OBJECTIVE: The present study evaluated the doses received by companions who had shared therapeutic rooms with patients undergoing treatment with 131-iodine (131I). The results were compared with the limits established by the Brazilian radiation protection regulatory standard. MATERIALS AND METHODS: Six pairs of persons (a patient and a companion sharing a same therapeutic room) were evaluated. Still, other 23 experiments were accomplished with a phantom replacing the companion. The therapeutic 131I activities given to the patients corresponded to 3700 MBq or 5550 MBq. Powdered lithium fluoride thermoluminescent dosimeters doped with magnesium, titanium and sodium were utilized for evaluating the doses. RESULTS: The results demonstrate that a person sharing a same therapeutic room, for two days, with a patient who had been given 3700 MBq or 5550 MBq of 131I, according to radioprotection recommendations, is exposed to a mean dose of (0.51 ± 0.02) mSv for a 99% confidence level. CONCLUSION: According to the Brazilian radiation protection standards there is no impediment for a person to accompany a nuclear medicine patient who has been given 3700 MBq or 5550 MBq of 131I during the patient stay in the therapeutic room.

Keywords: Nuclear medicine, Companion, Therapeutic room, Thermoluminescent dosimeter

OBJECTIVE: To perform a survey on routine quality control tests of dose calibrators at nuclear medicine units in the city of São Paulo, SP, Brazil. To evaluate the accuracy of measurements of seven dose calibrators activities, utilizing sources of clinically significant radionuclides at the calibration laboratory of Instituto de Pesquisas Energéticas e Nucleares. MATERIALS AND METHODS: The survey on quality control of dose calibrators has been based on questionnaires answered by the nuclear medicine units. Seven dose calibrators, Ga-67, Tc-99m and Tl-201 sources and a secondary standard instrument have been utilized in the accuracy study. RESULTS: The survey results on the quality control tests of the dose calibrators showed some inappropriateness, for example, the absence of daily reproducibility tests in all of the units. The accuracy tests for the seven dose calibrators showed results within the acceptable limit in compliance with the national regulations (±10%). CONCLUSION: According to the few nuclear medicine units participating in the survey, the dose calibrators quality control is unsatisfactory. The accuracy study of seven dose calibrators has not demonstrated any performance faults, and has established the calibration of these instruments for the utilized sources.

Keywords: Nuclear medicine, Dose calibrators, Calibration, Quality control

OBJECTIVE: To evaluate the consequences of incomplete necropsy reports of gunshot victims, in cases in which radiological methods were not used to locate the firearm projectiles. MATERIALS AND METHODS: A total of 8,185 necropsy reports of "Instituto Médico-Legal Afrânio Peixoto", Rio de Janeiro, Brazil, were reviewed. This corresponds to the total number of corpses of the period from January to December 2001, and 3,122 of these consisted of autopsies of gunshot victims. RESULTS: Out of these 3,122, 309 bodies were buried with the firearm projectiles in its interior, which may lead to legal investigations in the future. In the same period 23 exhumations were requested, 12 of them with the purpose of collecting projectiles. The expenses related to the performance of necropsy exams of gunshot victims were calculated in about U$ 344 whereas the expenses related to the exhumations for the purpose of collecting firearm projectiles were calculated in about U$ 399. These calculations were performed to show the total amount that could be saved and otherwise spent, if legal-medical investigations of gunshot victims were successfully performed at first examination. In conclusion, necropsy examinations of gunshot victims must follow specific protocols, since incomplete necropsies will require posterior exhumations, with unnecessary additional costs.

Keywords: Radiology, Forensic Medicine, Radioscopy, Necropsy, Bullets

The main objective of this study is to implement an impartial and efficient inspection method for a correct and secure use of ionizing radiation in nuclear medicine. The radiological protection model was tested in 113 nuclear medicine services (NMS) all over Brazil, following a biannual analysis schedule (1996, 1998, 2000 and 2002). In the analytical process, we adopted the methodology of assigning different importance levels to each of 82 features, based on the risk factors established by the "Comissão Nacional de Energia Nuclear" (CNEN) and on the International Atomic Energy Agency (IAEA) recommendations. A feature was considered a radioprotection fault when in nonconformity with the rules mentioned above, and was imparted a grade. The sum of those grades, classified the NMS in one of the three different ranges, as follows: operating without restriction - 100 points and below; operating with restriction - between 100 and 300 points; temporary shutdown - above 300 points. Permission for the second group to carry on operation should be attached to a defined and restricted period of time (6 to 12 months), considered enough for the NMS to solve the problems and submit to a new evaluation. The NMS's classified in the third group are supposed to go back into operation only after compliance with all the pending radioprotection requirements. Until the next regular evaluation, a multiplication factor 2n was applied to the recalcitrant NMS's, where n is the number of unwilling occurrences. The previous establishment of those items of radioprotection, with their respective grades, excluded subjective and personal values in the judgement and technical evaluation of the institutions.

