Optical projection tomography Dotaz Zobrazit nápovědu
The general microscopic characteristics of nerves are described in several textbooks of histology, but the specific microanatomies of most nerves that can be blocked by anesthesiologists are usually less well known. Our objective was to evaluate the 3D reconstruction of nerve fascicles from optical projection tomography images (OPT) and the ability to undertake an internal navigation exploring the morphology in detail, more specifically the fascicular interconnections. Median and lingual nerve samples were obtained from five euthanized piglets. OPT images of the samples were acquired and 3D reconstruction was performed. The OPT technique revealed the inner structure of the nerves at high resolution, including large and small fascicles, perineurium, interfascicular tissue, and epineurium. The fascicles were loosely packed inside the median nerve and more densely so in the lingual nerve. Analysis of the 3D models demonstrated that the nerve fascicles can show six general spatial patterns. Fascicular interconnections were clearly identified. The 3D reconstruction of nerve fascicles from OPT images opens a new path for research into the microstructure of the inner contents of fascicular nerve groups and their spatial disposition within the nerve including their interconnections. These techniques enable 3D images of partial areas of nerves to be produced and could became an excellent tool for obtaining data concerning the 3D microanatomy of nerves, essential for better interpretation of ultrasound images in clinical practice and thus avoiding possible neurological complications. Clin. Anat. 31:424-431, 2018. © 2017 Wiley Periodicals, Inc.
- Klíčová slova
- 3D reconstructions, fascicles, optical projection tomography, peripheral nerve,
- MeSH
- lidé MeSH
- optická tomografie MeSH
- periferní nervy diagnostické zobrazování MeSH
- zobrazování trojrozměrné metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
The examination of nerve microarchitecture has hitherto been limited solely to two-dimensional imaging techniques. The objective of this study was to evaluate the ability of optical projection tomography to discern the nerve microarchitecture and injection injury in three dimensions. Five piglets were studied, whose median and lingual nerves were unilaterally injected post mortem with preset volumes of local anaesthetic, excised and subsequently made transparent with benzyl alcohol benzyl benzoate. Images were captured in three dimensions. The same contralateral nerves were used as controls. Using optical projection tomography, we observed differences between the internal organisation of the median and the lingual nerves, which potentially explain the variations in their susceptibility to injury. This was demonstrated in three dimensions as a disruption to the fascicles in the lingual nerve, and their displacement in the median nerve. This new technology offers potential for studying nerve microarchitecture topography and its tolerance to injection injury.
- MeSH
- anestetika lokální aplikace a dávkování MeSH
- fluorescence MeSH
- nervová blokáda škodlivé účinky MeSH
- nervus lingualis diagnostické zobrazování MeSH
- nervus medianus diagnostické zobrazování zranění MeSH
- optická tomografie * MeSH
- poranění nervus lingualis diagnostické zobrazování etiologie MeSH
- prasata MeSH
- rentgendiagnostika MeSH
- zobrazování trojrozměrné * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- anestetika lokální MeSH
Optical projection tomography (OPT) is a computed tomography technique at optical frequencies for samples of 0.5-15 mm in size, which fills an important "imaging gap" between confocal microscopy (for smaller samples) and large-sample methods such as fluorescence molecular tomography or micro magnetic resonance imaging. OPT operates in either fluorescence or transmission mode. Two-dimensional (2D) projections are taken over 360° with a fixed rotational increment around the vertical axis. Standard 3D reconstruction from 2D OPT uses the filtered backprojection (FBP) algorithm based on the Radon transform. FBP approximates the inverse Radon transform using a ramp filter that spreads reconstructed pixels to neighbor pixels thus producing streak and other types of artifacts, as well as noise. Artifacts increase the variation of grayscale values in the reconstructed images. We present an algorithm that improves the quality of reconstruction even for a low number of projections by simultaneously minimizing the sum of absolute brightness changes in the reconstructed volume (the total variation) and the error between measured and reconstructed data. We demonstrate the efficiency of the method on real biological data acquired on a dedicated OPT device.
