Question 1

Interpolation results in a loss of image data.

Accepted Answer

Interpolation is the process of changing the matrix size after the image has been acquired. The matrix can be changed from a larger size to a smaller size, or from a smaller size to a larger size. When an image is interpolated, there is no loss of data. The data is redistributed from one pixel to the adjacent pixels. Because of the shifting of counts from one pixel to the next, smoothing (linear) should be applied to the image to ensure an even distribution of counts.

Question 2

Software magnification&#10;A) increases resolution.&#10;B) decreases noise.&#10;C) only increases image size.&#10;D) increases sensitivity.

Accepted Answer

Magnification of areas on digitized images can also be performed. Most commonly, magnification (software zoom) is used to improve the visual display, though there is no increase in resolution.

Question 3

On a computer, image resolution&#10;A) deteriorates as the acquisition matrix size increases.&#10;B) deteriorates as the acquisition matrix size decreases.&#10;C) remains consistent across matrix size for a given camera.&#10;D) remains consistent across matrices if pixel rollover is controlled.

Accepted Answer

The image resolution deteriorates as the selected acquisition matrix size gets smaller.

Question 4

When using temporal smoothing&#10;A) noise is removed without loss of spatial resolution.&#10;B) noise is removed with a slight loss of spatial resolution.&#10;C) noise is not removed, but there is a slight increase in spatial resolution.&#10;D) results are the same as nine-point image smoothing except it is applied to dynamic studies.

Accepted Answer

Temporal filtering is applied most frequently to gated cardiac images with the filter applied in a closed loop. Temporal filtering removes noise without a loss of spatial resolution as occurs with the nine-point smoothing.

Question 5

In an 8-bit color image, the range of displayed color intensities would be&#10;A) 0 to 64.&#10;B) 0 to 100.&#10;C) 0 to 128.&#10;D) 0 to 255.

Accepted Answer

Although the human eye can differentiate fewer than 100 shades of gray, most computer systems generate an 8-bit image, assigning display intensities from 0 to 255.

Question 6

The quality of the cardiac data during a MUGA can be compromised by&#10;A) breathing.&#10;B) bradycardia.&#10;C) tachycardia.&#10;D) PVCs.

Accepted Answer

In patients with arrhythmias, the quality of the data is compromised by premature ventricular contractions (PVCs) and the compensatory beats that follow PVCs.

Question 7

Hardware magnification or zoom&#10;A) decreases resolution.&#10;B) increases noise.&#10;C) only increases image size.&#10;D) increases sensitivity.

Accepted Answer

Although zooming increases resolution, there is a decrease in the number of counts per pixel, resulting in a noisier image.

Question 8

When using list mode to acquire a gated cardiac study, all of the following are true EXCEPT&#10;A) a significant amount of disk space is required to store the data.&#10;B) physiological markers are placed in the list of data.&#10;C) calculations can be made from selected data.&#10;D) timing marks are not needed for data collection.

Accepted Answer

In list mode acquisition, a timing mark is stored along with the x and y locations of the scintillations event. In addition, a physiological marker is placed in the list of data. List mode acquisition mode requires a significant amount of storage but the advantage is that acquired data can be evaluated and images constructed only from those desired heart rates. The advantage of this technique is that after data have been acquired as a list of gamma-ray events, the data can be evaluated, the desired R-R interval can be selected from the acquired data, and images can be constructed only from those of the desired heart rate. If the reformatted data are found to be unacceptable, a new R-R interval can be selected and a new series of images can be formatted.

Question 9

The image density for each pixel is determined by&#10;A) the gamma-ray counts stored within a pixel.&#10;B) the ratio of the z pulse to the x and y pulse.&#10;C) the counts detected minus the rollover counts.&#10;D) size of the matrices in which the pixels configured.

Accepted Answer

The image density for each pixel is determined by the number of gamma-ray counts stored within a pixel. For image display, the highest pixel count is assigned the brightest intensity on the display with other pixel counts assigned to appropriate intermediate and lower intensities.

Question 10

When using nine-point image smoothing, all of the following is true EXCEPT&#10;A) there is a slight increase in image resolution.&#10;B) there is a slight decrease in image resolution.&#10;C) there is a blending of pixel values.&#10;D) it creates a more aesthetic image.

Accepted Answer

Nine-point smoothing blends each pixel value with those of its neighbors, creating a smoother, more aesthetic image; however, there is a slight loss of resolution and the detail is slightly blurred.

Question 11

If a pixel can contain only 1 byte of information, and if the counts per pixel reaches 256 counts, pixel rollover may occur and would result in the&#10;A) averaging of all of the subsequent counts before storage.&#10;B) addition of the subsequent counts to the pixel counts.&#10;C) pixel value going back to 0.&#10;D) spillage of counts into the adjoining pixel.

Accepted Answer

The answer of If a pixel can contain only 1...

Question 12

A 256 * 256 matrix has a smaller pixel size than does a 64 * 64 matrix.

Accepted Answer

The answer of A 256 * 256 matrix has a...

Question 13

In an imaging computer system, the analog-to-digital converter (ADC) allows for the&#10;A) localization of the appropriate pixel into which the gamma event is recorded.&#10;B) averaging of the x, y, and z pulses.&#10;C) processing of the energy pulse by the pulse-height analyzer.&#10;D) conversion of x and y information into analog format.

Accepted Answer

The answer of In an imaging computer system, the analog-to-digital...

Question 14

Digital Imaging and Communications in Medicine (DICOM) is the standard for&#10;A) analog to digital conversion.&#10;B) filtering software.&#10;C) the system in each hospital for archiving EHRs.&#10;D) data set-up to allow for image transfer among systems.

Accepted Answer

The answer of Digital Imaging and Communications in Medicine (DICOM)...

Question 15

Dynamic data acquisition during a multiple gated acquisition is linked to the&#10;A) P wave.&#10;B) R wave.&#10;C) SA node.&#10;D) Q wave.

Accepted Answer

The answer of Dynamic data acquisition during a multiple gated...

Deck 9: Health Informatics in Imaging