Imaging studies for diagnosing Graves' orbitopathy and dysthyroid optic neuropathy

Although the diagnosis of Graves' orbitopathy is primarily made clinically based on laboratory tests indicative of thyroid dysfunction and autoimmunity, imaging studies, such as computed tomography, magnetic resonance imaging, ultrasound and color Doppler imaging, play an important role both in the diagnosis and follow-up after clinical or surgical treatment of the disease. Imaging studies can be used to evaluate morphological abnormalities of the orbital structures during the diagnostic workup when a differential diagnosis versus other orbital diseases is needed. Imaging may also be useful to distinguish the inflammatory early stage from the inactive stage of the disease. Finally, imaging studies can be of great help in identifying patients prone to develop dysthyroid optic neuropathy and therefore enabling the timely diagnosis and treatment of the condition, avoiding permanent visual loss. In this paper, we review the imaging modalities that aid in the diagnosis and management of Graves' orbitopathy, with special emphasis on the diagnosis of optic nerve dysfunction in this condition.

Three-dimensional Doppler evaluation of single spherical samples from the placenta: intra- and interobserver reliability

Objective To evaluate the intra- and interobserver reliability of assessment of three-dimensional power Doppler (3D-PD) indices from single spherical samples of the placenta. Methods Women with singleton pregnancies at 2440 weeks' gestation were included. Three scans were independently performed by two observers; Observer 1 performed the first and third scan, intercalated by the scan of Observer 2. The observers independently analyzed the 3D-PD datasets that they had previously acquired using four different methods, each using a spherical sample: random sample extending from basal to chorionic plate; random sample with 2 cm3 of volume; directed sample to the region subjectively determined as containing more color Doppler signals extending from basal to chorionic plate; or directed sample with 2 cm3 of volume. The vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were evaluated in each case. The observers were blinded to their own and each other's results. Additional evaluation was performed according to placental location: anterior, posterior and fundal or lateral. Intra- and interobserver reliability was assessed by intraclass correlation coefficients (ICC). Results Ninety-five pregnancies were included in the analysis. All three placental 3D-PD indices showed only weak to moderate reliability (ICC < 0.66 and ICC < 0.48, intra- and interobserver, respectively). The highest values of ICC were observed when using directed spherical samples from basal to chorionic plate. When analyzed by placental location, we found lower ICCs for lateral and fundal placentae compared to anterior and posterior ones. Conclusion Intra- and interobserver reliability of assessment of placental 3D-PD indices from single spherical samples in pregnant women greater than 24 weeks' gestation is poor to moderate, and clinical usefulness of these indices is likely to be limited. Copyright (c) 2012 ISUOG. Published by John Wiley & Sons, Ltd.

Presumed normal ultrasonographic findings of the testis and epididymis of Botos (Inia Geoffrensis)

Fifteen live adult male botos, or Amazon river dolphins (Inia geoffrensis), were examined using ultrasonography during the yearly capture expedition, between October and November 2005, at the Mamiraua Sustainable Development Reserve, within the Brazilian Amazon (3 degrees S, 65 degrees W). All examinations were performed with a Sonosite 180 plus ultrasound unit in conjunction with a 2- to 5-MHz multifrequency transducer convex array 180 Plus/Elite-C60. Age and maturity estimates were determined considering the body length, weight, and external characteristics. In all examinations, the testes were discerned by the presence of a hyperechoic central line, called the mediastinum testis, a landmark for their identification during ultrasonography. No significant differences in echogenicity were detected on the ultrasonographic appearance of the testes among the studied animals. On adult male botos, apparent parenchymal nodulation of the testis was observed on scanning in most of the animals and probably constituted evidence of reproductive maturity. Using the color Doppler technique, blood flow was detected along the mediastinum testis that progressively decreased toward the periphery of this organ. Little blood flow could be identified by color Doppler. Power Doppler allowed better accuracy to identify testicular vessels, their topography, and their differentiation from adjacent structures. Ultrasonographic examination provides useful data for morphologic characterization of the boto's testes. Examination using Doppler techniques was considered a valuable tool to evidence blood flow through the testicular parenchyma.