Keywords: Nuclear medicine, Radiation protection, Rules, Inspection

The purpose of this work was to evaluate the action of the vitamin E as a radioprotective agent in the process of tissue reparation in rats submitted to a surgical procedure, which consisted of a wound done in the fore dorsal area. The animals were divided into five groups: group C (controls) - wound; group VE - previous treatment with vitamin E (90 UI); group IR - wound and irradiation of the borders three days after surgery; group VEIR - previous treatment with 90 UI of the vitamin E and irradiation of the borders three days after the surgery; group OIR - previous treatment with olive oil and irradiation of the borders three days after surgery. The radioprotective effect of the vitamin E was evaluated using hematoxylin-eosin stained specimens in order to identify granulation tissue, at 4, 7, 14 and 21 days after the surgical procedures. The results showed that 6 Gy of electron irradiation with a beam of 6 MeV caused retardation of the tissue repairing process and that vitamin E was effective as a radioprotective agent.

Keywords: Vitamin E, Radioprotective, Free radicals, Ionizing radiation, Tissue reparation

Clinical examination alone is not sufficient to precisely evaluate lymph node involvement in head and neck cancer. The results of computed tomography of the neck and lymphoscintigraphy were evaluated in 21 patients with carcinoma of the mouth and oropharynx staged N0. Nine patients were treated by homolateral and 12 by bilateral neck dissection. Sensitivity and specificity of computed tomography were 16% and 73% for homolateral side and 0% and 90% for contralateral side, respectively. Lymphatic drainage was observed in 76.2% of the cases. No-migration was associated with cases involving the retromolar region and tonsillar fossa, where injection of the 99mTc-Dextran 500 is more difficult. Bilateral migration occurred only in carcinomas of the floor of the mouth, with involvement of the midline. From these results it was concluded that computed tomography was less efficient than clinical examination. Nevertheless, it must be considered that conventional computed tomography was used. We are currently undertaking similar studies with helical computed tomography. Lymphoscintigraphy showed promising results, and the same method to evaluate sentinel lymph nodes in patients with carcinoma of the mouth is being used.

Keywords: Scintigraphy, Nuclear medicine, Computed tomography

Objective: The present study was aimed at assessing the quality of articles related to diagnostic accuracy of ultrasonography both in idiopathic and occupational carpal tunnel syndrome. Materials and Methods: A search was undertaken in electronic databases, selecting reports on systematic reviews, randomized clinical trials and observational studies. After four stages of analysis, from an initial screening to the evaluation by means of the assessment scale developed by the Critical Appraisal Skills Programme, the articles were classified according to levels of evidence, with their respective grades of recommendation. Results: Among 68 articles initially identified, only 4 have met all the methodological quality criteria proposed in the present study. Measurement of the cross-sectional area of the median nerve was the most important criterion for the diagnosis of carpal tunnel syndrome (cut-off point between 9 and 10 mm²: sensitivity = 82–86.3%; specificity = 48-87%). The four articles were given level of evidence “1b” and grade of recommendation “A”. Conclusion: The sonographic evaluation of patients with clinical suspicion of carpal tunnel syndrome can be cost-effectively performed as a first-line test, reducing the need for electrodiagnostic testing in these patients.

Keywords: Ultrasonography; Carpal tunnel syndrome; Sensitivity and specificity; Evidence-based medicine.

