Lesson 1

Question 1

This x-ray and gamma ray interaction is the predominant interaction in the diagnostic energy range with soft tissue

Answer 1

COMPTON SCATTERING

Question 2

Occurs when the binding energy exceeds the transferred energy with resultant ejection of electron

Answer 2

Ionization

Question 3

Maximum point of specific ionization beyond which a sharp drop is seen as the partial kinetic energy is exhausted and the charged particle is neutralized.

Answer 3

Bragg ionization peak

Question 4

Refers to the ability to detect very subtle changes in the grayscale and distinguish them from the noise image

Answer 4

CONTRAST RESOLUTION

Question 5

Tomographic counterpart of nuclear medicine planar imaging that provides a diagnostic functional information similar to nuclear planar examination. It uses a nuclear camera that records gamma ray emissions from the patient from a series of different angles

Answer 5

SPECT (Single Photon Emission Computed Tomography)

Question 6

Refers to the removal of photons from a beam of x-ray or gamma rays as it passes through matter.

Answer 6

ATTENUATION

Question 7

Defined by thickness of a material required to reduce the intensity of an x-ray or gamma ray beam to one half of its initial value

Answer 7

HVL (HALF VALUE LAYER)

Question 8

X-ray production efficiency exposure, quality and quantity are determined by 6 major factors which are:

Answer 8

1. Anode material
2. Tube voltage
3. Tube current
4. Beam filtration
5. Generator waveform
6. Exposure time

Question 9

Determines the maximum energy in the Bremsstrahlung spectrum and affects the quality of the output spectrum.

Answer 9

TUBE VOLTAGE (maximum energy)

Question 10

The following characterizes an antiscatter grid, except

Answer 10

1. Grid ratio
2. Grid frequency
3. Focal length

Question 11

Most common anode target material used in mammography x-ray tubes.

Answer 11

MOLYBDENUM

Question 12

Tube port window in mammography x-ray spectrum is made of:

Answer 12

BERYLLIUM

Question 13

Digital radiographic imaging that addresses major problems with conventional projection imaging where there is superimposition of overlying and underlying anatomy of the breast w/ pathology.

Answer 13

BREAST DIGITAL TOMOSYNTHESIS

Question 14

Mammography tube focal spot sizes

Answer 14

0.3 and 0.1 mm

Question 15

This factor affects both the spatial and contrast resolution in CT imaging

Answer 15

RECONSTRUCTION FILTER

Question 16

This CT artifact occurs when the CT voxels are large enough to encompass several types of tissue, such as bone and tissues from different organs.

Answer 16

PARTIAL VOLUME

Question 17

T2WI have:

Answer 17

Long TR; Long TE

Question 18

T1WI sequence

Answer 18

TE short, TR short, fat:bright

Question 19

This sequence detects alterations in the random (Brownian) motion of water molecules within tissues, measures diffusion and is used in detection of acute cerebral ischemia.

Answer 19

DWI

Question 20

MR artifact is a result of the mismapping of anatomy that lies outside of the field of view but within the slice volume. The anatomy is usually displaced to the opposite side of the image.

Answer 20

Wraparound artifacts

Question 21

This sequence reduces CSF signal and other water-bound anatomy in the MR image by using T1 selected at or near the bounce point of CSF to permit better eval of surrounding anatomy.

Answer 21

FLAIR

Question 22

Beam property where the sounds have a diverging profile

Answer 22

Fraunhofer zone

Question 23

Type of ultrasound interaction referring to the loss of intensity of the ultrasound beam from absorption and scattering in the medium.

Answer 23

ATTENUATION

Question 24

Distance between any two point that repeat on the sinusoidal wave of pressure amplitude.

Answer 24

WAVELENGTH

Question 25

This artifact arises from the 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.

Answer 25

REVERBERATION

Question 26

Greatest probability of malformation when radiation is received in peak differentiation occurs in which stage of gestational period.

Answer 26

ORGANOGENESIS

Question 27

Most commonly encountered tissue reaction (deterministic effect) following high dose image guided interventional procedures

Answer 27

SKIN DAMAGE

Question 28

Limit of exposure dose for occupational exposure of workers over the age of 18

Answer 28

Effective dose (ED) of 20mSv per year, over 5 consecutive years

Question 29

TRUE OR FALSE A "supervised" area is any area in which specific protection measures and safety provision are required for controlling normal exposures and limiting/preventing extent of potential exposures.

Answer 29

FALSE (Controlled area)

Question 30

Based on J. Bergonie and L. Tribondeau, cell radiosensitivity is affected by 3 factors, which are:

Answer 30

MITOTIC RATE DEGREE OF DIFFERENTIATION STAGE OF CELL CYCLE

Question 31

Hemorrhage appearance in MRI T1 , T2

Answer 31

Hyperacute : I (iso) Bleed (bright) Acute: I (iso) Die (dark) Early sub: Bleed (bright) Die (dark) Late sub: Bleed (bright) Bleed (bright) Chronic: Die (dark) Die (dark)

Question 32

Coils that simultaneously measure the signal from orthogonal views that have 2 separate amplifiers and gain controls

Answer 32

RF QUADRATE COILS

Question 33

Broadband RF Noise. A narrow band pattern of black and white alternating noise aka "zipper artifact"

Answer 33

Herringbone artifacts Compensation: Faraday cage

Question 34

Compensation methods for motion artifacts other than transposing PEG and FEG to relocate motion artifacts out of the region of diagnostic interest.

Answer 34

1. Cardiac and respiratory gating 2. Respiratory ordering of the phase encoding projections based on loc within respi cycle 3. Signal averaging 4. Short TE spin echo sequences 5. Gradient moment nulling 6. Presaturation pulses 7. Multiple redundant sampling