OBJECTIVE: To determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. MATERIALS AND METHODS: Retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. RESULTS: Main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. CONCLUSION: Cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates.

Keywords: Magnetic resonance, Cerebral venous thrombosis, Cerebral infarct, Intracranial hemorrhage

OBJECTIVE: To establish a correlation between clinical features in a group of children with tomographic diagnosis of schizencephaly and clefts extent and localization. MATERIALS AND METHODS: Retrospective study of dossiers from the archives of Neurology and Medical Genetics Services at Instituto Fernandes Figueira/Fiocruz and Hospital Municipal Jesus, Rio de Janeiro, RJ, Brazil, in the period between 2000 and 2003. The study included 16 patients, nine female and seven male, with tomographic diagnosis of schizencephaly investigated for clinical findings, psychomotor development, motor/cognitive deficits and epilepsy. RESULTS: Predominance of bilateral clefts in 10:16 patients, open-lip schizencephaly type in 23:27 patients, and small lips in 11:27 patients. As regards anomalies associated with schizencephaly, pellucid septum absence was the most frequent one (10:16 patients). As regards clinical findings, 15 patients presented with developmental delay and motor deficit, six patients with cognitive deficit and ten with epilepsy. In three patients, we observed discordant clinical findings and cleft sizes, although the clefts were small, the clinical features severity was high because of other cerebral anomalies. CONCLUSION: The clinical features of schizencephaly are related to the size of the clefts, regardless laterality, presenting higher severity when associated with other cerebral anomalies.

Keywords: Schizencephaly, Computed tomography, Clinical findings

OBJECTIVE: The aim of this study was to evaluate the main findings of computed tomography in patients presenting acute leukemia complicated by angioinvasive aspergillosis. MATERIALS AND METHODS: Computed tomography images of 19 patients were retrospectively studied for the presence of consolidations, nodules and masses, with or without presentation of halo sign, cavitation and air crescent sign. RESULTS: Consolidation was the most frequent finding, occurring in 12 of the 19 cases, most of them presenting the halo sign; cavitation was found in 5 of 12 cases, one of them with air crescent sign. Nodules and masses occurred respectively in six and four cases, most of them with halo sign. Cavitation was found in only one case of mass. Other findings observed were: crazy-paving pattern (two cases), patchy areas of ground-glass attenuation opacity (three cases) and pleural involvement (seven cases) under the form of effusion or thickening. CONCLUSION: Areas of consolidation, mass or nodule, even a solitary one, presenting halo sign on CT images evaluated in an appropriate clinical context are highly suggestive of angioinvasive aspergillosis.

Keywords: Angioinvasive pulmonary aspergillosis, Acute leukemia, Computed tomography

OBJECTIVE: To compare ventricular systolic parameters on segmented and real-time steady-state free precession cine-MRI sequences and ECG-gated MRI in patients presenting or not with cardiac arrhythmias. MATERIALS AND METHODS: Ejection fraction and end-diastolic/end-systolic volumes have been compared in 31 patients, 11 presenting with cardiac arrhythmias, and 20 with regular sinus rhythm, using ECG-gated segmented and real-time sequences. The statistical analysis was performed using Pearson's correlation and Bland-Altman agreement plot, with p < 0.01. RESULTS: Real-time acquisitions demonstrated endocardial borders blurring effects, but both sequences presented a clear, positive correlation: ejection fraction r = 0.94; end-diastolic volume r = 0.93 and end-systolic volume r = 0.98. The assessment of 11 patients with arrhythmias has not demonstrated a statistically significant difference, despite the lower blood pool-myocardial contrast ratio. CONCLUSION: Real-time sequences may be utilized for cardiac function assessment, regardless the patient's cardiac rhythm.

