Remote Non-invasive Stereoscopic Imaging of Blood Vessels: First In-vivo Results of a New Multispectral Contrast Enhancement Technology

We describe a contactless optical technique selectively enhancing superficial blood vessels below variously pigmented intact human skin by combining images in different spectral bands. Two CMOS-cameras, with apochromatic lenses and dual-band LED-arrays, simultaneously streamed Left (L) and Right (R) image data to a dual-processor PC. Both cameras captured color images within the visible range (VIS, 400–780 nm) and grey-scale images within the near infrared range (NIR, 910–920 nm) by sequentially switching between LED-array emission bands. Image-size-settings of 1280 × 1024 for VIS & 640 × 512 for NIR produced 12 cycles/s (1 cycle = 1 VIS L&R-pair + 1 NIR L&R-pair). Decreasing image-size-settings (640 × 512 for VIS and 320 × 256 for NIR) increased camera-speed to 25 cycles/s. Contrasts from below the tissue surface were algorithmically distinguished from surface shadows, reflections, etc. Thus blood vessels were selectively enhanced and back-projected into the stereoscopic VIS-color-image using either a 3D-display or conventional shutter glasses. As a first usability reconnaissance we applied this custom-built mobile stereoscopic camera for several clinical settings: • blood withdrawal; • vein inspection in dark skin; • vein detection through iodide; • varicose vein and nevi pigmentosum inspection. Our technique improves blood vessel visualization compared to the naked eye, and supports depth perception

Минералогические исследования в пещерной системе Снежная-Меженного-Иллюзия (Западный Кавказ, Бзыбский хребет): предварительные результаты и направления дальнейших работ

В статье приводятся сведения о минеральном составе водных хемогенных и водных механических отложений в пещерной системе Снежная-Меженного-Иллюзия. В состав водных хемогенных отложений входят Mg- и Sr-содержащий кальцит, арагонит, гипс, гидромагнезит, целестин, стронцианит, доломит, гетит, рутил и циркон. Водные механические отложения сложены преимущественно доломитом, кварцем и кальцитом. В схожих по морфологии и микроклимату частях пещерной системы наблюдаются одинаковые вторичные минералы.У статті наводяться відомості про мінеральний склад водних хемогенних і водних механічних відкладень в печерній системі Сніжна-Меженого-Ілюзія. До складу водних хемогенних відкладень входять кальцит, який містить Mg і Sr, арагоніт, гіпс, гідромагнезіт, целестин, стронціаніт, доломіт, гетит, рутил і циркон. Водні механічні відкладення складені переважно доломітом, кварцом і кальцитом. У схожих за морфологєю та мікрокліматом частинах печерної системи спостерігаються однакові вторинні мінерали.The article presents the preliminary characteristic of the mineral composition of chemogenic formations and clastic deposits of Snezhnaya-Mezhennogo-Illusia cave system. Chemogenic formations are composed by Mg- and Sr-calcite, aragonite, gypsum and hydromagnesite, celestite, strontianite, dolomite, goethite, rutile and zircon. Clastic sediments are composed mainly by dolomite, quartz and calcite. Same secondary minerals are observed in those parts of the cave system that have similar morphology and microclimate

High shear stress relates to intraplaque haemorrhage in asymptomatic carotid plaques

