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Contrast Enhanced Ultrasound - Testing the Waters

Dec 01 | 1:30 PM

Join us for another exciting IRIA, Kerala turf expansion programme with Dr. Eesha Rajput. Dr. Rajput will discuss contrast enhanced ultrasound & how it is redefining traditional ultrasonography around the world by dramatically improving diagnostic sonogram precision and widening the clinical spectrum of a commonly used and easily accessible imaging modality.

[Music] good evening and welcome all we are back for the first expansion program on metrics platform organized by kerala iri after a few weeks gap this is a platform organized by ira kerala aimed at providing amazing content for budding radiologists and making cme and conferences of iris more accessible to all the consultant radiologists across the country we all be booked and are all available at amazon she is also have having a regular forecast on various subjects of importance to radiology doctors residents women children and for the society for this evening we have our central council member professor dr mr balachandra nayasa who also was in the defense for a long time and now the head of department of radiology in july medical college this year he is also the president of chapter of ira kerala and i invite sir for the opening remarks thank you professor judy as part of the tough expansion program today we will be discussing on contrast enhanced subtle sound as you know contrast enhanced ultrasound is now widely used it is very safe and its application is there in many diseases and sometimes most of the time is also a problem solving method to discuss these things we have uh surgeon commander dr isha rashford associate professor at the inh's ashwani bombay she is a very talented and committed teacher and she did her we all know she had done a lot of cmes and vivina's with ira kerala crust and all but still for those who have not heard about her she had done her undergraduate and postgraduate course from the prestigious armed forces medical college as a student she got many gold medals in various subjects and now she is a registered researcher and she had ordered i think five textbooks four in radiology at this age and service we all feel proud of this great work she has done i'm sure you will all enjoy the uh evening listening to her and now i request dr ishta to take over and conduct you thank you so much sir thank you dr judy and dr valaser for those sincere and kind words they mean a lot to me so starting with the presentation so very good evening to all the delegates who have spared their time to come and attend this lecture today on contrast enhanced ultrasound testing the waters i am dr isha rajpu i am a radiology educator and my prime interest in is in teaching and learning radiology and towards this end i have authored multiple textbooks on radiology and it is primarily for residents chest radiology and diagnostics musculoskeletal radiology orbs and kyani radiology and the recent one that is cornerstones of radiology and diagnostics basics and beyond all these books are uh appropriately priced and placed on amazon and flipkart for the benefit of residence alone so starting with today's lecture nothing uh starts without uh thanking your seniors and your teachers so i thank surgeon captain rochan panth my guide uh for guiding me through radiology and my current edu sergeant captain rajiv shivshankar who is helping me out to find my path further in the same field my colleagues and juniors at anders ashwini mumbai my gratitude to dr heman patel sir who has been a light for me in this field dr manatsa dr sikander sir dr bharara prasad sir all of them need no introduction past and president office bearers of iris seniors and colleagues at iran thank you so much for guiding me through this field and amazing field of radiology and i love being here and also to start with i thank iria kerala the whole team for giving me the opportunity to to present today's lecture right so this is my discussion road map for my discussion on contrast enhanced ultrasound the introduction part and then why every time when you start a new thing or whatever you want to do with your field or your professional expertise the first thing that you need to answer is why you are doing it what is your motivation or what you will achieve by trying that modality will it give you a benefit and upper edge over the other things next we will discuss the technical essentials that are required before you start performing contrast enhanced addressing you should understand the physics behind everything in radiology the fun and joy becomes much more after that then i will discuss the ultrasound contrast agents that we need to use to perform the contrast enhanced ultrasound the safety profile and contraindications of the scene limitations yes everything has limitations and so does the ultrasound contrast agents which will be discussed after this basics i'll go about explaining the specific applications um case-based discussions in liver kidney spleen pancreas vascular applications and ending with a discussion a brief discussion on what the future of contrast enhanced ultrasound looks like this will be followed by two videos which i have recorded in my department itself and which will show you the utility of contrast enhanced ultrasound so let's begin the contrast enhanced ultrasound is not so novel a modality it was introduced in 1990s and the approval for liver application however came very recently in 2016. the enhanced contrast enhanced ultrasound or from now on i'll refer it to as ceus contrast enhanced ultrasound briefly it has the inherent benefits of any ultrasound modality that is real time portability the low cost of equipment but and also in sometimes when the patient is critically ill shifting is not possible or there is a significant language barrier present the only viable contrast imaging option that you have at hand is cus ct and mri may not come so handy at that moment so the indications of cus include the characterization of indeterminate lesions detected at baseline ultrasound all of you would agree with me that ultrasound is the one that is our bread and butter we do it day in and day out but there are some lesions which remain indeterminate at our regular ultrasounds at that point of time contrast enhanced ultrasound comes very handy another case there are some lesions that remain indeterminate in spite of performing triple phase or all the phasic imaging on ct and mr for such indeterminate lesions again contrast enhanced ultrasound gives us a hand to hold the third thing is when intravenous contrast material is necessary but iodinated or gadolinium based contrast agents are contraindicated so what is this case of course in cases of renal failure and patients who are suspected to have any any amount of renal compromise then you would not like to expose them to iodinated or gut based contrast in such cases intravenous uh contrast enhanced ultrasound will be the only option and yes it definitely now is a very viable option apart from these three indications uh the us fda food and drug association of u.s has these approved uses of contrast enhanced ultrasound that is characterization of focal level lesions in both adult and pediatric patients and evaluation of the psychourital reflux in pediatric population so these are the usfda approved indications and the above and three are the general indications for which we use ceus right so as i had told you that why should be very clear why you are using cus it is is it safe is it giving you a higher edge over other modality or is it your only option right so we start with the first why first answer to our wife contrast enhance ultrasound has the highest contrast resolution now what do you mean by highest contrast resolution that is when you are exposing the patient to a contrast agent the sensitivity to the contrast agent is maximum in cus it allows visualization of individual micro bubbles the concept of micro bubbles i'll explain in when we are discussing ultrasound