[Music] uh hello I'm Dr oana baltarowich uh from the Jefferson ultrasound research and Education Institute at Thomas Jefferson University in Philadelphia and I'll be speaking about uh liver sonography we're going to discuss um the normal liver uh we'll talk about Doppler of the hepatic vessels um we'll talk a little bit about diffuse uh liver disease patterns then move into Portal hypertension and focal liver masses now the normal liver uh uh when we look at it sonographically we pay attention to the size of the liver the shape of the liver the echogenicity and the echotexture the echogenicity and echotexture two different uh things that we talk about echogenicity has to do with the level of brightness of the liver parena and we use portal vein walls uh to compare that and texture has more to do with the homogeneity of the liver uh the liver is very susceptible to technique uh we have to make sure that we have a nice smooth uh TGC curve we want to make sure that um the penetration goes all the way back to the diaphragm here is this curval linear bright structure uh we would like to have the vessel wall vessel lumens clear of uh extraneous Echoes and when we scan the liver we want to make sure that we clear all of the margins of the liver in this case here we have very good technique coming through this side of the image we have nice echogenicity clear vessels we get through to the diaphragm but here we seem to have some kind of uh division some kind of Dropout of sound so we would have to correct that uh either apply better um pressure uh on the abdominal wall uh and try to even out uh the echogenicity here of the liver uh one thing that's very important and this is important for all structures that we image in ultrasound we always want to be able to see at least 2 to 3 cm beyond the margin of any organ so that we can exclude uh possibility of any exoitic masses or any kind of adjacent masses that can affect the organ in this case here this is the liver the inferior edge of the liver would be here but because we were trying to clear 2 to 3 cm beyond the margin we noticed that there was a mass M hanging off the inferior edge of the liver we would have never seen it if we would have stopped our picture uh at the inferior margin of the liver and if you by the way this was a a hepatocellular carcinoma a hepatoma 5 cm hepatoma hanging off the margin of the liver and if you think that this is a an anecdotal or unusual case here's another case that we had Fairly recently hanging from the inferior margin of the liver was this large mass under another hepatocellular carcinoma hepatoma and that's the right kidney here now as you scan the abdomen you should always have in mind the different paranal organ echogenicities and have a a kind of a relative scale in your mind of the different echogenicities the Arenal medulla is the least echogenic of all the uh parts of upper abdominal organs the uh it is much less uh echogenic than the cortex uh of the kidney which in turn is less than or can be equal to echogenicity of the liver we used to think that equal to the liver was abnormal but now we know that especially in young people cortical echogenicity could be equal to liver echogenicity now we also know that the liver is less echogenic than the spleen but that's something difficult to to ascertain because usually the liver and the spleen are not on the same picture and you would really need them to be side by side to tell which one uh is more or less echogenic that can happen sometimes now this is a scan of the left upper quadrant uh and we're looking at the spleen here and we notice that the spleen has a sort of a double shade has a darker area and a more a brighter area almost like a a double shaded spleen however we also note that there are some little vessels in this part of the spleen not so much seen here and then we realize that this is liver this is the left lobe of the liver going all the way across to the left hugging the spleen and so that it looks like it's a part of the spleen and it isn't so this is liver which is indeed less echogenic than spleen and this is not to be mistaken for a subcapsular hematoma sometimes this is mistaken um uh in in the spleen so there's our proof now the liver is also less echogenic uh or equal in echogenicity uh to the pancreas pancreas are usually more echogenic uh but they can be equal especially in younger people so here is pancreas and here's the left lob of the liver and and they're fairly equal when we compare echogenicities we should be comparing at a similar depth uh of the of the beam oh and one more thing here that the pancreas itself is less echogenic than uh retrop paral fat which is hyper eoic uh and also less echogenic than the renal sinus Echo so renal sinus Echo and the retrop parital fat are hyper eoic and the most echogenic of all of these pranal organs when we look at the liver uh panoma itself uh we realize that there are little holes throughout the liver sometimes we see little cylindrical shapes and some of them have Bright Walls and some of them do not so then we have to figure out what we're looking at when we do ultrasound sonographically the vessels that are visible within the prum of the liver are the portal vein walls and the hepatic veins uh the hepatic arteries and the bile ducts typically are not visible within the prum of the liver unless they are abnormally dilated we can see them in the Porta hepatus which is just outside the liver but as far as being inside the liver we only see these two vessels if you think about the liver you realize that there are four tubular systems that go throughout the liver we have the portal Venus system uh the hepatic arterial system and the bile ducts these uh are intimately related at the pora hepatus they join together uh as partners in the uh portal sinus portal Triads and they stay together throughout their entire branching throughout the liver the fourth tubular system is the HP itic veins now the hepatic veins drain the liver superiorly towards the IVC inira uh and they stand alone they do not have uh anything associated with them uh and