COMPUTED TOMOGRAPHY- EXAM QUESTIONS AND CORRECT ANSWERS (GRADED A+)
THE ABILITY TO SCAN MOVING OBJECTS EFFECTIVELY IS - Answers TEMPORAL RESOLUTION
WHEN A CT IMAGE APPEARS GRAINY OR SPECKLED IT IS REFERRED TO AS A - Answers NOISY IMAGE
HOW IS NOISE REDUCED - Answers BY INCREASING
1. mAs 2. slice thickness 3. pixel size
IF MORE PHOTONS ARE DETECTED THE NOISE IS - Answers LESS APPARENT
WHAT IS CREATED WHEN THE HOUNSFIELD NUMBERS ARE NOT ACCURATE FOR CONSISTENT MATERIAL
BECAUSE OF BEAM DIVERGENCE - Answers CUPPING ARTIFACT
WATER HAS A HOUNSFIELD UNIT OF - Answers ZERO
BONE HAS A HOUNSFIELD UNIT OF - Answers 1000
POINT OF SPREAD FUNCTION - Answers THE LACK OF SHARPNESS THAT OCCURS WHEN A POINT IN THE
OBJECT BEING SCANNED IS NOT A REPRESENTED AS A TRUE POINT ON THE IMAGE
LINE SPREAD FUNCTION - Answers DESCRIBES THE UNSHARPNESS OF AN IMAGING SYSTEM IN TERMS
OF BREAKING DOWN AN OBJECT INTO FREQUENCY COMPONENTS
HOW CAN SPATIAL RESOLUTION BE IMPROVED? - Answers USING THIN SLICE THICKNESS
AN IMAGE MATRIX WITH A SMALL PIXEL SIZE
RECONSTRUCTION FILTERS SUXH AS HIGH-FREQUENCY CONVOLUTION FILTER
AND A SMALL DETECTOR SIZE
WHAT IS TEMPORAL RESOLUTION USUALLY ASSOCIATED WITH - Answers CARDIAC IMAGING
WHAT FACTORS CAN YOU AS THE TECH CONTROL THAT AFFECT IMAGE QUALITY? - Answers SELECTABLE
SCAN PARAMETERS AND VIEWING CONDITIONS
WHAT FACTORS CANNOT BE CONTROL BY YOU? - Answers PT SIZE, BEAM GEOMETRY, AND IMAGE
RECEPTOR TYPE
IN THIRD GENERATION CT SCANNERS THE FOCAL SPOT SIZE IS RELATED TO - Answers SPATIAL
RESOLUTION
THE SMALLER THE FOCAL SPOT SIZE THE BETTER - Answers SPATIAL RESOLUTION
WHAT IS A DISADVANTAGE OF USING A SMALL FOCAL SPOT SIZE? - Answers IT CAN INCREASE TUBE
HEATING ON THE ANODE
, WHAT DOES BEAM GEOMETRY REFER TO? - Answers THE PATH OF THE XRAY BEAM TAKES ONCE IT
LEAVES THE XRAY TUBE, PASSES THROUGH THE PT AND STRIKES THE DETECTORS
WHAT TYPE OF BEAM GEOMETRY DO FIRST GENERATIONS SCANNERS HAVE? - Answers PARALLEL,
PENCIL BEAM
WHAT TYPE OF BEAM GEOMETRY DO SECOND GENERATION SCANNERS HAVE? - Answers FAN BEAM
WHAT TYPE OF BEAM GEOMETRY DO THIRD GENERATION SCANNERS HAVE? - Answers EVEN WIDER
FAN BEAM
A WIDER BEAM PRODUCES MORE - Answers SCATTERED RADIATION
WHAT TYPE OF BEAM GEOMETRY DO MODERN CT SCANNERS HAVE? - Answers CONE-BEAM
IN THIRD GENERATION SCANNERS FOCAL SPOT SIZE IS RELATED TO - Answers SPATIAL RESOLUTION
WHAT KIND OF DETECTORS ARE USED IN CT? - Answers GAS AND SCINTILLATION
WHY DO MODERN CT SCANNERS USE SCINTILLATION DETECTORS MORE OFTEN? - Answers THEY NEED
LESS RECALIBRATION AND ARE MORE EFFICIENT AND LESS NOISY
VERY LG PT MAY PRODUCE _______-____-_______ ___________ BECAUSE THEIR ENTIRE ANATOMY
CANNOT FIT WITHIN THE SCAN FILED OF VIEW - Answers OUT-OF-FIELD ARTIFACTS
WHAT IS THE APPROXIMATE MAS LEVEL IN CT - Answers 200
HAVING A HIGH MA SETTING REDUCES - Answers IMAGE NOISE
INCREASING THE MAS WILL REDUCE IMAGE NOISE BUT IT WILL INCREASE ___________ ___________ -
Answers PT DOSE
THE DISPLAY FIELD OF VIEW IS ALSO KNOWN AS - Answers RECONSTRUCTION FIELD OF VIEW
THE DISPLAY FIELD OF VIEW IS ALWAYS __________________ THEN THE SCAN FIELD OF VIEW - Answers
SMALLER
T/F
THE FIELD OF VIEW CAN AFFECT IMAGE NOISE AND RESOLUTION - Answers TRUE
WHAT IS ANOTHER TERM FOR FORWARD IN CT - Answers INDEX
THIS TYPE OF FILTER REMOVES BLURRING AND ARTIFACTS - Answers CONVOLUTION OR KERNEL
