User's Manual

Important safety considerations
Vscan Extend – User Manual 2-19
5721203-100 Rev. 13
System controls affecting acoustic output
The operator controls that directly affect the acoustic output are
discussed in the Acoustic Output Data Tables (See ‘Acoustic
Output Reporting Tables’ on page 7-3 for more information.).
These tables show the highest possible acoustic intensity for a
given mode, obtainable only when the maximum combination of
control settings is selected. Most settings result in a much lower
output. It is important to note the following:
• The duration of an ultrasound examination is as important
as the acoustic output, since patient exposure to output is
directly related to the exposure time.
• Controls can help to reduce patient exposure, even though it
may not directly affect acoustic output.
The British Medical Ultrasound Society has suggested some
maximum scanning times relative to displayed TI as follows:
Table 2-5: Maximum scanning times
Obstetric scanning
General Abdominal, *Peripheral
Vascular, Adult cephalic,
Musculoskeletal, cardiac and other
scanning
TI time TI time Note
0.0–0.7 Unlimited 0.0–1.0 Unlimited Monitor TI
0.7–1.0 < 60 min 1.0–1.5 < 120 min
1.0–1.5 < 30 min 1.5–2.0 < 60 min
1.5–2.0 < 15 min 2.0–2.5 < 15 min
2.0–2.5 < 4 min 2.5–3.0 < 4 min
2.5–3.0 < 1 min
*Peripheral vascular is applicable for only dual probe
References
• The British Medical Ultrasound Society. Guidelines for the safe use of diagnostic ultrasound equipment.
• American Institute of Ultrasound in Medicine Consensus Report on Potential Bioeffects of Diagnostic
Ultrasound.