CT and MRI

1. CT and MRI

2. Computed Tomography • 1972 __________________ • X-ray tube in a tube • Rows of _________ opposite x-ray tube • Produces ___________________

3. 1st generation _________ Transmits beam then ________ Long scan times 2nd generation _________ Transmits a fan beam then _________ Faster scanning 1st and 2nd Generation

4. 3rd generation _____________ More detectors 4th generation Detectors _____________ Continuous rotating x-ray tube 3rd and 4th Generation

5. Helical/Spiral scanning • ______________technology • Tube rotation ____________ • Pt movement continuous • ______________of data • Faster scanning

6. Hounsfield UnitsCT Numbers • Can determine material based on the __________(linear attenuation coefficient) • __________ = 0 • Cortical bone = +1000 • ________= -1000

7. Multi slice • Obtaining multiple slices ____________ • Much faster scanning • 4, 16, 32, 64 slice • And More

8. Contrast • IV – _____________ same as X-ray • __________– visualizes GI track • ______– quicker visualization of Lower GI

9. MRI • 1983 1st Installed MRI. 1946 discovered. • Uses primarily • ___________ • ________________ • Good anatomical detail

10. Magnet Types • Resistive • ____________ • ________________

11. MRI (Sort of) • _______________ • Some ___________ in the magnet • Magnetic moment • Radiofrequency (RF) • ______________ • Atoms ___________ • Computer recon image

12. T1 and T2 Weighted • MRI visual contrast • T1 – ______________ • T2 – ______________ • Unless it’s blood

13. MRI IV contrast • Not like X-ray • ___________ • Metallic based • ________________than X-ray • Until recently

14. Safety • _________________________ • Carefully screen pt • __________________