Postmortem chest computed tomography in COVID-19: A minimally invasive autopsy method.

Objectives: Performing autopsies in a pandemic scenario is challenging, as the need to understand pathophysiology must be balanced with the contamination risk. A minimally invasive autopsy might be a solution. We present a model that combines radiology and pathology to evaluate postmortem CT lung findings and their correlation with histopathology. Methods: Twenty-nine patients with fatal COVID-19 underwent postmortem chest CT, and multiple lung tissue samples were collected. The chest CT scans were analyzed and quantified according to lung involvement in five categories: normal, ground-glass opacities, crazy-paving, small consolidations, and large or lobar consolidations. The lung tissue samples were examined and quantified in three categories: normal lung, exudative diffuse alveolar damage (DAD), and fibroproliferative DAD. A linear index was used to estimate the global severity of involvement by CT and histopathological analysis. Results: There was a positive correlation between patient mean CT and histopathological severity score indexes - Pearson correlation coefficient (R) = 0.66 (p = 0.0078). When analyzing the mean lung involvement percentage of each finding, positive correlations were found between the normal lung percentage between postmortem CT and histopathology (R=0.65, p = 0.0082), as well as between ground-glass opacities in postmortem CT and normal lungs in histopathology (R=0.65, p = 0.0086), but negative correlations were observed between ground-glass opacities extension and exudative diffuse alveolar damage in histological slides (R=-0.68, p = 0.005). Additionally, it was found is a trend toward a decrease in the percentage of normal lung tissue on the histological slides as the percentage of consolidations in postmortem CT scans increased (R =-0.51, p = 0.055). The analysis of the other correlations between the percentage of each finding did not show any significant correlation or correlation trends (p ≥ 0.10). Conclusions: A minimally invasive autopsy is valid. As the severity of involvement is increased in CT, more advanced disease is seen on histopathology. However, we cannot state that one specific radiological category represents a specific pathological correspondent. Ground-glass opacities, in the postmortem stage, must be interpreted with caution, as expiratory lungs may overestimate disease.

Lung ultrasound versus chest computed tomography for pregnant inpatients with COVID-19.

PURPOSE: To compare lung ultrasound (US) and computed tomography (CT) in the assessment of pregnant women with COVID-19. METHODS: Prospective study comprising 39 pregnant inpatients with COVID-19 who underwent pulmonary assessment with CT and US with a maximum span of 48 h between the exams. The thorax was divided into 12 regions and assessed in terms of the following: the presence of B-lines (>2), coalescent B-lines, consolidation on US; presence of interlobular thickening, ground glass, consolidation on CT. The two methods were scored by adding up the scores from each thoracic region. RESULTS: A significant correlation was found between the scores obtained by the two methods (rICC = 0.946; p < 0.001). They were moderately in agreement concerning the frequency of altered pulmonary regions (weighted kappa = 0.551). In US, a score over 15, coalescent B-lines, and consolidation were predictors of the need for oxygen, whereas the predictors in CT were a lung score over 16 and consolidation. The two methods, US (p < 0.001; AUC = 0.915) and CT (p < 0.001; AUC = 0.938), were fairly accurate in predicting the need for oxygen. CONCLUSION: In pregnant women, lung US and chest CT are of similar accuracy in assessing lungs affected by COVID-19 and can predict the need for oxygen.

Contrast phase recognition in liver computer tomography using deep learning.

Hepatocellular carcinoma (HCC) has become the 4th leading cause of cancer-related deaths, with high social, economical and health implications. Imaging techniques such as multiphase computed tomography (CT) have been successfully used for diagnosis of liver tumors such as HCC in a feasible and accurate way and its interpretation relies mainly on comparing the appearance of the lesions in the different contrast phases of the exam. Recently, some researchers have been dedicated to the development of tools based on machine learning (ML) algorithms, especially by deep learning techniques, to improve the diagnosis of liver lesions in imaging exams. However, the lack of standardization in the naming of the CT contrast phases in the DICOM metadata is a problem for real-life deployment of machine learning tools. Therefore, it is important to correctly identify the exam phase based only on the image and not on the exam metadata, which is unreliable. Motivated by this problem, we successfully created an annotation platform and implemented a convolutional neural network (CNN) to automatically identify the CT scan phases in the HCFMUSP database in the city of São Paulo, Brazil. We improved this algorithm with hyperparameter tuning and evaluated it with cross validation methods. Comparing its predictions with the radiologists annotation, it achieved an accuracy of 94.6%, 98% and 100% in the testing dataset for the slice, volume and exam evaluation, respectively.

