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Positron emission tomography/computed tomography outperforms MRI in the diagnosis of local recurrence and residue of nasopharyngeal carcinoma: An update evidence from 44 studies
摘要： Studies on nasopharyngeal carcinoma (NPC) in five electronic databases were systematically searched online from the inception to June 5, 2018. Quality of the included studies was assessed using the updated Quality Assessment of Diagnostic Accuracy Studies 2. Data of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the 95% confidence intervals were pooled using a bivariate random‐effect model. Forty‐four studies with 61 groups of data and totally 3369 patients were included in the qualitative and quantitative synthesis analysis. The overall estimated sensitivity and specificity of positron emission tomography/computed tomography/magnetic resonance imaging (PET‐CT/MRI) for local recurrent/residual NPC were 0.90 and 0.85, respectively. The pooled area under the curve of (AUC) of PET‐CT/MRI in the summary receiver operator characteristic curve was 0.94. Subgroup analysis showed MRI vs PET‐CT had lower sensitivity (0.83 vs 0.92) and specificity (0.78 vs 0.89). The AUCs of MRI and PET‐CT were 0.87 and 0.96, respectively. No‐cross of 95% CI was found in MRI vs PET/CT (0.87‐0.90 vs 0.94‐0.98). Meta‐regression showed PET/CT vs MRI was a potential source of heterogeneity. PET/CT and MRI both showed quite high overall ability in diagnosing local recurrent/residual NPC, but the subgroup analysis indicated PET‐CT was superior over MRI in diagnosis of local recurrence and residue of NPC after radiotherapy. The examination methods affected the heterogeneity within studies.
关键词： specificity,positron emission tomography/computed tomography,sensitivity,magnetic resonance imaging,recurrence/residue,nasopharyngeal carcinoma
更新于2025-09-23 15:23:52
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A novel alignment procedure to assess calcified coronary plaques in histopathology, post-mortem computed tomography angiography and optical coherence tomography
摘要： Purpose: Improve mapping and registration of longitudinal view on histopathology vessels in a three-dimensional alignment procedure for postmortem quantitative coronary plaque analyses. This new procedure is applied and results shown using calcified coronary plaque analyses within post-mortem computed tomography angiography (PMCTA), optical coherence tomography (OCT) and the gold standard of histopathology. Results: In total, 338 annotated histopathology images were included, 166 PMCTA transversal images and 285 OCT images were aligned in the comparison. The results from the comparison using the alignment procedure showed overall that the calcified plaques seem to be overestimated by PMCTA and underestimated by OCT. Conclusions: The 3D fusion approach, aligning the images of PMCTA, OCT and histopathology as gold standard allowed for a slice-based comparison of the different modalities. The results showed that PMCTA overestimates the calcified plaques while OCT underestimates these, compared to histopathology.
关键词： Alignment,Calcified coronary plaques,Histopathology,Optical coherence tomography,Postmortem-computed tomography angiography
更新于2025-09-23 15:23:52
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Multimodal imaging and treatment of Purtscher-like retinopathy
摘要： A 52-year-old patient with multiple cardiovascular risk factors referred for unilateral, acute, and painless visual loss. In the fundoscopic image there was significant papillary inflammation with tortuosity at this level and hemorrhages. Ophthalmological examination showed papillary inflammation, macular edema, and involvement in retinal inner layers. The control fluorescein angiography and optical coherence tomography angiography showed areas of central and peripheral ischemia. Given the clinical findings and background of the patient, the diagnosis of Purtscher-like retinopathy was reached and treatment with intravitreal dexamethasone was decided. Purtscher-like retinopathy is a rare entity that occurs in patients with multiple systemic pathologies, but without a traumatic background, which differentiates it from Purstcher's retinopathy. The diagnosis and early intervention are important in the prognosis. There are no therapeutic protocols, but good results have been obtained with intravitreal therapy with dexamethasone.
关键词： Purtscher flecken,Purtscher-like retinopathy,Purtscher retinopathy,Optical coherence tomography angiography,Optical coherence tomography
更新于2025-09-23 15:23:52
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Optische Koh?renztomografie
摘要： With telematics and technologies like “Digital Impression”, “CAD/CAM” or “3D-radiography” the digitalization has reached the dental practice by now. The desire for more efficient diagnostics is especially addressed by 3D-radiography. A noninvasive imaging technology with a considerable diagnostic potential is the optical coherence tomography. In this article, promising examples of OCT use in operative dentistry are presented that raise expectations of a wide range of applications of this innovative technology in dentistry.
