CBF estimation C2P Siemens sequence from UCL.

[Óscar Peña-Nogales]

Dear all,

I'm writing because I have some doubts in regards to the CBF estimation from the 3D GRASE pcASL sequence available in Siemens scanners, and provided by C2P agreement. As you may know, this sequence is from UCL, particularly from professor D. Wang.

My question is whether you know if in order to compute the CBF in units of ml/100 g/min, we need to apply some scaling to the M0 image. As for the data I have, the M0 volume has intensities from 0 to 4095, and the CSF seems to be thresholded to that value. Label-Control images have approximately 1/3 of that intensity.

I'd appreciate your opinion if you are familiar with this sequence.

Aside from that and according to the description of the sequence, I know the labeling efficiency is of 0.8.

Best

[Sudipto Dolui]

Did you try to quantify CBF using the sequence? Are those in normal range? I used it in a study with old subjects, and used a labeling efficiency of 0.69. The M0 image was not scaled in my case.

Sudipto

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[red...@gmail.com]

You should contact UCL for this.  Our sequence is 3D BS PCASL with spiral readout and we do apply a different multiple factor to the M0 (usually 1/10).  Also, if the intensity is from 0-4095, you need to reduce the scale because 4095 already reaches the maximum of the 12bit DICOM

Ze

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