Unit 1 (Preliminary Steps)

The device that receives the energy of the x-ray beam and forms the image of the body part

• Cassette with film
• Image Plate (cassette with phosphor plate)
• Fluoroscopic screen
• Direct Radiography (DR)
• (Solid-state detectors)

we will use them some in the lab, but not in the clinical hospitals. The cassette holds film you process in the dark room.

Also called a cassette with phosphor plate. This is used in CR (computerized radiography). The whole cassette goes into a reader which feeds the info to the computer monitor.

The image is formed and transmitted to a television monitor via a camera and is shot and viewed in "real time."

This created still images that are viewed on a computer screen, and they are digital, with no cassette.

• 8" x 10"
• 10" x 12"
• 11" x 14"
• 14" x 17"

Multiply inches x 2.54 to convert to cm

• 14" x 17"
• PA Chest, abdomen, etc.

• 10" x 12"
• hands, feet, etc.

The relationship of the anatomic superimposition to size, shape, position, and angulation must be reviewed.

Each anatomic structure must be compared with adjacent structures and reviewed to ensure that the structure is present and properly shown; varies from patient to patient.

The degree of Black/White

the difference in density between any two areas on a radiograph, must be sufficient to allow radiographic distinction of adjacent structures with different tissue densities; the shades of gray

• short contrast: more black/white, more penetration
• long contrast: more gray, less penetration

the ability to visualize small structures, must be sufficient to show clearly the desired anatomic part

this must be evaluated, sometimes it's desirable, sometimes not...many factors contribute to the level of magnification.

This can be caused by angling the tube in ways that distort the image. Distortion is defined as the misrepresentation of the size or shape of any anatomic structure.

The patient is standing, facing you with palms of the hands facing forward, feet slightly apart, toes facing forward.

as though the person looking at the image sees the body part in anatomic position

• Digits up for the following:
• hands
• wrist
• feet
• toes

laterals - in the direction patient was actually facing

in the position the patient was during the x-ray

a radiograph that is angled somewhere between a front shot and a back shot

anatomical position

• "eyeball" patient for obvious symptoms
• note anything that might affect radiograph (tattoo, scar, external mass, etc.)
• conversationally question the patient about their condition

NEVER, UNDER NO CIRCUMSTANCES

daily (at least), with a damp cloth (from top to bottom)

the floor

with alcohol or a dry cloth

after EACH patient, discarding ALL linens

treat EVERY patient as if they have a serious contagious illness (in terms of safety precautions)

treatment after an exposure has occured

1 part bleach to 10 parts water

kill only those microorganisms which are pathogenic (not their spores)

• inhibit the growth of pathogenic microorganisms (does not kill)
• ex. alcohol

the complete removal of microorganisms and their spores; necessary for any invasive procedures

as clean as reasonably possible short of complete sterilization

usually in every exam room

• what images should be taken for a procedure
• what equipment to use
• specific doctor preferences
• etc.

• voluntary
• involuntary

• motion that can be prevented or controlled by the patient (ex. breathing, moving extremities, etc)
• striated muscle (skeletal muscle)

• give clear breathing and position instructions
• provide for patient comfort
• use support and immobilization devices

• motion that the patient cannot control
• smooth muscle and cardiac muscle

• pain/fear
• muscle spasm
• tremors (trauma, shock)
• peristalsis (intestines)
• chill
• heart palpitations

by using the shortest exposure time possible (the quicker the exposure, the better chance of avoiding the movement)

• fixed
• floating

pulls our from underneath the table and includes a bucky-type moving grid

caliper (measure thickness in cm)

General position (ex. help the patient onto the table)

measure the part to be radiographed and set the control panel

• center the part to the CR (central ray)
• center the film to the CR

adjust collimation

correctly place the anatomical marker

gonadal shield placement

breathing instructions (as needed) to the patient

make the exposure

technique chart (also, exposure chart)

• age
• weight
• muscle tone
• congenital and developmental factors
• pathologic conditions

• inhalation
• breath in and hold breath
• moves diaphragm to its lowest point

• exhalation
• breath out and hold air out
• holds the diaphragm up

• two:
• patient id and date
• anatomic marker

only the type that is imprinted on the image from being placed on the cassette before the image is taken (the type that can't be moved/changed)

• never obscure anatomy
• never placed over patient identification marker
• always on the edge of the collimation field
• placed on outside of any lead shielding

• patient's name
• identification number (important for follow-ups; legal)
• institution identity
• date

• radiographer initials
• time indicators
• decub markers
• upright/erect markers
• inspiration/expiration
• internal/external

just large enough to cover the part imaged

• object-to-image distance
• a minimal OID; get as close to actual size as possible

• it should run with the long axis of the film
• ex. the forearm should run along the length, not the width of the cassette

• Central Ray: the central or principal beam of radiation
• Computerized Radiography: non-analog

to place the CR at right angles (90°) to the part being imaged

40" - 48"

• 72"
• true size of the part is essential to the diagnosis, so distance must be increased

it also increases

from the anode to the image receptor

it decreases

the SID must be LOWERED 1" for every 5 degrees the tube is angled

decrease

decrease

improve

shorter scale of contrast

• use if gonads lie within 5 cm of primary beam
• if pertinent anatomy will not be covered
• if the patient has a reasonable reproductive potential (9-90)

• shadow shielding
• contact shield
• large part area shields (lead aprons, etc.)

• projections commonly taken on all average patients who can cooperate fully
• usually a minimum of 2 projections, 90° apart

those who can walk in themselves and cooperate voluntarily

• usually necessary for patients who cannot cooperate fully
• usually only one projection due to patient difficulties

• AP chest
• AP abd
• AP pelvis

• to combat problems of anatomic structures being superimposed
• localizations of lesions or foreign bodies
• determination of alignment of fractures

• a minimum of three:
• AP/PA
• lateral
• oblique

hip joints are usually only two projections, instead of the normal three for a joint

check the exposure control index

90

more sensitive to scatter

• less sensitive
• takes 15-20 seconds to become exposed