Rad Anatomy Quiz 1 Flashcards
What type of sound waves does musculoskeletal ultrasound use?
High frequency
Reflected sound waves provide what kind of information?
Information about depth, type of tissue, and tissue interfaces
What are the 4 types of echogenicity that describe a tissue?
Hypoechoic (black), Anechoic, Hyperechoic (white), Isoechoic
What are the 4 significant advantages of US?
Availability, low cost, noninvasiveness, and lack of known harmful effects
What is MSK US mainly used for detecting?
Detects tears or hypertrophy in injured superficial soft tissues
What are the different types of advanced imaging?
Computed Tomography (CT) Magnetic Resonance Imaging (MRI) Myelography (w & w/o CT) Diagnostic Ultrasound Nuclear Medicine Dual Energy X-ray Absorptiometry (DEXA) Mammography
What are the 4 main advantages of MSK US?
High-resolution soft tissue imaging, ability to image in real-time, facilitates dynamic exam, interactive
Is MSK US affected my metallic artifacts?
Minimally affected by implants and hardware
What are the 6 main DISadvantages of MSK US?
Limited field of view, operator dependent, incomplete evaluation of bones and joints, lack of educational infrastructure, limited penetration, lack of certification
What are the 6 properties of x-rays?
Travel in straight lines at the speed of light, cause crystals to fluoresce, cannot be detected by human senses, undergo differential absorption, cannot be refracted by a lens, produce biological effects
What is the path of the x-ray beam?
From source, through subject, to the film
What are the 5 parts of image formation?
x-ray tube, x-ray beam, object, film, image
What does the x-ray tube do in image formation?
source of electrons
What is the x-ray beam?
focused stream of photons directed at object
When are x-ray photons produced?
when electrons hit the target
What is the most central portion of the x-ray beam called?
Central ray
What is absorption of the x-ray beam dependent on?
Penetration dependent on density. Denser object = less penetration
What color will the film be if there is more beam striking the film?
black
What color will the film be if less beam is striking the film?
whiter
What color is the film with more tissue quantity/increased tissue density
Whiter = more opaque
What color will the film be if there is less tissue quantity/decreased tissue density?
Darker = more lucent
Are there more or less photons coming out of bone muscle and air?
Bone (least photons out), muscles, air (most photons out)
In a glass tube, there is bone, fat, water, and air; what is their order from darkest to lightest?
Darkest: air (lungs, trachea), fat (fascial plane, perirenal fat), water (muscle/organs), bone + water (fillings, markers, ortho devices): Lightest
Does metal show up light or dark in an x-ray?
Light - opaque
Least dense tissue is referred to as what?
Radiolucent, more black
Most dense tissue is referred to as what?
Radiopaque, more white
Readily allowing x-rays to pass through the object to strike the film is known as:
Radiolucent (blacker)
Not permitting the transmission of x-rays through the object to the film is known as:
Radiopaque, white (metal more opaque than bone)
What does projection mean?
Orientation of beam to patient
What does position mean?
Orientation of patient to film/equipment
What are the 3 common projections?
Anteroposterior/posteroanterior, lateral, oblique
In AP/PA, how does the central ray enter the patient?
Front to back (AP), back to front (PA)
What plane does the central ray enter the patient in AP/PA?
Horizontal plane
In which projection does the x-ray beam enter the side of patient?
Lateral
In what plane does lateral projection occur?
Coronal (left to right, right to left)
What are the two options when naming lateral projection?
Left lateral, right lateral
During left lateral projection, which side of the patient is against the film?
Left side (beam travels from right to left)
In which projection is the patient positioned obliquely to the film?
Oblique, central ray passes through the patient at a 45 degree
In what plane does oblique projection occur?
45 degrees to their coronal and sagittal planes
What are the 4 options when naming oblique projections?
Right/Left Anterior Oblique, Right/Left Posterior Oblique - named for the body part that is against the film
What are the 4 different body positions?
Upright, recumbent, oblique, and decubitus
What are the minimum diagnostic series?
