Table of Contents
What is presaturation in NMR?
Presaturation[1] is a technique of solvent signal suppression, where a long low-power pulse is applied on the solvent resonance before the pulse sequence.
What is a pulse in NMR?
In Fourier transform NMR spectroscopy and imaging, a pulse sequence describes a series of radio frequency pulses applied to the sample, such that the free induction decay is related to the characteristic frequencies of the desired signals.
What is a 90 degree pulse NMR?
The 90º pulse-width (pw90) is the length of a pulse, usually in microseconds, that will produce the maximum response from a given NMR-active nucleus. The value of pw90 depends on the nucleus, pulse power (tpwr), probe tuning, and the research sample.
What is a π pulse?
Perfusion Index or PI is the ratio of the pulsatile blood flow to the non-pulsatile static blood flow in a patient’s peripheral tissue, such as finger tip, toe, or ear lobe. Perfusion index is an indication of the pulse strength at the sensor site. Perfusion index is normally monitored with pulse oximeters.
What is the purpose of presaturation in NMR?
From NMR Wiki. Presaturation[1] is a technique of solvent signal suppression, where a long low-power pulse is applied on the solvent resonance before the pulse sequence.
How does presaturation work in a water suppression experiment?
Water Suppression using Presaturation (presat) Presat is a simple two-pulse experiment that utilizes a relatively long, low power RF pulse to selectively saturate a specific frequency, typically water, and a non-selective 45- 90º pulse to excite the desired resonances.
How are spectral saturation pulses used in MRI?
Spectral Saturation Pulses suppress a particular chemical species, usually fat, based on its chemical shift. Also known as Fat-Sat or Chemical Shift Selective (CHESS), these are short-duration RF-pulses tuned to the resonance frequency of fat and applied immediately before the start of an MR imaging sequence.
What is the purpose of spatial presaturation in MRI?
Spatial presaturation: a method for suppressing flow artifacts and improving depiction of vascular anatomy in MR imaging. Radiology 1987;164:559 –564.