Modeling of subsurface pulsed radar for nondestructive testing of structures

The use of pulsed radar for investigating the integrity of structural elements is gaining popularity and becoming firmly established as a nondestructive test method in civil engineering. Difficulties can often arise in the interpretation of results obtained, particularly where internal details are relatively complex. One approach that can be used to understand and evaluate radar results is through numerical modeling of signal propagation and reflection. By comparing the results of a numerical modeling with those from field measurements, engineers can gain valuable insight into the probable features embedded beneath the surface of a structural element. This paper discusses a series of numerical techniques for modeling subsurface radar and compares the precision of the results with those taken from real field data. It is found that more complex problems require more sophisticated analysis techniques to obtain realistic results, with a consequential increase in the computational resources to carry out the modeling.

Diagnosis of common bile duct stones by intravenous cholangiography:prediction by ultrasound and liver function tests compared with endoscopic retrograde cholangiography

Routine intravenous cholangiography using the safer contrast medium, meglumine iotroxate, may be a useful investigation prior to laparoscopic cholecystectomy for the detection of suspected common bile duct stones. We compared this with endoscopic cholangiography.

Neonatal Ultrasound Results Following Very Preterm Birth Predict Adolescent Behavioral and Cognitive Outcome

This study investigated the association between different neonatal ultrasonographic classifications and adolescent cognitive, educational, and behavioral outcomes following very preterm birth. Participants included a group of 120 adolescents who were born very preterm (33 weeks of gestation), subdivided into three groups according to their neonatal cerebral ultrasound (US) classifications: (a) normal (N = 69), (b) periventricular hemorrhage (PVH, N = 37), and (c) PVH with ventricular dilatation (PVH + DIL, N = 14), and 50 controls. The cognitive functions assessed were full-scale IQ, phonological and semantic verbal fluency, and visual-motor integration. Educational outcomes included reading and spelling; behavioral outcomes were assessed with the Rutter Parents' Scale and the Premorbid Adjustment Scale (PAS). Adolescent outcome scores were compared among the four groups. A main effect for group was observed for full-scale IQ, Rutter Parents' Scale total scores, and PAS total scores, after controlling for gestational age, socioeconomic status and gender, with the PVH + DIL group showing the most impaired scores compared to the other groups. The current results demonstrate that routine neonatal ultrasound classifications are associated with later cognitive and behavioral outcome. Neonatal ultrasounds could aid in the identification of subgroups of children who are at increased risk of neurodevelopmental problems. These at risk subgroups could then be referred to appropriate early intervention services.

Preferences for a third-trimester ultrasound scan in a low-risk obstetric population: a discrete choice experiment

Objective: Establish maternal preferences for a third-trimester ultrasound scan in a healthy, low-risk pregnant population.

Design: Cross-sectional study incorporating a discrete choice experiment.

Setting: A large, urban maternity hospital in Northern Ireland.

Participants: One hundred and forty-six women in their second trimester of pregnancy.

Methods: A discrete choice experiment was designed to elicit preferences for four attributes of a third-trimester ultrasound scan: health-care professional conducting the scan, detection rate for abnormal foetal growth, provision of non-medical information, cost. Additional data collected included age, marital status, socio-economic status, obstetric history, pregnancy-specific stress levels, perceived health and whether pregnancy was planned. Analysis was undertaken using a mixed logit model with interaction effects.

Main outcome measures: Women's preferences for, and trade-offs between, the attributes of a hypothetical scan and indirect willingness-to-pay estimates.

Results: Women had significant positive preference for higher rate of detection, lower cost and provision of non-medical information, with no significant value placed on scan operator. Interaction effects revealed subgroups that valued the scan most: women experiencing their first pregnancy, women reporting higher levels of stress, an adverse obstetric history and older women.

Conclusions: Women were able to trade on aspects of care and place relative importance on clinical, non-clinical outcomes and processes of service delivery, thus highlighting the potential of using health utilities in the development of services from a clinical, economic and social perspective. Specifically, maternal preferences exhibited provide valuable information for designing a randomized trial of effectiveness and insight for clinical and policy decision makers to inform woman-centred care.

