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learning courses across all key radiology sub specialties. Learn more at

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mrionline.com. Today we're honored to welcome Dr. Sikandar for a lecture

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on PET CT and abdominal pathologies. Dr. Sikandar is president of the ISMRM

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India chapter, Indian ambassador of the European Society of Hybrid, Molecular

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and Translational Imaging, and associate editor of the International Journal

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of MRI. At the end of the lecture, join Dr. Sikandar in a

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Q&A session where he will address questions you may have on today's topic.

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Dr. Sikandar, please take it from here. Thank you for a nice introduction,

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and I welcome all the attendees pan world. Good morning, good afternoon,

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and good evening to all of you. Now moving on. My topic today

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is PET CT in abdominal pathologies. But before that, I just want to

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give you a very short and brief overview of what exactly the molecular imaging.

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We know there are different presets and there are different components,

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different modalities which are involved in this molecular imaging. And the

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commonest ones are magnetic resonance that is MR, optical imaging, SPECT,

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PET probes and imaging of molecular interaction, nano imaging, stem cell

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imaging, genetic imaging, and optical imaging variants like you have bioluminescence,

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fluorescence and other things. Now coming to the molecular imaging, it is

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early 21st century, it is a discipline of intersection of molecular biology

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and in vivo imaging. So it is a visualization of the cellular functions,

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which is follow up of the molecular processes without disturbing them.

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So the diagnosis of diseases like cancer, neurological and cardiovascular

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pathologies can be easily diagnosed. And this is how the evolution of the

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molecular and functional imaging has given a new direction to the human

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genome. We all know the molecular imaging is also a part of traditional

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imaging, because a lot of probes which are known as biomarkers were used.

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And this image particularly targets all the various pathways which are involved

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in this molecular imaging. So what is the role of biomarkers? They interact

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chemically in their surroundings, they alter the image, they can do molecular

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changes. But most important within the areas of interest.

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So here, focusing the area of interest, the molecular imaging can be targeted

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and used as a diagnostic tool, and in future, used as a therapeutic tool.

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So that is where the diagnostics will be coming in picture.

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Now we all know the different modalities. Now coming to PET. Just very

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brief overview of PET. PET is a positron emission tomography and computed

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tomography. It is a combination of functional as well as anatomical imaging.

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And that's the reason it is known as metabolic imaging technique using the

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radio labeled analogs like glucose, as glucose is one of the important metabolic

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agent or the active agent which is being used by the normal tissues,

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and this is significantly increased in the malignancies. And coming to CT,

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we all know it is a tomographic imaging technique which uses an X ray beam

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to produce anatomical images. So this anatomical information is needed to

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detect, determine the location and extent of the malignancies.

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So it is a hybrid modality. It is a hybrid scanner with an

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integrated devices containing both CT as well as PET in a single patient

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table and capable of doing both CT or PET or both at a time. Usually, PET

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CT is used for the PET, but in some scenarios we can do

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CT individually. So that is also an individual application of PET individually,

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but PET usually is not being done now with the advent of the hybrid imaging.

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So it is a fusion of the process of aligning these both images

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leading to combined imaging displays, leading to various analysis. So this

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analysis is based on the combination of the images and displaying the images,

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and these fused images are displayed in various color coding that is

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available by different vendors. And CT, we all know it is being used

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by the grayscale. Now coming to the important aspect before going directly

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to the cases. So we have the scintillators. So what is the role of

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scintillators? They are the basic components, like we have detectors on

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the PET CT. So scintillators are comprised of the various components,

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like you have thallium, which are activated with sodium iodide, bismuth

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germanate, gadolinium oxyorthosilicate, and lutetium oxyorthosilicate that

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is light output. So among this, the most widely commonly used scintillator

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is lutetium oxyorthosilicate, that is LSO crystal, and these are having

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13 by 13 LSO block detectors. Now coming to the positron emitters.

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So what are the emitters actually? So these are positron emitters. You have

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radioisotopes and you have half life. So these are the emitters which are

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based on the radioactivity. So radioactivity means you have to have the

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radioisotope. What is a radioisotope? So it is a natural or artificial form

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of an element which is known as radioisotope. But here in PET, most

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of them, they are prepared artificially in a cycle.