Diagnostic Value of 16 Slices Spiral-CT for Portal Vein Disorders

Summary: The diagnostic value of 16-slices spiral computed tomography (CT) for portal vein disorders was evaluated. Forty-one patients were scanned by the 16-slices spiral-CT. The celiac trunk, portal vein and their branches were reconstructed by volume rendering (VR), multiplanar volume reconstruction (MPVR) and maximum intensity projection (MIP) technique, and the results were compared with digital subtraction angiography (DSA). VR, MPVR and MIP could display celiac trunk, portal vein, inferior vena cava and their branches and extent of portal vein-vena cava shunt, portal vein emboli and the fistula of hepatic artery-portal vein. The results from 16-slices CT were better than DSA and identical with pathologic ones. The vessel three-dimension reconstruction technique of 16-slices spiral CT is valuable for evaluating the portal systemic disorders.

Ground Penetrating Radar Survey for the Location and Assessment of the Hydrocarbon Plumes at Gas Station Installations

The present paper describes the implementation of GPR 3D survey for detecting and delineating possible remains of hydrocarbon plumes on a gas station. The 3D-imaging was used for the detection of anomalous zones that were analyzed with some relevant signal attributes extracted by digital signal processing. These signal attributes or parameters have been the frequency of the maximum energy concentration on time-frequency distribution and instantaneous amplitude that could be related to the local response of the electromagnetic interaction and the presence of hydrocarbon plumes or soil contaminated areas. The implementation methodology took place at a gas station monitored with a piezometric sensor installation with soil layer information. The 3D-imaging of processed data and its slicing tool permits visualizing expected targets as pipes, tanks and installations in the subsoil exposing the anomalous zones for refined analyses. This further processing has used some spectral attributes of the signal to assess the real presence of the total petroleum hydrocarbons (TPH) providing a new effort to simplify and overcome the current state of the geophysical methods able to assess the presence of hydrocarbon plumes in industrial environments regarding the time cost of the survey and the traceable indication of the spectral shiftment shown in the plume volume.