Radiology Flashcards
Exam radiation doses
CXR 10 Mammogram 42 X-ray abdomen 700 Upper GI 600 Chest CT 700 Bone scan 630 Nuclear cardiac perfusion 4070 Ultrasound 0 MRI 0
Radiopaque
Not allowing the passage of x-rays (more white)
Uses bone and metal as a reference
Radiolucent
Allows the passage of x-rays (more black)
Use air as a reference (BLACK)
X-rays how they work
Short wavelength
The shorter the wavelength the greater the energy
Inonizing radiation
Photons
Attenuation
The greater the density of tissues the greater the absorption of the X-ray
Factors That can affect image quality
Motion Thickness of the body part Scatter (intensity of the x-ray beam) Magnification Distortion
AP vs PA x-ray
An AP chest x-ray has the machine in the front and the x-ray film in the back. this makes the heart look larger.
this can lead to a misdiagnosis of cardiomegaly
Fluoroscopy
Moving/real time x-rays
Upper GI series are generally used to rule out?
Ulcers
GERD
Polyps
Dysphagia
Motality
CAT (CT) scan
Computer Assisted Tomography
Useful for the evaluation of soft tissue and bone as compared to plain x-rays
CT techniques
Bone windows Lung windows Venous phase acquisition IV contrast Oral contrast
MRI
Magnetic resonance imaging
Good for imaging soft tissue such as the brain, spinal cord, mascles, tendons, ligaments
Can use gadolinium as contrast
MRI weighting
T1-non, T1-gad, T2
T1 good for fatty tissue, contrast imaging
T2 good for edema and revealing white lesions on the liver
Ultrasound
Converts electrical energy to a brief pulse of high-frequency sound energy that is transmitted into patient tissues.
No radiation
Hyperechoic
Increased amplitude of Ultrasound waves returned. Typical of bone and dense tumor tissue “White spots”
