scholarly journals Automated segmentation and fractal analysis of high-resolution non-invasive capillary perfusion maps of the human retina

2013 ◽  
Vol 89 ◽  
pp. 172-175 ◽  
Author(s):  
Hong Jiang ◽  
Delia Cabrera DeBuc ◽  
Tatjana Rundek ◽  
Byron L. Lam ◽  
Clinton B. Wright ◽  
...  
Keyword(s):  
High Resolution ◽  
Fractal Analysis ◽  
Automated Segmentation ◽  
Human Retina ◽  
Capillary Perfusion ◽  
Non Invasive ◽  
Perfusion Maps

scholarly journals Retinal functional imager (RFI): Non-invasive functional imaging of the retina

2013 ◽  
Vol 5 (2) ◽  
pp. 250-257 ◽  
Author(s):  
Sunil Ganekal
Keyword(s):  
Functional Imaging ◽  
Structural Changes ◽  
Imaging System ◽  
Retinal Blood Flow ◽  
Capillary Perfusion ◽  
Functional Changes ◽  
Non Invasive ◽  
Retinal Disorders ◽  
Retinal Blood Flow Velocity ◽  
Perfusion Maps

Retinal functional imager (RFI) is a unique non-invasive functional imaging system with novel capabilities for visualizing the retina. The objective of this review was to show the utility of non-invasive functional imaging in various disorders. Electronic literature search was carried out using the websites www.pubmed.gov and www.google.com. The search words were retinal functional imager and non-invasive retinal imaging used in combination. The articles published or translated into English were studied. The RFI directly measures hemodynamic parameters such as retinal blood-flow velocity, oximetric state, metabolic responses to photic activation and generates capillary perfusion maps (CPM) that provides retinal vasculature detail similar to flourescein angiography. All of these parameters stand in a direct relationship to the function and therefore the health of the retina, and are known to be degraded in the course of retinal diseases. Detecting changes in retinal function aid early diagnosis and treatment as functional changes often precede structural changes in many retinal disorders. Nepal J Ophthalmol 2013; 5(10): 250-257 DOI: http://dx.doi.org/10.3126/nepjoph.v5i2.8738

scholarly journals Exploratory study of non-invasive, high-resolution functional macular imaging in subjects with diabetic retinopathy

2021 ◽  
Vol 14 (1) ◽  
pp. 57-63
Author(s):  
Thalmon R Campagnoli ◽  
◽  
Jing Tian ◽  
Delia Cabrera DeBuc ◽  
William E. Smiddy ◽  
...  
Keyword(s):  
Blood Flow ◽  
Diabetic Retinopathy ◽  
High Resolution ◽  
Functional Imaging ◽  
Case Series ◽  
Diabetic Patients ◽  
Capillary Perfusion ◽  
Imaging Device ◽  
Non Invasive ◽  
Retinal Microvasculature

AIM: To evaluate a high-resolution functional imaging device that yields quantitative data regarding macular blood flow and capillary network features in eyes with diabetic retinopathy (DR). METHODS: Prospective, cross-sectional comparative case-series in which blood flow velocities (BFVs) and non-invasive capillary perfusion maps (nCPMs) in macular vessels were measured in patients with DR and in healthy controls using the Retinal Functional Imager (RFI) device. RESULTS: A total of 27 eyes of 21 subjects were studied [9 eyes nonproliferative diabetic retinopathy (NPDR), 9 eyes proliferative diabetic retinopathy (PDR) and 9 controls]. All diabetic patients were type 2. All patients with NPDR and 5 eyes with PDR also had diabetic macular edema (DME). The NPDR group included eyes with severe (n=3) and moderate NPDR (n=6), and were symptomatic. A significant decrease in venular BFVs was observed in the macular region of PDR eyes when compared to controls (2.61±0.6 mm/s and 2.92±0.72 mm/s in PDR and controls, respectively, P=0.019) as well as PDR eyes with DME compared to NPDR eyes (2.36±0.51 mm/s and 2.94±1.09 mm/s in PDR with DME and NPDR, respectively, P=0.01). CONCLUSION: The RFI, a non-invasive imaging tool, provides high-resolution functional imaging of the retinal microvasculature and quantitative measurement of BFVs in visually impaired DR patients. The isolated diminish venular BFVs in PDR eyes compared to healthy eyes and PDR eyes with DME in comparison to NPDR eyes may indicate the possibility of more retinal vein compromise than suspected in advanced DR.

scholarly journals High resolution Physio-chemical Tissue Analysis: Towards Non-invasive In Vivo Biopsy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Guan Xu ◽  
Zhuo-xian Meng ◽  
Jian-die Lin ◽  
Cheri X. Deng ◽  
Paul L. Carson ◽  
...  
Keyword(s):  
High Resolution ◽  
Tissue Analysis ◽  
Non Invasive

scholarly journals Non-invasive assessment of vasospasm following aneurysmal SAH using C-arm FDCT parenchymal blood volume measurement in the neuro-interventional suite: Technical feasibility

2015 ◽  
Vol 21 (4) ◽  
pp. 479-489 ◽  
Author(s):  
Mudassar Kamran ◽  
Jonathan Downer ◽  
Rufus Corkill ◽  
James V Byrne
Keyword(s):  
Blood Volume ◽  
Objective Assessment ◽  
Transcranial Doppler Sonography ◽  
Aneurysmal Subarachnoid Haemorrhage ◽  
Mr Perfusion ◽  
Treatment Unit ◽  
Non Invasive ◽  
Major Vessel ◽  
Parenchymal Blood Volume ◽  
Perfusion Maps

