter or darker where tracers have or have not accumulated

advantages for a x ray

• quick

• painless

• non-invasive

• relatively inexpensive

advantages for a CT scan

• painless

• noninvasive

• accurate

• fast

• simple

• able to image bone, soft tissue, and blood vessels simultaneously

• can be performed if the patient has an implanted medical device of any kind

advantages for an MRI

• noninvasive

• almost no safety risk when guidelines are followed

• does not involve exposure to ionizing radiation

• images of soft tissue structures are more likely to identify and accurately characterize diseases than other imaging methods (BEST for soft tissue)

• contrast materials sometimes used are less likely to produce an allergic reaction that those used in x-rays and CT scans

advantages for bone scans

• noninvasive

• extremely sensitive to abnormalities and variations in bone metabolism

• can scan the entire skeleton

disadvantages to x-rays

• use of ionizing radiation makes a small increase of risk for developing cancer (radiation exposure)

• contrast materials sometimes used may produce allergic reactions

disadvantages to CT scans

• use of ionizing radiation makes a small increase of risk for developing cancer (radiation exposure)

• contrast materials sometimes used may produce allergic reactions

disadvantages to MRI scans

• implanted medical devices that contain metal may malfunction or cause problems during an MRI exam

• very slight risk of an allergic reaction is contrast material is injected

• confined space may induce panic or feeling of claustrophobia in some patients

disadvantages to bone scan

• radiation exposure

how do structures that are dense and structures contained by air look on an x-ray

• structures that are dense will block most of the x-ray particles and appeal white (bone, metal, contrast media)

• structures containing air will appear black

• muscle, fat, and fluid will appear gray

what is a CT scan also called?

Computerized Axial Tomography (CAT Scan)