that becomes important to us we'll see in a minute so the portal Triads then are maintained throughout the liver uh and uh that's uh partially that is what is uh causing this reflectivity of the walls portal vein have bright echogenic walls and we use this for comparison of paranal echogenicity what happens is the main portal vein it enters the liver through the Porta hepatus and almost immediately splits into a right and left portal vein the largest portal veins divide horizontally approximately in the middle of the liver and they Supply loes and segments and they carry blood flow into the liver now the reason that portal veins have Bright Walls is number one because of the portal Triads which is the portal vein the little hepatic artery and the bile duct so all we're seeing here is the portal vein the little artery and duct are small so they just provide reflectivity we also have some reflectivity from gin's capsule from the little lymphatics and nerves and connective tissue isue around the portal Triad so that's why portal veins have Bright Walls hepatic veins do not and why is that well it's a matter of contrast um the uh hepatic veins have imperceptible margins they actually have walls but we just don't see them uh if we look at what they look like uh by configuration they're more vertically oriented uh they enlarge towards the inferior V AA and they actually have sort of an umbrella configuration where the spokes of the umbrella come together superiorly and the the rest of the spokes drop down throughout the liver now these um veins are found between loes and segments so we use them as anatomic dividers and they carry blood flow out of the liver they do not have any other adjacent little structures therefore we do not perceive uh their walls here's an umbrella just for your imagination you can see that the spokes of the umbrella come together at the top which is here so if we take a slice through the very Superior portions of the liver we can see longitudinal orientation of the hepatic veins now as the veins drop down and we take a transverse section lower these veins will be cut and look as like circles so here is the middle hepatic vein and here is the right hepatic vein showing us lower in the liver as a cross-sectional uh configuration cross-section which we would be doing through the spokes of the umbrella now having said that we always find exceptions to the rule now I just told you that portal veins have Bright Walls and now all of a sudden I'm showing you a picture of a portal vein that does not have Bright Walls some portal veins may not show echogenic walls because they become parallel with the beam uh parallel is the worst angle for bcan so we're losing resolution and we simply um lose resolution of this portal vein wall here on the other hand are hip hepatic veins now I just told you that hepatic veins do not have Bright Walls and all of a sudden I'm showing you a big hepatic vein with Bright Walls well it is true that some hepatic veins may show echogenic walls that's because they're large veins and they have thick walls so they do have reflectivity but also in this case this vein is completely perpendicular to the sound beam and that's the best angle for B scanning therefore we see the hepatic vein wall so two exceptions to the rule explained by um angles so we have some uh now a little bit of insight into the uh anatomic landmarks on transverse scans of the liver and let's look at these in high portions in the upper parts of the liver we see large hepatic veins coming together into the inferior ven AA in the mid portions of the liver we see the portal veins uh kind of horizontally uh situated uh the left being a little higher than the right uh but nonetheless with the Bright Walls that we know now that we're in the middle of the liver if we look at transverse lower sections of the liver we don't see any big veins uh we see an echogenic line here this would be where the the falor ligament comes in and the um umbilical Fisher the fisser for ligamentum terries and that will Mark the lower parts of the liver for us so we'll know if we're High mid or low in the liver now since I mentioned ligamentum terries let's talk about that ligamentum terries means round ligament we we have different round ligaments in our body but this is the round ligament in the liver which is the obliterated fetal remnant of the umbilical vein so the fetal umbilical vein once the fetus is born there's no need for that vein so the vein clamps down and becomes almost like a a thick fibrous uh kind of cord located within a fisser within the fisser for ligamentum terries so uh the Fisher is has a little fat in it that's what gives us bright reflectivity so somewhere in here is the collapsed um obliterated um Li ligamentum terries surrounded by echogenic fat this is a transverse section of the left lobe and that becomes a divider of the left lobe into medial and lateral segments on a transverse scan also notice that there's some shadowing behind this and the reason that it Shadows is because not because it's calcified and this should not be mistaken for a calcified Mass but it's because the ultrasound beam strikes this at 90° which is directly um striking this uh fibrous cord uh and that Shadows behind it as soon as you change the angle a little bit that shadowing will disappear if it was truly calcified there would be shadowing no matter what angle you come from the uh fetal uh umbilical vein came into the umbilical segment of the left portal we can see this when we uh cut the liver sagittally at this precise level we are now taking A sagittal image and we can see the brightness of the fat surrounding the ligamentum terries within this um umbilical fissure and notice that it goes directly into the umbilical segment of the left portal vein so that's where the fetal umbilical vein enters the portal system this vein May reach canaly in Portal hypertension uh and uh once again it is a divider of the left lob so while I mention fetal remnants I'll mention the ligamentum venosum ligamentum venosum is the obliterated fetal remnant of the ductus venosus