Spatial priors, such as probabilistic atlases, play an important role in MRI segmentation. However, the availability of comprehensive, reliable and suitable manual segmentations for atlas construction is limited. We therefore propose a joint segmentation of corresponding, aligned structures in the entire population that does not require a probability atlas. Instead, a latent atlas, initialized ...

We describe the design and operational experience of the ATLAS production system as implemented for execution on Grid3 resources. The execution environment consisted of a number of grid-based tools: Pacman for installation of VDT-based Grid3 services and ATLAS software releases, the Capone execution service built from the Chimera/Pegasus virtual data system for directed acyclic graph (DAG) gene...

Absolute dosimetry with ionization chambers of the narrow photon fields used in stereotactic techniques and IMRT beamlets is constrained by lack of electron equilibrium in the radiation field. It is questionable that stopping-power ratio in dosimetry protocols, obtained for broad photon beams and quasi-electron equilibrium conditions, can be used in the dosimetry of narrow fields while keeping ...

We present a new standard atlas of the human brain based on magnetic resonance images. The atlas was generated using unbiased population registration from high-resolution images obtained by multichannel-coil acquisition at 3T in a group of 24 normal subjects. The final atlas comprises three anatomical channels (T(1)-weighted, early and late spin echo), three diffusion-related channels (fraction...

We present a hierarchical object–based deformable atlas, a promising new approach for the automatic localization and quantitative analysis of neuroanatomy in MR images. The 3D finite element-based elastic atlas combines the advantages of both volumetric– and surface– based deformable atlases in one single unifying framework. This multiresolution framework is not only capable of deforming entire...

∗ Undergraduate Research Participants Abstract Argonne’s ATLAS (Argonne Tandem-Linac Accelerator System) control system comprises two separate database concepts. The first is the distributed real-time database structure provided by the commercial product Vsystem [1]. The second is a more static relational database archiving system designed by ATLAS personnel using Oracle Rdb [2] and Corel Parad...

Introduction: Multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. In this work, we investigated MR-based MAGIC gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. Materials and Methods: A heterogeneous slab phantom including bones was made....

A semi-supervised segmentation method using a single atlas is presented in this paper. Traditional atlas-based segmentation suffers from either a strong bias towards the selected atlas or the need for manual effort to create multiple atlas images. Similar to semi-supervised learning in computer vision, we study a method which exploits information contained in a set of unlabelled images by mutua...

UNLABELLED In some patients with well-differentiated thyroid carcinoma, dosimetry is necessary to avoid toxicity from therapy and to guide prescription of the administered activity of radioiodine. METHODS The presentations and courses of 2 patients exemplify the points. In the second patient, the clues to the need for dosimetry were the large size of the tumor and high circulating levels of t...

In-vivo dosimetry techniques are currently being applied only by a few Centers because they require time-consuming implementation measurements, and workload for detector positioning and data analysis. The transit in-vivo dosimetry performed by the electronic portal imaging device (EPID) avoids the problem of solid-state detector positioning on the patient. Moreover, the dosimetric characterizat...