Objective: To investigate the correlation between frontal regions cortical thickness measured by magnetic resonance imaging of HIV-positive patients and their performance on instruments for assessing executive functions. Materials and Methods: The present study included 22 HIV-positive patients in the age range from 45 to 65, schooling ranging between three and 20 years, with executive functions deficit and undergoing antiretroviral therapy. Magnetic resonance imaging was performed with conventional T1-weighted, 3D sequences and the images were processed with the Freesurfer software to measure cortical thickness. The following instruments were utilized to evaluate the patients' executive functions: Trail Making, Wisconsin, Hayling, working memory (WAIS-III), verbal fluency and Stroop tests. The Pearson's correlation coefficient was utilized in the data statistical analysis. Results: Significant correlations were found between: Wisconsin scores and the thickness of the right pre-central, lateral and left pre-central orbitofrontal regions; Trail Making scores and thickness of right pre-central and left anterior caudal cingulate areas; and Hayling Test scores and thickness of the left lateral orbitofrontal area. Conclusion: Correlations between cortical thickness measurements by magnetic resonance imaging and cognitive performance suggest that the executive function deficit in HIV-positive patients are related to a reduction in the thickness of the frontal cortex.

Keywords: Magnetic resonance imaging; Cortical thickness; Frontal lobe; Neuropsychological; Executive functions; HIV.

Objective: To evaluate the role of ultrasonography in the assessment of histopathological changes in patients with chronic hepatitis C, with emphasis on hepatic steatosis. Materials and Methods: Liver ultrasonography results were compared with histopathological findings of liver biopsy of 192 patients with chronic hepatitis C virus infection. All the US examinations followed a single protocol, analyzing the following aspects: echogenicity, echotexture and attenuation. The patients sample was divided into two groups as follows: patients with sonographic changes and patients with no sonographic changes. Sonographic findings of both groups were compared with histopathological findings after liver biopsy. Results: Statistically significant intergroup differences were observed just regarding architectural changes grades 0 and 3 and hepatic steatosis. Attenuation was the sonographic criterion that was best correlated with hepatic steatosis. Conclusion: The results of the present study demonstrate that, in patients with chronic hepatitis C, ultrasonography has limitations in the characterization of histopathological changes, with an intermediate rate of agreement with the diagnosis of hepatic steatosis. Considering the specificity of 77.9% and the negative predictive value of 95.5%, the authors highlight the capacity of the method to demonstrate the probability of absence of hepatic steatosis.

Keywords: Ultrasonography; Chronic hepatitis C virus infection; Hepatic steatosis; Liver biopsy.

Objective: To validate the proposal for development of a virtual collaborative environment for training of nuclear medicine personnel. Materials and Methods: Organizational assumptions, constraints and functionalities that should be offered to the professionals in this field were raised early in the development of the environment. The prototype was developed in the Moodle environment, including data storage and interaction functionalities. A pilot interaction study was developed with a sample of specialists in nuclear medicine. Users’ opinions collected by means of semi-structured questionnaire were submitted to quantitative and content analysis. Results: The proposal of a collaborative environment was validated by a community of nuclear medicine professionals and considered as an aid in the training in this field. Suggestions for improvements and new functionalities were made. There is a need to establish a program for education of moderators specifically for this environment, considering the different interaction characteristics as the online and conventional teaching methods are compared. Conclusion: The collaborative environment will allow the exchange of experiences and case discussions among professionals from institutions located in different regions all over the country, enhancing the collaboration among them. Thus, the environment can contribute in the early and continued education of nuclear medicine professionals.

Keywords: Collaborative environment; Nuclear medicine; Medical education; Distance education.

