hi learners it's em from sono nerds and this video is on unit 11 modes unit 11 modes way back in unit 1 we talked about how a graph looks we have the y axis as the vertical line the x-axis as the horizontal line and the z-axis representing more of a depth line which creates the 3d world now the concept of the graph is important as we think about the different ultrasound display modes an ultrasound display mode is the way that the machine interprets and displays ultrasound information on the screen each mode has its own purpose there are three display modes that we are going to cover amplitude mode which is known as a mode brightness mode or b mode and motion mode or m mode while you are studying these different types of modes make sure you understand what they look like and what variable is displayed on each access section 11.1 a mode the a and a mode stands for amplitude in a mode the machine displays a graph that has a spiked appearance each moment on that graph represents the amplitude or the strength of the returning echo really tall spikes are going to be really strong reflectors where shorter spikes are weak reflectors and no spike is no reflector to create the graph a dot basically travels along the screen mapping the reflections that are received from one scan line as the scan line receives a strong echo the dot's going to jump upward weaker echoes are going to have less of a jump and if there's no echoes it just kind of flatlines so if we could superimpose an image over what an a-mode display looks like we would see that the strong reflectors are bright white those weaker reflectors are going to be different shades of gray and then the non-reflectors are black or anechoic and in this image we've done just that notice how we have really strong reflectors here and they match up with this really bright white strong reflector in the image notice how it's relatively flat through here that's matching up with this dark anechoic area these weaker reflectors in between match up with the weaker grays or less strong reflectors in between as that dot comes across the graph it's going to get to a strong reflector jump up the next reflector is a little weaker so it comes down a little bit stronger really really weak weak weak weak very anechoic another really strong one again and so we're going to see this dot jump around kind of mapping out these strong reflectors with these different spikes now what we're seeing in this image is a picture of an eye and that's because ophthalmology practices or eye doctors are typically the ones that are going to be using a mode actually works out really well for them to be able to see the parts of the eye and any abnormalities within the eye and not that you need to know any of this but the transducer is placed against the eyelid here and then i believe we have the lens of the eye this is the kind of viscous fluid within the eyeball itself and then this is the retina and back and then i believe we get into the nerve behind the eye so the really big thing that you're looking for with amplitude mode is that those strong reflectors are going to be tall spikes weak reflectors are short spikes no reflectors are flat or the anechoic areas on our images another way to look at a mode is to think about how it resembles a city skyline the x-axis of the amo display shows us the time of flight of the pulse or the depth so this is very superficial over here and this is getting deeper as the dot travels down the scan line into the depth of the image so superficial structure is on this side and we have deep structures on this side so the x-axis the horizontal axis on this image represents depth the y-axis is going to show us the amplitude or the strength of the reflectors so remember the taller the reflector the stronger the echo is returning so very strong echoes midline echoes and weaker echoes section 11.2 b mode now the b in b mode stands for brightness so b mode is our gray scale mode and that is the one that we typically use to make our diagnostic images the sector which is the image window that creates our picture is made up of many lines we've referred to these before as the scan lines they are created by one pulse going down to the maximum depth returning to the transducer and each scan line is made of a pulse on the display then those scan lines are translated into tiny little dots which are called pixels in original b mode the pixel could either be on which would represent a white pixel or it could be off which was a black pixel i could actually have an image of that here this was one of the original b scan images again pixels could either be on or they could be off but current systems look much more like this where we get a variety of blacks whites and grays in between describing b mode in the terms of graph is a little bit trickier though so far we've learned that the y-axis is the vertical line and the x-axis is the horizontal line so it might be really easy to take a look at an ultrasound image and think well this is y-axis this is x-axis the problem is though is that the vertical and horizontal line are referring to a point of origin and in our case we consider the transducer our point of origin so if the transducer is up on this top part of the image our horizontal is actually going to be this direction so the x-axis is the line coming from the transducer it is the line following these scan lines so if that is our x-axis what we are representing on the x-axis then is the depth of the reflector so reflections that are near the transducer appear at the top of our images reflections that are far away from the transducer appear at the bottom of our image so this is the x-axis in our image now what gets even trickier is that we have a z-axis in our b-mode imaging i mentioned earlier that we have something called an oscilloscope an oscilloscope is a tool that we use to graph a wave so we can get the amplitude and the sinusoidal waveform on a electronic device called an oscilloscope so when that oscilloscope maps or graphs amplitude it does so on the z axis so what we end up getting in return then is brightness being displayed on that z axis so if you could almost pretend that each of these pixels is that spike coming out kind of like in amplitude mode if we had like really bright spikes coming out toward us in these pixels and no spikes coming out towards us in these pixels we would kind of start to understand how amplitude could be graphed on the z-axis so i know this one isn't super intuitive so this is probably one of those memorized ones