Attenuation and scatter correction for in-beam positron emission tomography monitoring of tumour irradiations with heavy ions
| Autor: | Wolfgang Enghardt, Falk Pönisch, K. Lauckner |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Physics::Medical Physics
Monte Carlo method Heavy Ion Radiotherapy Iterative reconstruction Sensitivity and Specificity Imaging phantom Imaging Three-Dimensional Optics Image Interpretation Computer-Assisted medicine Humans Scattering Radiation Radiology Nuclear Medicine and imaging Carbon Radioisotopes Positron emission Radiometry Physics Radiological and Ultrasound Technology medicine.diagnostic_test business.industry Attenuation Reproducibility of Results Radiotherapy Dosage Radiotherapy Computer-Assisted Radiography Head and Neck Neoplasms Positron emission tomography Tomography business Monte Carlo Method Correction for attenuation Algorithms Tomography Emission-Computed |
| Zdroj: | Physics in Medicine and Biology. 48:2419-2436 |
| ISSN: | 1361-6560 0031-9155 |
| DOI: | 10.1088/0031-9155/48/15/312 |
| Popis: | An in-beam dual-head positron camera is used to monitor the dose application in situ during the tumour irradiation with carbon ion beams at the experimental heavy ion therapy facility at GSI Darmstadt. Therefore, a positron emission tomograph has been mounted directly at the treatment site. A fully 3D reconstruction algorithm based on the maximum likelihood expectation maximization (MLEM) algorithm has been developed and adapted to this spatially varying imaging situation. The scatter and attenuation correction are included in the forward projection step of the maximum likelihood image reconstruction. This requires an attenuation map containing the information on the material composition and densities. This information is derived from the x-ray computed tomograms of the patient and the patient fixation system including the head-rest. The normalization of scattered events relative to the unscattered events is done by a global scatter fraction factor which is estimated by means of a Monte Carlo simulation. The feasibility of the proposed algorithm is shown by means of computer simulations, phantom measurements as well as patient data. |
| Databáze: | OpenAIRE |
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