Quiz On TV Monitoring In Fluoroscopic Imaging

The correct answer is thermonic emission. In a television camera, the electron gun is a heated filament that emits electrons through a process called thermonic emission. When the filament is heated, it releases electrons, which are then accelerated and focused to form an electron beam. This electron beam is used to scan the image on the camera's target, converting it into an electrical signal that can be transmitted and displayed on a television screen.

In fluoroscopy, high kVp (kilovoltage peak) and low mAs (milliamperes-seconds) are preferred. This is because high kVp allows for better penetration of the X-rays through the patient's body, resulting in clearer and more detailed images. On the other hand, low mAs reduces the amount of radiation exposure to the patient, which is important for safety reasons. Therefore, the combination of high kVp and low mAs provides optimal image quality while minimizing radiation dose.

During fluoroscopy, the x-ray tube is operated at a current lower than 5 milliamperes (MA). This is because fluoroscopy involves continuous imaging, which requires a lower radiation dose compared to traditional x-ray imaging. Operating the x-ray tube at a lower current helps to minimize the radiation exposure to the patient and the healthcare provider while still producing clear and accurate real-time images.

The photocathode is a material that, when exposed to light, releases electrons through the photoelectric effect. This phenomenon occurs when photons from the incident light strike the photocathode and transfer their energy to the electrons, causing them to be emitted. Therefore, the correct answer is electrons.

When an x-ray interacts with the input phosphor, its energy is converted into visible light. This is because the input phosphor is made of a material that emits visible light when it absorbs x-ray radiation. This visible light can then be further amplified and converted into an electronic signal to produce an image on a screen or film. The conversion of x-ray energy into visible light is an essential step in the process of capturing and visualizing x-ray images.

The term "brightness gain" refers to the ability of the image-intensifier tube to amplify the level of illumination in an image. This means that the image-intensifier tube can increase the brightness or light intensity of the image, making it more visible and clearer to the viewer. This is a crucial feature in devices such as night vision goggles or cameras, where enhancing the brightness of the image is necessary for improved visibility in low-light conditions.

Cones are primarily used for daylight vision. Cones are photoreceptor cells in the retina of the eye that are responsible for color vision and visual acuity in bright light conditions. They are most active during daylight and provide detailed and colored vision. In contrast, rods, another type of photoreceptor cells, are more sensitive to dim light and are responsible for night vision. Therefore, cones are the correct answer as they are specifically designed for daylight vision.

A fluoroscope is a medical imaging device that aids radiologists in viewing dynamic studies. It is used to visualize real-time images of the internal structures of a patient's body, such as the movement of organs or the flow of contrast agents. The fluoroscope uses X-ray technology and a fluorescent screen to produce these images, allowing the radiologist to observe and analyze the patient's condition in real-time. This tool is particularly useful for procedures such as angiography, where the flow of blood through blood vessels needs to be monitored.

The image-intensifier tube is the electronic device that receives the remnant x-ray beam and converts it into light. It also increases the intensity of the light, allowing for a brighter and clearer image to be displayed. This technology is commonly used in medical imaging, such as fluoroscopy, to enhance the visibility of the x-ray image for diagnostic purposes.

The correct answer is vidicon & plumbicon. These are two types of TV camera tubes commonly used for television monitoring fluoroscopy. The vidicon tube is a type of camera tube that converts optical images into electrical signals, while the plumbicon tube is another type of camera tube that is more sensitive and produces higher quality images. These tubes are specifically designed for fluoroscopy, which is a medical imaging technique that uses continuous X-ray beams to create real-time images of the internal structures of a patient.

The fovea centralis is a small area located in the center of the retina. It is responsible for our central vision and is densely packed with cones, which are photoreceptor cells that are sensitive to color and detail. This concentration of cones allows for sharp and detailed vision in well-lit conditions. In contrast, rods, which are responsible for vision in dim light situations, are located in the periphery of the retina.

The correct answer for this question is Thomas Edison. Thomas Edison is credited with inventing the fluoroscope in 1896. The fluoroscope is a device that uses X-rays to produce real-time images of the internal structures of the body. Edison's invention revolutionized medical imaging and had a significant impact on the field of radiology.