Pre-treatment MRI tumor features and post-treatment mammographic findings: may they contribute to refining the prediction of pathologic complete response in post-neoadjuvant breast cancer patients with radiologic complete response on MRI?

PURPOSE: Radiologic complete response (rCR) in breast cancer patients after neoadjuvant chemotherapy (NAC) does not necessarily correlate with pathologic complete response (pCR), a marker traditionally associated with better outcomes. We sought to verify if data extracted from two important steps of the imaging workup (tumor features at pre-treatment MRI and post-treatment mammographic findings) might assist in refining the prediction of pCR in post-NAC patients showing rCR. METHODS: A total of 115 post-NAC women with rCR on MRI (2010-2016) were retrospectively assessed. Pre-treatment MRI (lesion morphology, size, and distribution) and post-treatment mammographic findings (calcification, asymmetry, mass, architectural distortion) were assessed, as well as clinical and molecular variables. Bivariate and multivariate analyses evaluated correlation between such variables and pCR. Post-NAC mammographic findings and their correlation with ductal in situ carcinoma (DCIS) were evaluated using Pearson's correlation. RESULTS: Tumor distribution at pre-treatment MRI was the only significant predictive imaging feature on multivariate analysis, with multicentric lesions having lower odds of pCR (p = 0.035). There was no significant association between tumor size and morphology with pCR. Mammographic residual calcifications were associated with DCIS (p = 0.009). The receptor subtype remained as a significant predictor, with HR-HER2 + and triple-negative status demonstrating higher odds of pCR on multivariate analyses. CONCLUSIONS: Multicentric lesions on pre-NAC MRI were associated with a lower chance of pCR in post-NAC rCR patients. The receptor subtype remained a reliable predictor of pCR. Residual mammographic calcifications correlated with higher odds of malignancy, making the correlation between mammography and MRI essential for surgical planning. Key Points • The presence of a multicentric lesion on pre-NAC MRI, even though the patient reaches a radiologic complete response on MRI, is associated with a lower chance of pCR. • Molecular status of the tumor remained the only significant predictor of pathologic complete response in such patients in the present study. • Post-neoadjuvant residual calcifications found on mammography were related to higher odds of residual malignancy, making the correlation between mammography and MRI essential for surgical planning.

DTI-derived parameters differ between moderate and severe traumatic brain injury and its association with psychiatric scores.

BACKGROUND AND AIM: Diffusion tensor imaging (DTI) parameters in the corpus callosum have been suggested to be a biomarker for prognostic outcomes in individuals with diffuse axonal injury (DAI). However, differences between the DTI parameters on moderate and severe trauma in DAI over time are still unclear. A secondary goal was to study the association between the changes in the DTI parameters, anxiety, and depressive scores in DAI over time. METHODS: Twenty subjects were recruited from a neurological outpatient clinic and evaluated at 2, 6, and 12 months after the brain injury and compared to matched age and sex healthy controls regarding the DTI parameters in the corpus callosum. State-Trace Anxiety Inventory and Beck Depression Inventory were used to assess psychiatric outcomes in the TBI group over time. RESULTS: Differences were observed in the fractional anisotropy and mean diffusivity of the genu, body, and splenium of the corpus callosum between DAI and controls (p < 0.02). Differences in both parameters in the genu of the corpus callosum were also detected between patients with moderate and severe DAI (p < 0.05). There was an increase in the mean diffusivity values and the fractional anisotropy decrease in the DAI group over time (p < 0.02). There was no significant correlation between changes in the fractional anisotropy and mean diffusivity across the study and psychiatric outcomes in DAI. CONCLUSION: DTI parameters, specifically the mean diffusivity in the corpus callosum, may provide reliable characterization and quantification of differences determined by the brain injury severity. No correlation was observed with DAI parameters and the psychiatric outcome scores.

Repetitive Peripheral Sensory Stimulation as an Add-On Intervention for Upper Limb Rehabilitation in Stroke: A Randomized Trial.