关键词： restoration assessment,caries diagnosis,optical coherence tomography,restorative therapy with composite,monitoring,tomography
更新于2025-09-23 15:23:52
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Initial evaluation of <scp>PET</scp> / <scp>CT</scp> with <sup>18</sup> F‐ <scp>FSU</scp> ‐880 targeting prostate‐specific membrane antigen in prostate cancer patients
摘要： This first-in-man study was carried out to evaluate the safety, whole-body distribution, dose estimation, and lesion accumulation of 18F-FSU-880, a newly developed probe targeting prostate-specific membrane antigen. Six prostate cancer patients with known metastatic lesions underwent serial whole-body PET/computed tomography (CT) with 18F-FSU-880. Blood and urine were analyzed before and after PET/CT. Accumulation of 18F-FSU-880 in organs and metastatic lesions in serial PET images were evaluated by measuring the standardized uptake values. From the biodistribution data, the organ doses and whole-body effective dose were calculated using OLINDA/EXM software. 18F-FSU-880 PET/CT could be carried out without significant adverse effects. High physiological uptake was observed in the salivary/lachrymal glands and kidneys. The effective dose was calculated to be 0.921 × 10?2 mSv/MBq. Known metastatic lesions were clearly visualized with high image contrast that increased with time, except in 1 patient, whose bone metastases were well-controlled and inactive. The PET/CT with 18F-FSU-880 could be carried out safely and could clearly visualize active metastatic lesions. The present results warrant further clinical studies with a larger number of cases to verify the clinical utility of 18F-FSU-880 PET/CT in the management of prostate cancer patients.
关键词： dosimetry,prostate cancer,prostate-specific membrane antigen,positron emission tomography/computed tomography,fluorine-18
更新于2025-09-23 15:23:52
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A mathematical model and iterative inversion for fluorescent optical projection tomography
摘要： Solving the fluorophore distribution in a tomographic setting has been difficult because of the lack of physically meaningful and computationally applicable propagation models. This study concentrates on the direct modelling of fluorescence signals in optical projection tomography (OPT), and on the corresponding inverse problem. The reconstruction problem is solved using emission projections corresponding to a series of rotational imaging positions of the sample. Similarly to the bright field OPT bearing resemblance with the transmission X-ray computed tomography, the fluorescent mode OPT is analogous to X-ray fluorescence tomography (XFCT). As an improved direct model for the fluorescent OPT, we derive a weighted Radon transform based on the XFCT literature. Moreover, we propose a simple and fast iteration scheme for the slice-wise reconstruction of the sample. The developed methods are applied in both numerical experiments and inversion of fluorescent OPT data from a zebrafish embryo. The results demonstrate the importance of propagation modelling and our analysis provides a flexible modelling framework for fluorescent OPT that can easily be modified to adapt to different imaging setups.
关键词： weighted Radon transform,optical projection tomography,fluorescence tomography,beam modelling,iterative reconstruction
更新于2025-09-23 15:23:52
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Spectral correction for handheld optoacoustic imaging by means of near-infrared optical tomography in reflection mode
摘要： In vivo imaging of tissue/vasculature oxygen saturation levels is of prime interest in many clinical applications. To this end, the feasibility of combining two distinct and complementary imaging modalities was investigated: optoacoustics (OA) and near-infrared tomography (NIROT), both operating noninvasively in reflection mode. Experiments were conducted on two optically heterogeneous phantoms mimicking tissue before and after the occurrence of a perturbation. OA imaging was used to resolve submillimetric vessel-like optical absorbers at depths up to 25 mm, but with a spectral distortion in the OA signals. NIROT measurements were utilized to image perturbations in the background and to estimate the light fluence inside the phantoms at the wavelength pair (760 nm, 830 nm). This enabled the spectral correction of the vessel-like absorbers' OA signals: the error in the ratio of the absorption coefficient at 830 nm to that at 760 nm was reduced from 60%-150% to 10%-20%. The results suggest that oxygen saturation (SO2) levels in arteries can be determined with <10% error and furthermore, that relative changes in vessels' SO2 can be monitored with even better accuracy. The outcome relies on a proper identification of the OA signals emanating from the studied vessels.