contrast agents these are micro bubbles that are used and in cus they measure around 1 to 10 micrometer the visualization is very sensitive for these micro bubbles now what is the property that is helping us the differentiation of true vascular tissue from debris or blood clot in various applications like distinguishing between neoplastic and non-neoplastic complexes like in kidneys or tumor thrombus from bland thrombus in these applications the inherent contrast resolution come becomes a very big benefit for cus another thing you just think about subtraction images add dynamic contrast enhance ctn mr so you only get the contrast images uh which you can only get and get to see the contrast and rest of the tissues are subtracted something similar happens in contrast enhanced ultrasound because what happens is the micro bubbles that are used for detection they not only selectively show the contrast agent but they also cause suppression of the background signal so this is one very important uh upper edge that we get by using contrast enhanced ultrasound the second answer to why real time now real time imaging this is not there in any other modality in ct or mr which are the viable cross section imaging options the detailed visualization of vascular morphology and pattern of contrast agent dynamics pattern of contrast agent dynamics means it i am referring to the washing and washout characteristics when we are trying to characterize any lesion for malignancy for example in the diagnosis of hepatocellular carcinoma now all of you must be thinking that we are also already using triple phase imaging in ct and mr to characterize hcc as compared to other lesions so how come ceos is more important or it's giving us an upper edge what happens is that uh when we take a patient for ct and mr most of the time we do put bolus tracking technique but the cardiac dysfunction that the patient may have related to age or other problems that may cause us to miss the correct phases for desired enhancement but when we take the case of contrast enhanced ultrasound we have real-time imaging so this factor removes circulatory variation in the optimal phase time so that cardiac variation and circulatory variation is removed by the fact that contrast enhanced ultrasound is a real time imaging the second thing is also that it has a very high frame rate around 10 to 15 frames per second so the motion artifacts arising from respiratory motion and cardiac pulsations that is completely removed so real time is one big factor that gives us contrast enhanced ultrasound and upper edge the third answer to our why is intravascular property the purely intravascular property now what i am going to explain here is very important this concept you should embed in your minds that almost all ct and mr contrast agents are small molecules right so they start to exit the intravascular space immediately after injection so when you are injecting the contrast agent initially it remains within the vessels but slowly it starts getting into the equilibrium phase what is the equilibrium phase the on injected contrast material and the extracellular fluid space concentration those becomes starts becoming equal that is known as the equilibrium phase now you know that in many malignant tissues and inflammatory tissues the permeability of the membrane increases so what will happen this equilibrium phase is gained even much faster so the lesion may show early enhancement but slowly in equilibrium and delayed phase it will show persistent enhancement because of increased permeability of the cell membrane of malignant or inflammatory tissue but what happens in the case of contrast enhanced ultrasound these micro bubbles are larger they do not leave the vascular space because of their size so they remain in the blood space because of this feature the arterial enhancement and washout characteristics is much much better displayed as compared to ctnmr the washout of contrast agent that means negative enhancement related to the surrounding parenchyma is much consistently shown in contrast enhanced ultrasound so the same fact is being reiterated in this diagram the upper diagram a and b they are showing the contrast ultrasound agents micro bubbles coming into the interstitium coming into the blood vessels and then in b image it is the concentration is decreasing but it is still staying inside the blood vessels it is not leaving the intravascular space comparison to c and d now in the ct and mri contrast agents are injected into the blood vessels and in the interstitial in the equilibrium phase that is diagram d because of increased permeability of cell membrane or because of malignancy or inflammation or otherwise there is an equilibrium phase that happens and the contrast leaves the intravascular space this may be the reason for persistent enhancement or not so clear wash out characteristics as compared on contrast enhance understand so with this concept being clear let's go to next answer to y so till now we have had three and this is the fourth answer repeated visualization can you perform a contrast scan immediately after you have done one in the morning i'm sure you all of you who have worked in your departments in city and mr know that you cannot repeat your contrast examination even if the patient's renal parameters are absolutely normal you cannot uh you cannot take the uh risk of um of doing taking the patient uh again right so repeated visualization cannot be done in cp and mr but contrast enhanced ultrasound allows you for repeated visualization of vascular patterns how there is a disruption replenishment technique now what is this these ultrasound micro bubbles are routinely visualized by using a low mechanical index setting now what is this mechanical index i have introduced a new term i have not explained it till now in my presentation i'll do it in a brief while so when we are doing contrast enhanced ultrasound we use a low mechanical index by briefly turning up the mechanical index to the normal grayscale levels we can cause the disruption of all the microbubbles we can make them burst so these microbubbles will burst and they will clear the insulated field immediately we can give another injection and we can evaluate this either the same lesion or even other lesions which are if they are multiple we can evaluate them at leisure how do we do it i'll explain it right so safety profile and contraindications by just the matter of fact that i've just explained that we can immediately repeat the contrast enhancer ultrasound you can understand that how safe it is the contrast micro bubbles are inert gas coated with lipid for stabilization adverse reactions are rare and mild no renal excretion or toxicity is associated there is category b for pregnancy this is an important mcq question please remember the contrast enhanced ultrasound agents are category b for pregnancy they given the lack of studies in pregnant women the only current contraindication is a history of hypersensitivity because uh two microsphere components the components that are used to stabilize the shell if some hypersensitivity to them is the only contraindication which is an unexpected or unpredictable event normal mild adverse effects that have been reported include altered taste headache and nausea the limitations now what are the limitations to this uh supposedly uh very useful modality that i have mentioned the upper right of the diaphragmatic region of the liver now this part of the liver is very is sometimes very uh difficult to approach with serotic and small nodular levels so even with ultrasound if you're not able to see a lesion in the right sub-diaphragmatic region of liver then contrast enhanced ultrasound is not going to help you in the visualization so that you must remember that in small serotic levels the upper right side sub diaphragmatic region is a difficult place to go in nodules located deeper than 10 centimeter this is important because uh if the distance from the probe surface is more than 10 meter centimeter either because of the patient's