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find Keyword "体层摄影" 516 results
  • Research Progress in Multidetector-row Computed Tomographic Presentations and Their Anatomic-pathologic Features of Aortic Dissection after Endovascular Graft Exclusion or Combined Surgical and Endovascular Treatment

    With the development of radiologic intervention, the treatments of aortic dissection are getting more and more diversified. In recent years, Debakey Ⅲ and DebakeyⅠaortic dissection has been usually treated with endovascular graft exclusion, or combined surgical and endovascular treatment. It is therefore more important to evaluate the aorta and its complications after interventional treatments. Because multidetector-row computed tomography (MDCT) has advantages, such as short examination time, high spatial resolution, and simple operation, this modality has become a first choice of non-invasive methods for the follow-up of aortic diseases after the intervention. Now the MDCT presentations and their anatomic-pathologic features of aortic dissection after endovascular graft exclusion or combined surgical and endovascular treatment are reviewed in this article.

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  • CT Features and Anatomic-Pathologic Bases of Secondary Pyogenic Peritonitis

    【Abstract】ObjectiveTo evaluate the main CT features, the morbidity of CT signs and the anatomic-pathologic bases of secondary pyogenic peritonitis (SPP). MethodsTwentyfour patients of the SPP were retrospectively studied. Emphasis was placed on the spiral CT manifestations of the SPP correlating with their anatomic-pathologic bases and the occurrence as well as the signs of primary lesions which resulted in the SPP. ResultsThe main CT manifestations of SPP revealed as follows: the thickened peritoneum, 16 in 24 cases (66.7%), of which 14 cases were smooth and 2 cases were irregular; the ascites, 15 in 24 cases (62.5%); the free air within peritoneal cavity, 9 in 24 cases (37.5%); the edema and thickening involved in the greater omentum, 8 in 24 cases (33.3%); the small bowel mesentery, 5 in 24 cases (20.8%); and the bowels’ wall, 5 in 24 cases (20.8%); the adhesions of bowels, 6 in 24 cases (25.0%). The CT manifestation of the promary lesions, which caused SPP, and the complications were shown as follows: the signs of primary lesion, 13 cases (54.2%); the inflammatory changes in retroperitoneal cavity 13 cases (54.2%); the involvements of chest 13 cases (54.2%); and the abscess in peritoneal and pelvic cavity 6 cases (25.0%). ConclusionThe main significant CT signs of SPP could be concluded as follows: thickened peritoneum, ascites, free air within peritoneal cavity, edematous and thickened greater omentum, the small bowel mesentery, and the bowels’ wall, as well as the adhesions of bowels. So, the CT scan can present plenty of CT signs, which are significant and very helpful for making an appropriate diagnosis of SPP.

    Release date:2016-08-28 04:20 Export PDF Favorites Scan
  • Invasion of Major Intrahepatic Ductal Structures by Hepatocellular Carcinoma: Multi-Detector-Row Spiral CT Manifestations

    【Abstract】Objective To investigate the imaging features of malignant invasion of major intrahepatic ductal structures (the portal and hepatic venous vasculature, the bilie duct) by primary hepatocellular carcinoma (HCC) using multidetector-row spiral CT (MDCT). Methods We retrospectively analyzed 68 documented HCC patients with tumorous invasion of the major intrahepatic ductal structures who had undergone contrast-enhanced dual-phase MDCT scanning of the upper abdomen.The morphological changes of the portal and hepatic venous vasculature, the bile duct, and the liver parenchyma at both the hepatic arterial phase and portal venous phase images were carefully observed and recorded. Results Among the 68 patients, 47 patients had malignant invasion of the intrahepatic portal venous vessels with secondary tumor thrombus formation; 12 patients had tumor involvement of the hepatic veins and intraheptic segment of the inferior vena cava; Tumor invasion of the bile duct was seen in 9 patents. The direct CT signs of tumor invasion of intrahepatic venous vessels included: ①dilatation or enlargement of the involved vein with intraluminal softtissue “filling defect”; ②enhancement of the tumor thrombus at hepatic arterial phase, the so-called “venous arterialization” phenomenon. The indirect CT signs included: ①arterial-venous shunt, ②early and heterogeneous enhancement of the hepatic parenchyma adjacent to HCC focus, ③cavernous transformation of the portal vein. The CT signs suggesting tumor invasion of the bile duct included: ①dilation of the bile ducts near or proximal to HCC lesion, ②soft-tissue nodule or mass inside the bile ducts. Conclusion Invasion of major intrahepatic ductal structures by HCC will present corresponding CT imaging features. Contrast-enhanced MDCT dualphase scanning combined with appropriate image postprocessing techniques can better evaluate the malignant invasion of major intrahepatic ductal structures.

