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Updated: Jun 28, 2026
Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images
Published on: November 20, 2015
MR imaging detection of cerebral microbleeds: effect of susceptibility-weighted imaging, section thickness, and field
R N K Nandigam1, A Viswanathan, P Delgado
1Hemorrhagic Stroke Research Program, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
Background And Purpose:
The emergence of cerebral microbleeds (CMB) as common MR imaging findings raises the question of how MR imaging parameters influence CMB detection. To evaluate the effects of modified gradient recalled-echo (GRE) MR imaging methods, we performed an analysis of sequence, section thickness, and field strength on CMB imaging properties and detection in subjects with cerebral amyloid angiopathy (CAA), a condition associated with microhemorrhage.
Materials And Methods:
Multiple MR images were obtained from subjects with probable CAA, with varying sequences (GRE versus susceptibility-weighted imaging [SWI]), section thicknesses (1.2-1.5 versus 5 mm), and magnetic field strengths (1.5T versus 3T). Individual CMB were manually identified and analyzed for contrast index (lesion intensity normalized to normal-appearing white matter signal intensity) and diameter. CMB counts were compared between 1.5T thick-section GRE and thin-section SWI for 3 subjects who underwent both protocols in the same scanning session.
Results:
With other parameters constant, use of SWI, thinner sections, and a higher field strength yielded medium-to-large gains in CMB contrast index (CI; Cohen d 0.71-1.87). SWI was also associated with small increases in CMB diameter (Cohen d <0.3). Conventional thick-section GRE identified only 33% of CMB (103 of 310) seen on thin-section SWI. Lesions prospectively identified on GRE had significantly greater CI and diameter measured on the GRE image than those not prospectively identified.
Conclusions:
The examined alternatives to conventional GRE MR imaging yield substantially improved CMB contrast and sensitivity for detection. Future studies based on these techniques will most likely yield even higher prevalence estimates for CMB.
Insights
Modified MR imaging techniques significantly improve the detection of cerebral microbleeds (CMB). Susceptibility-weighted imaging (SWI) and thinner sections enhance CMB contrast and sensitivity, leading to higher prevalence estimates in future studies.
Area of Science:
- Radiology
- Neuroimaging
Background:
- Cerebral microbleeds (CMB) are increasingly recognized findings on MR imaging.
- Cerebral amyloid angiopathy (CAA) is a condition frequently associated with microhemorrhages.
Purpose of the Study:
- To investigate how MR imaging parameters affect CMB detection.
- To evaluate modified gradient recalled-echo (GRE) MR imaging methods for improved CMB visualization.
Main Methods:
- MR images were acquired from probable CAA subjects using varying sequences (GRE vs. SWI), section thicknesses (1.2-1.5 mm vs. 5 mm), and field strengths (1.5T vs. 3T).
- CMB contrast index and diameter were analyzed.
- CMB counts were compared between different imaging protocols.
Main Results:
- Susceptibility-weighted imaging (SWI), thinner sections, and higher field strength significantly increased CMB contrast index.
- SWI also showed small increases in CMB diameter.
- Conventional thick-section GRE identified only 33% of CMB compared to thin-section SWI.
Conclusions:
- Modified MR imaging techniques, particularly SWI and thinner sections, substantially improve CMB contrast and detection sensitivity.
- Future studies using these advanced techniques are expected to yield higher CMB prevalence estimates.