INTRODUCTION: Repetitive peripheral sensory stimulation (RPSS) followed by 4-hour task-specific training (TST) improves upper limb motor function in subjects with stroke who experience moderate to severe motor upper limb impairments. Here, we compared effects of RPSS vs sham followed by a shorter duration of training in subjects with moderate to severe motor impairments in the chronic phase after stroke. METHODS: This single-center, randomized, placebo-controlled, parallel-group clinical trial compared effects of 18 sessions of either 1.5 h of active RPSS or sham followed by a supervised session that included 45 min of TST of the paretic upper limb. In both groups, subjects were instructed to perform functional tasks at home, without supervision. The primary outcome measure was the Wolf Motor Function Test (WMFT) after 6 weeks of treatment. Grasp and pinch strength were secondary outcomes. RESULTS: In intention-to-treat analysis, WMFT improved significantly in both active and sham groups at 3 and 6 weeks of treatment. Grasp strength improved significantly in the active, but not in the sham group, at 3 and 6 weeks. Pinch strength improved significantly in both groups at 3 weeks, and only in the active group at 6 weeks. CONCLUSIONS: The between-group difference in changes in WMFT was not statistically significant. Despite the short duration of supervised treatment, WMFT improved significantly in subjects treated with RPSS or sham. These findings are relevant to settings that impose constraints in duration of direct contact between therapists and patients. In addition, RPSS led to significant gains in hand strength.Trial Registry Name: Peripheral Nerve Stimulation and Motor Training in Stroke Clinical Trials.gov identifier: NCT0265878 https://clinicaltrials.gov/ct2/show/NCT02658578.

ACC Glu/GABA ratio is decreased in euthymic bipolar disorder I patients: possible in vivo neurometabolite explanation for mood stabilization.

Bipolar disorder (BD) is characterized by unstable mood states ranging from mania to depression. Although there is some evidence that mood instability may result from an imbalance between excitatory glutamatergic and inhibitory GABA-ergic neurotransmission, few proton magnetic resonance spectroscopy (1H-MRS) studies have measured these two neurometabolites simultaneously in BD. The enzyme glutamic acid decarboxylase (GAD1) catalyzes the decarboxylation of glutamate (Glu) to GABA, and its single nucleotide polymorphisms (SNPs) might influence Glu/GABA ratio. Thus, we investigated Glu/GABA ratio in the dorsal anterior cingulate cortex (dACC) of euthymic BD type I patients and healthy controls (HC), and assessed the influence of both mood stabilizers and GAD1 SNPs on this ratio. Eighty-eight subjects (50 euthymic BD type I patients and 38 HC) underwent 3T 1H-MRS in the dACC (2 × 2 × 4.5 cm3) using a two-dimensional JPRESS sequence and all subjects were genotyped for 4 SNPs in the GAD1 gene. BD patients had lower dACC Glu/GABA ratio compared to HC, where this was influenced by anticonvulsant and antipsychotic medications, but not lithium. The presence of GAD1 rs1978340 allele A was associated with higher Glu/GABA ratio in BD, while patients without this allele taking mood stabilizers had a lower Glu/GABA ratio. The lowering of dACC Glu/GABA could be one explanation for the mood stabilizing action of anticonvulsants and antipsychotics in BD type I euthymia. Therefore, this putative role of Glu/GABA ratio and the influence of GAD1 genotype interacting with mood stabilization medication should be confirmed by further studies involving larger samples and other mood states.ClincalTrials.gov registration: NCT01237158.

Understanding brain resilience in superagers: a systematic review.

PURPOSE: Superagers are older adults presenting excellent memory performance that may reflect resilience to the conventional pathways of aging. Our contribution aims to shape the evidence body of the known distinctive biomarkers of superagers and their connections with the Brain and Cognitive Reserve and Brain Maintenance concepts. METHODS: We performed a systematic literature search in PubMed and ScienceDirect with no limit on publication date for studies that evaluated potential biomarkers in superagers classified by validated neuropsychological tests. Methodological quality was assessed using the QUADAS-2 tool. RESULTS: Twenty-one studies were included, the majority in neuroimaging, followed by histological, genetic, cognition, and a single one on blood plasma analysis. Superagers exhibited specific regions of cortical preservation, rather than global cortical maintenance, standing out the anterior cingulate and hippocampus regions. Both superagers and controls showed similar levels of amyloid deposition. Moreover, the functional oscillation patterns in superagers resembled those described in young adults. Most of the quality assessment for the included studies showed medium risks of bias. CONCLUSION: This systematic review supports selective cortical preservation in superagers, comprehending regions of the default mode, and salience networks, overlapped by stronger functional connectivity. In this context, the anterior cingulate cortex is highlighted as an imaging and histologic signature of these subjects. Besides, the biomarkers included pointed out that the Brain and Cognitive Reserve and Brain Maintenance concepts are independent and complementary in the superagers' setting.

