Development of measuring system of head by MRI

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The aim of this study is to develop a measurement system on the head by magnetic resonance imaging.Volunteers were scanned by SIGNA HORIZON,1.5 tesla superconducted MR scanner. Head coil was used as a surface coil to improve the resolution of the image. As three dimensional scan, spoiled GRASS technique was applied and fast SE technique and conventional SE technique were also used as the contrast study.Image data was transferred off-line by magneto-optical disk to the work station "Advantage windows". By this work station, three dimensional measurement, including the distance and angle, was done using multi planar images.Three dimensional volume scanning with spoiled GRASS technique were available for whole head scanning and it took shorter time compared with SE technique. However, metallic artifact was huge in some cases on the image by three dimensional scanning. It was suggested fast SE technique was also useful because acquisition time was not so long and metallic artifact was no so huge.As for the reference points for the orthodontic treatment, almost points were detected on the MR image. However, because point-N (Nasion) is defined as a fusion point of the two bones, it was difficult to detect. Although there were some disadvantages in the bony tissue on MR image, soft tissue points, such as tip of the nose, lip, tongue, epiglottis, were detected. And these points must be useful and important for the cosmetic problem.