Ex-vivo navigation of neurosurgical biopsy needles using microultrasound transducers with M-mode imaging

A clinical need is evident in neurosurgery to facilitate portable, real-time image guidance of interventional tools such as biopsy needles. This work presents imaging studies with microultrasound transducers incorporated into neurosurgical biopsy needles. Two design orientations are shown with the intention to provide both a forward and side field of view to a neurosurgeon. To examine the performance of these needle devices, preliminary B-scans were obtained of resected lamb brain with an embedded target whereby the forward facing and side facing needles were mechanically scanned linearly and radially respectively. The results presented images indicating the feasibility of the transducers to identify a target within brain tissue. To further investigate the transducers potential application as a viable neurosurgical tool, real-time M-mode images were generated within ex vivo porcine brain tissue with an embedded target. Assessing the M-mode images produced by the forward and side facing transducers, the devices are seen to have the potential to offer simple but effective guidance for navigating and positioning the needle within brain tissue close to a target such as a cancerous lesion or in the ventricles.