White matter hyperintensities segmentation: a new semi-automated method

Abstract

White matter hyperintensities (WMH) are brain areas of increased signal on T2-weighted or fluid-attenuated inverse recovery magnetic resonance imaging (MRI) scans. In this study we present a new semi-automated method to measure WMH load that is based on the segmentation of the intensity histogram of fluid-attenuated inversion recovery images. Thirty patients with mild cognitive impairment with variable WMH load were enrolled. The semi-automated WMH segmentation included removal of non-brain tissue, spatial normalization, removal of cerebellum and brain stem, spatial filtering, thresholding to segment probable WMH, manual editing for correction of false positives and negatives, generation of WMH map, and volumetric estimation of the WMH load. Accuracy was quantitatively evaluated by comparing semi-automated and manual WMH segmentations performed by two independent raters. Differences between the two procedures were assessed using Student’s t-tests and similarity was evaluated using linear regression model and Dice similarity coefficient (DSC). The volumes of the manual and semi-automated segmentations did not statistically differ (t-value = -1.79, DF = 29, p = 0.839 for rater 1; t-value = 1.113, DF = 29, p = 0.2749 for rater 2), were highly correlated [R2 = 0.921, F(1,29) = 155.54, p < 0.0001 for rater 1; R2 = 0.935, F(1,29) = 402.709, p < 0.0001 for rater 2] and showed a very strong spatial similarity (mean DSC = 0.78, for rater 1 and 0.77 for rater 2). In conclusion, our semi-automated method to measure the load of WMH is highly reliable and could represent a good tool that could be easily implemented in routinely neuroimaging analyses to map clinical consequences of WMH.

Elevated plasma ceramide levels in post-menopausal women

“…Exclusion criteria were: (i) suspicion of cognitive impairment or dementia based on MMSE [21] (score ≤ 26, consistent with normative data collected in the Italian population) and confirmed by a detailed neuropsychological evaluation using the Mental Deterioration Battery [22] and clinical criteria for Alzheimer’s dementia [23] or Mild Cognitive Impairment [24]; (ii) subjective complaints of memory difficulties or other cognitive deficits, regardless of whether or not these interfered with daily life; (iii) vision and hearing loss that could potentially influence testing results; (iv) major medical illnesses (i.e., unstable diabetes; obesity; obstructive pulmonary disease or asthma; hematological and oncological disorders; pernicious anemia; significant gastrointestinal, renal, hepatic, endocrine, or cardiovascular system diseases; recently treated hypothyroidism); (v) current or reported psychiatric disease, as assessed by the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR SCID) [25] or neurological disease, as assessed by clinical evaluation; and (vi) known or suspected history of alcoholism or drug addiction. Finally, because ceramides have been previously involved in the pathogenesis of neurodegenerative disorders [15,26,27], we excluded subjects who showed brain abnormalities or vascular lesions as determined by using a recently published semi-automated method [28]. The menopausal status was prospectively assessed during clinical interviews.…”

Gray and white matter trajectories in patients with bipolar disorder

“…Inclusion criteria for all participants were: (i) age between 18 and 75 years, (ii) at least five years of education, and (iii) suitability for magnetic resonance imaging (MRI) scanning. Exclusion criteria were: (i) history of alcohol or drug abuse in the two years before the assessment, (ii) lifetime drug dependence, (iii) traumatic head injury with loss of consciousness, (iv) past or present major medical illness or neurological disorders, (v) any (for HC) or additional (for patients with BP) psychiatric disorder or mental retardation, (vi) dementia or cognitive deterioration according to DSM‐IV‐TR criteria, and Mini‐Mental State Examination (MMSE) score <25, consistent with normative data in the Italian population , and (vii) any potential brain abnormality or microvascular lesion as apparent on conventional fluid attenuated inversion recovery (FLAIR) scans; in particular, the presence, severity, and location of vascular lesions were computed according to the semi‐automated method recently published by our group .…”

Brain white matter microstructure in deficit and non-deficit subtypes of schizophrenia

“…Exclusion criteria were as follows: (1) history of alcohol or drug abuse in the 2 years before the assessment, (2) lifetime drug dependence, (3) traumatic head injury with loss of consciousness, (4) past or present major medical illness or neurological disorders, (5) any additional psychiatric disorder or mental retardation, (6) dementia or cognitive deterioration according to DSM-IV-TR criteria and Mini-Mental State Examination (MMSE) (Folstein et al, 1975) score lower than 25, consistent with normative data in the Italian population (Measso et al, 1993), and (7) any potential brain abnormality and microvascular lesion as apparent on conventional fluid attenuated inversion recovery (FLAIR) scans; in particular, the presence, severity, and location of vascular lesions were computed according to the semi-automated method recently published by our group (Iorio et al, 2013).…”