the ductus venosus carried blood out of the liver in the fetal circulation blood entered the liver but there was no reason to stay in the liver so there's a ductus venosus that right away carries the blood out towards the inferior venic Cava and towards uh the fetal heart uh that uh ductus collapses once the fetus is born and it lies within the fissure for ligamentum venosum now here on A sagittal section that fissure appears to be a bright line which is located between the Cotate lobe and the left lobe of the liver behind the Cotate lobe is the inferior vena okay when we turn 90° and do a transverse section the fissure appears here again as a bright echogenic line uh somewhere in here we don't know where is the collaps ductus vosis probably closer here to the umbilical segment of the portal vein so it would have come out and on higher sections it will end enter the inferior vnea notice that that fissure is a broad plane it's a line on transverse it's a line on sagittal so it is not a linear kind of um uh fissure but it's rather fairly Broad and that is our divider for cadate lobe from left lobe of the liver this vein does not recanalize in adults you don't see this vein ever again except perhaps in the very small uh neonate that has umbilical vein catheters you might see it but once the child grows this vein uh is obliterated and does not recanalize in Portal hypertension I mentioned the cadate lobe when you think of cadate you think of something codal but yet that's not really what this means cadate in Latin means tail so the cadate lobe is like the stubby tail of a dog here's a little puppy here uh and it's actually one of the more cranial parts of the liver now we pay attention to the Cotate lobe because the Cotate lobe is functionally uh an autonomous segment and uh it is often been said that it is spared uh in liver disease it has its own blood supply it takes blood supply from the right and the left poral veins and you can prove this to yourself if you carefully scan if you have a good patient a thin patient and you look around the portal veins you can see small uh branches uh entering the cordate lobe and you can also see Venus drainage separate Venus drainage in directly into the inferior vena and supposedly that uh drainage here is what helps to protect the cordate from other diseases now another thing you should know about the Cotate is that it itself can look like a mass sometimes we call that a pseudo Mass here's a a section of the liver and it looks like there's a mass in the Cotate so I would caution you this is an artifact if you ever think you see a mass in the Cotate ask yourself first are you sure that that's not a pseudomass what happens with the pseudomass the ultrasound beam comes through uh the port portal structures and becomes attenuated so it partially drops out giving it the appearance of a hypo aoic Mass if you move off of this Porta and come in with the beam from different angles you will see that this is not truly a mass that's why it's a pseudo Mass also the Cotate lobe can become enlarged especially with uh therosis uh we can actually measure that this is described in the literature uh and the Cotate is enlarged when a certain ratio of the Cotate to the right lobe is enlarged so what we would do we would take a transverse section of the liver we would take the medial margin of the Cotate and the lateral margin as a lateral margin of the portal vein that we would measure as the width of the Cotate lobe and the rest of it is the width of the right lobe then we would take a r ratio of C over r or Cate over right lobe and if the ratio is over 0.65 that becomes an enlarged Cotate If the ratio is over 0.73 or so that's very um specific for sosis of the liver but you have to have the whole transverse scan on one picture it's easier to do on CT so now that we've talked about the hepatic uh and the portal veins uh this leads us into uh the basis of modern lowbar and segmental Anatomy uh the this is the basis of surgical uh procedures uh nowadays this is the reason why surgeons can go in and remove a Subs segment of the liver let's say a a metastasis in a Subs segment and not harm other parts of the liver uh this is possible because of now our understanding of this low bar and segmental Anatomy now we've already told you that hepatic veins drain peripherally so they are interlobar and Inter segmental therefore we use them as dividers portal veins feed the segments centrally so they are intralobar intras segmental and we use them to name the segments so here we'll start with the hepatic veins as dividers here's a transverse section high in the liver and we see the three hepatic veins veins coming together at the infer AA the middle hepatic vein divides the liver into right lobe and left lobe the left hepatic vein divides the left lobe into medial and lateral segments but this only occurs in the high parts cranial parts of the liver that's where the hepatic vein is the right hepatic vein divides the right lobe into anterior I and posterior sections okay so now we have right and left uh loes divided now the portal veins they feed the segments we name the segments and they Define the segments okay so here we have a portal vein with Bright Walls the main portal vein just came into the liver and immediately divided into a right portal vein which is rather short because it suddenly splits into the anterior segment and the posterior segment okay so this is the division of the right portal vein so here is the right anterior segment and here is the right posterior segment of the liver and notice here's our right hepatic vein and here's our middle hepatic vein this this plane of Separation middle hepatic vein in line with the inferi vinaa is our divider of the liver into right lobe and left lobe and the right lobe is further subdivided into anterior and posterior segments the left lobe the has uh its own divisions now here a after the vein split the main portal vein the left portal vein has a longer course it travels towards the left L and suddenly takes an Abrupt anterior turn this is the only part of the portal system