Search results for "tomography"
showing 10 items of 2332 documents
Vascular changes after vitrectomy for rhegmatogenous retinal detachment: optical coherence tomography angiography study
2020
Purpose: To analyse the postoperative foveal avascular zone (FAZ) area, superficial vessel density (SVD) and deep vessel density (DVD) and their correlation with functional (best-corrected visual acuity, BCVA) and anatomical outcomes (foveal macular thickness, FMT) after surgery for rhegmatogenous retinal detachment (RRD) repair. Method: Patients with RRD eyes, successfully treated with a single pars plana vitrectomy (PPV) with gas tamponade and a minimum 12 months follow-up, were re-examined. Foveal avascular zone (FAZ) area, SVD, DVD and FMT were evaluated by using optical coherence tomography angiography (OCTA) and compared to fellow eye. Results: Fifty-six patients with macula-on and 37…
C21orf2 is mutated in recessive early-onset retinal dystrophy with macular staphyloma and encodes a protein that localises to the photoreceptor prima…
2015
Background/aim We have noted a phenotype of early-onset retinal dystrophy with macular staphyloma but without high myopia. The aim of this study is to report the underlying genetic mutations and the subcellular localisation of the gene product in the retina. Methods Retrospective case series (2012–2015); immunohistochemical analyses of mammalian retina for in situ protein localisation. Results All three probands were first noted to have decreased vision at 3–6 years old which worsened over time. At ages 39, 37 and 12 years old, all had similar retinal findings: dystrophic changes (retinal pigment epithelium mottling, vessel narrowing), macular staphyloma (despite only mild myopia or high hy…
Impact of medical imaging on the epigenome – low-dose exposure in the course of computed tomography does not induce detectable changes of DNA-methyla…
2021
Computed tomography (CT) is a main contributor to artificial low-dose exposure. Understanding the biological effects induced by CT exposure and their dependency on the characteristics of photon spectra is essential for knowledge-driven risk assessment. In a previous gene expression study, we have identified upregulation of AEN, BAX, DDB2, EDA2R and FDXR after ex vivo exposure with single-energy CT and dual-energy CT (DECT). In this study, we focused on CT-induced changes of DNA methylation. This epigenetic modification of DNA is a central regulator of gene expression and instrumental in preserving genome integrity. Previous studies reported focal hypermethylation and global hypomethylation …
Sprouting and intussusceptive angiogenesis in postpneumonectomy lung growth: mechanisms of alveolar neovascularization
2013
In most rodents and some other mammals, the removal of one lung results in compensatory growth associated with dramatic angiogenesis and complete restoration of lung capacity. One pivotal mechanism in neoalveolarization is neovascularization, because without angiogenesis new alveoli can not be formed. The aim of this study is to image and analyze three-dimensionally the different patterns of neovascularization seen following pneumonectomy in mice on a sub-micron-scale. C57/BL6 mice underwent a left-sided pneumonectomy. Lungs were harvested at various timepoints after pneumonectomy. Volume analysis by microCT revealed a striking increase of 143 percent in the cardiac lobe 14 days after pneum…
Fibropolycystic Liver Disease: CT and MR Imaging Findings
2005
Fibropolycystic liver disease encompasses a spectrum of related lesions of the liver and biliary tract that are caused by abnormal embryologic development of the ductal plates. These lesions (congenital hepatic fibrosis, biliary hamartomas, autosomal dominant polycystic disease, Caroli disease, choledochal cysts) can be clinically silent or can cause signs and symptoms such as cholangitis, portal hypertension, gastrointestinal bleeding, infections, and space-occupying masses. The different types of fibropolycystic liver disease demonstrate characteristic findings at computed tomography (CT) and magnetic resonance (MR) imaging. Patients with congenital hepatic fibrosis typically have imaging…
18F-fluorodeoxyglucose hypometabolism in cerebellar tonsil and flocculus in downbeat nystagmus.
2006
A patient with downbeat nystagmus was examined by F-fluorodeoxyglucose-positron emission tomography once while off and twice while on successful treatment with 4-aminopyridine. All positron emission tomography scans of the patient showed a reduced cerebral glucose metabolism bilaterally in the region of the cerebellar tonsil and flocculus/paraflocculus when compared with a normal database of the whole brain. An additional region-of-interest analysis revealed that 4-aminopyridine treatment lessened the hypometabolism. This finding supports the hypothesis that the cerebellar tonsil and (para-) flocculus play a crucial role in downbeat nystagmus. The hypometabolism might reflect reduced inhibi…
Chromoendoscopy and Other Novel Imaging Techniques
2006
The newly developed high-resolution and magnification endoscopes offer features that allow more and new mucosal details to be seen. They are commonly used in conjunction with chromoendoscopy. The analysis of mucosal surface details is beginning to resemble histologic examination. More accurate recognition of small flat and depressed neoplastic lesions is possible. Endoscopic prediction of neoplastic and nonneoplastic tissue is possible by analysis of surface architecture of the mucosa, which influences the endoscopic management. For the diagnosis of flat adenomas, chromoendoscopy should be a part of the endoscopist's armamentarium. In inflammatory bowel disease, chromoendoscopy can be used …
Association between maxillary sinus pathology and odontogenic lesions in patients evaluated by cone beam computed tomography. A systematic review and…
2019
Background A study is made of the association between maxillary sinus pathology and odontogenic lesions in patients evaluated with cone beam computed tomography. Material and Methods A literature search was made in five databases and OpenGrey. Methodological assessment was carried out using the Newcastle-Ottawa tool for observational studies. The random-effects model was used for the meta-analysis. Results Twenty-one studies were included in the qualitative review and 6 in the meta-analysis. Most presented moderate or low risk of bias. The periodontal disease showed to be associated with the thickening of the sinus membrane (TSM). Mucous retention cysts and opacities were reported in few st…
Castleman's disease presenting as fever of unknown origin: diagnostic value of fluorodeoxyglucose-positron emission tomography/computed tomography.
2009
Abstract: Castleman's disease is an uncommon lymphoproliferative disorder that can present in both nodal and extranodal sites. The cause is unknown, but a disordered immunoregulation, which results in the excessive proliferation of B lymphocytes and plasma cells in lymphoid organs, plays a central role in the development of the condition. Three distinct histologic types (hyaline vascular, plasma cell, and mixed), and 2 anatomical variants (localized and multicentric) have been described. Clinical presentation generally consists of enlargement of lymph nodes or other tissues, fever, asthenia, weight loss, and other general symptoms, associated with nonspecific blood analysis abnormalities, s…
Utility of imaging techniques in the diagnosis of oral cancer.
2015
Abstract Purpose Imaging techniques such as magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET) are often used to complement the clinical exploration and staging of oral squamous cell carcinoma (OSCC). Which of these techniques is best in establishing correct staging and treatment planning is not clear, however. This study aims to determine which technique is most appropriate for diagnosing the primary tumor and for detecting bone invasion and neck metastases. Material and methods A Medline literature search was made over the last 10 years. In each selected study, we recorded the sample size and sensitivity, specificity and precision. Strengths…