Objective: Computerized tomography (CT) plays an important role in the diagnosis of diseases of biliary tract. Recently, three dimensions (3D) spiral CT imaging has been used in surgical diseases gradually. This study...Objective: Computerized tomography (CT) plays an important role in the diagnosis of diseases of biliary tract. Recently, three dimensions (3D) spiral CT imaging has been used in surgical diseases gradually. This study was designed to evaluate the diagnostic value of 3D spiral CT imaging of cholangiopancreatic ducts on obstructive jaundice. Methods: Thirty patients with obstructive jaundice had received B-mode ultrasonography, CT, percutaneous transhepatic cholangiography (PTC) or endoscopic retrograde cholangiopancreatography (ERCP), and 3D spiral CT imaging of cholangiopancreatic ducts preoperatively. Then the diagnose accordance rate of these examinational methods were compared after operations. Results: The diagnose accordance rate of 3D spiral CT imaging of cholangiopancreatic ducts was higher than those of B-mode ultrasonography, CT, or single PTC or ERCP, which showed clear images of bile duct tree and pathological changes. As to malignant obstructive jaundice, this examinational technique could clearly display the adjacent relationship between tumor and liver tissue, biliary ducts, blood vessels, and intrahepatic metastases. Conclusion: 3D spiral CT imaging of cholangiopancreatic ducts has significant value for obstructive diseases of biliary ducts, which provides effective evidence for the feasibility of tumor-resection and surgical options.展开更多
Purpose: Spleen is enlarged in a variety of clinical conditions including infectious, infiltrative, immunologic and malignant states. Evaluation of splenic size is important in every physical examination of the abdome...Purpose: Spleen is enlarged in a variety of clinical conditions including infectious, infiltrative, immunologic and malignant states. Evaluation of splenic size is important in every physical examination of the abdomen by a physician. Determination of its size by palpation can be extremely inaccurate because spleen is never palpable till it is enlarged 2 to 3 times its own size. The accurate diagnosis of splenic enlargement is a matter of considerable importance as it is a useful guide for arriving at a diagnosis of the disease. It is therefore of utmost importance to resort to a mechanism that will give us an accurate estimation of the size of spleen. Aim of this work was to determine the normal range of spleen dimensions in average adult Saudi Arabian population and compare it with the published data. Methods: CT scans of 34 adult patients (male and female) aged between 20 - 70 years, having no splenic disorders, were collected from department of radio-diagnosis King Khalid Hospital Al-Kharj, KSA. Splenic volume was measured by two methods—by volumetric software and the prolate ellipsoid formula. Results: The average splenic volume of all subjects was 161.42 ± 54.91 cm3 with a range of 106 - 319 cm3. The average splenic volume of males was 196.95 ± 48.70 cm3 and that of female was 196.95 ± 26.97 cm3. Conclusions: These results provide normative data for evaluating patients with splenic enlargement.展开更多
AIM:To evaluate the use of three-dimensional imaging of pancreatic carcinoma using multidetector computed tomography(CT)in a prospective study.METHODS:Ten patients with suspected pancreatic tumors were examined prospe...AIM:To evaluate the use of three-dimensional imaging of pancreatic carcinoma using multidetector computed tomography(CT)in a prospective study.METHODS:Ten patients with suspected pancreatic tumors were examined prospectively using multidetec-tor CT(Somatom Sensation 16,Siemens,Erlangen,Germany).The images were evaluated for the pres-ence of a pancreatic carcinoma and invasion of the peripancreatic vessels and surrounding organs.Using the isotropic CT data sets,a three-dimensional image was created with automatic vascular analysis and semi-automatic segmentation of the organs and pancreatic tumor by a radiologist.The CT examinations and the three-dimensional images were presented to the sur-geon directly before and during the patient's operation using the Medical Imaging Interaction Toolkit-based software "ReLiver".Immediately after surgery,the value of the two images was judged by the surgeon.The operation and the histological results served as the gold standard.RESULTS:Nine patients had a pancreatic carcinoma(all pT3),and one patient had a serous cystadenoma.One tumor inf iltrated the superior mesenteric vein.The inf iltration was correctly evaluated.All carcinomas were resectable.In comparison to the CT image with axial and coronal reconstructions,the three-dimensional image was judged by the surgeons as better for operation planning and consistently described as useful.CONCLUSION:A 3D-image of the pancreas repre-sents an invaluable aid to the surgeon.However,the 3D-software must be further developed in order to be integrated into daily clinical routine.展开更多
Instantaneous three-dimensional (3D) density distributions of a shock-cell structure of perfectly and imperfectly expanded supersonic microjets escaping into an ambient space are measured. For the 3D observation of su...Instantaneous three-dimensional (3D) density distributions of a shock-cell structure of perfectly and imperfectly expanded supersonic microjets escaping into an ambient space are measured. For the 3D observation of supersonic microjets, non-scanning 3D computerized tomography (CT) technique using a 20-directional quantitative schlieren optical system with flashlight source is employed for simultaneous schlieren photography. The 3D density distributions data of the microjets are obtained by 3D-CT reconstruction of the projection’s images using maximum likelihood-expectation maximization. Axisymmetric convergent-divergent (Laval) circular and square micro nozzles with operating nozzle pressure ratio 5.0, 4.5, 4.0, 3.67, and 3.5 have been studied. This study examines perfectly expanded, overexpanded, and underexpanded supersonic microjets issued from micro nozzles with fully expanded jet Mach numbers <em>M</em><em><sub>j</sub></em> ranging from 1.47 - 1.71, where the design Mach number is <em>M<sub>d</sub></em> = 1.5. A complex phenomenon for free square microjets called axis switching is clearly observed with two types “upright” and “diagonal” of “cross-shaped”. The initial axis-switching is 45<span style="white-space:nowrap;">°</span> within the first shock-cell range. In addition, from the symmetry and diagonal views of square microjets for the first shock-cells, two different patterns of shock waves are viewed. The shock-cell spacing and supersonic core length for all nozzle pressure ratios are investigated and reported.展开更多
基金Supported by a grant of Jiangxi Province Scientific Technologic Foundation (No. E990611)
文摘Objective: Computerized tomography (CT) plays an important role in the diagnosis of diseases of biliary tract. Recently, three dimensions (3D) spiral CT imaging has been used in surgical diseases gradually. This study was designed to evaluate the diagnostic value of 3D spiral CT imaging of cholangiopancreatic ducts on obstructive jaundice. Methods: Thirty patients with obstructive jaundice had received B-mode ultrasonography, CT, percutaneous transhepatic cholangiography (PTC) or endoscopic retrograde cholangiopancreatography (ERCP), and 3D spiral CT imaging of cholangiopancreatic ducts preoperatively. Then the diagnose accordance rate of these examinational methods were compared after operations. Results: The diagnose accordance rate of 3D spiral CT imaging of cholangiopancreatic ducts was higher than those of B-mode ultrasonography, CT, or single PTC or ERCP, which showed clear images of bile duct tree and pathological changes. As to malignant obstructive jaundice, this examinational technique could clearly display the adjacent relationship between tumor and liver tissue, biliary ducts, blood vessels, and intrahepatic metastases. Conclusion: 3D spiral CT imaging of cholangiopancreatic ducts has significant value for obstructive diseases of biliary ducts, which provides effective evidence for the feasibility of tumor-resection and surgical options.
