Magnetic Resonance Imaging (MRI) Practice Test

What is the technique called for acquiring slightly more than half the phase k-space samples and then interpolating the data with zeros?

1. Half Fourier or zero fill

2. Full Fourier acquisition

3. Partial echo method

4. K-space sampling

The correct answer is: Half Fourier or zero fill

The technique of acquiring slightly more than half the phase k-space samples and then interpolating the remaining data with zeros is known as Half Fourier or zero fill. This method is used in MRI to reduce scan time while still capturing important information about the imaging object. In practice, this approach leverages the inherent properties of the Fourier transform, allowing for the reconstruction of an image even when only a portion of the k-space data is collected. By using zero filling for the missing data, the completed k-space can be transformed back into the image space, yielding an image that still retains useful diagnostic information despite the incomplete sampling. This technique is particularly beneficial for applications where time is a constraint, like in dynamic imaging scenarios or when dealing with patients who may have difficulty remaining still for extended periods. In contrast, Full Fourier acquisition entails gathering all of the necessary k-space data, which can result in longer scanning times. The Partial echo method may involve collecting only a segment of the echo data but does not specifically focus on half-space and zero filling. K-space sampling is a broader term that refers to the overall process of acquiring samples in k-space without implying the techniques of zero filling or interpolation.