okay students here we go into skull positioning I know how excited you are after learning all this skull Anatomy so the things to consider is the size and shape of the skull um the general body position of the patient and we need to take a look at how clean everything is in addition and protecting our patients of course so um we are going to talk about where the gabella inner canthus outer canthus Nason info orbital margin the canthon the Goon the mental point the E are um are arular Point um and the tea which is top of the ear attachment so when we look at this diagram here first thing we're going to start off with is the mid sagittal plane so this is your mid sagittal plane it cuts the body into right and left halves on the skull so when we look at the mid sagittal plane right down the middle we have the Inner pupilary Line here so the two big things that we're going to talk about when we're positioning the skull the facial Bones the mandible anything is your MSP which is your mid sagittal plane and your IPL inter pupillary line so here IPL so we're looking for tilt and rotation from these two lines here so your gell um and I consider the gabella like right between the eyebrows and the Nason is kind of where this cross is right here so we have the gabella and the Nason so we have the inner canthus with the outer canthus here's your Nason right there you have your canthon right where your nose and uh your upper skin comes in to where it starts to head out towards your nose that's your canthon you have your mental point which is your uh the point of your chin the angle of your mandible which we're going to call the Goon and you have your infraorbital margin right down here so I ml so is going to be a line that we're going to use quite a bit along with your autoc canthus which is your oml so um it's important that you know where your outer canthus is your infraorbital margin is your goon mental point a canthon Nason gabella inner canthus outer canthus so the lines that we're going to talk about is the orbital U meatal line so the oml is from the outer canthus to the E your infraorbital meatal line and as you can assume it's just below the orbital meatal line and that's your I ML and that's from your infraorbital margin to your eam then you have your gabello mial line which is your gml and it's from your gabella to your e you have your IPL which is your inner pupilary line so it's perpendicular line between the um pupus of your eyes there's the acantho mial line so the AMF which from the canthon to the eam so your eam is your base and then it angles to whatever an anatomical part so the canthon so it goes from your e to your canthon you have your mental meatal line so that's your MML is the PO um from mental point to the chin so so uh to your am sorry so here if we look here we have the gabella Veer line which comes straight down from the gabella to your canthon so this line is going to be important when we're looking at your smv position um I know all these acronyms hang in there you're going to get the lingo down so here is your eam so external acoustic meatus so with your external acoustic meatus we're going to your gabella mial line so your uh gml so right here then we have your orbital mial line and you can see here it goes to your outer canthus and you can see it's about 7° 8° and then 7 degre to your info orbital meatal line so here's your um I ml just below that um it's okay if you consider this 7° it's 8° but um for E's sake we consider this about 7 to 8 degre so um here we're going down to your AML which is your eanl mial line and this is your canthon right here so gabella Nason is right here then you have your canthon and your mental point so then you have your um eam to your AML to your canthon which is your AML your canthal meatal line and then you have your MML which is your mental meatal line so as you can see this is about 7° 7° so we've got a swing in there so you're going to have to be able to calculate the difference if you can't hit your oml and you're supposed to be at your oml you're going to have to figure figure out what the distance is and try to figure out how to correct the angle okay so this is your midsagittal plane here on a patient that's prone so you can see your midsagittal plane has to be straight and you can see here with the patient laying Supine and this is your midsagittal plane all right so um based on skull type and shape we have to adjust the patient so that we can get our CR entering and going through the body the way that we want it to so um the patient typically for any skull work we want them up right so there are times where the patient's on a backboard or they can't sit up they're too unstable um and we're going to do it supine but if you have an option you're going to want to do everything upright um it's important to know your body type that you're dealing with with your patient and I'll show you why so oh awesome I love it when it slides in like that so when we're looking at the table if we have someone with really big shoulders or really narrow shoulders the patient's going to kind of roll into weird positions