Keywords: Cine-RMI, Ventricular function, Steady-state free precession, Real-time, ECG-gated MRI

OBJECTIVE: To evaluate the interobserver agreement on non-contrast computed tomography interpretation by a group of experienced abdominal radiologists, for the study of urolithiasis in patients presenting acute flank pain. MATERIALS AND METHODS: Prospective study of 52 patients submitted to non-contrast enhanced helical computed tomography. The images were subsequently analyzed by three independent observers, with the interobserver agreement assessed by means of the kappa (kappa) statistical method. The following parameters were analyzed: a) presence, localization and measurement of ureteral calculi; b) intrarenal calyceal system dilatation; c) perirenal fat heterogeneity; d) ureteral dilatation; e) ureteral wall edema (halo sign). RESULTS: Ureteral calculi were found in 40 of 52 patients (77%). The interobserver agreement was almost perfect as regards identification of ureteral calculi (kappa = 0.89) and ureteral dilatation (kappa = 0.87), substantial for calyceal system dilatation (kappa = 0.77), and moderate for perirenal fat heterogeneity (kappa = 0.55) and ureteral wall edema (kappa = 0.56). CONCLUSION: Non-contrast-enhanced abdominal computed tomography presents high reproducibility in the evaluation of urolithiasis and secondary signs of the calyceal system obstruction.

Keywords: Lithiasis, Ureteral calculi, Flank pain, Computed tomography

OBJECTIVE: To systematize the assessment of vestibular aqueduct by high-resolution computed tomography (HRCT) in patients with unilateral Ménière's disease as compared with a control group. MATERIALS AND METHODS: We have selected 20 patients with unilateral Ménière's disease, according to the guidelines proposed by the American Academy of Otolaryngology - Head and Neck Surgery. The control group consisted of ten individuals with normal audiometric tests. Overall, we have studied 60 ears, equally divided into three groups: group I - Ménière's disease, affected ear; group II - Ménière's disease, non-affected ear; group III - control. All the individuals have undergone temporal bones HRCT. Images were blindly reviewed, trying to evaluate the visibility of the descendent portion of the ventricular aqueduct. Afterwards data were correlated with their respective groups. RESULTS: We have identified the vestibular aqueduct in 95% of ears in group I, 90% in group II, and 100% in group III. CONCLUSION: It is possible to perform a systematic evaluation of the vestibular aqueduct by axial HRCT, using the same radiological technique, anatomical knowledge and sequential images of inner ear structures. With this systematic approach we have obtained a high rate of vestibular aqueduct visualization, with no statistically significant difference between the groups.

Keywords: Vestibular aqueduct, Temporal bone, Tomography, Helicoidal computed tomography, Ménière's disease

OBJECTIVE: The aim of this study is the optimization of mammographic images with a considerable radiation dose reduction. MATERIALS AND METHODS: In the present study the X-ray beam was calibrated for each tension (kVp), aiming at determining the best combination between kVp and mAs, resulting in optical densities of about 1.0 above the base-plus-fog density. RESULTS: This study will bring into question the methods for X-ray beam calibration, the choice of the best image by means of visual grading analysis, comparisons between doses and tube load (kVp × mAs) delivered by the techniques described in this study and by those adopted in the clinical routine at Service of Diagnostic Imaging of Faculdade de Medicina de Botucatu Clinics Hospital, Botucatu, SP, Brazil. Excellent breast radiographic images have been obtained with doses and tube loads reduction of respectively 36.8% and 46.2% in comparison to those employed in our institutions' clinical routine. CONCLUSION: This study is a contribution to the optimization of the risk-benefit ratio for patients and cost-benefit ratio for the institution.

