Toshinori Hirai MD, Presenter: Nothing to Disclose

Hiroyuki Uetani, Abstract Co-Author: Nothing to Disclose

Mamoru Hashimoto, Abstract Co-Author: Nothing to Disclose

Manabu Ikeda, Abstract Co-Author: Nothing to Disclose

Mika Kitajima MD, Abstract Co-Author: Nothing to Disclose

Yasuyuki Yamashita MD, Abstract Co-Author: Nothing to Disclose

To determine the prevalence and topography of microbleeds (MBs) on susceptibility-weighted imaging (SWI) at 3T in a cohort of patients attending a university hospital memory clinic.

We included 230 consecutive patients (82 men, 142 women, mean age 74±8.6 years) who attended a memory clinic between January 2008 and March 2010. All underwent dementia screening, neurologic, psychiatric, comprehensive neuropsychiatric assessments, and 3-T MRI study including SWI of the brain. They were divided into 6 groups, a subjective complaints (SC), a mild cognitive impairment (MCI), an Alzheimer disease (AD), a dementia with Lewy bodies (DLB), a vascular dementia (VaD), and a frontotemporal lobar dementia (FTLD) group. When all clinical findings were normal, complaints were considered to be subjective. In each case, 2 neuroradiologists consensually evaluated the number and location of MBs defined as small (<10 mm diameter) round foci of low signal intensity on SWI. Statistical multiple comparisons were performed to test differences among the groups.

At least one MB was found in 100 patients (43.5%). The prevalence of MBs differed among the groups (p < 0.0001); 95% of patients with VaD, 52% with DLB, 43% with MCI, 42% with AD, 21% with FTLD, and 15% with SC manifested MBs. There was no significant difference between patients with FTLD and SC. In all groups the MBs tended to arise in the lobe; there was no significant topographic difference among the MCI, AD, DLB, and VaD groups.

The prevalence of MBs on SWI at 3T was higher than previously reported for T2*-weighted imaging. The MB topography did not differ among the MCI, AD, DLB, and VaD groups.

The finding of a high proportion of MBs in patients with MCI, AD and DLB provides further evidence for the involvement of vascular factors in these neurodegenerative diseases.

Hirai, T, Uetani, H, Hashimoto, M, Ikeda, M, Kitajima, M, Yamashita, Y, Prevalence and Topography of Microbleeds on Susceptibility-weighted Imaging at 3 T in a University Hospital-based Dementia Study.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11006352.html