Introduction Cerebral vasospasm is the leading cause of morbidity and mortality in patients with aneurysmal subarachnoid haemorrhage (SAH) surviving the initial ictus. Commonly used techniques for vasospasm assessment are digital subtraction angiography and transcranial Doppler sonography. These techniques can reliably identify only the major vessel spasm and fail to estimate its haemodynamic significance. To overcome these issues and to enable comprehensive non-invasive assessment of vasospasm inside the interventional suite, a novel protocol involving measurement of parenchymal blood volume (PBV) using C-arm flat detector computed tomography (FDCT) was implemented. Materials and methods Patients from the neuro-intensive treatment unit (ITU) with suspected vasospasm following aneurysmal SAH were scanned with a biplane C-arm angiography system using an intravenous contrast injection protocol. The PBV maps were generated using prototype software. Contemporaneous clinically indicated MR scan including the diffusion- and perfusion-weighted sequences was performed. C-arm PBV maps were compared against the MR perfusion maps. Results Distribution of haemodynamic impairment on C-arm PBV maps closely matched the pattern of abnormality on MR perfusion maps. On visual comparison between the two techniques, the extent of abnormality indicated PBV to be both cerebral blood flow and cerebral blood volume weighted. Conclusion C-arm FDCT PBV measurements allow an objective assessment of the severity and localisation of cerebral hypoperfusion resulting from vasospasm. The technique has proved feasible and useful in very sick patients after aneurysmal SAH. The promise shown in this early study indicates that it deserves further evaluation both for post-SAH vasospasm and in other relevant clinical settings.

Visualization of USPIO-Labeled Melt-Electrowritten Scaffolds by Non-Invasive Magnetic Resonance Imaging

2021 ◽  
Author(s):  
Kilian Maria Arthur Mueller ◽  
Geoffrey Topping ◽  
Sebastian Patrick Schwaminger ◽  
Younzhe Zou ◽  
Diana Marcela Rojas-González ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Tissue Engineering ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Digital Fabrication ◽  
Resonance Imaging ◽  
Non Invasive ◽  
Forming Technology

Melt electrowriting (MEW) is a high-resolution fiber-forming technology for the digital fabrication of complex micro-structured scaffolds for tissue engineering, which has convincingly shown its potential in in vitro and in...

scholarly journals Fractal Dimension Analysis of High-Resolution X-Ray Phase Contrast Micro-Tomography Images at Different Threshold Levels in a Mouse Spinal Cord

2018 ◽  
Vol 3 (4) ◽  
pp. 48 ◽  
Author(s):  
Laura Maugeri ◽  
Mauro DiNuzzo ◽  
Marta Moraschi ◽  
Charles Nicaise ◽  
Inna Bukreeva ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Fractal Dimension ◽  
High Resolution ◽  
Fractal Analysis ◽  
Phase Contrast ◽  
Threshold Level ◽  
Mouse Spinal Cord ◽  
X Ray ◽  
Threshold Levels ◽  
Micro Tomography

Fractal analysis is a powerful method for the morphological study of complex systems that is increasingly applied to biomedical images. Spatial resolution and image segmentation are crucial for the discrimination of tissue structures at the multiscale level. In this work, we have applied fractal analysis to high-resolution X-ray phase contrast micro-tomography (XrPCμT) images in both uninjured and injured tissue of a mouse spinal cord. We estimated the fractal dimension (FD) using the box-counting method on tomographic slices segmented at different threshold levels. We observed an increased FD in the ipsilateral injured hemicord compared with the contralateral uninjured tissue, which was almost independent of the chosen threshold. Moreover, we found that images exhibited the highest fractality close to the global histogram threshold level. Finally, we showed that the FD estimate largely depends on the image histogram regardless of tissue appearance. Our results demonstrate that the pre-processing of XrPCμT images is critical to fractal analysis and the estimation of FD.

scholarly journals Ultrasound - first imaging modality in the detection of parathyroid adenomas

2008 ◽  
Vol 12 (3) ◽  
pp. 64 ◽  
Author(s):  
R Ahmed ◽  
N Khan ◽  
S Ellemdin ◽  
K Gayaparsad
Keyword(s):  
Nuclear Medicine ◽  
High Resolution ◽  
Gold Standard ◽  
Imaging Modality ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Parathyroid Adenomas ◽  
Thyroid Adenomas ◽  
Invasive Method ◽  
Ultrasound Features

Abstract We present a series of 12 patients in whom the typical ultrasound features of parathyroid adenomas were accurately demonstrated. High resolution ultrasound [in experienced hands] is a highly sensitive accurate, safe and non invasive method of localizing parathyroid adenomas especially in patients with typically located glands and an absence of thyroid pathology. Our aim was to compare ultrasound with nuclear medicine as an imaging gold standard in patients with thyroid adenomas.

scholarly journals High-resolution analysis of the human retina miRNome reveals isomiR variations and novel microRNAs

2016 ◽  
Vol 44 (4) ◽  
pp. 1525-1540 ◽  
Author(s):  
Marianthi Karali ◽  
Maria Persico ◽  
Margherita Mutarelli ◽  
Annamaria Carissimo ◽  
Mariateresa Pizzo ◽  
...  
Keyword(s):  
High Resolution ◽  
Human Retina ◽  
High Resolution Analysis ◽  
Resolution Analysis
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