- Klíčová slova
- artifacts, data mismatch, microscopy, optical projection tomography, total variation,
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND OBJECTIVES: Optical coherence tomography angiography (OCTA) is a noninvasive high-resolution imaging technique for assessing the retinal vasculature and is increasingly used in various ophthalmologic, neuro-ophthalmologic, and neurologic diseases. To date, there are no validated consensus criteria for quality control (QC) of OCTA. Our study aimed to develop criteria for OCTA quality assessment. METHODS: To establish criteria through (1) extensive literature review on OCTA artifacts and image quality to generate standardized and easy-to-apply OCTA QC criteria, (2) application of OCTA QC criteria to evaluate interrater agreement, (3) identification of reasons for interrater disagreement, revision of OCTA QC criteria, development of OCTA QC scoring guide and training set, and (4) validation of QC criteria in an international, interdisciplinary multicenter study. RESULTS: We identified 7 major aspects that affect OCTA quality: (O) obvious problems, (S) signal strength, (C) centration, (A) algorithm failure, (R) retinal pathology, (M) motion artifacts, and (P) projection artifacts. Seven independent raters applied the OSCAR-MP criteria to a set of 40 OCTA scans from people with MS, Sjogren syndrome, and uveitis and healthy individuals. The interrater kappa was substantial (κ 0.67). Projection artifacts were the main reason for interrater disagreement. Because artifacts can affect only parts of OCTA images, we agreed that prior definition of a specific region of interest (ROI) is crucial for subsequent OCTA quality assessment. To enhance artifact recognition and interrater agreement on reduced image quality, we designed a scoring guide and OCTA training set. Using these educational tools, 23 raters from 14 different centers reached an almost perfect agreement (κ 0.92) for the rejection of poor-quality OCTA images using the OSCAR-MP criteria. DISCUSSION: We propose a 3-step approach for standardized quality control: (1) To define a specific ROI, (2) to assess the occurrence of OCTA artifacts according to the OSCAR-MP criteria, and (3) to evaluate OCTA quality based on the occurrence of different artifacts within the ROI. OSCAR-MP OCTA QC criteria achieved high interrater agreement in an international multicenter study and is a promising QC protocol for application in the context of future clinical trials and studies.
- MeSH
- fluoresceinová angiografie metody MeSH
- konsensus MeSH
- lidé MeSH
- optická koherentní tomografie * MeSH
- retina diagnostické zobrazování MeSH
- retinální cévy * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND: The objective of our study was to assess whether optical coherence tomography (OCT) guidance could guide intervention to avoid balloon angioplasty and stenting during primary percutaneous coronary intervention. METHODS: One hundred patients with ST-segment elevation myocardial infarction and thrombus-containing lesion were enrolled in this study. Thrombus aspiration was performed in all cases followed by an OCT study. After thrombectomy, no stent was implanted in residual significant stenosis (> 50%) if examination using OCT suggested that the occlusion was mostly thrombotic, provided that the patient was symptom-free and the Thrombolysis in Myocardial Infarction (TIMI) flow was ≥ 2. All patients managed only using thrombectomy underwent 1-week and 9-month angiography and OCT. Patients with significant lesion or those in whom thrombectomy failed to re-establish flow underwent standard treatment. RESULTS: Based on the OCT information, 20 patients (20%) were treated only with aspiration even in the presence of angiographically detected "high-grade stenosis." Angiogram and OCT performed at 1 week and 9 months showed a "normal vessel" without significant stenosis in all 20 cases. There were no cases of major adverse cardiovascular event (including death, myocardial infarction, and target lesion revascularization) during the in-hospital period or at the 12-month follow-up. CONCLUSIONS: The results of our pilot study suggest that ST segment elevation myocardial infarction patients with TIMI 2/3 flow in the angiogram and without significant coronary narrowing using OCT examination (even in the presence of angiographically detected "high-grade stenosis"), in whom thrombus aspiration is performed in addition to optimal medical therapy might benefit only from thrombus aspiration without plain old balloon angioplasty/stenting during primary percutaneous coronary intervention. Validation of these preliminary data in larger randomized studies is warranted.
