A Simplified Model for Intravoxel Incoherent Motion Perfusion Imaging of the Brain.
- Conklin J From the Department of Medical Imaging (J.C., C.H.), Sunnybrook Health Sciences Centre and University of Toronto, Toronto, Ontario, Canada.
- Heyn C From the Department of Medical Imaging (J.C., C.H.), Sunnybrook Health Sciences Centre and University of Toronto, Toronto, Ontario, Canada.
- Roux M Department of Diagnostic and Interventional Radiology (M.R., M.C., C.F.), Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
- Cerny M Department of Diagnostic and Interventional Radiology (M.R., M.C., C.F.), Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
- Wintermark M Department of Radiology (M.W.), University of Virginia, Charlottesville, Virginia.
- Federau C Department of Diagnostic and Interventional Radiology (M.R., M.C., C.F.), Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland christian.federau@gmail.com.
- 2016-08-27
Published in:
- AJNR. American journal of neuroradiology. - 2016
Brain
Brain Neoplasms
Diffusion Magnetic Resonance Imaging
Female
Glioma
Humans
Image Interpretation, Computer-Assisted
Magnetic Resonance Imaging
Male
Middle Aged
Models, Theoretical
Motion
Perfusion Imaging
Reproducibility of Results
Stroke
English
BACKGROUND AND PURPOSE
Despite a recent resurgence, intravoxel incoherent motion MRI faces practical challenges, including limited SNR and demanding acquisition and postprocessing requirements. A simplified approach using linear fitting of a subset of higher b-values has seen success in other organ systems. We sought to validate this method for evaluation of brain pathology by comparing perfusion measurements using simplified linear fitting to conventional biexponential fitting.
MATERIALS AND METHODS
Forty-nine patients with gliomas and 17 with acute strokes underwent 3T MRI, including DWI with 16 b-values (range, 0-900 s/mm2). Conventional intravoxel incoherent motion was performed using nonlinear fitting of the standard biexponential equation. Simplified intravoxel incoherent motion was performed using linear fitting of the log-normalized signal curves for subsets of b-values >200 s/mm2. Comparisons between ROIs (tumors, strokes, contralateral brain) and between models (biexponential and simplified linear) were performed by using 2-way ANOVA. The root mean square error and coefficient of determination (R2) were computed for the simplified model, with biexponential fitting as the reference standard.
RESULTS
Perfusion maps using simplified linear fitting were qualitatively similar to conventional biexponential fitting. The perfusion fraction was elevated in high-grade (n = 33) compared to low-grade (n = 16) gliomas and was reduced in strokes compared to the contralateral brain (P < .001 for both main effects). Decreasing the number of b-values used for linear fitting resulted in reduced accuracy (higher root mean square error and lower R2) compared with full biexponential fitting.
CONCLUSIONS
Intravoxel incoherent motion perfusion imaging of common brain pathology can be performed by using simplified linear fitting, with preservation of clinically relevant perfusion information.
Despite a recent resurgence, intravoxel incoherent motion MRI faces practical challenges, including limited SNR and demanding acquisition and postprocessing requirements. A simplified approach using linear fitting of a subset of higher b-values has seen success in other organ systems. We sought to validate this method for evaluation of brain pathology by comparing perfusion measurements using simplified linear fitting to conventional biexponential fitting.
MATERIALS AND METHODS
Forty-nine patients with gliomas and 17 with acute strokes underwent 3T MRI, including DWI with 16 b-values (range, 0-900 s/mm2). Conventional intravoxel incoherent motion was performed using nonlinear fitting of the standard biexponential equation. Simplified intravoxel incoherent motion was performed using linear fitting of the log-normalized signal curves for subsets of b-values >200 s/mm2. Comparisons between ROIs (tumors, strokes, contralateral brain) and between models (biexponential and simplified linear) were performed by using 2-way ANOVA. The root mean square error and coefficient of determination (R2) were computed for the simplified model, with biexponential fitting as the reference standard.
RESULTS
Perfusion maps using simplified linear fitting were qualitatively similar to conventional biexponential fitting. The perfusion fraction was elevated in high-grade (n = 33) compared to low-grade (n = 16) gliomas and was reduced in strokes compared to the contralateral brain (P < .001 for both main effects). Decreasing the number of b-values used for linear fitting resulted in reduced accuracy (higher root mean square error and lower R2) compared with full biexponential fitting.
CONCLUSIONS
Intravoxel incoherent motion perfusion imaging of common brain pathology can be performed by using simplified linear fitting, with preservation of clinically relevant perfusion information.
- Language
-
- English
- Open access status
- hybrid
- Identifiers
-
- DOI 10.3174/ajnr.A4929
- PMID 27561834
- Persistent URL
- https://sonar.ch/global/documents/283429
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