so this is just using the table when you're positioning for a skull and this is upright just so you guys know the difference and you have your hyposthenic and athenic patients need support at the chest to elevate the cervical spine so help prevents the downward tilt of your MSP so your MSP always needs to be straight with your IPL needs to be straight in addition so hypersthenic patients require Lucent support under the head so it helps um prevent the upward tilt of the MSP and I'll show you what I mean here in just a minute so review again here is the MSP and here's the IPL and we want to make sure in either table or upright bies that we are completely straight that is really important when we do your um lab practical we're going to check and see that your MSP and IPL are straight so that's the biggest thing so if you see here you have your hyposthenic patient and you can see how your MSP is angled so that's not good we have to fix that the easiest way to fix it is put a bolster under their chest and that brings their head up so that your MSP will be nice and straight and you can see here for hyperic patients or patients that are very big and you can see how your MSP is tilted the other way and you've got to fix that by putting a sponge under does this cause magnification yes it does but you know what you have to get that MSP straight so it's really important get that MSP and IPL in the uh perpendicular or parallel plane so here you want to make sure that you would you bolster this up so that it's nice and straight so you can see that right there so big difference don't go off of the nose a lot of people have crooked noses and it will um definitely screw you up so make sure that you're looking at the whole bony structure from the gabella down to the mental um point so you can see here this is nice and straight and you've got the IPL straight in addition okay so here on hyper stanic patients you're going to have a problem getting your oml in the proper line so you can also put a sponge under to get the oml nice and straight so this is usually where you want to be sometimes times the patient falls right into position for a view um because they have a lot of fat behind their back which is causing their head to rock back which ends up being perfect so for like a Waters um it works out nicely all right so you need to make sure that the hair and skin the face um are they're naturally oily so you need to make sure you clean everything really well um especially the patient going to be touching the board it's really gross you're going to be touching people's faces and hair so you need to make sure that you wash your hands and make sure that you're nice and clean too uh protect the patient so you're going to want to go ahead and cumate number one that's the first thing we want to do you can put a thyroid shield on patients um I've done that before quite a bit I'll bring a shield right up under their chin to cover the breasts on females also so I'll cover the thyroid and the breasts in one shot all right make sure the patient removes earrings rubber bands braids ponytails Dentures partials hearing aids if the Dentures are all plastic they're usually fine a lot of the times they'll have a piece of metal in there that they didn't know about you'll see it um they need to remove their hearing aids they need take out all jewelry jewelry um then you take out any wigs or hair pieces hair pins barrettes anything prosthetic eyes if they're glass it's fine um if they're not glass you're going to have to ask them to remove them so that is quite an experience of how to do that a few times and just gives me the willies all right so these are the projections of the cranium we have the lateral and then we're going to talk about different ways that you can get the lateral projection so don't freak out the centering is exactly the same and the MSP and IPL and all that is exactly the same it's just different ways to get it okay there's the PA there's PA axial which is called Codwell there's the AP there's the AP axial there's the AP axial town method there's the PA axial hos method and there's the cemento um Verte veral vertical smv so we just call it the smv and that we use for the cranial base to see if there's any fractures of the cranial floor all right so lateral projection we want the patient typically upright we want to see if there's air fluid levels within the skull okay so typically we do it upright but you can do it recant um anterior oblique also so the MSP of the head is parallel to the image receptor the IPL is perpendicular so you need to know which way which one's going and you want your I ml parallel to the transverse axis of the cassette so and I'll show you what I mean by that so the CR is coming in perpendicular to the IR the CR enters 2 in superior to the eam and then you're going to colate on a 10x 12 cassette so this is with the patient in the dorsal decubitus you're going to elevate the head or support it so um uh you have the patient with the MSP and the IPL straight so the MSP of the head is vertical the IPL is perpendicular the I ml is parallel to the