q-Space imaging using small magnetic field gradient.
← Research streamThe authors propose a method to obtain moments of translational displacement and kurtosis from low q-value measurements, aiming to avoid the need for high q (high b) values in clinical MR. They report that mapping these quantities with ordinary clinical MR eq…
Study snapshot
Abstract
q-Space diffusion analysis is a method to obtain the probability density function of the translational displacement of diffusing water molecules. Several quantities can be extracted from the function that indicate a characteristic of the water diffusion in tissue, e.g., the mean displacement of the diffusion, probability for zero displacement, and kurtosis of the function. These quantities are expected to give information about the microstructure of tissues in addition to that obtained from the apparent diffusion coefficient (ADC); however, this method requires high q (i.e., high b) values, which are undesirable in practical applications of the method using clinical magnetic resonance (MR) imaging equipment. We propose a method to obtain certain quantities that indicate a characteristic of the diffusion and that uses low q-value measurements. The quantities we can obtain are the moments of translational displacement, R; the n-th order moment is defined as the average of Rn (n: integer). Kurtosis can also be calculated from the second and fourth moments. We tried to map the moments and kurtosis using clinical MR imaging equipment. We also estimated the inherent errors of the moments obtained. Our method requires precision in measuring spin echo signals and setting q values rather than using high q-value measurements. Although our results show that further error reductions are desired, our method is workable using ordinary clinical MR imaging equipment.
AI evidence extraction
Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.
Main findings
The authors propose a method to obtain moments of translational displacement and kurtosis from low q-value measurements, aiming to avoid the need for high q (high b) values in clinical MR. They report that mapping these quantities with ordinary clinical MR equipment is workable, though further error reduction is desired.
Outcomes measured
- q-space diffusion analysis quantities from low q-value measurements (moments of translational displacement, kurtosis)
- mapping moments and kurtosis using clinical MR imaging equipment
- estimated inherent errors of moments
Limitations
- Requires high precision in measuring spin echo signals and setting q values
- Further error reductions are desired
View raw extracted JSON
{
"study_type": "engineering",
"exposure": {
"band": null,
"source": "clinical magnetic resonance (MR) imaging equipment",
"frequency_mhz": null,
"sar_wkg": null,
"duration": null
},
"population": null,
"sample_size": null,
"outcomes": [
"q-space diffusion analysis quantities from low q-value measurements (moments of translational displacement, kurtosis)",
"mapping moments and kurtosis using clinical MR imaging equipment",
"estimated inherent errors of moments"
],
"main_findings": "The authors propose a method to obtain moments of translational displacement and kurtosis from low q-value measurements, aiming to avoid the need for high q (high b) values in clinical MR. They report that mapping these quantities with ordinary clinical MR equipment is workable, though further error reduction is desired.",
"effect_direction": "unclear",
"limitations": [
"Requires high precision in measuring spin echo signals and setting q values",
"Further error reductions are desired"
],
"evidence_strength": "insufficient",
"confidence": 0.74,
"peer_reviewed_likely": "yes",
"keywords": [
"q-space imaging",
"diffusion",
"low q-value",
"b value",
"spin echo",
"moments",
"kurtosis",
"clinical MRI"
],
"suggested_hubs": []
}AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.
Identifiers and source
DOI: 10.2463/mrms.5.179
PubMed: 17332708
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