OBJECTIVE: The objective of this study was to describe chest computed tomography findings in confirmed cases of infection by the novel influenza A (H1N1) virus. MATERIALS AND METHODS: Computed tomography studies of nine patients with laboratory-confirmed infection by the novel influenza A (H1N1) virus were consensually evaluated by three observers. The sample of the present study included five male and four female patients with ages ranging from 14 to 64 years (mean, 40 years). Four of the patients were previously healthy, four were kidney transplant recipients and one was pregnant at the time of diagnosis. Presence, extent and distribution of the following findings were evaluated: a) ground-glass opacities; b) centrilobular nodules; c) consolidation; d) interlobular septa thickening; e) pleural effusion; f) lymphadenopathy. RESULTS: The most frequent findings were ground-glass opacities, centrilobular nodules and consolidations, present in nine (100%), five (55%) and four (44%) of cases, respectively. Pleural effusions and lymphadenopathy were less common findings, occurring in only two (22%) of the cases. CONCLUSION: Ground-glass opacities, centrilobular nodules and consolidation were the most frequent findings in cases of infection by the novel influenza A (H1N1) virus. These changes are not typical or unique to this agent and may also occur in other viral or bacterial infections.

Keywords: Influenza A virus, Influenza A (H1N1) virus subtype, Viral pneumonia, X-ray computed tomography

OBJECTIVE: The present study is aimed at comparing the quality of sonographic abdominal images obtained in fasting and non fasting children. MATERIALS AND METHODS: This is a prospective study including children aged up to 12 years sequentially evaluated by two sonographers. The images were classified according to a score as follows: 1 (non-visualized or partially visualized, inappropriate for diagnosis); 2 (sufficient for diagnosis); or 3 (excellent). Images were also classified into "diagnostic" or "non diagnostic". RESULTS: Seventy-seven patients (47 boys and 30 girls) with ages ranging between 0 and 12 years (median = 1 year) were evaluated. Fasting proved a statistically significant advantage only for evaluating the gallbladder by only one of the observers (p = 0.032). Once the images were classified into either "diagnostic" or "non diagnostic" no difference was observed between the two groups. CONCLUSION: The authors conclude that fasting did not affect significantly the quality of abdominal sonographic images in children.

Keywords: Ultrasonography, Children, Abdominal, Fasting

OBJECTIVE: The purpose of this study was to evaluate the interobserver variability of ultrasound in the measurement of subcutaneous, visceral and perirenal fat through standard technique. MATERIALS AND METHODS: From November 2006 to January 2007, 50 patients were evaluated. The subcutaneous fat thickness was measured with a 7.5 MHz linear transducer transversely positioned 1 cm above the umbilical scar. For the visceral fat, a 3.5 MHz transducer was also positioned 1 cm above the umbilical scar, considering the distance between the internal surface of the abdominal rectus muscle and the posterior aortic wall in the abdominal midline. The perirenal fat was measured in the middle third of the right kidney, with the transducer positioned at the axillary midline. RESULTS: The t-Student test was utilized to analyze the interobserver reproducibility with significance level of 95%. No statistically significant difference was observed among mean values for subcutaneous, visceral and perirenal fat (p = 0.7141, 0.7286 and 0.6368, respectively). Mean and standard deviation corresponded to 2.64 ± 1.37 for subcutaneous thickness, 6.84 ± 2.38 for visceral fat, and 4.89 ± 2.6 for perirenal fat. CONCLUSION: Ultrasound presented a good interobserver reproducibility in the evaluation of abdominal fat based on measurement of subcutaneous, visceral and perirenal fat as parameters.

