RESUMEN
BACKGROUND: Dual-energy CT is able to distinguish between materials based on differences in X-ray absorption at different X-ray beam energies. The strong k-edge photoelectric effect of materials with a high atomic number makes this modality ideal for identifying iodine-containing compounds. We aim to evaluate dual-energy CT for the detection of Gastrografin (GG) (diatrizoate, Bayer PLC, Reading, UK) enteric contrast medium and validate the conditions for the measurement in ex vivo samples. METHODS: Dual-energy CT acquisitions were performed to detect Gastrografin in serial dilutions of water, saline and body fluids. We also evaluated the stability of Gastrografin solutions over time at room temperature. Stool specimens were examined to validate the proposed study protocol for clinical applications. RESULTS: Concentrations as low as 0.2% of Gastrografin were reproducibly detected in vitro and ex vivo samples by DECT, with linear readings ranging from 0.2% to 25% Gastrografin. Gastrografin was shown to be stable in ex vivo biological samples, and there was no difference in detection over time. Gastrografin was detected in stool specimens when administered orally. The detection curves followed the expected saturation effect at high concentrations of iodine. CONCLUSIONS: Dual-energy CT offers a convenient, quick, reliable and reproducible method for detecting and quantifying the presence of Gastrografin in ex vivo clinical specimens. Biological solutions containing Gastrografin are stable over time. A minimum dilution level of 25% is suggested to avoid beam saturation and inaccurate results.
Asunto(s)
Medios de Contraste/química , Diatrizoato de Meglumina/química , Heces/química , Tomografía Computarizada por Rayos X/métodos , Estabilidad de Medicamentos , Humanos , Técnicas In Vitro , Fantasmas de Imagen , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: All established disease-modifying drugs for multiple sclerosis require parenteral administration, which can cause difficulties for some patients, sometimes leading to suboptimal adherence. A new electronic autoinjection device has been designed to address these issues. METHODS: Patients with relapsing multiple sclerosis currently receiving subcutaneous or intramuscular interferon beta-1a, interferon beta-1b, or glatiramer acetate completed an online questionnaire (July 4-25, 2008) that surveyed current injection practices, experiences with current injection methods, and impressions and appeal of the new device. RESULTS: In total, 422 patients completed the survey, of whom 44% used autoinjectors, 43% prefilled syringes, and 13% syringes and vials; overall, 66% currently self-injected. Physical and psychological barriers to self-injection included difficulty with injections, needle phobia, and concerns over correct injection technique. Only 40% of respondents were "very satisfied" with their current injection method. The new electronic autoinjector was rated as "very appealing" by 65% of patients. The benefits of the new device included the ability to customize injection settings and to review dosing history. CONCLUSION: New technologies may help patients overcome physical and psychological barriers to self-injection. The combination of a reliable and flexible autoinjection device with dose-monitoring technology may improve communication between health care professionals and patients, and improve treatment adherence.