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Medical Physics Resolved :) !!

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AsSalamalikum wr wb

will be sharing whole Medical keyPoints!
inReturn amples of Duas for success please :)

Bismillah!!
MRI:
In a nucleus Proton spins forming a tiny magnetic field,
when external magnetic field applies on it
some protons(specifically in NMR Hydrogen atoms) alligned within the field and some alligns against the field
The rotation of those protons are called precession and the angular frequency of precession is called larmour frequency,
This larmour Frequency lies in the range of RadioWaves
when Radio Waves are incident on them via Radiowaves transmitter the protons resonates and get excited and goes to higher energy level
after sometime they dexcites and release the energy
detectors of Radio waves detect those frequencies and measure the time called relaxation time
these relaxtion times helps to determine the organs
MRI Advantage:
dont uses any Ionic wave so not harmful like X-Rays
Mri gives better contrast of Soft tissues
can for 3d images via pc
Disadvantage
bones scanned are not as clear as CT scanned
steel nails or heartpacemaker inside body can get hot and melt

JazakAllah
others comming too
 
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Bismillah!!
Ultra Sound:
Ultrasound waves frequency lies above 20KHz
so 2Mhz will be sufficient to analyse for 1mm thick particle
Producing Ultrasound:
by Applying the PD across the transducer like(piezo electric crystal or quarts) these transducers vibrate which emits the soundwave whose frequency is like of Ultrasound waves
these same transducers are used to detect Ultrasound as they will be vibrated inducing emf,
When these waves are incident on the body (air-tissue) most of the are reflected
and detected!
so we use gel minimse the reflected intensity
in ultrasounds we are more intetrested in the reflected intensity and time taken by it rather than the incident intensities of waves
reflection depends on acoustic impedence Z
Z=density x speed
To calculate the intensities
(Ii/Ir) = ((Z2-Z1)/(Z2+Z1))^2
There are two types of Scans
A Scan:
in a scan a pulse of ultrasound wave is sent and times measured
thickness of bone=(speedx(timeTaken))/2
B-Scan
at every angle a dot is created creating a whole organ via computer
 
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