Brain Imaging Crash Course ️

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hello and welcome to our last presentation  today we talking about neuroimaging okay   fast reviews of our  goals and objectives for this lecture you always have to know the anatomy very well  you know anatomy you cannot learn radiology   uh you have to know what this mri is more  appropriate or for spine imaging or why the   CT scan is more appropriate for emergencies  you have to discriminate between different   pathologies for the brain, we're  talking about emergencies mainly and you have to construct the appropriate  imaging approach of common diagnosis okay for start let's go to talk about what  is a neuroimaging an umbrella term encompassing a variety of methods  and technologies okay it was divided into main   areas: structural imaging and functional imaging   so today we have we focus about extruder imaging  okay that the tutorial imaging provides image of   the brain anatomy structure. this type of imaging  helps in the diagnosis of brain injury and the   diagnosis of certain diseases okay in this case we  use a CT scan and MRI remember just   we want to look at the functional imaging    Functional imaging provides images of the brain image as patients complete tasks such as solving   math problems or reading or responding to  stimuli such as auditory sounds or   flashing lights. examples of these ones  are positron emission tomography    regional cerebral blood flow, and functional magnetic resonance imaging this is a sample of functional structure so in this case this is in 3D with a lot of colors  there we can find thIS kind of studies in   big institutions and research  institutions in a few countries so let's be focused on our issue today,  structural imaging so let's go to talk about   computer tomography and MRI, so uh Computer Tomography uses a lot of radiation   okay remember, MRI doesn't use radiation, for that reason, it's very safe for   obstetric patient but what happened is, the computer tomography can be very fast, you can scan   a patient I think the head of the patient is less  than one minute for any type of study of MRI should  be between 20 to 25 minutes MRI is very very good for soft tissues.  It going to  give you more details for soft tissues and the  spine CT Scan because it's faster is very good for  emergencies, because it's faster is very good   for emergencies, for any head trauma, we don't request  MRI, we request a ct scan okay because it's   very fast, you cannot put a patient with  head trauma for 25 -30 minutes inside of the MRI   machine, they can die over there but for ct scan  remember sometime in less than one minute okay so remember ct scan findings i will  described densities and MRI intensities   densities and MRI intensities okay now let's go and be focus in emergencies, are the   things you are going to be seeing more during  your career unless you become radiologists okay   so let's go to talk about ct scans. these are relative densities, remember    our first lecture, the bones has a high  density and the air a low density so the air  is hypodense, everything with a gray soft  tissue and great it should be isodense   and the brightness is high density is hyperdense, now how to describe a head CT scan  you have always to start with this sentence.  this is a non-contrast or contrast enhanced   maybe axial, sagittal, or coronal head CT scan showing. you always have to start with  

this one, we have a simple ct scan which is  a non-contrast and contrast CT scan we can use   both so for a contrast CT can we use the  iodine compounds which   are positive you remember that so this is an example of normal CT scan from top to bottom of course you have to look at  it and you have to go for the   anatomy, remember we talked about anatomy in our first lecture,   I think, you have to go and look at the anatomy  normal axial head CT scan. you have to go and deep on that, also you have to look at the   distribution of artery's territory. is a distribution of the anterior cerebral artery   middle artery and posterior cerebral artery. you have to look at it very deep now   let's go to talk about lesions, for defined lesions you have to know the relationships and location within the brain tissue.  intraparenchymal is located within brain tissue.  the extraparenchymal is located within the bony casing of the central nervous system  but outside the brain tissue itself all right so let's go to find out these locations and we are going to start with extra parenchymal  locations, you can see it here we have this   two examples of Meningiomas, okay which are benign tumors, these are extra parenchyma   location the tumor this kind of tumors is  slow growing but you can see is reflecting   a mild displacement of the other brain  structures, and you see is growing from outside of your brain tissue there are a   few characteristics of differences more between the  intra and extra parenchymal brain location   now this is an example of intraparenchymal lesions   we had the example of Neuroblastoma, you see they are in the middle of the brain.

remember you have to look at it, what  if the difference between intra and  extra parenchymal locations, okay inside of brain pathologies. Now Head CT in acute situations.  anytime someone has head trauma, they should have head   ct scan or repeat again, anytime someone has  head trauma you have to request for ct scan in this case, you are looking for acute blood, which is bright or hyperdense or so all medical doctors should know what acute blood looks like and be able to describe it   and it is general location, there are five general locations for acute blood we have Epidural, Subdural, Subarachnoid, Intraventricular, intraparenchymal These are the anatomic specification for what i explained to you   and these are examples of bleeding okay in the first one you have an extradural hematoma in the other, we have the middle shift we got   intraparenchymal hematoma which is inside of the brain then we have a subdural hematoma which is very very dangerous  the patient can die from a subdural hematoma and subarachnoid hemorrhage. you can see the locations. now let's go to be specific about  this one subdural hematoma, you see there is a left subdural hematoma which is shifting the brain to the right producing mass effect     you can see there the left lateral ventricle  is compressed because of this hemorrhage and   is shifting the line to the other side they  will call it mass effect, mass effect.