Objective: The present study was aimed at determining the acceptability of a national or regional phantoms bank to be deployed in Brazil for shared use in quality control activities by nuclear medicine centers. Materials and Methods: The authors analyzed the answers to a questionnaire applied to medical physicists and radioprotection supervisors in Brazilian nuclear medicine centers. Initially, the questionnaire was validated by professionals in the city of Aracaju, SE, which is located in the Northeast region. The present study sample was geographically distributed as follows: the Northeast region, with answers from 13 professionals of nuclear medicine centers; the North region, with 2 professionals; the South region, with 7 professionals; the Southeast region, with 43 professionals; and the Midwest region, with 2 professionals. Results: According to the data analyzed, 82% of the respondents consider that the implementation of a phantoms bank would be a suitable alternative for improving nuclear medicine quality control. The interest in sharing the bank was reported by 87% of the respondents. Conclusion: The present study demonstrated the motivation for a shared use of a future phantoms bank.

Keywords: Nuclear medicine; Quality control; Phantom.

Objetivo: A principal utilidade da tomografia por emissão de pósitrons com 18-fluordeoxiglicose (FDG-PET) está no estadiamento do câncer de pulmão. Porém, ela também pode ser utilizada para diferenciar lesões pulmonares indeterminadas, mas seu impacto na ressecção cirúrgica de lesões benignas é desconhecido. O objetivo deste estudo foi comparar a prevalência de lesões benignas em toracotomias feitas por suspeição de câncer de pulmão, antes e após a introdução do FDG-PET, em um centro de referência de cirurgia torácica. Materiais e Métodos: Os autores analisaram, prospectivamente, uma base de dados cirúrgicos de todos os pacientes consecutivos submetidos a toracotomia por câncer de pulmão suspeito ou comprovado e compararam a prevalência de lesões benignas em dois grupos ao longo de dois anos consecutivos, respectivamente antes (grupo I) e depois (grupo II) da introdução da FDG-PET. Resultados: Ressecção cirúrgica foi feita em 1.233 pacientes durante o período do estudo. A prevalência de lesões benignas na cirurgia nos grupos I e II foi similar (44/626 e 41/607, ambas correspondendo a 7%), e também no grupo II, entre aqueles submetidos a FDG-PET e os restantes (21/301 e 20/306 respectivamente, ambos correspondendo a 7%). No grupo II, dos 21 pacientes com lesões benignas submetidos a FDG-PET, 19 tiveram um estudo falso-positivo (valor médio padrão de captação 5.3 [faixa 2.6–12.7]). Desses, respectivamente 13 e 4 pacientes tiveram broncoscopia não diagnóstica e biópsia transtorácica percutânea de pulmão antes da toracotomia. Não houve diferença na proporção de lesões benignas diferentes ressecadas entre o grupo I e aqueles submetidos a FDG-PET no grupo II. Conclusão: A introdução da FDG-PET não alterou a proporção de pacientes submetidos a toracotomia por lesões benignas, principalmente devido à avidez pelo isótopo de algumas lesões não malignas. Tais resultados falsos-positivos devem ser considerados nos casos em que se contempla a possibilidade de ressecção cirúrgica em pacientes com câncer de pulmão não confirmado.

Keywords: Tomografia por emissão de pósitrons; Tomografia computadorizada; Pulmão – lesões benignas ou congênitas; Câncer de pulmão – diagnóstico e estadiamento; Câncer de pulmão – cirurgia.

OBJECTIVE: To determine correction factors for the variation in volume of radiopharmaceuticals in containers of different geometries, comparing the influence of such factors on the determination of ^99mTc and ¹²³I activity with two types of calibrators – one with ionization chamber and another with Geiger-Müller (G-M) detector –; and to evaluate calibrators performance in the measurement of ^99mTc and ¹²³I activities. MATERIALS AND METHODS: Eight calibrators, 10R glass vials, 3 and 5 mL plastic syringes and ^99mTc and ¹²³I solutions were utilized. The correction factors were determined with basis on practical measurements of the variation in the calibrators' response according to the volume of radionuclide solution in the glass vials. The performance was evaluated according to the acceptance criterion of ±10% accuracy required by the Brazilian standard. RESULTS: The variation of the calibrators' response according to the variation in radionuclide volume was reasonably greater in the calibrator with G-M detector. It was also greater for ¹²³I than for ^99mTc. CONCLUSION: The results confirm that the calibrators' response depends on the radionuclide volume contained in the vials. Such dependence is more critical for the calibrators equipped with G-M detector and for ¹²³I as compared with ^99mTc.

Keywords: Radionuclides calibrator; Nuclear medicine; Activity; Tc-99m; I-123.