body habitus uh then contrast and handle ultrasound will not have adequate beam attenuation to give you a good image then assessment of washout in a severely fatty liver this is even a problem in ct as well because of the liver is very fatty then wash out characteristics determining the washout characteristics is difficult and same remains in a contrast enhanced ultrasound so let's discuss how do we do it the procedure how do we do a contrast enhanced ultrasound so whatever equipment you use you cannot use it in uh equipment a regular equipment your ultrasound machine should have contrast material specific mode which should allow imaging of non-linear signals from micro bubbles now again i have introduced a new word non-linear signal this this i will also discuss what we use in our c u s is a low mechanical index 0.05 to 0.3 this i this sentence i have said two three times that we use a low mechanical image why low mechanical end is to minimize disruption of micro bubbles currently sulfur hexafluoride lipid type a microspheres and perflutrin lipid microspheres can be used however the contrast agents that are available in india i'll just mention in a while bowler's injection of the contrast agent is given approximately 2 ml and followed by a 5 to 10 ml normal saline solution flush so you have to use a three-way attach it to the iv line uh same time you have to inject the 2 ml of contrast ultrasound contrast and followed by a 5 to 10 ml of normal saline solution flush i use a 10ml normal saline flush the dual screen mode has to be used which should show which should show a contrast only display also and a b mode display also and the lesion has to be kept in imaging plane at all the times so how much how long you have to perform imaging has to be started either on video or intermittent mode it's better to image continuously for the first 60 seconds after contrast injection after 60 seconds you can perform intermittency every 30 or 60 seconds until force to 6 minutes after injection and this recording can be seen frame by frame after the contrast material has washed off now after i have explained the technique to you let's now discuss the contrast agents here i'll discuss what all is available in india how to use it what are the indication contraindications what are the side effects and what is the difference between first generation and second generation contrast agents right so contrast ultrasound contrast is just a bubble so these are micro bubbles of the size 1 to 10 micrometer containing air or other gas within a shape when a contrast agent is administered it enhances the back scatter of ultrasound so again an mcq question please note what does an ultrasound contrast agent do a increases the background back scatter of ultrasound b increases resonance of ultrasound c increases depth of ultrasound d increases frequency of ultrasound so option will be back scatter of ultrasound right so keep this in mind the mechanism of action of an ultrasound contrast agent is increases the back scatter of ultrasound by resonance within sonic windows so what happens is there is marked amplification of signals from blood flow now ultrasound is used to image tissues doppler is used to image blood flow but not microvasculature for microvasculature you need contrast enhanced ultrasound now we come to the most awaited mechanical index i have been referring to this word again and again and it just means a peak rare fractional pressure the pressure that you are applying on the tissue divided by square root of the ultrasound frequency that you are using so this is the definition of mechanical index the peak rear fractional pressure divided by square root of ultrasound frequency so ultrasound frequency you already know that you are using on your machines and peak rear fractional pressure divided by by the square root of frequency that gives you the mechanical inputs and when you are doing a grayscale imaging the mechanical index that you are using is one so on most of the examinations that you are doing every day in your departmental settings the mi that you are using is one now the mi is related to the insulation type so at the mi that we are using in grey scale is one and it is related to the insulation power of the microbubble within the ultrasonic so when the mi is low then when the mechanical index is low meaning the pressure that you are applying on the micro bubbles is low then the microbubbles will remain static and they only help to increase the back scatter of the ultrasound beam but where as you start increasing the mi as you start increasing the pressure that you are applying on these micro bubbles slowly they will start resonating they'll start moving so first in initial initial part they will resonate linearly till about mi of 0.2 then they will resonate non-linearly but in mi of 0.2 to 0.5 in cases where the mi is more than 0.5 mi is now increasing right so then these micro bubbles will oscillate strongly strongly and then they'll expand beyond their limit and then they'll disrupt they will burst so these contrast enhanced ultrasound images can either be created from the signals of non-linear oscillation or the signals of bursting destruction right so the linear oscillations will not help you in contrast enhance ultrasound either the non-linear signals are will generate an image or the bursting of the micro bubbles will generate an image so how we are using this in first and second generation let's go about now a little bit this will be a little bit and it looks like a busy slide and it's going into too much into physics but don't worry i am here to make everything simple for you right so till now what we have discussed is that the all micro bubbles oscillate in linearly non-linearly and then they burst linear signals at low mi the problem with what is the problem with linear signal why don't we use linear signals for contrast uh ultrasound image generation because these signals are generated from the contrast agent also and from the surrounding tissue also and we cannot discriminate between them that's the problem that's the second line of the slide that says that the third line says non-linear signals which are generated by ultrasound contrast agent these can be separated very nicely because these agents are operating at a low mechanical index so when we operate at low mechanical index the images that we are generating is from non-linear signals so let's just only read the yellow line because non-linear signals from the tissue and the ultrasound equipment are proportional to the mi the second generation contrast agents which use low mi they offer an advantage by decreasing the non ultrasound contrast agent signals whole this long sentence means only that when you are using an second generation contrast agent because of presence of low mi there is easy detection of non-linear signals from contrast as compared to the surrounding tissue so what is the funda of generation of image from second generation contrast agent is non-linear signals as compared to that the first generation generates its contrast image from rupture or disruption of microbials this i will also discuss in just a while let's first discuss the generations of contrast aging the generation of contrast agent depends on the criteria that differs between first and second is just the type of gas that is present within the microbubbles i'm sorry for the small form but i hope you'll be able to pinch to zoom in so first generation only one agent is there livo vest that was introduced in 1996 this had air within a shelter of galactose micro particles also stabilized by a bit of permittivity so what happened with liver west was that when it was intravenously administered uh it distributed itself within the blood tool but in two minutes it also uh gave us the liver spleen specific phase right the mechanism for pick up for liver strain specific phase is set to be the same as in technetium colloid uh scan or spio scan in reticular endothelium system in mr right so the same mechanism is said to be operating here as well