Related Experiment Video
Updated: Jun 10, 2026
Automated Midline Shift and Intracranial Pressure Estimation based on Brain CT Images
Published on: April 13, 2013
Removal of CSF pixels on brain MR perfusion images using first several images and Otsu's thresholding technique
Yi-Hsuan Kao1, Michael Mu-Huo Teng, Wen-Yan Zheng
1Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan.
Abstract:
Brain MR perfusion imaging is used to evaluate local perfusion in patients with cerebral vascular disease. Quantitative measurements on the hemodynamic parameters and volume of brain with abnormal perfusion provide an estimation of the severity of the brain perfusion defect. However, quantitative measurements of these focal cerebral hemodynamic parameters are limited by the presence of cerebrospinal fluid (CSF) pixels. We noticed that the CSF has a higher signal than other tissue types on the first perfusion image, which is usually discarded in routine parametric image calculations. This signal difference, however, can be used to segment CSF pixels on the perfusion images. An image division was used to generate ratio images to compensate for spatially dependent signal variation caused by the inhomogeneity of excitation radiofrequency field. By applying an appropriate signal threshold to the ratio images, CSF pixels can be identified and removed from the parametric images. With the removal of CSF pixels, the volume of delayed-perfusion brain parenchyma can be better visualized and the interference from the CSF can be avoided. The proposed technique is simple, fast, automatic, and effective, and no extra scanning is needed to use this technique.
Insights
This study presents a simple method to remove cerebrospinal fluid (CSF) pixels from brain MR perfusion images. This improves visualization of abnormal brain perfusion in patients with cerebrovascular disease.
Area of Science:
- Medical Imaging
- Neuroscience
- Radiology
Background:
- Brain MR perfusion imaging quantifies hemodynamic parameters to assess cerebrovascular disease severity.
- Cerebrospinal fluid (CSF) pixels interfere with accurate quantitative measurements of focal cerebral hemodynamics.
Purpose of the Study:
- To develop and validate a method for segmenting and removing CSF pixels from brain MR perfusion images.
- To improve the visualization and accuracy of quantitative perfusion defect assessment in cerebrovascular disease.
Main Methods:
- Utilized the higher signal of CSF on initial perfusion images for segmentation.
- Employed image division to create ratio images, correcting for radiofrequency field inhomogeneity.
- Applied a signal threshold to ratio images to identify and remove CSF pixels.
Main Results:
- Successfully identified and removed CSF pixels from parametric perfusion images.
- Enhanced visualization of the brain parenchyma with delayed perfusion.
- Eliminated interference from CSF in quantitative analysis.
Conclusions:
- The proposed technique effectively removes CSF interference in brain MR perfusion imaging.
- This simple, fast, and automatic method improves the assessment of brain perfusion defects without additional scanning.
- The technique offers a valuable tool for evaluating patients with cerebrovascular disease.