The present report describes the case of a 43-year-old diabetic patient with facial pain, protruding eyes, nasal congestion and decreased right vision (involvement of the ipsilateral cranial nerves III, IV and V). Computed tomography showed diffuse sinusitis at right, cribriform plate erosion and presence of a hypodense collection in the frontal lobe with peripheral enhancement. Magnetic resonance imaging confirmed the presence of a cerebral abscess. Samples were collected from the lesion, confirming hyphae compatible with mucormycosis.

Keywords: Syndrome; Cavernous sinus; Mucormycosis.

The present report is aimed at describing a rare case of cranial malformation - cloverleaf skull syndrome -, whose presence was noticed after the birth of a child with signs of abnormality. Imaging diagnosis methods such as computed tomography and conventional radiography were used to characterize the syndrome.

Keywords: Syndrome; Malformation; Computed tomography.

OBJECTIVE: To investigate the outpatient access to nuclear medicine procedures by means of the Brazilian Unified Health System (SUS), analyzing the correspondence between data provided by this system and those from Comissão Nacional de Energia Nuclear (CNEN) (National Commission of Nuclear Energy). MATERIALS AND METHODS: Data provided by Datasus regarding number of scintillation chambers, outpatient procedures performed from 2008 to 2012, administrative responsibility for such procedures, type of service providers and outsourced services were retrieved and evaluated. Also, such data were compared with those from institutions certified by CNEN. RESULTS: The present study demonstrated that the system still lacks maturity in terms of correct data input, particularly regarding equipment available. It was possible to list the most common procedures and check the growth of the specialty along the study period. Private centers are responsible for most of the procedures covered and reimbursed by SUS. However, many healthcare facilities are not certified by CNEN. CONCLUSION: Datasus provides relevant data for analysis as done in the present study, although some issues still require attention. The present study has quantitatively depicted the Brazilian reality regarding access to nuclear medicine procedures offered by/for SUS.

Keywords: SUS; Nuclear medicine; Gamma camera.

OBJECTIVE: To study the influence that the scan percentage tool used in partial k-space acquisition has on the quality of images obtained with magnetic resonance imaging equipment. MATERIALS AND METHODS: A Philips 1.5 T magnetic resonance imaging scanner was used in order to obtain phantom images for quality control tests and images of the knee of an adult male. RESULTS: There were no significant variations in the uniformity and signal-to-noise ratios with the phantom images. However, analysis of the high-contrast spatial resolution revealed significant degradation when scan percentages of 70% and 85% were used in the acquisition of T1- and T2-weighted images, respectively. There was significant degradation when a scan percentage of 25% was used in T1- and T2-weighted in vivo images (p < 0.01 for both). CONCLUSION: The use of tools that limit the k-space is not recommended without knowledge of their effect on image quality.

Keywords: Magnetic resonance imaging; K-space; Quality control; In vivo magnetic resonance imaging.

OBJECTIVE: To evaluate the correlation of morphological criteria of the cecal appendix using computed tomography (CT) and the possible risk of developing acute appendicitis. MATERIALS AND METHODS: Cases were defined as patients with surgically confirmed acute appendicitis who had undergone CT at least twice: at diagnosis and at least one month prior. Controls were defined as emergency patients with abdominal pain who had undergone abdominal CT that excluded acute appendicitis and had also undergone CT at least one month before. RESULTS: 100 cases and 100 controls were selected for inclusion in the final analysis. Comparisons between the cases and controls revealed the following: mean transverse diameter of 0.6 cm (range, 0.4–1.0 cm) versus 0.6 cm (range, 0.6–0.8 cm; p = 0.37); mean length of 6.6 cm (range, 3.5–9.7 cm) versus 6.6 cm (range, 4.5–8.3 cm; p = 0.87); mean angle of 100º (range, 23–178º) versus 86º (range, 43–160º; p = 0.01); vertical descending orientation in 56% versus 45% (p = 0.2); absence of gas in 69% versus 77% (p = 0.34); and presence of an appendicolith in 17% versus 8% (p = 0.08). CONCLUSION: Hypothetical risk factors for obstruction of the vermiform appendix detected on CT were not associated with acute appendicitis. That suggests that factors other than those related to mechanical obstruction are implicated in the pathogenesis of acute appendicitis.

Keywords: Appendicitis; Appendix; Multidetector computed tomography; Emergency medicine.