you have to know very well the  difference between extradural hematoma and subdural hematoma  know very well you have to go deep and know the difference between extradural and subdural these are other examples of multiple locations  of this kind of hemorrhage, these are   contusion hematomas,  you can see all these extradural haematomas, some intraparenchymal after trauma The management of the patient depends on the Glasgow of the patient and also   depends of the amount of blood, the management of the patient depends on the   Neurosurgeon, quantity, position and the Glasgow of the patient so this is another example of being different location you have an intraventricular hemorrhage   this is another example of  bleeding, we have a subarachnoid hemorrhage remember you have to read everything  what i put in the slides on this video to   stop the video and read everything if i told you  go deep in this area you have to go deep okay   you have to review later to be like your  homework now how to assess a CT of the head  before you call a Neurosurgeon, you have to ask   yourself, these six main questions, these are the questions I do myself every day to read a CT scan   the First question is if the brain is in the middle of the head?  do the 2 sides of your brain look alike? is the fourth ventricle in the midline and symmetrical?  Are the lateral ventricles huge with effaced sulci? Are there any abnormal white things inside   the skull? or are they any abnormal black things inside the skull? remember white things    hyperdense and black  things are hypodense, so if there is any abnormal   hyperdense thing inside the skull? or there is any abnormal hypodense inside the skull? okay so first question is the brain in the middle of the head? you can compare the left side  which is normal with the right side, you can see the brain is not in the middle of the head. do the two sides of the brain look-alike? you can see, in the left side, both sides look-alike  but in your right, it doesn't look alike if the fourth ventricle in the midline and symmetrical? you can see in your   left , the four ventricle in the middle line and symmetrical and hypodense. in the   midline of the posterior fossa, but you can see in the second image, is not in the middle line   and there is no hypodense, there is hemorrhage, and then the other is a tumor ,there is a tumor so talk about the ventricles you can see two  different 30 years old patient in the left is   a normal ventricle size   in the right side there is a ventriculomegaly   The wideness of the ventricle is up 1,0 centimeter in young patients   after 60 years up to 1.5 centimeter  it's up to 1.5 centimeters so  

anything above or that it considers ventriculomegaly okay you have to pay attention to that let's look at this example this is a 68 yrs old female brought in by ambulance after rapid mental status deterioration we consider the hypertensive hemorrhage, in this case, there is no trauma okay and   the head CT scan shows, you can see. the patient has a history of high blood pressure and you can see this intraparenchymal hemorrhage or hematoma huge hematoma you have this hyperdense area surrounded by hypodense   area which is edema with the shifting of the middle line to   the right side to the right side okay  that means there is a huge mass effect this is the final diagnosis. the left side edema and significant midline shift or mass effect we look at this hypodense thing inside of the brain  remember, are there any abnormal black things inside of the brain?  when we talk about hypodense things inside of the brain, we talk about stroke we have to think   first about the stroke, ischemic stroke in this case, stroke can be hemorrhage like we saw before   and ischemic, hemorrhage is vessel rupture and ischemic is vessel obstruction. okay an infarction so this patient developed a headache, completely loss of consciousness and vomiting okay you can see there is a large area of hypodense or low density in the right cerebral hemisphere which   represents a right middle cerebral artery infarct.  so you have to remember to look at    the territory of the arteries.

and this is another example of infarction or stroke, ischemin stroke, there's another   example here you can see this hypodense area on  both sides one in your left which is in the   right, but you can see this one    in your left in which the hypodense is in the right you can see   the hypodense is huge and there is no  shift of the midline and also there is   the right lateral ventricle is not compressed. you compare with the left side   the lateral ventricle is dilated is deleted  because we are in the presence of chronic   ischemic stroke or cerebral infarct, that for you   you have to go and go deep in what is an acute, subacute, and chronic cerebral infarct  so these are examples of kind of  edema but in this case we're in the presence   of tumor you can see in your left this is a  non-contrasted ct scan which just appeared this vasogenic edema but after that we saw  we think okay this is   look like a stroke but this edema look more like a tumor so we put a contrast inside the patient   and you can see this hyperdense  ring inside of this hypodense area   area, we are in the presence of a tumor, so let's move on. these are examples of other tumors, for your general knowledge but  for us I think this is all for today remember   you have a few homework to do also reporting more  videos so you can understand better because this   this is trauma an emergency   is key for you is the one that you were  to watching almost every day so see you

2021-09-23

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