Diffusion-Weighted MRI of the Liver

Targeted CE per ARRT’s Discipline, Category, and Subcategory classification for enrollments starting after February 8, 2023:
[Note: Discipline-specific Targeted CE credits may be less than the total Category A credits approved for this course.]

Magnetic Resonance Imaging: 3.25
Image Production: 2.25
Sequence Parameters and Options: 0.50
Data Acquisition, Processing, and Storage: 1.75
Procedures: 1.00
Body: 1.00

Registered Radiologist Assistant: 1.00
Procedures: 1.00
Abdominal Section: 1.00

Outline

1. Introduction
2. Principles of Diffusion-weighted Imaging of the Liver
3. Liver Diffusion Imaging Acquisition, Optimization, and Display
   1. DW MR Imaging Acquisition Techniques
   2. Choice of b Values and Sequence Optimization
   3. Image Display and Processing
   4. ADC Reproducibility
   5. Current Applications of Liver DW MR Imaging: Liver Lesion Detection
   6. Current Applications of Liver DW MR Imaging: Liver Lesion Characterization
   7. DW MR Imaging in Assessment of Tumor Response to Treatment
   8. Diagnosis of Liver Fibrosis and Cirrhosis with DW MR Imaging
   9. Estimation of Tumor Perfusion with IVIM DW MR Imaging
4. Limitations of DW MR Imaging Technique in the Liver
5. Future Directions
6. Conclusions

Objectives

Upon completion of this course, students will:

1. understand how to incorporate DW MR imaging into existing protocols
2. identify why MR is useful in evaluating patients with liver disease
3. understand the foundations of the principles of DW MR imaging
4. understand the process of diffusion
5. understand how DW MR image contrast is calculated
6. identify the difference between restricted and relatively free apparent diffusion
7. understand how diffusion is observed and measured
8. understand the different diffusion directions measured
9. understand the role of the b value in DW MR imaging of the liver
10. identify the number of b values needed to quantify ADC values
11. understand the information obtained from ROI quantification
12. be familiar with the IVIM phenomenon
13. understand advantages of specific DW MR imaging techniques
14. understand the challenges of specific DW MR imaging techniques
15. understand trade-offs of sequence optimization
16. be familiar with the useful range of b values used in DW MR liver imaging
17. understand the importance of utilizing low b values
18. understand the importance of utilizing high b values
19. identify trace images
20. understand the importance of qualitative visual assessment in detecting liver lesions
21. understand T2 shine-through
22. identify lesions based on visual assessment of b value images and ADC maps
23. understand quantitative assessment of ADC maps
24. be familiar with the unit of measurement expressing the ADC of tissue
25. understand reasons for variation in the ADC measurements
26. understand why lesion detection is improved with DW MR imaging vs T2W imaging
27. understand the benefit of DW MR imaging in patients with impaired renal function
28. understand visual comparisons in liver lesion characterization
29. be familiar with the accuracy of visual assessment in liver lesion characterization
30. understand the role of published ADC values in identifying liver lesions
31. be familiar with the therapies that DW MR imaging can measure tumor response to treament
32. identify an effective treatment response
33. identify the potential predictive value of the DW MR imaging technique
34. understand how cirrhosis is diagnosed with DW MR imaing
35. understand the changes in diffusion in patients with liver fibrosis
36. understand which b value contributes perfusion information
37. understand limitations of DW MR imaging techniques in the liver
38. understand the key solution to improve image quality
39. be familiar with the potential benefits of DW MR imaging at high field
40. understand how to avoid limitations of the DW MR technique