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OBJECTIVE To allow non-invasive registration of the bone surface for computer-assisted surgery (CAS), this investigation reports the development and evaluation of intraoperative registration using 2D ultrasound (US) images. This approach employs automatic segmentation of the bone surface reflection from US images tagged with the 3D position to enable the(More)
BACKGROUND Intraventricular lesions are challenging entities that may be difficult to resect completely and safely, especially larger lesions with high vascularity or firm consistency. OBJECTIVE To assess the results of stereotactically guided endoscopic port (SEP) surgery for resection of colloid cysts and intraventricular tumors. METHODS The authors(More)
BACKGROUND AND PURPOSE The authors characterize the detection of additional intracranial metastases in cancer patients at the time of stereotactic radiosurgery (SRS) using a specialized high-resolution magnetic resonance imaging (MRI) protocol. METHODS A retrospective review of 150 consecutive radiosurgical procedures for patients with < or =5 known(More)
An axial-flow ventricular assist device (VAD) under development at the authors' facility is intended for use as a long-term implantable device. At high speeds axial-flow VADs can collapse the native ventricle and damage the heart muscle, lung tissue, and blood. A prototype algorithm was developed to maintain physiologic perfusion to the vital organs while(More)
OBJECT Image-guided frameless stereotactic techniques provide an alternative to traditional head-frame fixation in the performance of fine-needle biopsies. However, these techniques still require rigid head fixation, usually in the form of a head holder. The authors report on a series of fine-needle biopsies and brain abscess aspirations in which a(More)
BACKGROUND AND IMPORTANCE Ependymomas are the most common primary spinal cord tumor, most frequently located near the cauda equina and conus medullaris. We believe that this is the first reported case of a low-grade, nonmyxopapillary (World Health Organization grade 2), intradural, extramedullary ependymoma involving a spinal nerve root. CLINICAL(More)
This paper describes a calibration method for determining the physical location of the ultrasound (US) image plane relative to a rigidly attached 3D position sensor. A calibrated US probe can measure the 3D spatial location of anatomic structures relative to a global coordinate system. The calibration is performed by aiming the US probe at a calibration(More)
An important consideration for clinical application of rotary blood pump based ventricular assist is the avoidance of ventricular collapse due to excessive operating speed. Because healthy animals do not typically demonstrate this phenomenon, it is difficult to evaluate control algorithms for avoiding suction in vivo. An acute hemodynamic study was thus(More)