Inter-observer agreement in evaluating the anterior chamber angle by ultrasound biomicroscopy

Purpose. To determine the agreement between observers in estimating the configuration of the human anterior chamber angle (ACA) using ultrasound biomicroscopy (UBM). Methods. Two masked clinicians used UBM images to estimate, in 41 eyes, the configuration of the ACA, especially (1) the position of contact between the peripheral iris and the inside of the eye wall, (2) the angularity of the approach to the ACA, and (3) the curvature of the peripheral iris. Agreement between observers was evaluated by the kappa statistic. Results. Inter-observer agreement in assessing the iris insertion (kappa = 0.79), angular width (Kappa = 0.95), and the peripheral iris curvature (kappa = 0.84) was high. Conclusions. The agreement between observers in evaluating the anterior chamber angle configuration by UBM was excellent.

Increasing the size of a small peripheral iridotomy widens the anterior chamber angle:An ultrasound biomicroscopy study

Purpose: A peripheral iridotomy (PI) is the treatment of choice for pupillary block. In this study we investigated the effect of enlarging the size of a small PI on the anterior chamber angle in patients with angle closure using ultrasound biomicroscopy (UBM). Patients and Methods: Patients who had been treated with laser peripheral iridotomy for angle closure and were identified to have a small patent PI (<100 µm) with still appositionally closed anterior chamber angle were selected prospectively. The anterior chamber angle was assessed using UBM. The angle opening distance 500 µm from the scleral spur (AOD500) as well as the anterior and posterior chamber depth (ACD and PCD) 1000 µm from the scleral spur was measured. In addition, the ACD/PCD ratio was calculated. Afterwards, the PI was enlarged using an Nd: YAG laser and the UBM measurements were repeated as described above. Results: Six eyes of six patients were examined. After the enlargement of the PI the average AOD500 increased from 109 µm (±36) to 147 µm (±40) (p

Agreement between clinical and ultrasound biomicroscopy findings in different types of glaucoma

Purpose. To evaluate agreement between clinical examination (slit lamp examination and gonioscopy) and ultrasound biomicroscopy (UBM) in characterizing various features of the anterior chamber angle and adjacent structures. Methods. Twenty-eight patients (51 eyes) with open angle glaucoma (14), closed angle glaucoma (4), narrow angle and/or plateau iris (10), who had undergone UBM between March 94 and September 95 were studied. Evaluated parameters included angle width, iris configuration and presence of angle closure. The UBMs were reviewed in a masked fashion. Results. In 87.8% of cases there was agreement (within 10 degrees) between gonioscopic and UBM estimates of angle width. In all cases with greater than 10 degrees difference (12.2%) the angle size estimated by UBM was less than that estimated clinically. Iris configuration was graded identically in 51% of cases; the majority of disagreements (76.1%) occurred in cases graded as "regular" by gonioscopy and as "steep" by UBM. Angle closure was judged to be present more frequently by UBM. Conclusions. UBM and gonioscopy do not necessarily yield identical values for angle width, iris configuration, and presence of angle closure.

Ultrasound biomicroscopy in deep sclerectomy

Purpose: To evaluate by ultrasound biomicroscopy (UBM) the anatomical characteristics and the intraocular pressure (IOP) lowering mechanisms of deep sclerectomy after long-term follow-up. Methods: In all, 22 eyes of 21 consecutive patients who had deep sclerectomy were examined by UBM. Several UBM variables were prospectively evaluated, including the presence and maximum length and height of the intrascleral space, the minimum thickness of residual trabeculo-Descemet membrane (TDM), the presence and type of subconjunctival filtering bleb, and the presence of other possible drainage sites, for example suprachoroidal. Surgical success was considered to be achieved when the IOP was

Ultrasound biomicroscopy in infantile glaucoma

Background: Glaucoma in infants has many causes. Evaluation of the anatomy of the anterior segment of eyes with infantile glaucoma may help to determine the pathogenesis of an infant's disease and influence therapeutic decisions. Methods: Eleven eyes of six infants with glaucoma were evaluated with ultrasound biomicroscopy (UBM) to evaluate the anatomic characteristics and relationships of the anterior segment structures. Results: The anterior chamber angle, iris, lens, ciliary body, and posterior chamber angle could be imaged in detail. Elongated and anteriorly placed ciliary processes were noted in all eight eyes with trabeculodysgenesis. There were no apparent anomalies in the trabecular meshwork, or anterior chamber. In three eyes with dense corneal opacities, ultrasound biomicroscopy showed severe anterior segment disorganization and thin central corneas with posterior corneal excavation. Conclusions: Ultrasound biomicroscopy is a useful non-invasive method for evaluating infants with glaucoma in cases with corneal opacities. This information can help in surgical planning for glaucoma management.

