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Kenichi Ido - One of the best experts on this subject based on the ideXlab platform.
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Bile Duct Wall thickness measured by intraDuctal US in patients who have not undergone previous biliary drainage.
Gastrointestinal endoscopy, 1999Co-Authors: Kiichi Tamada, Takeshi Tomiyama, Akira Oohashi, Shinichi Wada, Takashi Nishizono, Shigeo Tano, Toshiyuki Aizawa, Takamitsu Miyata, Yukihiro Satoh, Kenichi IdoAbstract:Background: We investigated the bile Duct Wall thickness measured on intraDuctal US in patients who had not undergone biliary drainage, with special attention to the influence of cancer at the distal bile Duct, bile Duct stones, obstructive jaundice, longitudinal cancer extension, and primary sclerosing cholangitis on Wall thickness. Methods: The study included 183 patients. Patients who had undergone previous biliary drainage were excluded. IntraDuctal US was performed by the transpapillary route with use of a thin-caliber ultrasonic probe (2.0 mm diameter, 20 MHz frequency). The bile Duct Wall thickness (width of the inside hypoechoic layer) was retrospectively measured on US images. Results: Bile Duct Wall thicknesses of the common hepatic Duct for the control group (n = 95), cancer at the distal bile Duct group (n = 9), bile Duct stone group (n = 56), and obstructive jaundice group (n = 17) were 0.6 ± 0.3 mm (mean ± SD), 0.8 ± 0.5 mm, 0.8 ± 0.6 mm, and 0.8 ± 0.5 mm, respectively. No significant differences (p > 0.05) were found between them. However, Wall thickness for the cancer extension to the common hepatic Duct group (n = 4, 2.0 ± 0.4 mm) and sclerosing cholangitis group (n = 2, 2.5 ± 0.4 mm) were significantly greater than in the other groups (p < 0.005). Conclusions: In patients who have not undergone previous biliary drainage, the bile Duct Wall thickness was not thicker in patients with obstructive jaundice. However, the Duct Wall was significantly thicker in patients with either longitudinal cancer extension or primary sclerosing cholangitis compared with that of other groups. (Gastrointest Endosc 1999;48:199-203)
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Influence of biliary drainage catheter on bile Duct Wall thickness as measured by intraDuctal ultrasonography
Gastrointestinal endoscopy, 1998Co-Authors: Kiichi Tamada, Takeshi Tomiyama, Masahiko Ichiyama, Akira Oohashi, Shinichi Wada, Takashi Nishizono, Shigeo Tano, Toshiyuki Aizawa, Kenichi Ido, Ken KimuraAbstract:Abstract Objective : To determine the influence of biliary drainage catheter placement on bile Duct Wall thickness, we performed intraDuctal ultrasonography (IDUS) in patients before and after biliary drainage. Methods : Patients underwent IDUS before and after either short-term (n = 9, 6 to 8 days) or long-term (n = 9, 14 to 35 days) biliary drainage using a thin (2.0 mm diameter), 20 MHz probe inserted by means of a transpapillary route or a percutaneous tract. The bile Duct Wall thickness (mean ± standard deviation) was retrospectively measured at the upper portion of the common hepatic Duct. Results : The bile Duct Wall thickness increased from 0.8 ± 0.4 mm (predrainage) to 2.0 ± 1.6 mm (post-drainage) in the long-term group ( p Conclusions : The bile Duct Wall thickness as measured on IDUS appears to be increased after placement of biliary drainage catheters. (Gastrointest Endosc 1998;47:28-32.)
Kiichi Tamada - One of the best experts on this subject based on the ideXlab platform.
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Bile Duct Wall thickness measured by intraDuctal US in patients who have not undergone previous biliary drainage.
