History of X-rays

on today's episode we're going to discuss a discovery that basically revolutionized the field of Medicine overnight over the following decades this same discovery also transformed fields as diverse as genetics and manufacturing and the most amazing part of all this is that the discovery was completely accidental join us for this next half hour as we discuss the history of the x-ray you I'm standing in front of the fountain building entrance to Halifax Medical Center in Daytona Beach Florida this historic building opened its doors for operation in 1928 and has been witness to the Great Depression multiple Wars and is strategically located approximately two miles from the world's most famous beach and a half a mile from the world-famous Daytona International Speedway but we're not here to soak up the Rays or watch the races but we're interested in is right through those doors so come on take a walk with me as you walk in the front entrance of the fountain Building of Halifax Medical Center a few feet in on the left is this place right here this is the Halifax radiology museum made possible by mr. Budd Hinkle who was the radiology manager from 1985 to 1995 and the great thing about Budd is he was a bit of a pack rat never threw anything away which is great for us she got a little bit of Americana behind us as I said previously Halifax opened its doors in 1928 complete with a radiology department some of the equipment behind me right now is the original equipment from that original radiology department and it's interesting to look at the radiology equipment from that error and compare it to what we have today x-rays are an intrinsic part of our modern society so much so that we take them for granted we've all been to the airport and had our luggage scanned during the security process in manufacturing x-rays are absolutely imperative to examine for defects in structural materials and airplane wings in years past a PhD scientists rosalind Franklin use x-ray diffraction information to examine the DNA molecule Watson and Crick use the same information to define the double helix structure of the DNA molecule in 1953 and of course there's medical x-rays we've all been to the hospital and had a chest or a skull radiograph no big deal but let me take you back over a hundred years ago the years 1896 and the newly discovered x-ray has now become a absolute phenomenon x-ray mania has gripped the world people couldn't wait to get their hands on this new technology you got to remember at the end of the 19th century electricity was first coming into the household you got machines that are doing work for us and all of a sudden there's this new ray this x-ray that can see through walls it can see through the human body and everybody wanted a piece of it and a lot of the early x-rays were for entertainment purposes as a matter of fact you could go up into the studios in New York that were called bone portrait studios and get a radiograph of your hand or your head or possibly even your chest get it framed and hang it up on the wall there was a lot of paranoia of course people were afraid that goggles at the Opera would have x-ray potential and you could look through a woman's skirt in the Opera so a lot of misconceptions about what the x-ray could actually do however there are a few level-headed individuals who recognize the advantages of this new discovery in the first American Medical x-ray was performed at Dartmouth College on February 3rd 1896 if you look at the image that's on the screen right now there's a picture memorializing that whole event there's a student sitting in the chair and there's two gentlemen on either side of the table the one on the right is a physicist who's actually timing the x-ray exposure the gentleman to the left was the patient's physician and this was the first radiographed very very primitive by today's standards but you can clearly see the patient had a fracture of his distal ulna now this is a classic you're not going to find these anymore this was called a handheld fluoroscope actually designed by Thomas Edison and when x-rays were first developed they were a bit of an enigma people were just enthralled x-ray mania one one to see a picture of their own hand and you could go mail-order by this little fluoroscope and they would send it to your home and if you could find someone to set up a Crookes tube for you and produce x-rays you could take a look at your own hand and basically what you would do is walk up to one of those tubes put your hand out raise the fluoroscope up to your eyes and actually see the bones of your own hand or you could look at your brother's face or your mom's foot it didn't matter it was great entertainment the problem of course is not only exposing your hand to a lot of excess of radiation your eyes were getting a pretty good dose also you're not going to find these anymore the man responsible for the discovery of x-rays was Professor William Conrad roentgen a physics professor at the University of warts Berg in wurtzburg Germany I took a trip to Worth's Berg myself a couple of years ago to check out where x-rays were actually discovered and looking at the picture that you're looking at right now I was able to recognize the building where professor Renkin had his office on the first floor and we get out of the car and we go up to one of the students there my wife who speaks fluent German asked somewhere professor