关键词： fluence compensation,near-infrared optical tomography,blood oxygen saturation,quantitative optoacoustic imaging,optoacoustic signal quantification,multimodal imaging,spectral correction
更新于2025-09-23 15:23:52
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Characterization of Abnormal Optic Nerve Head Morphology in Albinism Using Optical Coherence Tomography
摘要： PURPOSE. To characterize abnormalities in three-dimensional optic nerve head (ONH) morphology in people with albinism (PWA) using spectral-domain optical coherence tomography (SD-OCT) and to determine whether ONH abnormalities relate to other retinal and clinical abnormalities. METHODS. Spectral-domain OCT was used to obtain three-dimensional images from 56 PWA and 60 age- and sex-matched control subjects. B-scans were corrected for nystagmus-associated motion artefacts. Disc, cup, and rim ONH dimensions and peripapillary retinal nerve fiber layer (ppRNFL) thickness were calculated using Copernicus and ImageJ software. RESULTS. Median disc areas were similar in PWA (median ? 1.65 mm2) and controls (1.71 mm2, P ? 0.128), although discs were significantly elongated horizontally in PWA (P < 0.001). In contrast, median optic cup area in PWA (0.088 mm2) was 23.7% of that in controls (0.373 mm2, P < 0.001), with 39.4% of eyes in PWA not demonstrating a measurable optic cup. This led to significantly smaller cup to disc ratios in PWA (P < 0.001). Median rim volume in PWA (0.273 mm3) was 136.6% of that in controls (0.200 mm3). The ppRNFL was significantly thinner in PWA compared with controls (P < 0.001), especially in the temporal quadrant. In PWA, ppRNFL thickness was correlated to ganglion cell thickness at the central fovea (P ? 0.007). Several ONH abnormalities, such as cup to disc ratio, were related to higher refractive errors in PWA. CONCLUSIONS. In PWA, ocular maldevelopment is not just limited to the retina but also involves the ONH. Reduced ppRNFL thickness is consistent with previous reports of reduced ganglion cell numbers in PWA. The thicker rim volumes may be a result of incomplete maturation of the ONH.
关键词： albinism,optic nerve head,optical coherence tomography
更新于2025-09-23 15:23:52
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Retinal vascular density evaluated by optical coherence tomography angiography in macular telangiectasia type 2
摘要： Purpose To evaluate the retinal and choroidal vascular changes through optical coherence tomography angiography (OCTA) in patients with macular telangiectasia type 2 (MacTel 2). Methods Our study included 20 patients (40 eyes) with MacTel 2, and age-matched and sex-matched 18 subjects (36 eyes) in the control group. Fundus color photographs, fundus autofluorescence, fundus fluorescein angiography, spectral-domain optical coherence tomography and OCTA were performed. Foveal vascular density and parafoveal vascular density (PFVD), and foveal retinal thickness and parafoveal retinal thickness, choroidal thickness (CT) and retinal ganglion cell–inner plexiform layer (GCIPL) were compared between MacTel 2 patients and normal age-matched controls. Results The retinal whole vascular density and PFVD of the deep plexus were significantly lower in patients with MacTel 2 than that of the control group (56.93% vs. 58.54%, p = 0.003; and 60.38% vs. 61.66%, p = 0.045). The foveal avascular zone (FAZ) of the deep plexus was significantly enlarged in patients with MacTel 2 than that of the control group (0.44 vs. 0.36, p = 0.009). There was a positive and statistically significant correlation between the FAZ of the superficial and deep plexus and CT in patients with MacTel 2. There was a positive and statistically significant correlation between retinal whole, parafoveal temporal quadrant vascular density of the superficial and deep plexus and GCIPL thickness in patients with MacTel 2. Conclusions Our study demonstrated that important retinal vascular density and FAZ changes in MacTel 2 occur in the deep capillary plexus of the retina.
关键词： Macular telangiectasia type 2,Vascular density,Choroidal thickness,Retinal ganglion cell–inner plexiform layer,Optical coherence tomography angiography
更新于2025-09-23 15:23:52
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Non-ionized, High-resolution Measurement of Internal and Marginal Discrepancies of Dental Prosthesis Using Optical Coherence Tomography
摘要： An internal and marginal fit between prosthesis and abutment are important factors of the durability of dental prosthesis. In this study we have proposed the use of swept-source optical coherence tomography (SS-OCT) as a novel application for non-ionized and high-resolution measurements of internal and marginal discrepancies at anatomically critical four points, such as occlusal, angle, axial, and margin during prosthesis attachment. A tooth model was fabricated by 3D printing technique and the dental prosthesis was designed using dental CAD software. The cross-sectional images along with intensity peak profile analysis of the sample were acquired using OCT system for measurements of fit. The demonstrated qualitative and quantitative evaluations can be well-utilized for assessment of the internal and marginal fit of dental prosthesis.
关键词： Intensity analysis,Dental prosthesis,Internal and marginal fit,Swept-source optical coherence tomography
更新于2025-09-23 15:23:52