Induced polarization （IP） 3D tomography with the similar central gradient array combines IP sounding and IP profiling to retrieve 3D resistivity and polarization data rapidly. The method is characterized by high spa...Induced polarization （IP） 3D tomography with the similar central gradient array combines IP sounding and IP profiling to retrieve 3D resistivity and polarization data rapidly. The method is characterized by high spatial resolution and large probing depth. We discuss data acquisition and 3D IP imaging procedures using the central gradient array with variable electrode distances. A 3D geoelectric model was constructed and then numerically modeled. The data modeling results suggest that this method can capture the features of real geoelectric models. The method was applied to a polymetallic mine in Gansu Province. The results suggest that IP 3D tomography captures the distribution of resistivity and polarization of subsurface media, delineating the extension of abrupt interfaces, and identifies mineralization.展开更多
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
OBJECTIVE: To evaluate the diagnostic accuracy of three-dimensional CT angiography in the surgical treatment of intracranial aneurysms. METHODS: Twenty-four patients suspected of intracranial aneurysms underwent routi...OBJECTIVE: To evaluate the diagnostic accuracy of three-dimensional CT angiography in the surgical treatment of intracranial aneurysms. METHODS: Twenty-four patients suspected of intracranial aneurysms underwent routine catheter four-vessel angiography, three dimensional CT angiography (3D-CTA), magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA). RESULTS: A total of 28 aneurysms were detected by CT angiography in this study. Twenty-one patients each had a single aneurysm, two patients each had two aneurysms, and one had three aneurysms. The shapes of aneurysms revealed by 3D-CTA were round in 20 lesions, elliptical in 5, and 1 obulated in 3. Of the 24 lesions which were completely disclosed during surgery, the shapes correlated well with the 3D-CT angiograms. The mean diameter of the aneurysmal neck was 5.9 mm in 3D-CTA images, with the smallest being 1.6 mm and the largest 13.7 mm. The size was very close to the actual size measured at surgery (P展开更多
基金funded jointly by the National High Technology Research and Development Program(863 Program:No.2014AA06A610)special funds for basic scientific research business expenses of the Chinese Academy of Geological Sciences(No.YYWF201632)the National Major Scientific Instruments and Equipment Development Projects(No.2011YQ050060)
文摘Induced polarization （IP） 3D tomography with the similar central gradient array combines IP sounding and IP profiling to retrieve 3D resistivity and polarization data rapidly. The method is characterized by high spatial resolution and large probing depth. We discuss data acquisition and 3D IP imaging procedures using the central gradient array with variable electrode distances. A 3D geoelectric model was constructed and then numerically modeled. The data modeling results suggest that this method can capture the features of real geoelectric models. The method was applied to a polymetallic mine in Gansu Province. The results suggest that IP 3D tomography captures the distribution of resistivity and polarization of subsurface media, delineating the extension of abrupt interfaces, and identifies mineralization.
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OBJECTIVE: To evaluate the diagnostic accuracy of three-dimensional CT angiography in the surgical treatment of intracranial aneurysms. METHODS: Twenty-four patients suspected of intracranial aneurysms underwent routine catheter four-vessel angiography, three dimensional CT angiography (3D-CTA), magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA). RESULTS: A total of 28 aneurysms were detected by CT angiography in this study. Twenty-one patients each had a single aneurysm, two patients each had two aneurysms, and one had three aneurysms. The shapes of aneurysms revealed by 3D-CTA were round in 20 lesions, elliptical in 5, and 1 obulated in 3. Of the 24 lesions which were completely disclosed during surgery, the shapes correlated well with the 3D-CT angiograms. The mean diameter of the aneurysmal neck was 5.9 mm in 3D-CTA images, with the smallest being 1.6 mm and the largest 13.7 mm. The size was very close to the actual size measured at surgery (P
