OBJECTIVE: To develop of a software tool for evaluation and control of sensitometric curves. MATERIALS AND METHODS: A method was developed for obtaining high- and low-contrast films sensitometric values, with no need to define wedge steps. RESULTS: The software named Sensito was implemented and tested utilizing data of sensitometric strips from conventional radiology, hemodynamics, and mammography departments. The feasibility of analyzing sensitometric curves from these areas remained evidenced with no need of user-dependent adjustments, and with no deviation in the evaluated sensitometric parameters and variations. CONCLUSION: The software allows the creation of a database including sensitometric curves from different processors in a same institution, easily generating gamma curves of a register and constant charts of the evaluated sensitometric characteristics, constituting an important tool for sensitometric control.

Keywords: Automatic processor, Sensitometric curve, Sensitometry

The evaluation of film processing using the STEP test (sensitometric test for the evaluation of processing) is based on the identification of significant deviations in the processor-chemicals-film system. Ideal processing conditions are established for this type of evaluation. A standard film is processed according to the manufacturer's recommendations, i.e. standard processing at 100. The film is exposed to the light of a calibrated sensitometer and the sensitometric steps are read with the use of a densitometer. A standard curve (OD × STEP) is therefore obtained. The percentual deviation should be lower than 20% compared to the standard curve. This method is useful to identify processing problems. We tested processors from several public/university hospitals and found that approximately 33% of the equipments had inadequate processing conditions.

Keywords: Automatic processors, Radiographic films, Sensitometry, STEP test

OBJECTIVE: To assess the behavior of nuchal translucency (NT) in the population of the State of Espírito Santo, Brazil, during weeks 10 to 14 of pregnancy and to establish a reference range for this population. MATERIALS AND METHODS: A transversal study was performed in 853 fetuses which presented normal cariotype or phenotype. All the fetuses were submitted to ultrasound analysis for NT measurement, during routine ultrasound examinations. The Student's "t" test and ANOVA were used in the statistical analysis. The regression test was used to adjust the better mathematical model to translate the NT behavior. RESULTS: Maternal age varied between 14 to 49 years (mean 30.2%), and 22.1% were above 35 years of age. The NT measurement increased with gestational age and the crown-rump length (CRL). In 73 normal fetuses (6.46%) the NT was thicker than 2.5 mm. The better mathematical model was the linear correlation (NT = 0.414 + 0.020 × CRL) which allowed to establish the reference range (percentiles 5, 10, 25, 50, 75, 90 and 95). CONCLUSION: The NT measurement is a manageable method during the usual ultrasonography. NT measurements increase with gestational age during weeks 10 to 14 of pregnancy. The NT measurements seen in the population of the State of Espírito Santo were similar to other population tested.

Keywords: Nuchal translucency, Reference curve, Prenatal diagnosis

Quality control of automatic processors is an important issue in the implementation of quality assurance programs in diagnostic radiology. A pilot program of quality control for automatic processors using the sensitometric method was implemented in the Radiodiagnosis Service of a University Hospital in Rio de Janeiro, RJ, Brazil. An initial survey of the darkrooms showed that they had high temperature and humidity and several light leaks; fog levels were excessively high requiring an increase in mAs of up to 24% to compensate for contrast loss; dry to dry processing time was out of control with errors of up to 56%; developer temperature was as high as 39°C (4°C higher than the recommended by the manufacturers); replenishment rates presented values as high as 417% above manufacturer's recommendations; and rejection rates of radiographic films were of the order of 21% in the mammography service. Sensitometric measurements performed before the implementation of the quality control showed values of base + fog as high as 0.24 optical density and speed and contrast outside recommended limits. The radiographic films presented several artifacts that resulted in low quality images. The pilot program consisted of the implementation of the quality control in the mammography service. Several initiatives were taken including training of the technicians, improvement of maintenance of the processors and increase in the number of patients/day from 7 to 12. This procedure allowed replenishment rates to be lowered to acceptable levels. The implementation of the quality control maintained chemical products stable keeping the sensitometric parameters under control. However, the most significant result of the program was better image quality, free from artifacts, a significant reduction in costs to the hospital and especially lower doses imparted to the patients due to the reduction in rejection rates to 7.7%.

