Towards the automatic computational assessment of enlarged perivascular spaces on brain magnetic resonance images: A systematic review

Enlarged perivascular spaces (EPVS), visible in brain MRI, are an important marker of small vessel disease and neuroinflammation. We systematically evaluated the literature up to June 2012 on possible methods for their computational assessment and analyzed confounds with lacunes and small white matter hyperintensities. We found six studies that assessed/identified EPVS computationally by seven different methods, and four studies that described techniques to automatically segment similar structures and are potentially suitable for EPVS segmentation. T2‐weighted MRI was the only sequence that identified all EPVS, but FLAIR and T1‐weighted images were useful in their differentiation. Inconsistency within the literature regarding their diameter and terminology, and overlap in shape, intensity, location, and size with lacunes, conspires against their differentiation and the accuracy and reproducibility of any computational segmentation technique. The most promising approach will need to combine various MR sequences and consider all these features for accurate EPVS determination. J. Magn. Reson. Imaging 2013;38:774–785. © 2013 Wiley Periodicals, Inc.     

Clinical Research Risk Assessment Among Individuals With Mild Cognitive Impairment

OBJECTIVE:: To determine whether individuals with mild cognitive impairment (MCI) differ from cognitively normal (NC) elders on a risk assessment task and whether participants and their study partners evaluate risk and benefit similarly. DESIGN:: Cross-sectional. SETTING:: University medical setting. PARTICIPANTS:: Seventy-nine participants (NC, n = 40; MCI, n = 39), age 60-90 years (73 ± 7 years; 53% women), and 64 study partners (NC, n = 36; MCI, n = 28), age 38-84 years (68 ± 10 years; 67% women). MEASUREMENTS:: Participants and study partners completed a risk assessment task that involved ranking from least to most risk four hypothetical vignettes for memory loss research (brain autopsy, blood draw, oral medication, neurosurgery). Participants also completed decisional capacity for research and neuropsychological protocols. RESULTS:: MCI participants' risk rankings differed from NC risk rankings (p <0.001) with MCI participants ranking brain autopsy higher and an oral medication trial lower. Demographic, decisional capacity, and neuropsychological variables could not explain MCI participant performances. Participants and their study partners had comparable risk assessment performance (p = 1.0). MCI study partners performed similar to their MCI participant counterparts but were different from NC study partners (p = 0.002; i.e., ranking autopsy higher and oral medication lower). CONCLUSION:: Findings suggest that individuals with MCI assess risk differently than NC peers by overestimating the risk (or underestimating the benefit) of brain autopsy and underestimating the risk (or overestimating the benefit) of oral medication. Study partners display a similar pattern. These observations may be secondary to MCI participants' (and their study partners') personal connection to the potential benefits of an experimental medication for memory loss.     

Familial acquired thrombotic thrombocytopenic purpura in siblings – no immunogenetic link with associated human leucocyte antigens

Acquired immunoglobulin G (IgG)‐mediated thrombotic thrombocytopenic purpura (TTP) has not yet been described in non‐twin siblings. We report two cases of acquired TTP in Caucasian sisters with inactive ADAMTS13 metalloprotease due to ADAMTS13 autoantibodies suggesting a role of genetic determinants in this life‐threatening disease. However, human leucocyte antigen (HLA) class II types presumably associated with acquired TTP were not identified in the patients, indicating that HLA class II typing may not be useful in acquired TTP risk assessment of family members.