Related Experiment Video
Updated: May 6, 2026

09:55
Author Spotlight: Using Hyperpolarized Xenon-129 MRI to Study Lung Diseases
Published on: January 5, 2024
1.9K
An aliasing artifacts reducing approach with random undersampling for spatiotemporally encoded single-shot MRI
Lin Chen1, Lijun Bao1, Jing Li1
1Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China.
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|November 5, 2013
Summary
Spatiotemporally encoded (SPEN) MRI offers improved field inhomogeneity resistance. A novel hybrid reconstruction using random sampling, SVD, and CS effectively reduces aliasing artifacts in SPEN imaging.
Area of Science:
- Magnetic Resonance Imaging (MRI)
- Image Reconstruction
- Medical Physics
Background:
- Echo planar imaging (EPI) is susceptible to field inhomogeneity.
- Spatiotemporally encoded (SPEN) MRI offers enhanced field inhomogeneity immunity.
- SPEN MRI requires effective reconstruction methods to address undersampling artifacts.
Purpose of the Study:
- To develop and evaluate a hybrid reconstruction scheme for SPEN MRI.
- To reduce aliasing artifacts caused by vast undersampling in SPEN images.
- To improve the overall image quality of SPEN MRI.
Main Methods:
- A hybrid scheme combining random sampling, singular value decomposition (SVD), and compressed sensing (CS).
- Implementation of super-resolved reconstruction for SPEN imaging.
- Validation through numerical simulations, water phantom experiments, and in vivo rat brain imaging.
Main Results:
- The hybrid scheme significantly reduced aliasing artifacts in reconstructed SPEN images.
- Comparable spatial and temporal resolutions were maintained post-reconstruction.
- Demonstrated efficiency in reducing artifacts under vast undersampling conditions.
Conclusions:
- The proposed hybrid reconstruction scheme is effective for SPEN MRI, especially in undersampled scenarios.
- This method enhances the practical applicability of SPEN MRI by improving image quality.
- The technique offers a valuable solution for mitigating artifacts in advanced MRI sequences.
Related Concept Videos
Aliasing
948
Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency.
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original...
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original...
948
Upsampling
749
Managing signal sampling rates is essential in digital signal processing to maintain signal integrity. A decimated signal, characterized by a reduced frequency range due to its lower sampling rate, can be upsampled by inserting zeros between each sample. This upsampling process expands the original spectrum and introduces repeated spectral replicas at intervals dictated by the new Nyquist frequency. To refine this zero-inserted sequence, it is passed through a lowpass filter with a cutoff...
749
Downsampling
874
When considering a sampled sequence with zero values between sampling instants, one can replace it by taking every N-th value of the sequence. At these integer multiples of N, the original and sampled sequences coincide. This process, known as decimation, involves extracting every N-th sample from a sequence, thereby creating a more efficient sequence.
The Fourier transform of the decimated sequence reveals a combination of scaled and shifted versions of the original spectrum. This...
The Fourier transform of the decimated sequence reveals a combination of scaled and shifted versions of the original spectrum. This...
874
Bandpass Sampling
682
In signal processing, bandpass sampling is an effective technique for sampling signals that have most of their energy concentrated within a narrow frequency band. This type of signal is known as a bandpass signal. The key principle of bandpass sampling involves sampling the signal at a rate that is greater than twice the signal's bandwidth to prevent aliasing.
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....
682
Sampling Theorem
1.7K
In signal processing, the analysis of continuous-time signals, denoted as x(t), often involves sampling techniques to convert these signals into discrete-time signals. This process is essential for digital representation and manipulation. A critical component in sampling is the train of impulses, characterized by the sampling interval and the sampling frequency. The relationship between these parameters and the original signal's properties dictates the success of the sampling process.
1.7K

