K-Space, Phase Encoding, and Frequency Encoding

These flashcards cover key vocabulary terms related to K-Space, Phase Encoding, and Frequency Encoding in MRI technology.

K-Space

An engineering term describing the raw data that will become the final MRI image; a collection of numbers or data points gathered during sampling.

Fourier Transform

A mathematical process that decomposes signals into their constituent frequencies; essential for processing signals in K-space.

Nyquist Theorem

States that data must be sampled at least twice per cycle to accurately represent a waveform, or else it risks under-sampling.

Phase Encoding

A method in MRI wherein different strengths of gradients are applied at various times to fill K-space rows with data.

Frequency Encoding

A method in MRI that assigns a range of frequencies to each pixel in the matrix based on the precessional frequency changes along a gradient.

Conjugate Symmetry

A property of K-space where the data is symmetrical on both sides and top and bottom halves, potentially allowing for reduced scan times.

Fast Fourier Transform (FFT)

An optimized mathematical algorithm used in MRI systems to efficiently convert data from Time Domain to Frequency Domain.

Partial Fourier

A technique used in K-space acquisition where only half of the data is sampled, potentially reducing scan times but risking amplification of errors in the final image.

Time Domain

A representation of the signal as it varies with time, which is transformed into the Frequency Domain via Fourier Transforms.

Amplitude

Refers to the strength of the signal being measured in K-space, affecting the overall quality and detail of the final MRI image.