✔✔phantom roi measures -987 it most likely represents what? - ✔✔air
✔✔Which of the following will serve to decrease the noise of a CT image - ✔✔decrease
matrix size
✔✔beam hardening - ✔✔The phenomenon whereby low-energy photons are absorbed
as the x-ray beam passes through an object, resulting in an increase in the average
photon energy of the beam. or
Beam hardening occurs as the x-ray beam traverses the patient. The x-ray beam used
in CT is composed of x-ray photons with numerous different energies. The
heterogeneous beam undergoes an increase in average photon energy as it passes
through the patient and the lower-energy photons are absorbed
✔✔ Circle of Willis (cerebral arterial circle) - ✔✔♣ R/L posterior cerebral arteries
♣ R/L posterior communicating arteries
♣ R/L internal carotid arteries
♣ R/L anterior cerebral arteries
♣ Anterior communicating artery
✔✔Circle of Willis (cerebral arterial circle) - ✔✔label diagram
✔✔Wrist - ✔✔know wrist bones/Never Lower Tilly's Pants Grandma Might come home
✔✔Brain Anatomy - ✔✔Brain Lobes
-Frontal
-Parietal
-Temporal
-Occipital
-Cerebellum
Brain stem
✔✔Brain Anatomy - ✔✔hindbrain, midbrain, fore brain
✔✔Brain Anatomy - ✔✔functions of each
✔✔CT IAC - ✔✔Refers to ears-internal auditory canal
✔✔PHOTON MEASUREMENT - ✔✔IT MUST ENTER DETECTOR CHAMBER, BE
ABDORBED BY DETECTOR MATERIAL, AND BE CONVERTED TO A MEASURABLE
EVENT
✔✔Name system that converts projection into proper digital form for array processor -
✔✔analog to digital convertor
, ✔✔PACS - ✔✔long term data storage, digital distribution of images, image display for
radiologists
✔✔CT system components - ✔✔Console, Host computer, Scan controller, DAC, High
voltage generator, Gantry control, Gantry, Amplifier, S&H, ADC, Array processor,
Storage device
✔✔CT Systems - ✔✔Systems are perfectly designed to get the results they get
✔✔A CT system manufacturer has a scanner in which the focal spot of the x-ray beam
can move to two, slightly separated, distinct locations. What benefit does the dual focal
spot provide compared to an identical scanner possessing a single focal spot?
1. the number of projections is doubled
2. the number of rays in a single projection is doubled
3. the patient dose is halved
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 & 3 - ✔✔
✔✔CT Systems - ✔✔All FALSE: Have no moving parts, cannot generate straight
coronal and sagittal image, limited to non-oblique transverse scanning
✔✔CT uses xrays why? - ✔✔they penetrate the body according to specific attenuation
characteristics of each tissue
✔✔Operators console - ✔✔is the key point of interaction between the technologist and
the imaging system
✔✔THE OPERATORS CONSOLE MAY INCLUDE - ✔✔1. MOITOR
2. KEYBOARD
3, GRAPHIC INPUT DEVICE
D. ALL THREE ARE USED TO PROVIDE THE TECH THE GREATEST FLEXIBILITY
IN SYSTEM OPEARION AS WELL AS EASE OF USE
✔✔CT Commands from tech - ✔✔received mostly by operators console
✔✔X-rays are produced when - ✔✔fast moving electrons collide with any kind of matter
because the electron loses kinetic energy which is converted into the emission of an x-
ray photon.
✔✔THE MA DETERMINES THE - ✔✔A. QUANTIFY OF XRAY PHOTONS