Does anybody know how we should measure Doppler parameters in lymph nodes?
OBJECTIVE
To show how currently described techniques confuse interpretation of Doppler indices in lymph node characterization.


METHODS
The Doppler indices [resistivity index (RI) and pulsatility index (PI)] were obtained in 35 malignant lymph nodes by colour duplex sonography. Each node was sampled at eight different sites. Data were analysed using our own method, and methods employed in six previous studies.


RESULTS
Restistivity index values varied between 0.69 and 0.88 and PI values ranged from 1.28 to 2.34. All but two methods produced different resistance indices (P < 0.05).


CONCLUSIONS
Conflicting results are obtained analysing the same data using different methods. Standardized techniques should be agreed and employed in future studies.
Ho
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Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, N.T., Hong Kong.
Metreweli
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Ahuja
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D001783:Blood Flow Velocity; D006801:Humans; D008198:Lymph Nodes / Q000098:blood supply*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D009303:Nasopharyngeal Neoplasms; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D018615:Ultrasonography, Doppler, Color / Q000379:methods* / Q000592:standards; D014655:Vascular Resistance