Past In-service Q Banks Flashcards
- Refers to imaging in which the energy source is outside the body on one side and the energy passes through the body and is detected on the other side of the body
A. Transmission imaging
B. Projection imaging
C. Fluoroscopic imaging
D. Mammographic imaging
A. Transmission imaging
Energy source is outside the body
The body on one side and the energy passes through the body and its detected on the other side of the body
Projection imaging each point on the image corresponds to information along a straight line through the patient
This is the most common imaging procedure in diagnostic radiology
A. Plain cranial ct
B. Full abdominal ultrasound
C. Chest x-ray
D. Plain cranial mri
C. Chest x-ray
Interaction of electromagnetic radiation may occur in several form and include the following
A. Scattering through change in trajectory
B. Absorption by removal of the radiation
C. Transformation into particulate radiation as energy to mass conversion
D. All of the above
D
The fraction of photons removed from a monoenergetic beam of x-rays or gamma rays per unit thickness of materials is called:
A. Linear attenuation coefficient
B. Mass attenuation coefficient
C. Mass energy transfer coefficient
D. Mass energy absorption coefficient
A
Typically expressed in units of inverse centimeters
It is the most basic measure of the resolution properties of an imaging system and perhaps most intuitive
A. Point spread function
B. Linear spread function
C. Edge spread function
D. Modulation transfer function
A
This is the reformatting of a volumetric data set into tomographic images by selecting pixel values from the data set that correspond to the desired tomographic image planes
A. Maximum intensity projection images
B. Multiplanar reformating
C. Volume rendering
D. Spatial filtering
B
Which is not correct regarding the production of x-rays
A. the x-ray tube insert contains the electron source and target within an evacuated glass or metal envelope
B. The tube housing provides protective radiation shielding and cools the x-ray tube insert
C. The x-ray generator supplies the voltage to accelerate the electrons
D. The x-ray beam filters define the size and shape of the x-ray field incident on the patient
D *collimators not the filters
Which of the following statements is not correct about heel effect?
A. Refers to a reduction in the x-ray beam intensity toward the anode side of the x-ray field
B. Caused by the greater attenuation of x-ray beam intensity toward the anode side of the x-ray field
C. More prominent with a longer source to image distance (SID)
D. Since the x-ray beam intensity is greater on the cathode side of the field, the orientation of the x-ray tube cathode over thicker parts of the patient can result in a better balance of x-ray photons transmitted through the patient and onto the image receptor.
C *last prominent with longer source to image distance (SID)
The output of an x-ray tube is often described by these terms except:
A. Quality describes the penetrability of an x-ray beam, with higher energy x-ray photons having a larger half value layer (HVL) and higher “quality”
B. QUANTITY REFERS TO THE NUMBER OF PHOTONS COMPRISING THE BEAM
C. Exposure is nearly proportional to the energy fluence of the x-ray beam
D. All of the above
D
The following are tools used for scatter reduction, EXCEPT:
A. Anti scatter grid
B. Air gap
C. Scan slot techniques
D. Bucky grid
D
Most common anode target material used in mammography x-ray tubes
Molybdenum
Breast compression is an important part of the mammography examination, whether using screen film or digital detectors. Which is not correct?
A. Firm compression reduces overlapping anatomy, decreases tissue thickness and reduces inadvertent motion of the breast
B. It results in fewer scattered x-rays less geometric blurring of anatomic structures and lower radiation those to the breast tissues
C. Achieving a uniform breast thickness increases exposure dynamic range
D. Allows the use of higher contrast film or allows more flexibility in image processing enhancement of the digital image
C *decreases exposure dynamic range
Many variables affect breast dose. Which is not correct?
A. The speed of the screen film receptor, the film OD and the digital detector SNR level are major factors
B. Breast thickness and tissue composition strongly affect x-ray absorption
C. Lower kv (lower HVL) increases beam penetrability (lower ESE and therefore lower ave glandular dose) but also decreases subject contrast
D. Anti scatter grids improve subject and radiographic contrast but increase radiation dose by the Bucky or digital technique compensation factor.
C higher kv —> Dec subject contrast
The following are correct about the modes of fluoroscopy, EXCEPT:
A. Continuous fluoroscopy produces a continuous x-ray beam typically using 0.5 to 6 ma
B. Variable frame rate pulsed fluoroscopy where the x-ray generator produces a series of short x-ray pulses
C. With pulsed fluoroscopy the exposure time ranges about 30 to 33 ms which reduces blurring from patient motion in the image
D. All modern fluoroscopy systems use a digital refresh memory where each image is captured digitally and is displayed continuously at the refresh rate of the fluoroscopy display monitor
C ( 3 to 10ms)
This is a standard feature on modern fluoroscopy systems and is achieved by continuously digitizing images in real time and temporarily storing them in a digital video frame memory
A. Road mapping
B. Mid sequence display
C. Last frame hold
D. Frame averaging
C
This is not correct about contrast and temporal resolution in fluoroscopy
A. The contrast resolution of fluoroscopy compared to radiography is low chiefly due to the low SNR
B. The anti scatter grid selectively removes contrast degrading scatter and preferentially allowed
C. The temporal resolution is relatively low in fluroscopy in comparison to radiography
D. All of the above
C
Temporal blurring is typically called image lag. Which of the following statements is not correct
A. Lag implies that a fraction of the image data from one frame carries over into the next frame
B. By blurring together several temporal frames of image data, a lower snr is realized, because the x-ray photons from the several images are combined
C. Contrast resolution in philosophy is essentially a measure of image noise
D. Whereas some log is usually beneficial for unrecorded fluoroscopic viewing, for recording dynamic events such as in digital subtraction angiography, lag is undesirable and recursive filtering modes are disabled
B. *higher SNR
Match the following
A. Worst image quality, higher radiation dose to patient
B. Worst image quality, higher radiation dose to patient
C. Better image quality, higher radiation dose to patient
D. Better image quality, lower radiation dose to the patient
- Increase in patient size
- Increase in source to skin distance
- Grid use
- A
- D
- C
What occurs distal to objects having very low ultrasound atenuation?
A. Shadowing
B. enhancement
C. Reverberation
D. refraction
B
What is a hypo intense signal area distal to an object or interface and is caused by objects with high attenuation or reflection of the incident beam without the return of echoes?
A. Shadowing
B. Enhancement
C. Reverberation
D. Refraction
A
What is this artifact that arises from multiple echoes generated between two closely spaced interfaces reflecting ultrasound energy back and forth during the acquisition of the signal and before the next pulse?
A. Shadowing
B. Enhancement
C. Reverberation
D. Refraction
C
What is this artifact caused by the variability of the speed of sound in different tissues?
A. Speed variability
B. Speed attenuation
C. Speed displacement
D. Speed alteration
C
What are the facts occur with multi element array transducers and result from the division of a smooth transducer surface into many small elements?
A. Grating lobes
B. Side lobes
C. Reverberation
D. Refraction
A
