Normal Transcranial Doppler (TCD) Report Template

Normal transcranial Doppler report template: MCA, ACA and PCA mean velocities by depth, Lindegaard ratio and flow direction, with vasospasm threshold notes.

EXAMINATION: Transcranial Doppler ultrasound.

CLINICAL HISTORY: [indication]

COMPARISON: [date of prior, or None available].

TECHNIQUE: Transtemporal, transorbital and suboccipital insonation of
the intracranial arteries with spectral Doppler. Temporal windows were
adequate bilaterally.

FINDINGS:
Right MCA: Mean velocity [x] cm/s at [x] mm depth. Normal waveform and
flow direction.
Left MCA: Mean velocity [x] cm/s at [x] mm depth. Normal waveform and
flow direction.
Right ACA: Mean velocity [x] cm/s. Normal flow direction.
Left ACA: Mean velocity [x] cm/s. Normal flow direction.
Right PCA: Mean velocity [x] cm/s. Normal flow direction.
Left PCA: Mean velocity [x] cm/s. Normal flow direction.
Vertebrobasilar system: Basilar mean velocity [x] cm/s. Normal
waveforms.
Lindegaard ratio: [x] on the right, [x] on the left.
Extracranial ICA: Mean velocity [x] cm/s bilaterally.

IMPRESSION:
1. Normal intracranial velocities bilaterally. No evidence of
vasospasm.

Dictation notes

• Elevated MCA velocity with a Lindegaard ratio above 3 is vasospasm; the same velocity with a ratio below 3 is hyperemia — the ratio, not the velocity, makes the call.
• State window adequacy explicitly; an absent temporal window is a limitation the ICU team must know about, not a silent omission.
• Trend matters more than a single number in the SAH patient — compare each vessel with the prior study in the impression.

Frequently asked questions

What does a transcranial Doppler report include?

A TCD report gives the mean velocity, insonation depth, waveform and flow direction for each middle, anterior and posterior cerebral artery, the vertebrobasilar system, and the extracranial internal carotid arteries, plus the Lindegaard ratio for each side. Window adequacy is stated explicitly. A normal impression reads 'Normal intracranial velocities bilaterally. No evidence of vasospasm.'

How does the Lindegaard ratio distinguish vasospasm from hyperemia?

The Lindegaard ratio divides the middle cerebral artery mean velocity by the ipsilateral extracranial internal carotid velocity. Elevated MCA velocity with a ratio above 3 indicates vasospasm — focal narrowing accelerating flow — while the same velocity with a ratio below 3 indicates hyperemia, where flow is globally increased. The ratio, not the absolute velocity, makes the call, which is why both measurements belong in the report.

Why must TCD reports state acoustic window adequacy?

An absent or poor temporal window means the anterior circulation on that side was not assessed, and the ICU team following a subarachnoid hemorrhage patient must know that rather than infer normality from silence. Stating window adequacy also frames the serial examinations that matter most in vasospasm surveillance: the trend in each vessel's velocity against the prior study is more informative than any single number, and the impression should compare them.

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