NMT 422 Quiz 2
For better resolution of smallest objects in the FOV, an ideal choice of pixel size would be: 1/3rd of the system spatial resolution 3 times the system resolution same as system resolution highest matrix size available
1/3rd of the system spatial resolution
How much memory is required to collect a MUGA study acquired in a 64 x 64 word mode matrix, 16 frames/cycle? 64KB 128KB 256KB 512KB
128 KB
In byte mode acquisition, each pixel can hold a maximum of how many counts? 255 256 65,535 65,536
255
A camera has a field of view of 51cm2. If a 128x128 matrix is used with a zoom factor of 1.6 what will be the new FOV?
32 cm^2
In word mode acquisition, each pixel can hold a maximum of how many counts? 255 256 65,535 65,536
65,535
The following separates frames required for each selected photopeak: Static Dynamic Gated Gated SPECT Dual Radionuclide
Dual Radionuclide
Images can be viewed DURING acquisition in all of the following: Static, dynamic and gated frame mode Gated and non-gated SPECT mode Dual radionuclide mode list mode
Dual Radionuclide method Gated and non-gated SPECT mode Static, dynamic, and frame mode
Which frame mode occurs when two or more sections of memory are set aside for image matrices and data is stored as a series f images? Static Dynamic Gated Gated SPECT Dual Radionuclide
Dynamic
An acquisition zoom factor of 2 means: of view is doubled field of view is halved no effects on the size of the field of view but image is magnified field of view is quadrupled
FOV is halved
A 64x64 matrix will have better spatial resolution than 256 x 256 matrix. True or False
False
DURING frame mode acquisition, data is written directly to the hard disk while acquisition is going on and hence cannot be lost. True or False
False
In choosing an appropriate size pixel, oversampling or using a pixel size smaller than needed degrades image quality: True or False
False
In zoom mode acquisition, increase in spatial resolution is achieved by increasing the number of pixels in FOV. True or False
False
Larger the matrix size, lesser the storage space required. True or False
False
Which of the following modes allows for immediate images, losses time of relationship between counts, may be limited, and data is only reformed by adding frames together. Frame Mode List Mode
Frame Mode
Which frame mode uses a physiological event to trigger the computer to start acquisition? Static Dynamic Gated Gated SPECT Dual Radionuclide
Gated
The following frame mode is a cardiac study which accesses MUGA in multiple angles of the heart and requires 8 times more memory. Static Dynamic Gated Gated SPECT Dual Radionuclide
Gated SPECT
For a given FOV, pixel size decreases as matrix size:
Increases
Which of the following is a list of counts in the order in which they occurred and is also terminated when: preset time reached, preset counts reached, no disk space left. Frame Mode List Mode
List Mode
Which of the following modes allows for the relationship between counts to remain, data may be reframed in multiple formats, is a lengthy process, and can be used with high framing rates. Frame Mode List Mode
List Mode
Hardware zoom results in all of the following: magnifies image counts from the central regions are now in the periphery counts from edges moves out of FOV can be done while processing the image
Magnifies Image Counts from the central regions are now in the periphery. counts from edges move out of FOV
Software zoom magnifies image by: decreasing pixel size Pixel replication increasing pixel size decreasing the field of view
Pixel replication
How well an image is sampled depends on adjusting what? area sampled FWHM pixel size injected counts
Pixel size
Doubling the matrix, _________ the number of pixels in FOV: halves doubles triples quadruples
Quadruples
Which frame mode is terminated when: preset counts are reached, preset collection time is reached, max counts/pixels reached, and the operator manually stops data collection? Static Dynamic Gated Gated SPECT Dual Radionuclide
Static
Give an example of a study for each of the following frame modes: Static Dynamic Gated Gated SPECT Dual Radionuclide
Static (Bone) Dynamic (HIDA) Gated (MUGA) Gated SPECT (Heart) Dual Radionuclide (Parathyroid)
Temporal (time) information of radioactivity concentration in the body can be obtained by all of the following acquisition modes, EXCEPT: Static frame mode Dynamic frame mode Gated frame/ SPECT mode List mode
Static Frame Mode
Hardware zoom improves spatial resolution of the objects imaged. True or False
True
In a gamma camera, the analog to digital converter (ADC) converts which of the analog position signals to digital format? x Y z x & y x, y, & z
X,Y, and Z
Hardware zoom is done: before acquisition using the acquisition terminal after acquisition using the processing terminal during acquisition by bringing the camera head closer to the patient
before acquisition using the acquisition terminal
In gated cardiac acquisition: all cardiac cycles are acquired into 1 frame each cardiac cycle is divided into multiple frames gated study is a static acquisition
each cardiac cycle is divided into multiple frames
Software zoom increases spatial resolution of objects. True or False
false
Matrix size refers to: Size of a pixel Size of the FOV Number of pixels Depth of a pixel
number of pixels
Which of the following is true about under sampling? clarity of image is unaffected results from large pixel sizes demands less memory space ideal for dynamic studies
results from large pixel demands less memory space ideal for dynamic studies