that suddenly aims anteriorly okay that's the umbilical segment of the left portal vein and it sends off lateral branches and medial branches so this would be the medial segment of the left lobe and these are lateral segments of the left Lo this is used as a divider this is the only part of the portal Venus system that is used as a divider I told you hepatic veins are dividers but this is the only part of the portal system that's used as a divider in the midsection of the liver okay that's our um division of main uh uh middle hepatic vein dividing right and left loes so here we have our uh subdivisions on very well subdivisions in this case of the left lobe I I've already mentioned three I'd like to put them all together for you so we have dividers of the left lobe into medial and lateral segments high up on high sections it's the left hepatic vein that divides the left lobe into medial and lateral segments in the middle of the liver it's the umbilical segment of the left portal vein which divides the liver into medial and lateral segments and lower down where there are no big veins we have the echogenic FAL form ligament coming in and the umbilical fure dividing the liver into medial dividing the left lobe into medial and lateral segments so Superior mid and inferior Parts another uh point that I'd like to bring up here is about the division of the main portal vein precisely where the main portal vein comes in and splits right in that um line here we can use that as another anatomic divider of the liver if we look at the liver frontally or on Foss we'll see that that uh part of the portal vein divides the liver into Superior and inferior segments however so that's on coronal sections uh if we look transversely we slice up the liver and we find that division in the middle of the liver that will divide further into anterior and posterior segments so the same vein it's it's a tubular structure can divide things into Superior and inferior as well as anterior and posterior so it becomes useful all of that put together helps us subdivide the liver into subsegments which is useful very useful for the surgeon because if we can place a lesion in a specific segment the surgeon can then go after that lesion and remove it without harming other vascular uh segment supplied segments of the liver uh this is the basis of the quino system a French system that divides the liver into eight segments if we look at the liver from the front this would be the left anterior lateral segment behind it would be the left poster lateral segment way in the back is the Cate loob that's always segment one in in any system of classification because it kind of stands alone so we get it out of the way then we see the medial segments we have a superior and inferior uh medial Subs segment and when we get to the right lobe here we have uh anterior Superior in Blue uh and we have uh anterior inferior in purple for you to see the back I've rotated this liver slightly so here's anterior Superior anterior inferior in the back is posterior inferior and posterior Superior these segments are labeled five six 7even and eight it's kind of an unusual system it kind of twists around like a figure eight nonetheless each segment has a number now I don't think that you should learn all of these segments with numbers because you have to know what your surgeon uses your surgeon may not use this classification but if you divide and and explain that it's left posterolateral or right postero Superior they will know then which part of the liver the lesion is in so here's a little quiz name the sub segment with the cyst okay this is a transverse scan of the liver so where would you place this cyst what Subs segment this is transverse and here's A sagittal scan okay well I hope that you were able to uh see that this is the middle hepatic vein so this is in the right lobe and this is the right hepatic vein so that's in the anterior segment of the right lob and it's up high by the large hepatic veins so it's in the anterior Superior part of the right lobe which is segment 8 and that is confirmed here on the sagittal where this cyst is high up sagittally rather than in the lower parts of the liver so then you can tell um you can precisely locate this um lesion let's look a little bit at the uh portal veins uh for this we have to talk about the Doppler a little bit because nowadays we do more and more Doppler uh in a normal vein portal vein we have continuous forward flow the liver is always available for uh detoxification of substances uh anything that you eat anything uh any breakdown products from the spleen the gut Etc so it's constant forward flow with a low velocity if you did velocities usually they're 15 to 28 or 30 cm/ second the flow is in to the liver shown here on this color Doppler red means flow towards so we have flow towards the liver it's an undulating pattern which reflects respiratory variation and may reflect cardiac variation it's a slightly turbulent rough low Rumble kind of flow uh and uh that's because it's located between two capillary bits between the mesenteric Venus system and the hepatic Venus system what's abnormal well abnormal is when that flow becomes too pulsatile uh it may then start resembling hepatic vein pulsatility and that would mean that there's elevated right heart pressures and that there's transmission of uh pressure through the sinusoids uh into the veins we can see this with tricuspid regurgitation we can see it with moderate to severe right heart failure or pericarditis the exception would be in the young child where the liver is so soft and pliable that it can actually transmit um a cardiac uh uh pulsations uh and central venous pulsations from the heart here is an abnormal pattern of a main portal vein suddenly it becomes too flat very flat and continuous flow with loss of that undulating pattern and that's what we'd see with therosis and hepatic fibrosis where the liver becomes stiff and we lose that undulation the hepatic artery now let's look at the hepatic artery the hepatic artery typically has a very uh rapid systolic acceleration it's a nice