Visual Assessment of Age-Related White Matter Hyperintensities Using FLAIR Images at 3 T: Inter- and Intra-Rater Agreement.

BACKGROUND: Age-related white matter hyperintensities are frequent incidental findings on T2-weighted brain MRI, and they are evaluated in clinical practice using a visual rating scale. OBJECTIVE: To evaluate inter- and intra-rater agreement in MRI visual evaluations of age-related white matter hyperintensities made by two radiologists with different levels of experience using a visual rating scale. METHODS: Two radiologists of two different levels of experience separately rated age-related white matter hyperintensities in 40 consecutive 3-tesla brain MRI scans using the Fazekas and Schmidt visual rating scale. Ratings were made on axial FLAIR (fluid-attenuated inversion recovery) sequences. Two readings were made by each radiologist. Intra- and inter-rater agreement was statistically determined by using Cohen's weighted kappa analysis. RESULTS: Forty patients (21 females, 19 males; mean age = 57 ± 18.43 years) were included between September and October 2011. Mean values ± SD for visual scores were as follows: periventricular hyperintensities, between 1.175 ± 0.9 and 1.375 ± 0.89; number of deep white matter hyperintensity lesions, between 1.325 ± 1.18 and 1.575 ± 1.15, and extent of deep white matter hyperintensity lesions, between 0.925 ± 0.78 and 1.1 ± 0.74. Intra- and inter-rater agreement was very good (x03BA; values, 0.85-0.91 and 0.80-0.97, respectively) for each of the three visual scale criteria, with significant correlations between ratings (r = 0.95; p < 0.0001) and readings (r = 0.91; p < 0.0001). CONCLUSION: Visual assessment of age-related white matter hyperintensities by radiologists using a visual scale on FLAIR sequence is reproducible. Differences in experience level do not influence readings. Visual scale use is thus justified in common practice.

Brain magnetic resonance imaging findings in cryptogenic stroke patients under 60 years with patent foramen ovale.

PURPOSE: To compare magnetic resonance imaging (MRI) brain feature in cryptogenic stroke patients with patent foramen ovale (PFO), cryptogenic stroke patients without PFO and patients with cardioembolic stroke. MATERIALS AND METHODS: The ethics committee required neither institutional review board approval nor informed patient consent for retrospective analyses of the patients' medical records and imaging data. The patients' medical files were retrospectively reviewed in accordance with human subject research protocols. Ninety-two patients under 60 years of age were included: 15 with cardioembolic stroke, 32 with cryptogenic stroke with PFO and 45 with cryptogenic stroke without PFO. Diffusion-weighted imaging of brain MRI was performed by a radiologist blinded to clinical data. Univariate, Fischer's exact test for qualitative data and non-parametric Wilcoxon test for quantitative data were used. RESULTS: There was no statistically significant difference found between MRI features of patients with PFO and those with cardioembolic stroke (p<.05). Patients without PFO present more corticosubcortical single lesions (p<.05) than patients with PFO. Patients with PFO have more often subcortical single lesions larger than 15mm, involvement of posterior cerebral arterial territory and intracranial occlusion (p<.05) than patients with cryptogenic stroke without PFO. CONCLUSION: Our study suggests a cardioembolic mechanism in ischemic stroke with PFO.