Prevalence of obstructive sleep apnea in patients with prolactinoma before and after treatment with dopamine agonists.

OBJECTIVES: Obesity is the main risk factor for the development of obstructive sleep apnea (OSA). Hyperprolactinemia has also been related to obesity. To determine the OSA prevalence in patients with prolactinoma before and after dopamine agonist (DA) and to evaluate the correlation between the apnea-hypopnea index (AHI) and prolactin levels, body mass index (BMI), waist circumference (WC), visceral fat volume (VFV), subcutaneous fat volume, and other metabolic parameters. METHODS: Thirty-five patients with prolactinoma at baseline and twenty-one who completed the 6-month DA treatment were submitted to clinical/laboratorial evaluations, polysomnography and abdominal imaging. RESULTS: Before treatment, the prevalence of obesity/overweight and OSA were, respectively, 68.5 and 34.2 %. We found a positive correlation between AHI and weight (r = 0.57; p < 0.001), BMI (r = 0.56; p < 0.001), WC (r = 0.61; p < 0.001), VFV (r = 0.55; p = 0.002), insulin levels (r = 0.57; p < 0.001), and HOMA-IR index (r = 0.57; p < 0.001); and a negative correlation between AHI and HDL-cholesterol (r = -0.47; p = 0.005). After multivariate analysis, VFV and insulin levels were the most important predictors for AHI (p = 0.001 and p = 0.02, respectively). After DA, the obesity/overweight and OSA prevalence did not change. CONCLUSIONS: The OSA prevalence in patients with prolactinoma is similar to the obese subjects and did not change after treatment. Higher BMI and visceral obesity, but not prolactin levels, seem to be the major factor involved in the occurrence of OSA in these patients.

Congenital chest malformations: a multimodality approach with emphasis on fetal MR imaging.

Congenital chest malformations can range from small and asymptomatic entities to large space-occupying masses that require immediate surgical treatment. They may affect the foregut, pulmonary airway, and vasculature. Hybrid conditions are commonly seen, with interrelated chest malformations having various radiologic and pathologic features. An understanding of the in utero complications associated with fetal chest masses is essential for appropriate monitoring during pregnancy, treatment recommendations, and delivery management. Technologic advances have greatly improved the diagnosis of fetal anomalies. Congenital chest malformations are usually evaluated in the prenatal period with fetal sonography, but fetal magnetic resonance (MR) imaging is a well-established modality that is used as an adjunct technique in difficult diagnostic situations. MR imaging can provide excellent tissue contrast with more accurate analysis of the fetal anatomy and superior differentiation between the abnormalitites and adjacent structures, thereby allowing early planning of prenatal management.

Assessment of breast lesions with diffusion-weighted MRI: comparing the use of different b values.

OBJECTIVE: Our purpose was to study the utility of diffusion-weighted MRI in differentiating benign from malignant breast lesions by assessing the best b values. SUBJECTS AND METHODS: Forty-five women (mean age, 46.1 years) with 52 focal mass breast lesions underwent diffusion-weighted imaging with different b values. The apparent diffusion coefficient (ADC) value of each lesion was calculated from the ADC maps done using five b values (0, 250, 500, 750, and 1,000 s/mm(2)) and using b values of 0 s/mm(2) with each other b value separately (0 and 250 s/mm(2), 0 and 500 s/mm(2), 0 and 750 s/mm(2), 0 and 1,000 s/mm(2)). The mean ADC values were correlated with imaging findings and histopathologic diagnoses. The cutoff ADC value, sensitivity, and specificity of diffusion-weighted imaging to differentiate benign and malignant lesions were calculated in all b value combinations. A p value of < 0.05 was considered statistically significant. RESULTS: The mean ADC value was significantly lower for malignant lesions compared to benign lesions (p < 0.0001) in all b value combinations. No statistical difference was seen between the ADC obtained from different b value combinations (p = 0.2581) in the differentiation between benign and malignant lesions. The ADC calculated from b 0 and 750 s/mm(2) was slightly better than the other b value combinations, showing a sensitivity of 92.3% and a specificity of 96.2%. CONCLUSION: Diffusion-weighted imaging is a potential resource as a coadjutant of MRI in the differentiation between benign and malignant lesions. Such imaging can be performed without a significant increase in examination time, especially because it can be done with lower b values.