OBJECTIVE: To identify and evaluate the prevalence of congenital central nervous system (CNS) malformations and associated defects diagnosed by obstetric ultrasonography. MATERIALS AND METHODS: Observational, descriptive, crosssectional study developed in an institution of reference for high-risk pregnancies. RESULTS: Congenital CNS malformations without other associated defects were present in 65.78% of cases, as follows: hydrocephalus (37.5%), myelomeningocele (15%), encephalocele (12.5%), corpus callosum agenesis (12.5%), anencephaly (12.5%), holoprosencephaly (7.5%), Dandy-Walker (7.5%), Arnold-Chiari (5.0%), hydranencephaly (5.0%), meningocele (5.0%), arachnoid cyst (2.5%). Congenital malformations of other systems were associated with such malformations, as follows: craniofacial (73.9%), orthopedic (65.2%), cardiovascular (34.8%), genitourinary (30.4%), gastrointestinal (30.4%), respiratory (8.7%), syndromic (8.7%), ophthalmologic (4.3%). The sonographic sensitivity in the study of CNS malformations was 79.4%. The rate of false-negative results was 20.5%. Oligohydramnios, present in 25% of false-negative studies, stands out among the quantifiable limitations. CONCLUSION: Obstetric ultrasonography presents good sensitivity in the screening for fetal CNS malformations, specially with the constant improvement and control of specialized methods such as Doppler and volumetric ultrasonography (3D/4D), contributing to consolidate its role as a modality of choice in this routine. Magnetic resonance imaging may play a supplementary role, providing information for an even better perinatal care.

Keywords: Congenital malformations; Central nervous system malformations; Associated malformations; Ultrasonography.

OBJECTIVE: To evaluate the role of PET/CT in the approach to patients with head and neck cancer. MATERIALS AND METHODS: Retrospective study of medical records and PET/CT images of 63 patients with head and neck cancer. RESULTS: Alterations were observed in 76% of the cases. Out of these cases, 7 (11%) were considered as false-positive, with SUV < 5.0. PET/CT demonstrated negative results in 15 cases (24%). Among the 14 cases where the method was utilized for staging, 3 (22%) had their stages changed. CONCLUSION: PET/CT has shown to be of potential value in the routine evaluation of patients with head and neck cancer, but further studies of a higher number of cases are required to define a protocol for utilization of the method.

Keywords: Emission computed tomography; Fluorodeoxyglucose 18F; Head and neck neoplasms; Neoplasm staging; Squamous cell carcinoma.

OBJECTIVE: To evaluate sonographic features associated with morbidity in patients with chronic clinical presentations of schistosomiasis mansoni, according to the protocol proposed by the World Health Organization (WHO). Materials and Methods: Two distinctive populations were evaluated: a) patients from an endemic area, and b) patients from a tertiary institution, with histopathologically confirmed periportal fibrosis. INCLUSION CRITERIA: diagnosis confirmed by parasitological stool examination for Schistosoma mansoni (Kato-Katz method). EXCLUSION CRITERIA: positive serology for HIV, HTLV-1, HBV or HCV. The Niamey protocol on ultrasonography proposed by the WHO was utilized. RESULTS:As the measures of periportal spaces were isolatedly evaluated, no alteration was observed in 21% of the tertiary institution patients with advanced disease. As all parameters of the Niamey protocol were considered, 100% of patients from the tertiary institution, with severe disease, presented advanced periportal fibrosis. In hepatosplenic patients from endemic areas, fibrosis was not identified at ultrasonography. CONCLUSION: The sonographic protocol proposed by the WHO can detect advanced periportal fibrosis in patients with severe form of disease with higher sensitivity than the isolated measurement of periportal space. The complexity involved in the sonographic identification of early stages of periportal fibrosis in endemic areas may give rise to the field of diagnostic supplementation and to a continued improvement of sonographic protocols in these areas.

Keywords: Schistosomiasis mansoni; Morbidity; Periportal fibrosis; Ultrasonography.

