Study of Different Gating Techniques for PET Image of Lung and Liver Lesions

Study Overview
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Brief Summary
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Lesions blurred by respiratory motion are common in fluorine-18 PET/CT studies. To avoid these artefacts, several standard gating correction technics are available. the investigator aimed to compare the impact of different gating techniques based on phase, amplitude, elastic-motion monitored with and without pressurre sensor device on standardized uptake value (SUVmax and SUVpeak) and uptake volume (UV) measurements on different sizes of pulmonary and liver lesions. The feasability of this study will be done using anthropomorphic coupled with a motion phantom and on a series of patients.

Detailed Description
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PET-CT images will be acquired on a Biograph Vision600 PET/CT, fitted with 26cm axial field of view and time of flight. Phantom study will use an anthropomorphic TORSO phantom with a programmable motion phantom, mimicking respiratory motion (QUASAR). Spheres with various internal diameters will be introduce into the lungs (air density) adding an axial mechanical device simulating breathing movement of +/-20mm. Concentration in the spheres will be the same for all diameters. The background and liver activities will be approximatively respectively 38 and 14 MBq. This phantom will be a simulating patient only for lung lesions. The investigator will compare 6 different PET acquisitions: standard 3min acquisition without movement as our reference of trues SUVmax and UV, 3min acquisition with simulated breathing movement without any gating and 3min with respectively gating techniques based on phase, amplitude, elastic-motion monitored with and without pressurre sensor device. Patient study will be on 50 consecutive patients with lung or liver nodules. 18F-FDG injection will be around 2.5 MBq/kg. The investigator will compare 5 different PET acquisitions: standard acquisition with free respiratory movement as our reference of trues SUVmax and UV, acquisitions with respectively gating techniques based on phase, amplitude, elastic-motion monitored with and without pressurre sensor device.

Official Title
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Study of Different Gating Techniques of Positron Emission Tomography Acquisition Focus on Lung or Liver Nodules. Comparaison on Phantoms and a Series of Patients

Conditions
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Lung; Nodule, Liver Metastases

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: presence at least of one hepatic or lung nodule Exclusion Criteria: none

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of the different gating systems in lung lesions visualization | Classification, based on a phantom and patients studies, of the different gating system in view of the volume and SUV (max and peak) modification for lung lesions | Inclusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of the different gating systems in liver lesions visualization | Classification, based on a patients studies, of the different gating system in view of the volume and SUV (max and peak) modification for liver lesions | Inclusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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positron emission tomography, nodule uptake, gating, quantification