Utility of [(18)F] fluoro-2-deoxy-D: -glucose positron emission tomography in the localization of ectopic ACTH-secreting tumors.

Ectopically ACTH producing tumors may be difficult to localize by conventional radiology and functional imaging may be helpful. Case 1: 31-year-old man was diagnosed with ectopic ACTH-dependent Cushing's syndrome (ECS). Thorax CT revealed a 1.3 cm nodular opacity in upper left lobe, suggestive of residual lesion. [(18)F] fluoro-2-deoxy-D: -glucose ([(18)F] FDG) positron emission tomography ([(18)F] FDG PET) scan revealed mild glycolytic metabolic activity. Pathological examination confirmed an ACTH-positive carcinoid tumor. Case 2: 53-year-old woman presented with very rapid onset ECS. Pituitary MRI was normal. Thorax CT revealed no tumoral lesion. Abdominal and pelvic MRI showed images suggestive of hepatic and iliac, femoral and lumbar secondary implants. [(18)F] FDG PET scan revealed intense uptake in uterus, especially cervix, suggesting this to be the primary tumor site. These cases illustrate the role of [(18)F] FDG PET in the investigation of an ECS where conventional imaging studies were not elucidative in the search for a responsible tumor.

Potential role of diffusion tensor MRI in the differential diagnosis of mild cognitive impairment and Alzheimer's disease.

OBJECTIVE: The purpose of this study was to evaluate the fractional anisotropy values of several white matter tracts with the aim of differentiating a healthy population from persons with mild cognitive impairment or Alzheimer's disease. SUBJECTS AND METHODS: Seventy-nine patients with memory impairment and 16 volunteer controls participated in the study. MRI was performed with a 1.5-T system. Conventional MR images and diffusion tensor images were obtained for all participants. The diffusion tensor imaging data were postprocessed, and low b-value, fractional anisotropy, and fractional anisotropy color-coded maps were calculated. With the three maps as an anatomic reference, fractional anisotropy was measured for hippocampal formations, superior longitudinal fascicles, posterior cingulate gyri, and the splenium of the corpus callosum. Kruskal-Wallis and Steel-type multiple-comparison nonparametric tests were performed for the statistical analysis. RESULTS: The fractional anisotropy values for the splenium of the corpus callosum, bilateral posterior cingulate gyri, and bilateral superior longitudinal fascicles of patients with mild cognitive impairment and those with probable Alzheimer's disease were significantly lower than the values of controls. No differences were found in hippocampal formations in any group. No significant difference was found in fractional anisotropy values in comparisons of mild cognitive impairment versus possible Alzheimer's disease and probable Alzheimer's disease or comparisons of probable Alzheimer's disease and possible Alzheimer's disease. CONCLUSION: Diffusion tensor imaging is a promising technique for the evaluation of patients with probable mild cognitive impairment. Early detection of the disease expands the treatment options, increasing the likelihood of a good clinical response and enhancing the quality of life of patients and their relatives. Further studies with larger populations are needed to confirm the role of diffusion tensor imaging in the evaluation of memory impairment.

Diffusion tensor MR imaging evaluation of the corpus callosum of patients with multiple sclerosis.