OBJECTIVE: To evaluate the association of conventional angiography (AG) with computed tomography angiography (CTA) as compared with CTA only, preoperatively, in the treatment of aortic diseases. MATERIALS AND METHODS: Retrospective study involving patients submitted to endovascular treatment of aortic diseases, in the period from January 2009 to July 2010, with use of preoperative CTA + conventional AG or CTA only. The patients were divided into two groups, namely: G1 - thoracic aortic diseases; and G2 - abdominal aortic diseases. G1 was subdivided into 1A (preoperative AG + CTA) and 1B (preoperative CTA). G2 was subdivided into 2C (CTA + AG) and 2D (CTA only). RESULTS: The authors evaluated 156 patients. In subgroups 1A and 1B, the rate of technical success was, respectively, 100% and 94.7% (p = 1.0); and the rate of therapeutic success was, respectively, 81% and 58% (p = 0.13). A higher number of complications were observed in subgroup 1B (p = 0.057). The accuracy in the calculation of the prosthesis was higher in subgroup 1A (p = 0.065). In their turn, the rate of technical success in subgroups 2C and 2D was, respectively, 92.3% and 98.6% (p = 0.17). The rate of therapeutic success was 73% and 98.6% (p = 0.79). CONCLUSION: Preoperative conventional AG should be reserved for cases where CTA cannot provide all the information in the planning of a therapeutic intervention.

Keywords: Aneurysm; Vascular prosthesis; Angiography.

OBJECTIVE: The offering of high-technology radiotherapy to the population assisted by the Brazilian unified health system (SUS) is limited since it is not included in the system's list of procedures and, many times, because of the insufficient installed capacity and lack of specialized human resources. Thus the access to intensity-modulated radiotherapy (IMRT) is restricted to few centers in Brazil. The present study is aimed at presenting the characteristics of the first 508 cases treated with IMRT during the first years after the technique implementation in a university hospital. MATERIALS AND METHODS: The first consecutive 508 cases of IMRT treatment completed in the period from May/2011 to September/ 2013 were reviewed. Static multileaf was the technique employed. RESULTS: Amongst 4,233 treated patients, 12.5% were submitted to IMRT. Main indications for the treatment included cancers located in the skull, head and neck and prostate. Intensity modulated radiotherapy was utilized in about 30% of cranial and 50% of prostate treatments. Treatment toxicity was observed in 4% of the patients. CONCLUSION: Because of restricted access to radiotherapy in addition to lack of coverage for the procedure, IMRT indications for SUS patients should be based on institutional clinical protocols, with special attention to the reduction of toxicity.

Keywords: Radiotherapy; Unified Health System; SUS; IMRT.

OBJECTIVE: The present study was aimed at evaluating the viability of replacing ¹⁸F with ^99mTc in dose calibrator linearity testing. MATERIALS AND METHODS: The test was performed with sources of ^99mTc (62 GBq) and ¹⁸F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical ^99mTc and ¹⁸F sources activities were calculated and subsequently compared. RESULTS: Mean deviations between experimental and theoretical ^99mTc and ¹⁸F sources activities were 0.56 (± 1.79)% and 0.92 (± 1.19)%, respectively. The mean ratio between activities indicated by the device for the ^99mTc source as measured with the equipment pre-calibrated to measure ^99mTc and ¹⁸F was 3.42 (± 0.06), and for the ¹⁸F source this ratio was 3.39 (± 0.05), values considered constant over the measurement time. CONCLUSION: The results of the linearity test using ^99mTc were compatible with those obtained with the ¹⁸F source, indicating the viability of utilizing both radioisotopes in dose calibrator linearity testing. Such information in association with the high potential of radiation exposure and costs involved in ¹⁸F acquisition suggest ^99mTc as the element of choice to perform dose calibrator linearity tests in centers that use ¹⁸F, without any detriment to the procedure as well as to the quality of the nuclear medicine service.

Keywords: Nuclear medicine; Dose calibrator; Linearity test; Nuclear instrumentation.

OBJECTIVE: To determine common imaging findings of hepatic epithelioid hemangioendothelioma on magnetic resonance images. MATERIALS AND METHODS: A search was made of three institutional databases between January 2000 and August 2012. Seven patients (mean age, 47 years; range, 21–66 years; 6 women) with pathology-confirmed diagnosis of hepatic epithelioid hemangioendothelioma who had undergone magnetic resonance imaging were identified. None of the patients had received any treatment for hepatic epithelioid hemangioendothelioma at the time of the initial magnetic resonance imaging examination. RESULTS: Hepatic epithelioid hemangioendothelioma tumors appeared as focal masses in 7/7 patients, greater than 5 in number, with a coalescing lesion in 1/5, and peripheral localization in 6/7. Capsular retraction was present in 4/7, and was associated with peripherally located lesions. Early ring enhancement was appreciated in the majority of lesions in 7/7 patients. Centripetal progressive enhancement was shown in 5/7 patients on venous phase that exhibited a distinctive thick inner border of low signal on venous phase images, and a central core of delayed enhancement. Small lesions did not show this. CONCLUSION: The combination of multifocal round-configuration lesions that are predominantly peripheral and exhibit early peripheral ring enhancement and late appearance of an inner thick border of low signal and central core of high signal may represent an important feature for hepatic epithelioid hemangioendothelioma.