Gastrointestinal endoscopy, 1999Co-Authors: Kiichi Tamada, Takeshi Tomiyama, Akira Oohashi, Shinichi Wada, Takashi Nishizono, Shigeo Tano, Toshiyuki Aizawa, Takamitsu Miyata, Yukihiro Satoh, Kenichi IdoAbstract:Background: We investigated the bile Duct Wall thickness measured on intraDuctal US in patients who had not undergone biliary drainage, with special attention to the influence of cancer at the distal bile Duct, bile Duct stones, obstructive jaundice, longitudinal cancer extension, and primary sclerosing cholangitis on Wall thickness. Methods: The study included 183 patients. Patients who had undergone previous biliary drainage were excluded. IntraDuctal US was performed by the transpapillary route with use of a thin-caliber ultrasonic probe (2.0 mm diameter, 20 MHz frequency). The bile Duct Wall thickness (width of the inside hypoechoic layer) was retrospectively measured on US images. Results: Bile Duct Wall thicknesses of the common hepatic Duct for the control group (n = 95), cancer at the distal bile Duct group (n = 9), bile Duct stone group (n = 56), and obstructive jaundice group (n = 17) were 0.6 ± 0.3 mm (mean ± SD), 0.8 ± 0.5 mm, 0.8 ± 0.6 mm, and 0.8 ± 0.5 mm, respectively. No significant differences (p > 0.05) were found between them. However, Wall thickness for the cancer extension to the common hepatic Duct group (n = 4, 2.0 ± 0.4 mm) and sclerosing cholangitis group (n = 2, 2.5 ± 0.4 mm) were significantly greater than in the other groups (p < 0.005). Conclusions: In patients who have not undergone previous biliary drainage, the bile Duct Wall thickness was not thicker in patients with obstructive jaundice. However, the Duct Wall was significantly thicker in patients with either longitudinal cancer extension or primary sclerosing cholangitis compared with that of other groups. (Gastrointest Endosc 1999;48:199-203)
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Influence of biliary drainage catheter on bile Duct Wall thickness as measured by intraDuctal ultrasonography
Gastrointestinal endoscopy, 1998Co-Authors: Kiichi Tamada, Takeshi Tomiyama, Masahiko Ichiyama, Akira Oohashi, Shinichi Wada, Takashi Nishizono, Shigeo Tano, Toshiyuki Aizawa, Kenichi Ido, Ken KimuraAbstract:Abstract Objective : To determine the influence of biliary drainage catheter placement on bile Duct Wall thickness, we performed intraDuctal ultrasonography (IDUS) in patients before and after biliary drainage. Methods : Patients underwent IDUS before and after either short-term (n = 9, 6 to 8 days) or long-term (n = 9, 14 to 35 days) biliary drainage using a thin (2.0 mm diameter), 20 MHz probe inserted by means of a transpapillary route or a percutaneous tract. The bile Duct Wall thickness (mean ± standard deviation) was retrospectively measured at the upper portion of the common hepatic Duct. Results : The bile Duct Wall thickness increased from 0.8 ± 0.4 mm (predrainage) to 2.0 ± 1.6 mm (post-drainage) in the long-term group ( p Conclusions : The bile Duct Wall thickness as measured on IDUS appears to be increased after placement of biliary drainage catheters. (Gastrointest Endosc 1998;47:28-32.)
Anna Snakowska - One of the best experts on this subject based on the ideXlab platform.
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Diffraction of sound waves at the opening of a soft cylindrical Duct
The European Physical Journal Special Topics, 2008Co-Authors: Anna SnakowskaAbstract:The paper presents analytical description of diffraction phenomena at the opening of an acoustically soft cylindrical Duct and solution of the wave equation with adequate boundary condition imposed by the Duct Wall. Mathematical tools which were applied are the Green's first theorem and the Green's free-space function in cylindrical co-ordinates. As a result, the velocity potential was expressed as a surface integral, containing discontinuity of the normal component of the particle velocity on the Duct Wall. The solution of the problem consists in calculating this discontinuity by means of the Wiener-Hopf technique and results in formulas for the velocity potential inside and outside the Duct.