Dark adapting refers to the process of allowing the eyes to adjust to low light conditions in order to improve visibility in the dark. Wearing red goggles under normal illumination for up to thirty minutes prior to fluoroscopic examinations helps the eyes adapt to the darkness of the fluoroscopy room, allowing the radiologist to better visualize the images produced by the fluoroscope. This technique is commonly used in radiology to enhance image quality and reduce eye strain during fluoroscopic procedures.

Vignetting refers to the reduction in brightness at the periphery of an image. In the context of the given question, the portion of the image resulting from the periphery of the input phosphor is inherently unfocused and suffers from vignetting, leading to a reduction in brightness. Therefore, the correct answer is vignetting.

When high energy electrons interact with the output phosphor, a considerable amount of light is produced. The interaction causes the electrons to excite the atoms in the phosphor, leading to the emission of photons. These photons then contribute to the production of light, which is observable on the fluorescent screen.

The video signal of the TV camera is directly proportional to the intensity of light. This means that as the intensity of light increases, the video signal also increases. This makes sense because the camera needs sufficient light to capture a clear and bright image. The intensity of light determines the amount of light that reaches the camera's sensor, which in turn affects the strength of the video signal. Therefore, a higher intensity of light will result in a stronger video signal.

The iris is the part of the human eye that behaves like the diaphragm of a photographic camera to control the amount of light. The iris is responsible for regulating the size of the pupil, which in turn controls the amount of light that enters the eye. This mechanism helps to adjust the amount of light reaching the retina, ensuring optimal vision in varying lighting conditions.

Minification gain refers to the reduction in size of the image produced by an imaging system. In the context of this question, the ratio of the number of light photons at the output phosphor to the number at the input phosphor defines the minification gain. This means that it determines the extent to which the image is reduced in size.

Photoemission refers to the process of electron emission from a material when it is exposed to light or other electromagnetic radiation. This phenomenon occurs when photons from the incident light transfer energy to the electrons in the material, causing them to be ejected. The emitted electrons are called photoelectrons. Therefore, the correct answer is photoemission.

The correct answer is "the time when the cine film is in position for exposure". This is because in synchronized cine systems, the x-ray tube is energized only during the specific time when the cine film is in position for exposure. This ensures that the x-ray tube is not unnecessarily energized and reduces radiation exposure to both the patient and the medical staff.

The fluorescent screen is the specific component of the television monitor that converts the video signal into a visible light image. The fluorescent screen is located inside the picture tube and it emits light when it is struck by electrons. This light forms the image that is displayed on the television screen.

The principal advantage of image-intensified fluoroscopy over conventional fluoroscopy is the increased visuality because of the illumination of cone vision. This means that image-intensified fluoroscopy provides a clearer and more detailed visualization of the dynamic images compared to conventional fluoroscopy. The illumination of cone vision enhances the visibility of the images, making it easier for the healthcare professional to accurately diagnose and treat the patient.

The glass envelope in a television tube performs a similar function as the filament in the cathode of the x-ray tube. The glass envelope provides a protective casing for the internal components of the television tube, just like the filament provides a protective casing for the cathode in the x-ray tube. Both the glass envelope and the filament play a crucial role in maintaining the integrity and functionality of their respective tubes.

The correct answer is "no audio & no channel selection." This is because closed circuit television fluoroscopy is used for medical imaging and does not require sound or the ability to change channels. In contrast, a home television set is used for entertainment purposes and typically has audio capabilities and the option to select different channels.

Photopic vision refers to the visual perception that occurs under high levels of illumination, specifically during daylight conditions. It is the ability of the human eye to perceive color and detail in bright light. This type of vision is mediated by the cone cells in the retina, which are responsible for color vision and high visual acuity. Photopic vision allows for clear and detailed vision, making it ideal for activities that require color discrimination and fine visual detail in well-lit environments.

Two interlaced television fields combine to form one complete television frame. In interlaced video, each frame is divided into two fields, with one field containing the odd lines and the other field containing the even lines. These fields are then displayed alternately on the screen, resulting in a complete frame. Therefore, the correct answer is "tv frame."

The spot film is generally positioned between the patient and the II (image intensifier). This placement allows for capturing a more focused image of a specific area of interest in the patient's body. The II intensifies the image, making it more visible and clear for diagnostic purposes.

