International journal of computer assisted radiology and surgery
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Int J Comput Assist Radiol Surg · Jul 2014
MRI-compatible positioning device for guiding a focused ultrasound system for transrectal treatment of prostate cancer.
High-intensity focused ultrasound (HIFU) is a promising treatment method for many common cancers, including prostate cancer. Magnetic resonance image (MRI) guidance of HIFU permits targeting and monitoring of therapy. A prototype MRI-compatible positioning device that navigates a HIFU transducer was designed, fabricated and tested. ⋯ An MRI-compatible HIFU positioning system was developed that has the ability to create thermal lesions with MRI guidance for endorectal treatment of prostate cancer.
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Int J Comput Assist Radiol Surg · Jan 2014
Electrode localization for planning surgical resection of the epileptogenic zone in pediatric epilepsy.
In planning for a potentially curative resection of the epileptogenic zone in patients with pediatric epilepsy, invasive monitoring with intracranial EEG is often used to localize the seizure onset zone and eloquent cortex. A precise understanding of the location of subdural strip and grid electrodes on the brain surface, and of depth electrodes in the brain in relationship to eloquent areas is expected to facilitate pre-surgical planning. ⋯ In comparison with previously reported approaches, our algorithm is able to achieve more accurate alignment of strip and grid electrodes with minimal user input. Unlike manual alignment procedures, our algorithm achieves excellent alignment without time-consuming and difficult judgements from an operator.
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Int J Comput Assist Radiol Surg · Jan 2014
Assessing performance in brain tumor resection using a novel virtual reality simulator.
NeuroTouch is a virtual reality (VR) simulator developed for neurosurgical skill training. Validation demonstrating that the system is useful and reliable is required for formal adoption into training curriculums. Face and content validity have been demonstrated for some neurosurgical simulators, but construct validity remains difficult to establish. A pilot validation study was conducted for a NeuroTouch training exercise. ⋯ We have conducted a pilot validation study for the NeuroTouch tumor resection scenario and demonstrated for the first time, face, content and construct validity of a VR neurosurgical simulation exercise. Future full-scale studies will be conducted in noncompetitive settings and incorporate expert participants.
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Int J Comput Assist Radiol Surg · Nov 2013
Optimized order estimation for autoregressive models to predict respiratory motion.
To successfully ablate moving tumors in robotic radio-surgery, it is necessary to compensate for motion of inner organs caused by respiration. This can be achieved by tracking the body surface and correlating the external movement with the tumor position as it is implemented in the CyberKnife[Formula: see text] Synchrony system. Tracking errors, originating from system immanent time delays, are typically reduced by time series prediction. Many prediction algorithms exploit autoregressive (AR) properties of the signal. Estimating the optimal model order [Formula: see text] for these algorithms constitutes a challenge often solved via grid search or prior knowledge about the signal. ⋯ The overall results suggest that using AIC to estimate the model order [Formula: see text] for prediction algorithms based on AR properties is a valid method which avoids intensive grid search and leads to high prediction accuracy.
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Int J Comput Assist Radiol Surg · Sep 2013
Ultrasound-guided facet joint injection training using Perk Tutor.
Facet syndrome is a condition that may cause 15-45 % of chronic lower back pain. It is commonly diagnosed and treated using facet joint injections. This needle technique demands high accuracy, and ultrasound (US) is a potentially useful modality to guide the needle. US-guided injections, however, require physicians to interpret 2-D sonographic images while simultaneously manipulating an US probe and needle. Therefore, US-guidance for facet joint injections needs advanced training methodologies that will equip physicians with the requisite skills. ⋯ The results of this pilot study suggest that Perk Tutor provides an improved training environment for US-guided facet joint injections on a synthetic model.