k-space interpretation of the Rose Model: noise limitation on the detectable resolution in MRI.

Titlek-space interpretation of the Rose Model: noise limitation on the detectable resolution in MRI.
Publication TypeJournal Article
Year of Publication2002
AuthorsWatts R, Wang Y
JournalMagn Reson Med
Volume48
Issue3
Pagination550-4
Date Published2002 Sep
ISSN0740-3194
KeywordsMagnetic Resonance Imaging, Models, Theoretical, Phantoms, Imaging
Abstract

Noise limitation on the detected spatial resolution, described by the Rose Model, is well known in X-ray imaging and routinely used in designing X-ray imaging protocols. The purpose of this article is to revisit the Rose Model in the context of MRI where image data are acquired in the spatial frequency domain. A k-space signal-to-noise ratio (kSNR) is introduced to measure the relative signal and noise powers in a circular annulus in k-space. It is found that the kSNR diminishes rapidly with k-space radius. The Rose criterion that the voxel SNR approximately 4 is translated to kSNR cutoff values was tested using theoretical derivation and experimental histogram analysis. Experiments demonstrate that data acquisition beyond this cutoff k-space radius adds little or no information to the image. In order to reduce the noise limit on spatial resolution, the signal strength must be improved through means such as increasing the coil sensitivity, contrast enhancement, and signal averaging. This finding implies that the optimal k-space volume to be sampled or the optimal scan time in MRI should be matched to the relative SNR level.

DOI10.1002/mrm.10220
Alternate JournalMagn Reson Med
PubMed ID12210924
Grant ListHL62994 / HL / NHLBI NIH HHS / United States
R01 HL60879 / HL / NHLBI NIH HHS / United States
Related Institute: 
MRI Research Institute (MRIRI)

Weill Cornell Medicine
Department of Radiology
525 East 68th Street New York, NY 10065