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 al
2 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．
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/mm
2.
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 higher
3 or 0.8 degrees C lower
4 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
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al. J
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