AbstractBackground and aimsCarotid artery plaques with vulnerable plaque components are related to a higher risk of cerebrovascular accidents. It is unknown which factors drive vulnerable plaque development. Shear stress, the frictional force of blood at the vessel wall, is known to influence plaque formation. We evaluated the association between shear stress and plaque components (intraplaque haemorrhage (IPH), lipid rich necrotic core (LRNC) and/or calcifications) in relatively small carotid artery plaques in asymptomatic persons.MethodsParticipants (n = 74) from the population-based Rotterdam Study, all with carotid atherosclerosis assessed on ultrasound, underwent carotid MRI. Multiple MRI sequences were used to evaluate the presence of IPH, LRNC and/or calcifications in plaques in the carotid arteries. Images were automatically segmented for lumen and outer wall to obtain a 3D reconstruction of the carotid bifurcation. These reconstructions were used to calculate minimum, mean and maximum shear stresses by applying computational fluid dynamics with subject-specific inflow conditions. Associations between shear stress measures and plaque composition were studied using generalized estimating equations analysis, adjusting for age, sex and carotid wall thickness.ResultsThe study group consisted of 93 atherosclerotic carotid arteries of 74 participants. In plaques with higher maximum shear stresses, IPH was more often present (OR per unit increase in maximum shear stress (log transformed) = 12.14; p = 0.001). Higher maximum shear stress was also significantly associated with the presence of calcifications (OR = 4.28; p = 0.015).ConclusionsHigher maximum shear stress is associated with intraplaque haemorrhage and calcifications

The Potential of MET Immunoreactivity for Prediction of Lymph Node Metastasis in Early Oral Tongue Squamous Cell Carcinoma

Objective MET positivity is independently associated with survival in oral squamous cell carcinoma (OSCC). Since MET is a known orchestrator of invasive tumor growth, we investigated its association with LNM in early oral tongue squamous cell carcinoma (OTSCC). As it is recommended by the NCCN to use tumor depth of invasion (DOI) in making decisions on elective neck dissection (END), the results obtained for MET positivity were aligned with those for DOI > 4 mm. The cutoff value used in our institution. Methods Tumor samples from patients who underwent primary tumor resection and neck dissection between 1995 and 2013, were collected from the archives of the Leiden and Erasmus University Medical Center. Immunohistochemistry with D1C2 was performed to identify MET negative (= 10% uniform positivity) cancers. ROC curve analysis and the Chi-squared test were used to investigate the association of MET positivity with LNM (pN+ and occult). Binary logistic regression was used to investigate the association of MET positivity with LNM. Results Forty-five (44.1%) of the 102 cancers were MET positive. Ninety were cN0 of which 20 were pN+ (occult metastasis). The remaining 12 cancers were cN+, of which 10 were proven pN+ and 2 were pN0. MET positivity was associated with LNM with a positive predictive value (PPV) of 44.4% and a negative predictive value (NPV) of 82.5% for pN+. For the occult group, the PPV was 36.8% and the NPV was 88.5%. Regression analysis showed that MET positivity is associated with pN+ and occult LNM (p-value < 0.05). Conclusion MET positivity is significantly associated with LNM in early OTSCC, outperforming DOI. The added value of MET positivity could be in the preoperative setting when END is being considered during the initial surgery. For cases with DO

Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro

This study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods have greatly enhanced the diagnostic capabilities for the detection of high-risk atherosclerotic plaques. IVUS RF data analysis and OCT are two techniques focusing on plaque morphology and composition. Regions of interest were selected and imaged with OCT and IVUS in 50 sections, from 14 human coronary arteries, sectioned post-mortem from 14 hearts of patients dying of non-cardiovascular causes. Plaques were classified based on IVUS RF data analysis (VH-IVUSTM), OCT and the combination of those. Histology was the benchmark. Imaging with both modalities and coregistered histology was successful in 36 sections. OCT correctly classified 24; VH-IVUS 25, and VH-IVUS/OCT combined, 27 out of 36 cross-sections. Systematic misclassifications in OCT were intimal thickening classified as fibroatheroma in 8 cross-sections. Misclassifications in VH-IVUS were mainly fibroatheroma as intimal thickening in 5 cross-sections. Typical image artifacts were found to affect the interpretation of OCT data, misclassifying intimal thickening as fibroatheroma or thin-cap fibroatheroma. Adding VH-IVUS to OCT reduced the error rate in this study

