Equipment used for TCD and TCDI is separate and distinct. The majority of velocity reference standards for intracranial studies were obtained at a zero degree angle with non-imaging TCD equipment. Decreased velocities and inferior penetration are reported when comparing TCDI to TCD studies.

• Transcranial Doppler Ultrasound Equipment (TCD)
  • Utilizes a single crystal 1.5-2.5MHz pulsed Doppler probe
  • Equipment and software specifically designed for TCD applications
    • Displays all data in real time including:
      • Sample volume, sample depth
      • Time averaged maximum mean velocity
      • Peak systolic velocity/end diastolic velocity
      • Acceleration time
      • Pulsatility (PI) or resistive indices (RI)
      • Doppler power output and frequency
    • Direction sensitive Doppler blood flow meter
    • Bi-directional Doppler waveform display
    • Audible output and permanent recording of the spectral waveform
• Transcranial Color Duplex Imaging Equipment (TCDI)
  • Duplex imaging scanner with B-Mode, color and spectral Doppler capabilities
  • Utilizes a 1-5MHz transducer probe
    • Displays all data in real time including:
      • Sample volume, sample depth, Doppler angle
      • Time averaged maximum mean velocity
      • Peak systolic velocity /end diastolic velocity
      • Acceleration time
      • Pulsatility (PI) or resistive indices (RI)
      • Doppler power output and frequency
    • Direction sensitive Doppler blood flow meter
    • Bi-directional Doppler waveform display
    • Visual display, audible output and permanent recording of the spectral waveforms with corresponding B-Mode/Color image