Section PD weighted imaging 19 Jul 202218 Jul 2022 Manipulating TR and TE helps us to weight the contrast of the image to a certain parameter while diminishing the impact of other parametersIn PD weighting, the intrinsic contrast of…
Section T2 weighting 18 Jul 202217 Jul 2022 Manipulating TR and TE helps us to weight the contrast of the image to a certain parameter while diminishing the impact of other parametersIn T2 weighting, the T2 relaxation time…
Section T1 weighted imaging 17 Jul 202217 Jul 2022 Manipulating TR and TE helps us to weight the contrast of the image to a certain parameter while diminishing the impact of other parametersIn T1 weighting, the T1 relaxation time…
Section T2 decay 17 Jul 202217 Jul 2022 Decay of NMV in the transverse plane in an exponential mannerOccurs due to spin-spin interactionsThe intrinsic magnetic fields of nuclei causes loss of coherence, resulting in dephasingIt is intrinsic to…
Section T1 recovery 12 Jul 202212 Jul 2022 Also known as spin lattice energy transferIt is the time taken to for the spins to dissipate energy so that they regain their longitudinal magnetizationIt is an exponential processIt is…
Section Pulse sequence 12 Jul 202212 Jul 2022 Series of RF pulses, gradients and intervening time periodsTime period determines image weightingSequence is needed to produce signals sufficient enough to form an imageChanging TE and TR enables forming different…
Section T1 recovery and T2 decay 12 Jul 202212 Jul 2022 T1 recovery Once RF is applied, spins move to high energy states. Once RF is removed, they transfer this energy to the lattice, called the spin lattice energy transfer.Slowly the…
Section Free induction decay and T2* decay 12 Jul 202212 Jul 2022 Free induction decay Apply an RF pulse, achieve desired resonance and flip angle, then RF pulse is removedSignal induced in receiver coil begins to decrease in amplitudeThis signal decrease is…
Section Brownian motion, behavior of fat and water in mri 11 Jul 202211 Jul 2022 Brownian motion Each substance contains molecules that are constantly in motionThis motion has rotational and transitional componentsThe faster the motion within, the harder it is to release energy to its…
Section TR, TE and flip angle 11 Jul 202211 Jul 2022 Repetition time (TR) Time between one RF pulse to the nextMeasured in milliseconds (ms) Time to echo (TE) Time between RF excitation pulse and collection of signalMeasured in milliseconds (ms)…
Section Signal intensity in MRI 11 Jul 202211 Jul 2022 Depends on the magnitude of coherent transverse magnetizationLarger the transverse magnetization, higher the signal intensity
Section Contrast-to-noise ratio (cnr) 11 Jul 202211 Jul 2022 Difference in signal between two adjacent areasLarger the difference, better the CNR