Verathon AORTASCAN AMI 9700, Operation & Maintenance Manual

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44
USING THE DEVICE
The aortic diameter measurement function provides images that may be used for diagnosis and
screening. If clinically indicated, appropriate patients should be referred for additional diagnostic
testing.
WARNING
The AortaScan system is designed to detect the fluid (blood) filled region of the abdominal
aorta only. The system cannot detect the presence of a blood clot (thrombus) and therefore may
provide a false negative result.
WARNING
The AortaScan system is an ultrasound‑based device and is subject to all limitations of this
method. If clinically indicated, appropriate patients should be referred for a diagnostic standard
(confirmatory) test, regardless of test results.
WARNING
Risk of inaccurate measurements/results. When using the instrument, be aware of the
following conditions that can decrease the accuracy of exam results:
• In some cases, the normal operating tolerances of the instrument can cause it to report a
falsely normal or abnormal measurement. For more information, see Interpret the Aortic
Measurement Results on page 51.
• Visual verification that the aorta position is fully within the scan cone on the displayed
images is important.
• A thrombus (blood clot) can complicate aortic measurements. A soft, blood‑like thrombus
may appear as part of the lumen. However, a calcified thrombus may appear as part of the
aorta’s wall, resulting in a measurement of lumen diameter that is smaller than the aorta
diameter. Accordingly, in patients where thrombus is known or suspected, other imaging
methods should be used prior to ruling out an aneurysm.
• Use care when scanning patients who have had abdominal surgery. Scar tissue, surgical
incisions, sutures, and staples can affect ultrasound transmission and accuracy.
• Ensure that the patient fasts for 12 hours prior to undergoing an aortic diameter
measurement in order to minimize the presence of bowel gas, which may obstruct proper
measurement.
• Obesity may affect ultrasound aortic diameter measurements. For more information, see
Obesity on page 54.
Accuracy is compromised if the user does not obtain an optimal, repeatable image.
WARNING