OBJECTIVE: To evaluate the fractional anisotropy (FA) values of the normal-appearing white matter of the corpus callosum (CC) in patients with relapsing-remitting multiple sclerosis (MS). METHOD: Fifty-seven patients with diagnosis of relapsing-remitting MS and 47 age- and gender-matched controls were studied. A conventional MR imaging protocol and a DTI sequence were performed. One neuroradiologist placed the regions of interest (ROIs) in the FA maps in five different portions of the normal-appearing CC (rostrum, genu, anterior and posterior portion of the body and splenium) in all cases. The statistical analysis was performed with the Mann-Whitney U test and p<0.05 was considered statistically significant. RESULTS: The FA values were lower in the MS patients compared with the controls (p<0.05) in the following CC regions: rostrum (0.720 vs 0.819), anterior body (0.698 vs 0.752), posterior body (0.711 vs 0.759) and splenium (0.720 vs 0.880). CONCLUSION: In this series, there was a robust decrease in the FA in all regions of the normal-appearing CC, being significant in the rostrum, body and splenium. This finding suggests that there is a subtle and diffuse abnormality in the CC, which could be probably related to myelin content loss, axonal damage and gliosis.

Evaluation of white matter in patients with multiple sclerosis through diffusion tensor magnetic resonance imaging.

OBJECTIVE: To study the white matter of patients with multiple sclerosis (MS) with diffusion tensor magnetic resonance (MR) imaging (DTI). METHOD: Forty patients with clinical-laboratorial diagnosis of relapsing-remitting MS and 40 age- and sex-matched controls, who underwent conventional and functional (DTI) MR imaging, were included in the study. The DTI sequences resulted in maps of fractional anisotropy (FA) and regions of interest were placed on the plaques, peri-plaque regions, normal-appearing white matter (NAWM) around the plaques, contralateral normal white matter (CNWM) and normal white matter of the controls (WMC). The FA values were compared and the statistical treatment was performed with the Mann-Whitney U test. RESULTS: The mean FA in plaques was 0.268, in peri-plaque regions 0.365, in NAWM 0.509, in CNWM 0.552 and in WMC 0.573. Statistical significant differences in FA values were observed in plaques, peri-plaque regions and in NAWM around the plaques when compared to the white matter in the control group. There was no significant difference between the FA values of the CNWM of patients with MS and normal white matter of controls. CONCLUSION: Patients with MS show difference in the FA values of the plaques, peri-plaques and NAWM around the plaques when compared to the normal white matter of controls. As a result, DTI may be considered more efficient than conventional MR imaging for the study of patients with MS.

Chronic inflammatory demyelinating polyradiculoneuropathy: two cases with cervical spinal cord compression.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a peripheral nerve disorder probably due to an immunological disturb. It evolves either in a steadily progressive or in a relapsing and fluctuating course. Weakness is mainly in the lower limbs proximally and distally. The electromyography is demyelinating. The cerebral spinal fluid protein is most of times elevated. Sometimes enlarged nerves are found. There are few cases described with spinal cord compression due to hypertrophic spinal nerve roots. Two patients (females, 66 and 67 years old) with diagnosis of a long standing CIDP are described. In the first one, the evolution was characterized by remission and relapsing course. The second patient had a chronic and progressive course. These patients presented after a long evolution a cervical spinal cord compression syndrome due to hypertrophic cervical roots. Neurologists must be aware of the possibility of development of spinal cord compression by enlarged spinal roots in patients with a long standing CIDP.

[Pseudotumor cerebri secondary to dural sinus thrombosis: pediatric case report]. / Pseudotumor cerebral secundário a trombose venosa dural: relato de caso pediátrico.

Pseudotumor cerebri is a relatively common neurologic syndrome in adolescence. In most cases, etiology is idiopathic, but it may have serious complications, such as blindness, that are related to increased intracranial pressure. The aim of this article is to emphasize the differential diagnosis of pseudotumor cerebri, with special attention to treatable etiologies. We report a case of an 12 year-old adolescent who presented with diplopia and headache 9 days after right-sided otitis media and mastoiditis. Head computerized tomography was normal, but brain magnetic resonance imaging demonstrated thrombosis of ipsilateral transverse and sigmoid sinuses, which responded promptly to early anticoagulation. The conclusion is that magnetic resonance imaging is essential for patients with a clinical diagnosis of pseudotumor cerebri in order to exclude treatable causes, such as dural sinus thrombosis.