arterial pattern uh it has continuous forward flow of of uh blood into the liver throughout the cardiac cycle so it has a low resistance pattern in other words fairly high diastolic flow because blood free enters U the liver it is always in the same direction as the uh main portal vein flow so on color Doppler these two vessels the artery and the main portal vein are always the same color so if you set your color map with red meaning towards the transducer both will be red if you turned it blue as meaning towards the transducer both should be blue but you should not have one red and one blue because of course this has nothing to do with oxygenation its direction it's also interesting that the uh portal vein and the hepatic artery sort of have a mutual understanding between themselves the portal vein carries 70 to 80% of the blood into the liver whereas the hepatic artery only brings in 20 to 30% of the blood flow but the artery brings in the fresh oxygenated flow and the but the portal vein brings in deoxygenated flow from uh the uh spleno uh mesenteric system uh however it's carrying a lot of flow and there is a certain uh homeostatic mechanism between the portal vein and the artery so if the portal vein flow decreases there's a signal given to the artery to increase blood flow so as a liver becomes sicker and and develops more sorosis and blood flow cannot come in through the portal system the arteries tend to enlarge to bring in more flow okay so you saw the normal waveform now here's an abnormal waveform the waveform becomes abnormal when the resistance becomes increased and diastolic flow drops so we we see such a pattern after eating post prandial uh we also see this with portal hypertens more resistance in the liver and more importantly these days transplant rejection we will pay attention to the arterial waveform now another way that uh the artery has abnormal Doppler is uh post liver transplant that's when it becomes important to us if we see a tardis parvis waveform uh it after liver transplant this is an abnormal finding uh we would see low upstroke and a fairly low velocity which means that proportionately the diastolic flow is elevated so we have um a prolonged uh systolic acceleration time uh and then this Tardis parvis waveform what it means is uh that there is a hepatic artery stenosis an asmosis there's a anastomotic stenosis postoperatively so we are not seeing the flow through the stenosis itself but we are seeing the flow Downstream from the stenosis when the flow has lost energy and is trying to relaminarization veins normally the hepatic veins drain towards the heart that's why they're registered here in blue away from the transducer and on the spectral they are also registered away usually below the Baseline towards the transducer where we have syy diast but we have above the Baseline when we have the atrial kick so we have syy diast kick syy diast kick uh the uh normal Doppler here the reason for this pulsatility is because it reflects respiratory phases and variations in central Venus pressure that is transmitted from the right atrium it also reflects the compliance of the liver panma giving us this triphasic waveform syy diast kick uh be careful though because deep inspiration or Val Salva May uh reduce this pulsatility and dampen it causing you think there's a problem so the waveform becomes abnormal when we lose that uh triphasic flow when we lose that we know that there's elevated right heart pressure we lose the oscillations or the amplitudes we can actually uh lose the atrial kick we we lose that first and then the whole waveform starts to be more dampened event ually turning into a monophasic abnormal waveform that is flattened and actually res almost resembles a portal vein flow we call this portalis of hepatic Venus flow so it should be a nice um pulse tile pattern and all of a sudden now it's flow it's because the liver is stiff the liver is non-compliant and does not allow this wave to be reflected um in the vessels so now let's talk about sonographic liver patterns there are basically three patterns in the liver the normal pattern the centrolobular pattern and the fatty fibrotic pattern we already discussed the normal pattern now there's the centrolobular and the fatty fibrotic if you look at it closely this one has too many portal vein walls this one doesn't have any and let's talk about the reason for that in the centrolobular pattern what happens is the liver is emitus so that the prenal uh cells the sinusoids uh the hepatic cells become emitus increase in water drop their echogenicity okay and that makes the portal vein wall Stand Out giving it a starry night appearance so you have these Bright Walls standing out in a dark background of the night sky so what we see we see increased brightness and we of the portal vein walls and we seem to have more portal vein walls now the liver does not make more portal veins it's just that we see them because now we have more contrast this pattern is seen with acute hepatitis also seen with acute right heart failure you may see it with infiltrative uh diseases of Leukemia and Lymphoma we used to see it with toxic shock syndrome but we don't see that much anymore and we can see it with 2% of normal cases and the 2% of normals are usually the young thin adolescents maybe 15 to 20 years old uh they're so easy to scan and see so well that they look uh abnormal and that's easy to tell the patient is healthy there's no liver function test abnormalities uh so those would be normals beyond that uh uh we have to be cautious and rule out um liver disease I would like to bring up fulminant hepatic failure because this is something that's very serious but could easily be dismissed or misdiagnosed you will not see this often but when you see this you should think of fulminant acute hepatic failure and liver necrosis what you'll see is areas patchy areas of decreased echogenicity with prominent portal vein walls uh and areas that look normal they look echogenic but they're actually normal areas of liver you look back at these this is The Starry Night pattern reflecting