Keywords: Liver neoplasms/diagnosis; Epithelioid hemangioendothelioma; Magnetic resonance imaging.

OBJECTIVE: To test the accuracy and reproducibility of ultrasound and computed tomography (CT) for the quantification of abdominal fat in correlation with the anthropometric, clinical, and biochemical assessments. MATERIALS AND METHODS: Using ultrasound and CT, we determined the thickness of subcutaneous and intra-abdominal fat in 101 subjects—of whom 39 (38.6%) were men and 62 (61.4%) were women—with a mean age of 66.3 years (60-80 years). The ultrasound data were correlated with the anthropometric, clinical, and biochemical parameters, as well as with the areas measured by abdominal CT. RESULTS: Intra-abdominal thickness was the variable for which the correlation with the areas of abdominal fat was strongest (i.e., the correlation coefficient was highest). We also tested the reproducibility of ultrasound and CT for the assessment of abdominal fat and found that CT measurements of abdominal fat showed greater reproducibility, having higher intraobserver and interobserver reliability than had the ultrasound measurements. There was a significant correlation between ultrasound and CT, with a correlation coefficient of 0.71. CONCLUSION: In the assessment of abdominal fat, the intraobserver and interobserver reliability were greater for CT than for ultrasound, although both methods showed high accuracy and good reproducibility.

Keywords: Abdominal fat; Ultrasonography; Computed tomography; Radiology.

OBJECTIVE: To compare intraoperative measurements of the knee with those obtained by magnetic resonance imaging, in order to validate the latter method for use in anthropometric studies. MATERIALS AND METHODS: We studied 20 knees in 20 patients with osteoarthritis, all of whom underwent total arthroplasty between August and December of 2013. We took six measurements in the distal femur and two in the proximal tibia. Using the information system of the institution, we made the measurements on magnetic resonance imaging scans that had been obtained in the axial plane. Intraoperative measurements were obtained using a caliper, after the initial cuts made during the arthroplasty. The anatomical parameters determined by magnetic resonance imaging were the same as those determined by intraoperative measurement. The intraclass correlation coefficient was used in order to assess the level of agreement in anthropometric measurements of the knee performed by magnetic resonance imaging and by intraoperative measurement. RESULTS: Statistical analysis revealed a highly significant correlation between the knee anthropometric parameters of the knee determined by intraoperative measurement and those determined by magnetic resonance imaging. CONCLUSION: The dimensions of osteoarthritic knees measured by magnetic resonance imaging were similar to those measured intraoperatively. Therefore, magnetic resonance imaging can be considered a reliable method for use in large-scale anthropometric studies that will allow the available implants to be adapted and improved.

Keywords: Knee; Diagnostic imaging; Magnetic resonance imaging; Prostheses; Osteoarthritis; Anthropometry.

OBJECTIVE: To establish an overview of computed tomography (CT)-guided percutaneous nephrostomy performed at a referral center for cancer, addressing the characteristics of patients submitted to this intervention, as well as the indications for it, the technical specificities of it, and its main complications. MATERIALS AND METHODS: This was a retrospective study involving a review of the electronic medical records and images of patients submitted to CT-guided percutaneous nephrostomy at a referral center for cancer between 2014 and 2016. RESULTS: A total of 201 procedures were evaluated. In most cases, the obstruction was caused by a malignant neoplasm. Complications occurred in 9.5% of the cases, and an additional intervention was required (typically for catheter repositioning) in 36.6%. Post-procedure complications were not found to be significantly associated with the type of previous cancer treatment, the technique used, the caliber of the drain used in the procedure, or the degree of dilatation of the collection system prior to the procedure. CONCLUSION: In cancer patients, CT-guided percutaneous nephrostomy is an effective treatment, with success rates and complication rates similar to those reported in the general population.

