Scan Protocol Research And Application Of Superconducting MRI In Dogs

MRI has become the chief imaging technique for central nervous system?CNS?diseases because of its excellent soft tissue contrast.This article introduces the latest development in MRI,which include MRI contrast enhancement technology as well as MRI manifestations of CNS diseases.This research aimed to form a scan protocol dedicated for superconducting MRI and investigate it's diagnostic value.The purpose of study first was to explore the scan protocol of 1.5 T MRI in dog,then to describe the characteristics and signal intensity of various organs based on acquired image and established a MRI Atlas of normal anatomy.The method was to scan the head,spine,thorax,abdomen and joints of 12 healthy dogs,respectively.MRI sequence included T₂WI FSE,T₁WI FSE,PDW FSE,T₁WI 3D GRE,T₂*WI GRE,FLAIR,STIR,T₁WI SE,3D-CISS,etc.Results showed that multi-parameter images of the dog's CNS,muscles,major organs and joints as well as small organs could be obtained through this scan strategy.Motion artifact was more significant during thoracic and abdominal scans.This study had described the MRI features of the head,spine,major joints,thorax,abdomen and other tissues or organs.Also a MRI Atlas of normal anatomy was established based on the high quality images of each part.The purpose of study second was to explore the relationship between scan parameters and image quality and evaluate the contrast effect of Gd-DTPA.Then analyzed the characteristics of common MRI artifacts and coping strategies.The method was to scan head,thorax,abdomen,joints and other body parts of 8 dogs with sequences included T₁WI SE/FSE,T₂WI FSE,FLAIR,STIR,T₁WI 3D GRE.Compared the effects of FOV,ETL,NSA,matrix,fat set technique and receive coil on image contrast,SNR,resolution,acquired time or artifacts.Eight dogs received Gd-DTPA 0.2 mL/Kg i.v.and scanned head transversal T₁WI SE and T₁WI 3D GRE sequences when finished injection.The Matlab synthesis map was used to compare the T₁WI SE and T₁WI 3D GRE image before and after angiography.A retrospective study of 15,000 animal clinical images was performed.Typical artifacts were selected for classification based on the cause,and image features and improvement measures were analyzed.The results showed that upon parameters will influence the quality of image.The Matlab composite map showed that the soft tissue of brain such as soft palate,mandibular lymph nodes,parotid glands,subcutaneous and inter-muscular fascia as well as muscle pads was significant enhanced compared with pre-contrast.The characteristics and improvement methods of six typical MRI artifacts was discussed such as metal artifact,wraparound artifact,truncation artifacts,chemical shift artifact,motion artifacts,and spike artifact.Study third was retrospective analysis of 6 cases which involved peripheral nerve compression,joint effusion,increased intracranial pressure,maxillary osteosarcoma,syringomyelia,herniated disc,and cerebellar atrophy.Those lesions have typical MRI findings,and those images of all cases can be used for clinical diagnosis.These cases initially verified the clinical value of superconducting MRI in the diagnosis of paralysis,dysfunction,brain trauma,tumors and other diseases.In conclusion,superconducting MRI scan can obtain soft tissue images with high contrast,high resolution and high SNR.MRI Atlas of normal anatomy in each part was made.Scan parameters such as FOV,ETL,NSA,matrix,fat set technique,and receive coil can affect the quality of image.Gd-DTPA can enhance the MR signal of the soft tissue of the head.Characteristics of six typical MRI artifacts and their improvement methods were summarized.The significant value of superconducting MRI in diagnosis was preliminarily verified by cases analyzed.