acute edema or necrosis and these are areas of normal or regenerated liver so they come in patchy areas um this is a case that we recently had of a 22-year-old man uh who came in with uh jaundice and we saw areas of the liver that had increased portal vein brightness and we thought that that looked like acute hepatitis yet other areas of his liver seemed to be normal uh he did have jaundice and uh he was not that sick however he be his Billy Rubin was close to 30 event got up to 30 in the hospital and he became so sick that he ended up with a liver transplant so what happened in this case it turned out that he was um using um herbs certain herbs for bodybuilding uh and apparently developed some kind of uh Toxic effect from these herbs uh and uh developed liver failure and ended up with um a liver transplant I have seen such situations happened one one case was a sulfa drug reaction a woman who was on sulfa drugs for bladder infection who came in as an outpatient and had this appearance so we thought that something was very unusual and wrong we sent her to the emergency room and after I followed her up in 3 weeks I found out that she too went into liver failure and had a liver transplant from sulfa drug reaction another patient that I had um that I recall uh with this pattern was a 34y old woman who was weak uh a little bit jaundice and uh I thought also outpatient setting and I thought gee this livered something's very wrong I sent her to the emergency room and on followup I found out that within 24 hours she was dead autopsy revealed that she went into heart failure she had lupus myocarditis and lupus hepatitis and develop this acute fulminant failure so these are unusual cases nonetheless uh serious and we should not dismiss such an appearance uh if you're not sure if it doesn't look like it um matches the clinical picture uh we should send the patient right away for evaluation the fatty fibrotic pattern is opposite we have increased echogenicity of pranama there's some kind of infiltration with fat or fibrosis going on in the liver which increases the echogenicity high enough that it matches the portal vein walls and the contrast is lost therefore we do not see the echogenic portal vein walls in this pattern uh the uh we we look at the echogenicity that's increased but then we have to look now at the echo texture it could be a smooth homogeneous Echo texture of the pranama or could be heterogeneous or coarse uh sometimes we see sound attenuation and this type of pattern is usually seen with fatty infiltration but also seen with chronic hepatitis and curosis so here's the fatty fibrotic pattern with the homogeneous echotexture here's the fatty fibrotic pattern loss of portal vein walls with the heterogeneous pattern notice we almost see little tiny rounded masses throughout a little bit nodular that's what gives it this heterogeneous appearance let's look at the fatty liver fatty livers are of this pattern echogenic loss of portal vein walls when it it's a a very pronounced case there's so much attenuation that we can't even image the Hemi diaphragm as we have in this case we've tried to increase the TGC curve post cely and we cannot fill in with Echo uh notice how nice and homogeneous this pattern is now fat can do two things focally we can have focal fatty infiltration and we can have focal fatty sparing okay here's focal fatty infiltration where we have areas of fat now the fat part is echogenic fat areas of fatty infiltration inter vegetating between areas of normal liver pranama and we also can have focal fatty sparing here are areas of normal liver not affected by the fatty infiltration you look carefully you see little vessels inside there's no Distortion this is a completely normal little liver pattern uh and uh that's uh areas of normal uh liver spared this can can can possibly be um confused with liver masses however they occur in a very typical location around large portal veins around fissures and subcapsular so we we tend to look in those regions and we look for internal architecture and see that it's not distorted sosis has this fatty fibrotic pattern now when we make a diagnosis of curosis we look for heterogeneous echotexture so coarse sometimes that it looks moth eaten and it's from these little islands of regenerated tissue mixed with disease tissue that causes this uh heterogeneous pattern the livers tend to be small and shrunken they have a nodular surface often there's AES to help us delineate the surface and these are the livers where we can see the enlarged Cotate so if you see an enlarged Cotate to right lobe ratio and if it's over 0.73 that's a 99% specificity for curosis it's not sensitive but it is specific here's a serotic liver try to imagine what you would see on ultrasound you see these nodular areas of regeneration all throughout in between are these fibrotic bands and that gives this uh nodular appearance sometimes micro nodular sometimes the nodules are big bigger and sometimes macr nodular appearance look at these tiny little islands of regeneration inside the liver which cause vascular Channel disruption uh Etc so when we see a cerotic liver on ultrasound we then have to right away look for clues of portal hypertension so with portal hypertension the liver is diseased the liver panma develops resist resistance to blood flow this increases the portal Venus pressure eventually the portal flow will slow down and it will reverse and flow will actually be going away from the liver hepatofugal uh and there's then increased risk of bleeding uh because collateral vessels open up the ultrasound findings of portal hypertension include aites uh a dilated main portal vein splenic vein or spir spe mesenteric vein uh what is a dilated portal vein well a portal vein bigger than 13 mm in diameter we consider dilated a splenic vein or Superior mesenteric vein centrally when it measures more than 10 mm we consider that dilated so just a simple measurement we look for collaterals splen omegal is part of it and various Doppler findings where would we look for collaterals well right away the first place to go is the