Functional and motor response to low dose olanzapine in Huntington's disease: case report.

Previous reports on the use of olanzapine in Huntington's disease (HD) used doses ranging from 10-30 mg. We report a case of HD with marked delusions and behavioral impairment assessed by the Unified Huntington's Disease Rating Scale at baseline and four months later treated with a low dose of olanzapine. The patient improved in motor, psychiatric and activity of daily living symptoms after four months of treatment. The response to a low dose of olanzapine in HD may be an indicator of efficacy in similar cases. Further randomized controlled trials can properly assess these findings.

Magnetic resonance of the liver with hepato-specific contrast: initial clinical experience in Brazil.

The authors report the initial clinical experience of gadoxetic acid as a liver-specific magnetic resonance (MR) imaging contrast mediumin a private clinic in Brasil. This substance, which was recently approved for clinical use in the country, shows specific uptake by the hepatocytes, reaching a concentration peak around 10-20 minutes post-injection. Among the main indications for the use of this contrast medium in MR examinations are: diagnosis of hepatocellular carcinoma, detection and treatment planning of liver metastases, and the differentiation between focal nodular hyperplasia and hepatocellular adenoma.

The cervical spinal cord in neuromyelitis optica patients: a comparative study with multiple sclerosis using diffusion tensor imaging.

INTRODUCTION: This study aims to evaluate "in vivo" the integrity of the normal-appearing spinal cord in patients with neuromyelitis optica (NMO), using diffusion tensor MR imaging, comparing to controls and patients with multiple sclerosis (MS). MATERIALS AND METHODS: We studied 8 patients with NMO and 17 without any neurologic disorder. Also, 32 MS patients were selected. Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD) were calculated within regions of interest at C2 and C7 levels in the four columns of the spinal cord. RESULTS: At C2, the FA value was decreased in NMO patients compared to MS and controls in the anterior column. Also in this column, RD value showed increase in NMO compared to MS and to controls. The FA value of the posterior column was decreased in NMO in comparison to controls. At C7, AD value was higher in NMO than in MS in the right column. At the same column, MD values were increased in NMO compared to MS and to controls. CONCLUSIONS: There is extensive NASC damage in NMO patients, including peripheral areas of the cervical spinal cord, affecting the white matter, mainly caused by demyelination. This suggests a new spinal cord lesion pattern in NMO in comparison to MS.

Diffusion MR imaging in central nervous system.

Diffusion-weighted imaging has been used extensively in clinical practice for the early diagnosis of central nervous system conditions that restrict the diffusion of water molecules because it provides information about tumor cellularity or abscesses containing viscous fluid. DTI can detect brain lesions before any conventional imaging. Even though the role of these modalities is well defined for many neurologic lesions that affect the brain, its clinical application in spinal cord diseases is increasing. This article discusses the several central nervous system conditions that may be diagnosed with diffusion imaging.

PET/CT and vascular disease: current concepts.

Since its introduction in 2001, positron emission tomography associated to computed tomography (PET/CT) has been established as a standard tool in cancer evaluation. Being a multimodality imaging method, it combines in a single session the sensitivity granted by PET for detection of molecular targets within the picomolar range, with an underlying submilimetric resolution inherent to CT, that can precisely localize the PET findings. In this last decade, there have been new insights regarding the pathophysiology of atherosclerosis, particularly about plaque rupture and vascular remodeling. This has increased the interest for research on PET/CT in vascular diseases as a potential new diagnostic tool, since some PET molecular targets could identify diseases before the manifestation of gross anatomic features. In this review, we will describe the current applications of PET/CT in vascular diseases, emphasizing its usefulness in the settings of vasculitis, aneurysms, vascular graft infection, aortic dissection, and atherosclerosis/plaque vulnerability. Although not being properly peripheral vascular conditions, ischemic cardiovascular disease and cerebrovascular disease will be briefly addressed as well, due to their widespread prevalence and importance.