the particle size was always less than seven micrometer so this could easily pass through the capillaries of the lung and then go to the heart and help us to generate ultrasound images so what was the problem with first generation that we went on to second generation the problem was that these were not stable particles so now um we had to do the image generation only by bursting the particles and this was uh being done you could not do it real-time imaging you just had to recall and then images could be viewed frame to thing so the problem was that to stabilize these agents so for stabilization two things were right first was people tried to stabilize the shell that didn't work out so the second thing what they tried was use some gas which is much more insoluble as compared to air and it should be more inert that was the idea so the type of gas within the micro bubble shell that changed from first generation to second generation in first generation it was air and in second generation there were different compounds that were used as i will tell you now so the examples of second generation are sono view definitely octison sonazoid right remember these phonemes sono view definitely optison and sonazoid so again an mcq is generated here uh all of these are second generation ultrasound contrast agents except sono view definitely optison and livo west so answer will be then i'll tell you answer will be levo west right so uh definitely consists of octa fluoropropane gas within a lipid shell optician consists of octa fluoropropane in an albumin shell solar view consists of sulfur hexafluoride within a phospholipid shell this is what i am using here now again one question is that what are the ultrasound contrast agents which are being used in india so only sono view and definitely is available in india sonazoid is available in japan in korea and optison is available in other western countries right so this is also an important mcq question only solar view and definitely are available in a little bit more about sono view because i am using it sulphur hexafluoride in a phospholipid shell it comes in a packet like this as shown in the image there are uh ultrasound micro bubbles in a powder form and there is a saline to mix with it and then you have to shake it till it contains a it gets a white color then you have to attach it in a three-way and inject 2 ml of contrast followed by 10 ml of normal saline flush good contrast agent does not interact with any other molecule and after the destruction of microbubble the sulfur hexafluoride is excreted only through the lungs so there is no excretion through kidney or liver that's why it is a safe agent another question in mccoos is how do the ultrasound contrast agents get excreted through lung liver kidney brain answer is lungs okay because this is just air or any other gas which is stabilized in a micro bubble shell the shell consists of a monolayer of amphiphilic phospholipid as the outer side of the shell which is in contact with blood it has hydrophilic properties and it is stable so it was initially approved for evaluation of heart and microvascular structures and microvascular structures liver and breast followed but currently the cardiac application has been temporarily suspended by european medicine's agency sonazoid sonazole is available in japan and korea sonazoid has as the diagram shows it has a perfluorobutane gas with a hydrogenated egg phosphatidylserine shell okay so it has heps shell so the a little bit of contraindication is that people who are sensitive to egg protein this is a difficult uh contrast agent to be used here right right so the difference between the two generations i've explained you that first is uh uses air in the uh shell in the microbubble and the second one is using some other gas which is more insoluble and more inert now the second difference so high mi what is the normal mi that we operate in on gray scale it is one so still high mi is point more than 0.7 this was used for first generation ultrasound contrast agents and the this high mi technique is used to destroy the micro bubbles to cause their bursting hence the continuous accusation of ultrasound images is not possible only intermittent scanning can be done for a few seconds and images are recorded and this you can view uh frame by frame later but uh you can again give the contrast and again record the images till you are satisfied with the kind of video or footage that you are getting in comparison the low mi technique where the mi is less than 0.3 this can be applied to second generation ultrasound contrast agent and you can do continuous real-time scanning so in this you need not a stop in between your scan and again inject the agent no that is not required you just keep recording for 60 seconds continuously and after 60 seconds maybe every 30 seconds three or four times till you can see the wash out from the lesion the contraindication sono view has a few contraindications in the form of acute coronary syndrome or unstable streaming heart disease pulmonary hypertension and control systemic hypertension ards all this has been reported and in view of in light of this eco has been temporarily suspended with contrast enhanced ultrasound agents sona's oil as i told you uh has similar side effects as uh as sono hue does and it should not be uh if it must be used with extreme caution in patient with egg allergies as i told you because it has a shell made up of hepas so again an mcq question which one of these should not be used in patients who have egg allergies optison sono view sonozoid definity so the answer is sonazoid okay because the shell is made of hps sodium now because the safety of sono view and sonar zoid has not been evaluated in pregnant women and people and women who are breastfeeding or patients younger than 18 years of age that's why ultrasound contrast agents should be avoided in these patients right so now that we know uh in detail about the modality and technical considerations the contrast agents safety limitations mechanical index and physics all that is done and dusted so now we come to the indications and what is how does it actually help you out in differentiating lesions uh so that you can use it in your departments so the first thing uh the that comes to your mind is benign versus malignant lesions so that key to differentiation is washer so if you see a washout you definitely uh would think that it is a malignant infusion with neovascularity and the washout is seen as negative enhancement compared with the parent kind so uh ultrasound contrast agents being a purely intravascular they show the washout feature much more consistent and sustained enhancement on contrast enhanced ultrasound strongly suggests a benign lesion so let's discuss this case now dynamic enhancement patterns of liver lesions are mostly concordant according in between ultrasound ct and mr modalities but sometimes discordant cases occur in uh diagnosis like phalangeal meds or lymphoma so this was one such case reported in literature there is a mass as you can see in a 23 year old woman uh this is arterial phase and prolonged enhancement on uh five minute delay so as where the arrows are pointing in a and b you see that the lesion was hypo enhancing on arterial phase but on delayed phase it is showing prolonged enhancement right you see the contrast enhanced ultrasound images in the lower row in the lower row you can see that the images were taken on 10 seconds 16 seconds and 3 minutes delays there is early enhancement of the lesion and there is rapid washout so this is highly suggestive of malignant had you only done the uh and post contrast mr and uh done away with contrast enhanced ultrasound there there would be a doubt always in your mind that did i do a right thing calling it a benign lesion or did i do a right thing by calling it a malignant one but contrast enhanced ultrasound if you correlate both the modalities it should leave no doubt in your mind the second indication is hcc versus non-hcc malignancy now again i'm going to introduce an