hey guys i'm brian and this is luca from how ideology works we're going to talk about film versus cr versus dr luca what do you prefer digital or film let's boom that's right a lot of kids these days will just say what's film because we don't have film cameras around anymore and we're going to talk about for radiology and radiography specifically the film versus cr which is computed radiography versus dr which is digital radiography coming up let's get into our comparison now of film versus cr versus dr and one of the big advantages is dynamic range we have a video where we described dynamic range before but it's basically the ability to make a good image even over a wide range of radiation dose exposures since we're applying the radiation dose that the image receptor sees and on this axis we're plotting for instance the film optical density or the digital number in the crdr system the idea here is there's a region here where film is nice and well behaved and if you have an exposure in that region you're going to get a good nice proper exposure and we show that here where we have a hand and a arm that are properly exposed so you can see the bones within them but nothing is saturated and then you can see in this region right here there's actually not enough x-rays for the film to be properly exposed so it actually ends up being dark and it ends up being the case that some of the anatomy are not actually well visualized at all so even if you were to change the window width and window level settings you won't be able to recover proper image quality that that would be if you digitize that film but obviously the film itself would not be able to change um the brightness inherently that's the case of underexposure and then the case of overexposure is actually the reverse and it's shown here where in a lot of the high attenuation areas like in the dense bones those become saturated and you lose your ability to visualize the details within those bones so the real benefit of digital imaging which includes both cr and dr is the ability over a wide dynamic range to visualize the images to visualize them properly it's not limited by a narrow exposure range of film we're going to be talking about both advantages and disadvantages actually of this wider dynamic range film is an entry system and a lot of areas it's still going to be the standard because a lot of areas in the world are not affluent enough to afford for cr and dr systems and film still can produce good image quality and do a good diagnostic job so there's nothing wrong with using film cr is then the step up from that wherein you can use cr a lot of times as a relatively direct replacement for your film systems you still have the same cassette and you are using that cassette to digitize based on a phosphor within the cassette we have more details on that one see the link below for our cr video then dr there's a couple different ways dr works but it's the most expensive of the technologies but you're going to also see it has other benefits as far as the dose image quality and speed we're going to get to those but it is the most expensive and it's typically most often working with a thin film transistor behind a scintillator and we have another video check the link below on that for how dr works so we know now that as far as expense dr is going to be the most expensive but as far as speed dr is definitely going to win the race as far as speed there's been a number of studies here's one example study which showed for a single technologist using standard traditional cr techniques uh standard exam was taking 14 minutes for a standard cr and was taking eight minutes with the dr technology this is because the image can be acquired directly there's not the need to clear the panel there's other ways obviously around it with newer cr technologies or having two technologists work where one's taking the image and the other ones digitizing it but in general dr is going to be the fastest way to make the images and that's a big advantage for dr especially in the case of high throughput sites then finally radiation dose like we talked about in that last case of the dynamic range the cr and dr allow us to make images over a significant dynamic range here so cr and dr we can now make good images over a much bigger dynamic range or a much wider change in the radiation dose to the image receptor and in the case that we under expose even if we have cr the radiologist isn't going to be happy because the image that they get is going to be really noisy so they're going to give a thumbs down for the case of under underexposure then for the case of proper exposure the radiologist is going to give a thumbs up but with cr we can now make relatively good images here even with higher radiation dose than we need from a standpoint of the noise in the image but the image is going to look well it's going to be readable so the radiologist if just looking at the image is going to give this a thumbs up as well so there's a range in here where the patient could be overdosed on cr systems if not properly accounted for so in the case that we have dose conscious staff including the radiologists the physicists the technologists again we know we can't make a good diagnosis when the image is too noisy so that's going to be a thumbs down but there's also going to be a thumbs down for this case we need to monitor this by monitoring our dose levels there's also going to be a thumbs down for this case of relatively higher exposure where the image now looks good on a cr system but it's still relatively higher exposure so we want to shoot for this middle range right here on a cr system this is easier to actually get the right values on the dr system because a dr system in comparison with the cr system can have more advanced automated exposure controls because the whole panel can be read out so you can for instance get a histogram of what the whole panel says and use that kind of rich information in order to perform what's called the automatic exposure control and determine what the proper radiation dose for that exposure is with film and with cr it's more difficult to do proper automated exposure control so in general also the technology behind the dr systems is a little bit more dose efficient so from that perspective the dr is going to win as far as the dose efficiency and if done properly cr can be on the same order as film but if done improperly cr can actually end up leading to higher radiation dose than even film so make sure next to dig into the details of cr and dr we're going to have a playlist that includes the cr and dr detailed videos of how they work from a physics perspective [Music]