WHAT ARE THEY TYPICAL KVP SETTINGS IN CT - Answers 100
120
THE ABILITY TO SCAN MOVING OBJECTS EFFECTIVELY IS - Answers TEMPORAL RESOLUTION
WHEN A CT IMAGE APPEARS GRAINY OR SPECKLED IT IS REFERRED TO AS A - Answers NOISY IMAGE
HOW IS NOISE REDUCED - Answers BY INCREASING
1. mAs 2. slice thickness 3. pixel size
IF MORE PHOTONS ARE DETECTED THE NOISE IS - Answers LESS APPARENT
WHAT IS CREATED WHEN THE HOUNSFIELD NUMBERS ARE NOT ACCURATE FOR CONSISTENT MATERIAL
BECAUSE OF BEAM DIVERGENCE - Answers CUPPING ARTIFACT
WATER HAS A HOUNSFIELD UNIT OF - Answers ZERO
BONE HAS A HOUNSFIELD UNIT OF - Answers 1000
POINT OF SPREAD FUNCTION - Answers THE LACK OF SHARPNESS THAT OCCURS WHEN A POINT IN THE
OBJECT BEING SCANNED IS NOT A REPRESENTED AS A TRUE POINT ON THE IMAGE
LINE SPREAD FUNCTION - Answers DESCRIBES THE UNSHARPNESS OF AN IMAGING SYSTEM IN TERMS
OF BREAKING DOWN AN OBJECT INTO FREQUENCY COMPONENTS
HOW CAN SPATIAL RESOLUTION BE IMPROVED? - Answers USING THIN SLICE THICKNESS
AN IMAGE MATRIX WITH A SMALL PIXEL SIZE
RECONSTRUCTION FILTERS SUXH AS HIGH-FREQUENCY CONVOLUTION FILTER
AND A SMALL DETECTOR SIZE
WHAT IS TEMPORAL RESOLUTION USUALLY ASSOCIATED WITH - Answers CARDIAC IMAGING
WHAT FACTORS CAN YOU AS THE TECH CONTROL THAT AFFECT IMAGE QUALITY? - Answers SELECTABLE
SCAN PARAMETERS AND VIEWING CONDITIONS
WHAT FACTORS CANNOT BE CONTROL BY YOU? - Answers PT SIZE, BEAM GEOMETRY, AND IMAGE
RECEPTOR TYPE
IN THIRD GENERATION CT SCANNERS THE FOCAL SPOT SIZE IS RELATED TO - Answers SPATIAL
RESOLUTION
THE SMALLER THE FOCAL SPOT SIZE THE BETTER - Answers SPATIAL RESOLUTION
WHAT IS A DISADVANTAGE OF USING A SMALL FOCAL SPOT SIZE? - Answers IT CAN INCREASE TUBE
HEATING ON THE ANODE
, WHAT DOES BEAM GEOMETRY REFER TO? - Answers THE PATH OF THE XRAY BEAM TAKES ONCE IT
LEAVES THE XRAY TUBE, PASSES THROUGH THE PT AND STRIKES THE DETECTORS
WHAT TYPE OF BEAM GEOMETRY DO FIRST GENERATIONS SCANNERS HAVE? - Answers PARALLEL,
PENCIL BEAM
WHAT TYPE OF BEAM GEOMETRY DO SECOND GENERATION SCANNERS HAVE? - Answers FAN BEAM
WHAT TYPE OF BEAM GEOMETRY DO THIRD GENERATION SCANNERS HAVE? - Answers EVEN WIDER
FAN BEAM
A WIDER BEAM PRODUCES MORE - Answers SCATTERED RADIATION
WHAT TYPE OF BEAM GEOMETRY DO MODERN CT SCANNERS HAVE? - Answers CONE-BEAM
IN THIRD GENERATION SCANNERS FOCAL SPOT SIZE IS RELATED TO - Answers SPATIAL RESOLUTION
WHAT KIND OF DETECTORS ARE USED IN CT? - Answers GAS AND SCINTILLATION
WHY DO MODERN CT SCANNERS USE SCINTILLATION DETECTORS MORE OFTEN? - Answers THEY NEED
LESS RECALIBRATION AND ARE MORE EFFICIENT AND LESS NOISY
VERY LG PT MAY PRODUCE _______-____-_______ ___________ BECAUSE THEIR ENTIRE ANATOMY
CANNOT FIT WITHIN THE SCAN FILED OF VIEW - Answers OUT-OF-FIELD ARTIFACTS
WHAT IS THE APPROXIMATE MAS LEVEL IN CT - Answers 200
HAVING A HIGH MA SETTING REDUCES - Answers IMAGE NOISE
INCREASING THE MAS WILL REDUCE IMAGE NOISE BUT IT WILL INCREASE ___________ ___________ -
Answers PT DOSE
THE DISPLAY FIELD OF VIEW IS ALSO KNOWN AS - Answers RECONSTRUCTION FIELD OF VIEW
THE DISPLAY FIELD OF VIEW IS ALWAYS __________________ THEN THE SCAN FIELD OF VIEW - Answers
SMALLER
T/F
THE FIELD OF VIEW CAN AFFECT IMAGE NOISE AND RESOLUTION - Answers TRUE
WHAT IS ANOTHER TERM FOR FORWARD IN CT - Answers INDEX
THIS TYPE OF FILTER REMOVES BLURRING AND ARTIFACTS - Answers CONVOLUTION OR KERNEL
WHAT ARE THEY TYPICAL KVP SETTINGS IN CT - Answers 100
120
