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Questions and Answers
The radiologist had to adapt his eyes to the dark by staying in a dark room for at least ______ minutes before procedures.
The radiologist had to adapt his eyes to the dark by staying in a dark room for at least ______ minutes before procedures.
10
The invention of X-ray image ______ in the 1950s allowed images to be visible under normal lighting conditions.
The invention of X-ray image ______ in the 1950s allowed images to be visible under normal lighting conditions.
intensifiers
In 8 November 1895, Wilhelm Roentgen noticed a barium platinocyanide screen fluorescing that can be used for ______ images.
In 8 November 1895, Wilhelm Roentgen noticed a barium platinocyanide screen fluorescing that can be used for ______ images.
fluoroscopic
Fluoroscopy is used to evaluate the condition of coronary arteries during cardiac ______.
Fluoroscopy is used to evaluate the condition of coronary arteries during cardiac ______.
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The first fluoroscopes consisted of an x-ray tube and a ______ screen.
The first fluoroscopes consisted of an x-ray tube and a ______ screen.
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One purpose of fluoroscopy is to evaluate the structure and function of the urinary ______.
One purpose of fluoroscopy is to evaluate the structure and function of the urinary ______.
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In 1896, Thomas Edison discovered that cadmium ______ screens produced brighter images.
In 1896, Thomas Edison discovered that cadmium ______ screens produced brighter images.
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During orthopedic surgery, fluoroscopy is used to realign a fractured ______.
During orthopedic surgery, fluoroscopy is used to realign a fractured ______.
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Examination with early fluoroscopes would have occurred in a ______ room.
Examination with early fluoroscopes would have occurred in a ______ room.
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Early fluoroscopes were cardboard funnels that had an open end for the observers’ eyes while the wide end was closed with a thin cardboard piece covered with fluorescent ______.
Early fluoroscopes were cardboard funnels that had an open end for the observers’ eyes while the wide end was closed with a thin cardboard piece covered with fluorescent ______.
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Study Notes
Fluoroscopy Imaging System
- Fluoroscopy is a real-time imaging technique used to visualize the motion of internal structures or fluids.
- It produces dynamic views of x-ray images.
- Fluorescence is a material that emits visible light immediately in response to stimuli such as electric current or x-rays.
Learning Objectives
- Students should be able to explain the principles of fluoroscopic imaging systems.
- Students should be able to differentiate fluoroscopic and radiographic imaging.
- Students should be able to describe the components of a fluoroscopy imaging system.
Contents
- Introduction
- History
- Principles of fluoroscopy
- Comparison of fluoroscopy and radiography
- Purpose of fluoroscopy
- Components and their functions
- Types of fluoroscopic units
History
- In 1895, Wilhelm Roentgen noticed barium platinocyanide screens fluorescing, leading to the development of fluoroscopic images.
- Early fluoroscopes consisted of an x-ray tube and a fluorescent screen.
- In 1896, Thomas Edison discovered cadmium tungstate screens which produced brighter images.
- Zinc cadmium sulfide was later used as a screen material in fluoroscopes.
Old Type of Fluoroscopy
- Early fluoroscopes were cardboard funnels with a narrow end for the observer's eyes.
- The wide end had a thin cardboard sheet with a fluorescent metal layer inside.
- Examinations were conducted in darkened rooms due to the limited light produced by fluorescent screens.
- This resulted in high radiation exposure for the radiologist.
- Early fluoroscopes had insufficient image brightness, requiring the radiologist to adapt to the dark for 10 minutes before each procedure, sometimes using red adaptation goggles.
Modern Type of Fluoroscopy
- In the 1950s, x-ray image intensifiers were invented, enabling images to be viewed under normal lighting conditions.
- Image intensifier devices were developed to overcome the shortcomings of dim fluorescent screens, increasing image brightness and improving spatial and contrast resolution.
Fluoroscopy vs Radiography
- Fluoroscopy: Demonstrates the movement of objects, produces images immediately, requires precise positioning, and has a higher exposure for abdominal procedures (45 mGy/min).
