Analysis of posterior echoes using reconstructed vertical ultrasound images.
OBJECTIVE
To evaluate the role of vertical images reconstructed using 3-D data in the analysis of posterior echoes.


METHODS
Reconstructed vertical images of US phantoms with the following artifacts were retrieved and analyzed: acoustic shadowing (clean and dirty); posterior echo enhancement (with/without lateral shadowing); and reverberation artifacts (clean and dirty).


RESULTS
For acoustic shadowing, a stone and posterior clean acoustic shadowing were imaged as an echogenic mass or an echogenic ring containing a central echo-free area. However, the stone and dirty acoustic shadowing were imaged as an echogenic mass or an echogenic mass consisting of many fine echo spots disseminated throughout the whole mass. For posterior echo enhancement, when lateral shadowing is present, the cyst and posterior echo enhancement are imaged as a round anechoic mass or a triple circle consisting of a thin anechoic outer rim, an echogenic ring, and an anechoic center. However, when lateral shadowing is absent, they are imaged as a round anechoic mass or a double circle consisting of an echogenic outer rim and an anechoic center. For clean reverberation artifacts and dirty reverberation artifacts, vertical images of clean reverberation artifacts consist of either a homogeneous echogenic area or an absent signal. However, vertical images of dirty reverberation artifacts consist of a homogeneous echogenic area and an area consisting of fine echo spots.


CONCLUSIONS
Our study suggests that reconstructed, previously unattainable, vertical plane images help us better understand the mode of posterior echoes.
First Department of Internal Medicine, Akita University School of Medicine, Akita, Japan.
Michiko
M
Sato
Center of Diagnostic Ultrasound, Akita Red Cross Hospital, 222-1 Saruta Kamikitade, Akita, 010-1495, Japan. ishida@archosp-1998.com.
Hideaki
H
Ishida
First Department of Internal Medicine, Akita University School of Medicine, Akita, Japan.
Kei
K
Konno
Center of Diagnostic Ultrasound, Akita Red Cross Hospital, 222-1 Saruta Kamikitade, Akita, 010-1495, Japan.
Tomoya
T
Komatsuda
Center of Diagnostic Ultrasound, Akita Red Cross Hospital, 222-1 Saruta Kamikitade, Akita, 010-1495, Japan.
Kayoko
K
Furukawa
Center of Diagnostic Ultrasound, Akita Red Cross Hospital, 222-1 Saruta Kamikitade, Akita, 010-1495, Japan.
Mamiko
M
Yamada
Center of Diagnostic Ultrasound, Akita Red Cross Hospital, 222-1 Saruta Kamikitade, Akita, 010-1495, Japan.
Hitoshi
H
Yagisawa
First Department of Internal Medicine, Akita University School of Medicine, Akita, Japan.
Yasuo
Y
Yoshida
First Department of Internal Medicine, Akita University School of Medicine, Akita, Japan.
Sumio
S
Watanabe
3-D ultrasound; artifact; posterior echo; reverberation