Ultrasound-controlled neuronavigator-guided brain surgery

Abstract

The development of a unique neurosurgical navigator is described and a preliminary series of seven cases of intracerebral lesions approached with the assistance of this neuronavigation system under ultrasound control is presented. The clinical series included five low-grade astrocytomas, one chronic intracerebral hematoma, and one porencephalic cyst. Management procedures included biopsy in all cases, drainage of the hematoma, and endoscopy and fenestration for the cyst. The features of the neuronavigation system are interactive reconstructions of preoperative computerized tomography and magnetic resonance imaging data, corresponding intraoperative ultrasound images, versatility of the interchangeable end-effector instruments, graphic presentation of instruments on the reconstructed images, and voice control of the system. The principle of a common axis in the reconstructed images served to align the navigational pointer, biopsy guide, endoscope guide, ultrasound transducer, and surgical microscope to the brain anatomy. Intraoperative ultrasound imaging helped to verify the accuracy of the neuronavigator and check the results of the procedures. The arm of the neuronavigation system served as a holder for instruments, such as the biopsy guide, endoscope guide, and ultrasound transducer, in addition to functioning as a navigational pointer. Also, the surgical microscope was aligned with the neuronavigator for inspection and biopsy of the hematoma capsule to rule out tumor etiology. Voice control freed the neurosurgeon from manual exercises during start-up and calibration of the system.

Evaluation of Intraoperative Brain Shift Using an Ultrasound-Linked Navigation System for Brain Tumor Surgery

“…Various groups have connected US scanners with conventional navigation systems. 3,6,10,13,23) II. Advantages of a US-linked navigation system (synchronized navigation) The present US-linked navigation system was used during 75 surgical procedures in 64 patients with brain tumor.…”

“…This disadvantage can be compensated by comparing the real-time US images with the corresponding images from preoperative CT or MR images using the navigation system. 4,10,13,16) Improved understanding of US images was obtained in about 90% of fair or poor US images. The borders of the tumors could be clearly identified in glioma patients with good US images, but not in glioma patients with fair or poor US images.…”

“…11,17) US scanners have been combined with a navigation system to display real-time US images with the corresponding preoperative images. 3,6,10,13,23) We previously introduced a US-linked navigation system into brain tumor surgery to evaluate intraoperative brain shift and allow real-time navigation based on intraoperative US images and preoperative CT or MR images.…”

Towards a Guidance System to Aid in the Dosimetry Calculation of Intraoperative Electron Radiation Therapy

“…Nevertheless, these systems are usually voluminous, can only position a single device and present sterilization problems. Other techniques make use of ultrasound transducers [6][7][8]. However, due to their natural dependency on humidity and ambient temperature, they do not offer the required accuracies.…”

Detection of the spatial accuracy of a magnetic resonance and surgical computed tomography scanner in the region of surgical interest

“…These advantages have led to safer operations and to shorter recovery times. [1][2][3][4] Usually, IGS uses preoperative image data of the patient 3 meaning that the surgeon has to take into account the possible image distortions and artifacts 5 and also changes that occur in the patient's anatomy during operations. Other sources that affect the quality of IGS include technical accuracy, registration accuracy, and application accuracy.…”