- MeSH
- aterosklerotický plát diagnostické zobrazování MeSH
- balónková koronární angioplastika statistika a číselné údaje MeSH
- dospělí MeSH
- infarkt myokardu terapie MeSH
- koronární angiografie MeSH
- koronární okluze diagnostické zobrazování terapie MeSH
- koronární stenóza diagnostické zobrazování terapie MeSH
- koronární trombóza klasifikace diagnostické zobrazování terapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- optická koherentní tomografie * MeSH
- pilotní projekty MeSH
- prospektivní studie MeSH
- rychlost toku krve MeSH
- stenty statistika a číselné údaje MeSH
- trombektomie * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIMS: To present a new method of dynamic Purkinje-metry and to verify it by comparison with a commercially available anterior segment optical coherence tomography CASIA2. PATIENTS AND METHODS: A dynamic Purkinje-meter with a movable fixation target was assembled. A coaxial circular pattern formed by infrared LEDs was projected onto the eye and evoked Purkinje images (1st, 3rd, 4th = P1, P3, P4). The measurement was performed on 29 eyes with an implanted toric IOL (intraocular lens), under mydriatic conditions, with reference to the visual axis. The IOL tilt was calculated from the position of a fixation target at the moment of P3 and P4 superposition. The IOL decentration was determined based on the relative position of P1 during on-axis fixation and of P3 and P4 superposition during off-axis fixation. A custom-developed software was used for distance measurements. Using CASIA2, the IOL position was fully calculated by the device. RESULTS: The mean absolute difference between CASIA2 and Purkinje-meter values was 0.6° ± 0.4° for the tilt magnitude and 10° ± 10° for the tilt direction, and 0.11 mm ± 0.08 mm for the decentration magnitude and 16° ± 14° for the decentration direction. There was no statistically significant difference between the values determined by the two methods for the tilt and decentration direction. The differences were statistically significant for the tilt and decentration magnitude. CONCLUSION: The values of IOL tilt and decentration direction are similar for both devices. The values of IOL tilt and decentration magnitude measured by Purkinje-meter are higher than those from CASIA2, but overall, they correspond to the values presented in other published studies.
- Klíčová slova
- CASIA2, Purkinje images, anterior segment optical coherence tomography, intraocular lens decentration, intraocular lens position, intraocular lens tilt,
- Publikační typ
- časopisecké články MeSH
PURPOSE: Assessment of retinal oxygen saturation, thickness of a retinal nerve fibre layer (RNFL) and functional changes in the optic nerve during optic neuritis (ON) in patients with multiple sclerosis (MS). METHODS: Thirty-two patients with ON due to MS within 3 months of onset of symptoms were enrolled [22 females, 10 males, age 34 ± 9 years, median 32.5 years, 22 patients with the clinically isolated syndrome (CIS), 10 patients with relapsing-remitting from of MS (RRMS)]. All patients were examined using optical coherence tomography (OCT model 4000, Carl Zeiss Meditec, Dublin, CA, USA), automatic optical oximetry (Oxymap ehf, Reykjavik, Iceland) and using visual evoked potentials (VEP) (Metronic Keypoint® , Minneapolis, MN, USA). RESULTS: Arterio-venous difference (AVD) was increased in patients ON affected eye compared to patients' unaffected eye (PUE) [34.2 ± 4.7 versus 31.3 ± 4.6, p = 0.044 (mean ± standard deviation)]. No statistically significant difference was found in vessel oxygen saturation as well as in RNFL thickness in ON affected eyes when compared to unaffected MS eyes and healthy individuals. Significantly lower optic nerve conduction velocity was found in the affected eye when compared to unaffected MS eye and healthy (p < 0.0001 for both comparisons). No correlation between oxygen saturation values and VEP was observed in patients with MS. CONCLUSION: The AVD in oxygen saturation is altered in patients with acute ON. In the early stage of ON, AVD could reflect inflammatory and metabolic changes in the affected eye. Therefore, oximetry could be used as another diagnostic method in MS patients in suspicion of ON. This result would be promising for future investigation in this field.
- Klíčová slova
- multiple sclerosis, optic neuritis, optical coherence tomography, oximetry,
- MeSH
- discus nervi optici patologie MeSH
- dospělí MeSH
- kyslík metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- nervová vlákna patologie MeSH
- optická koherentní tomografie MeSH
- oxymetrie MeSH
- pilotní projekty MeSH
- retinální gangliové buňky patologie MeSH
- spotřeba kyslíku fyziologie MeSH
- zánět zrakového nervu metabolismus patologie MeSH
- zrakové evokované potenciály fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- kyslík MeSH
Primary percutaneous coronary intervention (PCI) is an effective treatment for myocardial infarction with ST-segment elevation. However, the stent may slow (slow-flow) or even interrupt the flow (no-reflow) in the infarct-related artery with an increase in short-term and long-term mortality. Due to these limitations there is an effort to search for alternative methods or certain modifications of existing PCI. Present article introduces a modified PCI and results of trombo-aspiration technique by optical coherence tomography (OCT). The article presents the results of our clinical study and brief case report. Our pilot project involved 100 patients with STEMI in 2011-2012. 20 patients (20%) were initially treated only with trombo-aspiration without stent implantation, based on OCT. Control angiography and OCT done 9 months after event have revealed insignificant stenosis in all patients. It is plausible that universal medical procedure with stenting is not suitable for all patients with STEMI and especially patients with large thrombus may benefit from the alternative procedure performed by manually trombo-aspiration technique with intensive anticoagulant/antiaggregant therapy. Nevertheless, only randomized trials with sufficiently follow-up may confirm this hypothesis.