Does stroke laterality predict major depression and cognitive impairment after stroke? Two-year prospective evaluation in the EMMA study.

Depression and cognitive impairment are common conditions following stroke. We aimed to evaluate stroke laterality as predictor of post-stroke depression (PSD) and cognitive impairment (PCI) in a stroke cohort. Major depression (Patient Health Questionnaire-9, score ≥ 10) and cognitive impairment (Modified Telephone Interview for Cognitive Status, score < 14) were evaluated at 6 months and yearly up to 2 years. Survival analyses were performed by Kaplan-Meier curves and Cox logistic regression models, adjusted for potential confounders (cumulative hazard ratio, HR; 95% confidence interval, CI), for the likelihood of subsequent PSD or PCI progression at 6 months and 2 years, according to stroke laterality (right hemisphere-reference). Among 100 stroke patients, we found 19% had PSD and 38% had PCI 2 years after stroke. Most participants (53%) presented right-sided stroke. However, right-sided stroke was not associated with PSD or PCI. Overall, left-sided stroke was an independent and long-term predictor of PCI, but not of major depression. Left-sided stroke was associated with a high probability of PCI (42.6% and 53.2%, respectively at 6 months and 2 years, p-log-rank: 0.002). The HR of PCI due to left-sided stroke was 3.25 (95%CI, 1.30-8.12) at 6 months and remained almost the same at 2 years (HR,3.22;95%CI, 1.43-7.28). The risk of having worse cognition status increased by >3 times, 2 years after stroke. The results support the hypothesis that involvement of networks in the left, but not in the right hemisphere, contribute to long-term cognitive impairment. Lesion laterality did not influence the risk of PSD.

Adult Leukodystrophies: A Step-by-Step Diagnostic Approach.

Leukodystrophies usually affect children, but in the last several decades, many instances of adult leukodystrophies have been reported in the medical literature. Because the clinical manifestation of these diseases can be nonspecific, MRI can help with establishing a diagnosis. A step-by-step approach to assist in the diagnosis of adult leukodystrophies is proposed in this article. The first step is to identify symmetric white matter involvement, which is more commonly observed in these patients. The next step is to fit the symmetric white matter involvement into one of the proposed patterns. However, a patient may present with more than one pattern of white matter involvement. Thus, the third step is to evaluate for five distinct characteristics-including enhancement, lesions with signal intensity similar to that of cerebrospinal fluid, susceptibility-weighted MRI signal intensity abnormalities, abnormal peaks at MR spectroscopy, and spinal cord involvement-to further narrow the differential diagnosis. ©RSNA, 2019.

Distortion Correction Protocol for 3T Stereotactic Magnetic Resonance Imaging: A Clinical Study.

BACKGROUND: With application of 3T magnetic resonance imaging (MRI) to functional neurosurgery procedures and given the inherent requirement of millimetric precision, the need to develop a method for correction of geometric image distortion emerged. The aim of this study was to demonstrate clinical safety and practical viability of a correction protocol in patients scheduled to undergo stereotactic procedures using 3T MRI. METHODS: This prospective study comprised 20 patients scheduled to undergo computed tomography (CT) stereotactic functional procedures or encephalic brain lesion biopsies. The CT images were references for MRI geometric accuracy calculations. For each scan, 2 images were obtained: normal and reversed images. Eight distinct points on CT and MRI were selected summing 152 points that were based on a power analysis calculation value >0.999. One patient was excluded because of the inability to find reliable common landmark points on CT and MRI. RESULTS: The distortion range was 0-5.6 mm and increased proportionally with stereotactic isocenter distance, meaning the distortion was greater in the periphery. After correction, the minimum and maximum distortion found was 0 mm and 3.5 mm, respectively. There was no significant difference between CT and MRI corrected x-coordinates (P > 0.05). CONCLUSIONS: The proposed method can satisfactorily correct geometric distortions in clinical 3T MRI studies. Clinical use of the technique can be practical and efficient after software automation of the process. The method can be applied to all spin-echo MRI sequences.

