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Updated: Aug 4, 2025
Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images
Published on: November 20, 2015
Implications of quantitative susceptibility mapping at 7 Tesla MRI for microbleeds detection in cerebral small vessel
Valentina Perosa1, Johanna Rotta2, Renat Yakupov3,4
1J. Philip Kistler Stroke Research Center, Massachusetts General Hospital, Boston, MA, United States.
Background:
Cerebral microbleeds (MBs) are a hallmark of cerebral small vessel disease (CSVD) and can be found on T2*-weighted sequences on MRI. Quantitative susceptibility mapping (QSM) is a postprocessing method that also enables MBs identification and furthermore allows to differentiate them from calcifications.
Aims:
We explored the implications of using QSM at submillimeter resolution for MBs detection in CSVD.
Methods:
Both 3 and 7 Tesla (T) MRI were performed in elderly participants without MBs and patients with CSVD. MBs were quantified on T2*-weighted imaging and QSM. Differences in the number of MBs were assessed, and subjects were classified in CSVD subgroups or controls both on 3T T2*-weighted imaging and 7T QSM.
Results:
48 participants [mean age (SD) 70.9 (8.8) years, 48% females] were included: 31 were healthy controls, 6 probable cerebral amyloid angiopathy (CAA), 9 mixed CSVD, and 2 were hypertensive arteriopathy [HA] patients. After accounting for the higher number of MBs detected at 7T QSM (Median = Mdn; Mdn7T-QSM = 2.5; Mdn3T-T2 = 0; z = 4.90; p < 0.001) and false positive MBs (6.1% calcifications), most healthy controls (80.6%) demonstrated at least one MB and more MBs were discovered in the CSVD group.
Conclusions:
Our observations suggest that QSM at submillimeter resolution improves the detection of MBs in the elderly human brain. A higher prevalence of MBs than so far known in healthy elderly was revealed.
Insights
Quantitative susceptibility mapping (QSM) at submillimeter resolution significantly improves the detection of cerebral microbleeds (MBs) in elderly individuals. This advanced MRI technique reveals a higher prevalence of MBs in healthy older adults than previously understood.
Area of Science:
- Neuroimaging
- Radiology
- Neurology
Background:
- Cerebral microbleeds (MBs) are key indicators of cerebral small vessel disease (CSVD).
- Standard MRI sequences like T2*-weighted imaging detect MBs, but Quantitative Susceptibility Mapping (QSM) offers enhanced identification and differentiation from calcifications.
Purpose of the Study:
- To investigate the utility of submillimeter resolution QSM for detecting MBs in the context of CSVD.
- To compare MB detection rates between QSM and traditional T2*-weighted imaging at different magnetic field strengths (3T and 7T).
Main Methods:
- MRI scans (3T and 7T) were acquired from elderly participants, including healthy controls and patients with CSVD.
- MBs were quantified using both T2*-weighted imaging and QSM.
- Statistical analyses compared MB counts and classified subjects into CSVD subgroups or control groups based on imaging findings.
Main Results:
- 7T QSM detected significantly more MBs compared to 3T T2*-weighted imaging (Mdn7T-QSM = 2.5 vs. Mdn3T-T2 = 0; p < 0.001).
- A notable percentage of calcifications (6.1%) were identified as false positive MBs by QSM.
- After accounting for false positives, 80.6% of healthy controls showed at least one MB, and the CSVD group exhibited a higher overall MB burden.
Conclusions:
- Submillimeter resolution QSM enhances the detection of MBs in the elderly brain.
- The study reveals a previously underestimated prevalence of MBs in the healthy elderly population.
