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find Keyword "Tomography" 366 results
  • Multimodality imaging features of different properties in multifocal choroiditis

    Objective To observe multimodality imaging features of different properties in multifocal choroiditis (MFC). Methods Twenty-eight patients (51 eyes) with MFC were enrolled in this study. There were 10 males and 18 females. The patients aged from 31 to 49 years, with the mean age of (41.5±0.8) years. There were 23 bilateral patients and 5 unilateral patients. All patients underwent best corrected visual acuity (BCVA), slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus colorized photography, infrared fundus photography, fundus autofluorescence (FAF), fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) examinations. The lesions were classified as active inflammatory lesion, inactive inflammatory lesion, active choroidal neovascularization (CNV) and inactive CNV. The multimodality imaging features of different properties in MFC was observed. Results In fundus colour photography, the boundaries of active inflammatory lesions were blurry, while inactive inflammatory lesions had relatively clear boundaries. Secondary active CNV showed mild uplift and surrounding retinal edema; Secondary active CNV lesions showed mild uplift, retinal edema around the lesion; Secondary non-active CNV had no retinal exudate edema lesions, but had lesions fibrosis and varying degrees of pigmentation. Infrared fundus examination revealed that both active and inactive inflammatory lesions showed a uniform punctate or sheet-like fluorescence. The fluorescence of CNV lesions was not uniform; there was a bright ring around the strong fluorescence. FAF found that active inflammatory lesions showed weak autofluorescence (AF), surrounded by a strong fluorescence ring; inactive inflammatory lesions showed AF loss. Secondary active CNV lesions showed strong AF with a bright ring along the edge, and obscured fluorescence for co-occurred hemorrhagic edema; secondary non-active CNV lesions were strong AF, surrounded by a weak AF ring. FFA revealed that active inflammatory lesions showed weak fluorescence in the early stage, and fluorescence gradually increased in the late stage with slight leakage. Inactive inflammatory lesions showed typical transmitted fluorescence. Fluorescein leakage secondary to active CNV was significant; lesions secondary to inactive CNV showed scar staining. In OCT, the active inflammatory lesions showed moderately weak reflex signals in the protruding lesions under the retinal pigment epithelium (RPE). The inactive inflammatory lesions showed penetrable RPE defects or choroidal scar, it also showed clear RPE uplift lesions with a strong reflection signal. Secondary active CNV showed subretinal fluid retention; secondary non-active CNV showed RPE defects and choroidal scarring. Conclusions Active inflammatory lesions in MFC have blurred boundary, retinal edema and fluorescein leakage in FFA; inactive inflammatory lesions have clear boundary and typical transmitted fluorescence in FFA, and no retinal edema. Secondary active CNV showed subretinal fluid in OCT; and secondary non-active CNV showed RPE defects and choroidal scarring.

    Release date:2018-01-17 03:16 Export PDF Favorites Scan
  • Research progress of optical coherence tomography angiography in retinal vein occlusion

    Retinal vein occlusion (RVO) is a vascular disease characterized by intraretinal hemorrhage, edema and hard exudation, which is caused by increased retinal vein pressure. OCT angiography (OCTA) has been widely used in the diagnosis of retinal vascular diseases including RVO by virtue of non-invasive, high resolution and stratified display of superficial, deep retinal vessels and quantification of retinal vessel density and non-perfusion area size. OCTA can provide information of retinal microvascular structure and blood perfusion under the condition of disease, it also can be used to evaluate the effect of treatment and changes of retinal circulation during the course of disease follow-up. Although OCTA cannot replace fundus angiography completely, it has brought us more information about the pathogenesis, disease progression and prognostic factors of RVO. It is believed that with the progress of technology, OCTA will bring us a new chapter in the study of retinal vascular diseases including RVO.

    Release date:2019-07-16 05:35 Export PDF Favorites Scan
  • Application of Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography in Patients with Pulmonary Tuberculosis

    Objective To assess the value of fluorine-18 fluorodeoxyglucose (18 F-FDG) positron emission tomography (PET) in patients with pulmonary tuberculosis. Methods Fifty-three patients with pulmonary tuberculosis were imaged with 18SF-FDG-PET. 18F-FDG-PET data were analyzed retrospectively with visual method and semiquantitative method. When pulmonary tuberculosis with abnormal 18F-FDG uptake appeared in PET scans confirmed by visual method, their maximum standard uptake value (SUVmax), mean standard uptake value (SUVmean) and standard uptake value of normal lung (SUVlung) were measured using semiquantitative method. Results Thirty-six pulmonary tuberculous nodules could be detected by 18SF- FDG-PET, and were diagnosed active tuberculosis with visual method. SUVmax(2. 77±1. 20) and SUV mean(2.15±0.86) were higher than SUVlung(0.41± 0.09, Z=-5. 232, P〈0.01 ; Z=- 5. 232, P〈0.01). Correlations were not found between SUVmax ,SUVmax and nodule size (Dmax, Dmin), SUVlung, age, blood glucose level in these 36 patients (P〉0.05). Seventeen fibrosis and calcification cases without caseous necrosis were not found abnormal in 18F-FDG-PET. Conclusion 18F- FDG- PET is useful in diagnosing active tuberculosis , extent of tuberculosis and guiding therapeutic regimen.

