The combination of positron emission tomography (PET) with magnetic resonance imaging (MRI) has been the subject of several studies in recent years. Positron emission tomography is the most sensitive and specific imaging modality in the detection of metabolic changes, but presents limited spatial resolution. On the other hand, MRI presents a significant spatial resolution, besides evaluating soft tissues signal intensity with excellent contrast resolution. The present iconographic essay is aimed at demonstrating the potential clinical application of PET/MRI coregistration. The studies were performed in a dedicated PET unit with 18F-fluorodeoxyglucose (FDG) as radiopharmaceutical and coregistered with 1.5 T or 3 T brain MRI. The brain images fusion software presents an already well-established accuracy, so a significant synergy between a functional PET study and an excellent MRI anatomical detail is achieved. The most attractive clinical applications of this approach are the following: epileptogenic zone assessment in patients refractory to drug therapy, identification of patients with cognitive impairment at higher risk for progression to dementia and differentiation of dementias and Parkinsonian syndromes.

Keywords: Fluorodeoxyglucose, FDG, Positron emission tomography, PET, Magnetic resonance imaging, Fusion, Clinical neurology

OBJECTIVE: To compare sonographic and magnetic resonance imaging findings in deep endometriosis with emphasis on intestinal involvement. MATERIALS AND METHODS: Eighteen women aged between 23 and 49 years with clinical suspicion and gynecological signs suggestive of deep endometriosis were submitted to ultrasonography and magnetic resonance imaging for correlation between findings. RESULTS: Ultrasonography detected 40 lesions while magnetic resonance imaging detected 53 lesions in the pelvis. A comparative study has not shown any statistically significant intermethod difference in the detection of lesions (respectively p > 0.19 and p > 0.14). In the rectosigmoid junction, magnetic resonance imaging has detected one (5.6%) lesion, while ultrasonography has detected four lesions (22.2%). In the rectum, ultrasonography has detected eight lesions (44.4%), and magnetic resonance imaging has detected seven lesions (38.9%). CONCLUSION: The intermethod agreement has not been good for lesions in the rectosigmoid junction, considering that ultrasonography has detected a higher number of lesions in this region, but a lower number of lesions in the pelvis as compared with magnetic resonance imaging. The global comparative analysis has demonstrated no statistically significant intermethod difference in the detection of lesions. Low cost, good tolerability and high availability make ultrasonography a valuable diagnostic tool in cases of deep endometriosis.

Keywords: Deep endometriosis, Diagnosis, Transvaginal ultrasonography, Magnetic resonance imaging

OBJECTIVE: To identify the students' profile and their motivation to attend the Course of Post-Graduation in Medicine (Radiology) at the School of Medicine of Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil, as well as to quantitative and qualitatively evaluate their scientific production. MATERIALS AND METHODS: A questionnaire comprised of both open and closed questions was sent to 183 post-graduates, and 148 returned with answers. Expectations, professional destiny and scientific production were evaluated. RESULTS: Technical and scientific improvement (39.08%) and docent career progression (26.82%) were the primary motivating factors for students to attend the post-graduation course. The changes resulting from the conclusion of the course were: improvement of technical knowledge (33.33%) and higher confidence in their professional performance (17.83%). This survey has demonstrated that 60.42% of the respondents work in higher education institutions and 39.58% do not, and that 84.93% of the scientific papers about themes of theses/dissertations were published. CONCLUSION: The course has met the essential requirements for researchers and docents education. Also, the survey has demonstrated the necessity of a more effective performance of the program docents besides curricular changes with the introduction of a discipline dedicated to the preparation of scientific papers.