Keywords: Nephrostomy, percutaneous/methods; Nephrostomy, percutaneous/adverse effects; Computed tomography.

OBJECTIVE: To evaluate the usefulness of elastography (using manual compression) as an additional diagnostic tool for children and adolescents with thyroid nodules. MATERIALS AND METHODS: This was a prospective study conducted between September 2012 and August 2013 at a hospital in Brazil. We performed elastography, ultrasound, and fine-needle aspiration biopsy in 32 patients between 6 and 18 years of age who had, in total, 38 thyroid nodules. RESULTS: The elastography findings correlated with the histopathological diagnosis in 78.5% of cases. In three patients, an unnecessary thyroidectomy could have been avoided if the elastography results had been prioritized. Only one malignant thyroid nodule was found to show high elasticity. CONCLUSION: Our results suggest that high elasticity of a nodule on elastography is associated with a low risk of thyroid cancer. If further confirmed in other studies, elastography may prove useful as a complementary test for screening thyroid nodules in children.

Keywords: Thyroid neoplasms; Child; Thyroid nodule/diagnostic imaging; Elasticity imaging techniques; Ultrasonography.

OBJECTIVE: To evaluate the imaging findings of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and computed tomography (CT) in patients with additional primary tumors, correlating the results with those of the method used in order to elucidate the diagnosis and of the pathology reports. MATERIALS AND METHODS: We retrospectively analyzed the medical records, pathology reports and images of 11 patients who underwent CT, ¹⁸F-FDG PET/CT, or both. We included patients with at least two tumors, with confirmed distinct histopathological profiles, at different sites. Patients in whom there was no diagnostic confirmation were excluded, as were those in whom the additional lesion was suspected of being a metastasis of the first. RESULTS: New primary malignancies were identified in 11 patients, one new tumor being found in 10 and two new tumors being found in 1. The confirmed sites of the additional malignancies were the lung, kidney, prostate, jejunum, and breast. Single or multiple percutaneous biopsies were performed in 10 patients, and 1 patient underwent a surgical procedure for diagnostic and therapeutic purposes. The tumors were metachronous in 6 cases and synchronous in 5. CONCLUSION: CT and ¹⁸F-FDG PET-CT combined with multiple percutaneous biopsy could facilitate the diagnosis of additional lesions, thus optimizing the treatment and follow-up of the affected patients.

Keywords: Neoplasms, second primary/etiology; Biopsy, needle/methods; Positron-emission tomography/methods; Tomography, X-ray computed/methods; Fluorodeoxyglucose F18.

OBJECTIVE: To evaluate the accuracy of percutaneous transhepatic biliary biopsy (PTBB) in patients with suspected biliary obstruction. MATERIALS AND METHODS: This was a retrospective analysis of 18 patients with obstructive jaundice who underwent PTBB. In each patient, three to ten fragments were collected from the lesion. The final diagnosis was confirmed in the pathology report. We also reviewed analyses of the results of laboratory tests performed before the procedure, as well as the Bismuth classification, clinical outcome, complications occurring during the procedure, access route, and materials used. RESULTS: Technical success was achieved in 100% of the PTBB procedures. Among the 18 patients clinically diagnosed with bile duct stenosis, the pathological analysis confirmed that diagnosis in 17. In one case, the pathological findings were considered false-negative. The predominant tumor was cholangiocarcinoma (seen in 50% of the cases). Sixteen of the procedures (88.9%) were performed without complications. Transient hemobilia occurred in one case, and cholangitis occurred in another. CONCLUSION: PTBB is a safe, viable, simple technique with a high rate of true-positive results for the definitive diagnosis of obstructive jaundice.

Keywords: Jaundice, obstructive; Biliary tract; Biopsy/methods; Biopsy, needle/methods; Cholangiography.