important concept so please concentrate now arterial hypervascularity of varying duration happens in many malignant lesions but what is a timeline of washout how much is vascular is the lesion that is important and when we are looking at liver lesions there are two types of lesions one is hcc and second is either metastasis or cholangio polangio carcinoma in most of the cases so there is a stark difference in enhancement and washout characteristics in these two groups what is the reference fcc see the third line of the ppt uh slide hcc has different washout features from those of non-hcc malignancies the washout of non-hcc malignancies like mets is rapid washout is rapid within 30 to 50 seconds and mark whereas hcc washout is much mild and much late so it is delayed and mild washer let's look at the cases because a picture speaks a thousand words so let's look at the cases now here is a htc in a 58 year old even if i don't tell you the diagnosis now just see the lesion there is a hepatic mass with showing early contrast enhancement in a 15 second contrast enhanced ultrasound now 15 seconds may it is showing arterial enhancement then a light degree of wash out two minutes and a little bit more wash out at three minutes but it is not very well defined and there is not a starved washout and how much at how much time the washout is happening 3 minutes 56 seconds so see we have seen it intermittently every 30 seconds after till a period of 4 minutes approximately so this is the time that we are getting a washout in hcc compare it with this case now above images are the ct images arterial phase where you can see a very ill-defined lesion which is bounded by black arrows arterial phase it is showing hyper enhancement so is in the delayed phase but the second set of images of contrast enhanced ultrasound are showing intense vascularity or intense hyper enhancement on 26 seconds on 16 seconds sorry and just in 26 seconds is showing a stark washout with a relatively well-defined margin so this was a non-hcc malignancy a case of cholangio a distinct difference in typical washout profile between hcc and this lesion so hcc the contrast enhancement and washout is much delayed and it is much less marked but in non-hcc malignancies like metastasis and cholangio the arterial enhancement is intense and washout is quick so this concept please remember for contrast enhanced ultrasound right the third thing is characterization of hypervascular lesions so what are the hypervascular lesions you are thinking of when you are doing a liver scan you are thinking of hemangiomas and fnh now sometimes hemangiomas you may miss on ct or mr if you're not doing a proper bolus tracking or if the patient has a cardiac dysfunction which makes you miss your bolus track but see contrast enhanced ultrasound then comes to your save the above image which has two white arrows you can see that uh you have a t2 and t1 weighted image in which you can see a nodular serotic lever and there is a mass approximately four to five centimeter sized bounded by the white arrows t2 may it is hyper and t1 mate is relatively iso so how do you characterize it looks like a liver mass it looks like maybe an hcc it's a nodular serotic liver who knows though so that it was decided to do contrast enhance ultrasound and on contrast enhance ultrasound at 12 seconds and 5 minutes what you can see is 12 seconds image shows that peripherals nodular enhancement with centripetal filling in and at 5 minutes it is completely filled in so definitely indicative of a hemangioma so this puts you at the rest that this is not a liver uh malignancy right so many hearts so much love thank you so much right so we go to the next hypervascular case fnh concentrate on images a b and c don't read what is given on the slide just listen to me and see the images abc okay so we have here an mr image excel t2 and uh post contrast images initial arterial phase way it is showing a hypervascular lesion that is enhancing if you go into portal venus phase it is still showing enhancement and on a delayed phase with the 2r delay it is showing a bit of washout in the center the overall pattern definitely i would not say it is a finish and i would more be thinking about maybe an infective etiology or a metastasis but if you perform the contrast enhanced ultrasound for the same patient 12 seconds pay you can see this small artery that is lighting up in the center and 13 seconds and 15 seconds a central stillate like a comma shaped archaea or vessel is seen with centrifugal progression of enhancement which is definitely characteristic of fnh so even if you don't see the scar in the center on contrast enhanced ultrasound you can definitely see the stellate artery and centrifugal progressive enhancement which tells you that this is definitely not a metastasis because it's not showing a washout wash out here and it's showing the progressive centrifugal enhancement with a central stellate archery so this goes in favor of fnh now so when we have patients at high risk for hcc ultrasound contrast enhance can be taken as one stop assessment for such false positive results like hemangiomas again you can very well differentiate between hcc and non-hcc malignancies by going along the timeline non-hcc malignancies will enhance fast markedly and show wash out fast and hcc will enhance and show washout milder and later hemangioma nodular peripheral beetle filling in and gradually it completely enhances effingh central stellate archery with centrifugal progressive enhancement so this puts you at so much advantage that you can with one simple injection of a contrast agent in your ultrasound suit you can with definite amount of confidence you can tell the patient whether he has a malignancy or this is just a benign hemangioma which has to be left alone now the next important uh use of contrast enhanced ultrasound is bland thrombosis versus tumor thrombosis now many patients who come to us many times with total venous thrombosis who have already been diagnosed with hcc or any other malignancy it's very difficult to differentiate between bland thrombus and tumor chambers even with well targeted ct and mr images so and if you ignore tumor thrombosis in portal vein this has a decimal prognosis so here arterial new vascularity which is seen with contrast enhanced ultrasound comes very handy see this case in an old patient of hcc baseline image was showing us this uh there is ecogenic filling or defect which is seen in the portal vein and you give contrast ultrasound contrast and it just lights up much lights up much before any normal portal venous enhancement so definitely this is going in the favor of a tumor thrombus right so next case that we have is post ablation follower now many patients who have undergone rfa procedures uh it is difficult to assess them on ct or mr for recurrence because when do you do rf ablation procedure the adjacent day areas near the lesion they develop arterial portal shunting so they seem to be very hypervascular so it's very difficult to say whether it's a recurrence or it's just a side effect of rf ablation let's check out a case now see the ct image right so it has faint small small arrows and there is a hypodensity which is seen in the periphery of the liver now you can expect this location to be uh the rf zone rfa zone short arrow is showing the rfa zone and what is this hypo intensely hypo dense lesion that you are seeing here in ct there is an area wet shaped area of hyper density and there is a lesion that is hypotense what are these it's difficult to say on ct but let's perform a contrast enhanced ultrasound and then we see that black arrow is showing some hypervascularity some arterial phase enhancement the white arrow is showing completely hypervascularity which is likely the site of previous rfa so here there is no lesion there is no vessel so there is no vascularity the black arrow shows yes a cup of ultrasound agent what is the star showing star is showing area of arterio portal shunting here the complete vascular architecture has been disrupted