Keywords: Mammography, Homogeneous phantom, Quality control, Dose reduction

OBJECTIVE: In treatment techniques such as dynamic arc, the manual verification of treatment planning system calculations is very difficult. In these cases, the use of computational tools is useful and becomes an essential component of the quality assurance program. MATERIALS AND METHODS: A worksheet-based software has been created to perform an independent dose or monitor unit calculation in treatments applying the dynamic arc technique delivered with micromultileaf collimator. The dose values calculated per arc and per complete treatment, are compared with values obtained from BrainScan v5.3 treatment planning system. The software has been tested with 229 dynamic arc fields representing 42 skull treatments. From these 229 fields, 109 have been calculated in 3D reconstruction of patients CT images, 109 in reconstruction of polymethylmetacrylate phantom images, and 21 in reconstruction of images from a water equivalent phantom. RESULTS: The mean difference of total doses found in the 42 treatments (composites of one or more dynamic arcs), between the verification software and the treatment planning system, was of +1.73% with a 0.76% standard deviation. The maximum difference was 3.32% and the minimum -0.20%. When the 229 dynamic arcs were tested one by one, the average difference found was 1.61% with a 1.04% standard deviation. Maximum and minimum differences were, respectively 4.01% and -2.04%. As a result of the test, in 80.35% the doses calculated have presented a ± 2.5% difference in relation to the doses generated by the planning system. CONCLUSION: The software presented in this study is recommended for checking point dose included in treatment plans as an integral part of the process of quality assurance in radiotherapy and stereotactic radiosurgery when the dynamic arc technique is utilized in treatment with micromultileaf collimator, where a manual calculation is very difficult or even impracticable due the technique complexity.

Keywords: Radiotherapy, Stereotactic radiosurgery, Linac, Quality assurance in radiotherapy, Monitor unit calculation, Micromultileaf collimator

The authors review the literature about intraoperative ultrasonography for evaluation of pancreatic insulinomas. Results of intraoperative ultrasound, preoperative ultrasound and computed tomography are discussed, as well as results of inspection and palpation of the pancreas during surgery, reported in the literature.

Keywords: Insulinoma, Ultrasonography, Intraoperative ultrasonography

The aim of this study is to evaluate the sinonasal complex to identify the main findings and to determine the diseases in this area. An accurate analysis of the local extent and tumoral dissemination through computed tomography and magnetic resonance imaging plays a significant role in the therapeutic planning, also affecting the prognosis.

Keywords: Nasal sinuses, Computed tomography, Magnetic resonance imaging

Although congenital heart defect is the most frequent anomaly in newborns, its antenatal detection rate through conventional ultrasound remains low. 3D and 4D ultrasound technology was developed early in the nineties, bringing great benefits in obstetrics, especially in cases of dubious diagnosis at 2D ultrasound. The spatio-temporal image correlation (STIC) is a significant development in the field of 4D ultrasound. A software coupled with a Voluson 730 Expert equipment allows a volumetric acquisition of the fetal heart and its vascular connections. Volumetric analyses are performed in multiplanar and surface rendering modes or, alternatively in association with color Doppler. Major advantages are fast images acquisition and the possibility of a later analysis by fetal echocardiography specialists. Differently from 2D ultrasound, this technique may be applied for evaluating any congenital cardiopathy because of the increased number of frames acquired from a specific anatomical region. Main disadvantage is related to the necessity of fetal immobility. The higher diffusion of this method may improve prenatal detection of heart malformations since volumes data captured by a sonographer may be sent through the Internet for analysis by fetal echocardiography specialists.

Keywords: Congenital heart defect, Prenatal diagnosis, STIC

Report on a rare case of infestation by cysticercosis involving the cerebral subarachnoid space and the epidural space in the cervical and thoracic regions of a 59-year old female patient who presented nausea, signs of cerebelar ataxia and gradual loss of the sensibility in both legs. The diagnosis was based on magnetic resonance imaging of brain and cervical-thoracic spine demonstrating the presence of cysts in the subarachnoid spaces. An enzyme-linked immunosorbent assay (ELISA) performed on cerebrospinal fluid resulted positive and demonstrated a protein level of 420 mg/dl indicating the disease activity. Parasites were surgically removed for the necessity of thoracic spinal cord decompression. Based on findings of literature review, brief comments were made on the pathogenesis of the intradural-extramedullary spinal cysticercosis cystic form, magnetic resonance imaging findings and treatment.

Keywords: Cysticercosis, Brain, Spine, Magnetic resonance imaging