Equipment
What is the primary function of the diagnostic type protective tube housing in radiographic equipment?
To protect patients and personnel from off-focus (leakage) radiation
The gradual increase in exposure techniques over time because digital systems can correct for overexposure is known as:
Dose Creep
When using a C-arm, placing the x-ray tube under the table and the image intensifier above the patient is recommended because it:
The use of proper radiologic techniques during fluoroscopy calls to _____ _______ between the x-ray tube and patient.
Maximize distance
T or F
DR produces instant images, and lowers repeat rates when used correctly
True
What is the primary purpose of a light-localizing variable-aperture rectangular collimator?
The restrict the primary x-ray beam to the size of the anatomical area of interest
In fluoroscopy, which feature allows the operator to view the most recently captured image without continuous x-ray exposure?
Last Image Hold
The cumulative timer in a fluoroscopic unit is designed to produce an audible alarm or pause the beam after how much time has elapsed?
Every 5 mins
In 1974 the FDA alerted health care works to:
The risk of patient overexposure from high-level fluoroscopy and the need for caution
The largest patient radiation exposure rates in diagnostic radiology are:
Fluoroscopic procedures
What is the function of the mandatory backup timer in an Automatic Exposure Control (AEC) system?
To protect the patient from excessive overexposure in case of AEC malfunction
How does increasing grid ratio affect patient radiation dose?
Patient dose increases because more mAs is required
What is the primary purpose of High-Level Control (HCL) fluoroscopy in interventional procedures?
To allow visualization of small, low- contrast objects like stents and catheters
A long term strategy to manage radiation dose during fluoroscopy to the operator and staff include:
Training operators and staff in good positioning for the use of fluoroscopy equipment.
Name two parts on the image intensifier
Acceptable answers: focal point, output phosphor, anode, electrostatic lenses, electrons, photocathode, input phosphor, glass envelope
For fixed radiographic equipment, what is the minimum required distance between the patient’s skin and the collimator to ensure skin sparing?
15 cm
What does the term ‘Half-Value Layer’ (HVL) measure in radiography?
The thickness of absorber needed to decrease beam intensity by 50%
What is the minimum required Source-to-Skin Distance (SSD) for mobile fluoroscopic systems (C-arms)?
30 cm (12 in)
Name 2 procedures that extend fluoroscopic time:
- percutaneous transluminal angioplasty
-radiofrequency cardiac catheter ablation
- vascular embolization
-Stent and filter placement
- thrombolytic and fibrinolytic procedures
- percutaneous transhepatic cholangiography
- endoscopic retrograde cholangiography
- transjugular intrahepatic portosystemic shunt
What is the difference between inherent filtration vs added filtration:
Inherent filtration is built in, think like the glass envelope or the tube housing window and added filtration is placed outside the tube for example thin sheets of aluminum