Download Lecture 1(3) - Sources in diagnostic Rad - gnssn

Radiation Sources in medicine
diagnostic Radiology
Interventional Radiology
IAEA
International Atomic Energy Agency
Day 7 – Lecture 1(3)
Objective
• To become familiar with the technology and operation of
interventional radiology x-ray systems.
• To become familiar with the specific radiation risks for
patients and staff associated with interventional radiology.
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Contents
• Description of interventional radiology x-ray systems.
• Equipment malfunction affecting radiation protection.
• Criteria of acceptability and quality control.
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Interventional Radiology
Interventional radiology uses
x-ray imaging to guide the
placement of catheters, stents
etc. in blood vessels and
organs for the purpose of
correcting or treating a
particular condition.
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Interventional Radiology (cont)
When contrast media is used to
outline blood vessels, the technique
of digital subtraction angiography
(DSA) may also be used.
During DSA, a “negative” digital
fluoroscopic image of the body part
under examination is digitally combined
Queensland Diagnostic Imaging
with each frame of the subsequent
The resultant image (in
fluoroscopic image while a contrast
real time or recorded) is
medium is injected into the blood
displayed largely free of
vessels.
anatomy that might
otherwise obscure the
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blood vessels.
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Interventional Radiology (cont)
A fluoroscopic
system that
can be used
for DSA and
interventional
radiology.
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Interventional Radiology (cont)
•
Comprises fluoroscopically guided invasive procedures that
predominantly have a therapeutic objective. Access to the
organ or vessel of interest is usually percutaneous and
generally performed under local anesthesia and / or sedation.
•
Fluoroscopy is commonly used but computed tomography
and ultrasound may also be used.
•
Compared to other fluoroscopic procedures, fluoroscopic
exposure times can be long and may be combined with
extensive radiographic exposures.
•
Patient and staff radiation doses can be high.
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Interventional Radiology (cont)
• Fluoroscopic systems used for interventional radiology must
comply with the basic requirements that are applicable to
fluoroscopic equipment (Module 2.4).
• Because the accumulated patient dose may be high, the
equipment shall incorporate a continuous indication of
patient dose such as a Dose-Area Product meter.
• A device must indicate the total elapsed fluoroscopic
exposure time for each patient and provide an audible
warning to the fluoroscopist at a predetermined interval,
preferably not exceeding 5 minutes.
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Malfunctions affecting radiation protection
The types of malfunctions that should be considered are:
• generator, x-ray tube and imaging system deficiencies
listed in Modules 2.1 and 2.2, and
• fluoroscopy system problems listed in Module 2.4.
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Problems affecting radiation protection
Assuming appropriate dedicated equipment is used, it
functions correctly, is properly maintained and is subject to a
quality assurance programme, other causes of avoidable
patient and staff exposure during interventional radiology
might result from:
• complex procedures which are not optimized (exposure
parameters, the number of images acquired, dose rate,
patient positioning, etc.);
• inadequate radiation protection training received by
interventional physicians.
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