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A new approach of registration in multimodal imaging has been developed. Modalities involved are digital subtracted angiography (DSA, 2D) and magnetic resonance angiography (MRA, 3D). Our approach is an hybrid one, mixing feature and intensity based approaches. This approach is based on the extraction of a anatomical referential common to both MRA and DSA. The results obtained prove the methods efficiency...
The primary goal in this study was to investigate 3-D dose distribution, near the areas of tissue inhomogeneities, in Gamma Knife radiosurgery with the gel dosimetry. The spherical glass balloon of a diameter of 16 cm filled with the gel forms the homogeneous phantom; and an identical balloon with two corks placed on each side to represent the air cavities forms the inhomogeneous phantom. Dose calibration...
This paper presents the identification and the study of the impact of a real-time MRI-based propulsion and tracking system constraints on the step response using a discrete PID controller. A simplified model for such a system accounts for these constraints such as the time delay, the sampling period, and the blood velocity. This application is intended for minimally invasive operations within the...
This work presents the application of a quantitative magnetic resonance imaging (MRI) technique in stereotactic deep-brain neurosurgery planning procedures. The high spatial resolution T1 and T2 maps acquired using this imaging method have been normalized to the standard CJH-27 brain coordinate system and integrated into a neurosurgical visualization and navigation system to improve the accuracy...
Quantitative measurements of tumor volume becomes more realistic with the use of imaging - particularly specially when the tumor have non-ellipsoidal morphology, which remains subtle, irregular and difficult to assess by visual metric and clinical examination. The quantitative measurements depend strongly on the accuracy of the segmentation technique. The validity of brain tumor segmentation methods...
Imaging looks inside the patient's body, exposing the patient's anatomy beyond what is visible on the surface. Medical imaging has a very successful history for medical diagnosis. It also plays an increasingly important role as enabling technology for minimally invasive procedures. Interventional procedures (e.g. catheter based cardiac interventions) are traditionally supported by intra-procedure...
In image-guided surgery and image-directed therapy a plan based on pre-procedure imaging is registered to the patient in the operating or treatment room using a 3D spatial localizer. The plan can be used as long as the transformation between plan and patient remains valid. Most systems use a rigid-body transformation restricting guidance to bony structures (e.g. orthopaedic surgery or maxillo-facial...
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