Sonothrombolysis for acute ischemic stroke: a systematic review of randomized controlled trials

Object. Sonothrombolysis has recently been considered an emerging modality for the treatment of stroke. The purpose of the present paper was to review randomized clinical studies concerning the effects of sonothrombolysis associated with tissue plasminogen activator (tPA) on acute ischemic stroke. Methods. Systematic searches for literature published between January 1996 and July 2011 were performed for studies regarding sonothrombolysis combined with tPA for acute ischemic stroke. Only randomized controlled trials were included. Data extraction was based on ultrasound variables, patient characteristics, and outcome variables (rate of intracranial hemorrhages and arterial recanalization). Results. Four trials were included in this study; 2 trials evaluated the effect of transcranial Doppler (TCD) ultrasonography on sonothrombolysis, and 2 addressed transcranial color-coded duplex (TCCD) ultrasonography. The frequency of ultrasound waves varied from 1.8 to 2 MHz. The duration of thrombus exposure to ultrasound energy ranged from 60 to 120 minutes. Sample sizes were small, recanalization was evaluated at different time points (60 and 120 minutes), and inclusion criteria were heterogeneous. Sonothrombolysis combined with tPA did not lead to an increase in symptomatic intracranial hemorrhagic complications. Two studies demonstrated that patients treated with ultrasound combined with tPA had statistically significant higher rates of recanalization than patients treated with tPA alone. Conclusions. Despite the heterogeneity and the limitations of the reviewed studies, there is evidence that sonothrombolysis associated with tPA is a safe procedure and results in an increased rate of recanalization in the setting of acute ischemic stroke when wave frequencies and energy intensities of diagnostic ultrasound systems are used. (http://thejns.org/doi/abs/10.3171/2011.10.FOCUS11251)

Hand-carried ultrasound performed at bedside in cardiology inpatient setting – a comparative study with comprehensive echocardiography

Abstract Background Hand-carried ultrasound (HCU) devices have been demonstrated to improve the diagnosis of cardiac diseases over physical examination, and have the potential to broaden the versatility in ultrasound application. The role of these devices in the assessment of hospitalized patients is not completely established. In this study we sought to perform a direct comparison between bedside evaluation using HCU and comprehensive echocardiography (CE), in cardiology inpatient setting. Methods We studied 44 consecutive patients (mean age 54 ± 18 years, 25 men) who underwent bedside echocardiography using HCU and CE. HCU was performed by a cardiologist with level-2 training in the performance and interpretation of echocardiography, using two-dimensional imaging, color Doppler, and simple calliper measurements. CE was performed by an experienced echocardiographer (level-3 training) and considered as the gold standard. Results There were no significant differences in cardiac chamber dimensions and left ventricular ejection fraction determined by the two techniques. The agreement between HCU and CE for the detection of segmental wall motion abnormalities was 83% (Kappa = 0.58). There was good agreement for detecting significant mitral valve regurgitation (Kappa = 0.85), aortic regurgitation (kappa = 0.89), and tricuspid regurgitation (Kappa = 0.74). A complete evaluation of patients with stenotic and prosthetic dysfunctional valves, as well as pulmonary hypertension, was not possible using HCU due to its technical limitations in determining hemodynamic parameters. Conclusion Bedside evaluation using HCU is helpful for assessing cardiac chamber dimensions, left ventricular global and segmental function, and significant valvular regurgitation. However, it has limitations regarding hemodynamic assessment, an important issue in the cardiology inpatient setting.

Brazilian guidelines for the application of transcranial ultrasound as a diagnostic test for the confirmation of brain death

Neurosonological studies, specifically transcranial Doppler (TCD) and transcranial color-coded duplex (TCCD), have high level of specificity and sensitivity and they are used as complementary tests for the diagnosis of brain death (BD). A group of experts, from the Neurosonology Department of the Brazilian Academy of Neurology, created a task force to determine the criteria for the following aspects of diagnosing BD in Brazil: the reliability of TCD methodology; the reliability of TCCD methodology; neurosonology training and skills; the diagnosis of encephalic circulatory arrest; and exam documentation for BD. The results of this meeting are presented in the current paper.

