Single coronary artery originating from the right sinus Valsalva and ability to work

We present a case of a 56-year-old male electrician who was admitted to the hospital with atrial fibrillation, atypical chest pain and dyspnea. He gave a history that on the morning he had working for almost 4 hours carrying out various activities with considerable physical effort. After cardioversion, conventional coronary angiography revealed a suspect of single coronary vessel (SCA) arising from the right sinus of Valsalva. The patient underwent multislice computed tomography that showed a SCA arising from the right sinus Valsalva and dividing in Right Coronary Artery (RCA) and Left Main coronary artery (LM). The finding of posterior course of the LM without atherosclerotic has proved crucial for the expression of an opinion of working capacity even with limitation.

Aplicação do algoritmo FDK para a reconstrução de imagens tomográficas multicortes / Application of the FDK algorithm for multi-slice tomographic image reconstruction

O presente trabalho consiste no estudo e aplicação do algoritmo FDK (Feldkamp-Davis-Kress) para a reconstrução de imagens tomográficas utilizando a geometria de feixe cônico, resultando na implementação de um sistema adaptado de tomografia computadorizada multicortes (TCMC). O algoritmo FDK é a base de algoritmos de retroprojeção filtrada utilizados nos equipamentos de TCMC comercializados atualmente. Para a aquisição das projeções, utilizou-se uma plataforma giratória com goniômetro acoplado, um equipamento de raios X e um detector digital tipo CCD (charge-coupled device). Para processar a reconstrução das imagens foi utilizado um computador com processador Pentium® XEONTM 3.0, no qual foi implementado o algoritmo FDK. Inicialmente foi aplicado o algoritmo FDK original, no qual se assume o caso físico ideal no processo de medições. Em seguida foram incorporadas ao algoritmo algumas correções de artefatos relacionados ao processo de medição das projeções, tais como a alteração do filtro utilizado na etapa que precede a retroprojeção, para aumentar a razão sinal ruído das imagens e uma correção digital da centralização do sistema de aquisição das projeções. Para a calibração do sistema utilizou-se um objeto com distribuição de coeficientes de atenuação linear (μ(r)) conhecida, que foi fabricado com esta finalidade. Por fim, o sistema de TCMC implementado foi utilizado na reconstrução tomográfica multicortes de um objeto não homogêneo, cuja distribuição μ(r) é desconhecida. Para avaliar a robustez do sistema e sua reprodutibilidade, foram analisados alguns aspectos das imagens reconstruídas, tais como: relação sinal ruído, concordância entre os valores de número CT medidos e determinados teoricamente, e a fidelidade na representação do objeto imageado. Durante a calibração do sistema foi verificada a relação linear entre o número CT e o coeficiente de atenuação linear dos materiais, o que valida a aplicação do sistema implementado para a caracterização...

This work consisted on the study and application of the FDK (Feldkamp- Davis-Kress) algorithm for tomographic image reconstruction using cone-beam geometry, resulting on the implementation of an adapted multi-slice computed tomography (MSCT) system. For the acquisition of the projections, a rotating platform coupled to a goniometer, an X-ray equipment and a digital image detector CCD (charge-coupled device) type were used. The FDK algorithm was implemented on a computer with a Pentium® XEONTM 3.0 processor, which was used for the reconstruction process. Initially, the original FDK algorithm was applied considering only the ideal physical conditions in the measurement process. Then some artifacts corrections related to the projections measurement process were incorporated. The implemented MSCT system was calibrated. A specially designed and manufactured object with a known linear attenuation coefficient distribution (μ(r)) was used for this purpose. Finally, the implemented MSCT system was used for multi-slice tomographic reconstruction of an inhomogeneous object, whose distribution μ(r) was unknown. Some aspects of the reconstructed images were analyzed to assess the robustness and reproducibility of the system. During the system calibration, a linear relationship between CT number and linear attenuation coefficients of materials was verified, which validate the application of the implemented multi-slice tomographic system for the characterization of linear attenuation coefficients of distinct several objects.

The application of multi-slice spiral CT portography in pancreatic portal hypertension disease / 中华消化杂志

Objective To study the application of multi-slice spiral CT(MSCT) portography in diagnonsis of pancreatic portal hypertension. Methods Forty-seven patients with lesion in body or tail of pancrease,47 normal subjects and 126 patients with portal hypertension underwent MSCT portography with LightSpeed 16 CT scanner. The inner diameter of portal system and the main collateral veins were measured in maximun intensity projection (MIP) image. The volume of liver and spleen were also measured in volume rendering (VR) image. The liver parenchyma and main portal vein enhancement in portal vein phase were also taken. The endoscopy examination was made in 57 patiens with portal hypertension. Results In 47 patiens with lesion in body or tail of pancreas , stenosis or occlusion of spleen vein were found in 38 patients(pancreatic portal hypertension in 27 patients, chronic and acute pancreatitis in 11 patients). In 38 patients with pancreatic portal hypertension, esophageal varices was found in 5 patients(13.2%), gastric fundus varix in 25 patients (65.8%), gastric body variees in 22 patients (57.9%), short-gastric vein/post-gastric vein(SGV/PGV) in 26 patients (68.4%), coronal gastric vein in 26 patients (68.4%),dilated gasto-omenta vein in 24 patients(63.2%), mesenterica varicesin 1 patient, splenic vein occlusion in 14 patients (36.8%), splenic vein stenosis in 23 patinets(63.2%). Conclusions The patients with pancreatic portal hypertension were demonstrate characteristic changes in MSCT portography. The MSCT portography is helpful in etiological diagnosis of pancreatic portal hypertension by supplying images in vessel morphology.