Improving contrast and tracking of tags in cardiac magnetic resonance images
| Autor: | M.A.M. Groot Koerkamp, A.M.M. Muijtjens, G.J. Kemerink, G. Snoep |
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| Rok vydání: | 1999 |
| Předmět: |
Computer science
business.industry Image quality media_common.quotation_subject Relaxation (iterative method) Image processing Tracking (particle physics) Intensity (physics) symbols.namesake Fourier analysis Histogram symbols Contrast (vision) Radiology Nuclear Medicine and imaging Computer vision Artificial intelligence business media_common |
| Zdroj: | Magnetic Resonance in Medicine. 41:973-982 |
| ISSN: | 1522-2594 0740-3194 |
| DOI: | 10.1002/(sici)1522-2594(199905)41:5<973::aid-mrm17>3.0.co;2-8 |
| Popis: | Cardiac tagging permits non-invasive study of myocardial motion with high accuracy. Unfortunately, tagging contrast is impaired at later heart phases due to longitudinal relaxation. Histogram modification is presented as a method for improving contrast in later, faded images of a tagging series by altering these images such that their intensity histograms approximate the shape of the first, unfaded image of the series. This technique greatly improves the contrast and facilitates automatic detection of tags. Furthermore, a method is described for automatically tracking tag positions in short-axis images of the left ventricle modulated with a tagging grid. The method differs from previously reported methods in that, in one single filtering process in the Fourier domain, both the grid crossings as well as the grid centers are detected, and thus increased sampling resolution is obtained. The method was validated by applying a mathematical model of left ventricular motion to tagged images of the thigh muscle. The average discrepancy between theoretically predicted and automatically detected tag positions was 0.04 +/- 0.17 mm (mean +/- SD). |
| Databáze: | OpenAIRE |
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