Intraoperative ultrasound examination of the brain: possible pitfalls in diagnosis and biopsy guidance.

The use of ultrasound during surgical procedures is frequently beneficial for both demonstration and diagnosis of various pathologic conditions. In the neurosurgical suite, localization of subcortical brain tumors is easily accomplished with real-time imaging. The depth and size of the tumor are easily assessed, and the relationship of the lesion to adjacent normal structures ascertained. However, there are pitfalls that may result in diagnostic inaccuracies during the evaluation of abnormalities. These include artifacts, use of inappropriate equipment, and poor technique. These problems are illustrated and discussed.