Development Of PET/MR High-field Magnetic Resonance RF Coil For Rat Detection

Magnetic resonance imaging(MRI)is a non-invasive technique that is mainly used in medical applications to obtain high quality images of the human body.High-field MRI uses non-ionizing radiation and has a high resolution of soft tissue on any imaging plane,which can provide information on human body morphology and function.In medical diagnostic applications,images of a single modality usually do not provide the doctor with sufficient pathological information.Fusion of images of different modalities(PET images and MRI images)can obtain richer information,which can be more fully understand the comprehensive information of the diseased tissues or organs in order to make an accurate diagnosis or develop a suitable diagnosis and treatment plan.However,the integration of PET into high-field MRI scanners involves a series of key issues,among which solving the electromagnetic interference between PET/MR is the first problem to be solved,because the electromagnetic interaction between these two systems may damage any system's overall performance.The radiofrequency(RF)coil is an important part of the magnetic resonance imaging system,and is a medium used to transmit/receive magnetic resonance signals.Preclinical animal research plays an important role in promoting the application of new noninvasive imaging techniques in tumor detection and disease diagnosis.Due to the differences in PET/MR systems of different small animals,the universal coil cannot meet the needs of the best imaging quality.At present,there is no commercial radiofrequency(RF)coil for PET/MR for small animals.It is of great significance to design and manufacture magnetic resonance special radiofrequency coils for PET/MR.Aiming at the problems of insufficient space,vibration,variable thermal load and electromagnetic interference caused by PET and MR components acquiring data from the same imaging body at the same time,this paper designed a special RF coil for high field magnetic resonance for PET/MR integration to simultaneously obtain molecular and structural information.A dual-channel transceiver-integrated birdcage coil system for PET/MR for rat detection was constructed.First,a simulation study of the design of the radio frequency coil was carried out,and for the biological electromagnetic model,the MR image was used for segmentation to obtain a rat model that matched the individual.Then based on the interface circuit of the radio frequency wire coil system,the circuit principle analysis is carried out,the design and optimization are carried out through the simulation software,and the production of each subcomponent is completed.Based on the modeling and simulation design of the birdcage coil,the production and debugging of the integrated birdcage coil for transmission and reception are completed.Through the experimental research on the water model,the experimental results obtained are consistent with the simulation experiments.The PET/MR compatibility experiment verified the feasibility of the PET / MR high-field RF birdcage coil system designed for rat detection.