Intro to Radiology Flashcards
The five most common imaging modalities in order from least to most expensive
Radiography
Ultrasound
CT
Nuclear medicine
MRI
Contrast used with MRI imaging used for neoplasms, infections, inflammation, or vasculature
Gadolinium
Which two imaging types are preferred in pregnancy?
Ultrasound
MRI
Is fat or water brighter in a T1 MRI?
Fat is brighter
Two common clinical indications for MRI with contrast of the CNS
Evaluate for primary and metastatic tumor
Differentiate active versus inactive lesions of MS
Which, planar or cross-sectional images, provide three dimensional images from two-dimensional slices?
Cross-sectional (CT, ultrasound, MRI)
Two common clinical indications for MRI with contrast of the musculoskeletal system
Osteomyelitis
Tumor characterization and assessment of disease extent
Wil movement of the object further to the x-ray machine (closer from the plate) provide a larger/smaller or fuzzier/sharper?
Smaller and sharper
Two strengths of MRI imaging
Superior soft-tissue contrast
Lack of ionizing radiation
Seven strengths of ultrasound
Widely available and cheap
Portable
Safe
Comfortable for patient
Real-time imaging
Good for seeing soft tissue
Doppler available to evaluate blood flow
Anatomic structures stacking on top of one another creating the appearance of increased density is an example of …
Superimposition
Does angiography provide a live or static image?
Static image
Which, planar or cross-sectional images, compress a large amount of information into a two-dimensional image?
Planar (C-XRs, mammography)
Which image plane looks through the body from a top down position?
Axial/transverse
One common clinical indication for MRI with contrast of the heart
Characterization of cardiac masses
Which, a CT or x-ray, gives a patient more radiation?
CT
Strengths (3) of CT scanning
Speed
Higher contrast resolution
Ability to manipulate image in post-processing on computers
Three weaknesses of MRI
Cost
Time
Can’t use with metal
Two types of nuclear imaging
PET (positron emission tomography)
SPECT (single photon emission tomography)
Is an x-ray with enhanced soft tissue visibility more likely to be over-penetrated or under-penetrated?
Under-penetrated
One common clinical indication for MRI with contrast of the abdomen/pelvis
Detection and characterization of mass lesions in the liver, kidneys, adrenal glands, pancreas, bowel, urinary collecting system, uterus and adnexa, and prostate
Increased slice thickness in a CT image may lead to this undesirable effect
Partial volume artifact
(aka volume averaging or slice thickness artifact)
Two weaknesses of ultrasound
Dependent on operator skill
Limited evaluation of deep structures, doesn’t work in obese
Three strengths of nuclear imaging
Provides information that’s unattainable in other procedures (function)
PET scans can tell whether tumors are malignant or benign, preventing surgery
Have the ability to detect diseases in their earliest stages
Is fat or water brighter in a T2 MRI?
Water is brighter
Two weaknesses of nuclear imaging
Radiation
Cost and accessibility
Weaknesses (2) of CT scanning
Radiation exposure
Nephrotoxicity from contrast materials
At what size does a small bowel dilation become a concern?
> 3cm
Which image plane looks through the body from a side on position?
Sagittal
An MRI image primarily reflects the ….. ……. in the patient
Water protons
Which imaging technique is a live-x-ray and what type of contrast is typically used with it?
Fluoroscopy
Used with barium contrast
Which image plane looks through the body from a front on position?
Coronal
Name the five basic densities in order from most to least dense
Metal
Bone (calcium)
Soft tissue (water, muscle)
Fat and lipid
Gas (air)
CT scanning should be limited in this patient population
Children
Do radiopaque objects appear black or white on x-rays?
White
Do radiolucent objects appear black or white on x-rays?
Black
Main disadvantage of plain radiography
Collapse of complex three dimensional structures into a two dimensional image
Which, T1 or T2, is the most anatomical MRI image?
T1
Which, T1 or T2, is the most commonly used and pathologic MRI image?
T2
Which imaging types give zero radiation to the patient?
Ultrasound
MRI
One common clinical indication for MRI with contrast of the breast
Cancer detection for patients undergoing screening and those with symptoms
Silhouette Sign refers to …
Loss of normal borders between structures
Due to two objects of the same radiographic density touching each other
Impossible to tell where one object ends and the other begins
Absolute first first first step when looking at imaging
Always look for the patient’s name and/or number
Low dose CT is acceptable at this point in pregnancy
After first trimester
Contraindications for use of radiographic contrast
Prior reactions or shellfish/iodine allergy
Pregnancy
Renal disease
Hematologic parameters (bleeders)
Radiographic density of an object depends on these two things
Composition of material
Thickness
Is an x-ray with enhanced bone visibility more likely to be over-penetrated or under-penetrated?
Over-penetrated
Wil movement of the object closer to the x-ray machine (further from the plate) provide a larger/smaller or fuzzier/sharper?
Larger and fuzzier