文摘Purpose: Spleen is enlarged in a variety of clinical conditions including infectious, infiltrative, immunologic and malignant states. Evaluation of splenic size is important in every physical examination of the abdomen by a physician. Determination of its size by palpation can be extremely inaccurate because spleen is never palpable till it is enlarged 2 to 3 times its own size. The accurate diagnosis of splenic enlargement is a matter of considerable importance as it is a useful guide for arriving at a diagnosis of the disease. It is therefore of utmost importance to resort to a mechanism that will give us an accurate estimation of the size of spleen. Aim of this work was to determine the normal range of spleen dimensions in average adult Saudi Arabian population and compare it with the published data. Methods: CT scans of 34 adult patients (male and female) aged between 20 - 70 years, having no splenic disorders, were collected from department of radio-diagnosis King Khalid Hospital Al-Kharj, KSA. Splenic volume was measured by two methods—by volumetric software and the prolate ellipsoid formula. Results: The average splenic volume of all subjects was 161.42 ± 54.91 cm3 with a range of 106 - 319 cm3. The average splenic volume of males was 196.95 ± 48.70 cm3 and that of female was 196.95 ± 26.97 cm3. Conclusions: These results provide normative data for evaluating patients with splenic enlargement.
文摘AIM:To evaluate the use of three-dimensional imaging of pancreatic carcinoma using multidetector computed tomography(CT)in a prospective study.METHODS:Ten patients with suspected pancreatic tumors were examined prospectively using multidetec-tor CT(Somatom Sensation 16,Siemens,Erlangen,Germany).The images were evaluated for the pres-ence of a pancreatic carcinoma and invasion of the peripancreatic vessels and surrounding organs.Using the isotropic CT data sets,a three-dimensional image was created with automatic vascular analysis and semi-automatic segmentation of the organs and pancreatic tumor by a radiologist.The CT examinations and the three-dimensional images were presented to the sur-geon directly before and during the patient's operation using the Medical Imaging Interaction Toolkit-based software "ReLiver".Immediately after surgery,the value of the two images was judged by the surgeon.The operation and the histological results served as the gold standard.RESULTS:Nine patients had a pancreatic carcinoma(all pT3),and one patient had a serous cystadenoma.One tumor inf iltrated the superior mesenteric vein.The inf iltration was correctly evaluated.All carcinomas were resectable.In comparison to the CT image with axial and coronal reconstructions,the three-dimensional image was judged by the surgeons as better for operation planning and consistently described as useful.CONCLUSION:A 3D-image of the pancreas repre-sents an invaluable aid to the surgeon.However,the 3D-software must be further developed in order to be integrated into daily clinical routine.
文摘Instantaneous three-dimensional (3D) density distributions of a shock-cell structure of perfectly and imperfectly expanded supersonic microjets escaping into an ambient space are measured. For the 3D observation of supersonic microjets, non-scanning 3D computerized tomography (CT) technique using a 20-directional quantitative schlieren optical system with flashlight source is employed for simultaneous schlieren photography. The 3D density distributions data of the microjets are obtained by 3D-CT reconstruction of the projection’s images using maximum likelihood-expectation maximization. Axisymmetric convergent-divergent (Laval) circular and square micro nozzles with operating nozzle pressure ratio 5.0, 4.5, 4.0, 3.67, and 3.5 have been studied. This study examines perfectly expanded, overexpanded, and underexpanded supersonic microjets issued from micro nozzles with fully expanded jet Mach numbers <em>M</em><em><sub>j</sub></em> ranging from 1.47 - 1.71, where the design Mach number is <em>M<sub>d</sub></em> = 1.5. A complex phenomenon for free square microjets called axis switching is clearly observed with two types “upright” and “diagonal” of “cross-shaped”. The initial axis-switching is 45<span style="white-space:nowrap;">°</span> within the first shock-cell range. In addition, from the symmetry and diagonal views of square microjets for the first shock-cells, two different patterns of shock waves are viewed. The shock-cell spacing and supersonic core length for all nozzle pressure ratios are investigated and reported.