    Release date:2016-08-30 06:18 Export PDF Favorites Scan
  • Clinical evaluation and development trend of intraoperative optical coherence tomography in vitrectomy for fundus dieases

    With the increasing popularity of intraoperative optical coherence tomography (iOCT) equipment, the use of iOCT for a variety of fundus diseases is gradually increasing. Most clinical studies on iOCT have a small number of samples and lack of control, and the level and quality of evidence are generally not good. Therefore, the evaluation of the clinical value of iOCT is mainly based on whether it is helpful for surgical manipulation and whether it has influence on intraoperative decision-making. Currently, membrane peeling during vitrectomy is the most common use of iOCT. The current iOCT does not have the automatic tracking function, which requires the surgeon to stop the operation and manually adjust the position of the probe to track the scanning site to obtain the image. The synchronous automatic tracking cannot be achieved. In the future, it is necessary to develop an automatic tracking system to reduce the workload of the surgeon during the operation.

    Release date:2022-12-16 10:13 Export PDF Favorites Scan
  • Application of Micron Ⅳ retinal imaging system in three different types of mouse models

    ObjectiveTo evaluate Micron Ⅳ retinal imaging system in three mouse models of retinal diseases. MethodsMouse models of oxygen induced retinopathy (OIR) model (OIR group), N-methyl-N nitrosourea (MNU) model (MNU group) and N-methyl-D-aspartate (NMDA) model (NMDA group) were induced in 24 healthy male C57BL/6J mice. Fundus photograph, fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) and electroretinogram (ERG) were used to evaluate these mice. All the imaging examinations were performed by Micron Ⅳ retinal imaging system. ResultsOIR mice showed tortuous and dilated retinal vessels in fundus photograph, neovascularization plexus and vascular leakage in FFA, and epiretinal fibrovascular tissue and tortuous expansion vascular vessels in OCT. MNU mice showed wax yellow optic disk without retinal pigmentary changes, slight thinning of retinal blood vessels in FFA, and normal structure and thickness in OCT. The a-wave amplitudes of the maximum mixed response decreased significantly, and were (15.38±4.36) μV and (13.78±5.52) μV at 2 or 3 days of modeling, respectively. NMDA mice showed a pale retina with vasospasm. ERG revealed that there was no obvious change in latency of a- and b-wave, but significantly decreased amplitude of b-wave at 12 hours and 24 hours after modeling with (72.28±7.18) μV and (65.35±9.18) μV, respectively. ConclusionMicron Ⅳ retinal imaging system is a real-time, non-invasive tool to study the retinal structure and function in animal models of retinal diseases.

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  • Expanding the analysis of optical coherence tomography images

    Optical coherence tomography (OCT), as a high-resolution, non-invasive, in-vivo image method has been widely used in retinal field, especially in the examination of fundus diseases. Nowadays, the modality has been gradually popularized in most of the national basic-level hospitals. However, OCT is only employed as a diagnostic tool in most cases, ophthalmologists lack of awareness of further exploring the information behind the raw data. In the era of fast-developing artificial intelligence, on the basis of standardized information management, a more comprehensive OCT database should be established. Further original image processing, lesion analysis, and artificial intelligence development of OCT images will help improve the understanding level of vitreoretinal diseases among clinicians and assist ophthalmologists to make more appropriate clinical decisions.

    Release date:2022-12-16 10:13 Export PDF Favorites Scan
  • One year clinical results of different surgical methods in the treatment of idiopathic macular hole

    ObjectiveTo observe the effect of 25G pars plana vitrectomy (PPV) combined with or without internal limiting membrane (ILM) flap and sterile air or perfluoropropane (C3F8) tamponade in the treatment of idiopathic macular hole (IMH).MethodsA retrospective case analysis. From December 2015 to December 2016 in Tianjin Eye Hospital, 101 eyes of 98 consecutive IMH patients who underwent 25G PPV combined with or without ILM flap and sterile air or C3F8 tamponade, were included in this study. All patients underwent BCVA and OCT examination. The BCVA examination was performed using the international standard visual acuity chart, which was converted into logMAR visual acuity. The patients were divided into three groups according to preoperative minimum liner diameter of Hole (MLD) and surgical methods: MLD<400 μm for the group A, 41 eyes of 39 patients, MLD more than 400 μm without ILM flap surgery as the group B, 39 eyes of 38 patients, including 16 eyes tamponaded with air and 23 eyes tamponaded with C3F8, MLD more than 400 μm with ILM flap as the group C, a total of 21 patients of 21 eyes, including 7 eyes tamponaded with air and 14 eyes tamponaded with C3F8. The logMAR BCVA of group A, B and C were 0.82±0.39, 1.11±0.42, 1.25±0.50, respectively. The follow-up times were 1 week, 1 month, 3 month, 6 month and 1 year post operation, BCVA and OCT were performed at each follow-up time. The hole closure rate and BCVA improvement were observed.ResultsThe postoperative BCVA of group A, B and C was improved obviously, the differences were statistically significant (t=−11.66, −7.52, −4.99; P<0.01). There was no significant difference in improvement of visual acuity between the three groups (A and B, A and C, B and C group: t=0.77, −0.41, 0.28; P=0.44, 0.72, 0.76). 96.94% macular hole closure occurred in 7 days post operation. The postoperative visual acuity improved significantly in 3 mouth after operation,ConclusionsThe macular hole closure occurred mainly in 1 week after operation, postoperative visual acuity increased mostly in the 3rd month post operation. There is no advantage of ILM flap in improve postoperative visual acuity of IMH patients with MLD more than 400 μm.

