Ct Tutor Exam 3 Wrong answers Flashcards
Which of the following is considered a non-ionic contrast material? 1. iodamide 2. iohexol 3. iothalamate 4. diatrizoate
2
the percent of total available x-rays that actually enter the detector chamber.
capture efficiency
The focal spot size is a geometric factor that influences___
spatial resolution
Contrast resolution is dependent on (4)
section(slice)width, algorithm selection, detector sensitivity, and noise
Which of the following will reduce the appearance of noise in the CT image? 1. Use of a wide window width 2. Increase in mAs 3. Increase in slice thickness
1,2, and 3 The appearance of noise in the CT image can be reduced by increasing mAs and increasing the slice thickness. Both of these cause an increase in the number of photons that penetrate the slice. The more photons the less noticeable noise will appear. The perception of noise is also decreased by using a wide window width.
the portion of the internal carotid artery as it enters the bony skull is called the carotid__?
siphon
number 5
ulna
the percent of x-rays entering the chamber which collides with the detector atoms.
absorption efficency
type of scan used in brain perfusion imaging:
dynamic
iopamidol (Isovue), Iohexol (Omnipaque), and iopromide (Ultravist)
non-ionic contrast
An acoustic neuroma (schwannoma) is formed from Schwann cells of the eighth cranial nerve (vestibulocochlear nerve). This type of cranial mass is best imaged with CT examinations of the:
internal auditory canals.
Corpus callosum
Falx cerebri
responsible for translating the commands into machine language and then sending each code to the appropriate system component.
The host computer
The commands from the technologist are most often received by the _______ of the computer.
System console
reconstructs images from the detector signals after they are sampled and digitized.
the array processor
The post-processing technique that would include only the bone tissue of a CT examination of the pelvis would be…
Thresholding
limiting the computer to include pixels with only a certain range of CT number values a three-dimensional model of a specific tissue can be rendered. This technique is called
thresholding.
Main pulmonary artery
The primary point of interaction between the operator and the rest of the imaging system is the
system console
reconstructs images from the detector signals after they are sampled and digitized.
The array processor
The major disadvantage of the early back-projection method of image reconstruction is the appearance of the
Star artifact
Scaphoid
The partial volume artifact is reduced with the use of a
smaller slice width
The production of the scatter radiation absorbed by the patient and detectors is caused by an interaction of the x-ray photon and matter, termed
Compton interaction
The diastolic pressure range for an adult is
60 – 80 mm Hg
Systolic pressure range for an adult is
110 – 140 mm Hg
Anterior cerebral artery
Non-ionic contrast media have an average osmolality of
750 mOsm/kg of water
A patient is positioned for a CT examination of the right foot. Which of the following accurately describes the position of the patient?
Supine with knees flexed and plantar surface of feet resting on the table
Splenic artery
Glenoid cavity
the source of the electron beam
The cathode filament
Ascending colon
What is the average range for activated partial thromboplastin time?
28 – 34 seconds
The aperture size determines the
slice or section thickness
Capitate
When the CT technologist selects the thickness of the slice the ___ is determined.
focal spot size
Internal carotid artery
Middle cerebral artery
Greater wing of sphenoid
an infant’s pulse rate averages between
100 to 180 BPM.
A child pulse rate is between
80 and 120 BPM
An adult pulse rate averages between
70 to 100 BPM.
Hamate
The cause of the cupping artifact is?
The tissues of the body attenuate low energy photons.