Keywords: Quality control, Automatic processors, Sensitometric method

OBJECTIVE: To compare automatic and manual measurements of intima-media complex (IMC) in common carotid, common femoral and right subclavian arteries of HIV-infected patients in relation to a control group, taking into consideration the classical risk factors for atherosclerosis. MATERIALS AND METHODS: The study sample comprised 70 HIV-infected patients and 70 non-HIV-infected controls paired according sex and age. Automatic (gold standard) and manual measurements of IMC were performed in the carotid arteries. Manual measurements were also performed in common femoral and right subclavian arteries. Bland-Altman graphs were utilized in the comparison and the adopted level significance was 5%. RESULTS: Intima-media complex alterations were not observed in any of the individuals as the mean automatic measurement in the right common carotid (RCC) artery was considered as the gold standard. As the gold standard was compared with the manual measurements (mean, maximum and minimum), no clinically significant alteration was observed. As the gold standard was compared with other sites, the difference was statistically and clinically significant at the origin of right subclavian artery (RCC: 0.51 mm vs. 0.91 mm) (p < 0.001). CONCLUSION: HIV-infected individuals are not at higher risk for atherosclerosis than the control population.

Keywords: Atherosclerosis; Intima-media complex; Automatic; Subclavian; Femoral.

OBJECTIVE: To assess the cutoff values established by ROC curves to classify ¹⁸F-NaF uptake as normal or malignant. MATERIALS AND METHODS: PET/CT images were acquired 1 hour after administration of 185 MBq of ¹⁸F-NaF. Volumes of interest (VOIs) were drawn on three regions of the skeleton as follows: proximal right humerus diaphysis (HD), proximal right femoral diaphysis (FD) and first vertebral body (VB1), in a total of 254 patients, totalling 762 VOIs. The uptake in the VOIs was classified as normal or malignant on the basis of the radiopharmaceutical distribution pattern and of the CT images. A total of 675 volumes were classified as normal and 52 were classified as malignant. Thirty-five VOIs classified as indeterminate or nonmalignant lesions were excluded from analysis. The standardized uptake value (SUV) measured on the VOIs were plotted on an ROC curve for each one of the three regions. The area under the ROC (AUC) as well as the best cutoff SUVs to classify the VOIs were calculated. The best cutoff values were established as the ones with higher result of the sum of sensitivity and specificity. RESULTS: The AUCs were 0.933, 0.889 and 0.975 for UD, FD and VB1, respectively. The best SUV cutoffs were 9.0 (sensitivity: 73%; specificity: 99%), 8.4 (sensitivity: 79%; specificity: 94%) and 21.0 (sensitivity: 93%; specificity: 95%) for UD, FD and VB1, respectively. CONCLUSION: The best cutoff value varies according to bone region of analysis and it is not possible to establish one value for the whole body.

Keywords: ¹⁸F-NaF PET/CT; ROC curve; Cutoff values; Normal uptake; Malignant uptake

OBJECTIVE: To develop a simulator for training In fluoroscopy-guided facet joint Injections and to evaluate the learning curve for this procedure among radiology residents. MATERIALS AND METHODS: Using a human lumbar spine as a model, we manufactured five lumbar vertebrae made of methacrylate and plaster. These vertebrae were assembled in order to create an anatomical model of the lumbar spine. We used a silicon casing to simulate the paravertebral muscles. The model was placed into the trunk of a plastic mannequin. From a group of radiology residents, we recruited 12 volunteers. During simulation-based training sessions, each student carried out 16 lumbar facet injections. We used three parameters to assess the learning curves: procedure time; fluoroscopy time; and quality of the procedure, as defined by the positioning of the needle. RESULTS: During the training, the learning curves of all the students showed improvement in terms of the procedure and fluoroscopy times. The quality of the procedure parameter also showed improvement, as evidenced by a decrease in the number of inappropriate injections. CONCLUSION: We present a simple, inexpensive simulation model for training in facet joint injections. The learning curves of our trainees using the simulator showed improvement in all of the parameters assessed.

Keywords: Zygapophyseal joint; Injections, intra-articular; Injections, spinal; Learning curve; Models, anatomic; Radiology, interventional.