renkins museum is and he had no idea and everyone we talked to had no idea where the physics department was or more specifically the roentgen museum was in the building we were standing in front of which was absolutely amazing to me here was a discovery that completely revolutionized the world medicine manufacturing as we discussed before and he couldn't tell us where the museum was but we eventually found it very unassuming small little room on the first floor of the Wartburg physics building in wurtzburg germany inside of that office inside that laboratory renkin was working with a small device called a Crookes tube the Crookes tube was a device that was essentially like a high powered light bulb it was completely evacuated of any air and on one side was the anode and on the other side was the cathode the cathode was connected to the negative pole of a DC voltage high voltage you're talking hundreds of thousands of volts of course the anode was then connected to the positive side of high voltage when this device was appropriately connected the tube itself would glow with his bluish green light and these were referred to as cathode rays there were theories at the time that these devices would actually produce other types of rage yet discovered and roentgen was interested in possibly looking at some of these other types of rays to that end he set up his experiment in his first floor laboratory in the Wartburg University Physics Department on November 8th of 1895 in this animation you see how we set that up all the way to the right he had a coil which would supply the high voltage to the crooks tube which was sitting right in the middle of the table this was connected again a cathode to the negative pole the anode to the positive pole once the tube was appropriately connected again it glowed that bluish green light a Renkin was trying to find other rays possibly admitted from the tube so he didn't want the bluish green light interfering with his experiment to that end he constructed a black box that would fit perfectly over the tube and block any of the light that possibly was emanated when the tube was turned on he went over to the laboratory light switch and he flipped it off went back over to the power supply and flipped that on and while he was looking around the box to see if there was any light that was emanating from the tube itself he's I caught a faint glow from a piece of paper that was sitting about eight feet away on another table he walked over to that piece of paper and looked down at the barium platinocyanide of phospho fluorescent material and saw that it was now glowing with this eerie greenish light and he wanted to see if the discharge from the tube was actually responsible for the glow so he went back over to the tube turned the power supply off the light from the barium platinocyanide paper went away looked it back on again the light came back so he was absolutely convinced that whatever was going on inside the tube was causing the paper eight feet away to glow being a great scientist he decided not to stop there he picked up that piece of barium platinocyanide paper and he put it right now to the tube and he started sticking objects between the tube itself covered in the black box and the piece of barium platinocyanide paper and he noticed stuff like paper really did nothing to block those rays whereas if he took a key a metallic key and put it between the tube in the paper it would completely block those rays eventually while holding an object between the tube and the piece of paper he saw the eerie outline of the bones of his hands he wasn't really sure if that's what he was actually seeing he thought it might have been some trick of the eye or or some kind of physics phenomenon that he had yet to really delineate and work out to that end he spent the next six weeks characterizing this new ray since he had never seen anything like it before he decided to call it X for the algebraic symbol of the unknown over the next six weeks Renkin purportedly took the first human radiograph of a hand which is shown here this is purportedly mrs. Renkin he brought her into the laboratory and he said honey sit down let me take a picture of your hand and this is supposed to be that radiograph showing her wedding ring there is no absolute proof that that was miss roentgen or that it was the first radiograph but that's how history has dubbed it and we consider this the first radiograph of a human hand after his six weeks of exquisite characterization of this new ray he gave his first public presentation just before Christmas of 1895 to the Wartburg physical Medical Society and during that presentation he brought up the renowned anatomist rudolf albert von kalakar to the front of the room and he sat him down under the crooks tube and he took this now famous radiograph a professor call occurs hand at the end of that presentation the crowd was absolutely amazed they had never seen anything like it professor van calico renowned anatomist thought that this was going to revolutionize mankind the field of medicine and immediately declared that the new ray should be labeled Renkin in honor of the discoverer what we're looking at now is a classic piece of equipment and if you had a father or mother or possibly a grandfather a grandmother who lived in the 1940s they probably recognized this particular piece of equipment you would find it just about any shoe store that you went