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SOUND WAVES DIFFRACTION PHENOMENA AT OPENING OF SOFT CYLINDRICAL DuctS
Molecular and Quantum Acoustics, 2007Co-Authors: Anna SnakowskaAbstract:The paper presents analytical description of diffraction phenomena at the opening of an acoustically soft cylindrical Duct and solution of the wave equation with adequate boundary condition imposed by the Duct Wall. Mathematical tools which were applied are the Green’s first theorem and the Green’s free-space function in cylindrical co-ordinates. As a result, the velocity potential was expressed as a surface integral, containing discontinuity of the normal component of the particle velocity on the Duct Wall. The solution of the problem consists in calculating this discontinuity by means of the Wiener-Hopf technique and results in formulas for the velocity potential inside and outside the Duct.
Jie Ren - One of the best experts on this subject based on the ideXlab platform.
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Application value of ultrasonography in biliary complications after liver transplantation
2015Co-Authors: Yong-jiang Mao, Rongqin Zheng, Jie Zeng, Jie RenAbstract:Objective To investigate the application value of ultrasonography in biliary complications after liver transplantation. Methods Clinical data of 52 patients who developed biliary complications after liver transplantation and treated in the Third Affiliated Hospital of Sun Yat-sen University between October 2003 and January 2010 were retrospectively studied. The informed consents of all patients were obtained and the local ethical committee approval had been received. Among the 52 patients, 49 were males and 3 were females with the average age of (48±18) years old. Liver grafts were thoroughly examined with color Doppler ultrasound (CDUS). The observation indexes included dilation of bile Duct, thickening of bile Duct Wall, echo enhancement of bile Duct Wall, narrowing of hilar biliary Duct lumen, intraDuctal echo and acoustic shadow as well as intrahepatic and extrahepatic local dark areas. Results The major ultrasonographic manifestations of biliary complications after liver transplantation were 96% (50/52) dilation of bile Duct, 75% (39/52) echo enhancement of bile Duct Wall, 62% (32/52) thickening of bile Duct Wall, 54% (28/52) narrowing of biliary Duct lumen and 37% (19/52) formation of intrahepatic biliary sludge and biliary calculus. The direct ultrasonographic sign of biliary stricture was the narrowing of biliary Duct lumen and the indirect signs included dilation of bile Duct, thickening of bile Duct Wall and echo enhancement of bile Duct Wall. Formation of intrahepatic biliary sludge and biliary calculus manifested a local or diffuse acoustic shadow behind the medium or high echo mass. Bile leakage manifested a local dark space in portal hepatis or subhepatic space. Biloma manifested a dispersed intrahepatic patchy high-echo area or low-echo dark area. Conclusions Biliary complications after liver transplantation have typical ultrasonographic signs. Ultrasonography may provide diagnostic evidence for biliary complications after liver transplantation. Key words: Liver transplantation; Postoperative complications; Ultrasonography, Doppler, color; Biliary tract diseases
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Evaluation of ultrasonography in diagnosis of biliary stricture after liver transplantation
2014Co-Authors: Yong-jiang Mao, Mei Liao, Yan Lyu, Jie Zeng, Jie RenAbstract:Objective To assess the value of ultrasonography in the diagnosis of biliary stricture after liver transplantation (LT). Methods A total of 127 patients after LT in Liver Transplantation Center, the Third Affiliated Hospital of Sun Yat-sen University from January 2004 to March 2011 were included in this prospective study [116 males, 11 females; average age: (49±8) years old]. The informed consents of all patients were obtained and the ethical committee approval was received. Firstly, color Doppler ultrasound examination was performed in the patients. The ultrasound images were blindedly analyzed by