because of the rfa treatment and this will cause you lot of diagnostic dilemma but you have contrast enhance ultrasound with you so you see at a few seconds and within a two minute delay there is a washer so as you see in hcc there is a washout at around 122 160 seconds that is a two minute delay it uh washout is late and not that stark so this would suggest definitely a site of hcc recurrence and this you can also help out if the lesion has to be targeted for biopsy this would become very handy in that so now till now we have discussed the liver applications of contrast enhance ultrasound now let's go to other indications other organ systems non-hepatic organs so renal and urinary tract the similar indications that we had in liver we have in kidneys also differentiation of neoplastic from non neoplastic cysts how to identify a small indeterminate mass impaired graph function surveillance after radio frequency ablation and urinary tract tumor differentiation from a blood clot in gb also to differentiate sludge from neoplasm and in pancreas assist from a cyst-like tumor cystic tumors are very common in pancreas as all of you know when vascular system to see an endo leak and tumor thrombus from bland thrombus this i have already discussed so let's quick have a quick uh review of few cases of non-hepatic indications of contrast enhance ultrasound thank you i can see most of you are alive till now so that's a very good sign let's discuss the last few cases so here we have a complex renaissance that is seen on grayscale imaging the left side image it is also showing a solid nodule within so this is likely a complexist how to exclude malignancy if this is an elderly man definitely malignancy has to be on our cards so we perform the contrast enhanced ultrasound and we can see that there is the cyst is completely avascular there is no enhancing element within the cyst which suggests us that this is a non-neoplastic lesion another example there is a cyst on mr that we can see in the image in kidney now what is this is how do we do how do we decide we do as contrast enhanced ultrasound the simplest procedure around and we see an enhancing peripheral nodularity with thick scepter that is shown by white arrow so this definitely becomes highly suggestive of malignant a third case short a small tumor how do we identify on grayscale you can see a small lesion in the kidney we do a contrast enhanced ultrasound and shows stark washout right so stark washout whenever it comes you definitely suspect of malignancy and the lesion showed capillary rcc on malignancy uh papillary rcc on biopsy sorry okay so next case we have gallbladder indications this was an incidental abnormality picked up on ncct image done for some other reason so there was internal heterogeneous content that was seen on grayscale ultrasound uh heteroechoic lesions with the calculi it could be a sludge or tumor how to decide so contrast enhanced ultrasound comes handy and when we see a definite enhancing irregular mass lesion within the gallbladder definitely our suspicion of malignancy was very high intra luminal capillary adrenal carcinoma of the baldness right last few cases just finishing up backing up we have a splenic lesion which is on gray scale relatively well defined according second image contrast enhance ultrasound early phase that is showing fast pick up hyper enhancement and this enhancement is persistent there is no washout right so if there is persistent enhancement on contrast enhanced ultrasound this in keeping with the benign lesion and this was a splenic hematoma another case type 2 endo leak now you need to read a little bit about endovascular ayatic repair and just an importance of contrast enhance ultrasound i wanted to show you that initial first and second image there was uh not relatively anything that could be suspicious of endo league but in a delayed image on 30 second delay there was a sag sweep that was done and behind the on the posterior aspect of the aneurysmal sac there was likely a leak from the lumbar artery so this is consistent with the type 2 endolete this is also one of the uses of contrast enhanced ultrasound potential use yes sentinel lymph node detection so there is a school of thought that says that ultrasound contrast injection can be done in a target organ and then we can see which lymph node is being drained by that organ by using the kuffer phase image of contrast enhanced ultrasound so these are still users that are still in decision making process and may come into use in near future so what is the evidence in future of contrast enhanced ultrasound how do we place it is it useful right so guidelines started developing in and 2003 may eurozone came then 2004 may the safety considerations limitations and all were published then in 2008 finally the monitoring of focal level lesions and after ablative treatment that came and applications of kidney and pancreas was being tested recent guidelines after definitely launchment and 2016 have now come that now non-hepatic applications are much involved in git spleen vuor scrotum lung and plural lesions breast kidney even in inflammatory joints but there is some place because uh criticism about the aasld guideline the american association for study of liver disease which has removed contrast enhanced ultrasound from its diagnostic flow algorithm because of some contrast agent characteristics but this these are all fluid situations all in all i think this is a very useful modality and it will definitely be very uh future diagnostic uh procedures helpful in program diagnostic procedures with and it will come up with broader applications as well so to summarize the presentation this contrast enhanced ultrasound is supposedly a novel modality but as we came to know from the presentation it has been present here from 1990s onwards it does have significant benefit over other techniques like comparison with ct and mr technical specification and criteria were lucidly discussed safety limitations and contraindications of contrast agents were discussed and then i showed you a series of cases in which liver kidneys clean all these how we were using contrast enhanced ultrasound to our advantage in such situation that was discussed and future applications are being discussed these are the all references that i have used for my uh this presentation and these articles in these journals are very lucid and very informative so you can bank on them for giving you the correct account of contrast enhanced ultrasound this is my book cornerstones of radiology and diagnostics basics and beyond it has ultrasound uh and doppler ctmr ct and x-rays and radiographic processing discussion uh tailored for resident and exam preparation in your free time you can also read my book did you survive 2020 which is based on the situation that we faced in 2020 and with this i end this presentation but i have a surprise for you right so with the vedita i have two videos which i have i'll show you which i have recorded in my department doing the contrast enhanced ultrasound on kidney lesions so let's start with video one this is the first reel that i'm sharing with you today so on the left side we have contrast enhanced specific mode and on the right side we have our regular grayscale mode so you can see that we are visualizing the kidney a patient the patient has multiple cysts in the kidney so this was a study that was uh being done to just note that how cysts are looking on contrast enhance ultrasound and also to see that any neoplastic features are present in the cyst or not so we have injected the agent the normal renal parenchyma as you can see it is becoming bright bright and brighter and however on gray scale there is hardly anything being appreciated and you see the uh the contrast enhanced ultrasound image is showing so much of contrast uptake in the normal general pattern time so this is the magic of contrast enhanced ultrasound slowly over the period of time just adjusting the window acoustic window yeah the system is again in view and now you can see the