Keywords: Post-graduates, Profile, Post-graduation, Radiology, UFRJ

OBJECTIVE: To demonstrate the relevance of ultrasonography and magnetic resonance imaging findings in the prenatal characterization and prognostic evaluation in cases of congenital diaphragmatic hernia. MATERIALS AND METHODS: Fourteen pregnant women (mean gestational age = 28.7 weeks) who had undergone ultrasonography for suspicion of fetuses with congenital diaphragmatic hernia were assessed by means of magnetic resonance imaging on a 1.5 tesla equipment, following the standard protocol. Two radiologists evaluated the images and the findings were defined by consensus. RESULTS: Twelve fetuses had left diaphragmatic hernia and two, right diaphragmatic hernia. Ultrasonography showed the fetal liver inside the thorax of five fetuses (three with left diaphragmatic hernia, and two with right diaphragmatic hernia) and magnetic resonance imaging in eight fetuses (six with left diaphragmatic hernia, and two with right diaphragmatic hernia). Stomach and small bowel loop herniation was observed in all of the fetuses with left diaphragmatic hernia (n = 12) at both magnetic resonance imaging and ultrasonography. Eight fetuses (seven with left diaphragmatic hernia and one with right diaphragmatic hernia) survived after surgical treatment. CONCLUSION: Ultrasonography and magnetic resonance imaging are complementary imaging methods in the evaluation of congenital diaphragmatic hernia. Magnetic resonance imaging is a helpful diagnostic method complementary to ultrasonography for evaluation of the fetal liver positioning, considering its relevance as a prognostic factor in cases of congenital diaphragmatic hernia.

Keywords: Fetus, Congenital diaphragmatic hernia, Ultrasonography, Magnetic resonance imaging

Endometriosis is characterized by the presence of normal endometrial tissue outside the uterine cavity. In patients with deep pelvic endometriosis, uterosacral ligaments, rectum, rectovaginal septum, vagina or bladder may be involved. Clinical manifestations may be variable, including pelvic pain, dysmenorrhea, dyspareunia, urinary symptoms and infertility. Complete surgical excision is the gold standard for treating this disease, and hence the importance of the preoperative work-up that usually is limited to an evaluation of sonographic and clinical data. Magnetic resonance imaging is of paramount importance in the diagnosis of endometriosis, considering its high accuracy in the identification of lesions intermingled with adhesions, and in the determination of peritoneal lesions extent. The present pictorial review describes the main magnetic resonance imaging findings in deep pelvic endometriosis.

Keywords: Magnetic resonance imaging, Endometriosis, Female pelvis, Infertility

OBJECTIVE: The present study was aimed at correlating ultrasonographic and magnetic resonance imaging findings in patients with fetal sacrococcygeal teratoma. MATERIALS AND METHODS: Three pregnant women between the 30th and 35th weeks of gestation were submitted to fetal magnetic resonance imaging because of previous ultrasonographic findings suggestive of fetal sacrococcygeal teratoma. Subsequently, they were submitted to ultrasonography for correlation of the imaging findings. Tumors size, location, extent and content were evaluated both at magnetic resonance imaging and ultrasonography. RESULTS: Findings regarding tumor location, size and content were similar for both methods. All the lesions were found in the sacrococcygeal region, with a mean size of 6.0 cm x 9.0 cm. As regards the tumors content, two of them were mixed solid-cystic, and one, entirely cystic. Magnetic resonance imaging was superior to ultrasonography in the evaluation of the exact tumor extent, accurately demonstrating pelvic involvement in all of the three cases. CONCLUSION: Fetal magnetic resonance imaging has showed to be a valuable adjunct to obstetric sonography in the evaluation of fetal sacrococcygeal teratoma, because of its higher accuracy in the determination of these tumors extent and content, playing a significant role in the therapeutic planning and increasing the chances of cure for these fetuses.

Keywords: Fetus, Sacrococcygeal teratoma, Ultrasonography, Magnetic resonance imaging

OBJECTIVE: To describe morphological aspects, and radiographically evaluate the segment of the peroneus longus tendon adjacent to the cuboid bone, in cadavers, and reporting the incidence of a fibular ossicle, in some cases with the help of histological analysis. MATERIALS AND METHODS: Fifty tendon segments were evaluated and radiographed for determining the presence or absence of an accessory ossicle inside the tendon. The specimens where such presence was dubious were sectioned and submitted to macroscopic evaluation. In the cases where doubts persisted, the specimens were submitted to hematoxylin-eosin staining for histological analysis. One specimen where the accessory ossicle had been detected was also histologically evaluated for illustration purposes. RESULTS: All the specimens presented a fusiform dilatation of the area under the arc of the cuboid bone. Radiographic images demonstrated 29 specimens without ossification, 13 with ossification and 8 were doubtful. After macroscopic analysis, only one presented ossification, five did not, and two remained dubious, being submitted to histological analysis that demonstrated no ossification. CONCLUSION: All the specimens presented focal thickening of the tendon under the arc of the cuboid bone. However, quantitative analysis of both specimens submitted to histological evaluation demonstrated that the tendon consisted of fibrocartilaginous tissue lined by hyaline cartilage on the surface of contact with the bone. Thus, under the morphological point of view, fibular ossicle was found in 28% of cases, and, under the radiographic point of view, in 26%.

