1. 25-48 of 58 « 1 2 3 »
    1. Future Prospects in Dermatologic Applications of Lasers, Nanotechnology, and Other New Technologies

      Future Prospects in Dermatologic Applications of Lasers, Nanotechnology, and Other New Technologies

      We review novel technologies with diagnostic and therapeutic applications in dermatology. Among the diagnostic techniques that promise to become part of dermatologic practice in the future are optical coherence tomography, multiphoton laser scanning microscopy, Raman spectroscopy, thermography, and 7-T magnetic resonance imaging. Advances in therapy include novel light-based treatments, such as those applying lasers to new targets and in new wavelengths. Devices for home therapy are also appearing. We comment on the therapeutic uses of plasma, ultrasound, radiofrequency energy, total reflection amplification of spontaneous emission of radiation, light stimulation, and transepidermal drug delivery. Finally, we mention some basic developments in ...

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    2. Adaptive-Weighted Bilateral Filtering and Other Pre-processing Techniques for Optical Coherence Tomography

      Adaptive-Weighted Bilateral Filtering and Other Pre-processing Techniques for Optical Coherence Tomography

      This paper presents novel pre-processing image enhancement algorithms for retinal optical coherence tomography (OCT). These images contain a large amount of speckle causing them to be grainy and of very low contrast. To make these images valuable for clinical interpretation, we propose a novel method to remove speckle, while preserving useful information contained in each retinal layer. The process starts with multi-scale despeckling based on a dual-tree complex wavelet transform (DT-CWT). We further enhance the OCT image through a smoothing process that uses a novel adaptive-weighted bilateral filter (AWBF). This offers the desirable property of preserving texture within the OCT ...

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    3. Longitudinal stent elongation during retraction of entrapped jailed guidewire in a side branch with balloon catheter support: a case report

      Longitudinal stent elongation during retraction of entrapped jailed guidewire in a side branch with balloon catheter support: a case report

      A 72-year-old man underwent primary percutaneous coronary intervention for a subtotal occlusion in the mid-portion of the left anterior descending artery involving a large diagonal branch. After successful stenting with a 3.0/24 mm bare metal stent, during which, the diagonal branch was protected with a coronary guidewire, conventional retrieval of the jailed guide wire was impossible. Subsequently, several attempts at a strong retraction of the wire with the support of a balloon catheter enabled retrieval of the trapped wire. Optical coherence tomography performed after post-dilatation, revealed that the stent was elongated to the left main coronary artery, and ...

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    4. Prospectively electrocardiogram-triggered high-pitch spiral acquisition coronary computed tomography angiography for assessment of biodegradable vascular scaffold expansion: Comparison with optical coherence tomography

      Prospectively electrocardiogram-triggered high-pitch spiral acquisition coronary computed tomography angiography for assessment of biodegradable vascular scaffold expansion: Comparison with optical coherence tomography

      BVS polymeric struts are transparent to the light so that the vessel wall contour can be easily visualized using optical coherence tomography (OCT). Therefore OCT represents a unique tool for both the evaluation of the resorption process and for the assessment of acute BVS mechanical failure. Similarly, the metal-free struts allow unrestricted coronary computed tomography angiography (CCTA), thus this non invasive method might become the gold standard for a non invasive assessment of BVS. In this case we show the ability of CCTA, performed with a low X-Ray dose, to provide a good evaluation of scaffold expansion. The quantitative measurements ...

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    5. Corneal perforation by an astigmatic keratotomy performed with an optical coherence tomography–guided femtosecond laser

      Corneal perforation by an astigmatic keratotomy performed with an optical coherence tomography–guided femtosecond laser

      We present a case of corneal perforation secondary to an intrastromal astigmatic keratotomy performed with an optical coherence tomography–guided femtosecond laser. The keratotomy was concomitant with cataract surgery and resulted in a flat anterior chamber prior to the start of lens extraction. Interrupted nylon sutures were placed to seal the keratotomy prior to phacoemulsification. Escape of cavitation bubbles into the anterior chamber or the liquid interface can alert the surgeon to the possibility of unintended perforation of the endothelium or the epithelium, respectively.