Intraobserver and interobserver agreement in evaluating the anterior chamber angle configuration by ultrasound biomicroscopy

Purpose: To determine the intra- and interobserver agreement in assessing the configuration of the human anterior chamber angle using ultrasound biomicroscopy (UBM). Methods: Two masked clinicians used ubm images to estimate, in 41 eyes, (a) the position of contact between the peripheral iris and the inside of the eye wall, (b) the angular size of the anterior chamber angle (ACA), and (c) the curvature of the peripheral iris. Both observers, masked to the previous results, examined the same images in a second session. Agreement was evaluated using the unweighted ? statistic. Results: Intraobserver agreement in assessing the iris insertion, angular width, and the iris curvature was high (range of ? values, 0.83-0.92). Interobserver agreement in evaluating the level of iris insertion (? = 0.79), the angular width (? = 0.95), and the iris curvature (? = 0.84) was also high. Conclusion: The agreement within the same observer and between observers in evaluating the ACA configuration by UBM was excellent.

Investigations of DNA damage induction and repair resulting from cellular exposure to high dose-rate pulsed proton beams

Studies regarding the radiobiological effects of low dose radiation, microbeam irradiation services have been developed in the world and today laser acceleration of protons and heavy ions may be used in radiation therapy. The application of different facilities is essential for studying bystander effects and relating signalling phenomena in different cells or tissues. In particular the use of ion beams results advantageous in cancer radiotherapy compared to more commonly used X-rays, since the ability of ions in delivering lethal amount of doses into the target tumour avoiding or limiting damage to the contiguous healthy tissues. At the INFN-LNS in Catania, a multidisciplinary radiobiology group is strategically structured aimed to develop radiobiological research, finalised to therapeutic applications, compatible with the use of high dose laser-driven ion beams. The characteristic non-continuous dose rates with several orders of magnitude of laser-driven ion beams makes this facility very interesting in the cellular systems' response to ultra-high dose rates with non-conventional pulse time intervals cellular studies. Our group have projected to examine the effect of high dose laser-driven ion beams on two cellular types: foetal fibroblasts (normal control cells) and DU145 (prostate cancer cells), studying the modulation of some different bio-molecular parameters, in particular cell proliferation and viability, DNA damage, redox cellular status, morphological alterations of both the cytoskeleton components and some cell organelles and the possible presence of apoptotic or necrotic cell death. Our group performed preliminary experiments with high energy (60 MeV), dose rate of 10 Gy/min, doses of 1, 2, 3 Gy and LET 1 keV/µm on human foetal fibroblasts (control cells). We observed that cell viability was not influenced by the characteristics of the beam, the irradiation conditions or the analysis time. Conversely, DNA damage was present at time 0, immediately following irradiation in a dose-dependent manner. The analysis of repair capability showed that the cells irradiated with 1 and 2 Gy almost completely recovered from the damage, but not, however, 3 Gy treated cells in which DNA damage was not recovered. In addition, the results indicate the importance of the use of an appropriate control in radiobiological in vitro analysis.

Plasma IL-6 levels correlate with clinical and ultrasound measures of arthritis in patients with systemic lupus erythematosus

ObjectiveThe objective of this paper is to elucidate the role of specific cytokines in lupus (SLE) arthritis.MethodsFifty SLE and 40 RA patients had an ultrasound (US) scan of their hand as per standardized protocols. US scores were expressed per joint and as a total 'US activity' score, (sum of power Doppler (PD) and grey-scale synovial hypertrophy scores in all joints) and a total erosion score. SLE disease activity was assessed (BILAG and SELENA-SLEDAI). Plasma levels of IL-6, TNF-alpha and BLyS were measured using sandwich ELISA kits (Quantikine kits, R & D).ResultsOn the basis of the US results SLE patients were divided into three groups: erosive arthritis (n?=?20), non-erosive arthritis (n?=?18) and those with a normal US scan (n?=?12). Across the SLE groups plasma IL-6 levels correlated with CRP (p?