In a videofluoroscopy exam, the aim is to capture the highest image quality possible while being responsible about limiting unnecessary radiation exposure, however there are many factors that can influence this. Since 2007, questions regarding optimal image acquisition rate have been the focus of research conducted Professor Martin-Harris, Professor Bonilha, Professor Martino, and Professor Steele. In order to understand how technical considerations can influence the quality of data and information acquired during the videofluoroscopic swallowing assessment, it is important to understand the components involved in the generating, viewing, recording, and reviewing processes. A range of factors come into play at every stage of the exam. In fact, even when people think they are acquiring 30 frames per second, the truth is often something else altogether.<\/p>\n\n\n\n
A very important issue to understand is the difference\nbetween continuous and pulsed radiation. \nHistorically, traditional fluoroscopy was typically continuous; meaning\nthat when the beam was on, it produced a steady stream of radiation. New generation fluoroscopy offers an\nalternative, where the radiation beam can be delivered via small packets called\npulses. The number of pulses that are\ndelivered per second can be specified, and deciding on what pulse rate to use requires\nconsideration.<\/p>\n\n\n\n
An important terminological issue to parse out is the\ndifference between pulse rate<\/em><\/strong> and frame rate<\/em><\/strong>.<\/p>\n\n\n\n Historically, the term frame rate was used generically to\ndescribe the number of images that were generated per second in a\nvideofluoroscopy. In the case of\ncontinuous fluoroscopy, there is no meaningful distinction between the image\noutput rate of the fluoroscope and the rate of image display on the monitor or on\nthe recording system. However, with\npulsed radiation, the distinction becomes meaningful. When using the term pulse\nrate, we are referring to the output of the fluoroscope, specifically the\nnumber of bursts of radiation\nthat are emitted per second.<\/p>\n\n\n\n When we use the term frame rate, we will be speaking more\nspecifically about the recording end of the system, and referring to the number\nof images that are recorded\/stored\/archived per second on that system. The fact that these two things can be\ndifferent introduces options that can lead to possible confusion and impact the\namount of information that is available to the clinician when reviewing\nvideofluoroscopy. <\/p>\n\n\n\n Historically, continuous fluoroscopy would create a\ncontinuous stream of information that was captured on the recording end as 30 images\nper second. With the development of pulsed\nfluoroscopy, the same effect (i.e., a recording containing 30 images per second)\ncan be achieved using a pulse\nrate of 30 pulses per second, and a capture rate of 30 frames per second, provided that the\ncapture system is properly synchronized with the fluoroscope. A lower pulse rate of 15 per second involves less radiation exposure than\na pulse rate of 30 pulses per second, assuming a similar dose per pulse.\nHowever, if this pulsed output is recorded at a frequency of 30 frames per\nsecond, the resulting output will consist of 15 pairs of images. <\/p>\n\n\n\n There are several ways to record videofluoroscopy exams such as PACS, DVD recorders, and computers running proprietary capture software. It is also important to consider the chain of processing that the information passes through. The more links in the chain, the more susceptible the data is to being compromised, and the more settings to confirm to ensure that the quality of the final images is adequate for review. Mismatches in the rate of information being generated and being captured can result in interpolated or duplicate images in the final recorded product. <\/p>\n\n\n\n Acquisition of Videofluoroscopic Swallowing Studies In a videofluoroscopy exam, the aim is to capture the highest image quality possible while being responsible about limiting unnecessary radiation exposure, however there are many factors that can influence this. Since 2007, questions regarding optimal image acquisition rate have been the focus of research conducted Professor Martin-Harris, Professor Bonilha, … <\/p>\nRecorded Images per Second<\/h4>\n\n\n\n
References on this topic<\/h4>\n\n\n\n
\nFluoroscopy Safety 8-20-13.pdf<\/li>