transverse axis of the cassette um the CR is horizontal and perpendicular to the center of the IR and you're going to enter 2 in superior to the eam so 2 in Superior to to the eam M for a lateral skull you're on a 10x 12 cassette okay so this here is for supine we come to an oblique so Elevate the head you're going to turn it towards the side of Interest you're going to um have the CR coming in perpendicular 2 in superior to the E am and you're going to cumate to 10 x 12 so there's multiple ways to get this view you need to figure out what is best for the patient so here is an upright and as you can see here we've got the um MSP here uh parallel to the IR you have your IPL perpendicular right it's coming into it nice and straight perpendicular you are centered 2 in superior to the eam 2 in superior to the eam you need to make sure that you don't clip off the top of the head the frontal bone the oxital bone you put a marker up there and you're good to go so you can see here your MS p and your IPL need to be nice and straight and here is supine so this is a prone um Rec Covenant position so same thing you're going to go in 2 in superior to the eam you want your IPL U perpendicular and your MSP parallel and you want it straight so you can see here nice and straight both lines and what we're looking for for a good lateral skulls we want the orbital plates here so the super orbital margin we want these superimposed these plates they need to be superimposed here we have your e and you have an e so this is a right lateral so as you can see this left eam is bigger it's magnified because it's further away so you can see here we have some tilt so what this means is the patient's head is going towards the board so your MSP is not straight so this is pretty much just tilt now rotation on the eams one would be in front of the other so if there's tilt one's higher than the other so you can figure out which way it's going based on the size of the E so here if we had rotation it would be front or back and top to bottom is tilt so we have the catura here external acoustic meatus we have the temperal mandibular joint right here and we have the Petrus portion of the temporal bone we can also look at the Rami to see if there's any tilter rotation so when we start working with the facial bones we look at the uh Ramis we look at the orbital plates and we look at the E and to see if there's any tilter rotation because you're going to have to be able to identify which one you have sorry this that hold on yeah right lateral school I was like what so this is a left lateral School threw me off sorry guys so this one here the orbital plates are off by a little bit you can see just a just a little bit off here's your C Tura with your dorsum Cella and you can see here so this is your right eam this is your left eam why this one's bigger it's magnified right by way so we've got a little bit it's starting to kind of shift it's not straight up and down it's a little bit off so we've got a we've got tilt and we've got a little bit of rotation you can see these plates aren't lining up exact also and if we look at the Mand it's off by a little bit back there in addition all right so here we are with your dorsal decubitus lateral skull and um you're going to want to use a grid with these um they turn out much nicer now we usually do this position when the patient is on a Blackboard and Blackboard is on a backboard and in a collar um we do that to see if there's a skull fracture so we'll just shoot this real quick and if we have air fluid levels within uh the skull um we know that we have a problem there's some kind of bleeding in here um if there's air we're really concerned because then there's air getting in through the base of the skull which is not good so here you can see we have a fluid level some kind of fusion um it's most likely blood so we've got a fracture somewhere that we need to be very careful with this patient they usually go straight to CT from this point all right so here's another way to get it you can see we've had to bolster this patient up on a sponge so we have a sponge here so we have our IPL um perpendicular and we have our MSP parallel nice and straight and we're going 2 in above the E all right so PA and Pa axial so this is your Codwell so we have a PA with 0 degrees and we have PA axial which we're going to put an angle on so you have the patient um seated ere or prone your MSP is centered to midline your forehead and nose resting on the table or upright Bucky so forehead and nose touching you want your oml perpendicular to the IR plane the MSP perpendicular to the IR and the IR centered to the Nason so you're going to Center this at the Nason so for the PA projection it's um your CR is coming in perpendicular and you're just going to exit at the Nason so you have no angle you're just coming in straight and you're going to exit at the Nason so put your crosshairs right at your Nason and have everything line up coming in nice and straight so for the PA axial when we say axial we're talking about putting an angle on there so when you hear the word axial it's an