Added value of diffusion weighted imaging in pediatric central nervous system embryonal tumors surveillance.

Diffusion weighted imaging (DWI) has an established role in primary CNS embryonal tumor (ET) characterization; however, its diagnostic utility in detecting relapse has never been determined. We aimed to compare DWI and conventional MRI sensitivity in CNS ET recurrence detection, and to evaluate the DWI properties of contrast-enhancing radiation induced lesions (RIL). Fifty-six patients with CNS ET (25 with disease relapse, 6 with RIL and 25 with neither disease relapse nor RIL) were retrospectively evaluated with DWI, conventional MRI (including both T2/FLAIR and post-contrast images), or contrast-enhanced MR imaging (CE-MRI) alone. MRI studies were independently reviewed by two neuroradiologists for detection and localization of potential brain relapses. Sensitivity for focal relapse detection was calculated for each image set on a lesion-by-lesion basis. A descriptive per subject analysis was also performed. Evaluation of follow-up MRI studies served as standard of reference. Focal recurrence detection sensitivity of DWI (96%) was significantly higher than conventional MRI (77%) and CE-MRI alone (51%) (p=0.0003 and p<0.0001). On per subject analysis there were not missed diagnoses for DWI. At the time of DWI relapse detection, conventional MRI missed 2 diagnoses, and CE-MRI 8. Analysis of medulloblastoma relapses revealed that DWI identified a higher number of focal lesions than CE-MRI in subjects with classic variant. All but one RIL did not show restricted diffusion. In conclusion, DWI is a valuable complementary technique allowing for improved detection of focal relapse in CNS ET patients, particularly in children with classic medulloblastoma, and may assist in differentiating recurrence from RIL.

Does brain creatine content rely on exogenous creatine in healthy youth? A proof-of-principle study.

It has been hypothesized that dietary creatine could influence cognitive performance by increasing brain creatine in developing individuals. This double-blind, randomized, placebo-controlled, proof-of-principle study aimed to investigate the effects of creatine supplementation on cognitive function and brain creatine content in healthy youth. The sample comprised 67 healthy participants aged 10 to 12 years. The participants were given creatine or placebo supplementation for 7 days. At baseline and after the intervention, participants undertook a battery of cognitive tests. In a random subsample of participants, brain creatine content was also assessed in the regions of left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe by proton magnetic resonance spectroscopy (1H-MRS) technique. The scores obtained from verbal learning and executive functions tests did not significantly differ between groups at baseline or after the intervention (all p > 0.05). Creatine content was not significantly different between groups in left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe (all p > 0.05). In conclusion, a 7-day creatine supplementation protocol did not elicit improvements in brain creatine content or cognitive performance in healthy youth, suggesting that this population mainly relies on brain creatine synthesis rather than exogenous creatine intake to maintain brain creatine homeostasis.

Abdominal manifestations of fishbone perforation: a pictorial essay.

PURPOSE: The present article provides an overview of the spectrum of abdominal presentations of fishbone (FB) ingestion and its complications. METHODS: In image data from 9 patients, FB perforations were found in different levels of the gastrointestinal tract (GIT), including duodenal, jejunal, and sigmoid perforations; in 4 asymptomatic patients, FBs were observed in the mesentery, falciform ligament, and intestinal bowel. RESULTS: The main imaging features of FB perforation were focal gastric or intestinal wall thickening, fat stranding, bowel obstruction, ascites, localized pneumoperitoneum, intra-abdominal abscess, liver abscess, and a linear hyperdense structure in the abdominal cavity in the GIT or within a parenchymal organ often surrounded by inflammatory changes. Free pneumoperitoneum was rare. CONCLUSION: Although in most cases, a FB does not cause any serious complications, an inflammatory process and complications may occur when it perforates the stomach or bowel loops. Radiologists need to be aware of the possibility of FB perforation, especially in high-risk patients, because it is not always considered in the differential diagnosis by referring physicians and can mimic other inflammatory conditions and tumoral lesions.

Anterior cingulate Glutamate-Glutamine cycle metabolites are altered in euthymic bipolar I disorder.