Minimal 2 views perpendicular to each other (90 degrees)
What are the standards for choice of positioning?
Place structures closest to film, patient’s clinical presentation, patient’s size, patient protection, differential diagnoses
What are informational markers?
Markers that provide info about the patient, the doctor/facility, side of patient/patient positioning
Mitchell Markers
Metal markers, taped to cassette, label anatomical side of patient (AP/PA), label side of patient closest to film (laterals/obliques)
What is in the middle of a mitchell marker?
BBs (lead), gravity dependent to depict orientation of the cassette when the x-ray is taken
What other info can markers show?
Type of study, patient positioning, technologist, facility
Can you identify which side of the patient is toward the film without a marker?
No
What does the name blocker contain?
Patient’s name, gender, age, Doctor’s name, facility, date of study
Composite shadowgram
representing the sum of the densities interposed between the beam source and the film
What is superimposition affected by?
The superimposition of objects is affected by their anatomical relationships in various planes
What is not affected by superimposition?
The order (AP vs PA) that the beam strikes the objects
What is projection and superimposition affected by?
The objects relationship to the central ray
Magnification equation
O (object) = I (image size) x CF (correction factor)
CF
D(total film distance) - d (object film distance) / D(total film distance)
Magnification of R & L articular pillars of cervical spine are how many cm from film?
R - 15 cm
L - 19 cm
What is TFD?
Total Film Distance = 72” (180cm)
What are the correction factors (CFs) for right and left magnification?
CFR - 180-15/180 = .916
1/.916 = 1.092 cm = image size
CFL - 180-19/180 = .894
1/.894 = 1.119 cm = image size (.027 mm smaller)
Collimation
Shutters (barn door) block peripheral portions of beam. Uses most central portion of beam
What does collimation do?
Limits size of x-ray beam field, use smallest area possible for good x-ray, decreases scatter radiation, decreases patient dose, achieves better detail, tube light simulates x-ray beam
Compact bone
Cortex: outer shell of bone, encloses the medullary bone, covered by periosteum, homogenous density on x-ray
Spongy bone/Cancellous Bone
The network of trabeculae in the medullary portion of the bone
Periosteum
Fibrous outer layer of bone, responsible for membranous bone formation, attachment of tendons and ligaments, contains vascular supplies for the bone
Is normal periosteum distinguishable on an x-ray?
No
Flat bones
ribs, sternum, scapula, cranium, iliac wing
Short/Square bones
carpals, tarsals, vertebrae
Sesamoid bones
embedded in tendons
Long/tubular bones
femur, humerus
What is the articular end of the long bone?
Epiphysis. Separated from the rest of the bone by the physis (growth plate)
What is the tapering portion between the physis and the shaft (diaphysis)?
Metaphysis. The site of growth and greatest metabolic activity
What is the shaft of the bone?
Diaphysis. Medullary cavity filled with red marrow
What are apophyses?
Tuberosities, tubercles, trochanters, processes, spines/spinouses (osseous projections from the general shap of the bone)
What are the ABCS of evaluation?
Alignment, Bone, Cartilage, Soft tissue
Alignment
Evaluate for spatial relationship structures, look for offset of articular margins, evaluate structures for proper position, measurements
Bone
Evaluate for shape, size, cortical integrity, internal matrix, radiographic density, specific structures
Cartilage
Evaluate for joint shape, joint size, radiographic density
Can cartilage be visualized on plain film?
No, it is represented by the space that it occupies
Soft tissues
Evaluate shape, size, position, radiographic density
What are the 5 steps of evaluation?
- Identify the study 2. Identify the informational markers 3. Note collimation, shielding, and artifacts Step 4. Note the technical quality of the film 5. Evaluate anatomy using ABCs search pattern
Step 1: The Study
Anatomy visualized, number of films, projections, use of contrast media
Step 2: Information
Name blocker, Qualification of study (position, type), timing of certain studies
Step 3: Collimation
Collimation, shielding, artifacts
Step 4: Film Quality
Diagnostic quality, proper positioning, entire area visualized
Step 5: Use search pattern
ABCs
