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Chinese Journal of Radiology ; (12): 229-232, 2019.
Article in Chinese | WPRIM | ID: wpr-745232


Objective To investigate the influence of liver fat deposition on the quantification of the liver iron overload using fast-kilovolt-peak switching dual-energy CT imaging and material decomposition technique. Methods A total of 20 healthy SD rats were taken to make 18 PVC tube of homogenate of fresh liver tissue. The dextran with concentration of 50, 40, 30, 20, 10 and 0 mg/ml were mixed with rat liver homogenate and triglyceride with three different concentrations (add fat with volume percentage of 60%, 30%, 10% and to simulate severe, moderate and mild fatty liver respectively). All samples were placed in standard phantom according to the order of iron concentration from high to low and scanned by GE Revolution CT 256 slices scanner in GSI mode with rapid tube voltage switching between 80 and 140 kVp and with tube current 200 mA, 320 mA, 485 mA respectively. The images of iron (fat)-based substance pair were reconstructed and the virtual iron concentration (VIC) value were recorded. The correlation between VIC and the actual liver concentration (LIC) of the three sets of tube currents (200, 320, 485 mA) was analyzed by Spearman correlation analysis and linear regression. Results LIC and VIC were highly positively correlated with the liver iron deposition model under different tube currents (r value was 0.900 to 1.000, P<0.05). The presence of fat will result in the decrease of VIC value. In a certain X-ray energy range and certain liver iron concentration, the higher the fat content, the more liver iron concentration underestimation were happened in VIC. At 200, 320 and 485 mA, the crossing points of linear equations for 30%and 10%fatty liver iron deposition models were located at VIC=12.682, 12.470 and 13.447 mg/cm3, respectively. Conclusions The fast-kilovolt-peak switching dual-energy CT imaging and material decomposition techniques can be used for quantitative evaluation of liver iron with hepatic steatosis. The presence of fat will lead to a decrease in VIC measurement.

Journal of Practical Radiology ; (12): 1244-1247, 2017.
Article in Chinese | WPRIM | ID: wpr-608934


Objective To assess whether aortic valve calcification (AVC) and mitral annual calcification (MAC) is independent predictors for coronary artery disease (CAD).Methods Coronary CT angiography(CCTA) data in a total of 263 patients were included in this study,including 30 patients with MAC, 82 patients with AVC and 31 patients with MAC+AVC;meanwhile other 120 patients without valvular calcification were regarded as a control group.Five indicators were used to evaluate the extent and severity of CAD, namely, the prevalence of coronary plaque, multi-coronary vessels lesions, degrees of coronary artery narrowing, incidence of moderate to severe coronary artery calcification score and mean number of affected coronary artery segments.The correlations of MAC,AVC,MAC+AVC with CAD were analyzed by Logistic regression analysis.Results The presence and severity of CAD were significantly greater in patients with MAC, AVC and MAC+AVC than those in control group.After adjustment for CAD conventional risk factors,Logistic regression analysis revealed that AVC,MAC and MAC+AVC were independently associated with the presence and severity of CAD.Conclusion AVC and MAC are independent predictors for CAD and often predict the more presence and greater severity of CAD.

Chinese Journal of Medical Imaging ; (12): 934-937,942, 2015.
Article in Chinese | WPRIM | ID: wpr-603638


PurposePrimary chest wall rhabdomyosarcoma (RMS) is very rare with limited imaging characteristic studies in the literature. This paper analyzes the CT imaging features of chest wall RMS in children to improve the diagnostic accuracy.Materials and MethodsThe imaging data of contrast enhanced CT scan of pathology conifrmed chest wall RMS in ifve children were analyzed.ResultsThe lesion was located in the anterior chest wall in one case, in the posterior chest wall in two cases, and the lateral chest wall in two cases (axillary). The tumors were round or spindle in shape with shallow spiculation. Plain CT showed heterogeneous density with patchy low-density necrotic area in two cases, and homogeneous attenuation in three patients. In all ifve cases there was no calciifcation or fatty tissue. The tumor involvement of adjacent spinal canal was seen in one case. Visceral compression was evident including lung parenchyma in one case, heart and liver in one case. Tumor blood vessel growth was seen in two cases. All ifve lesions were adjacent to the ribs, humerus, scapula and the spine with bone destruction in one case. On contrast enhanced scan, all ifve cases demonstrated heterogeneous mild to moderate enhancement, more prominent in the periphery. There were enlarged feeding arteries. Necrotic areas did not enhance. In two cases there were pulmonary metastases. Pleural effusion and ascites were identiifed in one case. There was lymph node metastasis in one case.ConclusionThe CT manifestation of children's chest wall RMS for chest wall include large soft tissue mass, heterogeneous density, no calciifcation or fatty tissue, partial necrosis, adjacent tissue compression, lymph node or distant metastasis. Combining with clinical manifestations, comprehensive analysis of contrast enhanced CT imaging can improve diagnostic accuracy.

Journal of Practical Radiology ; (12): 778-782, 2014.
Article in Chinese | WPRIM | ID: wpr-448454


Objective To investigate the feasibility and clinical application of prospective ECG-gated scan and adaptive cardio se-quence scan of dual-source CT coronary angiography.Methods 255 patients who underwent coronary CT angiography using a dual-source CT scanner were divided into two groups:group A underwent prospective scan,group B underwent retrospective scan.The two groups were further subdivided into low heart rate group and high heart rate group,recorded as A1(n=51),A2(n=89),B1(n=26), B2(n=89),respectively.Group A1 preceded with prospective ECG gated scan;group A2 performed with adaptive cardio sequence scan;group B1 and B2 underwent retrospective scan.All of them applied ATCM (automatic tube current modulation)technique. Effective dose was recorded.The image quality was assessed by two experienced radiologists with a four-point grading scale.Results The excellent or good image quality (score 1 and 2)of the four groups were above 95%,and no statistical differences in images scores was detected in A1 and B1 (P =0.726),A2 and B2 (P =0.079).Effective dose was significantly different in A1 and B1(P <0.001),A2 and B2 (P <0.001),and the former decreased 50% and 40% as compared with the latter.Conclusion Using prospective ECG gated scan and adaptive cardio sequence scan,assessable image quality of coronary artery can be acquired with dual source CT (heart rate<90 beast per minute),and radiation dose can be obviously reduced.

Article in Chinese | WPRIM | ID: wpr-542718


Objective To study the value of CT and barium radiograpy in diagnosis of gastric schwannoma.Methods A retrospectiveanalysis was made on imaging of 8 patients with pathologically approved gastric schwannoma.Plain abdominal CT scan was performed in all patients, additional enhanced CT scan was carried out in 6 cases and barium radiography of upper digestive tract was carried out in 5 cases. Results The lesions localized in fundus ventriculi in 2 cases, curvatura ventriculi minor in 4 cases and pars pylorica in 2 cases. Three main types were seen: localized mass type (n=4), localized thickening of gastric paries type (n=2) and huge mass type (n=2).Conclusion In comparison with barium radiography of upper digestive tract, CT can accurately demonstrate the shape, the location and internal structure of lesions.Three main patterns of this lesion also can be showed clearly by CT scans and suggestive diagnosis can be made in some patients combined with barium radiography of upper digestive tract images.