High-definition flow Doppler ultrasonographic technique to assess hepatic vasculature compared with color or power Doppler ultrasonography: preliminary experience.
OBJECTIVE
The purpose of this study was to introduce a new high-definition flow (HDF) Doppler technique and to compare its performance with those of color Doppler ultrasonography (CDU) and power Doppler ultrasonography (PDU) for assessment of hepatic vasculature in native and transplanted livers.


METHODS
High-definition flow was invented as a high-resolution bidirectional PDU technique. We obtained CDU, PDU, and HDF images of the hepatic artery (HA), portal vein (PV), and hepatic vein from 60 patients. They were divided into 2 groups: a liver transplantation group (group 1, n = 10) and a native liver group (group 2, n = 50). Two radiologists independently reviewed the cine images and graded them using a 4-point scale in terms of the clarity of the vessel margin and degree of depiction of the HA, flow filling, and flash artifacts. The degree of differentiation between the HA and PV was also evaluated. Flow directionality was recorded, and interobserver agreement was finally analyzed.


RESULTS
Moderate to almost perfect agreement was achieved between radiologists for all parameters of each ultrasonographic technique. High-definition flow was significantly superior to both CDU and PDU with respect to all analyzed items except the degree of flash artifacts (P < .05). With regard to flash artifacts, CDU was significantly better than either PDU or HDF. High-definition flow provided directional information, as did CDU.


CONCLUSIONS
The HDF technique provides better resolution for depicting hepatic vessels as well as their margins with less blooming compared with conventional Doppler ultrasonography in both native and transplanted liver. It also provides solid directional flow information. One point of concern, however, is the frequency of flash artifacts compared with that on CDU.
Kim
Se Hyung
SH
Department of Radiology, Seoul National University Hospital, Chongno-gu, Seoul 110-744, Korea.
Lee
Jeong Min
JM
Kim
Young Jun
YJ
Lee
Jae Young
JY
Han
Joon Koo
JK
Choi
Byung Ihn
BI
D000328:Adult; D000368:Aged; D005260:Female; D006499:Hepatic Artery / Q000000981:diagnostic imaging*; D006503:Hepatic Veins / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D016031:Liver Transplantation / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color / Q000379:methods*