OBJECTIVE: To compare two percutaneous techniques used in the treatment of malignant obstructive uropathy—antegrade double-J stent placement (JJ stenting) and percutaneous nephrostomy—in terms of their cost-effectiveness, from the perspective of the Brazilian public health care system. MATERIALS AND METHODS: In this cost-effectiveness analysis, we employed decision-analytic modeling. We calculated material costs from 2017 factory prices listed by the Brazilian Pharmaceutical Market Regulatory Board (for medications) and published in the journal Revista Simpro (for medical devices). Procedure-related costs were evaluated, as were the rates of technical and clinical success. Those measures were then used as inputs for a cost-effectiveness analysis comparing the two procedures. RESULTS: The sample comprised 41 patients, of whom 16 underwent antegrade JJ stenting (26 procedures) and 10 underwent percutaneous nephrostomy (15 procedures). Patient records, radiology reports, and expense reports of the interventional radiology department of the public hospital where the study was conducted were analyzed retrospectively. There were no significant complications: one patient had low back pain, and one had a transient retroperitoneal hematoma. The mean procedure time was 24 min, and clinical success (improvement in serum creatinine and resolution of hydronephrosis) was achieved in 97.5% of the cases. The average cost of JJ stenting was significantly lower than was that of percutaneous nephrostomy (US$164.10 vs. US$552.20). CONCLUSION: In the absence of any clinical contraindications, antegrade JJ stenting is a suitable alternative to both percutaneous nephrostomy and retrograde stenting in patients with dilated renal collecting systems secondary to malignant ureteral obstruction, providing significant cost savings and high success rates.

Keywords: Cost-benefit analysis; Radiology, interventional; Nephrostomy, percutaneous; Stents.

OBJECTIVE: To perform a quantitative analysis of the brain volume of elderly individuals in a population-based sample. MATERIALS AND METHODS: This was a radiological assessment and voxel-based quantitative analysis, with surface alignment, of 525 magnetic resonance imaging scans of individuals between 60 and 103 years of age who participated in the Saúde, Bem-estar e Envelhecimento (Health, Well-being, and Aging) study in the city of São Paulo, Brazil. RESULTS: We noted a median rate of reduction in total brain volume of 2.4% per decade after 60 years of age. Gray and white matter both showed volume reductions with age. The total brain volume/intracranial brain volume ratio differed between males and females. CONCLUSION: We have corroborated the findings of studies conducted in the United States and Europe. The total brain volume/intracranial brain volume ratio is higher in men, representing a potential bias for the conventional radiological assessment of atrophy, which is typically based on the evaluation of the cerebrospinal fluid spaces.

Keywords: Aging; Brain; Magnetic resonance imaging; Neuroimaging; Image interpretation, computer-assisted/methods.

OBJECTIVE: To investigate whether quantitative computed tomography (CT) measurements can predict microvascular invasion (MVI) in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This was a retrospective analysis of 200 cases of surgically proven HCCs in 125 consecutive patients evaluated between March 2010 and November 2017. We quantitatively measured regions of interest in lesions and adjacent areas of the liver on unenhanced CT scans, as well as in the arterial, portal venous, and equilibrium phases on contrast-enhanced CT scans. Enhancement profiles were analyzed and compared with histopathological references of MVI. Univariate and multivariate logistic regression analyses were used in order to evaluate CT parameters as potential predictors of MVI. RESULTS: Of the 200 HCCs, 77 (38.5%) showed evidence of MVI on histopathological analysis. There was no statistical difference between HCCs with MVI and those without, in terms of the percentage attenuation ratio in the portal venous phase (114.7 vs. 115.8) and equilibrium phase (126.7 vs. 128.2), as well as in terms of the relative washout ratio, also in the portal venous and equilibrium phases (15.0 vs. 8.2 and 31.4 vs. 26.3, respectively). CONCLUSION: Quantitative dynamic CT parameters measured in the preoperative period do not appear to correlate with MVI in HCC.

Keywords: Carcinoma, hepatocellular; Tomography, X-ray computed; Liver neoplasms/surgery; Liver transplantation.