Keywords: Peroneus longus, Os peroneum, Sesamoid

OBJECTIVE: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. MATERIALS AND METHODS: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign) were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Timesignal intensity curves and slope values were calculated. The statistical analysis was performed with the Levene's test, followed by a Student's t-test, besides the Pearson's chi-squared and Fischer's exact tests. RESULTS: Proton magnetic resonance spectroscopy sensitivity, specificity and accuracy were, respectively, 87.5%, 92.3% and 90.9% (p < 0.0001). Statistically significant difference was observed in the slope (%/min) between benign (mean, 27.5%/min) and malignant (mean, 110.9%/min) lesions (p < 0.0001). CONCLUSION: The time-intensity curve and slope values using dynamic-enhanced perfusion magnetic resonance imaging in association with the presence of choline peak demonstrated by single voxel magnetic resonance spectroscopy study are useful in the differentiation between malignant and benign musculoskeletal tumors.

Keywords: Proton magnetic resonance spectroscopy, Perfusion magnetic resonance imaging, Magnetic resonance imaging

OBJECTIVE: To evaluate three cases of cervical lymphangioma with magnetic resonance imaging and correlating with sonographic findings. MATERIALS AND METHODS: Three pregnant women between the 24th and 35th gestational weeks, with sonographic findings suggestive of fetal cystic hygroma, were submitted to magnetic resonance and subsequently to a new ultrasonography for correlation of imaging findings. Tumors size, location, content and extent were evaluated both at magnetic resonance imaging and ultrasonography. RESULTS: Findings regarding tumor location, size and content were similar for both methods. All the lesions were found in the posterior and lateral cervical space. As regards the tumors content, two of the lesions were predominantly cystic, with thin septations, and the other was heterogeneous. Lesions extent and adjacent structures invasion were better characterized by magnetic resonance imaging, with appropriate demonstration of invasion of the pinna in one case and invasion of the superior mediastinum in another. CONCLUSION: Fetal magnetic resonance imaging can be a useful adjuvant to obstetric ultrasonography in cases of lymphangioma because of its higher accuracy in the determination of these tumors extent and adjacent structures invasion, allowing a better postnatal surgical planning.

Keywords: Fetus, Lymphangioma, Cystic hygroma, Ultrasonography, Fetal magnetic resonance imaging

OBJECTIVE: The purpose of this study was to describe the tomographic findings of gastric gastrointestinal stromal tumor. MATERIALS AND METHODS: Fourteen patients with histopathologically and immunohistochemically confirmed gastric gastrointestinal stromal tumors, who had already been submitted to computed tomography scans before the treatment, were evaluated in the period between January 1999 and December 2006. The following tomographic variables were analyzed: lesion topography, size/dimensions, homogeneity, contour, margins, morphology, pattern and intravenous contrast-enhancement intensity, growth pattern, invasion of adjacent organs, presence of ulceration, fistula, calcifications, mesenteric fat infiltration, lymphadenomegaly and presence of distant metastasis. RESULTS: Tumors were found in the body (57.1%) or in the gastric fundus (42.9%), with sizes ranging between 6.0 cm and 23.0 cm (mean, 11.5 cm). Predominantly extraluminal growth was observed in 57.1% of cases and intra/extraluminal in 35.7%. Subtle contrast-enhancement was observed in 50%, moderate in 50%, and heterogeneous in 64.3% of cases. Additionally, central hypodensity was observed in 64.3%, invasion of adjacent organs in 42.9%, and hepatic metastasis in 7.2% of cases. CONCLUSION: In the present study, the majority of tumors were found in the gastric body, with an average size of 11.5 cm, presenting with central hypodensity, heterogeneous contrast-enhancement and predominantly extraluminal growth.

