Download Radiology Chapter 1 | MED - Radiographic Pathology and more Quizzes Radiography in PDF only on Docsity!
Who produced and detected the first
electromagnetic radiation (X-ray)?
Wilhem Conrad Rontgen TERM 2
What are X-rays?
DEFINITION 2 Ionized electromagnetic (EM) radiation that has shorter wavelengths than visible light TERM 3
Soft X-rays are closer to what?
DEFINITION 3 UV light wavelength TERM 4
Hard x-rays are closer to what?
DEFINITION 4 gamma wavelength TERM 5
How are x-rays measured?
DEFINITION 5 roentgens (R)the rad (radiation absorbed dose)the rem (rad equivalent man)and curie (Ci)
1 roentgen equals what?
1 rad = 1 rem TERM 7
What does the curie measure?
DEFINITION 7 nuclear decay per second in a sample of radionuclide (1/ life) TERM 8
What is the correct name for an X-ray?
DEFINITION 8 a radiograph TERM 9
What is a radiograph?
DEFINITION 9 an x-ray film containing an image of part of a patients anatomy TERM 10
What is the difference between a radiologist
and a radiographer?
DEFINITION 10 Radiologists are physicians that train and subspecialize in different types of imaging. Radiographers are the technicians trained to perform specific types of imaging.
Why are 2 films needed to localize a
lesion?
Radiographs produce 2 dimension, planar images so at least 2 films (anterior-posterior called AP, and lateral) are needed to localize the lesion TERM 17
What are the basic components of x-ray
technology?
DEFINITION 17 x-ray tube and image receptor TERM 18
The production of X-rays requires what 3
things?
DEFINITION 18 source of electrons force to move them rapidly something to stop that movement rapidly TERM 19
Describe the x-ray tube
DEFINITION 19 has a cathode (negative terminal) and an anode (positive terminal) enclosed in a vacuum glass tube TERM 20
Describe how x-rays are created?
DEFINITION 20 The cathode has a heated thoriated tungsten filament that makes the electrons when kilovoltage is applied.The electrons strike the anode and decelerate creating the x-rays due to energy conversion.
What happens to x-rays produced in the
tube?
they are beamed though a series of lead shutters and travel out of the tube through a collimator (which controls the size of the projection area). At this point, beam of x-ray photons called primary radiation. TERM 22
Descreibe how the x-ray gets to the patient
DEFINITION 22 radiographer uses a light source on collimator to project representation of the x-ray field onto pt.cross hairs on light source help define position of central ray which is area of focus and pt is exposed to x-ray beam TERM 23
Describe what happens to the x-ray beam
after is hits the pt?
DEFINITION 23 primary beam passes through pt and undergoes attenuation (decreased number x-ray photons in beam)the beam loses energy due to scatter or absorption TERM 24
How is the image made?
DEFINITION 24 x-ray beam emerges from pt (remnant radiation) and contains an aerial image of the ptremnant beam intercepted by interpretation device called image receptor (latent image -- must be developed)latent image processed to become radiograph TERM 25
what are the 3 major classifications of
diagnostic radiographic imaging?
DEFINITION 25 film/screen radiographyfluoroscopic imagingdigital imaging
Relationship between radiodensity and
radiographic density
inverse relationshipgreater radiodensity = less radiographic density = whiter imageless radiodensity = greater radiographic density = blacker image TERM 32
Radiolucent
DEFINITION 32 Anything that lets x-rays pass tumors infections osteoporotic bone these images are made visible with contrast medium TERM 33
Radiopaque
DEFINITION 33 Anything that blocks x-rays metals like implants calcified gallstones TERM 34
Radiodense
DEFINITION 34 In modern medicine, radiodense substances of the body are those that will not allow X-rays or radiation to pass. TERM 35
What are the 2 types of radiodensity?
DEFINITION 35 radiographic film object patient
Describe the order of increasing object
radiodensity
air fat water bone metal TERM 37
Describe the order of increasing radiographic
density
DEFINITION 37 metal bone water fat air TERM 38
Describe contrast media
DEFINITION 38 radiopaque -- solid whitebarium sulfatepositive contrast media TERM 39
Radiodensity as a function of thickness
DEFINITION 39 The thicker an object is, the more x-rays it will absorbthe radiographic image gets lighter as the object gets thicker. TERM 40
Describe the relationship between
radiographic density and the radiograph
DEFINITION 40 Radiographic density means the amount of darkness ON THE FILM (the radiograph)
lower kVp = what?
The lower the kVp, the more variation in x-rays absorption, the more difference in how the image shows up (contrast) TERM 47
relationship between mA's and kVp
DEFINITION 47 inversehigher kVp means less mA's needed TERM 48
Rule of thumb regarding kVp and mA's
DEFINITION 48 highest kVp (force) and lowest mAs (time exposed to the radiation) to get a good film is the best method. TERM 49
Recorded detail
DEFINITION 49 the sharpness, resolution, definition of the shape.Motion, distance from the tube, and beam size affect detail. TERM 50
Radiographic distortion
DEFINITION 50 difference between the patient object being filmed and the recorded image.This is affected by distances from the tube, alignment of the patient, position of the ray
Number of images needed to view all 3-D of a
structure
At least two images, as close to 90 degrees to each other as possible TERM 52
Routine radiographic exam
DEFINITION 52 evaluates a body segment via a standardized selection of positions and projections chosen to provide the greatest visualization with minimal radiation exposure and are most commonly:APLateralOblique (wrist, elbow, ankle, hand) TERM 53
Components of a "view" (AP OR PA)
DEFINITION 53 first letter = first place central ray hits ptsecond letter = tells where x-ray left pts body TERM 54
What is "position"?
DEFINITION 54 Refers to the patients position and there are two ways this term is used: The patients general position: standing, seated, supine, prone, erect, recumbent, Trendelenburg Which body part is closest to the image receptor (Bucky) TERM 55
Decubitus
DEFINITION 55 specifically used to describe the pt in a horizontal position AND a horizontal x-ray beam.It is used to view fluid/air levels in the chest and abdomen.
the posterior oblique views what?
oblique views the contralateral (opposite) sideRPO = the left IVF TERM 62
How are radiographs analyzed?
DEFINITION 62 on view boxes, aka illuminatorsHot lights are used to focus attention on some areasDigital images are viewed on a LCD monitor. TERM 63
General rules of clarity of film
DEFINITION 63 the bony structure that is at a 90-degree angle to the x-ray tube will appear the most clearly defined and least distorted, whereas the more a bone is angled from the beam, the more it becomes distorted.the closer the structure is to the film plate/receptor, the less distortion and greater definition will be perceived TERM 64
Loss of image clarity or sharpness can be
related to what?
DEFINITION 64 can also be related to density and contrast (not using the best combination of exposure time and energy). TERM 65
Standardization
DEFINITION 65 Radiographers always strive to maximize consistency through the orientation of the structure to be exposed, the orientation of the x- ray tube, the position of the film, and standardizing distances (usually 40 inches for most radiographs, but with laterals of the C- spine & chest, & P-A chest it is 72 inches) to enable the peak kilovoltage and exposure times then to be relatively consistent
How are x-rays oriented when viewing?
the film is placed on a view box or the digital image is oriented on the monitor as if the person were in the anatomic position (facing toward the reader) except for the hand and foot which are normally placed with the digits and toes directed upward in a P-A view. TERM 67
Advantages of radiology
DEFINITION 67 quick, easy, portable, and relatively inexpensive TERM 68
Disadvantages of radiology
DEFINITION 68 : ionizing radiation, poor at visualizing soft tissues and small fractures.