Primary mediastinal liposarcoma - computed tomography and pathological findings: a case report.

Liposarcomas are the most common soft tissue sarcoma of adults, and primary mediastinal liposarcomas are rare. We present a case of a 50-year-old man with primary mediastinal liposarcoma without any invasion into the surrounding structures, such as the esophagus, trachea, or left atrium of the heart. Following surgical removal of the liposarcoma, the patient has had no recurrence after one year. Surgical removal is the treatment of choice for a mediastinal liposarcoma; however, careful long-term follow-up is necessary because the recurrence rate is very high.

Evaluation of atherosclerosis in renal transplanted patients by non-invasive methods.

BACKGROUND: Endothelial dysfunction can be considered an early atherogenic event. OBJECTIVE: To assess atherosclerosis in renal transplanted patients through the coronary calcium score, carotid duplex scan and brachial reactivity through ultrasonography. METHODS: We assessed 30 renal transplanted male patients with stable renal function, with a mean age of 41.3 years. RESULTS: The detection of the atherosclerotic load in this population was very significant when the brachial reactivity technique was used (86.7%); it was less frequent when based on the presence of carotid plaque (33.3%) or the coronary calcium score (20%). The carotid plaque was considered when the thickness was > 12 mm. The coronary calcium score was abnormal when > 80 according to the Agatston scale, being observed in a low percentage of patients (21.7%), possibly due to the fact that the tomography is not the ideal method to detect atherosclerosis in renal patients, as it does not differentiates intimal calcifications of the medial layer. The adequate clinical control, the low age range and the factors related to the time of pre-transplant dialysis or the anti-inflammatory effect of the post-transplant drugs can delay the onset of the calcifications. CONCLUSION: The evaluation of the atherosclerotic load through the carotid duplex scan (33,3%) and the coronary calcium score (20%) was not frequent; there was no correlation with the high rate of endothelial dysfunction detection observed with the brachial reactivity assessment (86.7%).

Diffusion tensor imaging findings in school-aged autistic children.

OBJECTIVE: To analyze and compare cerebral white matter tracts through diffusion tensor imaging in autistic and normal children. METHODS: This is a case-control study on a sample of eight male, right-handed children diagnosed with autism according to Diagnostic and Statistical Manual of Mental Disorders-4th Edition criteria, and eight healthy age- and sex-matched controls. Imaging studies were performed on a 1.5-T scanner (Symphony Maestro Class, Siemens, Erlangen, Germany). Fractional anisotropy was calculated for the frontopontine and corticospinal tracts, frontal subcortical white matter, anterior cingulate, corpus callosum, striatum, internal capsule, optic radiation, superior and inferior longitudinal fascicles, and cerebellum. Analysis of significance was based on analysis of variance test for the mean fractional anisotropy values. RESULTS: Median age of cases was 9.53 +/- 1.83 years, and of controls, 9.57 +/- 1.36 years. Diffusion tensor imaging findings included significant reduction of fractional anisotropy in the anterior corpus callosum (P= .008), right corticospinal tract (P= .044), posterior limb of right and left internal capsules (P= .003 and .049, respectively), left superior cerebellar peduncle (P= .031), and right and left middle cerebellar peduncles (P= .043 and .039, respectively) in autistic children. CONCLUSIONS: The diffusion tensor imaging findings in children with autistic disorder suggest impairment of white matter microstructure, possibly associated with reduced connectivity in corpus callosum, internal capsule, and superior and middle cerebellar peduncles.

Proton magnetic resonance spectroscopy in children with fetal alcohol spectrum disorders.