Keywords: Gastrointestinal stromal tumors, Stomach neoplasms, Spiral computed tomography

Objective: The present study was aimed at evaluating the role of diffusion tensor imaging for the assessment of different patterns of white matter involvement in patients with brain tumors and the utility of this technique for differential diagnosis of such neoplasms. Materials and methods: Forty-four patients with brain tumors, including low-grade gliomas, anaplastic astrocytomas, glioblastomas multiforme and metastases, were studied with conventional and diffusion tensor magnetic resonance imaging. White matter tracts around the tumors were characterized as displaced, disrupted, infiltrated and edematous. Results: A significant overlap was observed between patterns of white matter involvement on diffusion tensor images as the displaced pattern was seen in all the types of tumor. Disrupted and infiltrated patterns were found in glioblastomas multiforme and anaplastic astrocytomas. The edematous pattern was found in the cases of metastases. Conclusion: Diffusion tensor imaging patterns of white matter involvement assists in the mapping of tracts adjacent to tumors, providing significant data about tumors extent; however, they cannot distinguish low-grade and high-grade gliomas from metastases.

Keywords: Diffusion tensor imaging; White matter; Brain tumors.

Spondylodiscitis represents 2%-4% of all bone infections cases. The correct diagnosis and appropriate treatment can prevent complications such as vertebral collapse and spinal cord compression, avoiding surgical procedures. The diagnosis is based on characteristic clinical and radiographic findings and confirmed by blood culture and biopsy of the disc or the vertebra. The present study was developed with Clementino Fraga Filho University Hospital patients with histopathologically and microbiologically confirmed diagnosis of spondylodiscitis, submitted to magnetic resonance imaging of the affected regions. In most cases, pyogenic spondylodiscitis affects the lumbar spine. The following findings are suggestive of the diagnosis: segmental involvement; ill-defined abscesses; early intervertebral disc involvement; homogeneous vertebral bodies and intervertebral discs involvement. Tuberculous spondylodiscitis affects preferentially the thoracic spine. Most suggestive signs include: presence of well-defined and thin-walled abscess; multisegmental, subligamentous involvement; heterogeneous involvement of vertebral bodies; and relative sparing of intervertebral discs. The present pictorial essay is aimed at showing the main magnetic resonance imaging findings of pyogenic and tuberculous discitis.

Keywords: Magnetic resonance imaging; Discitis; Intervertebral disc; Spinal tuberculosis.

Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI). Those functional techniques are related to biological properties of the tumor, so that DWI correlates to cellularity and Gleason scores, DCE correlates to angiogenesis, and MRSI correlates to cell membrane turnover. The combined use of those techniques enhances the diagnostic confidence and allows for better characterization of PCa. The present article reviews and illustrates the technical aspects and clinical applications of each component of mpMR imaging, in a practical approach from the urological standpoint.

Keywords: Prostate cancer; Magnetic resonance imaging; Diffusion-weighted imaging; Dynamic contrast enhancement.

OBJECTIVE: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. MATERIALS AND METHODS: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. RESULTS: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. CONCLUSION: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models.

Keywords: Fetus; Fetal medicine; Three-dimensional technique; Ultrasound; Magnetic resonance imaging; Computed tomography.

Although infection with the Zika virus was first recognized in 1942, it received little attention until 2007, when a true pandemic spread throughout Africa, Asia, and the Americas. Since then, numerous forms of central nervous system involvement have been described, mainly malformations related to congenital infection. Although the neuroimaging findings in congenital Zika syndrome are not pathognomonic, many are quite suggestive of the diagnosis, and radiologists should be prepared to interpret such findings accordingly. The objective of this article is to review the computed tomography and magnetic resonance imaging findings in congenital Zika syndrome.

Keywords: Magnetic resonance imaging; Computed tomography; Zika virus; Congenital Zika syndrome; Congenital infection.