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    6. Comparison by Optical Coherence Tomography of the Frequency of Lipid Coronary Plaques in Current Smokers, Former Smokers, and Non-smokers

      Comparison by Optical Coherence Tomography of the Frequency of Lipid Coronary Plaques in Current Smokers, Former Smokers, and Non-smokers

      Smoking is associated with high incidence of cardiovascular events including acute coronary syndrome (ACS). We sought to characterize coronary plaques in patients with ongoing smoking using optical coherence tomography (OCT) compared to former smokers and nonsmokers. We identified 465 coronary plaques from 182 subjects who underwent OCT imaging for all three coronary arteries. Subjects were divided into 3 groups: current smokers (n=41), former smokers (n=67) and nonsmokers (n=74). OCT analysis included the presence of lipid rich plaque, thin-cap fibroatheroma (TCFA), calcification, maximum lipid arc, lipid core length, lipid index, and fibrous cap thickness (FCT). Lipid index was ...

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    7. Frequency-Domain Optical Coherence Tomographic Analysis of Plaque Microstructures at Non-culprit Narrowings in Patients Receiving Potent Statin Therapy

      Frequency-Domain Optical Coherence Tomographic Analysis of Plaque Microstructures at Non-culprit Narrowings in Patients Receiving Potent Statin Therapy

      Potent statin therapy has been demonstrated to reduce cardiovascular events. While statins have been considered to stabilize atherosclerotic plaque, this effect has not been well characterized in vivo. We investigated the relationship between potent statin therapy and plaque microstructures imaged by frequency-domain optical coherence tomography (FD-OCT). 290 non-culprit lipid plaques in 275 patients with stable coronary artery disease receiving atorvastatin or rosuvastatin were analyzed. Patients were stratified into no statin, low- and high-dose statin group. Plaques in the high-dose statin group demonstrated a smaller lipid arc (p=0.02) and a greater fibrous cap thickness (p=0.01). In patients ...

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    8. Neoatherosclerosis as the Cause of Very Late Bare-metal Stent Restenosis: Optical Coherence Tomography Evaluation

      Neoatherosclerosis as the Cause of Very Late Bare-metal Stent Restenosis: Optical Coherence Tomography Evaluation

      To the Editor, A man aged 49 years, ex-smoker with a family history of premature ischemic heart disease, attended the emergency department after 1 month with clinical symptoms of progressive angina following even minimal exertion. In 2001, he had presented non-Q wave acute myocardial infarction and undergone conventional bare-metal stent (BMS) implantation in the mid left anterior descending artery. In 2007, a coronary angiogram for exertional angina showed no stent restenosis. Following a change in treatment, he remained asymptomatic and recorded negative exercise test results until this admission in 2012. In view of symptoms of unstable angina, a fresh coronary ...

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    9. Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2-stent techniques: Insights from optical coherence tomography

      Strategy for optimal side-branch positioning of bioresorbable vascular scaffolds in dedicated 2-stent techniques: Insights from optical coherence tomography

      We present a case of a left anterior descending artery/diagonal branch bifurcation successfully treated with a dedicated 2-stent technique utilizing bioresorbable vascular scaffolds, where the bifurcation angle did not strictly allow a T-stenting approach. We also propose a strategy to avoid or reduce scaffold overlap in the main branch, especially important in view of the bulkier size of these novel devices.

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      Mentions: St. Jude Medical
    10. Intra-Stent Tissue Evaluation within Bare Metal and Drug-Eluting Stents > 3 Years since Implantation in Patients with Mild to Moderate Neointimal Proliferation Using Optical Coherence Tomography and Virtual Histology Intravascular Ultrasound

      Intra-Stent Tissue Evaluation within Bare Metal and Drug-Eluting Stents > 3 Years since Implantation in Patients with Mild to Moderate Neointimal Proliferation Using Optical Coherence Tomography and Virtual Histology Intravascular Ultrasound

      Objective: We aimed to compare neointimal tissue characteristics between bare-metal stents (BMS) and drug-eluting stents (DES) at long-term follow-up using optical coherence tomography (OCT) and virtual histology intravascular ultrasound (VH-IVUS). Background: Neoatherosclerosis in neointima has been reported in BMS and in DES. Methods: Thirty patients with 36 stented lesions [BMS (n = 17) or DES (n = 19)] > 3 years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥ 70% diameter stenosis were excluded. Results: The median duration from implantation was 126.0 months in the BMS group and 60.0 months in the DES group ...