angle okay so if we just say PA or AP projection no angle if we say PA axial it's an angle so that's what we call a Codwell so we're going to angle 15° coddle so we're going to go cod add so we're going to take 15° head towards the feet exiting the Nason you're still on a 10 x 12 and you're still going to cumate to the patient's Anatomy so here this is just a PA with zero angle don't look at how their bu is not lined up don't do that that they're off so oh my goodness so here we're going to exit the Nason you ar your oml perpendicular and you're going to exit the Nason okay now you can see how in the real world we would actually shift up a bit we do not want to expose all the way through his apases um and get his whole c-spine um so when we talk about positioning for the skull and the facial bone what we're going to teach you is what you need to know for your National exam that is going to change when you're in clinic if you shot this in clinic I would cringe um I would want you to shift up and colate in nice and tight just to the skull not the sepine I don't want to see the Apes all right so when we're looking here we have um pattle bone on both sides we have your frontal bone you have your dorsam Cella with your Superior orbital margin here with your paches ridges coming through here so the paches ridges fill the entire orbit so we have the ethmoid sinuses the crystal Galley sticking up right there all right so that's what we're looking for with 0 degrees here we have the PA axial which is a 15 Dee codal so you have your oml perpendicular so you can see your oml is perpendicular and you're going to be exiting the Nason and you're coming in at 15° codat so here you can see this is a zero angle this is 15° you have your own om L and you're coming in exiting the Nason right there you want your MSP nice and straight MSP and IPL so on the table this is what it would look like here's your 0 degree angle right here and here's your 15° here's your oml and you're exiting the Nason MSP straight all right so this is your 15 degree and you're going to have your peaches ridges in the lower 1/3 so you have your fontal sinus your Crystal Galley your Superior orbital margin you've got your ethmoid sinuses here Superior orbit Fisher oh right there and you have your peaches ridges in the bottom third and um here's your infer orbital margin right down here so um different than a zero zero angle takes up The petus Ridges will fill your orbits whereas on the 15° Cod ad on the u pa axial Codwell you have them in the lower 1/3 so if you have them filling the orbits you need to be able to tell the difference and say that's a zero angle so be sure you can tell the difference so this is just a different way of getting it um roll them up on a sponge so that you can get your MSP nice and straight his looks still obliqued a little bit his IPL looks a little off um in a trauma situation um you just get the best that you can get okay all right so we were just talking about PA axial projections now we're going to go into the um AP and AP axial projection so the difference is you're going from PA now to AP so on your AP axial what we're going to be doing is angling the opposite direction right so they're similar um but the AP you're going to have magnification of your orbits right so for the um PA patient and part position they're going to be supine or upright um if you can do it upright you should be doing PA right so this is typically supine MSP Center to midline and your MSP and oml perpendicular to the IR you're um for the CR is perpendicular so 0 degrees or 15 degrees sead for AP axial you're still at the Nason so you enter at the Nason and it's a 10 x 12 and you're going to callate to the anatomy so you can see here you have your oml here and you're coming in at your Nason so you just consider the light going straight through okay so that's the easiest way so you want your IPL straight and your MSP straight so for your um axial so your AP axial projection for your Codwell you're going to go 15° so here is your um oml so you are going to angle 15° from the oml so you're going to take this and you're going to do 15 Dees from it and entering at the Nason See's a little high so come down just a hair I'm being picky all right all right so this is what it looks like you have magnified orbits and this is the uh 0 degree angle so this is just straight and you can see that The petus Ridges here fill up the orbits all right so the towns method so AP axial towns the patient is supine or seated erect the MSP is centered to midline MSP is perpendicular to your IR and your oml or I ml is perpendicular and we're going to talk about the angle differences between the two and I pointed that out earlier but we're going to show you where this comes into effect so you want the IR so your image receptor um the top Border level with the skull vertex so you want the top of your IR at the top of the skull so your IR is centered at or near the frame and Magnum and you're going to enter two or well you're going to have the light come through or near your frame of Magnum which is about 2 and half Ines above