    Release date:2016-08-28 04:44 Export PDF Favorites Scan
  • Make full use of the new imaging technology to further explore the key problems of retinal branch vein occlusion

    With high morbidity, branch retinal vein occlusion (BRVO) is a common retinal vascular disease in the clinic. Although the classic characteristics of BRVO have been recognized for a long time, the traditional understanding of BRVO has been challenged along with development and application of new imaging technologies, including the reasonable classification and staging of the disease, and the vascular characteristics at the occlusive site via multimodal imaging, etc. Thus, re-summarizing and refining these features as well as further improving and optimizing traditional imaging evaluation, can not only deepen the correct acknowledge of the entity, but also find biomarkers of prognosis of visual function, which is helpful to establish better diagnosis and treatment strategy. In the meanwhile, it is necessary that clinical characteristics of BRVO on imaging and the reliability of these imaging techniques are worth correct understanding and objective assessment.

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  • Current research status of optical coherence tomography angiography in hereditary retinochoroidal degeneration

    OCT angiography (OCTA) is a fast, noninvasive and quantifiable new technique, which is especially suitable for long-term follow-up in patients with hereditary retinochoroidal degeneration, such as retinitis pigmentosa, Best vitelliform macular dystrophy, adult onset foveomacular vitelliform dystrophy, doyne honeycomb retinal dystrophy, choroideremia and Stargardt disease. During the follow-up, clinicians can find the subtle signs that explain disease development from the blood flow imaging, quantitatively describe the vascular density, timely detect and treat choroidal neovascularization. It is significant to explore the etiology and monitor the course of these diseases. With the development of more treatments for these diseases, OCTA parameters can also be used as indicators to evaluate and compare different therapeutic effects. In the future, more quantitative indicators of OCTA will be applied to evaluate the course of hereditary retinochoroidal degeneration, and provide valuable basis for early diagnosis and treatment.

    Release date:2019-01-19 09:03 Export PDF Favorites Scan
  • The status in the application of optical coherence tomography angiography in noninfectious uveitis

    Noninfectious uveitis refers to a category of inflammatory diseases involving the uvea, vitreous, optic disk and retina, with the exception of infectious factors or masquerade syndrome. These kind of blinding diseases are frequently recurrent, and the diagnosis and follow-up require fundus imaging techniques. OCT angiography (OCTA) is a rapid, noninvasive and quantifiable blood flow imaging modality that provides a depiction of the microvasculature morphology of the retinal and choroidal through different segmentation and detects the abnormal blood perfusion as well as the neovascularization. OCTA plays an important role in the diagnosis, assessment and follow-up for anterior uveitis, posterior uveitis and pan-uveitis such as Vogt-Koyanagi-Harada disease, Behçet’s disease, ocular sarcoidosis, birdshot chorioretinopathy, serpiginous choroiditis, multifocal choroiditis, punctate inner choroidopathy, acute zonal occult outer retinopathy, acute posterior multifocal placoid pigment epitheliopathy, multiple evanescent white dot syndrome, and also provides clue about their pathophysiologic mechanisms.

