Acceleration motion compensation DWI for measuring intraventricular temperature
Shuhei Shibukawa1,2, Toshiaki Miyati2, Naoki Ohno2, Tetsu NIwa3, Yutaka Imai3, Tetsuo Ogino4, and Isao Muro1

1Depertment of Radiology, Tokai university hospital, Isehara, Japan, 2Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan, 3Depertment of Radiology, Tokai University School of Medicine, Isehara, Japan, 4Healthcare, Philips Electronics Japan Ltd., Tokyo, Japan

Synopsis

Although it has been reported a method for monitoring the intraventricular cerebrospinal fluid (CSF) temperature calculated from the DWI, this method was affected by the CSF pulsation. We proposed the acceleration-motion compensation DWI (aMC-DWI) to the determination of the intraventricular temperature to improve that accuracy and precision. Compared with conventional DWI, measurement of intraventricular temperature using aMC-DWI was accuracy even in ventricles with high flow, e.g., third ventricle, fourth ventricle. These results suggested that aMC-DWI is a suitable method for analyzing the intraventricular temperature.

INTRODUCTION

It has been reported a method for monitoring the intraventricular cerebrospinal fluid (CSF) temperature calculated from the diffusion weighted image (DWI).1 Since this method was affected by the CSF pulsation, Wetscherek et al2 reported usefulness of motion compensated diffusion gradients. However, the CSF pulsation includes accelerating flow. Therefore, we applied the acceleration-motion compensation DWI to the determination of the intraventricular temperature to improve that accuracy and precision´╝Ä

METHODS

At a 3.0 T MR system (Achieva R2; Philips Healthcare, Best, the Netherlands), to evaluate the effect of the CSF pulsation on the intraventricular temperature using DWI, we compared among three types diffusion gradients, ie., (1) conventional DWI (c-DWI), (2) motion compensation DWI (MC-DWI), and (3) acceleration-motion compensation DWI (aMC-DWI) (Fig. 1). The uniform motion compensation was achieved by using the dual bipolar gradients, and the acceleration-motion compensation was achieved by using suitable second-moment nulling gradient waveforms. DWI images of the lateral ventricle (LV), third ventricle (TV), and fourth ventricle (FV) were obtained in eight healthy volunteers. With two-dimensional single-shot echo-planar imaging (EPI), the imaging parameters were set at TR, 6000 ms; TE, 90 ms; flip angle, 90 degrees; field of view, 220 × 220 mm2; matrix,192 × 192; slice thickness, 3.0 mm, number of slices, 30; EPI factor, 35; sensitivity encoding factor, 3; and b-value, 0 and 1000 s/mm2. Diffusion coefficient was calculated from the signal intensity of DWI in each ventricle, and then the intraventricular temperature was analyzed. The intraventricular temperature for each ventricle was assessed using Friedman test. Moreover, CSF flow velocities in ventricles were determined with PPU-synchronized phase-contrast cine MRI. We also measured body temperature in the axilla to specify the normal brain temperature range, ie., brain temperature was 1.8 degrees C higher3 or 0.8 degrees C lower4 than body temperature in healthy volunteers.

RESULTS and DISCUSSION

Examples of intraventricular temperature maps is shown in Figure 2. With c-DWI, the intraventricular temperatures in TV and FV were significantly higher than that in LV (Fig. 3). However, with the other methods, there was no significant difference in the intraventricular temperature in each ventricle. The intraventricular temperature using c-DWI was affected by the CSF flow velocity, ie., 0.25±0.15 cm/s in LV, 1.5±0.55 cm/s in TV, and 0.50±0.20 cm/s in FV obtained from the PPU-synchronized phase-contrast cine MRI. Moreover, aMC-DWI provided the least outliers for normal brain temperature range (Table 1), indicating that aMC-DWI method is the most suitable for analyzing the intraventricular temperature using DWI.

CONCLUSION

The aMC-DWI makes it possible to accurately and precisely analyze the intraventricular temperature without the influence of CSF pulsation than c-DWI and MC-DWI.

Acknowledgements

No acknowledgement found.

References

1. Kozak LR et al. Acta Paediatr. 2010;99(2):237-43.

2. Wetscherek A et al. Magn Reson Med. 2015;74(2):410-9.

3. Childs C et al. Magn Reson Med. 2007;57(1):59-66.

4. Covaciu L et al. J Magn Reson Imaging. 2010;31(4):807-14.

Figures

Fig. 1 Diffusion gradients in this study. (a) Conventional DWI (c-DWI), (b) motion compensation DWI (MC-DWI), and (c) acceleration motion compensation DWI (aMC-DWI).

Fig. 2 Examples of intraventricular temperature maps in healthy volunteer calculated from (a) c-DWI, (b) MC-DWI, (c) aMC-DWI. (d) DWI with b=0.

Fig. 3 Comparison of intraventricular temperature among DWI methods in each region. Asterisks indicate significant difference (P < 0.05).

Table 1 Mean intraventricular temperature and the number of outliers.



Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)
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