- Radiography: Shows only stationary objects, images are processed, routine positioning is sufficient, and a single abdominal radiograph has a lower exposure (3 mGy/200msec).
Purpose of Fluoroscopy
- Evaluate the condition of coronary arteries during cardiac catheterization.
- Evaluate blood flow through an artery during angiography.
- Guide diagnostic and surgical procedures, such as catheter placement, needle insertion for biopsies, and fluid removal from body cavities.
- Evaluate the digestive tract for tumors, bleeding, and bowel obstructions
- Evaluate the large intestine with a barium enema or the urinary tract
- Evaluate a woman's reproductive organs (uterus and fallopian tubes).
- Assess fractured bones by realigning them and inserting pins.
Fluoroscopic Principles
- A study of moving body structures to obtain live x-ray images.
- X-rays pass through the patient and strike a fluorescent plate.
- The images are then transmitted to a television system to display the movement of body parts and structures.
Fluoroscopic Imaging Chain
- The system includes an x-ray generator, x-ray tube, collimator, x-ray image intensifier, optical coupling, monitor, and video camera.
Fluoroscopy Imaging Components
- X-ray tube, filters and collimation (similar to radiography)
- Image intensifier (converts dim images to bright, easily viewed images).
- Grid (improves image contrast by reducing scattered x-rays).
- Collimator (defines the area of interest for the x-ray beam).
- Filter (attenuates low-energy x-rays, improving image quality).
- Fluoroscopic couch (provides support, minimal x-ray attenuation, and tilting/positioning options).
X-Ray Generator
- Delivers power to the x-ray tube.
- Provides operator control of radiographic techniques (adjusting tube voltage, current, and exposure time).
- Similar to generators used for radiography but with additional circuitry for fluoroscopy, like automatic brightness control (ABC).
X-Ray Tube
- Converts electrical energy into x-ray beams.
- Consists of an anode and cathode placed in a vacuum envelope and shielded housing.
- Commonly using rotating anode tube.
Collimator
- Defines the area of interest for the x-ray beam.
- Can be round or rectangular to reduce exposed tissue volume and scatter, enhancing image contrast.
Filter
- Attenuates low-energy x-rays, improving image quality.
- Made of materials like aluminum and copper.
- Inherent filtration is part of the filter system.
Effect of Filter
- Filters affect the average energy and distribution of x-ray photons.
Fluoroscopic Couch
- Tables that support large patients.
- Minimizes x-ray attenuation.
- Designed for tilting and positioning.
- Primarily made from carbon fiber.
Grid
- Enhances image contrast by minimizing the amount of scattered x-rays reaching the image receptor.
- Typical grid ratios for fluoroscopy range from 6:1 to 10:1.
Image Intensifier (II)
- Converts x-rays into a visible light image, amplifying brightness by about 10,000 times.
- Consists of vacuum glass envelope, input layer, electronic lenses, and output layer.
Optical Coupling
- Distributes light from the image intensifier to a video camera and other image recording devices.
Television System
- A closed-circuit television (CCTV) system captures the image from the image intensifier, converts the image to a voltage signal, and transmits the image to a monitor for viewing.
Image Recording Devices
- Devices for recording images include spot film devices, film changers, photospot cameras, cine cameras and digital photospots, with selection based on clinical needs and image quality requirements.
Types of Fluoroscopic Units
- Conventional: X-ray tube and image intensifier are rigidly linked, with a couch designed to allow the patient to remain stationary while the tube/collimator moves.
- C-arm and U-arm: The x-ray tube and image intensifier unit can rotate around the patient, allowing for examinations in various planes without moving the patient.
Digital Fluoroscopic Unit
- Use of Charge-Coupled Device (CCD) or Flat Panel Detector (FPD) to generate images.
Fluoroscopic Couch Design
- Two main types of designs for the support table of fluoroscopy systems- under-couch and over-couch.
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Description
This quiz explores the principles, history, and components of fluoroscopy imaging systems. Students will learn to differentiate between fluoroscopy and radiographic imaging, and gain insight into the various types of fluoroscopic units. Test your understanding of this crucial imaging technique used in medical diagnostics.
