Fusion imaging in neurosonology: Clinician’s questions, technical potentials and applicability

Value of ultrasound fusion imaging in detecting vascular cerebral white matter pathology

BACKGROUND

Transcranial sonography is beside magnetic resonance imaging (MRI) and computed tomography, a well-established imaging method for evaluation of brain parenchyma and already implicated in various neurological disorders as bed-side investigation possibility in clinical routine. The aim of this study was the qualitative assessment detecting vascular white matter hyperintensities (WMHs), with ultrasound fusion-imaging technique (UFI) and to find the optimal location for their visualization in accordance to the grade of WMHs and to possibly providing a standardized protocol for clinical use.

RESULTS

29 patients with WMHs of variable degree quantified according to Fazekas grading scale (n = 13 I; n = 9 II; n = 7 III) and 11 subjects with normal findings on MRI were identified for further analysis. Ultrasound images were analyzed to a standardized protocol and predefined anatomical landmarks. UFI could visualize the MRI-verified WMHs in 147 of 161 localizations (91%). The overall ultrasound detection rate of WMHs increased with higher degree of WMHs burden (I:85%, II:94%, III:97%). The highest sensitivity was achieved at the contralateral central part (CPc) (97%) of the lateral ventricle. The inter-rater analysis between 2 independent raters, who were blinded to the patient's diagnosis and assessed only the B-mode ultrasound images, indicated an 86% agreement with an overall moderate strength of agreement (κ: 0.489, p < 0.0005) for all localizations. The highest accordance within raters was shown at the CPc; 92% (κ: 0.645, p < 0.0005).

CONCLUSIONS

This explorative study describes prospectively the ultrasound detection of periventricular vascular WMHs based on MRI lesions using UFI. Transcranial ultrasound (TCS) could serve as an additional screening opportunity for the detection of incidental WMLs during routine TCS investigations to initiate early vascular risk factor modification in primary prevention.