Patrice Munger

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Magnetic resonance imaging using the echo planar imaging (EPI) technique is particularly sensitive to main (B/sub 0/) field inhomogeneities. The primary effect is geometrical distortion in the phase encoding direction. Here, the authors present a method based on the conjugate gradient algorithm to correct for this geometrical distortion, by solving the EPI(More)
The authors address the use of multimodality imaging as an aid to the planning and guidance of neurosurgical procedures, and discuss the integration of anatomical (CT and MRI), vascular (DSA), and functional (PET) data for presentation to the surgeon during surgery. The authors' workstation is an enhancement of a commercially available system, and in(More)
For perfusion-based functional magnetic resonance imaging, the previously introduced flow-sensitive alternating inversion recovery (FAIR) technique is combined with single-shot RARE (rapid acquisition with relaxation enhancement) and GRASE (gradient and spin echo) imaging sequences. The advantages of these sequences compared to commonly used echo-planar(More)
The relationships between the lactate threshold (TLa), plasma catecholamines, and ventilatory threshold (TVE) were examined under normal and glycogen-depleted conditions. Nine male subjects performed a graded exercise test on a bicycle ergometer in a normal glycogen (NG) state and in a glycogen-depleted (GD) state to determine if manipulation of muscle(More)
An essential component in the execution of image-guided surgery is a hand-held probe whose spatial position is tracked during the procedure and displayed on a three-dimensional operative workstation. This paper describes an experiment performed in order to compare the accuracy of a mechanically linked pointing device (FARO surgical arm) and an optical(More)
Introduction Recently, Elekta linacs have gained the capability to deliver dynamic fields, such as sliding window IMRT or VMAT fields. Because of the potential complexity of such delivery modes, linac QA and patient-specific QA are of prime importance. The aim of this paper is to explain the fundamental concepts of this new mode of operation on Elekta(More)
We address the use of multimodality imaging as an aid to the planning and guidance of neurosurgical procedures, and discuss the integration of anatomical (CT and MRI), vascular (DSA), and functional (PET) data for presentation to the surgeon during surgery. Our workstation is an enhancement of a commercially available system, and in addition to the guidance(More)
We demonstrate the feasibility and utility of using anatomical/vascular correlation in image-guided surgery, by interfacing a PC-based stereoscopic Digital Subtraction Angiography (DSA) analysis system to a three-dimensional (3D) image based surgical workstation that has been modified to allow presentation of stereoscopic images. Numerical values(More)
This thesis presents the design, implementation and testing of a perfusion-weighted magnetic resonance imaging sequence that is capable of acquiring several slices at a time. Various methods of image acquisition and perfiision contrast generation are considered and tested. The results of multi-slice acquisitions are compared with those from single-slice(More)
PURPOSE Existing commercial 2D/3D array detectors for patient-specific VMAT QA are not suitable for stereotactic plans because of the poor spatial resolution of the embedded detectors. A pre-treatment QA method was developed to perform a complete 3D patient dose analysis of stereotactic VMAT plans using Sun Nuclear 3DVH software and a high resolution EPID(More)