RESUMO
RATIONALE AND OBJECTIVES: To investigate radiation dose reduction during whole body fluorodeoxyglucose (18F-FDG) positron emission tomographic (PET)/computed tomography (CT) by employing weight-based protocols. MATERIALS AND METHODS: One thousand and twenty-eight patients were referred for 18F-FDG PET/CT study with one of two protocols: conventional protocol I; 120 kVp, 120 mAs, 0.5 second rotation time, pitch 0.8 mm/rot across all body weights; four-tier body weight protocol II all used 140 kVp, 0.75 seconds rotation time and pitch 0.8 mm/rot: Protocol A (≤60 kg): 35 mAs, Protocol B (61-80 kg): 50 mAs, Protocol C (81-100 kg): 65 mAs, and Protocol D: (>101 kg): 100 mAs. All protocols employed tube current modulation. Quantitative and qualitative image visual grading characteristics assessed image quality. RESULTS: Patient demographics demonstrated no significant difference between each protocol except for patient weight in weight protocol IIB (p < 0.009). Mean effective dose in all protocols were significantly lower in Protocol B compared to A (p < 0.009). Contrast-to-noise ratio demonstrated no differences between each protocol (p < 0.21) except for weight protocol in protocol IIA (<60 kg, pâ¯=â¯0.035) with the visual grading characteristics demonstrating preference over protocol II compared to I. CONCLUSION: Significant reduction in radiation dose can be achieved using patient-specific body weight-based protocols during whole-body 18F-FDG PET/CT without compromising image quality when employing weight-based protocols.
Assuntos
Peso Corporal , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Exposição à Radiação/prevenção & controle , Protocolos Clínicos , Estudos de Coortes , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Razão Sinal-RuídoRESUMO
OBJECTIVE: To assess the awareness and attitudes of the general public in Lebanon regarding the interactions between physicians and pharmaceutical companies. SETTING: Primary healthcare clinics and shopping malls in the Greater Beirut Area. PARTICIPANTS: 263 participants completed the questionnaire, of whom 62% were female and 38% were male. Eligible participants were Arabic-speaking or English-speaking adults (age≥18â years) residing in Lebanon for at least 5â years. PRIMARY AND SECONDARY OUTCOME MEASURES: Awareness, attitudes and beliefs of the general public. RESULTS: 263 out of 295 invited individuals (89% completion rate) completed the questionnaire. While the majority of participants were aware of pharmaceutical company presence (or absence) in physicians' offices (range of 71-76% across questions), smaller percentages were aware of gift-related practices of physicians (range of 26-69% across questions). 40% thought that the acceptance of small gifts or meals by physicians is wrong/unethical. The percentage of participants reporting lower trust in physicians due to their participation in various pharmaceutical company-related activities ranged from 12% to 45% (the highest percentage being for large gifts). Participants who reported receiving free medication samples were significantly more likely to consider physicians' acceptance of small gifts as 'not a problem' than 'unethical' (OR=1.53; p=0.044). CONCLUSIONS: Participants in our survey were generally more aware of pharmaceutical company presence (or absence) in physicians' offices than of gift-related practices of physicians. While the level of trust was not affected for the majority of participants for various types of interactions, it was affected the most for accepting large gifts.