BACKGROUND AND PURPOSE: Diameter measurement of the third ventricle with magnetic resonance imaging (MRI) and recently also with transcranial sonography (TCS) has emerged as a surrogate marker for brain atrophy and disease progression in multiple sclerosis (MS). This study aims to evaluate TCS measurements of the third ventricle diameter in a clinical routine setting against MRI. METHODS: Transverse diameters of the third ventricle were determined in 27 MS patients using both, TCS and MRI. In TCS, the distance between the leading edges of the brain-ventricle interfaces was assessed in axial image planes. In MRI, the transverse diameter of the mid-portion of the third ventricle was measured on axial T1-weighted images. RESULTS: The mean diameter of the third ventricle was 4.0 mm (SD 1.7 mm), when measured with MRI, and 4.4 mm (SD 1.7 mm), when measured with TCS. The 95% limits of agreement of the Bland-Altman Plot were 2.93 mm (95% CI 2.08 to 3.78 mm) and -2.23 mm (95%CI -3.08 to -1.38 mm). Pearson correlation coefficient was .71 (P < .0001). CONCLUSIONS: TCS may appear suitable as screening examination for the extent of brain atrophy at a single-point study, but at least in the early stages of the disease, TCS is not useful to monitor disease progression.
BACKGROUND AND PURPOSE: Diameter measurement of the third ventricle with magnetic resonance imaging (MRI) and recently also with transcranial sonography (TCS) has emerged as a surrogate marker for brain atrophy and disease progression in multiple sclerosis (MS). This study aims to evaluate TCS measurements of the third ventricle diameter in a clinical routine setting against MRI. METHODS: Transverse diameters of the third ventricle were determined in 27 MSpatients using both, TCS and MRI. In TCS, the distance between the leading edges of the brain-ventricle interfaces was assessed in axial image planes. In MRI, the transverse diameter of the mid-portion of the third ventricle was measured on axial T1-weighted images. RESULTS: The mean diameter of the third ventricle was 4.0 mm (SD 1.7 mm), when measured with MRI, and 4.4 mm (SD 1.7 mm), when measured with TCS. The 95% limits of agreement of the Bland-Altman Plot were 2.93 mm (95% CI 2.08 to 3.78 mm) and -2.23 mm (95%CI -3.08 to -1.38 mm). Pearson correlation coefficient was .71 (P < .0001). CONCLUSIONS:TCS may appear suitable as screening examination for the extent of brain atrophy at a single-point study, but at least in the early stages of the disease, TCS is not useful to monitor disease progression.