Transcription of CT - 新潟大学歯学部
1 1 2 CT CT MRI CT Computed tomography CT 1901 R ntgen (1985) 1917 Radon 1945 CT 1967 Hounsfield EMI CT 1979 Hounsfield Cormack 256 2 CT CT CT CT CT Multi-detector row CT MDCT 320 16cm 3 Generation 1 Translate/Rotate single pencil beam 2 Translate/Rotate narrow fan beam 3 Rotate/Rotate wide fan beam 4
2 Stationary/Rotate wide fan beam 5 CT Filtered back projection CT Hounsfield Unit, HU 0 1,000 CT 1,000 CT 100HU 50 80HU 200 500HU 1,500 3,000HU CT = t w w 1,000 t w Window width, WW Window level, WL 3 256 8bit 300 50 CT 100 CT 200 4,000 1,000 CT 1,000 CT 3,000 Partial volume effect Vo x e l , Vo l u m e p i x e l Pixel Field of view FOV =240 240 mm Matrix 512 512 mm mm mm3 CT CT CT 1mm mm 3D volumetric image display Surface rendering Vo l u m e r e n d e r i n g Maximum intensity projection, MIP CT Multiplanar reformation / reconstruction.
3 MPR CT 10 Artifacts 4 11 CT Cone-beam CT CBCT 1999 2001 CT CT CBCT CT X X isotropic voxel CT CT 12 CT * * * 13 CBCT 5 14 CT X CT contrast enhancement % Ca