Keywords: Abdominal fat, Ultrasound, Metabolic syndrome

OBJECTIVE: To evaluate the correlation between the yolk sac volume measured by three-dimensional ultrasonography with gestational age at 7-10 weeks. MATERIALS AND METHODS: A cross-sectional study involving 72 healthy pregnant women at 7th-10th gestational weeks. The multiplanar method with 1.0 mm intervals was utilized. Regression models were constructed to analyze the correlation between yolk sac volume and gestational age, adjusted by the determination coefficient (R²). Mean, median, standard deviation, maximum and minimum values for yolk sac volume were calculated for each gestational age. RESULTS: A poor correlation was observed between yolk sac volume (YSV) and gestational age (GA). The quadratic regression was the model that best expressed this correlation: YSV = 0.9757 - 0.2499 × GA + 0.0172 × GA² (R² = 0.234). Mean yolk sac volume ranged from 0.07 cm³ (0.02-0.11) to 0.20 cm³ (0.02-0.74) between the 7th and 10th weeks (mean, 0.11 cm³, ± 0.10 cm³). CONCLUSION: There was a poor correlation between yolk sac volume and gestational age.

Keywords: Yolk sac, First trimester of pregnancy, Gestational age, Prenatal ultrasonography, Three-dimensional imaging

OBJECTIVE: The purpose of this study was to assess the features of breast lesion texture on sonographic images of patients submitted to breast-conserving surgery, with or without tumor recurrence. MATERIALS AND METHODS: Sonographic images of 36 patients submitted to conservative surgery for breast cancer, 12 of them with, and 24 without local recurrence, included 3 contralateral malignant lesions, 7 benign lumps (3 cysts and 4 fibroadenomas), 5 atypical hyperplasias and 9 fibrocystic changes. The quantification of features of breast lesion texture was based on ten parameters calculated from gray-level co-occurrence matrix and complexity curve. Linear discriminant analysis was applied to the texture parameters for differentiating between breast lesions in women submitted to conservative surgery with and without tumor recurrence. RESULTS: The assessment of performance of texture parameters in distinguishing lesion recurrences in a group including benign lumps and atypical hyperplasias demonstrated specificity of 100%, and accuracy and sensitivity > 91%. Another test demonstrated that texture parameters were useful in the differentiation between atypical hyperplasias and benign lumps. CONCLUSION: Despite the limited number of cases, the present results can be considered as promising, suggesting that texture parameters may help in the differentiation among benign lumps, atypical hyperplasias and recurrent malignant lesions.

Keywords: Computer-assisted image processing, Computer-assisted image interpretation, Computer-assisted decision making, Recurrence, Breast ultrasonography

OBJECTIVE: To evaluate main imaging findings of subungual glomus tumors. MATERIALS AND METHODS: Retrospective study of eight cases of subungual glomus tumors from the archives of two private clinics in Goiânia, GO, Brazil. Plain radiographs were obtained in five cases, Doppler ultrasonography in five, and magnetic resonance imaging in five cases. RESULTS: Mean age of the patients included in the present study was 39 years, with female predominance (7:1). Tumors didn't present prevalence in any specific finger and in most of cases the tumor was located in the medial subungual region. Plain radiography was positive in five cases, demonstrating pressure erosion. Doppler ultrasonography was positive in five cases, demonstrating a hypoechoic and hypervascularized solid nodule. Magnetic resonance imaging was positive in all of the cases, showing a solid nodule, hypointense on T1-, hyperintense on T2-weighted image, with homogeneous contrast uptake. All the patients underwent surgical excision of the lesion with histopathological confirmation. CONCLUSION: In most of cases, glomus tumors are subungual. The diagnosis is clinical and generally is lately achieved. Imaging methods are useful tools for the early diagnosis besides aiding in the surgical planning, considering that the treatment of choice is surgical excision.

Keywords: Subungual glomus tumors, Magnetic resonance imaging, Ultrasonography

OBJECTIVE: The objective of the present study is to analyze the optimization of fluoroscopic image quality and patient entrance surface air kerma rate in interventional radiology procedures, utilizing a phantom adapted for fluoroscopy. MATERIALS AND METHODS: The authors utilized a phantom developed for evaluating conventional radiological images adapted for fluoroscopy through the addition of two catheters with different diameters, both of them utilized in interventional radiology. The patient entrance surface air kerma rate was determined with the aid of this phantom. RESULTS: The evaluation of technical parameters for different exposure modes of a digital fluoroscopic imaging system has allowed the determination of the air kerma rate, enabling the optimization of the image quality in interventional procedures. The decrease in the patient entrance surface air kerma rate may achieve 67%. CONCLUSION: The optimization of fluoroscopic image quality achieved with a phantom allows reducing the patient entrance surface air kerma with no significant loss of diagnostic performance.

