k-space
Last revised by Candace Makeda Moore
on 16 Sep 2024
Citation, DOI, disclosures and article data
Citation:
Bashir U, Moore C, McKay L, et al. k-space. Reference article, Radiopaedia.org (Accessed on 06 Dec 2024) https://doi.org/10.53347/rID-18820
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rID:
18820
Article created:
23 Jul 2012,
Usman Bashir
Disclosures:
At the time the article was created Usman Bashir had no recorded disclosures.
View Usman Bashir's current disclosures
Last revised:
16 Sep 2024,
Candace Makeda Moore
Disclosures:
At the time the article was last revised Candace Makeda Moore had no financial relationships to ineligible companies to disclose.
View Candace Makeda Moore's current disclosures
Revisions:
8 times, by
7 contributors -
see full revision history and disclosures
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Synonyms:
- K Space
k-space is an abstract concept in mathematics but in terms of MRI physics refers to a data matrix containing the raw MRI data. This data is subjected to mathematical function called a transform to generate the final image. A discrete Fourier or fast Fourier transform 1-3 is generally used, though other transforms such as the Hartley 4 can also work.
Discussion
Each point on the k-space contains specific frequency, phase (x,y coordinates) and signal intensity information (brightness). Inverse Fourier Transform is applied after k-space acquisition to derive the final image. Each pixel in the resultant image is the weighted sum of all the individual points in the k-space. Hence, disruption of any point in the k-space translates into some form of final image distortion, determined by the frequency- and phase-related data stored in that particular point. In general:
central regions of the k-space encode contrast information (higher signal amplitude and lower resolution)
peripheral regions of the k-space encode spatial resolution (lower signal amplitude and higher resolution)
Relevance
Knowledge of the k-space is essential as it relates to different techniques of image acquisition and explains several MRI artifacts.
Quiz questions
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References
- 1. Zhuo J, Gullapalli RP. AAPM/RSNA physics tutorial for residents: MR artifacts, safety, and quality control. Radiographics. 26 (1): 275-97. doi:10.1148/rg.261055134 - Pubmed citation
- 2. Stark DD, Bradley WG, Bradley WG. Magnetic resonance imaging. C.V. Mosby. (1999) ISBN:0815185189. Read it at Google Books - Find it at Amazon But, in order to make it look like that, you'll need to copy the HTML code below. Stark DD, Bradley WG, Bradley WG. Magnetic resonance imaging. C.V. Mosby. (1999) ISBN:0815185189. Read it at Google Books - Find it at Amazon
- 3. F. W. Wehrli. Fast Scan Magnetic Resonance. (1991)
- 4. Bracewell RN. The Fourier transform. Sci. Am. 1989;260 (6): 86-9, 92-5. Pubmed citation
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