to and this was great because what you would do as a kid you'd come up and you'd step up on this platform and you would stick your feet right through the little hole that you have right in the front here and if you look at the top of the Machine there's basically three viewports one two three one for you one for your mom and probably one for the salesman is trying to sell you a new pair of shoes and as you're standing here they turn on a radiation source underneath of your feet and it would show you the bones of your feet relative to the shoe and the salesman could say oh they fit perfectly look how those bones fit right inside that shoe great great stuff the kids loved it they'd stop on their way home from school and stop at the local lush to store just to see the bones of their feet of course we finally realized that this over exposure to radiation is probably not a good thing and this particular device was discontinued by the 1960s so how was renkins Crookes tube able to produce x-rays you got to remember an electron is a negatively charged particles so the electrons would fly from the negative side akkad across the tube towards the positively charged anode okay opposites attract so when a negatively charged electron is going to want to go towards the positively charged anode these electrons would pick up so much force because this was a a high-voltage power supply so the potential was tremendous and they would fly across so fast that often they would bypass the anode and actually hit the back side of the glass with this particular configuration once those electrons hit that glass they gave up all that energy just like a bullet being fired from a gun you shoot the bullet from the gun it comes out the end if it's a lead bullet it hits something hard and all the energy in that bullet basically is dissipated at once it heats the LED up and the lead becomes flat just like the bullet the electron gives up its energy most of the energy that the electron gives up is in the form of heat approximately 1% or less of the electrons when they give up their energy they give it up all at once instead of producing heat they actually produce an x-ray and like I said very very inefficient device most of the energy is dissipated in the form of heat 99% but every now and then one of these electrons will hit the right way and produce an x-ray this process is called bream strolling and bream strolling is German for breaking radiation now the energy of the electron depends tremendously on the voltage potential between the two poles so the higher the voltage the more energetic the x-rays coming out of the tube and that's the way we adjust the power of the x-ray tube even today you increase the voltage the x-ray is coming out or more powerful so we'll be able to penetrate more but the crooks tube itself is a very inefficient way to produce x-rays if you look at it again the anode was actually positioned off-center at the base of the tube so when the x-rays were produced they basically bounced off in all directions the two produced x-rays all over the place if you look at this picture here this actually shows a couple of scientists or average guys in the physics department using a Crookes tube and both looking at their hand one gentleman is looking at his hand on a standard radiographic plate the other one has got a handheld fluoroscope and he's holding it up and looking at his hand in front of the crooks tube and the reason they're able to do that is because the crooks to basically bathe the whole room in x-ray light okay it was unfocused it didn't go in any particular direction the problem with that is if you're trying to make an x-ray you don't an x-ray image you don't have a lot of the x-rays available to take a picture if you look at this picture an x-ray of a foot in a shoe this picture was fabulous it showed up in a popular journal right around the turn of the century people always like to see these new radiographic images but it took almost 20 minutes to make this single image so the person that posed for this radiograph had to sit still for 20 minutes to make this simple photograph the first major development for the improvement in the x-ray tube from the basic cathode ray tube or crooks tube was the movement of the anode from an off centered position on the ball the side of the tube - directly across from the cathode itself that way all the electrons that are being admitted from the cathode go directly into the anode the anode was then beveled and that bevel basically focused the x-rays in one direction so instead of having x-rays produced all over the room now you had x-rays that were essentially coming out in one direction and because they were coming out in one direction you could significantly reduce the amount of time that it needed to produce a single radiograph the next major of advancement was on the cathode side of the tube and on the cathode side we went from a single basic disc to a heated element just like the heated element inside of a light and when you turn on the light bulb you'll notice that the filament glows with this reddish glow eventually producing a tremendous amount of light and lighting up the room but the glowing element actually boils electrons off of the metal and they kind of rotate or cloud around the filament itself this is called thermionic emission the hotter you make that particular element the more these electrons are boiled off so once you heat