Week 1 Video part 2 of Concepts of cross sectional anatomy Flashcards
MRI (Magnetic Resonance Imaging)
Pull on Hydrogen atom alignment and relalignment
MRI
Magnetic Resonance Imaging (MRI) uses a strong magnetic field and radio waves to create detailed images of the inside of the body:
1. Align protons
The patient lies on a flat bed and is moved into the MRI scanner, either head first or feet first, depending on the body part being scanned. The scanner’s powerful magnet creates a strong magnetic field that forces protons in the body to align with it.
2. Stimulate protons
A radiofrequency current is then pulsed through the patient, stimulating the protons and causing them to spin out of equilibrium.
3. Detect energy
MRI sensors detect the energy released as the protons realign with the magnetic field.
4. Create images
The scanner uses this information, along with a computer, to create a detailed cross-sectional image for the radiologist.
MRI
MRIs can show organs, bones, muscles, and blood vessels. Different tissues appear in different shades of gray, from black to white, depending on the amount of fat and water they contain, as well as the machine settings used.
MRI Image
Uses gray scale and same method of a voxel. Also displays coronal, axial and sagittal. Body is made up mainly of water hence H2. There are carbon chains in bones which have hydrogen
MRI precession
MRI
The precessional path around the magnetic field is circular like a spinning top. The Larmor or precessional frequency in MRI refers to the rate of precession of the magnetic moment of the proton around the external magnetic field. The frequency of precession is related to the strength of the magnetic field,
MRI magnet unit
Tesla, radio frequencies.
MRI images
The way that the energy is collected allows for an image in coronal, sagittal, and axial. of course can then create oblique. CT does reconstruction from volume to produce image which MRI does not.
MRI contrast gadolinium
Gadolinium-based contrast agents (GBCAs) are often used in MRI scans to improve the clarity of images and help with diagnosis. GBCAs are clear, colorless fluids that contain gadolinium, a silvery-white metal with magnetic properties. During the scan, gadolinium reacts with nearby water molecules in the body, altering their magnetic properties and enhancing the quality of the images.
It is toxic to the body but is coated so that it does not impact the body.
MRI image of machine
Bore, hydrolic table, there are open MRI’s.
MRI Sequencers T1 and T2 to change the grey value assigned to the tissue
T1/T2 is the length of time introducing the frequences
T1- soft tissue, muscles
T2- Fluid, exp synovial fluid in joint
MRI coils
Allows focus of MRI signal. to improve signal
Functional MRI brain activity
MRI vascular image
can use contrast to help with imaging
Ultra Sound
Uses a gray scale, uses a transducer that has crystals imbedded in the head, creates and collects signal. Soundwaves create signal, uses gel to improve signal strength, sound waves reflect off of structure that creates the echo. the way the wand is angled provides the plane. Can do color adjustments.
Ultra Sound transducers
superficial-skin surface, endocavity- (rectume, vaginal), endoscopic (stomach, uretra), endovascular (heart)
Ultra Sound 3D
can do 3D. image on right is the 3D model and the left is an actual picture.
Nuclear Medicine
Uses gray scale. Introduces a pharmaceuticals radio-isotope, inhale or swallow.
AI- Radiopharmaceuticals are drugs that contain radioactive isotopes, also known as radionuclides, and are used in nuclear medicine to diagnose and treat medical conditions. Radioisotopes are unstable chemical elements that release radiation as they break down and become more stable.
Nuclear Medicine Machine
Assess monitor for patient vitals. Gamma camera to detect gamma radiation.
Nuclear Medicine Bone Scan
once radio-isotope is taken it can take up to 4 hours until imaging of bones.
Nuclear Medicine Brain function
brian function can look for L/R side, stroke, tramatic injury, Some kind of drowning low O2.
PET activity level chart
Brain image, blue low and red high activity
Positron Emission Tomography (PET)
Looking for where glucose is being used with the body. Looking for very active area. Where excessive glucose consumption.
AI- Positron Emission Tomography (PET) scans use a small amount of radioactive glucose (sugar) to create images of the body that show where glucose is being used. The glucose is attached to a radioactive atom to create a radionuclide called fluorodeoxyglucose (FDG). The scanner then rotates around the body to take pictures of the areas where the glucose is being used
PET scan brain comparison with alz
PET functional activity
showing area of the brain where there is high activity. High area’s of glucose activity
Imaging Identification
