AIM:To identify the characteristics of morphology, loca- tion and collateral circulation involved in paraesophageal varices (para-EV) of portal hypertension patients with 64-row multidetector computed tomograghy (MDCT...AIM:To identify the characteristics of morphology, loca- tion and collateral circulation involved in paraesophageal varices (para-EV) of portal hypertension patients with 64-row multidetector computed tomograghy (MDCT). METHODS: Fifty-two of 501 patients with portal hypertensive cirrhosis accompanied with esophageal varices were selected for 64-row MDCT examination af- ter the observation of para-EV. The CT protocol includ- ed unenhanced, arterial and portal phases with a slice thickness of 0.625 mm and a scanning field of 2 cm above the bifurcation to the lower edge of kidney. The CT portal venography (CTPV) was reformatted on AW4.3 workstation. The characteristics of origina- tion, location, morphology and collateral circulation in para-EV were observed. RESULTS: Among the 52 cases of para-EV, 50 showed the originations from the posterior branch of left gastric vein, while the others from the anterior branch. Fifty cases demonstrated their locations close to the esoph- ageal-gastric junction, and the other two cases were extended to the inferior bifurcation of the trachea. The circuitous pattern was observed in 16 cases, while reticulated pattern was seen in 36 cases. Collateral circulation identifi ed 4 cases of single periesophageal varices (peri-EV) communication, 3 cases of single hemiazygous vein, one case of single inferior vena cava, 41 cases of mixed type (collateral communica-tions of at least 2 of above mentioned types) and 3 cases of undetermined communications. Among all the cases, 43 patients showed the communications between para-EV and peri-EV, while hemiazygous vein (43 cases) and inferior vena cava (5 cases) were also involved. CONCLUSION: Sixty-four-row multidetector computed tomograghy portal venography could display the loca- tion, morphology, origin, and collateral types of para- EV, which provides important and referable information for clinical management and disease prognosis.展开更多
D velocity images of the crust and upper mantle in the Tianshan are established by means of seismic tomograghy. From the results, some understanding can be achieved as follows: (1) The northern and central parts of th...D velocity images of the crust and upper mantle in the Tianshan are established by means of seismic tomograghy. From the results, some understanding can be achieved as follows: (1) The northern and central parts of the Tianshan are the uplifted areas with high velocities. The low velocity areas in front of the northern and southern flanks of the Tianshan are formed by the southern margin of the Junggar Basin, Turpan Basin, Kuqa depression, Kalpin fault block and Kaxgar depression. The Ili Basin and the western Kunlun appear as intracrustal stable high velocity blocks, while the Bachu uplift extends down to the crustal bottom. Along the main peaks of the Tianshan and Mt. Kongur of the western Kunlun, the Moho depresses on a great scale to form five large low velocity areas. (2) In the northern Tianshan snd western Junggar Basin, the lithosphere is thicker and features a high velocity probably with an asthenolith layer existing on the top of the upper mantle. In the southern Tianshan, the feature of the lithosphere is not very clear, and the existence of a comic low velocity block between 120-280 km depth in the Kaxgar area is presumably related with the upwelling of astenolith from the upper mantle. (3) Some relation does exist between velocity structures and seismic activities, especially those gradient belts between the low velocity zone in the upper crust and the low velocity zone in the lower crust may be the tectonic positions for the preparation of moderate-strong earthquakes. (4) Seismically active areas on the northern and southern flanks of the Tianshan are locations with most inhomogeneous crustal media and welldeveloped deep faults. Fractures or interlayer-gliding are very likely to occur under the action of tectonic forces and thus to induce earthquakes in these areas.展开更多
基金The Science Technology Program of Beijing Education Committee, No.KM200810025002
文摘AIM:To identify the characteristics of morphology, loca- tion and collateral circulation involved in paraesophageal varices (para-EV) of portal hypertension patients with 64-row multidetector computed tomograghy (MDCT). METHODS: Fifty-two of 501 patients with portal hypertensive cirrhosis accompanied with esophageal varices were selected for 64-row MDCT examination af- ter the observation of para-EV. The CT protocol includ- ed unenhanced, arterial and portal phases with a slice thickness of 0.625 mm and a scanning field of 2 cm above the bifurcation to the lower edge of kidney. The CT portal venography (CTPV) was reformatted on AW4.3 workstation. The characteristics of origina- tion, location, morphology and collateral circulation in para-EV were observed. RESULTS: Among the 52 cases of para-EV, 50 showed the originations from the posterior branch of left gastric vein, while the others from the anterior branch. Fifty cases demonstrated their locations close to the esoph- ageal-gastric junction, and the other two cases were extended to the inferior bifurcation of the trachea. The circuitous pattern was observed in 16 cases, while reticulated pattern was seen in 36 cases. Collateral circulation identifi ed 4 cases of single periesophageal varices (peri-EV) communication, 3 cases of single hemiazygous vein, one case of single inferior vena cava, 41 cases of mixed type (collateral communica-tions of at least 2 of above mentioned types) and 3 cases of undetermined communications. Among all the cases, 43 patients showed the communications between para-EV and peri-EV, while hemiazygous vein (43 cases) and inferior vena cava (5 cases) were also involved. CONCLUSION: Sixty-four-row multidetector computed tomograghy portal venography could display the loca- tion, morphology, origin, and collateral types of para- EV, which provides important and referable information for clinical management and disease prognosis.
文摘D velocity images of the crust and upper mantle in the Tianshan are established by means of seismic tomograghy. From the results, some understanding can be achieved as follows: (1) The northern and central parts of the Tianshan are the uplifted areas with high velocities. The low velocity areas in front of the northern and southern flanks of the Tianshan are formed by the southern margin of the Junggar Basin, Turpan Basin, Kuqa depression, Kalpin fault block and Kaxgar depression. The Ili Basin and the western Kunlun appear as intracrustal stable high velocity blocks, while the Bachu uplift extends down to the crustal bottom. Along the main peaks of the Tianshan and Mt. Kongur of the western Kunlun, the Moho depresses on a great scale to form five large low velocity areas. (2) In the northern Tianshan snd western Junggar Basin, the lithosphere is thicker and features a high velocity probably with an asthenolith layer existing on the top of the upper mantle. In the southern Tianshan, the feature of the lithosphere is not very clear, and the existence of a comic low velocity block between 120-280 km depth in the Kaxgar area is presumably related with the upwelling of astenolith from the upper mantle. (3) Some relation does exist between velocity structures and seismic activities, especially those gradient belts between the low velocity zone in the upper crust and the low velocity zone in the lower crust may be the tectonic positions for the preparation of moderate-strong earthquakes. (4) Seismically active areas on the northern and southern flanks of the Tianshan are locations with most inhomogeneous crustal media and welldeveloped deep faults. Fractures or interlayer-gliding are very likely to occur under the action of tectonic forces and thus to induce earthquakes in these areas.
