 So we'll start with the review of the normal anatomy of the organs that can be seen via trans-abdominal or transvaginal ultrasound and importantly the relationship of the organs to one another. So starting in this view in this schematic right here starting from anterior you have your pubic synthesis right here. Generally if you're going to do a general trans-abdominal ultrasound you're going to place your probe right around here on the pelvis. You're going to see hopefully not through the synthesis you're going to have to place it slightly above to image here through the bladder. The bladder you want to be nicely distended and that's for two reasons it's going to push any small bowel loops up and out of the way because ultrasound can't see well through bowel loops. It's also going to serve as a window because ultrasound waves travel faster through fluids so using that urine in a nicely distended bladder will help you to see the next organ right behind it which is the uterus here. Back here is going to be the vagina right here with the fournesses anterior posterior and cervix right here and then behind that we of course have the rectum posteriorly back here. Here's a labeled one where you can get a little bit more detail if that's helpful to you and again this is the bladder here. You have your vagina here your anterior your posterior fourness of the vagina the external osso the cervix is right here and then the internal osso can be variably difficult to see but should be somewhere right around here that's when the endometrium is going to start and you have your anterior portion of the endometrium and your posterior portion of the endometrium so that's going to cover the lower uterine segment of the uterus the body and then the fundus of the uterus right here and again posterior this is going to be the rectum again moving to this unlabeled view right here. It's important to remember too when you're going to do a transvaginal approach to imaging the cervix and uterus can be mobile so it can look different on your imaging depending on where it is at that particular time at that particular day when you're imaging it. This is an example the uterus can be anterior sort of flopped anteriorly onto the bladder here or it can be more posterior position as it is here and remember it's important because if you're doing transvaginal imaging your fixed plane of imaging is going to be via the vagina and you don't have a whole lot of wiggle room there to image this. So generally the patient is going to be placed supine on the table when you're doing a transidominal view. Again you're going to fill that bladder as much as possible to get rid of the bowel gas pushing that up and out of your image field of view and generally you're going to use the five curve as your general probe for transabominal imaging. The transvaginal probe however is a high frequency probe that means you're going to get high resolution imaging very beautiful pictures but because the frequency is high those ultrasound waves are not going to go very far before they get lost to forming the image therefore you have a limited distance of what you can view. However we don't image patients in an upright position generally we're going to see them as supine as we do here. So that transabominal view again you're going to put that probe directly onto their anterior pelvis right here and we use the bladder as a window to visualize the cervix and the uterus itself. That's going to create an image that looks like this so here is your five curve probe will be up here this is going to be your skin subcutaneous fat soft tissue some musculature then you have your anechoic bladder right here which is nicely distended creating a beautiful window so that you can see the uterus. We have vagina down here cervix is right around here lower uterine segment right around here from the body of the uterus and here the fundus is a little bit obscured due to bowel gas that didn't quite get pushed out of the way here. You also have some of the endometrial contents right here and a little bit of free fluid in the cul-de-sac. However transvaginally you have a limited field of view here again we talked about the high frequency waves you're going to get beautiful imaging high spatial resolution but it's not going to go very far the waves as they travel before they get lost to form that image. You're also limited by a fixed plane of imaging as we mentioned before. You can see in this example here the ultrasound waves may be sending waves in these different directions but it's not necessarily going to capture all of the uterus in a single plane right here due to that limited field of view. So it's always important to remember when you're measuring a structure particularly the uterus you may not get it in one field of view so your imaging may not be perfectly accurate when you're looking for a length of different structures. Another thing to remember when you're doing transvaginal imaging is now you want the bladder to be decompressed so that patient is going to need to empty their bladder and that's for two reasons. Number one is patient comfort it's really uncomfortable to have a transvaginal probe there and to have a full bladder. Number two is if this bladder is overly distended you can imagine it's going to push that top of the uterus back and if it gets too far in a sort of upright position it may actually be too far to get good images of it because remember high frequency probe you need short distance to get those beautiful images so two things there to keep in mind. So with that all being said are we ready to look at some ultrasounds? Okay so this is an image from a sagittal uterus this is labeled right to left so I took this from a cinecliffe but just to give you an idea of what we're looking at this is your transvaginal probe right here it's much more curved than the other one was a sharper curve there. You can also see in the corner right here that it's a nine that's a much higher frequency than your general five curve that you're going to be using. So this is going to be in the fornix of the vagina you don't really see the vagina here again because the probe is within it so what you're seeing here is what is up against it so in this particular image we don't really see the cervix that well again there might be a bend to the uterus which doesn't allow you to see it perfectly in one single plane but here is the anterior part of the uterus so lower uterine segment body fundus coming around here and then posteriorly uterine body lower uterine segment and then we get down into the cervix down here back here is going to be rectum you might also have some mesenteric fat you might have some valutes nearby depending on what's there on that given day more centrally you're going to have the endometrial lining which will vary depending on the stage of menstrual cycle and then oftentimes you can see the arcuit arteries of the uterus kind of going all the way around right here especially if you put on color Doppler here it's important to remember that the size of the uterus varies depending on the age of the patient when their pediatric that's going to be small and it's going to grow to reproductive age about eight to nine centimeters in length it may be larger if the woman is multi paris rather than null paris woman so more kids you may have a larger uterus just in general it then starts to decrease in size in the postmenopausal status and then it depends on how far postmenopausal you are it can get down to three and a half centimeters in length if you're very remote from your menopause onset and then of course endometrium it's going to vary depending on the stage of the cycle in the reproductively aged woman and we'll go over some of those in a little bit