Measuring the Radiopacity of Luting Cements, dowels, and Core Build-up Materials with a Digital Radiography System Using a CCD Sensor

PURPOSE: This study assessed the radiopacity of five luting cements, five dowels, and five core build-up materials using two target distances. MATERIALS AND METHODS: Materials were analyzed using a modified version of ISO protocol 4049. samples 1 mm thick were digitally radiographed alongside a stepwedge of aluminum alloy 1100 using a Trophy RVG-4 CCD sensor and 70 kVp X-ray generator. The gray-scale values of the stepwedge and sample were converted to X-ray absorbencies. The relationship between X-ray absorbance and aluminum thickness was linear for thicknesses less than 10 mm and followed a power-law relationship above 10 mm. These relations were used to convert the absorbencies of the samples into aluminum thicknesses. The radiopacity data was subjected to ANOVA/Student-Newman-Keuls testing. RESULTS: All materials were more radiopaque than equivalent thicknesses of aluminum. Each product category contained a wide range of radiopacities. Syringe-dispensed materials tended to be less radiopaque than materials dispensed by mechanically assisted syringe or mixed by hand (p < 0.01). Target distance did not affect the measured radiopacity so long as the exposure time was suitably adjusted (p= 0.86). CONCLUSIONS: All luting cements and core materials met or exceeded the ISO minimums. The tested metal-reinforced glass ionomer core build-up materials were extremely radiopaque. Some publications suggest that excessively radiopaque core materials can hinder a clinician's ability to spot voids or marginal defects.     

Uterus duplex with a unilaterally imperforate vagina--diagnosis and treatment. Report of two cases and review of the literature

Severe cyclic dysmenorrhoea in a young woman with a unilateral abdominopelvic mass terminating in a purpuric bulge in the lateral vaginal wall, and resulting in renal agenesis ipsilateral to the pelvic mass, suggests uterus didelphys with unilaterally imperforate vagina. A report of two cases, their diagnostic and therapeutic approach and review of the literature are presented.     

Carbonate content in developing human and bovine enamel

The present study describes the detailed changes in carbonate distribution throughout the different stages of development in human and bovine enamel, from early formation to maturation. Twenty-two human maxillary and mandibular deciduous anterior teeth and 46 bovine teeth were studied. The major mineral ions, calcium and phosphorus, were also analyzed to facilitate comparison of carbonate content with progressing mineralization. The results showed that as enamel matured and mineral concentration increased, carbonate concentration decreased. The observed decrease in percent carbonate per weight enamel mineral may be due to dilution by an influx of relatively carbonate-free mineral, and could, in part, explain the observed increase in crystallinity of enamel mineral as the tissue matures.     

Sertraline does not alter steady-state concentrations or renal clearance of lithium in healthy volunteers.

An open-label, placebo-controlled study was conducted to determine the effects of sertraline on the steady-state levels and renal clearance of lithium in 20 healthy volunteers. Subjects received 600 mg of lithium twice daily for 9 days. On the evening of day 8, subjects received orally either placebo or 100 mg of sertraline; these were administered twice, 8 hours apart, beginning 2 hours after the evening dose of lithium. In a comparison of day 8 with day 9 (before administration of the morning doses of lithium), sertraline was associated with only a 0.01 mEq/L (1.4%) decrease in steady-state levels and a 0.11 L/hour (6.9%) increase in the renal clearance of lithium. Neither change was statistically significant relative to placebo. Four subjects were excluded from analysis because of protocol violations or laboratory abnormalities unrelated to sertraline. Seven subjects who received lithium plus sertraline experienced side effects, mainly tremors, possibly related to treatment, whereas none of those administered lithium plus placebo experienced side effects. No sertraline-related laboratory abnormalities were observed.     

Total acrosin activity correlates with fertility potential after fertilization in vitro

OBJECTIVE: To evaluate the possible relationship between total acrosin activity in spermatozoa and fertility potential after fertilization in vitro. DESIGN: Total acrosin activity of spermatozoa was measured in 101 in vitro fertilization (IVF) cases by an observer unaware of fertilization and cleavage results. SETTING: University Hospital is a tertiary referral center offering a government supported In Vitro Fertilization Programme. PARTICIPANTS: Participants were couples undergoing IVF. INTERVENTIONS: A miniature assay measured total acrosin activity in the semen sample used for IVF. OUTCOME MEASURES: The proportion of mature oocytes fertilized, the proportion of mature oocytes transferred, and fertilization of at least one mature oocyte were considered outcomes with fertility potential. RESULTS: Total acrosin activity correlated with both the proportion of mature oocytes fertilized and the proportion of mature oocytes that were transferred as cleaving embryos. Total acrosin activity was higher in cycles when one or more mature oocyte fertilized compared with cycles with failed fertilization of all mature oocytes. CONCLUSIONS: The likelihood ratio for subnormal results indicates that measurement of total acrosin activity is a fair test of the fertilizing capacity of sperm.     

Digital radiography of the chest by self-scanning linear diode arrays

Diode array digital radiography DADR is a method of radiographic imaging that combines the advantages of computer technology with self-scanning linear diode arrays. These digital images are superior to those obtained by film in recording and displaying information in the lightest and the darkest areas of the film, resulting in a balanced image of the entire thorax without compromising detail, and at reduced radiation dose. This is a direct result of the wide dynamic range, high contrast sensitivity, fiber optic coupling, small diode size, short exposure time, and rejection of scattered x-rays of the system coupled with digital post-processing enhancement of the image displayed at 1024 X 1024 pixels.     

Display of 3-dimensional ultrasonographic images for interventional procedures: volume-rendered versus multiplanar display.

OBJECTIVE: The goal of this project was to assess the display of 3-dimensional ultrasonographic images as used for interventional procedures, particularly the conspicuity of various targets and interventional devices, comparing volume-rendered (VR) versus multiplanar reformatted (MPR) display approaches. METHODS: A series of ultrasonographic phantoms were made from a petroleum gel with cornstarch used to vary the echo texture. Three-dimensional ultrasonographic target and device conspicuity were judged with a 5-point visual rating scale. The MPR image was considered the reference standard. Volume-rendered image conspicuity was judged for combinations of 7 different postprocessing display parameters and compared with MPR images. RESULTS: Definite visualization of the embedded objects occurred in 92% of MPR and 13% of VR test situations (P < .0001). Volume-rendered display was associated with a mean conspicuity degradation of 2.6 on a scale of 0 through 4 (P < .0001) compared with MPR methods. The proportion of satisfactory VR images was greatest in test situations with a large degree of difference of echogenicity between the background medium and the embedded object. The transparent-type postprocessing rendering modes were superior to the surface-type rendering modes (P < .0001). CONCLUSIONS: Current 3-dimensional ultrasonographic MPR imaging display in a solid organ environment provides better visualization performance of target and needle conspicuity than VR image display when there are not large differences in the signal levels of targeted structures and devices compared with surrounding tissues. The difficulty in viewing both target and device with VR imaging may restrict its ability to guide interventional procedures in some clinical situations.     

Perforation of the superior vena cava by a subclavian hemodialysis catheter: early detection by angiography.

A dual-lumen subclavian catheter was placed for temporary dialysis access in a 36-year-old woman. Clinical suspicion for a possible vena caval perforation by the catheter tip was confirmed by injection of contrast through the catheter. This technique allowed rapid diagnosis and prevented further potential complications related to catheter malposition.