CCD/CMOS EXAM REVIEW QIESTIONS
AND ANSWERS COMPLETE AND
VERIFIED.
What are the things that contribute to noise in CCD technology?
Anything that interferes with signal. Patient size, signal to noise (proper mAs)
What are the 3 types of noise in CCD technology?
1. Statistical noise (we can control),
2. dark current noise (problem is that CCD always stays on)
3. amplification noise (if something is dying, other pixels are working too hard
to overcome the difference)
Explain the difference in the path of electron travel out of the pixel array in
CMOS vs, Flat Panel detectors
FPD: through data lines & out
What does CMOS stand for?
Complementary metal oxide semiconductor
When was CMOS technology developed?
Early 1960
CMOS technology is similar to what other digital radiography technology?
FPD
What makes it unique?
Less dose with good resolution (less technical power with good detail)
, Of the 6 digital technologies, which one has the largest smallest largest
DEL?
Largest: CCD (nothing is obscuring it) Smallest: CMOS (it has 2 switches)
Of the 6 digital technologies, which one has the smallest pixel pitch?
CCD (they are bundled up on top of each other/next to each other)
Film screen:
best for detail (most lines per millimeter)
PSP: multiple
readers/ multiple rooms
Indirect unstructured FPD:
rugged
Indirect structured
FPD: better signal (xray into light)
Direct FPD:
more signal, less noise, no light step
CCD:
biggest DEL, fast/compact
CMOS:
uses 100x less power, shows biggest promise (detail & dose is better)
Using the above illustration, explain how positioning of the x-ray and
image intensifier should be in relationship to the patient. B. What is the
best way to get more signal and less noise? C. Where would the CCD be
placed in the above illustration?
A. XRAY TUBE SHOULD BE 15 INCHES FROM PATIENT (IF ITS CLOSER SKIN
ERYTHEMA) (I.I AS CLOSE TO PATIENT AS POSSIBLE BECAUSE IT REDUCES
PATIENT DOSE & THERES MORE PHOTONS TO IMAGE RECEPTOR & BETTER
AND ANSWERS COMPLETE AND
VERIFIED.
What are the things that contribute to noise in CCD technology?
Anything that interferes with signal. Patient size, signal to noise (proper mAs)
What are the 3 types of noise in CCD technology?
1. Statistical noise (we can control),
2. dark current noise (problem is that CCD always stays on)
3. amplification noise (if something is dying, other pixels are working too hard
to overcome the difference)
Explain the difference in the path of electron travel out of the pixel array in
CMOS vs, Flat Panel detectors
FPD: through data lines & out
What does CMOS stand for?
Complementary metal oxide semiconductor
When was CMOS technology developed?
Early 1960
CMOS technology is similar to what other digital radiography technology?
FPD
What makes it unique?
Less dose with good resolution (less technical power with good detail)
, Of the 6 digital technologies, which one has the largest smallest largest
DEL?
Largest: CCD (nothing is obscuring it) Smallest: CMOS (it has 2 switches)
Of the 6 digital technologies, which one has the smallest pixel pitch?
CCD (they are bundled up on top of each other/next to each other)
Film screen:
best for detail (most lines per millimeter)
PSP: multiple
readers/ multiple rooms
Indirect unstructured FPD:
rugged
Indirect structured
FPD: better signal (xray into light)
Direct FPD:
more signal, less noise, no light step
CCD:
biggest DEL, fast/compact
CMOS:
uses 100x less power, shows biggest promise (detail & dose is better)
Using the above illustration, explain how positioning of the x-ray and
image intensifier should be in relationship to the patient. B. What is the
best way to get more signal and less noise? C. Where would the CCD be
placed in the above illustration?
A. XRAY TUBE SHOULD BE 15 INCHES FROM PATIENT (IF ITS CLOSER SKIN
ERYTHEMA) (I.I AS CLOSE TO PATIENT AS POSSIBLE BECAUSE IT REDUCES
PATIENT DOSE & THERES MORE PHOTONS TO IMAGE RECEPTOR & BETTER