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    11. Optimisation of post mortem cardiac computed tomography compared to optical coherence tomography and histopathology - Technical note

      Optimisation of post mortem cardiac computed tomography compared to optical coherence tomography and histopathology - Technical note

      Introduction Coronary atherosclerosis is a leading cause of mortality. New technological developments in computed tomography (CT), including dual energy, iterative reconstructions and high definition scanning, could significantly improve the non-invasive identification of atherosclerosis plaques. Here, a new method for optimising cardiac coronary CT with optical coherence tomography (OCT) and histopathology is presented. Materials and methods Twenty human hearts obtained from autopsies were used. A contrast agent that solidifies after cooling was injected into the coronary arteries. CT scanning was performed on the heart alone as well as with the heart in a chest phantom. We used eight different CT protocols ...

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    12. Usefulness of intracoronary imaging techniques in the percutaneous treatment of in-stent restenosis

      Usefulness of intracoronary imaging techniques in the percutaneous treatment of in-stent restenosis

      We report a case of very late bare-metal stent restenosis, in which assessment by two intracoronary imaging techniques (intravascular ultrasound and optical coherence tomography) revealed the underlying mechanism (neoatherosclerosis) and facilitated percutaneous treatment (direct bare-metal stent-in-stent). We also take the opportunity to briefly describe the advantages and limitations of both techniques in this pathology.

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    13. Optical coherence tomography in the diagnosis of achromatopsia

      Optical coherence tomography in the diagnosis of achromatopsia

      CASE REPORT: The case of a fifty five year-old male with nyctalopia, photophobia, poor colour vision and nystagmus, is presented. The initial suspected diagnoses were achromatopsia and blue-cone monochromatism, since both are clinically indistinguishable. Optical coherence tomography (OCT) showed the characteristic foveal reflectivity pattern of achromatopsia. This diagnosis was subsequently confirmed by genetic study. DISCUSSION: OCT is a non-invasive diagnostic imaging method that allows tissue morphology to be observed with high resolution. Its use might be of great help to distinguish clinically similar diseases.

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    14. Ocelot catheter for the recanalization of lower extremity arterial chronic total occlusion: Mini review

      Ocelot catheter for the recanalization of lower extremity arterial chronic total occlusion: Mini review

      Peripheral arterial disease (PAD) is a growing clinical condition affecting more than 10 million patients in the United States and it is responsible for more than 120,000 amputations annually. The presence of chronic total occlusions (CTO) increases the complexity of endovascular procedures and open surgery may often be the preferred approach. Despite the optimization of the CTO devices and technique, percutaneous CTO revascularization remains a challenging procedure even for experienced operators with important complication rates. The Ocelot TM system is a novel CTO device to use real-time optical coherence tomography (OCT) imaging guidance for the recanalization of peripheral CTOs ...

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    15. Stent malapposition, as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: A case report

      Stent malapposition, as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: A case report

      A 90-year-old man was admitted to our hospital with acute ST-segment elevation myocardial infarction. He had a history of post-infarction angina pectoris 79 months ago and had a bare-metal stent (BMS) implanted in the proximal left anterior descending artery at our hospital. Emergent coronary angiography demonstrated thrombotic occlusion in the previously stented segment. After catheter thrombectomy, antegrade flow was restored, but 90% stenosis with haziness persisted in the proximal and distal portions of the previously stented segment. Intravascular ultrasound imaging showed interstrut cavities or stent malapposition at the proximal and distal sites of stented segment. In close proximity to the ...

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    16. Normal macular thickness and volume using spectral domain optical coherence tomography in a reference population

      Normal macular thickness and volume using spectral domain optical coherence tomography in a reference population

      Objective To establish normal values of macular thickness and volume obtained by the Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA, U.S.A.). Secondly, to assess the association between macular thickness and volume, sex and age. Material and methods A prospective study was conducted on patients who were seen in a hospital Retina Unit, and who only had retinal disease in one eye. All the Macular Cube 512 × 128 scan protocols were performed by the same operator. Only the healthy eye was scanned in each patient. Results A total of 100 eyes of 100 patients were analysed. The mean central ...

