1. Advanced Biomedical Imaging Dr. Azza Helal A. Prof. of Medical Physics Faculty of Medicine Alexandria University Lecture 2 Overview & comparison of different imaging modalities

2. Comparison of different imaging modalities 1. Projection views 2. Ionizing radiation 3. Speed 4. Contrast resolution

3. 1. Projection views Limited visualization Plain x ray & Isotope scan Flexible imaging planes Cross-section views CT & MRI

4. Flexible imaging planes with MRI.

5. MRI angiography

6. 2. Ionizing radiation Plain x - ray, CT & isotope scan

7. 3. Speed US Fast Plain x ray CT MRI Isotope scan Slow

8. 4. Contrast Plain X Ray CT CT Physical and electron density US Transmitting & receiving high frequency sound wave Isotope scan Uptake of radioactive tracer MRI Transmitting & receiving radio- waves inside a high magnetic field (Water concentration & Magnetic properties)

9. Contrast resolution Plain x ray & CT reflect bone contrast MRI reflects soft tissue contrast

10. Assignments One student will be selected for assignment One student will be selected for assignment

11. Suggested Readings David Sutton’s Radiology David Sutton’s Radiology Physics for medical imaging by RF Fare & PJ Allisy-Roberts. Physics for medical imaging by RF Fare & PJ Allisy-Roberts.

12. Questions 1. Mention the advantages of MRI over CT? 2. Enumerate the imaging modalities that use ionising radiation?