two senior sonographers. The diagnostic indicators of biliary stricture ofter LT were hilar bile Duct lumen narrowing, dilatation of bile Duct, bile Duct Wall thickening, echo enhancement of bile Duct Wall. The endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC) results were taken as the gold standard for diagnosing biliary stricture after LT. The diagnostic sensitivity and specificity of the 4 single indicators and combined indicators were observed. Results The diagnostic sensitivity and specificity of the 4 single indicators hilar bile Duct lumen narrowing, dilatation of bile Duct, bile Duct Wall thickening, echo enhancement of bile Duct Wall were 0.68 and 1.00, 1.00 and 0.73, 0.71 and 0.87, 0.80 and 0.70. The diagnostic sensitivity and specificity of combined indicators dilatation of bile Duct + bile Duct Wall thickening or echo enhancement of bile Duct Wall reached 0.80 both. Conclusions Ultrasonography is useful in the diagnosis of biliary stricture after LT. Hilar bile Duct lumen narrowing can be used as a direct indicator in the diagnosis of biliary stricture after LT. And the combined indicators dilatation of bile Duct + bile Duct Wall thickening or echo enhancement of bile Duct Wall have higher reference value. Key words: Liver transplantation; Postoperative complications; Biliary stricture; Ultrasonography
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Clinical study on diagnosis and prognosis assessment of ischemic-type biliary lesion with contrast-enhanced ultrasound
Chinese Journal of Ultrasonography, 2013Co-Authors: Jie Ren, Mei Liao, Yan L, Jun-yan Cao, Bowen Zheng, Ge Tong, Rongqin ZhengAbstract:Objective To evaluate the value of contrast-enhanced ultrasound (CEUS) in diagnosing ischemic-type biliary lesion (ITBL) and analyze the relation between the enhancement patterns of bile Duct Wall of ITBL and its outcome.Methods 36 patients confirmed with ITBL (24 cases),anastomotic biliary stricture (3 cases),cholangitis (4 cases),biliarysludge (1 cases),and acute rejection (4 cases),who underwent CEUS examination,were enrolled in this study.The images were retrospectively analyzed in consensus by 2 readers.After reviewing the images,the readers were asked to make a diagnosis of ITBL.The diagnostic standard was hypo-or non-enhancement of hilar bile Duct Wall in arterial phase on CEUS.Results The diagnostic sensitivity,specificity,accuracy,positive predictive value and negative predictive value were 66.7％,83.3％,72.2％,88.9％,and 55.6％ for reader 1;62.5％,83.3％,69.4％,88.2％,and 52.6 ％ for reader 2,respectively.The interobserver agreement was good (κ =0.83).In 24 ITBL patients,the ratio of mortality or retransplantation with non enhancing hilar bile Duct Wall in arterial phase was much higher than that with enhancing hilar bile Duct Wall (non-enhancement 54.5％,hypo-enhancement 20％,hyper-or iso-enhancement 12.5％).Conclusions CEUS had diagnostic value of ITBL.Non-enhancing hilar bile Duct Wall in arterial phase on CEUS predicated the poor outcome. Key words: Ultrasonography; Microbubbles; Liver transplantation; Bile Duct diseases; Ischemia
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Enhancement patterns of hilar bile Duct Wall of ischemic-type biliary lesion on contrast-enhanced ultrasound
Chinese Journal of Ultrasonography, 2012Co-Authors: Jie Ren, Mei Liao, Yan L, Ting Zhang, Rongqin ZhengAbstract:Objective To study the enhancement patterns of hilar bile Duct Wall of ischemic-type biliary lesion (ITBL) on contrast-enhanced ultrasound (CEUS).Methods Eighteen healthy subjects,18 orthotropic liver transplantation (OLT) recipients without complications,and 36 patients,which were subdivided into 2 groups according to the final diagnosis:patients with (n =24) and without (n =12)ITBL,were enrolled in this study.The patients without ITBL had anastomotic biliary stricture (n =3),cholangitis (n =4),biliary sludge (n =1),and acute rejection (n =4),respectively.The images of baseline sonography and CEUS were retrospectively analyzed in consensus by 2 readers.The enhancement time and level of hilar bile Duct Wall,hepatic artery and liver parenchyma were