Bipolar disorder (BD) has been consistently associated with abnormalities in the Glutamate/GABA-Glutamine cycle. Magnetic resonance spectroscopy (MRS) studies have reported increased brain Glutamate (Glu) and Glx (Glu+Glutamine) in subjects with BD. However, data on separate measures of GABA and Glutamine (Gln) in BD are sparse due to overlapping resonant signals. The development of new sequence methods in the quantification of these metabolites has allowed a better understanding of the Glu/GABA-Gln cycle but data on this field of research remains sparse in BD. Eighty-eight subjects (50 euthymic BD and 38 HC) underwent 3T proton magnetic resonance spectroscopy (1H MRS) in the anterior cingulate cortex (ACC; 2×2×4.5cm(3)) using a two-dimensional JPRESS sequence. GABA, Glutamine (Gln) and Glutamate (Glu) were quantified with the ProFit program. Using image segmentation and known creatine (Cre) concentrations for white and grey matter, metabolite concentrations were calculated for the excited MRS voxel. GABA levels did not differ between groups. Gln level was higher in euthymic BD patients than in healthy controls. The Glu level and Glu/Gln ratio were lower in BD patients than in controls. The use of anticonvulsants was associated with Gln increase but did not affect Glu or Glu/Gln. Neither lithium nor antipsychotic use influenced metabolite levels. The ACC MRS findings indicate that the glutamatergic function in euthymic medicated BD patients is altered relative to controls. Whether this feature is a metabolic signature of euthymic BD subjects should be the focus of future studies.

Assessment of irradiated brain metastases using dynamic contrast-enhanced magnetic resonance imaging.

INTRODUCTION: The purpose of this study was to evaluate the effect of stereotactic radiosurgery (SRS) on cerebral metastases using the transfer constant (K trans) assessed by dynamic contrast-enhanced (DCE) MRI. Furthermore, we aimed to evaluate the ability of K trans measurements to predict midterm tumor outcomes after SRS. METHODS: The study received institutional review board approval, and informed consent was obtained from all subjects. Twenty-six adult patients with a total of 34 cerebral metastases underwent T1-weighted DCE MRI in a 1.5-T magnet at baseline (prior to SRS) and 4-8 weeks after treatment. Quantitative analysis of DCE MRI was performed by generating K trans parametric maps, and region-of-interest-based measurements were acquired for each metastasis. Conventional MRI was performed at least 16 weeks after SRS to assess midterm tumor outcome using volume variation. RESULTS: The mean (±SD) K trans value was 0.13 ± 0.11 min(-1) at baseline and 0.08 ± 0.07 min(-1) after 4-8 weeks post-treatment (p < 0.001). The mean (±SD) total follow-up time was 7.9 ± 4.7 months. Seventeen patients (22 lesions) underwent midterm MRI. Of those, nine (41 %) lesions had progressed at the midterm follow-up. An increase in K trans after SRS was predictive of tumor progression (hazard ratio = 1.50; 95 % CI = 1.16-1.70, p < 0.001). An increase of 15 % in K trans showed a sensitivity of 78 % and a specificity of 85 % for the prediction of progression at midterm follow-up. CONCLUSION: SRS was associated with a reduction of K trans values of the cerebral metastases in the early post-treatment period. Furthermore, K trans variation as assessed using DCE MRI may be helpful to predict midterm outcomes after SRS.

An image correction protocol to reduce distortion for 3-T stereotactic MRI.

BACKGROUND: Image distortion limits application of direct 3-T magnetic resonance imaging for stereotactic functional neurosurgery. OBJECTIVE: To test the application of a method to correct and curtail image distortion of 3-T magnetic resonance images. METHODS: We used a phantom head model mounted on a platform with the dimensions and features of a stereotactic frame. The phantom was scanned within the head coil of a Philips Achieva 3T X series (Philips Medical Systems, Eindhoven, the Netherlands). For each scan, 2 images were obtained-the normal and the reversed images. We applied the inverted gradient correction protocol to produce a corrected x, y, and z coordinates. We applied the Cronbach test or coefficient of reliability to assess the internal consistency of the data. RESULTS: For all analyzed data, the P value was >.05, indicating that the differences among the observers were not statistically significant. Moreover, the data rectification proved to be effective, as the average distortion after correction was 1.05 mm. The distortion varied between 0.7 mm and 3.7 mm, depending on the target location. CONCLUSION: This study examined a rectifying technique for correcting geometric distortion encountered in magnetic resonance images related to static field inhomogeneities (resonance offsets), and the technique proved to be highly successful in producing consistently accurate stereotactic target registration. The technique is applicable to all routinely used spin-echo MRI.

