 Okay. Good evening to everyone here. So I'll be presenting a paper on the atypical appearances of HCC, Hepaticella Contrast, Hepaticella Carcinoma on a Contrast Enhanced Multi Detector CT. So, I'm the author. My name is Dr. Mohanjeeke, my co-author is Dr. Shalinda Signorek and I'm presenting it from Mahanmata and the Medical College and Research Institute in Montenegro for CTBus. So, the first affiliations, a radio resident on this one and my disclosures, here are my disclosures. I have no conflicts of interest pertaining to the subject of this paper or the contents within. So, my abstract hepatocharsenogenesis is driven by the repeated development and expansion of progressively de-differentiated journal populations within the usually cirrhotic liver parangaima. So, these cells, when they grow, they become a HCC and the diagnosis is usually made by histopathology in the early days, but the diagnosis can be made without a biopsy if it appears as a typical mass lesion showing arterial non-rim hyper-enhancement and non-peripheral washout in the delayed phases as we see on our multi-physic CT scans. However, in cases with atypical features in which this typical pattern is not, it cannot be applied and thus it becomes important to know the different variants and their corresponding imaging features so that we can guide pre-operative biopsy and it is also important because it has a significant effect on prognosis as the atypical variants have a uniformly worse prognosis than our usual typical HCC with typical features. So, we are going to discuss three types of atypical HCC in this paper with imaging features, which we have discussed. So, introduction, HCC is the most common neoplasm in the origination cirrhotic liver usually with its prognosis largely depend by the stage of presentation and as I told you, it occurs due to repeated development and expansion of progressively de-differentiated journal populations within the liver parangaima along with progressive loss of the OATP expression or organic anion transporter expression which is a hallmark of normal hepatocytes. Due to this tumor neo-angiogenesis, most of the blood supply is got by the hepatic artery rather than the portal vein that supplies the rest of the majority of the liver. So, this difference allows lesion characteristics via multi-phasey computer tomography techniques which depict the typical lesion as HCC lesion as having arterial phase hyper-enhancement with washout in the daily cases. So, while this has obviated the need for biopsy in cases such as in Lyrax5 cases with typical imaging characteristics, atypical variants of HCC exist and their appearances are to be known as direct influences of prognosis as I told because many variants have a poorer prognosis and can also guide biopsies and stage so contrast enhancement protocols typically standardized in an institution include a late arterial phase approximately 30 to 40 seconds for maximum enhancement of like arterial phase, late arterial, portal venous phase approximately 70 to 100 seconds post-contrast and the delayed phase which usually takes 3 to 5 minutes post-contrast So, typical HCC shows homogenous arterial phase hyper-enhancement with washout compared to normal liver parenchyma on the delayed emitters. So, this is due to the neo-angiogenic properties inherent to the tumor with supply from the hepatic artery and the portal system. So, major variants of HCC which we will be seeing here are the diffused infiltrative type, the exophytic type and these sarcomatic HCC because these types can be confused with other tumors and due to misdiagnosis. So, coming to another case, this is a late arterial phase. This is a delayed phase in age of the HCC, axial HCC showing a well-defined lesion in the segments 8 of the liver of sarcomatic curved area with homogenous arterial phase hyper-enhancement and it's also showing washout in the delayed phase and here you can also see the hepatic artery which is like feeding to this region over here. So, then this is seen in the background of a cirrhotic liver with nodularity and portal systemic collector. So, this is a typical case of a typical HCC. So, the atypical variants diffuse infiltrative type for that the major differential is transient hepatic attenuation difference THAD will be coming to the imaging features later. The points of favor HCC are early washout, that is how normal area usually becomes isodense to deliver image at that. Mass effect will be present indeed usually good type of this one rather than this one. There will be enhancing thrombus in the vessels under presence of metastasis. Exophytic type is a can be confused with like Avanis amangema or a subcapsular lesion. Immortal points of differentiated from exophytic amangema include the artery phase hyper-enhancement with washout. There is amangema stupidity shown nodular perforation also the progress is filling in and the other one is the sarcomata CTC. The sarcomata CTC has high number of poor differentiated vessels and so on. They grow rapidly resulting in and outstrip their blood supply resulting in central necrosis by hemorrhage. So, differentiating it from a cholangia carcinoma is the main thing. So, usually by absence of intra-hepatic biliary radical dilation since that is hepatocellular cordon whereas cholangia carcinoma is of a biliary cell origin and subtle rim of hyper-enhancement may also be also be present in sarcomata CTC with variable washout. In contrast, cholangia carcinomas usually do not enhance much in the arterial phase and may show delayed enhancement in the delayed phases due to the prominent fibrous component to them. So, here are like three images. So, a late arterial phase, ocular venous and delayed phases showing an ill-defined hyper-enhancing lesion. This is showing non-uniform heterogeneous washout on the delayed images. So, this is non-uniform and heterogeneous washout. Here you can also see this wedge-shaped area of hyper-enhancing. Then this is due to the tumoral thrombus that is in the right portal. You can see a filling defect in the right portal which enhances similar to the ill-defined lesion in the right lobe of the liver. So, here the ill-defined thrombus also is like hypodense, enhances heterogeneous day and arterial phase and shows washout on these phases. So, on the third image also shows large necrotic nodal masses within the protecaval and ioticaval region. So, this diagnosis is the point is how diffuse infiltrative HSC with the tumoral thrombosis of the portal which may present as the first finding before you are able to see any other changes on our routine modalities. So, here is the other case. So, here is a exophytic lesion arising from the which is large and having a peripheral arterial phase hyper-enhancement related to the liver parenchyma over here and it is also showing washout on delayed phases compared to the liver parenchyma and there is a large centrally non-enhancing on necrotic area within. So, the differentiation from hemangerma is by because of the absence of the peripheral nodular enhancement in this case. The third case, the later reportability says is show a well-defined mass over here, a relatively like well-defined mass with a subtle group of arterial hyperenhancement. The rim is very subtle over here, hyperenhancement and this is showing washout on the delayed phases. Here you can see another stack of like imaging like hyperenhancement here, but the majority of the lesion itself is like or necrotic or non-enhancing suggesting necrosis. So, this was a prone case of sarcomatase HCC where it is predominantly necrotic, but the thin dermal peripheral hyperenhancement with washout has been seen. So, conclusion. While the typical HCC can be diagnosed with reasonable confidence on imaging, atypical areas can go to diagnostic dilemma due to their unfamiliarity and the resemblance with other lesions. So, since the imaging appearance can mimic other benign conditions and even other malignancies, a careful evaluation of the clinical and biochemical cases of it along with knowledge of the spectrum of imaging findings. Serum AFP levels can also be a useful adjunct and to label a tumor as epithelial nodule with a caveat that AFP negative HCCs also exist, as was described in the previous slide, AFP can be a useful adjunct. Knowledge of the imaging characteristics of these atypical variants along with characterization of liver, panacea, cirrhotic and non-cirrhotic, this is important because as majority of the HCCs are raised in a cirrhotic liver, can aid in the diagnosis and thus get targeted biopsies for patient care. And these are my references. Thank you.