    Release date:2019-07-16 05:35 Export PDF Favorites Scan
  • 16例基底膜层状玻璃膜疣患者影像特征

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  • 增生型糖尿病视网膜病变黄斑裂孔自发闭合一例

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  • Changes in the vessel densities of macular and optic nerve head and their relationships with axial length in pathological myopia

    ObjectiveTo observe the changes of vessel densities (VD) in the macula and optic disc and its correlation with axial length (AL) in pathological myopia (PM). MethodsA retrospective clinical study. A total of 171 eyes from 171 patients admitted to Department of Ophthalmology of Jinshan Hospital of Fudan University from June 2019 to December 2019 were included in this study. Among them, there were 72 males and 99 females; age was 35.0±10.8 years old. The patients were divided into PM group, high myopia (HM) group and non-HM group, 51 cases with 51 eyes, 70 cases with 70 eyes, and 50 cases with 50 eyes, respectively. Optical coherence tomography angiography was used to scan the macular and optic disc areas of all the examined eyes in the range of 6 mm×6 mm. According to the early treatment of diabetic retinopathy study, the 6 mm macular and optic disc scan range was centered on the macular fovea and optic disc, respectively, then divided into two concentric circles with diameters of 1 mm of central area, an annulus between 1-3 mm circles of paracentral area. The paracentral area was divided into superior, inferior, nasal, temporal four quadrants by 2 radiation lines. The VD of superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina, and choriocapillaris layer were calculated in the central, superior, inferior, nasal, and temporal areas, respectively. The VD of PM, HM and non-HM groups were compared. The variance analysis was used to compare the VD among the three groups; Pearson’s correlation was used to assess the correlation between VD and AL. ResultsThe perifoveal VD of the SCP, outer retina and choriocapillaris layers were all lower in the PM than those of HM and non-HM group, and the differences were statistically significant (P<0.05). The VD of DCP macular central was higher in the PM than in the HM group, and the difference was statistically significant (P=0.020). In the optic disc, the VD were lower in the PM group than in the non-HM group except for the area of DCP superior, inferior, temporal, outer retinal center, and the differences were statistically significant (P<0.05). The results of correlation analysis showed that the VD in the DCP macular central, ONH superior and the choriocapillaris ONH central were not correlated with AL (P=0.647, 0.688, 0.146), and the other VDs were negatively correlated with AL (P<0.05). ConclusionCompared with HM and non-HM groups, the majority of VDs in macular and ONH are lower in participants with PM.

    Release date:2022-07-18 03:05 Export PDF Favorites Scan
  • Research progress of optical coherence tomography biomarkers in macular edema secondary to retinal vein occlusion

    Retinal vein occlusion (RVO) is one of the most common retinal vascular diseases causing blindness, macular edema (ME) is often secondary to it, which causes serious visual impairment to patients. Imaging biomarkers in the changes of retina and choroid of ME secondary to RVO (RVO-ME) have important clinical value in the evaluation of condition, curative effect and visual acuity prediction of patients with RVO-ME. Among them, the disorganization of the retinal inner layers, the integrity of external limiting membrane and ellipsoid zone, and the change of central macular thickness are reliable indexes to evaluate the prognosis of visual acuity; hyperreflective foci, subretinal fluid and intraretinal fluid can be used as important parameters to reflect the level of inflammation; prominent middle limiting membrane and paracentral acute middle maculopathy are the objective basis for judging the degree of retinal ischemia; the changes of choroidal vascular index and choroidal thickness also have potential advantages in evaluating the progress of the disease. Accurately grasp the characteristics of biological markers of RVO-ME related optical coherence tomography is conducive to its reasonable and accurate use in the clinical diagnosis and treatment of RVO-ME, and helpful to further explore the pathogenesis of the disease.

    Release date:2024-06-18 11:04 Export PDF Favorites Scan
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