contrast material entering the pelvic lesial system so it has left the parenchyma and it is entering the pelvic lesion system but still the cystic lesions have not picked up anything the contrast agent is not being picked up by the cysts in the kidney so it is suggestive of a benign lesion benign simple cysts right you can see that this is the contrast agent has gone into the pcs and now it is no longer seen minimally visible now and with that only we end the first video right uh just flash the second video in this uh adjust a little this will keep flowing in the loop now with the background of the first video just try visualizing these two images the left one shows the contrast enhanced mode and the right one is the regular grayscale mode this patient we had this was a patient of tcc bladder who was given bcg chemotherapy and for two years he was asymptomatic responded very well to the treatment and two years later he started hematuria having hematuria and came to us for evaluation so we did a grayscale ultrasound image a grayscale ultrasound for him regular ultrasound and there was a suspicion of a [Music] hypoechoic lesion near the geneal pelvis yes right so now you can see the kidney has taken up contrast then two lesions near the renal pelvis one above and one below is showing loss of contrast is washing wash out complete wash out and very fast washer so yes i saw a few two three thumbs up and so i think you are guys picked up this lesion that is showing very fast quick wash out near the renal pelvis so this was a further uh this was a difficult uh case for us because now the patient actually is on the cards for rcc so metachronos tumors are known to occur and this was likely a case for one of them and this was recorded in our department and i thought of sharing this with you see here well defined two lesions are seen near the renal pelvis one above and one so these are the two cases with this my surprise is over and my lecture as well and i enjoyed presenting as much i hope that you enjoyed hearing it thank you so much thank you ma'am uh for this excellent presentation and a detailed session on the talk on contrast enhanced ultrasound and the cases k series that followed just a few questions from the attendees uh yes one is why is it that the first and the second generation uses low mechanical index the first generation uses high mechanical index because it has to rupture the micro bubbles to make them uh to make us see so the solar view that we are using is a second generation contrast agent so levovist is now not much involved only sono view is used or definitely in the places where it is available and these are the contrast agents which use a low mechanical index and at this uh using a low mechanical index the contrast agent is stable only when you turn the settings into a high mechanical index setting only then it will rupture otherwise it will stay stable and after a period of time the excretion will happen through the lungs there is no excretion through the kidneys or the liver right so i hope that explains your question yes ma'am and and one more uh can you please repeat uh regarding the linear and non-linear interaction linear interactions are linear oscillations when you increase the mechanical index from 0.3 to 0.5 linear oscillations initially will occur these occur because of within the sonic windows aft as you keep increasing the mechanical index then non-linear interactions will occur linear interactions happen generate signals because of the ultrasound contrast agent also and background tissue also so the generation of image is not very useful because of linear signals when we increase the mechanical index non-linear oscillations start and that is important because the low mi contrast agents the difference between non-linear signals between the contrast agent and tissue is much more so that the ultrasound image can be generated when you increase further the mi these contrast agents will burst the first generation also the second generation also both will burst so that's why we use low mi agent because in them the non-linear signals will help us to generate a different uh to generate ultrasound image because there is difference between the signals that are generated from contrast and the signals that are generated from tissue background tissue linear signals may there is not much difference and you can't pick that up to make a contrast your image that is the answer and one last one ma'am can you please explain regarding backscatter yes uh right so what happens is when we have ultrasound beam going through a tissue it ah there are as you you must have read about interactions between x-rays and matter similarly there is interaction between ultrasound and matter so the attenuation of ultrasound that happens is because of multiple reasons one is reflection because of which you are generating the normal ultrasound signals second is refraction when because when the ultrasound waves pass from one medium to the other third is friction frictional losses which convert into heat and fourth is back scatter or just scatter scatter happens when the ultrasound waves meet a object that is smaller than the wavelength of the ultrasound that is being generated so when the ultrasound waves meet that kind of object then scatter happens scatter as you similar to as you see in x-rays it causes fog so similarly here also it causes it is a negative thing but the contrast agents they increase the back scatter they amplify these negative signals which are bad bad bad domain signals they amplify these signals and bring it to our advantage these back scatter is increased because of contrast and ultrasound agent because they are very small 7 to 10 micrometer these act as scatter causing organisms causing agents so the ultrasound comes ultrasound waves come and they get scattered because of the contrast agent these small small microbubbles and this causes a generation of contrast enhanced ultrasound i hope that answers that question yeah thank you ma'am i think that's about uh i think that's about it man thank you so much ma'am and that was dr isha rajput lam associate professor department of radiology inhs ashwini mumbai for the excellent presentation and detail session thank you ma'am now i now i request the chairman of turf expansion team of kerala iria and president of ima pala branch to propose a vote of thanks over to you sir thank you and uh that was an excellent session of expansion program of uh kerala area and uh today we we are happy to have our great leader and great teacher dr valentin sir nasser for the opening remarks he's a great teacher and a great leader of kerala ira thank you sir for your efforts and time in strengthening our organization and budding radiologists and now about the presentation that was an excellent presentation from dr isha rajput thank you ma'am for the it was an in-depth and very extensive i haven't heard such an in-depth uh presentation on contrast enhanced ultrasound and you can it is she has covered almost all the uh even indications contraindications and the generations of contrast agents and the potential useful everything has been covered extensively that is a very a good presentation on the on the subject i haven't had such a beautiful presentation in this uh maybe maybe i haven't heard much but this is a there's an excellent presentation from your side thank you thank you once again from uh kerala iri and on behalf of the tough expansion program of kerala area and and i thank each and every uh participant of today's program for for attending this program and now not as always our doctor judy our master ceremony as always she has done a wonderful work in conducting such a beautiful program she has made us all comfortable and that was a wonderful evening from uh for us so thank you all the participants and i especially thank the netflix team for uh for their support uh and and on behalf of the ira kerala and tough expansion committee i thank each and everyone once again for the for participating in this program thank you thank you sir

