Section 3 Flashcards
What is a pixel?
smallest amount of info in 2D image
What is matrix size?
Number of pixels
Few # of pixels =
coarse
Big # of pixels =
fine
Image size/FOV is
size of anatomical area being imaged
Matrix size =
image size/ pixel size
A binary digit can be
0 or 1
Bit depth is
number of bits per pixel
Higher bit depth means
more contrast
1 byte has how many bits?
8 bits
Resolution is the
image property of the ability for the smallest objects (detail) to be seen as separate
Higher resolution means that you can
resolve the details that are smaller
Low resolution is
blurring as a larger separation is needed
A histogram is
a plot of # occuances ofpixel values
Histogram equalisation adjusts the
contrast to expand histogram and keep shades that contribute diagnostic info
Filtering is used
to enhance the certain aspects of the image
How are coregistration and image subtraction different?
Coreg is about aligning the 2 images spatially whereas image subraction is about comparing the differences between 2 images
What does compression ratio describe
describes the level of compression
Which type of compression has a higher ratio
lossy compression
DICOM stands for
Digital Imaging & Communications in Medicine
PACS stand for
Picture Archiving & Communication System
Lossless is where
the information is not lost
What do we change in co-registration?
We can alter the kVp, the radiopharmaceutical, different imaging modalities
DSA stands for
digital subraction angiography