    Release date:2020-01-11 10:26 Export PDF Favorites Scan
  • Spectral domain-optical coherence tomography analysis of choroid osteoma

    Objective To observe the image characteristics of eyes with choroidal osteoma using enhanced spectral domain optical Cirrus coherence tomography (SD-OCT), and to explore their relationship with visual acuity. Methods The records and SD-OCT images of 14 patients(18 eyes) diagnosed with choroidal osteoma at this hospital were reviewed retrospectively. All patients received examinations of best corrected visual acuity (BCVA), direct or indirect ophthalmoscope, slit lamp ophthalmoscope, fundus fluorescein angiography, B scan and/or computerized tomography. Subtle structure changes of the retina and choroidal osteoma were observed by four lines of the horizontal, the vertical scanning lines through the foveal and the tumor basal diameter under the model of five Line Raster.The correlation between the retinal and choroidal morphology and visual acuity was evaluated. Results The choroidal features of SD-OCT image of choroidal osteoma can be categorized into hyper-reflective in six eyes (33.3%), isoreflective in five eyes (27.8%), hypo-reflective in three eyes (16.7%) and mixing-reflective in four eyes (22.2%). The foveal thickness ranged from 50.2 to 245.1μm, and the average foveal thickness was (130.2±58.3) μm. The horizontal and vertical diameters of choroidal osteoma ranged from 5.6 to 15.8 mm and 4.6 to 12.8 mm respectively. The average horizontal and vertical diameters of choroidal osteoma were (7.8±2.9) mm and (6.5±2.5) mm respectively. The statistical analysis revealed that BCVA was not related to the horizontal, vertical diameters of choroidal osteoma or the foveal thickness (r=0.262, 0.229, 0.137; P=0.284, 0.294, 0.362). BCVA was related to the involvement of fovea and the integrity of photoreceptor inner/outer segment junction (IS/OS) (r=-3.838,-4.559; P=0.0015, 0.0003),but not related to macular choroidal neovascularization (CNV) or serous retinal detachment (r=-0.144, 0.411; P=0.684, 0.687). Conclusions The main SD-OCT image characteristics of eyes with choroidal osteoma was hyper-reflective and isoreflective. BCVA was not related to the horizontal, the vertical diameters of choroidal osteoma, the foveal thickness, macular CNV or serous retinal detachment. It was related to the involvement of fovea and the integrity of IS/OS.

    Release date:2016-09-02 05:22 Export PDF Favorites Scan
  • Acute zonal occult outer retinopathy

    Acute zonal occult outer retinopathy (AZOOR) is an acquired retinal diseases. The majority of patients who develop AZOOR are women characterized by an acute onset of visual blurred and scotoma with photopsias. The fundus examination is often normal or appeared mild abnormal. The RPE atrophy of fundus is similar with white syndrome. Although FFA and ICGA features are either unremarkable or unrelated to AZOOR, there are still important in differential diagnosis. The characteristic abnormalities appearance of FAF (complicated and varied), OCT (regional anomaly of ellipsoid zone), visual field (visual field defect) and ERG (decreased amplitude and prolonged latency of rod reaction, maximum reaction, cone reaction and scintillation reaction) are considered critical examinations to the diagnosis of AZOOR. Although there is no effective therapy for AZOOR, it has some self-limitation.

    Release date:2019-05-17 04:15 Export PDF Favorites Scan
  • Advances in the clinical application of optical coherence tomography angiography in glaucoma

    As a neurodegenerative disease of the retina, glaucoma can cause irreversible vision loss in patients. More and more evidences indicate that systemic blood flow abnormalities, decreased optic nerve blood flow, and retinal microcirculation disorders are related to the mechanism of glaucoma ganglion injury. Optical coherence tomography (OCTA) has the advantages of non-invasive, high resolution, quick inspection, three-dimensional imaging, and quantitative blood flow perfusion. Compared with other blood flow detection methods such as color ultrasound Doppler, laser speckle blood flow imaging, etc. it has higher performance and accuracy, and is easier to be applied in clinical practice. OCTA can not only be used for the early diagnosis and follow-up of glaucoma, but has a strong correlation with retinal nerve fiber layer thickness and visual field parameters; it can also provide objective data for the follow-up of patients with advanced glaucoma to assess the progress of the disease. In the future, OCTA is expected to become a routine detection method and follow-up method for the diagnosis of glaucoma.

    Release date:2021-07-21 02:11 Export PDF Favorites Scan
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