Computed tomography (CT) scanning is a relatively high-dose procedure which use has been rapidly increasing in many countries, although a decline has been observed recently in some developed countries. Relatively little is known about CT usage in Brazil. A recent report showed that number of CT procedures among outpatients of the Brazilian public healthcare system (SUS) tripled from 2001 to 2011 and about 13% of all CTs procedures were performed in pediatric and young adult patients. In the present study, we aimed to evaluate CT use in the private healthcare system, where the larger availability of CT scanners may result in a different CT usage pattern. We evaluated data from 15,892 CT procedures underwent by children and young adults (<20 years) between 2005 and 2015 in a private general hospital in the city of Rio de Janeiro. These procedures represented about 8% of the overall number of CT scans in the hospital over the study period. The number of CT examinations increased 10% per year, from 902 in 2005 to 2,376 in 2015. Head/neck was the most frequently examined body anatomical region for all age groups, except for patients aged 15-19 years for whom abdomen/pelvis was the most common scanned region. One third of the patients underwent more than one CT examination in the study hospital, with multiple CT exams increasing with patient age. The greater availability of other diagnostic imaging examinations in the private setting, such as magnetic resonance and ultrasound, could have contributed to the lower proportion of pediatric and young adult CT in the study hospital. The rapid increase of pediatric CT usage in the public and private healthcare setting reinforces the need for initiatives to avoid unwarranted CT exposure in Brazil.

OBJETIVO: Determinar os fatores de correção para a variação volumétrica dos radiofármacos contidos em recipientes de diferentes geometrias. Comparar a influência desses fatores na determinação da atividade de 99mTc e 123I utilizando dois tipos de calibradores: um com câmara de ionização e outro com detector Geiger-Müller (G-M). Avaliar o desempenho de calibradores de alguns serviços de medicina nuclear em medição de atividade de 99mTc e 123I. MATERIAIS E MÉTODOS: Foram utilizados oito calibradores, frascos de vidro 10R, seringas de plástico de 3 e 5 mL e soluções de 99mTc e 123I. Os fatores de correção foram determinados a partir das medições práticas da variação da leitura do calibrador com a variação do volume da solução no recipiente. O desempenho foi avaliado em relação ao critério de aceitação de ±10% de exatidão exigida pela norma brasileira. RESULTADOS: A variação da resposta do calibrador com a variação do volume do frasco foi bem maior no calibrador que utiliza G-M. Ela também foi maior para 123I do que para 99mTc. CONCLUSÃO: Os resultados confirmam que a resposta dos calibradores depende do volume contido nos recipientes. Essa dependência é mais crítica para os calibradores equipados com detector G-M e para 123I quando comparado com 99mTc.

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Computed tomography (CT) is an indispensable imaging technique, but radiation exposure from CT scans is of concern mainly due to the potential risk of developing cancer, mainly in children. Our group recently showed that CT use has greatly increased among outpatients using the Brazilian public health system (SUS) between 2001 and 2011. Further, CT examinations among patients younger than 20 years of age represented around 13.4% of all CT examinations in SUS between 2008 and 2011. In comparison, these examinations represented around 8% of the overall number of CT scans in a private hospital in Rio de Janeiro between 2005 and 2015, In this paper we extended the evaluation of pediatric and young adult CT use in Brazil to 25 private CT services in 8 Brazilian cities for the period 2008-2014. Data from SUS was updated to this period. Information about CT use in SUS was obtained from an online database. Data on the privately funded setting was retrieved from the Radiological Information Systems (RIS) of each CT service. Patients younger than 20 years of age underwent around 8.9% of the CT procedures in the private setting, while in SUS this proportion was around 12.7% in the same period. Pediatric and young adult CT greatly increased in both healthcare systems, but annual growth rates were less pronounced in the private than in the public healthcare system. One third of the patients in the private setting had more than one CT examination over the period investigated.