Ashraf Mohamed

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A framework for modeling and predicting anatomical deformations is presented, and tested on simulated images. Although a variety of deformations can be modeled in this framework, emphasis is placed on surgical planning, and particularly on modeling and predicting changes of anatomy between preoperative and intraoperative positions, as well as on(More)
An approach to the deformable registration of three-dimensional brain tumor images to a normal brain atlas is presented. The approach involves the integration of three components: a biomechanical model of tumor mass-effect, a statistical approach to estimate the model's parameters, and a deformable image registration method. Statistical properties of the(More)
Motivated by the need for methods to aid the deformable registration of brain tumor images, we present a three-dimensional (3D) mechanical model for simulating large non-linear deformations induced by tumors to the surrounding encephalic tissues. The model is initialized with 3D radiological images and is implemented using the finite element (FE) method. To(More)
We present an approach for the automatic generation of patient-specific tetrahedral finite-element (FE) meshes from multiple-label segmented medical images. The approach uses a mesh refinement method with guaranteed tetrahedral element quality and includes a post-processing step with operations to change the mesh topol-ogy. Results indicate good(More)
An approach for estimating the deformation of the prostate caused by transrectal ultrasound (TRUS) probe insertion is presented. This work is particularly useful during brachytherapy procedures, in which planning for radioactive seed insertion is performed on preopera-tive scans, and significant deformation of the prostate can occur during the procedure.(More)
A deformable registration method is proposed to register a brain atlas with tumor-bearing brain scans. The tumor mass effect is first simulated in the (normal) atlas, using a biomechanical model of mass effect. The tumor-bearing atlas is subsequently warped to the patient's scan by a deformable registration method, built upon the idea of HAMMER registration(More)
The voltage controlled oscillator (VCO) may be considered one of the most important building blocks in modern communication applications such as microprocessor clock generation, wired and wireless communications, system synchronization, and frequency synthesis. The search in the field of design for high performance VCOs has been increasingly more important(More)
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