the gabella and passes through the level of the E so you can do it either way I know Jeremy and I both um accept both answers so the CR is directed through the FR and Magnum so if you're at your oml so if you have your oml lined up it's a 30° CAD angle if you're at your I oml it's a 37° coddle angle so the difference between the oml and the oml is 7° remember it's 8 degrees going up to the U gabella so you somewhere around there we're we're not exact but for your National exam they're going to be requiring that you know the difference between the two I think they put seven to eight but you know there you go okay so here's your oml So the patient's upright you can see that the top of the film or the film how old am I the IR uh the vertex you can see it right there so you're right at the top you're about 2 and 1/2 in above the Cabella passing through the e to the um frame of Magnum so with your oml you're going to go 30° CAD so 2 and a half inches up 30° Cod ad passing through the eam so they're a little high come down just a hair and You' pass through here right through the um base of the skull there so looking here we have your o m l and we're going 30° through the e 2 and2 in above through the E through the frame of Magnum so if we're going to go I ml you're going to go 37° coming down through okay so same idea same positioning um just different angles based on what line you are centering from so here this is supine you've got your oml and we're going 30 30° so here's straight 30° from the oml and that's a big 2 and half inches you think I think they measurements off I go about right there bringing it through so that would bring it right through uh your e through your frame of Magnum so I think they're a little high in this diagram just so you know all right so same idea you have your oml and yourl and we're going 30° versus 37° and this is what we look like when we're done so this is a 30° and you can see here we've got the prial bones oxital bone your frame and Magnum here so if I point to this and I have LTT of lines going around that's your frame and Magnum if I'm pointing to this inner structure right here this is your dorsum Cella and then you have your posterior clinoids out here all right and this is your petus ridges on the side so here we have your dorsum Cella your posterior clinoid processes and peaches ridges frame and Magnum okay so this is a trauma case and we're going to study trauma later on and um this is looking you can see here pretty close to yourl it's more a canthon um so you would have to calculate for your canthon on your angle okay so um a lot of times I'll just take the the central Ray and I will line it up so it's com coming in straight and then angle based off of that I'd calculate the angle based off of that how far off I think it is okay and we'll talk about that when we get to trauma more so okay so this is an angulation uh for trauma to see the frame and Magnum uh really well we will sometimes angle um between 40 and like 60° depending on what we want to see so here if you're your oml if we go 45° um you're going to see here we have a lot better view of the occipital bone and of the frame and Magnum so you can see the posterior Arch is C1 and we've got a mandibular coni petus Ridge your perfect view of your frame and Magnum it's great shot and then if we go 55 degrees excuse me um really good for the frame and Magnum so it's even better so it depends on what they want to see and through here um sometimes uh we can get the uh odontoid through here so here's the dens right here and then here's your posterior arches C1 so really good shot right there of your frame of Magnum okay so here is an AP axial skull with the patient lateral decubitus with the IR and grid vertical so look how old this system is wowe anyway so this is the same idea it's just a different way to capture it um if the patient's not able to stand or they're too kyotic to actually or um to do it with them supine this is another option so I'm just showing you other options everything else stays the same so your IPL MSP your uh two 2 and a half inches above all of that stays the same okay so here's your PA axial which we call the hos method patient position so they're seated or um upright MSP is Center to midline shoulders in the same horizontal plane and your forehead and nose are on the table and your MSP is perpendicular and your oml is perpendicular so your CR is directed sead at 25° to the oml so it enters at a point 1 and 12 in below the external o occipital protuberance and exits 1 and half in superior to the Nason all right so what does this look like here we go this is hos so patient is prone or it's a PA you have your oml and you're going to go 25° from the oml sead so here we go you have your uh oml and you're going 25° and you're going to go 1 and 12 in below the occipital protuberance exiting the patient 1 and a half in above the Nason so 1 and 12 inches below the occipital protuberance external occipital protuberance and 1 and half inches is superior to the Nason so you can see here 1 and/ 12 in below 1 and2 in above 1 and/ 12 in below the external