Monday, August 26, 2019

Discuss the diagnostic value of CT and MR imaging in the diagnosis of Essay

Discuss the diagnostic value of CT and MR imaging in the diagnosis of hepatocellular - Essay Example The environmental factors are also found to have a greater influence on HCC. The higher level of consumption of alcohol also causes HCC. (Carr 2009). The recent advances in the tissue specific image analysis have made the diagnosis of the diseases at the inner organs very easy with high sensitivity. MRI and CT are the two techniques that use the image analysis. HCC is a very chronic liver disease with several levels. Hence the diagnostic of each level is very essential for the complete treatment and also for resection of the part. (Kamel and Bluemke 2002). Any destruction to the liver parenchyma, biliary ducts and vascular structures must be analyzed properly to study the liver dysfunction. HCC can occur as an infectious or inflammatory disease resulting in storage and metabolic disorders and sometimes may lead to vascular diseases or neoplastic disease. Diagnosis of HCC: When a person is suspected with HCC, the ultra sound diagnosis is done first and if the case is found to be much severe then contrast medium – enhanced helical computed tomography (CT) along with dynamic magnetic resonance (MR) imaging is used. Combination of CT and MR is found to give accurate non-invasive screening modalities. At the time of diagnosis, the tumor may be small or large. The infection level may be small or chronic. The diagnosis must be able to provide complete information regarding the condition of the tumor and the level of treating it. For this we require a proper diagnostic technique. The studies have found that MRI or CT can provide better diagnostic results. But it was also found that MRI can predict results only to certain limit and so do CT. So a further analysis of these techniques will provide a good idea of what to use and when to use. As HCC are hyper vascular disease, contrast agent is used for the diagnosis. There are four phases in the liver CT scanning. They are pre contrast, arterial phase, portal venous phase and delayed phase. The CT scan is performed for these phases based on the disease condition whether it is hyper vascular or hypo vascular. In CT scan, the pre contrast phase imaging helps us to detect the calcifications in the liver and they are also able to demonstrate the hyper vascular lesions present hypo attenuating to the parenchyma liver cells. (Hayashida et al. 2007). The arterial phase imaging is done after 30 seconds from the injection of contrast phase. The arterial phase scanning is used to demonstrate the hyper vascular lesions that are present in the liver by the enhancement of the liver. This arterial phase imaging helps the doctors to decide whether to go for operation of the tumor or treat it with medicines. This imaging is done as a 3D imaging and thus is of more useful in diagnosis. The portal venous phase is done after 70-90 seconds of injecting the contrast medium and they help to evaluate the hypovascular lesions in the body. (Kamel and Bluemke 2002). The last phase is the delayed phase where the lesions are characterized further after 5 – 10 minutes of injection. The HCC can be seen as hypodense lesions as the contrast pahse is washed out completely. Pathologic changes in the hepatic cirrhosis: Cirrhosis occurs due to the hepatic injury and results in the fibrosis diffusion. The nodules are regenerated from the liver cell necrosis and

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