Related Experiment Video
Updated: Aug 17, 2026
Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
Published on: December 18, 2016
MRI measurements of water diffusion: impact of region of interest selection on ischemic quantification
Yelda Ozsunar1, Kutsi Koseoglu, Thierry A G M Huisman
1Department of Radiology, School of Medicine, Adnan Menderes University, Aydin 09100, Turkey. yozsunar@adu.edu.tr
Objective:
To investigate the effect of ADC heterogeneity on region of interest (ROI) measurement of isotropic and anisotropic water diffusion in acute (< 12 h) cerebral infarctions.
Methods And Materials:
Full diffusion tensor images were retrospectively analyzed in 32 patients with acute cerebral infarction. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured in ischemic lesions and in the corresponding contralateral, normal appearing brain by using four ROIs for each patient. The 2 x 2 pixel square ROIs were placed in the center, the lateral rim and the medial rim of the infarction. In addition, the whole volume of the infarction was measured using a free hand method. Each ROI value obtained from the ischemic lesion was normalized using contralateral normal ROI values.
Results:
The localization of the ROIs in relation to the ischemic lesion significantly affected ADC measurement (P < 0.01, using Friedman test), but not FA measurement (P = 0.25). Significant differences were found between ADC values of the center of the infarction versus whole volume (P < 0.01), and medial rim versus whole volume of infarction (P < 0.001) with variation of relative ADC values up to 11%. The differences of absolute ADC for these groups were 22 and 23%, respectively. The lowest ADC was found in the center, followed by medial rim, lateral rim and whole volume of infarction.
Conclusion:
ADC quantification may provide variable results depending on ROI method. The ADC and FA values, obtained from the center of infarction tend to be lower compared to the periphery. The researchers who try to compare studies or work on ischemic quantification should be aware of these differences and effects.
Insights
Apparent diffusion coefficient (ADC) measurements in acute cerebral infarction vary based on region of interest (ROI) placement. The center of the infarction shows lower ADC values than the periphery, impacting study comparisons.
Area of Science:
- Radiology
- Neuroimaging
- Medical Physics
Background:
- Diffusion tensor imaging (DTI) is crucial for evaluating acute cerebral infarction.
- Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) quantify water diffusion.
- Understanding ADC heterogeneity is vital for accurate lesion characterization.
Purpose of the Study:
- To assess the impact of region of interest (ROI) placement on ADC and FA measurements in acute cerebral infarctions.
- To investigate ADC heterogeneity within ischemic lesions.
Main Methods:
- Retrospective analysis of DTI data from 32 acute cerebral infarction patients.
- Measurement of ADC and FA values using standardized ROIs (center, rims, whole volume) and freehand methods.
- Normalization of lesion ROI values against contralateral normal brain tissue.
Main Results:
- ROI localization significantly affected ADC measurements (P < 0.01), but not FA (P = 0.25).
- ADC values varied up to 11% between center and whole volume measurements.
- The lowest ADC values were consistently found in the center of the infarction.
Conclusions:
- ADC quantification is sensitive to ROI selection methodology in acute cerebral infarction.
- ADC and FA values tend to be lower in the infarction center compared to peripheral regions.
- Awareness of these measurement variations is essential for comparative research and clinical quantification.