The contrast-enhanced Doppler ultrasound with perfluorocarbon exposed sonicated albumin does not improve the diagnosis of renal artery stenosis compared with angiography

There are no studies investigating the effect of the contrast infusion on the sensitivity and specificity of the main Doppler criteria of renal artery stenosis (RAS). Our aim was to evaluate the accuracy of these Doppler criteria prior to and following the intravenous administration of perfluorocarbon exposed sonicated albumin (PESDA) in patients suspected of having RAS. Thirty consecutive hypertensive patients (13 males, mean age of 57 ± 10 years) suspected of having RAS by clinical clues, were submitted to ultrasonography (US) of renal arteries before and after enhancement using continuous infusion of PESDA. All patients underwent angiography, and haemodynamically significant RAS was considered when ≥50%. At angiography, it was detected RAS ≥50% in 18 patients, 5 with bilateral stenosis. After contrast, the examination time was slightly reduced by approximately 20%. In non-enhanced US the sensitivity was better when based on resistance index (82.9%) while the specificity was better when based on renal aortic ratio (89.2%). The predictive positive value was stable for all indexes (74.0%–88.0%) while negative predictive value was low (44%–51%). The specificity and positive predictive value based on renal aortic ratio increased after PESDA injection respectively, from 89 to 97.3% and from 88 to 95%. In hypertensives suspected to have RAS the sensitivity and specificity of Duplex US is dependent of the criterion evaluated. Enhancement with continuous infusion of PESDA improves only the specificity based on renal aortic ratio but do not modify the sensitivity of any index.

Doppler-guided hemorrhoidal artery ligation with rectal mucopexy technique: initial evaluation of 42 cases

The treatment of hemorrhoidal disease (HD) by conventional hemorrhoidectomy is associated with significant morbidity, mainly represented by the postoperative pain and the late return to daily activities. Doppler-guided hemorrhoid artery ligation (DGHAL) is a minimal-invasive surgical treatment for HD that has been used as an alternative method in order to reduce these inconveniences. OBJECTIVE: To analyze the initial results of the DGHAL technique associated with rectal mucopexy in the treatment of HD. METHODS:Forty-two patients with stage I, III and IV hemorrhoids who were submitted to DGHAL were analyzed from December 2010 to August 2011. Eleven patients (26%) were stage II; 21 (50%), stage III; and 10 (24%), stage IV HD. All patients were operated by the same surgeon under spinal anesthesia and using the same equipment and technique to perform the procedure. The 42 patients underwent ligation of six arterial branches followed by rectal mucopexia by uninterrupted suture. Nine patients needed concomitant removal of perianal skin tag. In the postoperative, the following parameters were evaluated: pain, tenesmus, bleeding, itching, prolapse, mucus discharge and recurrence. The mean postoperative follow-up lasted four months (one to nine months). RESULTS: Tenesmus was the most common postoperative complaint for 85.7% of patients followed by pain, in 28.6%, perianal burning, in 12.3%, mucus discharge and perianal hematoma in 4.7%. Two patients had severe postoperative bleeding and required surgical haemostasis, one of which needed blood transfusion. Ninety-five percent of the patients declared to be satisfied with the method. CONCLUSION: Even though DGHAL has complications similar to those of other surgical methods, its results present less postoperative pain, allowing faster recovery and return to work. Studies with more cases and a longer follow-up are still necessary to assess the late recurrence.

