|
KMID : 0361819980170030303
|
|
Journal of the Korean Society of Medical Ultrasound
1998 Volume.17 No. 3 p.303 ~ p.304
|
|
|
Limitatioin of Power Doppler US for Evaluating the Vasculature of Hyperechoic Tissue : Phantom Study and New Experience for Hemanigoma
|
|
Young Hoon Kim
Byung Ihn Choi/Tae Kyoung Kim/Ah Young Kim/Joon Koo Han
|
|
|
Abstract
|
|
|
|
The major advantage of PD over color Doppler (CD) US is thought to be due to a homogeneous background when the gain is greatly increased, whereas background noise on CD US appears as random color that obscures the true information from flow. Although PD US has been proved to demonstrate more Doppler signals than CD US, it is still uncertain as to whether all the signals displayed are due to flow. Previously we reported the findings of PD US in liver tumors including hepatic hemangiomas. We found that 75% of hemangiomas demonstrated marked PD signals diffusely distributed within the lesion ; however, it was our impression that, at times, movement of highly reflective interfaces could generates a Doppler signal that simulated flow and the majority of the PD signals within hemangiomas might be attribute to artifactual signals produced from echogenic interfaces in hemangiomas. In a case with a hyperechoic hemangioma, we could demonstrate diffuse blush of PD signals within the lesion. At a 14-month follow-up study, the echogenicity of the hemangioma was decreased as fatty infiltration of the liver progressed. With the same Doppler protocol that of as previous study(PRF of 700Hz ; wall filter of low) the amount of PD signals within the lesion obviously decreased suggesting that the PD signals were closely related with the tissue echogenicity. With our new Doppler protocol(PRF of 1000 Hz ; wall filter of medium) determined by considering the results of our experimental study, no definite PD signal was depicted within the lesion. In performing PD US, artifactual Doppler signals originated from stationary hyperechoic tissue can be confused for true signals. Our results indicate that PD scanning for evaluating vascularity of hyperechoic tissue can be limited because the distinction of true flow artifacts might be difficult.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|