 Hello everyone this is Dr. Sanjeev Mani from Indian Radiologist. Today I will be speaking on liver segments as we see them on ultrasound as well as on common hepatic lesions that we come across in our day-to-day practice but first let's go straight to the liver segments. We know them very easily on CT scan but it's very easily seen on ultrasound as well and the way of justifying these segments on ultrasound is the same system as well. It is a Q-node classification of hepatic segments where the liver has been divided into eight segments based on the vascularity as well as the biliary radicals that is each segment has its own inflow of blood, outflow of blood as well as a biliary radical. So it's a very simple way to differentiate it and know these segments on ultrasound but first let us understand how they are labeled. So it's a pretty simple you start from the left lobe and we go two four eight seven that is two and four are the left lobe of liver. Eight and seven are the right lobe of liver. Now these divisions are made by the hepatic veins that is the right hepatic vein the middle hepatic vein as well as the left hepatic vein and I'm going to show you how on a demo. As we go below this level the level of the total vein as it crosses through the liver becomes the benchmark for the segments below these four segments. So those four segments that are below these segments will be six that lies below seven, will be five that lies below eight. Four is actually divided into four A and four B and there'll be three that lies below two. So simple way to remember is multiples of two you go two four eight from left to right and then go downwards. So again from eight there will be seven will be six five four and three. So let's find out how this works out. So again if you come to this diagram once more we have two four eight seven we're going downwards right so below seven will be six then five four and three. We have the hepatic veins that divide two four eight and seven and the total vein level which divides three four five and six. One of course happens to be the corded rope. So let's start scanning. Well here at the top of the liver you can see the IVC over here this is the right rope and we can see the right middle as well as the left hepatic vein. So you can see the right hepatic vein here middle hepatic vein here left hepatic vein here. So if we pause right here I have the right hepatic vein and the middle hepatic vein so we've got to know that the segments are between over here here as well as here. Let's go back to it. So if we pause here as well you can see left hepatic vein middle hepatic vein and right hepatic vein. So this segment over here to the left of the left hepatic vein becomes segment two this becomes segment four so four A because it is a superior level this segment between the middle hepatic vein and the right hepatic vein will become segment eight and the one to the right of the right hepatic vein will become segment seven. So we have two four A eight and seven. Okay once again clearly seen dome of diaphragm right branch middle branch this is segment seven and segment eight. Now let's move down and what we see here is the portal vein. So this level marks the difference between the superior and the inferior segments. So if you remember a segment below seven or six one below A plus five one below four A is four B and one below two is three. It is at this level onwards and inferiorly that we will mark the lesions in those particular segments as six five four B or three. So as we go on we see the main branch of the portal vein here and we move inferiorly towards the kidney. So this is the inferior aspect of the liver we know so when we see the kidney and we see corresponding liver tissue there that becomes segment six. So let's try to understand this by seeing some common cases that we come across in our day-to-day practice. This is our first one again right loop of liver we know that this is the right branch this is the middle branch of the hepatic vein. So anything to the right of the right branch of the hepatic vein will be in segment seven. What we're seeing here is a small little grand pneumatic lesion or a calcified lesion in segment seven benign condition leave another lesion. Next case again we see a cystic error you know it's a cyst it's clear thin walled dark one ultrasound or hypoechoic with posterior acoustic shadowing you're seeing the kidney right here so this is at a level below the portal vein where you see kidney here you see the right lobe of liver and hence this becomes a lesion in segment six. So like I said characteristics of hepatic cysts these are very clear well-defined thin walled posterior acoustic enhancement that you see which is a classic ultrasound artifact that helps us differentiate these lesions and know that they assist and of course the location adjacent to the kidney and in the lower part of the right lobe of liver actually it is below segment seven so this becomes segment six. We move to our next case now and we have a young male about 40 years old with the fever and right upper corded pain you see again a lesion which is fairly well defined however it has got a lot of internal echoes within it and as you can see it's in the upper half of the liver this happens to be the dome of diaphragm and this happens to be the right lobe of liver so we got to find out in which segment this is okay that's the kidney so this would be segment six so it's higher up once again we make our probe transverse look at the lesion look at the kidney and you know it is higher up and we can check and look out for these hepatic veins right here and what we can see once again I'm looking down to see that there's nothing in segment six but as I go up along the level of the hepatic veins you see this lesion right here and as we trace the hepatic veins you know this is right and middle we try to assess where exactly this lesion is put on the Doppler and if I pause it right here that's our dome of diaphragm that's the IVC that's right branch that's the middle branch and you see the lesion to the right of the right branch and hence this lesion is a segment seven lesion once again you can see this three hepatic veins in fact the right branch is getting deviated that's left middle and right so this lesion is a segment seven liver abscess usually liver abscesses end up in the right lobe of liver because of sequential blood flow in the portal vein because the amoebic infection usually lies in the secan and ascending colon and that flow usually ends up going towards the right branch of portal vein and hence the area of the right lobe of liver usually segment seven and eight happens to be a common spot for amoebic lesions move to our next case now once again this is a tricky case because this patient came with a calcified lesion in the liver however the pet CT showed high metabolic activity which was very unusual so we had a look on ultrasound and you can see a calcified lesion right there we will check where the lesion is this lesion is in segment 4b as