Ultra-low dose CT attenuation correction for PET/CT
Autor: | Evren Asma, Bruno De Man, Paul E. Kinahan, Adam M. Alessio, Ting Xia, Ravindra Mohan Manjeshwar |
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Rok vydání: | 2011 |
Předmět: |
PET-CT
Radiological and Ultrasound Technology medicine.diagnostic_test Phantoms Imaging Image quality business.industry Signal-To-Noise Ratio Radiation Dosage Multimodal Imaging Article Positron emission tomography Positron-Emission Tomography Rotational angiography medicine Radiology Nuclear Medicine and imaging Tomography Tomography X-Ray Computed Dose Reduced Nuclear medicine business Correction for attenuation Smoothing |
Zdroj: | Physics in Medicine and Biology. 57:309-328 |
ISSN: | 1361-6560 0031-9155 |
DOI: | 10.1088/0031-9155/57/2/309 |
Popis: | A challenge for positron emission tomography/computed tomography (PET/CT) quantitation is patient respiratory motion, which can cause an underestimation of lesion activity uptake and an overestimation of lesion volume. Several respiratory motion correction methods benefit from longer duration CT scans that are phase matched with PET scans. However, even with the currently available, lowest dose CT techniques, extended duration cine CT scans impart a substantially high radiation dose. This study evaluates methods designed to reduce CT radiation dose in PET/CT scanning. We investigated selected combinations of dose reduced acquisition and noise suppression methods that take advantage of the reduced requirement of CT for PET attenuation correction (AC). These include reducing CT tube current, optimizing CT tube voltage, adding filtration, CT sinogram smoothing and clipping. We explored the impact of these methods on PET quantitation via simulations on different digital phantoms. CT tube current can be reduced much lower for AC than that in low dose CT protocols. Spectra that are higher energy and narrower are generally more dose efficient with respect to PET image quality. Sinogram smoothing could be used to compensate for the increased noise and artifacts at radiation dose reduced CT images, which allows for a further reduction of CT dose with no penalty for PET image quantitation. When CT is not used for diagnostic and anatomical localization purposes, we showed that ultra-low dose CT for PET/CT is feasible. The significant dose reduction strategies proposed here could enable respiratory motion compensation methods that require extended duration CT scans and reduce radiation exposure in general for all PET/CT imaging. |
Databáze: | OpenAIRE |
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