Digital Image Processing-CT Exam
Questions and Answers 100% Solved
Limitations of film based imaging - ✔✔Been around since 1895 Used in all
radiology modalities. Patient is exposed to predetermined amount of
radiation that is needed to provide a diagnostic image. If image is
under/over penetrated the patient would have to be exposed again,
increasing dose. Not ideal way to perform radiation detection, image
display and image archiving. Film-screen(x-Ray) can't show differences in
tissue contrast less than 10%(contrast resolution). Optical range and
contrast for film are fixed and limited(can't window/level them, have to
retake). Stored in envelopes requires manual handling for archiving and
retrieval.
Major components of generic digital imaging system - ✔✔Data acquisition,
Image processing, Display/storage/archivingImage communication
Data acquisition - ✔✔1st step- systematic method of collecting data from
the patient, Attenuation data collected for imaging modality, Ct- x-Ray tube
and digital image detectors do this, Output signal is an electrical
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, signal(analog signal that varies continuously on time), Analog, signal must
be converted into a digital signal for, computer processing using an ADC
converter
Image processing - ✔✔Performed by digital computer , Takes input digital
image, processes it to produce output digital image(using binary number
system), ADC sends digital data for digital image processing by a digital
computer, Accomplished by set of operations, techniques to the input
image into an output image, these operations can reduce noise, enhance
sharpness, or change the contrast
Image display, storage, and communication - ✔✔Output digital image must
be converted into an analog signal before it can be displayed on the
monitor using a DAC, Can be archived on magnetic data carriers and laser
optical disks for retrospective viewing and manipulation, Can be
communicated electronically through computer networks to remote sites
Image formations and representation analog images - ✔✔Analog images
are continuous images, Images formed when x-rays pass through patient
and projected onto x-Ray film, Films processed in chemical solutions to
render visible. These images formed by photochemical process, Images
can be formed by photo electronic means, images may be represented as
electrical(analog) signals that emerge from photo electrical device
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
Questions and Answers 100% Solved
Limitations of film based imaging - ✔✔Been around since 1895 Used in all
radiology modalities. Patient is exposed to predetermined amount of
radiation that is needed to provide a diagnostic image. If image is
under/over penetrated the patient would have to be exposed again,
increasing dose. Not ideal way to perform radiation detection, image
display and image archiving. Film-screen(x-Ray) can't show differences in
tissue contrast less than 10%(contrast resolution). Optical range and
contrast for film are fixed and limited(can't window/level them, have to
retake). Stored in envelopes requires manual handling for archiving and
retrieval.
Major components of generic digital imaging system - ✔✔Data acquisition,
Image processing, Display/storage/archivingImage communication
Data acquisition - ✔✔1st step- systematic method of collecting data from
the patient, Attenuation data collected for imaging modality, Ct- x-Ray tube
and digital image detectors do this, Output signal is an electrical
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, signal(analog signal that varies continuously on time), Analog, signal must
be converted into a digital signal for, computer processing using an ADC
converter
Image processing - ✔✔Performed by digital computer , Takes input digital
image, processes it to produce output digital image(using binary number
system), ADC sends digital data for digital image processing by a digital
computer, Accomplished by set of operations, techniques to the input
image into an output image, these operations can reduce noise, enhance
sharpness, or change the contrast
Image display, storage, and communication - ✔✔Output digital image must
be converted into an analog signal before it can be displayed on the
monitor using a DAC, Can be archived on magnetic data carriers and laser
optical disks for retrospective viewing and manipulation, Can be
communicated electronically through computer networks to remote sites
Image formations and representation analog images - ✔✔Analog images
are continuous images, Images formed when x-rays pass through patient
and projected onto x-Ray film, Films processed in chemical solutions to
render visible. These images formed by photochemical process, Images
can be formed by photo electronic means, images may be represented as
electrical(analog) signals that emerge from photo electrical device
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