Color vision impairment in type 2 diabetes assessed by the D-15d test and the Cambridge Colour Test

Color vision impairment emerges at early stages of diabetes mellitus type 2 (DM2) and may precede diabetic retinopathy or the appearance of vascular alterations in the retina. The aim of the present study was to compare the evaluation of the color vision with two different tests - the Lanthony desaturated D-15d test (a traditional color arrangement test), and the Cambridge Colour Test (CCT) (a computerized color discrimination test) - in patients diagnosed with DM2 without clinical signs of diabetic retinopathy (DR), and in sex- and age-matched control groups. Both color tests revealed statistically significant differences between the controls and the worst eyes of the DM2 patients. In addition, the degree of color vision impairment diagnosed by both tests correlated with the disease duration. The D-15d outcomes indicated solely tritan losses. In comparison, CCT outcomes revealed diffuse losses in color discrimination: 13.3% for best eyes and 29% for worst eyes. In addition, elevation of tritan thresholds in the DM2 patients, as detected by the Trivector subtest of the CCT, was found to correlate with the level of glycated hemoglobin. Outcomes of both tests confirm that subclinical losses of color vision are present in DM2 patients at an early stage of the disease, prior to signs of retinopathy. Considering the advantages of the CCT test compared to the D-15d test, further studies should attempt to verify and/or improve the efficiency of the CCT test.

Color-space distortions following long-term occupational exposure to mercury vapor

Color vision was examined in subjects with long-term occupational exposure to mercury (Hg) vapor. The color vision impairment was assessed by employing a quantitative measure of distortion of individual and group perceptual color spaces. Hg subjects (n = 18; 42.1 +/- 6.5 years old; exposure time = 10.4 +/- 5.0 years; time away from the exposure source = 6.8 +/- 4.6 years) and controls (n = 18; 46.1 +/- 8.4 years old) were examined using two arrangement tests, D-15 and D-15d, in the traditional way, and also in a triadic procedure. From each subject`s `odd-one-out` choices, matrices of inter-cap subjective dissimilarities were derived and processed by non-metric multidimensional scaling (MDS). D-15d results differed significantly between the Hg-group and the control group (p < 0.05), with the impairment predominantly along the tritan axis. 2D perceptual color spaces, individual and group, were reconstructed, with the dimensions interpreted as the red-green (RG) and the blue-yellow (BY) systems. When color configurations from the Hg-group were compared to those of the controls, they presented more fluctuations along both chromatic dimensions, indicating a statistically significant difference along the BY axis. In conclusion, the present findings confirm that color vision impairments persist in subjects that have received long-term occupational exposure to Hg-vapor although, at the time of testing, they were presenting mean urinary concentration within the normal range for non-exposed individuals. Considering the advantages of the triadic procedure in clinical evaluation of acquired color vision deficiencies, further studies should attempt to verify and/or improve its efficacy.

A computer-controlled color vision test for children based on the Cambridge Colour Test

The present study aimed at providing conditions for the assessment of color discrimination in children using a modified version of the Cambridge Colour Test (CCT, Cambridge Research Systems Ltd., Rochester, UK). Since the task of indicating the gap of the Landolt C used in that test proved counterintuitive and/or difficult for young children to understand, we changed the target Stimulus to a patch of color approximately the size of the Landolt C gap (about 7 degrees Of Visual angle at 50 cm from the monitor). The modifications were performed for the CCT Trivector test which measures color discrimination for the protan, deutan and tritan confusion lines. Experiment I Sought to evaluate the correspondence between the CCT and the child-friendly adaptation with adult subjects (n = 29) with normal color vision. Results showed good agreement between the two test versions. Experiment 2 tested the child-friendly software with children 2 to 7 years old (n = 25) using operant training techniques for establishing and maintaining the subjects` performance. Color discrimination thresholds were progressively lower as age increased within the age range tested (2 to 30 years old), and the data-including those obtained for children-fell within the range of thresholds previously obtained for adults with the CCT. The protan and deutan thresholds were consistently lower than tritan thresholds, a pattern repeatedly observed in adults tested with the CCT. The results demonstrate that the test is fit for assessment of color discrimination in young children and may be a useful tool for the establishment of color vision thresholds during development.

