Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Minimization of errors in biexponential T 2 measurements of the prostate
Ist Teil von
Journal of magnetic resonance imaging, 2015-10, Vol.42 (4), p.1072-1077
Erscheinungsjahr
2015
Quelle
Wiley Online Library
Beschreibungen/Notizen
Purpose
To determine the echo times that provide the greatest precision in measurements of prostate
T
2
s.
T
2
relaxation time measurements in the prostate are complicated by the structure of prostate tissue, which consists of fluid‐filled glands surrounded by epithelial and stromal cells. Since the glands are large relative to diffusion distances, there is little water exchange between the two compartments and
T
2
s are biexponential. Because the relative size and characteristics of the two compartments change in prostate tumors, accurate measurement of the characteristics of each may provide useful information on tumor grade.
Materials and Methods
T
2
s were measured in a group of 25 men with biopsy‐proven prostate cancer. Subjects were scanned at 3T with a 16‐echo turbo‐spin echo
T
2
‐mapping sequence. Normal prostate
T
2
s were measured in areas showing no disease. Optimum echo times for measurement of normal prostate
T
2
s were found by calculating the covariance matrix, which provides estimates of parameter variance. Echo times that minimize
T
2
variance were then found by searching over grids of different echo times. Optima for four to eight echo acquisitions were found. Optima were tested by Monte Carlo simulation.
Results
Fast and slow
T
2
s were 60 msec and 360 msec, respectively. The fast signal fraction was 0.6. Optimum echo times were between 0 and 780 msec, depending on the number of echoes acquired.
Conclusion
Use of optimum echo times can substantially improve the precision of biexponential
T
2
measurements. This optimization is anticipated to improve prostate cancer characterization using
T
2
measurements. J. Magn. Reson. Imaging 2015;42:1072–1077.
Sprache
Englisch
Identifikatoren
ISSN: 1053-1807
eISSN: 1522-2586
DOI: 10.1002/jmri.24870
Titel-ID: cdi_crossref_primary_10_1002_jmri_24870
Format
–
Weiterführende Literatur
Empfehlungen zum selben Thema automatisch vorgeschlagen von bX