- MeSH
- Brugadův syndrom MeSH
- infarkt myokardu komplikace diagnostické zobrazování terapie MeSH
- koronární angioplastika metody MeSH
- koronární trombóza komplikace terapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci převodního systému srdečního MeSH
- optická koherentní tomografie MeSH
- pilotní projekty MeSH
- převodní systém srdeční abnormality MeSH
- rentgendiagnostika MeSH
- senioři MeSH
- srdeční arytmie komplikace terapie MeSH
- stenty MeSH
- trombektomie metody MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Perioperative visual loss is one of the rare but devastating complications of anesthesia and surgery. The incidence of less severe or even subclinical postoperative visual dysfunction is unknown. Therefore, we decided to perform a pilot prospective observational clinical study to evaluate whether structural changes of the retina can be detected in patients undergoing elective orthopaedic surgery by optical coherence tomography (OCT). METHODS: Adult patients indicated for elective knee replacement surgery with the absence of known retinal or optic nerve disease were included. Each patient underwent baseline OCT examination of the eyes one day before surgery and it was repeated 4-7 days after the surgery. The surgery was done under general and epidural anesthesia. RESULTS: A total of 18 patients (6 men and 12 women) at the age of 70.8±7.1 years were enrolled. We found statistically significant changes in the Macular central thickness and in a few areas of the Retinal Nerve Fiber Layer between the baseline and postoperative measurements. CONCLUSIONS: Even though we found significant changes in some parameters, we did not confirm that general anesthesia and/or surgical damage causes significant damage of the retina using OCT measurement. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04311801).
- Klíčová slova
- anesthesia, optical coherence tomography, orthopedic surgery,
- MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci retiny * MeSH
- optická koherentní tomografie metody MeSH
- ortopedické výkony * škodlivé účinky MeSH
- pilotní projekty MeSH
- poruchy zraku MeSH
- retina MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- pozorovací studie MeSH
PURPOSE: To present a case report with "unclear" and sudden decrease of left eye visual acuity and bilateral visual fields defects. METHODS: A case report. CASE PRESENTATION: A 66-year-old woman was referred to our Center of Neuroophthalmology and Orbitology by a neurologist for a history of sudden decrease of visual acuity of her left eye 3 years ago. From September 2009, she was examined at various and not only ophthalmology departments. One by one the optic nerve neuritis, traumatic, compressive or toxic neuropathy and also nutritive neuropathy because of vitamin B(12) deficiency were excluded. The patient underwent also a genetic examination for Lebers hereditary optic nerve neuropathy, but this diagnosis was not confirmed. On magnetic resonance imaging, an atrophy of both optic nerves was described, with no further progression found during the follow-up examination after one year. In available patients medical records we found out that on optical coherence tomography scans optic disc drusen of the both eyes are visible, but this wasnt described in the records. Also, an examination of Visual Evoked Potential was performed - this confirmed the diagnosis of optic disc drusen. However, our patient was further examined for visual lost of the left eye. At the time of presentation (January, 2014), her best-corrected visual acuity of the right eye was 0.5, and counting fingers at 50 cm distance with correct light projection in the left eye. Static perimetric examination demonstrated bilateral and concentric narrowing of visual fields. The eyes were parallel, with no limitation of their movements in any direction. The patient was without diplopia, the direct pupil reactions to the light were sluggish bilaterally, and anterior segments of both eyes were with no pathologies. Examination of the fundus revealed bilateral findings of pale optic disc with absent optic cup and indistinct "lumpy" margins. Waxy pearl-like irregularities of the papila of both eyes were visible even without pupil dilatation. Bilateral optic disc drusen were confirmed by ultrasonography, fundus autofluorescence and spectral-domain optical coherence tomography. CONCLUSION: Optic disc drusen are often asymptomatic, frequently it is an accidental finding during the biomicroscopy of fundus due to ordinary eye examination. Rarely, optic disc drusen can cause blood circulation failure on the optic disc with typical defects of the visual field. Thats why we shouldnt forget the optic disc drusen in the differential diagnosis considerations.
- MeSH
- diferenciální diagnóza MeSH
- discus nervi optici patologie patofyziologie MeSH
- drúzy zrakového nervu komplikace diagnóza patofyziologie MeSH
- fluoresceinová angiografie MeSH
- fundus oculi MeSH
- lidé MeSH
- optická koherentní tomografie MeSH
- senioři MeSH
- snížené vidění diagnóza etiologie patofyziologie MeSH
- zraková ostrost * MeSH
- zrakové evokované potenciály fyziologie MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH