OBJECTIVE: To demonstrate the frequency of malignancy and histological characteristics of lesions in patients submitted to vacuum-assisted breast biopsy guided by magnetic resonance imaging (MRI). MATERIALS AND METHODS: This was a retrospective study of MRI-guided vacuum-assisted breast biopsies performed between April 2008 and December 2016, in which we analyzed clinical and epidemiological data, as well as the BI-RADS classification and histopathological results. We compared nodules and non-nodular enhancements, in terms of their correlation with malignancy, using chi-square test. RESULTS: Among 215 cases referred for MRI-guided vacuum-assisted breast biopsy, the procedure was contraindicated in 10 cases (5%) and was technically feasible in the remaining 205 (95%). Non-nodular enhancements were observed in 135 cases (66%), and nodules were observed in 70 (34%), with a mean diameter of 2.2 cm (range, 0.5-9.6 cm) and 0.97 cm (range, 0.5-2.2 cm), respectively. Of the 205 lesions analyzed, 43 (21%) were malignant, 129 (63%) were benign, and 33 (16%) were classified as high-risk lesions. The most common histological findings were invasive ductal carcinoma and, in high-risk cases, lobular neoplasia. There was no significant difference between nodules and non-nodular enhancements in terms of the rate of malignancy (p = 0.725). CONCLUSION: In our sample, the overall malignancy rate was 21%. However, to improve the assessment of these results, it is necessary to correlate them with the surgical data and with data from the follow-up of benign cases.

Keywords: Image-guided biopsy/methods; Breast; Magnetic resonance imaging; Breast neoplasms/diagnosis.

OBJECTIVE: To assess the accuracy of ultrasound in the visualization of the brachial plexus and to determine the value of the method in comparison with that of magnetic resonance imaging (MRI). MATERIALS AND METHODS: This was an anatomical study of the brachial plexuses of 20 asymptomatic adults (40 plexuses), comparing ultrasound and MRI in terms of their accuracy. In the ultrasound study, a high-frequency linear transducer was used, and a neurovascular coil was used in the MRI study. To estimate the frequency of visualization, the brachial plexus was divided into segments. RESULTS: The cervical nerve roots, the upper trunk, and the middle trunk were the segments that were best visualized on ultrasound. On MRI, the degree of visualization was excellent for most of the segments. In the comparison between ultrasound and MRI, the C6, C7, upper trunk, and middle trunk segments showed equivalent degrees of visualization, with a high level of agreement between the two methods. CONCLUSION: In the brachial plexus, ultrasound can be used in the assessment of the cervical nerve roots, as well as of the upper and middle trunks, although it provides limited visualization of the remaining segments. Ultrasound and MRI showed a high level of agreement for the visualization of the C6, C7, and middle trunk segments.

Keywords: Brachial plexus/anatomy & histology; Ultrasonography; Magnetic resonance imaging.

OBJECTIVE: To describe head computed tomography (CT) findings in neonates with congenital Zika virus infection confirmed in cerebrospinal fluid. MATERIALS AND METHODS: This was a study of 16 newborn infants who exhibited abnormal head CT findings during an outbreak of Zika virus infection. Those infants had the following features: brain imaging suggestive of congenital infection; brain calcifications and negative results on tests for other main infectious causes of primary microcephaly, namely toxoplasmosis, cytomegalovirus, rubella, and HIV; positivity for Zika virus on IgM antibody capture enzyme-linked immunosorbent assay in cerebrospinal fluid. RESULTS: Decreased brain volume was observed in 13 (81.2%) of the infants. All of the infants showed cortico-subcortical calcifications, mainly located in the frontal lobe. In 15 neonates (93.7%), ventriculomegaly was observed. Colpocephaly was a common finding, being observed in 10 patients (62.5%). A prominent occipital bone was identified in 9 patients (56.2%). CONCLUSION: Our study proves that Zika virus infection can cause congenital brain damage, with or without microcephaly. Some predominant head CT findings in neonates with congenital Zika virus infection, although not pathognomonic, are strongly suggestive of a pattern.

Keywords: Skull; Tomography, X-ray computed; Zika virus; Communicable diseases, emerging; Infant, newborn.

OBJECTIVE: To assess changes in the great saphenous vein (GSV) after foam sclerotherapy for varicose veins. MATERIALS AND METHODS: This was a prospective study of 33 patients who were treated with polidocanol foam sclerotherapy after having had varicose veins with a clinical severity-etiology-anatomy-pathophysiology classification of C4-C6 for three months. The patients were evaluated by ultrasound before, during, and after the procedure (on post-procedure days 7, 15, 30, 60, and 90). The GSV diameter, the rate of venous occlusion, and the rate of reflux elimination were determined. Two patients were excluded for having a history of deep vein thrombosis history, and one was excluded for having bronchial asthma. RESULTS: Thirty patients (26 females and 4 males, with mean age of 62 years) completed the protocol. The mean pre-procedure GSV diameter was 6.0 ± 0.32 mm (range, 3.6-11.2 mm). During the sclerotherapy, the mean GSV diameter was reduced to 1.9 ± 0.15 mm (range, 0.6-3.8 mm). On post-procedure day 7, the mean GSV diameter increased to 6.3 ± 0.28 mm (range, 3.9-9.7 mm). On post-procedure day 90, the mean GSV diameter was 4.0 ± 0.22 mm (range, 1.9-8.2 mm). The rate of GSV reflux was significantly lower in the assessment performed on post-procedure day 90 than in the pre-procedure assessment (p < 0.0028). CONCLUSION: On the basis of our ultrasound analysis, we can conclude that foam sclerotherapy for varicose veins results in a significant reduction in GSV diameter, as well as in the elimination of GSV reflux.

