Chapter 1 - Premilinary Steps In Radiography Flashcards
Degree of film blackening
Optical Density
Primary factors controlling density are
mA
Exposure Time
mAs
Difference in density between two areas on a radiograph
Contrast
- A low contrast image displays many density levels and a high contrast image displays fewer density levels.
The primary controlling factor of radiographic contrast is
kVp
Ability to visualize small structures
Recorded Detail
Recorded detail is primarily controlled by the following
Geometry Film Screen Distance Focal Spot Size Motion
Primary controlling factor of Shape Distortion
Alignment CR Angulation Anatomic Part IR
Misrepresentation of the size or shape of any anatomic structure
Distortion
Is the process of killing only those microorganisms that are pathogenic
Disinfection
Chemical substances that inhibit the growth of without necessarily killing pathogenic microorganisms are called
Antisepsis
3 types of muscle tissue that affect motion
Smooth (Involuntary)
Cardiac (Involuntary)
Straited (Voluntary)
Primary method of reducing involuntary motion is by
Reducing exposure time
To prevent straining the back muscles when lifting a heavy patient, you should
Flex the knees, straigthen the back and bend from hips
When moving a patient’s hip, what should you do
Flex the patient’s knees to raise themselves or if not, raising the body is easier when the knee is flex.
How many person is preferable in transferring the patient to the radiographic table
At least four or preferably 6 persons
Restrictions of collimation serves what two purposes
- Reduce patient dose and reduces the amount of scatter radiation that reach the IR
- Excellent recorded detail and improve radiographic contrast, producing shorter scale contrast
Conditions that require a decrease in technical factors include the following
☑️ Old age ☑️ Emphysema ☑️ Pneumothorax ☑️ Emaciation ☑️ Degenerative Arthritis ☑️ Atrophy
Conditions require an increase in technical factors includes
☑️ Pneumonia ☑️ Pleural Effussion ☑️ Hydrocephalus ☑️ Enlarged heart ☑️ Ascites ☑️ Edema
Depresses the diaphragm and abdominal viscera
Lengthens and expand the lung fields
Elevates the sternum and pushes it anteriorly
Elevates the ribs and reduces their angle near spine
Inspiration (Inhalation)
Elevates the diaphragm and abdominal viscera
Shortens the lung fields
Depresses the sternum and lowers the ribs and increases their angle near spine
Expiration (Exhalation)
When exposure are to be made during shallow breathing, the patient should practice what
slow, even breathing so that only the structures above the one being examined move
When lung motion and not rib motion is desired, the patient should practice what
slow, deep breathing after compression band has been applied across chest
