Breast Imaging—Digital Mammography, Ultrasound, and Magnetic Resonance Imaging

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1

The range of values over which a digital system can respond, also known as the gray-scale range, is called what?

Dynamic range is the range of values over which a system can respond and is also known as the gray-scale range.

2

In digital imaging, which matrix of cells will have less information: a 5 × 5 or a 10 × 10?

A 5 × 5 image matrix of cells will have less information stored per cell than a 10 × 10 matrix of cells.

3

What is the name of the photoconductor used in direct digital systems?

Selenium (Se) is the common photoconductor used in direct flat-panel detector systems.

4

What is the name given to the device that replaces the film in the computed mammography systems?

Computed mammography uses a flexible imaging receptor (IR), also called a photostimulable storage phosphor (PSP) because it is coated with storage phosphors.

5

In digital imaging, name the process whereby a phosphor crystal will emit light when exposed to radiation.

Scintillation is the process by which certain materials scintillate or emit a flash of light in response to the absorption of ionization radiation.

6

Name two methods used to display the digital image.

Display methods include cathode ray tube (CRT), liquid crystal display (LCD), organic light-emitting diode display (OLED), and laser-printed film.

7

What is described as the biggest advantage of digital mammography?

The wide latitude of the digital signals

8

On what effect is the basic principle of ultrasound based?

Piezoelectric effect

9

Higher frequency ultrasound transducers have less penetration power. What feature makes them ideal for breast imaging?

They have greater resolution.

10

What is the effect of applying too much gain when imaging a simple cyst using ultrasound?

Artifactual echoes will be created, mimicking a malignant lesion.

11

Why is it is recommended that a lesion be imaged with and without a caliper in ultrasound?

To avoid obscuring the margins of the lesions

12

What information can ultrasound give about a cyst?

Rule out a malignancy or prove a benign lesion by showing that the cyst is fluid-filled versus solid

13

Describe the borders of a benign lesion.

Smooth

14

On ultrasound, if a lesion is irregularly shaped with spiculated margins, what is it likely to be?

Malignant

15

What type of lesion tends to show “posterior enhancement” on the ultrasound image?

Benign

16

What type of ultrasound lesion generally has spiculated margins?

Malignant

17

How many protons and electrons does the hydrogen atom have?

One of each

18

In MRI, how would you describe the wobble motion similar to the motion of a spinning top just before it falls?

Precession

19

In MRI, why is the primary magnet kept supercooled?

To ensure superconductivity

20

Identify the coil closest to the patient during an MRI examination.

Radiofrequency (RF) coil or RF probe

21

What action/s create/s the noise heard during the MRI examination?

The switching on and off of the gradient coils

22

In MRI, describe the relation of T1 to T2 in larger molecules, such as those found in fat.

Longer T1 and shorter T2

23

What describes the time interval between a 90-degree pulse and the measurement of the MRI signal?

Time to echo (TE)

24

Slice selection is determined by the selection of which coils in MRI?

Gradient coils

25

Give the term describing an imaging sequence using one RF excitation pulse at less than or equal to 90 degrees.

Gradient-echo pulse

26

How soon after injection of contrast are the MR images taken?

Within 5 minutes

27

What type of artifact is created if the part is outside the RF coil during MR scanning?

Aliasing artifact

28

Name two common benign disorders that can mimic malignancy on the MR image.

Fibroadenomas, inflammation, recent scarring, surgical scars, fibrocystic changes, active glandular tissue

29

What factor/s is/are associated with the single major risk during an MRI examination?

The magnetic properties of the MRI machine

30

Can a patient with an aneurysm clip have a breast MRI?

Yes. Not all clips have magnetic properties. The clip should first be checked for magnetic properties.

31

Give two uses of MRI of the breast.

Map tumor extent, screen dense breast, detect cancer reoccurrence, detect the spread of cancer, and assess the effects of chemotherapy or tamoxifen response, image implant to access leaks or rupture.

32

As pixel size decreases, the amount of data contained in the images will:

(A) Increase

(B) Remain the same

(C) Decrease

(D) Pixel size has no effect on image data

(A) Increase

33

In digital imaging, the dynamic range refers to:

(A) Range of intensities that are displayed

(B) Random background information that is detected but does not contribute to image quality

(C) Range of value over which a system can respond

(D) Layout of the cells in rows and columns

(C) Range of value over which a system can respond

34

The detector system in digital mammography is categorized as direct if:

(A) The x-rays are absorbed by the detector and an electrical signal is created in one step

(B) The x-rays are absorbed and converted to light, which is then detected by TFD

(C) The system has a wide dynamic range

(D) The spatial frequency is high

(A) The x-rays are absorbed by the detector and an electrical signal is created in one step

35

During the reading process, the light emitted from the PSP is collected by

(A) TFT

(B) CCD

(C) ADC

(D) PMT

(D) PMT

36

Most of the risks of MRI of the breast are associated with:

(A) The magnetic properties of the patient

(B) Ferromagnetic metals

(C) Technologist errors

(D) Radiologist error

(A) The magnetic properties of the patient

37

What is the name of the scintillator used in the flat-panel technology?

(A) Amorphous silicon

(B) Cesium iodide

(C) Amorphous selenium

(D) Thin-film transistor

(B) Cesium iodide

38

In MRI of the breast, a large value for the T1 or T2 will indicate:

(A) A long, gradual relaxation time

(B) A rapid relaxation time

(C) Hydrogen atoms are not aligned to the external magnetic field

(D) The RF field was not applied

(A) A long, gradual relaxation time

39

Sound waves cannot travel through:

(A) A medium

(B) Vacuum

(C) Gasses

(D) Liquids

(B) Vacuum

40

Typically, a lesion with no internal echoes, no spiculations, and fewer than four gentle lobulations would represent what type of lesion on ultrasound?

(A) Malignant

(B) Intermediate

(C) Carcinoma

(D) Benign

(D) Benign

41

The ultrasound transducer is used to:

(1) Convert electric energy to acoustic pulses

(2) Convert acoustic pulses to electric energy

(3) Change the speed of the sound waves

(A) 1 and 2 only

(B) 2 and 3 only

(C) 1 and 3 only

(D) 1, 2, and 3

(A) 1 and 2 only