gastro esophageal Junction uh ge Junction we then can look for a coronary vein which would be a little Branch off the main portal vein or off of the splenic vein uh we would look for a recanalized umbilical vein heading towards the umbilicus we can have gastrosplenic vessels we can have a splenorenal uh collateral we can have a gastro renal collateral we can have Perry splenic uh all kinds of retrop paral collaterals vessels that we don't usually see suddenly appear so we try to look for them on ultrasound here is um the aorta the gastro uh es Sofio Junction GE Junction and tortuous serpiginous vessels in the region these would be um the um gastro esophageal collaterals here is a sagittal section through the recanalized umbilical segment uh recanalized umbilical vein and it has flow heading out of the liver towards the umbilicus hepatofugal flow out of the liver in this image we see the splenic vein which is posterior to the the body of the pancreas and it seems to have a branch we usually never see a branch there but when we see such a branch that's a perfect place for um a coronary vein here's a spleen with large vessels around it uh uh up up in the left upper quadrant perhaps these are gastrosplenic collaterals here's per gastric or perisplenic kind of collaterals here's a large spleen with the left kidney and there's a large torture vessel in between a splenorenal shunt what are the doler findings in Portal hypertension well let's look at the portal veins first of all we're going to lose the respiratory variation the waveforms become very the waveform becomes very flattened we have a drop in the velocity of the main portal vein and eventually it may reverse and be on the RSE side hepatofugal flow hepatic veins hepatic veins start to lose their normal pulsatility we had syy diasty kick syy diast kick and now all of a sudden it's becoming a very flattened waveform hepatic arteries uh the only thing we'll see is that they can become quite large and also notice here on this color image the hepatic artery is red the main portal vein is blue they're opposite colors the artery and portal vein should be the same color this means that the artery is going towards the liver and the vein now has hepatofugal flow so we can see that as two different colors you can also see enlarged hepatic arteries in the panma of the liver and uh what happens in that situation is in the portal Triad you where you have the little portal vein on top of it is dilated a little hepatic artery now also sits there the bile duct usually when we see a dilated duct on top of the portal vein we see this this parallel Channel Arrangement but it can also be seen with a dilated hepatic artery we turn on Doppler one has Venus flow one has arterial flow now the last last uh segment uh that I'd like to talk about the liver is regarding liver masses ultrasound is excellent in detecting focal liver lesions we're very specific we're specific for liver cysts but liver cysts that are about a centimeter or more because very tiny ones we may not be so sure about but ultrasound is not good in differentiating among the different pathologic entities that there are very few ultrasound features outside of cysts that are characteristic of uh the mass itself the pathology we are not good in distinguishing between benign and malignant masses tripleace liver CT and MRI are excellent modalities for this but we are good for picking up a focal mass and we are also very helpful in the diagnosis in the proper clinical setting uh were good for followup and as a guidance for biopsy we can see simple cysts now this is a classical cyst like anywhere else in the body uh a uh anaco Mass smooth margins excellent sound transmission so this is a simple cyst in the liver what else can be simple cyst well an old hematoma uh a hydrated or a kind of coaco apsis which this is this is a patient from Egypt uh who had a solitary cyst and eventually this was diagnosed to be a kind of cockle a Boma or a seroma can look like a simple cyst and if we ever have a vascular uh struct or if we ever have a cystic structure that looks unusual not perfectly round we should always think of the possibility of this being some type of vascular structure like an aneurysm or some unusual fistula like arterial portal Venus fistula or portal to hepatic vein type of a fistula we can have multiple cystic lesions throughout the lever very often these are associated with uh adult polycystic kidney disease or the dominant adult or the dominant uh polycystic kidney disease we could see multiple cysts with ayo is or HED disease as was in this case we can have multiple uh Le cystic lesions throughout the liver that are actually uh kocal cysts the type four and the type five type four has the dilated duct bile duct type five has a normal bile duct but we can see these um uh structures cystic structures throughout the liver if we look at them closely we will realize that they actually connect and these are tortous tubular structures but many times they just look like collections of cysts this is a reminder for you of the kocal cyst the type one has a dilation of the bile duct the type two has a little diverticulum a little cyst uh off the uh bile duct type three has a little Kido seal protruding into the duodenum uh type four has dilated biliary ducts throughout the liver looking like small cysts and it also has an Associated fusiform dilation of the common B duct and type five or coroli disease uh has the dilated inpa ducts but no dilation of the common bile duct so these types you can see and it's these two that would have dilated um uh cystic type structures in the liver complex cystic masses what about uh cystic masses with Echoes inside of them well that could be from a hemorrhage within a cyst it could be from infection in a cyst uh it could be a hematoma in the liver could be an absis in the liver notice that there's sound through transmission so we know that this is of a cystic nature in this case this was a an absis it could be a Boma or seroma could even be a large uh bil cystadenoma or could be uh cystic or necrotic degeneration within