CT Final

The typical modern CT scanner generator converts: a) low-voltage AC to high-voltage DC. b) low-voltage DC to high-voltage DC. c) high-voltage DC to low-voltage DC. d) low-voltage DC to high-voltage AC.

a) low-voltage AC to high-voltage DC.

Scintillation detectors are associated with _____ patient dose and _____ image noise. a) lower; reduced b) higher; reduced c) lower; increased d) higher; increased

a) lower; reduced

Which of the following CT numbers represents water? a) 0 b) +1000 c) -1000 d) +3000

a) 0

Second generation scanning employed: a) a pencil beam/a single detector. b) a fan beam/multidetectors. c) more indexing (compared with first generation scanners) d) B and C are correct.

b) a fan beam/multidetectors.

Which of the following sources of radiation were used in Hounsfield's first primitive CT scanner? a) x-ray b) americium c) radium d) radon

b) americium

The window width (WW) determines the: a) image density. b) image contrast. c) voxel depth. d) voxel width.

b) image contrast.

Partial volume averaging can be improved by using: a) smaller pixel sizes. b) a smaller SFOV. c) thinner slice thicknesses. d) a larger DFOV.

c) thinner slice thicknesses.

Which of the following is not formed by the mesoderm? a) cardiac muscle b) kidneys c) dermis of the skin d) liver

d) liver

When image data is acquired by a CT scanner, it goes through a process known as: a) convolution. b) photon flux c) digitization. d) quantization.

d) quantization.

Absorption efficiency refers to how efficiently x-ray photons are captured by the detectors. True False

True

Human chorionic gonadotropin (HCG) is secreted by the: a) blastocyst b) zygote c) ovum. d) sperm.

a) blastocyst

Fourth generation scanners employed detectors that were: a) curved/nonrotating. b) linear/rotating c) curved/rotating. d) linear/nonrotating.

a) curved/nonrotating.

As postpatient collimation decreases, slice thickness: a) decreases. b) increases. c) remains the same.

a) decreases.

Sampling occurs at the: a) detectors. b) prepatient collimators. c) analog-to-digital converter (ADC). d) digital-to-analog converter (DAC).

a) detectors.

To view a CT image on a LCD monitor, data must undergo: a) digital-to-analog conversion. b) analog-to-digital conversion. c) digitization. d) quantization.

a) digital-to-analog conversion.

Which of the following types of scanners used water bags? a) first generation only b) first and second generation c) first, second and third generation d) Water bags have never been used with CT scanning.

a) first generation only

First generation scanners were only capable of imaging the: a) head/brain. b) extremities. c) chest, abdomen and pelvis. d) A and B are correct.

a) head/brain.

Which of the following is the most effective type of CT detector? a) scintillation b) xenon gas c) linear array d) photodiode

a) scintillation

Question 8. Question : Which of the following is not considered part of the ethmoid bone? a) superior nasal conchae middle nasal conchae inferior nasal conchae perpendicular plate

a) superior nasal conchae

Nutating refers to the process of: a) tilting the detector ring. b) tilting the x-ray tube. c) tilting the gantry. d) translation.

a) tilting the detector ring.

The _____ controls balance and equilibrium. a) vestibule and semicircular canals b) cochlea c) tympanic membrane d) ossicles

a) vestibule and semicircular canals

Which of the following are functions of the patient table? 1. contributes to patient safety 2. enhances subject contrast 3. transports the patient through the gantry a) 1 and 2 b) 1 and 3 c) 2 and 3 d) 1, 2 and 3

b) 1 and 3

Window level (WL) refers to: 1. the midpoint in a range of CT numbers. 2. image contrast. 3. image brightness. a) 1 and 2 b) 1 and 3 c) 2 and 3 d) 1, 2 and 3

b) 1 and 3

The arrow in this image points to what anatomical feature? a) Sphenoid sinus b) Maxillary sinus c) Ethmoid sinus d) Frontal sinus

b) Maxillary sinus

The z-axis refers to the ______ plane. a) coronal b) axial c) sagittal

b) axial

Beam-shaping filters are designed to: a) remove higher-energy photons from the beam. b) change the spatial distribution of the beam. c) decrease subject contrast. d) restrict the path of photons coming from the x-ray tube.

b) change the spatial distribution of the beam.

Which of the following x-ray beam geometries is used by modern, multidetector CT scanners? a) pencil beam b) cone beam c) fan beam d) pinpoint beam

b) cone beam

Which of the following structures connects the left and right hemispheres of the cerebrum? a) choroid plexus b) corpus callosum c) longitudinal fissure d) central sulcus

b) corpus callosum

As pitch increases, patient dose: a) increases b) decreases. c) is unaffected.

b) decreases.

