LRA 221 Final: Digital Imaging, CR/DR
Basics, Image Quality & PACS UPDATED
Study Guide QUESTIONS AND
CORRECT ANSWERS
- CR image acquisition - CORRECT ANSWERS PSP plate
stores latent image → laser scans plate → emitted light converted to
digital signal.
Two elements needed to convert light to electrical signal in Indirect
DR - CORRECT ANSWERS Scintillator + photodiode (a-Si).
X-ray absorber used in Direct DR - CORRECT ANSWERS
Amorphous selenium (a-Se).
Device that releases latent image from PSP - CORRECT ANSWERS
Laser beam.
Photoconductor - CORRECT ANSWERS Material that
converts X-rays directly into electrical charge (ex: a-Se).
Look-Up Table (LUT) - CORRECT ANSWERS Reference
data that controls correct brightness & contrast.
Preset image annotation - CORRECT ANSWERS On-screen
labels (L/R, supine, portable).
, Indirect Capture DR - CORRECT ANSWERS X-rays → light
→ electrical signal → digital image.
DICOM - CORRECT ANSWERS Standard for medical images
and communication.
Pixel - CORRECT ANSWERS A square in a matrix.
Bit depth - CORRECT ANSWERS Number of gray levels a
pixel can display.
Deviation Index (DI) - CORRECT ANSWERS Shows how far
exposure is from the ideal target.
KIND - CORRECT ANSWERS Actual exposure to detector.
KTGT - CORRECT ANSWERS Target exposure for that
exam.
Brightness - CORRECT ANSWERS Displayed pixel value on
monitor.
Contrast resolution - CORRECT ANSWERS Ability to
differentiate small differences in tissue.
Basics, Image Quality & PACS UPDATED
Study Guide QUESTIONS AND
CORRECT ANSWERS
- CR image acquisition - CORRECT ANSWERS PSP plate
stores latent image → laser scans plate → emitted light converted to
digital signal.
Two elements needed to convert light to electrical signal in Indirect
DR - CORRECT ANSWERS Scintillator + photodiode (a-Si).
X-ray absorber used in Direct DR - CORRECT ANSWERS
Amorphous selenium (a-Se).
Device that releases latent image from PSP - CORRECT ANSWERS
Laser beam.
Photoconductor - CORRECT ANSWERS Material that
converts X-rays directly into electrical charge (ex: a-Se).
Look-Up Table (LUT) - CORRECT ANSWERS Reference
data that controls correct brightness & contrast.
Preset image annotation - CORRECT ANSWERS On-screen
labels (L/R, supine, portable).
, Indirect Capture DR - CORRECT ANSWERS X-rays → light
→ electrical signal → digital image.
DICOM - CORRECT ANSWERS Standard for medical images
and communication.
Pixel - CORRECT ANSWERS A square in a matrix.
Bit depth - CORRECT ANSWERS Number of gray levels a
pixel can display.
Deviation Index (DI) - CORRECT ANSWERS Shows how far
exposure is from the ideal target.
KIND - CORRECT ANSWERS Actual exposure to detector.
KTGT - CORRECT ANSWERS Target exposure for that
exam.
Brightness - CORRECT ANSWERS Displayed pixel value on
monitor.
Contrast resolution - CORRECT ANSWERS Ability to
differentiate small differences in tissue.