BEING ATTENDED BY

Dr. Sasikanth Reddy & 194 others

SPEAKERS

dr. Eesha Rajput

Dr. Eesha Rajput

Associate Professor, Dept of Radiology, INHS Asvini, Mumbai

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dr. C. Kesavdas

Dr. C. Kesavdas

Consultant Neuroradiologist, Thiruvananthapuram

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dr. Judy Mary Kurian

Dr. Judy Mary Kurian

Professor Travancore Medical College, Kollam

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dr. Jose Kuruvilla

Dr. Jose Kuruvilla

Consultant Neuroradiologist, Thiruvananthapuram

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dr. Ramesh Shenoy

Dr. Ramesh Shenoy

Consultant Radiologist | Kochi

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dr. Rijo Mathew

Dr. Rijo Mathew

Consultant Radiologist | Kochi

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dr. M.C.J. Prakash

Dr. M.C.J. Prakash

Consultant Radiologist | President - IRIA, Kerala

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dr. Eesha Rajput

Dr. Eesha Rajput

Associate Professor, Dept of Radiology, INHS ...

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dr. C. Kesavdas

Dr. C. Kesavdas

Consultant Neuroradiologist, Thiruvananthapur...

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dr. Judy Mary Kurian

Dr. Judy Mary Kurian

Professor Travancore Medical College, Kollam

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dr. Jose Kuruvilla

Dr. Jose Kuruvilla

Consultant Neuroradiologist, Thiruvananthapur...

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dr. Ramesh Shenoy

Dr. Ramesh Shenoy

Consultant Radiologist | Kochi

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dr. Rijo Mathew

Dr. Rijo Mathew

Consultant Radiologist | Kochi

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dr. M.C.J. Prakash

Dr. M.C.J. Prakash

Consultant Radiologist | President - IRIA, Ke...

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