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Pulsatility Index (PI) in the Assessment of an Ovarian Neoplasm

Description

The Pulsatility Index (PI) can be determined from measurements taken using color Doppler ultrasonography. The PI is independent of the angle at which the precise angle at which the Doppler waves subtend a blood vessel. This makes it useful for when the absolute velocity and flow volume cannot be determined, such as with small, tortuous blood vessels.


 

Parameters:

(1) maximum Doppler shift frequency during the cardiac cycle

(2) minimum Doppler shift frequency during the cardiac cycle

(3) average Doppler shift frequency during the cardiac cycle

 

pulsatility index =

= ((maximum shift frequency) – (minimum shift frequency)) / (average shift frequency)

 

Interpretation:

• A PI > 1.0 indicates high pulsatility.

• A PI <= 1.0 indicates low pulsatility.

• The combination of low pulsatility and continuous end-diastolic flow may be seen in neovascularization in a malignant tumor.

• Arteries in a malignant tumor with angiogenesis may have different flow characteristics compared to a benign tumor. This can be reflected by a significantly lower pulsatility index. Malignant tumors also tend to show a low resistance index.

 

Performance:

• A negative color Doppler scan does not exclude tumor-related neovascularization.

• The PI cannot be used to diagnose a malignant ovarian tumor with certainty since there is significant overlap with benign ovarian tumors.

 


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Specialty

ICD-10