Which of the following arteries supply blood to the face and scalp? a) internal carotids b) external carotids c) vertebrals d) cerebrals

b) external carotids

Compared with conventional (axial) CT scanning, spiral-helical CT has: a) longer interscan delays. b) faster imaging times. c) increased misregistration artifacts. d) B and C are correct.

b) faster imaging times.

First generation CT scanners used _____ beam scanning. a) cone b) pencil c) fan d) pinpoint

b) pencil

The cranial end of the neural tube separates into three primary vesicles. Which of these primary vesicles corresponds to the hindbrain? a) prosencephalon b) rhombencephalon c) mesencephalon d) vesencephalon

b) rhombencephalon

Which of the following results in better resolution? a) thick collimation b) thin collimation c) Collimation does not affect resolution.

b) thin collimation

Which generation of CT scanners was the first to use a curved array of rotating detectors? a) second b) third c) fourth d) fifth

b) third

Spatial resolution can be increased by using: 1. larger-size detectors. 2. a smaller pixel size. 3. thinner slice thicknesses. a) 1 and 2 b) 1 and 3 c) 2 and 3 d) 1, 2 and 3

c) 2 and 3

CT scanner x-ray tube voltages range from ______ to _____ kilovolts (kV). a) 60; 100 b) 80; 120 c) 80; 140 d) 100; 160

c) 80; 140

A CT gantry includes all of the following components except: a) collimators. b) detectors. c) central processing unit. d) bow tie filters.

c) central processing unit.

Which of the following terms refers to the posterior surface of the body? a) caudal b) ventral c) dorsal d) prone

c) dorsal

Which generation of CT scanners is associated with the term "EBCT" and the use of an electron beam gun? a) seventh b) sixth c) fifth d) fourth

c) fifth

Generators are often times located within the gantry. These types of generators are typically: a) full wave/three-phase. b) medium frequency. c) high frequency. d) multiwave/two-phase.

c) high frequency.

Spiral-helical scanners incorporate _____ slip rings. a) high-voltage b) low-voltage c) high- and low-voltage d) No choice is correct.

c) high- and low-voltage

With respect to detectors, the term "dynamic range" refers to: a) detector consistency. b) how efficiently the detectors gather the photons coming from the patient. c) the accuracy of response to both low- and high-energy radiation. d) No choice is correct.

c) the accuracy of response to both low- and high-energy radiation.

CT scanner x-ray tubes incorporate rotating anodes composed of: a) tungsten, copper and molybdenum. b) molybdenum, tungsten and rhodium c) tungsten, molybdenum and rhenium d) rhenium, tungsten and rhodium.

c) tungsten, molybdenum and rhenium

In sixth generation CT scanners, which of the following elements rotate around the patient? a) the x-ray tube b) detectors c) x-ray tube and detectors d) No choices are correct.

c) x-ray tube and detectors

With regard to human development, the embryonic stage lasts approximately _____ week(s). a) 1 b) 2 c) 4 d) 6

d) 6

The frontal sinuses are evident radiographically by age: a) 1 b) 3 c) 5. d) 7.

d) 7.

The term "translation" is associated with _____ generation scanners. a) first b) second c) third d) A and B are correct.

d) A and B are correct.

Beam-shaping filters are generally composed of: a) aluminum. b) copper. c) teflon. d) A and C are correct.

d) A and C are correct.

Which of the following terms is associated with seventh generation spiral-helical technology? a) multisection scanner b) multidetector scanner c) multiple detector array scanner d) All choices are correct.

d) All choices are correct.

Spiral-helical CT scanning is based on: a) sequential data acquisition. b) slip-ring technology. c) volume data acquisition. d) B and C are correct.

d) B and C are correct.

The scan field of view (SFOV) is determined by the: a) pitch. b) prepatient collimators. c) postpatient collimators. d) CT technologist before the scan begins.

d) CT technologist before the scan begins.

The process related to the first computed tomography scanner was called: a) computer-assisted tomography. b) reconstructive tomography. c) Hounsfield tomography. d) computerized transverse axial scanning.

d) computerized transverse axial scanning.

All power to the gantry of a spiral-helical CT scanner is conveyed via: a) high-tension cables. b) rotating wire brushes. c) photon flux. d) slip rings.

d) slip rings.

In multislice CT scanners, detector systems with equal-size detector elements are called _____ arrays. a) linear b) curved c) adaptive d) symmetric

d) symmetric

Modern CT scanners have x-ray tubes designed to withstand large amounts of heat. The anode on these tubes includes a target made of: a) molybdenum. b) copper. c) rhodium. d) tungsten.

d) tungsten.