Validity of free testosterone calculation in pregnant women

Objective: Increased maternal testosterone concentration during pregnancy may affect the fetus. Therefore it is clinically relevant to have a quick and reliable method to determine free testosterone levels. Current calculators for free testosterone are suspected to perform poorly during pregnancy due to suggested competition between high levels of estradiol and free (bio-active) testosterone for sex hormone-binding globulin (SHBG) binding. Therefore, it is claimed that reliable calculation of free testosterone concentration is not possible. However, recent evidence on SHBG-binding sites questions the estradiol effect on the testosterone-SHBG binding during pregnancy. In this study, we investigated whether the free testosterone concentration can be calculated in pregnant women. Design and methods: Free testosterone was measured with a specially developed equilibrium dialysis method combined with liquid chromatography tandem mass spectrometry (LC-MS/MS). Free testosterone was also calculated with the formulas of Vermeulen et al. and Ross et al. Results: Total and free testosterone measured in healthy men and women were in good agreement with earlier reports. In pregnant women, total t estosterone values were higher than in non-pregnant women, whereas free testosterone values were comparable. Calculated free testosterone levels in pregnant women were highly correlated, but marginally higher, compared to measured free testosterone levels. Conclusions: We developed an equilibrium dialysis–LC-MS/MS method for the measurement of free testosterone in the low range of pregnant and non-pregnant women. Although during pregnancy total testosterone is increased, this is not the case for free testosterone. The free testosterone formulas perform well in pregnant women

High Frame Rate Volumetric Imaging of Microbubbles Using a Sparse Array and Spatial Coherence Beamforming

Volumetric ultrasound imaging of blood flow with microbubbles enables a more complete visualization of the microvasculature. Sparse arrays are ideal candidates to perform volumetric imaging at reduced manufacturing complexity and cable count. However, due to the small number of transducer elements, sparse arrays often come with high clutter levels, especially when wide beams are transmitted to increase the frame rate. In this study, we demonstrate with a prototype sparse array probe and a diverging wave transmission strategy, that a uniform transmission field can be achieved. With the implementation of a spatial coherence beamformer, the background clutter signal can be effectively suppressed, leading to a signal to background ratio improvement of 25 dB. With this approach, we demonstrate the volumetric visualization of single microbubbles in a tissue-mimicking phantom as well as vasculature mapping in a live chicken embryo chorioallantoic membrane

Determinants of Symptomatic Intracranial Hemorrhage After Endovascular Stroke Treatment:A Retrospective Cohort Study

Background: Symptomatic intracranial hemorrhage (sICH) is a serious complication after endovascular treatment for ischemic stroke. We aimed to identify determinants of its occurrence and location. Methods: We retrospectively analyzed data from the Dutch MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) and MR CLEAN registry. We included adult patients with a large vessel occlusion in the anterior circulation who underwent endovascular treatment within 6.5 hours of stroke onset. We used univariable and multivariable logistic regression analyses to identify determinants of overall sICH occurrence, sICH within infarcted brain tissue, and sICH outside infarcted brain tissue. Results: SICH occurred in 203 (6%) of 3313 included patients and was located within infarcted brain tissue in 50 (25%), outside infarcted brain tissue in 23 (11%), and both within and outside infarcted brain tissue in 116 (57%) patients. In 14 patients (7%), data on location were missing. Prior antiplatelet use, baseline systolic blood pressure, baseline plasma glucose levels, post-endovascular treatment modified treatment in cerebral ischemia score, and duration of procedure were associated with all outcome parameters. In addition, determinants of sICH within infarcted brain tissue included history of myocardial infarction (adjusted odds ratio, 1.65 [95% CI, 1.06-2.56]) and poor collateral score (adjusted odds ratio, 1.42 [95% CI, 1.02-1.95]), whereas determinants of sICH outside infarcted brain tissue included level of occlusion on computed tomography angiography (internal carotid artery or internal carotid artery terminus compared with M1: adjusted odds ratio, 1.79 [95% CI, 1.16-2.78]). Conclusions: Several factors, some potentially modifiable, are associated with sICH occurrence. Further studies should investigate whether modification of baseline systolic blood pressure or plasma glucose level could reduce the risk of sICH. In addition, determinants differ per location of sICH, supporting the hypothesis of varying underlying mechanisms. Registration: URL: https://www.isrctn.com/; Unique identifier: ISRCTN10888758