x is depth z is brightness in b mode section 11.3 m mode now the m in m mode stands for motion m-mode is going to be used to graph the motion of anatomy over time and this is going to be extremely helpful for many cardiac applications like watching the wall motion and measuring ventricle size just to name a couple obgyn sonographers are going to use it to evaluate the fetal heart and it can be used in emergency medicine to observe lung motion m mode uses one scan line as well along that one scan line is going to map the motion that is occurring in that line so as the sound beam enters and returns from the body the machine displays different grays that correspond with the b mode image and then it's going to do this very rapidly so motion can be detected within the one scan line the sample rate or how quickly the machine can sample down that one scan line is equal to the prf of the system remember depending on what your depth is is your prp your prp then determines your prf so each pixel in the scan line of the beam mode is recorded over time in the m mode graph so if we see a horizontal line that is very squiggly that anatomy is moving if we see a line that's horizontal that's going to show no motion if an echo is near the top of the graph that means it's more shallow and if it's towards the bottom of the graph it's a deeper structure oftentimes we're going to see a b mode image above the m mode image so we can correlate the structures that we're seeing in our m mode graph and correctly place the m mode scan line so i know that was a lot let's go over this image and kind of recap some of that so here's our b mode image up on top here and you'll see that there's one scan line represented through the image now this one scan line actually has these little dashes through this is not always the case but these are actually representing different depths so at five centimeters here that is going to correlate to the five centimeters on the m mode this dash represents 10 that is where we are here down to 15 at the bottom of the image represents down to 15 at the bottom of our m-mode graph now these numbers aren't always here these dashes aren't always here but it's the same idea regardless if you have a solid line or dashed line structures at the top of your graph are superficial structures in the bottom of your graph are deep in your image now as we are looking at what the m mode is displaying if we have horizontal lines going across that means this structure that is represented by these pixels within this line aren't moving so any straight horizontal lines mean a structure is not moving compare that then to this line which is very squiggly this is all kind of connected we get these spikes and squiggles in here well this line is going right through a valve so we are seeing the changes of the anatomy along this one scan line over time during the scanning acquisition process we can also see that this line is very echogenic it matches up with this line that is very echogenic so the gray scale that we get within our m mode graph matches up exactly with the b mode pixel brightness that we are seeing in our picture up on top so here's an example of m mode being used to evaluate lung motion again this isn't necessarily stuff that you need to know but i just want to explain some pictures to you when i can we've got a rib here a rib here this is the chest wall and skin and then underneath we can see actually not a whole lot of lung motion but this is the lung underneath so this is the scan line notice that this one is solid we've got five centimeters of depth this one also has five centimeters of depth we don't expect the skin of the chest wall really to move so we see that we're not seeing a whole lot of motion in here these are mostly horizontal maybe a little bit of breathing motion chest rising and falling and what they're looking for is to see this pleural space kind of sliding back and forth along the chest wall and it actually happens not to be doing it very well and we can see that reflected in our motion graph we are not seeing a whole lot of movement in these lines let's compare that then to a heart which is clearly moving again we have our one m mode scan line coming down this represents one scan line in the image this is that one scan line over time very quickly being mapped along with itself bright line on the bottom here represents this bright line in our b mode image and we are going right through the ventricle well so we can see the ventricle contracting and relaxing through the cardiac cycle and so from here we can measure how much wall movement there has been the size of the ventricle multiple things that apply to cardiac measurements same idea with ob gyn we can place our cursor right over the fetal heart and from that fetal heart then we can find a pattern within the m mode and we can find what the fetal heart rate is by measuring the distance between movements again we've got one line from the very tippy top of the picture all the way down to the bottom of the picture so these gray lines are not moving they represent the skin and fat layer on mom this black area represents the fluid that it's around baby this gets into the skin line of baby and then the heart motion and then the spine of baby here and then back into like uterus and more mom parts behind it so we are seeing one scan line being mapped over time any motion that occurs through that scan line so in our m mode graph then we are seeing depth along the y-axis of the m mode so superficial at top moving down into the depth towards the bottom we then see time being displayed along the x-axis this is old time getting to new time on this side and what we saw with those last clips that we had the time would come across fill up the whole graph get to the end and then it would start over again refilling the time representation through this graph and that is it that is all we really need to know about the three different types of modes so again be able to recognize what they look like by their images recognize what they are displaying along the axis so a mode was amplitude mode it shows us amplitude in the y-axis depth along the x-axis b mode is brightness mode it shows us depth along the x-axis and brightness or amplitude on the z-axis and then m mode is motion mode and that is going to show us depth along the y-axis and time along the x-axis make sure that you go through your very brief activity in your workbook and then as usual the workbook ends with some open-ended questions that you can use to quiz yourself