it is to the left of the portal vein you see a calcified lesion but just next to that lesion you are seeing another hypoechoic area right there so you see the calcified lesion you see a hypoechoic lesion so you know it's a new lesion this patient was C.A. colon the calcified lesion was an old lesion in the liver and the patient unfortunately had developed a new hypoechoic area which came up on the pet CT but when we did the ultrasound and we go back to the pet CT you can see that that's the calcified lesion but there is another abnormality right there in the left loop once again another case liver right lobe IVC right branch small lesion right there under the diaphragm to the right of the right hepatic vein so hence segment 7 fungal lesion again thick walls edematis internal echoes patient had fever and epigastric vein so you know this is an abscess all right it's an abscess in the liver now we want to know which segment this is okay so once again we're looking at left lobe actually because you can see the heart right there and that's the stomach so this happens to be in the left lobe almost hitting the capsule and again we will look at the section where we see the hepatic veins we're seeing the hepatic veins right there you can see the middle hepatic way in there and you can see the left so this lesion lies between the middle hepatic vein as well as the left hepatic way as well as well as to the left of the left hepatic vein as well so this lesion lies in segment 2 and 4 a so when we put on the color because we're getting some artifacts from the heart but you can see that left branch left hepatic way in there and right hepatic way in right here so this happened to be a lesion in segment 4a and 2 of the liver and next case once more IVC boom of diaphragm right branch middle branch left branch segment 2 segment 4a segment 8 segment 7 and let's see where this lesion is going down at the level of the portal vein so what was below segment 7 will be segment 6 what was below segment 8 will be segment 5 below 4a is 4b and below 2 would be 3 and we see this lesion alright again what is it thin wall cystic acoustic shadowing as a hepatic cyst we don't see it at the level of the hepatic veins in fact we say a level at or below the portal vein so it is in the inferior segments so now you don't know whether it's 6 5 4b or 3 so we don't see it here but we see it below we see it to the left of the portal vein so this happens to be below segment 4a and hence this happens to be segment 4b what is it it's a simple cyst in segment 4b of the left loop of liver our next case again IVC right middle left 2 4a 8 7 let's move on so we have now moved below those hepatic veins we move to the level of the portal vein so again when we are the level of the portal vein you got to look what was about this what was about this it was segment 4a about this so this will be segment 4b what do we see slightly regular but pretty echogenic and pretty homogeneously echogenic lesion seen in the liver commonest condition is a hemangoma common and leave alone lesions this again was an interesting case we see lesions in the right loop of liver so initial look was hemangoma but when we look very closely a few of them like about 3 4 over there in number however some of them had a slightly hypercaria inside you can get them in atypical hemangomas you can get them in large hemangomas but ideally we would want further investigation probably a triple phase CT to confirm this finding now move to another case and here you can see an irregular outline of the liver and this is a patient which is non-alcoholic clearly defined irregular left loop but as you move to the right loop you see a large echogenic lesion not like an hemangoma of course although it's fairly homogenous but you have a slight central echopore area and we're seeing this in the right loop and in a patient with cirrhosis the first diagnosis an only diagnosis that comes to mind is a hepatoma always always check for portal vein all right you have you may be doing a simple ultrasound and you say why should I put on color not a bad idea to put on color to see the vascularity of the lesion in the liver the hepatoma as well as to see portal vein for tumor thrombosis so this should always be done even if the request is not for a Doppler study you come to another case what do we see again this patient of cirrhosis seeing a very dirty picture all right but if you look carefully what we do see is a mass out here you can see a mass lesion right there so this also turned out to be a hepatoma but look closely at the portal vein you see it echogenic it's filled with material inside and this is tumor thrombosis it's extension of the tumor into the portal vein causing portal vein thrombosis this is a very common or should I say not so uncommon condition that we see in hepatomas especially those that come up quite adjacent to the point and of course we put on color you can see a slightly tram track appearance right there but you do not see the clean flow that we associate normally with the portal vein so this condition is a mass lesion hepatoma with tumor thrombosis formation within the portal vein once again the lesion lies adjacent to the portal vein at the level of the portal vein so it can't be the upper segments it's the lower segments it's turned out to be a lesion in segment 5 as well as 6 another case over here again once the lesion so what you see this patient was asymptomatic actually routine checkup medical checkup again hepatic veins right and middle you see the lesion adjacent to the right hepatic vein just below the diaphragm look like an old infected lesion or old saw some slight limb calcification also in it so again middle hepatic right hepatic diaphragm lesion this happens to be segment 7 what was it it turned out to be an old hydrated as the patient had history of having hydrated infection in the past with a clear unilocular cyst about 15-20 years ago the patient had preserved his records and you can see hydrates in various forms you can see them it's unilocular sometimes sometimes you can see tortoises you can see ruptured hydrated sometimes going into the lung you can also see a water lily sign because of collapse of the endocyst the membrane however nowadays we see hydrates is not so commonly like we used to maybe a decade ago on no case see every and as soon as you put your probe on the liver you see these multiple eco-poor lesions high-poor as well as hyper and instantly you know this is liver metastasis you see it started both lobes for the left side as well as the right side and this is quite a simple diagnosis case of liver metastasis involving both lobes of liver so with that we come to the end of this tutorial I hope you enjoyed it and if you did like it please do comment like or share and once more there's a shout out for Sonobas the conference that's on-site in person and whatever you call it we're gonna have a great time it's on Jan 8th and 9th details are on our website IndianRadiologist.com have fun and take care this Sunday bye bye