Characteristics related to TMJ arthralgia, visualized by magnetic resonance imaging (3.0 Tesla).

PATIENTS: Six women, with ages ranging from 52 to 64 years old, clinically evaluated (Research Diagnostic Criteria for Temporomandibular Disorders) by a single examiner were submitted to MRI (3.0 T). They had only arthralgia diagnosis. The images were evaluated by two radiologists who were not informed about the patients' clinical conditions, in which discs displacements, osteophytes and morphological irregularities, as well as completely normal images, i.e., without any characteristics were identified. DISCUSSION: TMJ arthralgia can be caused by various conditions, few of which are objectively observed when investigating its causes or diagnose temporomandibular disorders (TMD). In some cases, imaging exams can detect some conditions and magnetic resonance imaging (MRI) is commonly used for this purpose. Here, the MRI (3.0 T) enabled a detailed visualization of the structures of the TMJ, allowing the characterization of the symptomology in some cases. Despite, some images were completely normal. CONCLUSION: This case report detected some features seen on the MRI that justified a clinical diagnosis arthralgia, not associated with other clinical diagnosis. However, the detailed clinical examination should be sovereign even in the face of equipment with advanced technology.

The correlation of research diagnostic criteria for temporomandibular disorders and magnetic resonance imaging: a study of diagnostic accuracy.

OBJECTIVE: The aim of this study was to evaluate the performance of research diagnostic criteria for temporomandibular disorders (RDC/TMD) as a diagnostic test for temporomandibular joint problems using magnetic resonance imaging (MRI) as the gold standard. STUDY DESIGN: Sixty-seven women were assessed with RDC/TMD (2 examiners) and underwent MRI examination (3.0 T). Images were evaluated by 2 independent radiologists blinded to the clinical diagnoses. Results were analyzed by the Catmaker system. RESULTS: Of the 67 patients, 44 were diagnosed with temporomandibular disorders (TMD) according to RDC/TMD, but 21 (32%) of the diagnoses were not confirmed by MRI. The RDC/TMD sensitivity was 83.0%, specificity was 53.0%, and the positive likelihood ratio was 1.77, whereas the negative likelihood ratio was 0.32 (P = 0.16). CONCLUSIONS: Our data suggest that RDC/TMD is a good research tool, but the high rate of false-positive results limits its use in clinical practice.

The benign spectrum of hypothalamic hamartomas: infrequent epilepsy and normal cognition in patients presenting with central precocious puberty.

PURPOSE: Hypothalamic hamartoma (HH) is the main structural cause of central precocious puberty (CPP). HH is frequently associated with cognitive impairment and epileptic encephalopathies. Disease severity in case series from neurology services may be biased towards more neurologically impaired patients. AIM: To perform a prospective cognitive evaluation in patients with HH presenting with CPP in an endocrinology outpatient clinic setting. METHODS: We evaluated fifteen consecutive patients with CPP due to HH presenting to an endocrinology outpatient clinic. CPP was diagnosed at a median age of 0.7 yr (0.4-7 yr). Mean age at neurologic evaluation was 13.9 yrs. Eight patients (53.3%) were male. Epileptic seizures occurred in 5/15 (33%) patients. Two patients presented a single unprovoked seizure (SUS). Three patients were diagnosed with epilepsy. Cognitive evaluation, using age-appropriate Wechsler Intelligence Scale, was performed in 11 patients. RESULTS: All patients without epilepsy, including two patients with a history of a SUS, had normal neurologic and cognitive evaluation. Epilepsy and SUS were only seen in patients with sessile HH. Three patients with epilepsy presented cognitive or behavioral findings. Reduced intelligence quotients (IQ), in the borderline range, were noted in both patients with epilepsy who underwent full cognitive evaluation. We found no significant correlation between HH diameter or shape and mean full-scale IQ. CONCLUSIONS: Patients who presented with isolated CPP without epilepsy displayed normal cognition when evaluated after a mean period of 13 years. Occurrence of epilepsy, seen in a minority of patients, but not of a single seizure, was associated with mild cognitive deficit and behavioral disturbances in this case series.