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WorksheetsIMPCB - Math and Statistics I
Total questions: 20
Worksheet time: 20mins
What type of data is lost when you turn a computer off?
ROM
Hard Drive
RAM
Magnetic Tape
Random number generators randomly generate numbers
True
False
What is the most fundamental unit of information in a computer?
bit
int
bool
byte
A computer stores a 3D CT or MR image set as ____
A group of values corresponding to element intensity levels
An array of individual images with one image per Byte
A GPU (graphics processing unit)
A vector file
What is the component of a computer which reconstructs a CT image?
CCD
I/O board
CPU
RAM
How much storage is required for store an ASCII character?
1 bit
16 MB
1 MB
8 bits
512 x 512 images are stored on a 700MB disk. Each pixel is 16 bits. How many images can
the disk hold?
1,400 images
3,500 images
2,800 images
512 images
For a Poisson distribution with a mean of 10, what is the probability of obtaining exactly 10
counts?
38%
66.7%
12.5%
3.3%
What is the equation for the average function value?
Sample A is measured producing 20,000 counts. Sample B is measured under identical
conditions yielding 15,000 counts. Assuming standard uncertainty for each measurement, what
is the total uncertainty of the ratio of sample A to sample B?
0.005
0.17
0.014
0.75
When will radioisotopes A and B have the same activity?
15 hours
13 hours
21 hours
Never (a time prior to the initial time)
A radioactive sample is repeatedly counted yielding an average of 500 counts over one
minute. 95% of 1 minute counting studies will fall within what range?
433 to 567
495 to 505
455 to 545
478 to 522
Which statement is FALSE regarding a Poisson distribution?
Standard deviation as a percentage of the mean decreases as counts increase
Poisson distributions are used to describe only random binary events
Poisson distributions may be approximated by a binomial distribution for small sample
sizes
Radioactive decay may be accurately modeled by a Poisson distribution
Mean life if given by:
ln(T1/2)
0.7 x (T1/2)
1.44 x (T1/2)
3.1 x (T1/2)
A photon detector on an imaging system detects 202,500 photons in a measurement. What
is the probability that the same imaging system will measure between 202,950 and 203,400
counts on the next measurement?
13.5%
68%
34.1%
8.3%
Dose fall off from an infinite line source is proportional to:
r2
r
1/r2
1/r3
1/r
You drive from point A to point B at a rate of 100mph. When you return to point A from point
B you travel at 50mph. What is your average speed?
The solution is dependent on the distance between points A and B
67 mph
75 mph
59 mph
What is the ROC curve specificity of an imaging technique with the following performance
statistics.
True positive = 20
False positive = 5
True negative = 4
False negative = 7
0.17
0.44
0.83
0.67
Approximately how many half lives are required to reduce activity by 99%?
50 half lives
7 half lives
6.6 half lives
5 half lives
Select all equations which calculate which yield 1% of the original activity
4.6 / lambda
T(1/2) x 6.6
T(1/2, eff) / 34.4
T(mean) x 4.6