OBJECTIVE: To analyze the metabolic constitution of brain areas through proton magnetic resonance spectroscopy in children affected with fetal alcohol spectrum disorder compared with normal children. METHOD: The sample of this case-control study included eight boys with epidemiologic history of in utero exposure to alcohol (median age 13.6+/-3.8 years) who were diagnosed with fetal alcohol spectrum disorder, and eight controls (median age 12.1+/-3,4 years). An 8 cm(3) single voxel approach was used, with echo time 30 ms, repetition time 1500 ms, and 128 acquisitions in a 1.5T scanner, and four brain areas were analyzed: anterior cingulate, left frontal lobe, left striatum, and left cerebellar hemisphere. Peaks and ratios of metabolites N-acetylaspartate, choline, creatine, and myo-inositol were measured. RESULTS: Children with fetal alcohol spectrum disorder showed a decrease in choline/creatine ratio (p=0.020) in left striatum and an increase in myo-inositol/creatine ratio (p=0.048) in left cerebellum compared with controls. There was no statistically significant difference in all peaks and ratios from the anterior cingulate and frontal lobe between the two groups. CONCLUSION: This study found evidence that the left striatum and left cerebellum are affected by intrauterine exposure to alcohol. Additional studies with larger samples are necessary to expand our knowledge of the effects of fetal exposure to alcohol.

Ressonância magnética do fígado com contraste hepato-específico: experiência clínica inicial no Brasil / Magnetic resonance of the liver with hepato-specific contraste: initial clinical experience in Brazil

Os autores relatam a experiência clínica inicial em um serviço privado no Brasil do uso do ácido gadoxético como meio de contraste hepato-específico em exames de ressonância magnética (RM). Esta substância, recentemente liberada para uso comercial no país, pode ser especificamente captada pelos hepatócitos, atingindo um pico de concentração em cerca de 10-20 minutos após a administração endovenosa. Dentre as principais indicações para seu uso em exames de RM, figuram: diagnóstico de carcinoma hepatocelular, detecção e planejamento terapêutico de metástases hepáticas, e a diferenciação entre hiperplasia nodular focal e adenoma hepatocelular.

The authors report the initial clinical experience of gadoxetic acid as a liver-specific magnetic resonance (MR) imaging contrast mediumin a private clinic in Brasil. This substance, which was recently approved for clinical use in the country, shows specific uptake by the hepatocytes, reaching a concentration peak around 10-20 minutes post-injection. Among the main indications for the use of this contrast medium in MR examinations are: diagnosis of hepatocellular carcinoma, detection and treatment planning of liver metastases, and the differentiation between focal nodular hyperplasia and hepatocellular adenoma.

Proton magnetic resonance spectroscopy in school-aged autistic children.

PURPOSE: This study aims to assess cerebral metabolites in school-aged autistic patients through proton magnetic resonance spectroscopy. METHODS: This case-control study included 10 right-handed male children (median age, 9.53 years +/- 1.80) with autism according to DSM-IV criteria, and 10 healthy age- and sex-matched healthy controls (median age, 8.52 years +/- 1.42). Imaging was performed on a 1.5-T scanner utilizing a single voxel point-resolved spectroscopy (PRESS) technique (TR = 1,500 ms, TE = 30 ms). Four cerebral areas were evaluated: bilateral anterior cingulate, left striatum, left cerebellar hemisphere, and left frontal lobe. Peak areas and ratios to creatine (Cr) of N-acetylaspartate (NAA), choline (Cho), and myo-inositol (mI) were analyzed. RESULTS: Compared with controls, autistic children showed a significant increase in mI (P= .021) and Cho (P= .042) peak areas in anterior cingulate and in mI/Cr ratio in anterior cingulate (P= .037) and left striatum (P= .035). The remaining metabolites and ratios were not significantly different between the 2 groups. CONCLUSIONS: This study found a statistically significant increase in myo-inositol and choline in anterior cingulate and left striatum of autistic children compared with controls. In contrast to previous studies, NAA peak area and NAA/Cr and NAA/Cho ratios had no statistically significant decrease in any of the 4 brain regions.