Mein-Kai Gueng

Adenocarcinoma arising from colonic duplication cyst with metastasis to omentum: A case report

Gastrointestinal tract duplications are uncommon congenital abnormalities. Carcinoma arising from duplication cyst is extremely rare, not to mention metastasis to other organs. We present a case of adenocarcinoma arising from a colonic duplication cyst with invasion of the serosa and metastasis to the omentum in a 40‐year‐old man. Duplication cysts should be included in the differential diagnosis of cystic masses of the gastrointestinal tract. Because these lesions occur so infrequently, they are often not suspected until encountered intraoperatively. The specific findings and advantages of sonography are reviewed.

Color Doppler Twinkling Artifact and Clinical Use

The color Doppler twinkling artifact manifests as a rapidly changing mixture of red and blue colors behind a strongly reflecting structure. Spectral Doppler analysis of the twinkling artifact does not yield a flow spectrum. It is important to recognize this artifact because it may lead to misdiagnosis of vascular flow within a tissue. Additionally, the artifact may be considered a sonographic sign in the detection of calcifications and calculi. In this article, we review the history of the interesting phenomenon and its clinical use, as well as our personal experiences of the artifact.

Correlation Study of the Strength of the Color Doppler Twinkling Artifact with the Roughness of the Reflecting Surface and the Doppler Angles

Background The color Doppler twinkling artifact is manifested as a rapidly changing mixture of red and blue colors behind a strongly reflecting structure. The effects of the roughness of the reflecting surface and the Doppler angle on the intensity of the twinkling artifact have never been quantitatively reported before. In this study, a simple in vitro system with reproducible results was established to observe the effects of these two factors on the strength of the twinkling artifact. Materials and Methods Six different grits of water sandpapers were simultaneously scanned in a water bath with a fixed probe. In part 1, the computer calculated the pixels of color Doppler twinkling artifact behind each water sandpaper. In part 2, the signals of twinkling artifacts with different sandpaper sizes and different Doppler angles were recorded and analyzed. Results In part 1, the twinkling artifact was identified persistently and more intensely behind water sandpapers that had greater surface roughness. In part 2, different Doppler angles revealed less obvious effects on the strength of the twinkling artifacts in a certain range of angles, but would drastically decrease the intensity in the steeper angles. Conclusions We have established a simple model system with water sandpapers for the evaluation of the twinkling artifact. Our data confirmed the assumption that the roughness of the reflecting surface is directly related to the strength of the twinkling artifact. In addition, the Doppler angle affects the intensity of the artifact, but only in the steeper angles.

Color Doppler Twinkling Artifact of Calcified Cardiac Valves In Vitro: A Not Well Known Phenomenon in Echocardiography

The color Doppler twinkling artifact manifests as a rapidly changing mixture of red and blue colors behind strongly reflective structures. The twinkling artifact occurs behind diseased cardiac valves, although the phenomenon is not well described. This study sought to determine the presence of the color Doppler twinkling artifact in calcified cardiac valves in vitro using soft tissue radiography for reference. Seventeen specimens of diseased cardiac valves from patients undergoing valve replacement surgery were studied. The overall sensitivity and specificity for the detection of calcifications using the presence of the twinkling artifact were 66.7% and 81.8%, respectively. If valves with only microcalcifications or smooth calcifications were eliminated from the analysis, all (100%) of the three valves with irregular macrocalcifications exhibited the twinkling artifact. It is important to recognize this artifact because it may lead to misdiagnosis of vascular flow in echocardiography.

Soft Tissue Hemangiomas: High-resolution Grayscale and Color Doppler Ultrasonographic Features in 43 Patients

Background High-resolution ultrasonography (HRUS) is the first-line imaging modality for the assessment of soft tissue tumors. The reported HRUS features of soft tissue hemangiomas vary greatly. We reviewed 43 histologically proven soft tissue hemangiomas and describe the HRUS and color Doppler ultrasound (CDUS) features, and propose a convenient CDUS sign for diagnosis. Materials and Methods HRUS data of 43 proven soft tissue hemangiomas were included in this study. Data assessment included tumor margin, tumor echogenicity and echotexture, presence of phleboliths, fluid–fluid level in the masses, and CDUS features. In masses with weak or no color Doppler signal, color Doppler enhancing maneuver (CDEM) was applied, which was carried out using light compression on the masses or on the soft tissues adjacent to the masses. CDEM was considered positive when the color Doppler signal in a mass was more prominent and/or extensive. Results Twenty-three hemangiomas were ill-defined and 20 were well-defined. Twenty-six hemangiomas were hypoechoic and 17 were hyperechoic. Thirty-seven masses were heterogeneous in echotexture. Phleboliths were found in only nine hemangiomas. Thirty-seven hemangiomas had multiple cystic spaces and fluid–fluid levels were noted in 12. Color Doppler signals were detected in 37 hemangiomas, i.e. 33 masses had weak signals and four masses had strong signals. CDEM was positive in all 33 hemangiomas with weak color Doppler signals and was positive in four of six hemangiomas with no detectable color Doppler signal. Conclusion Typical HRUS features of a soft tissue hemangioma were an ill-defined or well-defined hypoechoic mass of heterogeneous echotexture with multiple cystic spaces. On CDUS, there may be no detectable or only weak color Doppler signals. CDEM was helpful in the diagnosis of soft tissue hemangiomas, especially in masses with no detectable color Doppler signal.

In vivo and in vitro sonographic diagnosis of an encrusted nephrostomy catheter with color doppler twinkling artifact.

Encrustation is one of the most common complications that may develop with the use of a nephrostomy catheter. We used the color Doppler twinkling artifact to detect encrustation and obstruction of a nephrostomy catheter in vivo. This was confirmed by in vitro scanning of the catheter after analyzing the radiogram. Color Doppler twinkling artifact may provide useful information on the management of nephrostomy catheters.