MRI · Neuro · PC-MRI

CSF Aqueductal Stroke Volume

Stroke volume from phase-contrast MRI aqueductal flowmetry for NPH assessment. Enter values from your workstation's numeric results table — this tool interprets values you have already measured. Decision-support only — always verify clinically.

Auto-fill from results table image

Upload a screenshot of your workstation's numeric results table (not a waveform graph). Values will be highlighted for your review.

Stroke-volume inputs (Bradley-correct)

Systolic mean flow (ml/s)

Duration of CSF systole (ms)

Diastolic (needed for full Bradley average)

Diastolic mean flow (ml/s)

Duration of CSF diastole (ms)

Direct entry (alternative)

Stroke volume — workstation value (µL)

Confirm your vendor's definition (systolic / mean / net).

Optional context parameters

Volumes

Forward/antegrade volume per cycle (µL)

Backward/retrograde volume per cycle (µL)

Heart rate (bpm)

Velocity

Peak systolic velocity (cm/s)

Systolic mean velocity (cm/s)

End-diastolic peak velocity (cm/s)

End-diastolic mean velocity (cm/s)

Flow

Peak systolic flow (ml/s)

Peak diastolic flow (ml/s)

Formulae, thresholds & reference context

Systolic volume (µL) = Systolic mean flow (ml/s) × Systolic duration (ms) ÷ 1000 × 1000

Diastolic volume (µL) = Diastolic mean flow (ml/s) × Diastolic duration (ms) ÷ 1000 × 1000

SV (Bradley) = (Systolic volume + Diastolic volume) / 2

Forward/backward SV = (Forward volume + Backward volume) / 2

Threshold: SV > 42 µL (Bradley et al., Radiology 1996) was associated with favourable VP-shunt response in NPH. Cohort was small; use as a supportive indicator, not a gate.

Reference context (not diagnostic cutoffs): Normal aqueductal SV ≈ 12–33 µL; NPH often > 60–90 µL, but ranges overlap. Values depend on ROI, VENC, gradient strength and vendor software. Net through-flow (antegrade − retrograde) is a respiratory-confounded measure distinct from the Bradley stroke volume.

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Enter systolic mean flow + duration (or a direct stroke volume) on the left to see results.