| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥3,200,000 (Direct Cost: ¥3,200,000)
|
|---|
| Research Abstract |
The structural changes of bone observed in metabolic bone diseases and osteochondral dysplasias are too small to detect in radiologic images. Those are only microscopically observed on the surface of trabeculae of 0.15 mm thickness and in osteons of 0.15 mm in diameter. Recently, however, development of high threw rate gradient system and surface coils make it possible to detect such microscopic change on MR images.
Materials and Methods : We used a small surface coil specially designed for finger imaging (GE, Fig. 1) on a 1.5-T clinical MR scanner (Signa Horizon, GE). The coil is bird-cage type with a quadrature system, impedance of 50 ohm, and in accordance with the safety standard of LEC 601-1. We performed MR microscopy of the second middle phalanges of five normal volunteers and three patients with hyperparathyroidism.Field of view (FOV) was from 2 to 4 cm, matrices were 512x512, and slice thickness was 1 mm. We used gradient echo (GRASS) sequence at the beginning, and then changed to 3D GRASS sequence for better S/N ratio. The coil was placed on a plastic table of dome type set on the examine's abdomen, so that the examine did not feel discomfort during the imaging (Fig. 2).
Results : We could obtain good quality MR images, and detect the Haversian system on the MR microscopy (Fig. 3). Slightly dilatation and increase of detected number of the Haversian canal was observed in the patients with hyperparathyroidism. Image display of a narrow window width was useful to distinguish the Haversian canal from noise. In addition, detailed structure of the interphalangeal joint could be observed.
Conclusion : MR microscopy may be an useful adjunct in diagnosis of metabolic bone diseases and minimal cartilage trauma.
|