The correct answer is "picture tube" because the heart of a TV monitor refers to the main component that produces the visual display. The picture tube, also known as a cathode ray tube (CRT), is responsible for generating the images on the screen by using an electron beam to excite phosphor dots on the inside of the tube. This creates the colored pixels that form the television picture. The rotating anode, fiber optic, and vidicon are not directly related to the visual display of a TV monitor, making them incorrect choices.

When coupling the television camera to the image intensifier using fiber optics, the principal disadvantage is that a spot film camera cannot be used. This means that it is not possible to capture a still image or a single frame from the video feed. Instead, the television camera captures a dynamic image, which is continuously changing and cannot be paused or frozen like a spot film picture taken with a spot film camera.

The camera lens is the most critical component in optically coupling the image intensifier to a spot film camera. This is because the lens determines the focus, clarity, and quality of the image that is captured by the camera. Without a high-quality lens, the image intensifier may not be able to properly transmit the image to the camera, resulting in a poor or distorted final image on the spot film. Therefore, the camera lens plays a crucial role in ensuring that the image intensifier and spot film camera work together effectively.

The weakest link to image-intensified fluoroscopy is the TV monitor. This is because the TV monitor is responsible for displaying the fluoroscopic images to the user. If the monitor is of poor quality or has low resolution, it can affect the clarity and accuracy of the images, making it difficult for the user to interpret the fluoroscopic procedure. Additionally, if the monitor is not properly calibrated or maintained, it may introduce artifacts or distortions in the images, further compromising the accuracy of the procedure. Therefore, a high-quality and well-maintained TV monitor is crucial for effective image-intensified fluoroscopy.

Image-intensified fluoroscopy is visualized under illumination levels ranging from 100 to 1000 lux. This means that the fluoroscopy image is viewed under a moderate level of brightness, which allows for clear visualization of the image while still maintaining a comfortable viewing experience. The range of illumination levels ensures that the image is not too dim or too bright, providing optimal visibility for the procedure being performed.

The brightness gain of most image-intensifiers refers to the amplification of the incoming light. The given answer range of 3000-50000 indicates that the image-intensifiers can amplify the brightness of the incoming light by a factor of 3000 to 50000 times. This wide range suggests that different image-intensifiers may have varying levels of brightness gain, but they all fall within this range.

The correct answer is that only the central region of the IP is used. In image-intensified fluoroscopy, the image is magnified by focusing on the central region of the image intensifier plate (IP), which contains the highest resolution. By only using this central region, the spatial resolution of the image is improved. This allows for better visualization of small details and structures in the image.

The preferred method of viewing the fluoroscopic image is the vidicon. The repetition of "vidicon" in the options suggests that it is the correct answer. However, the inclusion of "vedicon" as an option may cause confusion, as it is similar to "vidicon" but spelled differently. Therefore, it is important to choose "vidicon" as the correct answer.

The numeric values in a 25ll7ll12 cm tri-focus image-intensifier tube refer to the diameter of the input phosphor of the II tube.

Using a larger film format in the camera results in better image quality. However, it also leads to increased exposure when using the camera in fluoroscopy.

TV camera tubes are coupled to the image intensifier using fiber optics and lens coupling. Fiber optics allow for the transmission of light signals from the camera tubes to the image intensifier, ensuring efficient and accurate transfer of the image. Lens coupling is also used to align and focus the light signals, further enhancing the quality of the image. This combination of fiber optics and lens coupling enables the camera tubes to effectively capture and transfer the image to the image intensifier.

Modern fluoroscopic equipment allows the radiologist to select an image brightness level by adjusting either the kvp (kilovoltage peak) or the ma (milliamperage). The kvp determines the energy of the X-ray beam, which affects the contrast of the image. The ma controls the amount of X-ray photons produced, which affects the overall brightness of the image. Therefore, by adjusting either the kvp or the ma, the radiologist can achieve the desired image brightness level.

The brightness of the fluoroscopic image is primarily dependent on the anatomic structure being studied, as well as the technical factors of kvp (kilovolt peak) and ma (milliamperage). These factors determine the amount of radiation used and the quality of the image produced. The anatomic structure being studied affects the amount of radiation that is absorbed or scattered, which in turn affects the brightness of the image. Adjusting the kvp and ma settings can further control the brightness and contrast of the image.