that element aw you will see the electrons boiling around and when you connect the tube to the high-voltage power source you will have more electrons available for x-ray production in summary even on a modern x-ray tube the adjustable settings or the voltage or kVp and the current or mas increasing the voltage increases the average strength or power of each individual x-ray coming out of the tube increasing the current makes the cathode filament hotter boils more electrons off and allows the tube to produce more x-rays over a set time period the radiology technologist is trained to adjust these settings and maximize image quality for each patient depending on the body part being imaged and the overall size or thickness of the patient themselves the final design change involved the anode if you look at a old tube like the one you see behind me here with the angled anode and the element for the heated element for the cathode over time this constant bombardment of these high-energy electrons would cause the anode to basically pit and if that got bad enough then the x-rays would start spreading out they wouldn't be focused in one direction and the anode would be considered blown the whole tube would be considered bad the final design involved a rotating anode so instead of depositing all of that heat energy right into one point into that angled anode you basically had a disc that was angled and spun around to deposit that heat and and basically spread out the heat energy over a wider area and have the tube last longer and longer we couldn't do our modern imaging without some kind of rotating anode because the energy that's produced in the CT scan is so tremendous it would completely melt any known metals that we have so absolutely imperative and when you go and get an x-ray done the first thing you'll hear is a little motor startup and that little rotating motor is the anode that's spinning around in preparation for the production of x-rays now it's interesting I've described to you what an anode is and what a cathode is and what an x-ray tube actually is itself if you look at a cathode ray tube or the tube that was inside your old TV set it's basically an electron gun and the electrons just like in the x-ray tube are fired from the back of the gun and then they're shot onto a fossil fluorescent screen just like roentgens screen that he was using in his experiment and this is what Purdue the picture on the TV screen and you can remember your mom or your dad telling you back away from that TV there's radiation coming out of that thing they're absolutely right it's basically an x-ray tube and the x-ray radiation that's produced is minimal but there is a finite amount of x-rays that are produced from the front of a standard TV tube with the new LCD screens or the new technologies that we have to make TVs that's not an issue anymore but the older TVs if you still have a tube if you sit close enough you'll actually get some x-ray exposure we've looked at the process of making an x-ray from high-speed electrons the next step is to make an actual radiographic image x-rays are part of the electromagnetic spectrum just like the light that allows you to see this image on the screen right now in fact what we humans refer to as colors actually make up a very small portion of that spectrum moving from one end to the other we start off with low energy waves like AM radio the visible portion of the spectrum is actually a small slice almost right in the center at the far right end there are the high-energy x-rays and gamma rays while these rays can cast shadows just like visible light their higher energies make them capable of passing through some objects as well our bodies are made up of many tissues that can block these rays to a varying degree depending on their thickness and density as seen on this image the air-filled lungs block very little x-rays and allow most of the energy to pass through and expose the sheet of film the heart on the other hand is a dense muscle and blocks more x-rays than the air-filled lungs but less x-rays than the hard calcium-rich bones of the chest putting these all together an x-ray exposure allows us to produce a composite anatomic image of x-ray shadows that we refer to as a radiograph with a firm knowledge of normal radiographic anatomy we can use x-ray images to actually diagnose disease processes like this pneumonia in the right lung Renken died in 1923 despite urging from friends and family he never pursued patent protection on x-rays he felt that any scientific discovery needed to stay with the scientific community to be thoroughly investigated and developed by future generations his generosity to humankind is absolutely immeasurable in terms of lives saved both in medicine and industry from a scientific standpoint x-rays have provided us a clearer understanding of the world around us from genetics material science and even the universe itself pretty amazing credits for a chance discovery in a small German laboratory in November of 1895 thanks for watching you you you

Channel: Doctor Klioze

Views: 267,766

Keywords: X-ray (Namesake), Physics (Idea), Wilhelm Röntgen (Inventor), Crookes Tube, anode, Cathode Ray Tube (Invention), Radiology (Medical Specialty), Radiologic Technologist (Occupation), shoe fitting machine, scalelabs, scalelab network, scalelab, scalelabnetwork

Id: fHUzVqoDnts

Length: 24min 20sec (1460 seconds)

Published: Sat Dec 07 2013