Doc #: 60-00118 Rev. A
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Diagnostic Exams
This section describes Diagnostic exams in general. Functions specific to Complete or Limited
exams are described in separate sections.
Diagnostic Exams are intended to be performed unilaterally with a hand-held probe.
1. Scanning controls can be adjusted to optimize the M-mode and spectrogram displays.
2.
A red “flow band” in the M-mode display indicates blood flowing toward the probe and
blue band indicates flow away from the probe.
3. Placement of the M-mode depth cursor in a flow band will display the spectrogram at a
specific point in a blood vessel. (depth)
4. Technologists skilled in performing Transcranial Doppler exams will use the M-mode,
angle of insonation, depth, waveform and sound to identify specific vessels.
5. Protocols can be used to step through vessels in a specified sequence or vessels can be
located randomly.
6. Vessels can be labeled using the vessel labelling controls.
7. Vessels can be interrogated in 1 mm depth increments.
8. An envelope will trace the spectrogram and the Maximum (Peak Systolic) and Minimum
(End Diastolic) velocities will be measured from the envelope. The Mean Velocity and
Pulsatility Index (PI) are calculated from the measurements.
9. If the signal is weak and increasing the gain does not make the envelope track the
spectrogram properly, the screen can be “Frozen” (See Scanning Controls) to remove the
envelope and manually measure the Max and Min velocities.
10. Snapshots are used to capture velocities at different depths. When a snapshot is taken,
the average Max, Min and Mean velocities, a static image of the 4 second spectrogram
and if selected, an MP4 video will all be saved. Note, screenshots display max, min, and
mean velocities at the time of the capture; therefore, are not averaged.
11. Diagnostic reports are based on selected snapshots and there is no limit to the number of
snapshots that can be taken in an exam.
WARNING
Do not exceed 10% power through the eye or foramen magnum.