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    17. A Rare Mechanism of Very Late Bare Metal Stent Thrombosis—Role of Optical Coherence Imaging in Its Evaluation and Management

      A Rare Mechanism of Very Late Bare Metal Stent Thrombosis—Role of Optical Coherence Imaging in Its Evaluation and Management

      Very late stent thrombosis is an uncommon event following implantation with bare metal stents (BMS) in coronary arteries. Long term follow up studies have shown that a small number of BMS develop very late thrombosis following years of stability. Atherosclerotic transformation of neointimal tissue is increasingly being recognised as the cause of these adverse events. A 49 year-old male presented with acute inferior wall myocardial infarction resulting from thrombosis of the BMS implanted in his right coronary artery five years earlier. He was successfully thrombolysed and his coronary angiogram showed mild diffuse instent restenosis. The intravascular optical coherence tomography revealed ...

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    18. Deceived incidence of acute coronary syndrome by measurement of FFR: Diagnostic gap of vulnerable plaque between physiology and morphology

      Deceived incidence of acute coronary syndrome by measurement of FFR: Diagnostic gap of vulnerable plaque between physiology and morphology

      A 67-year-old male was admitted because of acute myocardial infarction (AMI). An emergent coronary angiography showed a total occlusion in the left anterior descending artery, and a stent was deployed. Moderate lesion stenosis was found in the right coronary artery (RCA). Fractional flow reserve indicated 0.96, and percutaneous coronary intervention was not performed. Six months later, the patient visited an emergency room due to AMI. Angiograms showed a patency of the previous stent and progressed stenosis with filling delay of the RCA. Protruding red thrombi and plaque disruption of thin-cap fibroatheroma (TCFA) were identified by optical coherence tomography. Mild ...

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    19. Very late stent thrombosis after paclitaxel-eluting stent implantation with full neointimal tissue coverage visualized by optical coherence tomography

      Very late stent thrombosis after paclitaxel-eluting stent implantation with full neointimal tissue coverage visualized by optical coherence tomography

      We present findings of a very late stent thrombosis (VLST) involving paclitaxel-eluting stents (PESs) that were fully covered by thin neointima, visualized by optical coherence tomography (OCT) in a patient receiving dual antiplatelet therapy. A 69-year-old Japanese man had been treated with 2 overlapping PESs for chronic coronary artery disease in the proximal right coronary artery. A follow-up coronary computed tomography angiography showed no restenosis in the stent site, and the result of stress myocardial perfusion imaging showed no ischemic changes. Seventeen months after the percutaneous coronary intervention, he was transported to our clinic with a diagnosis of acute myocardial ...

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    20. Long-term study of vitreomacular traction syndrome: Optical coherence tomographic patterns and surgical results

      Long-term study of vitreomacular traction syndrome: Optical coherence tomographic patterns and surgical results

      Purpose To investigate the optical coherence tomographic (OCT) patterns and long-term surgical outcomes of patients with vitreomacular traction syndrome (VMT). Methods From May 2002 to April 2008, patients with OCT-confirmed VMT who underwent vitrectomy were retrospectively reviewed. Complete pre- and postoperative ophthalmic and OCT examinations were recorded. All cases were followed for at least 2 years. The OCT patterns of VMT were classified into two groups: Group 1, V-shaped macular traction (1A: without macular detachment, 1B: with macular detachment); Group 2, U-shaped macular traction (2A: without macular detachment, 2B: with macular detachment). Multiple linear regression analysis of selective factors was ...

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    21. Optical coherence tomography of late acquired bare metal stent malapposition: Bare metal stent “diverticulosis”

      Optical coherence tomography of late acquired bare metal stent malapposition: Bare metal stent “diverticulosis”

      Figure 1. Coronary angiogram and optical coherence tomographic (OCT) images of the right coronary artery. (A) Initial lesion prior to stent placement. (B) Immediately post stent insertion. (C) At repeat angiography for NSTEMI demonstrating presence of multiple prominent “diverticuli” in the mid-segment of the stent (arrow). (D and E) OCT images demonstrating LASMA with poor neointimal coverage of affected struts and microthrombi formation within the outpouchings (arrows). (F) OCT image demonstrating good neointimal coverage of other segments of the stent. The lower OCT panel shows a longitudinal view of the pullback (proximal segments on right) with representative cross-sectional frames at ...

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    25-48 of 58 « 1 2 3 »
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