Mosby Random Test 1 Flashcards
The process of scanning a phantom device of known density to improve the accuracy of CT attention measurement may be referred to as
calibration
after initiation of rapid bolus administration of an iodinated contrast agent, the hepatic venous phase of contrast enhancement occurs at approx ____
60-70 seconds
What are the 3 components of the uterine wall?
- perimetrium- outer layer of uterine wall
- myometrium- middle layer
- endometrium- innermost layer
The approx inherent filtration of the CT x-ray amounts to an aluminum equivalent of
3.0 mm
In a modern CT system, the total number of possible Hounsfield values that may be assigned to any one pixel is approx
4096
the degree of broadening, or point spread, that occurs along the z-axis during volumetric data acquisition
slice sensitivity profile (SSP)
What are the Agatston system ranges for coronary artery calcifications
minimal 1-10
mild 11-100
moderate 101-400
extensive >400
the systemβs ability to differentiate objects with similar densities is called
contrast resolution
during CT angiography, images may be reconstructed using only the greatest density encounter along each ray. this type of image is called a(n)
MIP
maximum intensity projections
Severe reactions to IV iodinated contrast material occur in approx __% of all PTs
less than 1%
In PTs who are right handed, the posterior descending artery branches from the
right coronary artery
the abdominal aorta divides into the left and right common iliac arteries at approx what level?
L4
What does MTF stand for?
Modulation transfer function
the mathematical method of quantifying the spatial resolution of a CT scanner is ______
Modulation transfer function
MTF
Stop-motion capability of a CT system is referred to as
temporal resolution
quantifies the CT systemβs ability to freeze motion and to provide an image free of blurring
temporal resolution
as a solid state CT detector measures transmitted radiation, it emits a proportional response in the form of a(n)
analog signal
examples of moderate adverse reactions to contrast are
severe vomiting, dyspnea, faintness, chest pain, and seizures
also known as intermediate
an abnormal connection between the intestine and an adjacent structure
fistula
two-dimensional representation a voxel
pixel
how do you calculate he dimensions of a voxel
pixel size X section width
term that refers to an excessive amount of nitrogenous materials in the blood and is a symptom of renal failure
azotemia
also known called uremia
the primary indication for CT perfusion of the brain is
acute stroke
ring artifacts are typically caused by
faulty detectors
the technique that provides the detail of the ouster potions of the 3D model while maintaining the typical CT detail of the lungs inside is called
surface rendering