RTBC- quality control Questions and Answers Latest Updated

RTBC- quality control Questions and Answers Latest Updated The central ray indicator must align to the actual center of the x-ray field with a tolerance of: 1% source-to-image distance (SID) The Source-to-Image Distance (SID) indicator misrepresent, the actual SID within a tolerance of: +- 2% of the SID The light field must correspond to the actual exposure field within a tolerance of: +- 2% of the SID " coincidence testing" of the x-ray to assembly is an evaluation of which of the following? Light field accuracy When the source to image distance (SID) is 80cm (31 inches), the actual century should be within what distance of the indicated x-ray field center? 0.8 cm (0.3 inches) At a source to image distance (SID) of 60 inches (152 cm), the central ray must align to the central ray indicator within: 0.6 inch (1.5cm) What is the primary purpose of regularly testing in calibrating the central ray alignment? Maintain the accuracy of the radiographic projection When the source the image distance (SID) is 80cm (31.5 inches), the actual SID should match the displayed SID within a range of: +-1.6 cm (0.6 inches) When the source the image distance (SID) is 80 cm (31.5 inches), the Light field should match the exposure field within a range of: +-1.6 cm (0.6 inches) When the source the image distance (SID) is 40 inches (102 cm), the actual SID should match the displayed SID within a range of: +- 0.8 inches (4.1 cm) Actual exposure time must be within what percentage of indicated exposure time? +-5% The actual exposure time must be accurate within what range when the assigned exposure time is 80 milliseconds (ms)? +-4.0 ms The actual exposure time must be accurate within what range when the assigned exposure time is 100 milliseconds (ms) +-5 ms The actual exposure time must be accurate within what range when the assigned exposure time is 72 milliseconds (ms) +-3.6 ms If the assigned exposure time is 60 milliseconds (ms), the actual exposure time should be no more than: 63.0 ms Which of these exposure times is outside acceptable limits when the exposure time on the operators consul, is set to 300 milliseconds (ms) 316 ms Consider this scenario: a medical physicist is testing an automatic exposure control (AEC) system. If an exposure through 1 cm of aluminum results in a receptor exposure of 10 micro gray, and exposure through 2 centimeters of aluminum should result in a receptor exposure of: 10 microgray (ugy) Consider this scenario: a medical physicist is testing an automatic exposure control (AEC) system. If an exposure through 10 cm of aluminum results in a receptor exposure of 100 micro gray, and exposure through 5 centimeters of aluminum should result in a receptor exposure of: 100 microgray (ugy) A radiograph is acquired using an automatic exposure controlled (AEC) unit with an exposure setting of 200 milliamperage (mA) and 60 Kilovoltage peak (kVp). If the initial receptor exposure is measured as 20 micro gray (Ugy), increasing the technique to 69 kVp will result in a receptor exposure of: 20 uGy A radiograph is acquired using an automatic exposure controlled (AEC) unit with an exposure setting of 200 milliamperage (mA) and 100 Kilovoltage peak (kVp). If the initial receptor exposure is measured as 50 micro gray (Ugy), increasing the technique to 300 kVp will result in a receptor exposure of: 50 Ugy the actual Kilovoltage peak (kVp) of an X-ray exposure must correspond to the selected kVp within a tolerance of what percentage? +-5% X-ray systems must demonstrate consistent exposure reproducibility within a tolerance of what percentage +-5% The X-ray tube output for identical technical parameters should not vary by more than what percentage? +-5% The milligray/milliampere-seconds (mGy/mAs) measurement between adjacent mA stations should not vary by more than: +-10% X-ray systems must demonstrate exposure linearity between adjacent milliamperage (mA) stations within a tolerance of what percentage? +-10% When selected tube is 80 Kilovoltage peak (kVp), the actual kVp must be accurate within a range of: +-4.0 kVp During annual control testing, the beam intensity measures 300 microgray (UGY) for an exposure performed at 100 Kilovoltage peak (kVp) and 10 milliampere-seconds (mAs). A second exposure performed with the same technique should match the first exposure within a tolerance of: +-15.0 uGy A diagnostic X-ray system must demonstrate exposure linearity within an error margin of what percentage? +-10% An exposure performed at 70 Kilovoltage peak (kVp) and 10 milliampere-seconds (mAs) produces a beam intensity of 342 microgray (Ugy). Calculate the Ugy/mAs. 34.2 uGy/mAs An X-ray system with unreliable exposure reproducibility may result in which two adverse effects? (Select two) -unnecessary patient dose -inadequate receptor exposure Three different detectors were expiases using a technique of 80 Kilovoltage peak (kVp) and 5 milliampere-seconds (mAs). The deviation index (DI) for each detector was recorded as: DI for detector 1= +2 DI for detector 2= +2 DI for detector 3= +1 the irregular DI for detector 3 indicates a quality control issue related to which of the following? Detector calibration Exposure of a small lead block is a technique used to evaluate which of the following? Reader erasure thoroughness A blank image receptor is exposed and processed. The resulting image shows an area on the plate with a lower radiation response. This may be a problem with which of the following? Plate uniformity Which aspect of an image receptor system is evaluated using a line-pairs pattern? Spatial resolution