1. DWI Learning Module ACRIN 6698: Diffusion Weighted MR Imaging Biomarkers for Assessment of Breast Cancer Response to Neoadjuvant Treatment: A sub- study of the I-SPY 2 TRIAL

2. DWI Quality In this training guide, non fat-suppressed and fat-suppressed T1+Gd MRI are also provided with low b-value (b=0 s/mm 2 ) and high b- value (b=800 s/mm 2 ) DWI to illustrate how fat, non-fat parenchyma, fluids and dense lesions may look on low and high b-value DWI. Factors to be considered for evaluating DWI quality are illustrated.

3. SHIM Quality DWI requires good fat suppression and most fat suppression techniques (ChemSat, FatSat; SPIR; SPAIR) require good shim quality over the imaged breast volume. Use your most reliable shim and fat-suppression techniques when performing DWI. 10/10/2012 T.Chenevert, S.Partridge

4. Fat Suppression The technologist needs to have reasonable sense of the patient’s breast composition (amount of fatty vs. non-fat breast parenchyma) prior to performing the DWI in order to better evaluate the quality of the DWI. In ACRIN 6698, high resolution non fat- suppressed and fat-suppressed T1+Gd images ARE NOT acquired prior to diffusion scans. However, the “survey” images or, when available, prior MRI exams should be adequate to indicate the amount of fatty vs non-fatty content in a given patient. 10/10/2012 T.Chenevert, S.Partridge

5. Very Fatty Breasts Breasts composed of nearly all fatty tissue with very little non-fat parenchyma will likely yield visually low SNR diffusion weighted images. Properly-performed fat suppression, which is essential for high-quality DWI, should eliminate nearly all the available signal (see examples 2&3). The small amount of non-fat tissue and blood/fluids should remain as signal on the low b-value DWI (b=0). On the high b-value DWI (b=800), signal from these non-fat tissues also becomes suppressed, although truly dense tissue and many solid lesions will retain much of their signal. Thus, dense lesions tend to be more conspicuous on high b-value DWI. Even though fat suppression is essential, it is imperfect. Fat signal that is not fully suppressed may appear to gain relative signal strength at high b- value DWI since the non-fat tissues are losing signal as diffusion weighting increases whereas residual fat signal is unaffected by diffusion weighting. 10/10/2012 T.Chenevert, S.Partridge

6. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Good DWI Quality: Uniform FatSat & dense tissue/tumor is relatively bright on high bvalue DWI Example 1

7. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 DWI of fatty breast: Good fat suppression will eliminate nearly all signal. DWI at b=0 shows non- fat signal (eg, blood vessels and parenchyma), but DWI at high b further suppresses this non-fat signal. This can give the appearance of poor fat suppression on high b DWI. Example 2

8. DWI b=0 DWI b=800 DWI of fatty breast: Expect low SNR since good fat suppression should eliminate nearly all signal. DWI at b=0 shows remaining non-fat signal (eg, blood vessels and little parenchyma), but DWI at high b further suppresses this non-fat signal. Signal from dense tissue/lesions should remain. Example 3 Not Available

9. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Acceptable DWI Quality: Uniform FatSat. On high b DWI, expect lower SNR and an “apparent increase” in fat signal due to DWI suppression of water signal. Example 4

10. NonFatSat T1 FatSat T1 DWI b=0 DWI b=800 Poor Shim = Poor FatSat = Poor Quality DWI: Unsuppressed fat signal due to poor shim is shifted by many pixels along the phase-encoding/fold-over direction and may obscure lesions. Breast distortion also increases with poor shim. Use your most reliable shim & fat-suppression techniques. Example 5

11. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Good DWI Quality: Uniform FatSat, low distortion. Dense tissue/lesion may appear relatively brighter on high b DWI. Example 6

12. FatSat T1 DWI b=0 DWI b=800 Good FatSat but low/moderate DWI SNR: if possible, increase averages but keep DWI scantime to ~5mins. Example 7 Not Available

13. Appendix Additional DWI case examples

14. DWI b=0 DWI b=800 Low to Moderate DWI SNR: if possible, increase averages but keep DWI scantime to ~5mins Example 8 Not Available

15. NonFatSat T1DWI b=0 DWI b=800 Acceptable DWI Quality Example 9 Not Available

16. DWI b=0 DWI b=800 Low DWI Quality: Non uniform FatSat may be obscuring lesion/parenchyma Example 10 Not Available

17. DWI b=0 DWI b=800 Moderate Quality DWI: Unsuppressed fat and/or parallel imaging artifact obscures lesion of interest. Example 11 Not Available

18. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Acceptable Quality DWI: Bright fluid on b=0 DWI is suppressed on high b DWI. Fat signal may appear relatively brighter on high b DWI. DWI often exhibit spatial distortion. Example 12

19. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Acceptable Quality DWI Example 13

20. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Acceptable to Good DWI Quality Example 14

21. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Acceptable to Good DWI Quality Example 15

22. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Good Quality DWI Example 16

23. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Good Quality DWI Example 17

24. DWI b=0 DWI b=800 Acceptable Quality DWI Example 18 Not Available

25. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Acceptable DWI Quality Example 19

26. NonFatSat T1 FatSat T1+Gd DWI b=0 DWI b=800 Acceptable DWI Quality Example 20

27. Diffusion Weighted Image (DWI) Quality In this training guide, non fat-suppressed and fat-suppressed T1+Gd MRI are also provided with low b-value (b=0 s/mm 2) and high b-value (b=800 s/mm 2 ) DWI to illustrate how fat, non-fat parenchyma, fluids and dense lesions may look on low and high b-value DWI. 1) FAT: The technologist needs to have reasonable sense of the patient’s breast composition (amount of fatty vs. non-fat breast parenchyma) prior to performing the DWI in order to better evaluate the quality of the DWI. In ACRIN 6698, high resolution non fat-suppressed and fat-suppressed T1+Gd images ARE NOT acquired prior to diffusion scans. However, the “survey” images or, when available, prior MRI exams should be adequate to indicate the amount of fatty vs non-fatty content in a given patient. 2) VERY FATTY BREASTS: Breasts composed of nearly all fatty tissue with very little non-fat parenchyma will likely yield visually low SNR diffusion weighted images. Properly-performed fat suppression, which is essential for high-quality DWI, should eliminate nearly all the available signal (see examples 2&3). The small amount of non-fat tissue and blood/fluids should remain as signal on the low b-value DWI (b=0). On the high b-value DWI (b=800), signal from these non-fat tissues also becomes suppressed, although truly dense tissue and many solid lesions will retain much of their signal. Thus, dense lesions tend to be more conspicuous on high b-value DWI. Even though fat suppression is essential, it is imperfect. Fat signal that is not fully suppressed may appear to gain relative signal strength at high b-value DWI since the non-fat tissues are losing signal as diffusion weighting increases whereas residual fat signal is unaffected by diffusion weighting. 3) SHIM QUALITY: DWI requires good fat suppression and most fat suppression techniques (ChemSat, FatSat; SPIR; SPAIR) require good shim quality over the imaged breast volume. Use your most reliable shim and fat-suppression techniques when performing DWI. Breast_DWI_TrainingSet TLChenevert Apr, 2012