ICHNO-ECHNO 2022 - Abstract Book

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ICHNO-ECHNO 2022

Figure 1: Signal intensity versus acquisition number for line profiles (1.6x1.6 mm pixel size). Movement artefact seen starting at acquisition 17. Oxygen induced T 1 CSF changes were assessed as an example of healthy tissue response (Table 1). For DIXON scans, mean CSF DT 1 is -482ms (range -88ms to -835ms). Figure 1 shows an example T 1 change map for tumour regions illustrating heterogeneity of oxygenation.

CSF DT 1 Interval)

(ms) (95% Confidence

Paired t-test p- value

Participant CSF Initial T 1 (ms) Mean (stdev)

1

4392 (127)

-696 (-771 to -621)

<0.001

Withdrawn due to difference in image parameters

2

3 4 5 6 7 8

4407 (91) 3194 (66) 5192 (227) 2169 (64) 3681 (133) 2278 (192)

-835 (-946 to -724) -386 (-439 to -333) -694 (-890 to -498) -289 (-338 to -240) -386 (-440 to -332) -88 (-146 to -30)

<0.001 <0.001 <0.001 <0.001 <0.001 0.0032

Table 1: CSF T 1 & DT 1 times from pre and post oxygen DIXON scans.

Figure 2: Example T1 ratio maps. Blue = decreasing T1 (normoxic), white/red = no change/increasing T1 (hypoxic or non- perfused). Oxygen delivery is critical due to the small signal change induced by oxygen. Practical obstacles encountered related to mask fitting, coil placement and positioning of tubing.

Conclusion