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Biomedical subjects

William H Moore

Publications and source records attributed to William H Moore.

7 recordsLinked to original sources
PubMed2006

CT angiography with gadolinium-based contrast media.

RATIONALE AND OBJECTIVES: To evaluate the potential use of gadolinium (Gd)-based contrast media, especially that of Gadovist, a 1-molar Gd medium, in computed tomography (CT) and compare our findings with standard iodinated contrast media. MATERIAL AND METHODS: Using a live rabbit and an acrylic CT body phantom for comparative CT imaging of Gd- and I-based media. The images were acquired at 80, 100, and 120 kVp, using fixed standard beam filtration. The phantom study used serial dilutions of the Magnevist and Ultravist 300 (2.4-molar I), whereas the animal study used different volumes of Gadovist, Magnevist (0.5 molar Gd), and Ultravist administered intravenously. RESULTS: At 80 kVp for the same injection volumes of Gadovist and Ultravist, the image contrast enhancement of the aorta with Gadovist was 40% lower than that of Ultravist. In the phantom studies, however, for the same kVp settings the CT image contrast was up to fourfold higher for Gd compared with iodine when comparing the same molar concentrations of the two elements in the solutions. CONCLUSION: These results indicate a potential of Gd-based media for clinical CT angiography and provide incentive for further investigation of this subject.

Animals↗
PubMed2006

Transcutaneous RF-powered implantable minipump driven by a class-E transmitter.

We describe the design and testing of an inductive coupling system used to power an implantable minipump for applications in ambulating rats. A 2 MHz class-E oscillator driver powered a coil transmitter wound around a 33-cm-diameter rat cage. A receiver coil, a filtered rectifier, and a voltage-sensitive switch powered the implant. The implant DC current at the center of the primary coil (5.1 V) exceeded the level required to activate the solenoid valve in the pump. The variations of the implant current in the volume of the primary coil reflected the variations of the estimated coupling coefficient between the two coils. The pump could be activated in-vivo, while accommodating the vertical and horizontal movements of the animal. Advantages of this design include a weight reduction for the implant, an operation independent from a finite power source, and a remote activation/deactivation.

Animals↗
PubMed2006

Comparison of MDCT radiation dose: a phantom study.

OBJECTIVE: Recently there has been a significant increase in the use of CT imaging resulting in a significant increase in radiation exposure to the population. Few studies have compared the degree of radiation exposure among the currently available MDCT units. Our objective is to make such a comparison. MATERIALS AND METHODS: Using a Rando anthropomorphic phantom, we placed thermoluminescent dosimeters into the center, anterior, and lateral aspect of the lower chest of the phantom. Standard CT of the chest was performed with the current protocols used at our institution on 4-, 8-, and 16-MDCT GE Healthcare systems. Next, near-identical CT scans of the entire chest were performed on the same CT systems. RESULTS: The 4-detector array showed statistically significantly higher radiation dose compared with the 16-detector array with near-identical technique (p < 0.01). There is a trend toward decreasing radiation dose with the increasing number of detectors using both standard and near-identical technique. An inverse relationship exists between measured radiation dose and the number of detectors. CONCLUSION: We theorize that as the number of detectors increases, there is a decrease in the amount of nonutilized radiation exposure, thus resulting in a lower total radiation dose.

Phantoms, Imaging↗
PubMed2003

Randomized, double-blind study of the clinical efficacy of 3 days of azithromycin compared with co-amoxiclav for the treatment of acute otitis media.

BACKGROUND: Compared with 5 days of dosing, a 3 day dosing regimen of azithromycin for treatment of acute otitis media (AOM) may improve compliance, will simplify therapy for the caregiver and, by giving the same total dose as the 5 day regimen, provide more drug when the bacterial burden is highest. METHODS: Children of 6 months-12 years were enrolled if they had had symptoms and signs of AOM for <4 weeks and tympanic membrane effusion by acoustic reflectometry. Eligible children were randomized to azithromycin 10 mg/kg/day x 3 days or co-amoxiclav 45 mg/kg/day x 10 days. The primary endpoint was clinical response at day 28. RESULTS: One hundred and eighty-eight children (mean age 3.5 years) were randomized to azithromycin and 185 to co-amoxiclav. At day 10, the clinical success rate was 153/185 (83%) in children treated with azithromycin and 159/181 (88%) in children treated with co-amoxiclav. At day 28, 134/182 (74%) of the children were cured on azithromycin compared with 124/180 (69%) on co-amoxiclav. Also at day 28, signs of AOM, such as abnormal reflectometry (45% versus 59%; P = 0.017), bulging of the eardrum (10% versus 16%; P = 0.059) and loss of tympanic membrane landmarks (11% versus 22%; P = 0.010) were seen less frequently in azithromycin- than co-amoxiclav-treated children, respectively. Adverse events related to therapy were seen in 11% of azithromycin patients compared with 20% on co-amoxiclav (P = 0.014). CONCLUSIONS: Azithromycin given over 3 days is as effective as co-amoxiclav for treatment of AOM, may result in more complete resolution of tympanic membrane disease, and is better tolerated.

Acute Disease↗