Keywords: Images optimization, Fluoroscopy, Phantom, Dose reduction

OBJECTIVE: The purpose of thys study was to investigate the effect of the addition of aluminum (1 mm) and copper (0.4 mm) filters on effective radiation doses and image quality in videofluoroscopy. MATERIALS AND METHODS: An ionization chamber coupled with an electrometer was added to x-ray tube to measure the kerma area product with 65 kV and 0.7 mA technique, without and with additional filtration. Low contrast, gray scale and spatial resolution were measured utilizing Leeds test objects. Fifteen volunteers underwent pharynx study, ten without and five with aluminum and cooper filters associated, and had the kerma area product/minute compared. RESULTS: The specified filters addition, either separated or associated, allowed an expressive decrease in kerma area product besides an actual improvement in the videofluoroscopic images quality determined by a better gray tones differentiation and increased brightness contrast ratio in the gray curve. CONCLUSION: Additional aluminum and copper filters interposition, especially when associated, results in improved image quality with expressive reduction in the required radiation doses.

Keywords: Videofluoroscopy, Kerma area product, X-ray, Radiological image, Radiation dose

OBJECTIVE: The present study was aimed at evaluating the practical peak voltage (PPV) determined from the voltage waveform applied to x-ray tubes and comparing it with some kVp definitions for different types of x-ray equipment: single-phase (full-wave) and three-phase (six-pulse) clinical x-ray generators, and an industrial constant potential apparatus. MATERIALS AND METHODS: The study involved the comparison between invasively measured PPV (with voltage dividers) and values obtained with two commercial noninvasive meters, besides values of other quantities utilized for measuring the x-ray tube peak voltage. The PPV variation with the voltage ripple was also analyzed in the present study. RESULTS: The authors observed that the difference between PPV and the most common peak voltage definitions increases with the ripple. PPV values varied up to 3% and 5%, respectively, in the comparison between invasive and non-invasive measurements with single-phase and three-phase devices. CONCLUSION: The results demonstrated that voltage ripple is the main quantity influencing the invasive or non-invasive PPV determination. Additionally, non-invasively measured PPV values should be evaluated taking into consideration their dependence on the data sample rate and waveform obtained by the device.

Keywords: Practical peak voltage, X-ray tubes, Voltage divider, Voltage waveform, Peak voltage, kVp meters

The knowledge of uterine and ovarian changes in the puberty is essential in the investigation changes in the female pelvis of children and teenagers. In these patients, pelvic ultrasonography is routinely performed with a full bladder to produce an acoustic window, although this examination may also be performed with endovaginal approach in sexually active teenagers. Main indications for pelvic ultrasonography in children and teenagers are either early or delayed puberty, pelvic pain or tumors, ambiguous genitalia, vaginal bleeding in children, and primary amenorrhea. In the present paper, the authors describe the scanning technique and the most frequent sonographic findings.

Keywords: Ultrasonography, Early puberty, Ovary

Retrospective study of two cases of atypically localized cerebral hemorrhage among 777 newborns admitted to the neonatal intensive care unit at Casa de Saúde São José, Rio de Janeiro, RJ, Brazil. Clinical findings and imaging diagnoses were evaluated. The diagnostic effectiveness of ultrasonography was established by correlation with magnetic resonance imaging findings. Multifactorial etiology was observed, besides silent clinical presentation independently from localization. So far the neurological evaluation has satisfactorily progressed although the patients are still too young to allow a definite neurological evaluation.

Keywords: Brain, Newborn, Atypical hemorrhage, Posterior fossa hemorrhage, Ultrasonography, Magnetic resonance imaging

Many reports in the literature have described findings of gossypibomas at conventional radiography and computed tomography. However, magnetic resonance imaging findings are still to be completely known. The purpose of the present study was to describe imaging findings of gossypibomas in a patient with previous history of brain surgery, presenting fever and mental confusion.

Keywords: Magnetic resonance imaging, Brain, Granuloma, Gossypiboma