occipital protuberance 1 and a half inches above the Nason one and a half one and a half all right you can see here this is upright so you have 25° you're going sead so you have the 1 and a half to your external occipital pance to you have your oml and you're 1 and2 in Above So if you're using using your info orbital you have to calculate out 7° all right so here you have your occipital bone you can see really well your pdal bones here and we've got your um we can see your saddle here so we've got the posterior Ridge and this is your frame and Magnum within your frame and Magnum we have the posterior clinoids right here you can see them perfectly we have the dorsum Cella which is the posterior portion right there and this is your sphenoid sinus right there so it's shows us if there's any fluid or anything in there all right so you can do cone down views um to see the catura using the hos method um you have to be pretty good so you can see here we can see um within there really well so here's your frame and Magnum you've got your petus Ridge with your mastoid air cells your posterior clinoid processes on either side with your dorsam Cella here so if I asked you to label this I had dots around here frame of Magnum dorsum Cella cloid processes posterior cloid processes petus ridges mastoid air cells and then your spinoid sinus is right there all right this is your last projection this is your smv or the Schuler method so the patient is seated or upright so be careful if the patient is um seated or upright you need to be really careful with the patient um if they're laying down if they're supine you need to make sure that the Torso is elevated so your MSP is Center to midline your I ml is parallel with the IR and I'm going to show you what I mean by that your MSP is perpendicular to the IR so your CR um it goes through the Cela perpendicular to the oml so I'll show you how that works enters the MSP of the throat between the angles of the mandible passes through a point 3/4 of an inch anterior to the level of the eam and it's you Center the IR and the CR so you column 8 to a 10 x 12 this is what it looks like so you have your I ml parallel to your image receptor so they're in the same plane so you want this cranked all the way back so this patient has a parallel I ml you're going to enter between the goons so here you can see here we have the I ML and your central Ray coming through the angles of the mandible com right through so they also say um passes through a 3/4 of an inch anterior to the E so you can see H it's not quite 3/4 that'd be about right there right so they're a little posterior and so here's your eam right there so that's about right and here's the angle of your mandible so that works laying them down so you can see how you have to bolster the shoulders up to get the head to drop back now you when you get to the sinuses and the facial bones you're you're not supposed to angle your tube when you're doing this on a lot of views this is the only view you are allowed to angle um the tube so if you're doing a sinus you can angle on the smv for any view you need for the smv just keep that kind of stored in the back of your brain so here um you can see that we're kind of we're off by quiet a bit so we're not we're not angled quite right so you're going to angle your tube to compensate so that your infraorbital meatal line and your uh tube are coming in perpendicular to each other so this line right here needs to perpendicular your tube angle okay so that you get a true uh smv view so here your infraorbital meatal line and your CR you're going to angle so they're coming in at 90s you can see here this is your smv and this is what you're looking for if you're doing it for the skull you probably should not clip off the back so it should look more like this so if you're doing it for the skull don't clip it if you're doing it for facial bones you're going to clip it right here you're going to cut it right across so here is your maxillary sinus and we have the ethmoid air cells here this is your mandible so this is uh your uh goons here so this is your angle of your mandible or cond and we have your what do I want you to know here sphenoid sinus so ethmoid and sphenoid this is your dens or dto uh process pars petosa or your petus ridges mastoid air cells and this is your occipital bone with your frame and Magnum right in here okay so um you can actually see your zygomatic arches here so you're going to do this view for those in addition all right so that is all of your positioning for the skull you're going to want to go through all this a few times Jeremy's going to work with you in addition and you're going to practice uh Imaging and seeing uh the Tilt and rotation you'll also have to do your image analysis book um so be sure to study up what you're supposed to see in each View and um how it's supposed to be displayed so memorize your lines your um your gabella mial orbital meatal infraorbital meatal Canam meatal mental meatal uh you need to know your MSP and your IPL and we're going to use that lingo moving forward all right I'll post your quiz soon