Irreversible color vision losses in patients with chronic mercury vapor intoxication

This longitudinal study addresses the reversibility of color vision losses in subjects who had been occupationally exposed to mercury vapor. Color discrimination was assessed in 20 Hg-exposed patients (mean age = 42.4 +/- 6.5 years; 6 females and 14 males) with exposure to Hg vapor during 10.5 +/- 5.3 years and away from the work place (relative to 2002) for 6.8 +/- 4.2 years. During the Hg exposure or up to one year after ceasing it, mean urinary Hg concentration was 47 +/- 35.4 mu g/g creatinine. There was no information on Hg urinary concentration at the time of the first tests, in 2002 (Ventura et al., 2005), but at the time of the follow-up tests, in 2005, this value was 1.4 +/- 1.4 mu g/g creatinine for patients compared with 0.5 +/- 0.5 mu g/g creatinine for controls (different group from the one in Ventura et al. (2005)). Color vision was monocularly assessed using the Cambridge Colour Test (CCT). Hg-exposed patients had significantly worse color discrimination (p < 0.02) than controls, as evaluated by the size of MacAdam`s color discrimination ellipses and color discrimination thresholds along protan, deutan, and tritan confusion axes. There were no significant differences between the results of the study in Ventura et al. (2005) and in the present follow-up measurements, in 2005, except for worsening of the tritan thresholds in the best eye in 2005. Both chromatic systems, blue-yellow and red-green, were affected in the first evaluation (Ventura et al., 2005) and remained impaired in the follow-up testing, in 2005. These findings indicate that following a long-term occupational exposure to Hg vapor, even several years away from the source of intoxication, color vision impairment remains irreversible.

Characterization of Opsin Gene Alleles Affecting Color Vision in a Wild Population of Titi Monkeys (Callicebus brunneus)

The color vision of most platyrrhine primates is determined by alleles at the polymorphic X-linked locus coding for the opsin responsible for the middle- to long-wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunneus (the brown titi monkey), a primate that an earlier study suggests may possess an unusual number of alleles at this locus and thus may be a subject of special interest in the study of primate color vision. Direct sequencing of regions of the M/L opsin gene using feces-, blood-, and saliva-derived DNA obtained from 14 individuals yielded evidence for the presence of three functionally distinct alleles, corresponding to the most common M/L photopigment variants inferred from a physiological study of cone spectral sensitivity in captive Callicebus. Am. J. Primatol. 73:189-196, 2011. (C) 2010 Wiley-Liss, Inc.

Color texture analysis based on fractal descriptors

Color texture classification is an important step in image segmentation and recognition. The color information is especially important in textures of natural scenes, such as leaves surfaces, terrains models, etc. In this paper, we propose a novel approach based on the fractal dimension for color texture analysis. The proposed approach investigates the complexity in R, G and B color channels to characterize a texture sample. We also propose to study all channels in combination, taking into consideration the correlations between them. Both these approaches use the volumetric version of the Bouligand-Minkowski Fractal Dimension method. The results show a advantage of the proposed method over other color texture analysis methods. (C) 2011 Elsevier Ltd. All rights reserved.

Color tunability of intense upconversion emission from Er3+-Yb3+ co-doped SiO2-Ta2O5 glass ceramic planar waveguides

This work reports on the infrared-to-visible CW frequency upconversion from planar waveguides based on Er3+-Yb3+-doped 100-xSiO(2)-xTa(2)O(5) obtained by a sol-gel process and deposited onto a SiO2-Si substrate by dip-coating. Surface morphology and optical parameters of the planar waveguides were analyzed by atomic force microscopy and the m-line technique. The influence of the composition on the electronic properties of the glass-ceramic films was followed by the band gap ranging from 4.35 to 4.51 eV upon modification of the Ta2O5 content. Intense green and red emissions were detected from the upconversion process for all the samples after excitation at 980 nm. The relative intensities of the emission bands around 550 nm and 665 nm, assigned to the H-2(11/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2), and F-4(9/2) -> I-4(15/2) transitions, depended on the tantalum oxide content and the power of the laser source at 980 nm. The upconversion dynamics were investigated as a function of the Ta2O5 content and the number of photons involved in each emission process. Based on the upconversion emission spectra and 1931CIE chromaticity diagram, it is shown that color can be tailored by composition and pump power. The glass ceramic films are attractive materials for application in upconversion lasers and near infrared-to-visible upconverters in solar cells.