a metastasis or a malignant tumor liver apses sometimes um cause trouble in diagnosis a liver absis when it has fluid and debris is fairly easy to spot but when it has bubbles of gas or pockets of gas that sometimes may Shadow out the back wall of the absis itself and may uh cause confusion in its appearance here's another way that an apsis can confuse us an apsis completely filled with pus uh can uh be echogenic and uh sometimes ISO look ISO eoic with the liver and it may actually mimic liver and you may not recognize it but your eye then would catch some effect on a vessel perhaps you may catch an edge effect from the curved surface and you would eventually realize that there is an absis here uh within the liver this is a fairly characteristic appearance if you saw a cystic mass in the liver and you saw this kind of folding L membrane referred to as a um the uh Lily Pad sign this is the sloughed internal membrane folding in upon itself very characteristic of an ayal cyst if you see this you may be the first one to suggest this diagnosis uh patients travel these days to various parts of the world and may bring back a souvenir uh and a kind of cockal cyst uh and nobody may think of it until the characteristic sonographic picture uh is presented other uh complex cystic masses uh can occur we can have benign we can have malignant this happens to be metastases that are complex cystic lesions uh this one is in a kind of cacal cyst with internal debris this one metastases so we can't really tell there's nothing specific so that's why I'd like to make um just uh a list of hypo eoic masses in the liver nothing very specific about these we can have an absis we can have an adenoma focal nodular hyperplasia a hemangioma an unusual atypical Hemangioma uh focal fatty sparing micro abses they can be hypoc coic it could be a malignant metastasis hypocellular carcinoma or lymphoma we can't tell this happened to be a case of focal nodular hyperplasia uh proven I'm sorry this should be hyperplasia hyperplasia and this was proven by um MRI we uh see in the literature uh that uh focal nodular hyperplasia uh has a central scar however this is not diagnostic it's fairly characteristic but it is not Diagnostic and here's why I'd like to show you here's a lesion with a central Scar and this was a hepatocellular carcinoma this was a lesion that seemed to have have a central Scar and this ended up to be a giant Hemangioma so you see even that Central scar uh is not characteristic enough to be 100% diagnostic we also have lesions in the liver that are homogenous and Hyper eoic and most of the time they are hemangiomas both of these are but we have to be very careful there are other lesions that can look exactly like this that are not hemangiomas hemangiomas when they are found incidentally in asymptomatic patients and in a young patient a patient under 40 well such a lesion we can call a Hemangioma if it's under 3 cm but if the patient is older Beyond 40 or if the patient has any other medical illness we have to then uh prove this to be a Hemangioma let me show you some atypical hemangiomas this is hemangioma atypical heterogeneous this one has some cystic spaces this one is not totally hyper eoic this one is hypo eoic and has some sound transmission all of these are hemangiomas but they're not typical now let's look at something hyper eoic what's the differential of a hyper eoic lesion in the liver well we all know about hemangioma but it could possibly be an absis it could be an adenoma could be focal nro hyper should be hyperplasia it could be focal fat could be a hemorrhagic cyst and it could also be something malignant could be a metastasis could be a hepatocellular carcinoma could be lymphoma not very specific all these are unusual but this one happens to be a thyroid cancer metastasis so you see nothing is 100% in the liver now when we talk about um multiple solid masses in the liver the differential diagnosis is metastasis metastasis metastasis but there are other uh pathologies that can mimic this that can be just the same usually we would say metastasis and we would want to have a history to see what's going on but it's still even in this case not 100% we can have regenerating nodules in a liver in curosis like this patient had and this patient has lymphoma masses within the liver so even solid metastases are not 100% here's another patient with multiple focal hypo eoic masses and this was multiple atypical hemangiomas and this one with small hypo aoic masses was micro abses in an imuno compromised patient so multiple hypo coic solid masses is not always metastatic disease some metastases are calcified and we usually think of them as coming from uh colon cancer but there is a whole laundry list of other cancers we can see calcified metastases with ovarian cancer breast cancer stomach cancer pancreas a OS saroma liom myosarcoma condr saroma teratocarcinoma so certainly uh not a specific appearance what's very useful with sonography is that when we're not sure we need a tissue diagnosis we can just guide a needle straight into the mass and get a biopsy or provide drainage if it's an absis and that's extremely useful uh before I close I just would like to remind you that when you have a case of liver metastasis you should always think a little further to see are those metastasis causing any complications such as segmental bilary obstruction uh you should double check the vessels are the metastases invading vessels uh is there invasion of the portal vein is there invasion of hepatic veins this is a patient who has um hepatocellular carcinoma in the left lobe and tumor has grown into the main portal vein tumor thrombus you should look for necrosis maybe uh hamage or some kind of super infection these are all possible complications of liver metastasis so in conclusion we have discussed uh the appearance of the normal liver we've talked about Normal and abnormal Dopp patterns of hepatic vessels we've covered diffuse um liver disease patterns uh in we've talked about portal hypertension and discussed focal liver metastasis uh thank you for your attention