Intraoperative Three-Dimensional Ultrasonography: An Approach to Register Brain Shift using Multidimensional Image Processing

Abstract

Neuronavigation uses the skull as a reference system for transfer of image-space data to physical space during brain surgery. This requires a stable spatial relation between the skull and intracranial structures. However, especially dura opening and preparation for lesion removal causes brain shift. This shift may mislead the surgeon unless preoperatively defined image-space data are corrected for shifting online intraoperatively. Since a real-time modality is required intraoperatively, we propose three-dimensional (3 D) ultrasonography for detection of brain shift. By coupling common ultrasound probes (3.5/6.5 MHz) to a magnetic digitizer receiver 2 D-ultrasound scans were obtained intraoperatively along with their spatial orientation. 3 D-ultrasonography was achieved by alignment of sequentially obtained 2 D-scans. For multimodal matching, preoperative MRI data was segmented for landmarks (cerebral ventricles, lesion) automatically. The 3 D-ultrasonography data set scanned intraoperatively was contoured and matched with the MRI data set. Intraoperative 3 D-ultrasonography revealed excellent delineation of landmarks in almost real time in six patients studied. Matching of MRI data and intraoperative 3 D-ultrasonography data was successful with good correspondence of landmarks. Intraoperative 3 D-ultrasonography is proposed as a promising tool for on-line detection of brain shift during intracranial operations.

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

“…US imaging has seen a recent revival with improved image quality and new technical developments. 11,17) Therefore, US may provide a solution to brain shift based on obtaining real-time information. Various groups have connected US scanners with conventional navigation systems.…”

“…3D US images may solve the problems with the image quality and orientation experienced with 2D US. 11,24) However, we think that the 2D US images in this US-linked navigation system were useful for evaluation of brain shift and extent of tumor resection.…”

“…Recent technological advances in US scanners have lead to reevaluation of the advantages of US for intraoperative use. 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.…”

Reconstruction of Sphenoid Wing Dysplasia with Pulsating Exophthalmos in a Case of Neurofibromatosis Type 1 Supported by Intraoperative Navigation Using a New Skull Reference System

“…Problem-oriented solutions for this problem involve intricate measures like intraoperative MR-or CT-imaging or the data transfer of navigated ultrasound information. 11,12 With high-contrast structures, fluoroscopic systems enable intraoperative three-dimensional imaging, and they are easy to use and familiar. 13 Preoperatively in our patient it was unclear whether the planned approach would be adequate or whether a more extended approach would be needed.…”

Ultrasound/MRI Overlay with Image Warping for Neurosurgery

“…The corresponding oblique slice can be extracted from the pre-operative MRI image volume for comparison. This basic technique has been demonstrated by several groups [5,6,7,8]. Our previous contributions include a comprehensive study of this technique involving both phantom work and several clinical procedures [9,10,11].…”