Intro to Radiology Flashcards
What is the systemic approach?
History and physical examination -> ancillary test -> differential diagnosis -> final interpretation
This is an imaginary plane that divides the body into superior and inferior sections?
Axial plane (transverse)
Shows you left from right; anterior from posterior
This is an imaginary plane that divides the body into right and left sections
Sagital plane (lateral)
Shows you anterior from posterior; superior from inferior
This is an imaginary plane that divides the body into anterior and posterior sections?
Coronal plane
Shows you Right, left, superior and inferior
What are the terms used for conventional radiographs (or plane films)?
White structure have Increased density (radiopaque)
Black structures have decreased density (radiolucent)
What are the terms used for computed tomography (CT)?
White structures Increased attenuation; hyperdense
Black structures Decreased attenuation; hypodense
What are the terms used for magnetic resonance imaging (MRI)?
White Structure Increased signal intensity
Black structures Decreased signal intensity
What are the terms used for ultrasound (US)?
White structure hyperechoic
Black structure anechoic
Gray structure hypoechoic
What are the terms used for nuclear medicine?
White structure Increased tracer uptake
Black structure Decreased tracer uptake; photopenic
What are characteristics of x-rays?
form of electromagnetic radiation (EM) They create an image (rays completely penetrate) 2-D
How do you read an x ray in regards to color?
Air - black
Fat - blackish/gray
Soft tissue/fluid - gray
Bone/calcium - white/greyish (more white)
Metal (black, white, and shades of gray)
What are the characteristics of a CT?
- images are in slices Uses x-rays to obtain cross-sectional images 5 densities in exquisite detail Use oral and IV contrast Infection, neoplasm, hemorrhage, free air, etc. Limitations: radiation exposure, risk from IV contrast, expensive
How do you read a CT in regards to color?
Air- black
Fat- dark gray
Water/fluid- gray
Soft tissue- lighter gray
Bone- white
Metal- white/bright
What are characteristics of an US?
Uses ultra high-frequency sound waves to produce cross-sectional images in real- time
External and internal probes
1st line for peds and pregnant patient
Absces (free fluid in abdomen), fatty masses, peristaltic activity, vascularity/flow, etc.
Limitations: air/gas, bone, obesity and operator dependent.
How do you read an US in regards to color?
Water/fluid- black (This is very different from the other test because ultrasonic waves penetrate poorly through air and bone)
Soft tissues- shades gray
Fat- white
Which type of test can you use doppler flow with?
Ultrasound
What are characteristics of an MRI?
Uses a powerful magnetic field with radio frequency pulses to produce cross-sectional images
Magnetic properties of the “ hydrogen atom”
Excellent soft tissue contrast without ionizing radiation
Uses IV contrast
Neoplasm, infection, bleeds, etc.
What are the limitations of MRI?
calcifications; claustrophobia; internal metal objects (pacemaker, bullet, etc)
T1 and T2 refer to which type of test?
MRI
What is the difference between T1 and T2?
Water is dark on T1 and White on T2 Think WW2: Water is White on T2
What are characteristics of Nuclear medicine?
Uses gamma radiation to form images following the injection of various radiopharmaceuticals
Anatomical and functional information
PET (Positron Emission Tomography) and PET/CT fusion have revolutionized oncological imaging
What are limitations to Nuclear Medicine?
can be nonspecific; ionizing radiation
What are examples of special studies?
Fluoroscopy Image guided procedures
Mammography
DXA scan (dual-energy X-ray absorptiometry)
What is a fluoroscopy?
Viewing internal anatomy in “real-time” utilizing x-rays and “contrast”
What are different structures that are visually using fluoroscopy?
-esophagram -upper GI series -barium enema -myelogram -hysterosalpingogram -angiography
What is a mammography?
Special type of x-ray imaging to detail breast tissue Breast US, breast MRI, PET Screening vs. diagnostic mammogram Takes a cranial-caudal view and a mediolateral-oblique view
What is a DXA scan?
Utilizes low dose x-rays to measure bone mineral density. -To diagnose and follow osteoporosis -Calculate “T-score”* Normal bone: T-score greater than -1 Osteopenia: T-score between -1 and -2.5 Osteoporosis: T-score less than -2.5
What is PACS?
Picture Archiving and Communication System (stores digital images and allows viewing of images on a screen)