Keywords: Ultrasonography; Varicose veins; Sclerotherapy; Saphenous vein; Venous insufficiency.

OBJECTIVE: To determine whether dual-energy computed tomography (DECT) of the chest can be performed at a reduced radiation dose, with an emphasis on images generated with post-processing techniques. MATERIALS AND METHODS: In 21 patients undergoing DECT of the chest in a dual-source scanner, an additional image series was acquired at a reduced radiation dose. Four thoracic radiologists assessed both image series for image quality, normal thoracic structures, as well as pulmonary and mediastinal abnormalities, on virtual monochromatic images at 40 keV and 60 keV. Data were analyzed with Student’s t-test, kappa statistics, analysis of variance, and the Wilcoxon signed-rank test. RESULTS: The overall image quality of 60 keV virtual monochromatic images at a reduced radiation dose was considered optimal in all patients, and no abnormalities were missed. Contrast enhancement and lesion detection performance were comparable between reduced-dose images at 40 keV and standard-of-care images at 60 keV. The intraobserver and interobserver agreement were both good. The mean volumetric CT dose index (CTDIvol), size-specific dose estimate (SSDE), dose-length product (DLP), and effective dose (ED) for reduced-dose DECT were 3.0 ± 0.6 mGy, 4.0 ± 0.6 mGy, 107 ± 30 mGy.cm, and 1.5 ± 0.4 mSv, respectively. CONCLUSION: DECT of the chest can be performed at a reduced radiation dose (CTDIvol < 3 mGy) without loss of diagnostic information.

Keywords: Radiation dose reduction; Dual energy computed tomography; Monochromatic images.

OBJECTIVE: To evaluate the use of pulmonary inhalation-perfusion scintigraphy as an alternative method of investigation and follow-up in patients with bronchopleural fistula (BPF). MATERIALS AND METHODS: Nine patients with BPFs were treated through the off-label use of a transcatheter atrial septal defect occluder, placed endoscopically, and were followed with pulmonary inhalation-perfusion scintigraphy, involving inhalation, via a nebulizer, of 900-1300 MBq (25-35 mCi) of technetium-99m-labeled diethylenetriaminepentaacetic acid and single-photon emission computed tomography with a dual-head gamma camera. RESULTS: In two cases, there was a residual air leak that was not identified by bronchoscopy or the methylene blue test but was detected only by pulmonary inhalation-perfusion scintigraphy. Those results correlated with the evolution of the patients, both of whom showed late signs of air leak, which confirmed the scintigraphy findings. In the patients with complete resolution of symptoms and fistula closure seen on bronchoscopy, the scintigraphy was completely negative. In cases of failure to close the BPF, the scintigraphy confirmed the persistence of the air leak. In two patients, scintigraphy was the only method to show residual BPF, the fistula no longer being seen on bronchoscopy. CONCLUSION: We found pulmonary inhalation-perfusion scintigraphy to be a useful tool for identifying a residual BPF, as well as being an alternative method of investigating BPFs and of monitoring the affected patients.

Keywords: Radionuclide imaging/methods; Radioactive tracers; Bronchial fistula; Septal occluder device; Lung.

Primary retroperitoneal masses constitute a heterogeneous group of uncommon lesions and represent a challenge due to overlapping imaging findings. Most are malignant lesions. Although they are more prevalent in adults, they can occur at any age. Such lesions are classified as primary when they do not originate from a specific retroperitoneal organ and are divided, according to the image findings, into two major groups: solid and cystic. The clinical findings are nonspecific and vary depending on the location of the lesion in relation to adjacent structures, as well as on its behavior. The main imaging methods used for staging and surgical planning, as well as for selecting the biopsy site and guiding the biopsy procedure, are computed tomography and magnetic resonance imaging. In most cases, the treatment is challenging, because of the size of the lesions, vascular involvement, or involvement of adjacent organs. In this article, we present a review of the retroperitoneal anatomy and a practical approach to the main imaging features to be evaluated, with a view to the differential diagnosis, which can guide the clinical management.

Keywords: Retroperitoneal space/anatomy & histology; Retroperitoneal neoplasms/diagnosis; Tomography, X-ray computed; Magnetic resonance imaging.

Sarcomas of the breast belong to a heterogeneous group of breast tumors of mesenchymal origin, without epithelial components. These tumors can be primary or secondary (after previous treatment for breast cancer), are rare, present aggressive behavior, and have a poor prognosis. They occur mainly in women between 45 and 50 years of age, with the exception of angiosarcomas, which can occur in younger patients. Clinically, breast sarcomas manifest as palpable, mobile, rapidly growing masses, without skin thickening, axillary lymphadenopathy, or nipple discharge. Although the imaging findings are non specific, they can be suggestive of sarcoma. For instance, a solitary mass showing rapid growth, with circumscribed or indistinct margins and, a complex (solid-cystic) or heterogeneous echotexture, without axillary lymph node involvement, can raise the suspicion of sarcoma. The treatment is not well established, because of the rarity and heterogeneity of this type of neoplasm. The principles of treatment for sarcoma of the breast have been addressed only in small cohort studies. In most cases, the treatment of choice is surgery without axillary lymphadenectomy.

Keywords: Breast cancer; Sarcoma; Mammography; Ultrasonography; Magnetic resonance imaging.