recorded.Results Hilar bile Duct Wall became enhancing earlier than liver parenchyma in all of 4 groups.During arterial phase,hyper-or isoenhancing bile Duct Walls were present in most cases in the groups of healthy subjects,OLT recipients without complications and patients without ITBL.However,non-or hypo-enhancement of hilar bile Duct Wall were present in 16 (66.7％) ITBL patients,which is different from the other groups (P ＜0.05).Conclusions The main features of ITBL differing from the other groups were non-or hypo-enhancement of hilar bile Duct Wall in arterial phase.It may be a diagnostic index to apply in detecting ITBL with CEUS. Key words: Ultrasonography ; Microbubbles ; Liver transplantation ; Biliary tract ; Ischemia
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Feasibility of evaluatingthe microcirculation of hilar bile Duct Wall of liver grafts with contrast-enhancedsonography
Chinese Journal of Ultrasonography, 2010Co-Authors: Jie Ren, Mei Liao, Ping Wang, Ren Mao, Rongqin ZhengAbstract:：Objective To investigatethe feasibility and methodology of detecting the microcirculation of hilar bile Duct Wallwith contrast-enhanced ultrasound (CEUS). Methods Sixteen patients after orthotropic livertransplantation(OLT) were studied. The dosage of contrast agent(SonoVue) was set for 2groups: 1.5 ml and 2.4 ml. Each group was composed of 8 patients. The imaging quality ofCEUS were retrospectively analyzed and divided into 3 grades: good, ordinary and bad.There were 2 patients received retransplantation. Their morphologic features of hilar bileDuct Wall in baseline ultrasound (US) and CEUS were compared with those in pathologicalexamination. Results Biliary perfusion could be displayed by CEUS continuously,real-timelyand clearly. The imaging quality was good in 8 cases(50%), ordinary in 6 cases (37. 5%)and bad in 2 cases(12. 5%). There was no significant difference between the imagingquality of 1. 5 ml and that of 2. 4 ml group ( P = 0. 78). Conclusions The imaging qualityof hilar bile Duct Wall in CEUS is good enough to detect its microcirculation. There is nosignificant difference between the imaging quality of 1. 5 ml and that of 2.4 ml group.
M. I. Nizovtsev - One of the best experts on this subject based on the ideXlab platform.
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Heat transfer in the zone of flow of a Wall counterjet
Heat Transfer Research, 1993Co-Authors: M. I. NizovtsevAbstract:Experimental results on heat transfer between a Wall counterjet and a Duct Wall in a zone of the Wall counterjet propagation are presented. The effect of the relative injection velocity on heat transfer enhancement is studied. Heat transfer between the Wall counterjet and the Duct Wall was considered by analogy with heat transfer in a boundary layer with a change of the external boundary conditions. Any analytical relation for calculating the heat transfer on the main section of a developing counterjet is obtained. Calculation by the relation proposed gives a satisfactory agreement with experimental results.
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The Flow Separation from a Duct Wall Caused by the Near-Wall Counterjet
Separated Flows and Jets, 1991Co-Authors: E.p. Volchkov, V. P. Lebedev, M. I. Nizovtsev, V. I. TerekhovAbstract:The different kinds of steps, salients, sudden contractions or expansions of the passage cross-section, the presence of bluffs, i.e. the geometrical features of the Ducts are considered to be responsible for the origin of separated flows. The flow separation from a Duct Wall may be originated also by the local jet injection from the Wall, thereat the separated flow characteristics can be simply enough controlled by the jet flow rate. In,[1, 2], the results of theoretical and experimental study of some characteristic properties of separated flows behind the section of normal injection are discussed. The present paper deals with the results of the complex experimental study of a flow in the zone of separation, recirculation and the flow reattachment to a Duct Wall when the near-Wall jet is supplied to meet the air stream.
