Computer-Aided Diagnosis of Vertebral Compression Fractures Using Convolutional Neural Networks and Radiomics

Journal of Digital Imaging - Vertebral Compression Fracture (VCF) occurs when the vertebral body partially collapses under the action of compressive forces. Non-traumatic VCFs can be secondary to...     

Expressed emotion and family burden in relatives of patients in first-episode psychosis

BACKGROUND

Evidence suggests that expressed emotion (EE) and family burden (FB) are phenomena that interact, but there is a lack of studies that analyze this association in patients in first-episode psychosis.

Proposal of abolition of the skin sensitivity test before equine rabies immune globulin application

An epizootic outbreak of rabies occurred in 1995 in Ribeir?o Preto, SP, with 58 cases of animal rabies (54 dogs, 3 cats and 1 bat) confirmed by the Pasteur Institute of S?o Paulo, and one human death. The need to provide care to a large number of people for the application of equine rabies immune globulin (ERIG) prevented the execution of the skin sensitivity test (SST) and often also the execution of desensitization, procedures routinely used up to that time at the Emergency Unit of the University Hospital of the Faculty of Medicine of Ribeir?o Preto, University of S?o Paulo (EU-UHFMRP-USP), a reference hospital for the application of heterologous sera. In view of our positive experience of several years with the abolition of SST and of the use of premedication before the application of antivenom sera, we used a similar schedule for ERIG application. Of the 1489 victims of animal bites, 1054 (71%) received ERIG; no patient was submitted to SST and all received intravenously anti-histamines (anti-H1 + anti-H2) and corticosteroids before the procedure. The patients were kept under observation for 60 to 180 minutes and no adverse reaction was observed. On the basis of these results, since December 1995 ERIG application has been decentralized in Ribeir?o Preto and has become the responsibility of the Emergency Unit of the University Hospital and the Central Basic Health Unit, where the same routine is used. Since then, 4216 patients have received ERIG (1818 at the Basic Health Unit and 2398 at the EU-UHFMRP), with no problems. The ideal would be the routine use of human rabies immune globulin (HRIG) in public health programs, but this is problematic, because of their high cost. However, while this does not occur, the use of SST is no longer justified at the time of application of ERIG, in view of the clinical evidence of low predictive value and low sensitivity of SST involving the application of heterologous sera. It is very important to point out that a negative SST result may lead the health team to a feeling of false safety that no adverse reaction will occur, but this is not true for the anaphylactoid reactions. The decision to use premedication, which is based on knowledge about anaphylaxis and on the pharmacology of the medication used, is left to the judgment of health professionals, who should always be prepared for eventual untoward events.     

Reducing the semantic gap in content-based image retrieval in mammography with relevance feedback and inclusion of expert knowledge

Object

We investigate the use of relevance feedback (RFb) and the inclusion of expert knowledge to reduce the semantic gap in content-based image retrieval (CBIR) of mammograms.

Materials and methods

Tests were conducted with radiologists, in which their judgment of the relevance of the retrieved images was used with techniques of query-point movement to incorporate RFb. The measures of similarity of images used for CBIR were based upon textural characteristics and the distribution of density of fibroglandular tissue in the breast. The features used include statistics of the gray-level histogram, texture features based upon the gray-level co-occurrence matrix, moment-based features, measures computed in the Radon domain, and granulometric measures. Queries for CBIR with RFb were executed by three radiologists. The performance of CBIR was measured in terms of precision of retrieval and a measure of relevance-weighted precision (RWP) of retrieval.

Results

The results indicate improvement due to RFb of up to 62% in precision and 39% in RWP.

Conclusion

The gain in performance of CBIR with RFb depended upon the BI-RADS breast density index of the query mammographic image, with greater improvement in cases of mammograms with higher density.     

Immediate hypersensitivity reactions after intravenous use of antivenin sera: prognostic value of intradermal sensitivity tests]

The frequency and class of immediate-type hypersensitivity manifestations were studied in 494 snakebitten and scorpion stung patients who were treated with intravenous injections of antivenom sera. These patients were admitted to HC-FMRPUSP from 1983 to 1988. The effectiveness of a hypersensitivity skin test was also investigated. Eighty two out of 320 patients admitted following snake bites (25.6%) had immediate-type reactions consisting of isolated skin lesions (40%), skin lesions plus respiratory manifestations (19%) and gastrointestinal involvement (17%). Anaphylactic shock occurred in ten patients (12%). Thirteen out of 174 patients admitted following scorpion stings had immediate-type reactions (7.5%). There was also a preponderance of skin reactions. Anaphylactic shock was observed in one patient. The positive predictive value of hypersensitivity skin test was 31.8% and its sensibility was 54.8%. These data show that a hypersensitivity skin test is ineffective in predicting immediate-type hypersensitivity manifestations in patients given snake and scorpion antivenom. Considering these results, this test should be eliminated as a routine procedure when treating victims of poisonous animals. These studies indicate that prior to the administration of antivenom anti-histamine (H1- and H2-antagonists) as well corticosteroids should be given by i.v. route in order to prevent or reduce hypersensitivity reactions. Antivenom sera must always be given under continuous medical surveillance by an intravenous route, without dilution, drop by drop for 15-30 minutes.     

Acute myocardial infarction-like enzyme profile in human victims of Crotalus durissus terrificus envenoming

The clinical signs and symptoms of Crotalus durissus terrificus envenoming are due to the neurotoxic, myotoxic systemic and thrombin-like coagulating effects of the venom. The rhabdomyolysis observed after envenoming caused by snakes, the venom of which has a systemic myotoxic activity, has been limited thus far to skeletal muscle, with no reports of myocardial damage. In the present paper we report serial measurements of serum creatine kinase (CK), lactic dehydrogenase (LD) and of CK-MB and LD1 isoenzymes in human victims of Crotalus bites. The results were similar to those reported for acute myocardial infarction even though the clinical evolution, electrocardiogram and echocardiogram findings did not show any involvement of cardiac muscle. The enzymatic profile detected, as well as the pattern of focal involvement observed in muscle biopsies obtained from these patients, suggest that there may be a type of skeletal muscle fibre that is preferentially damaged by C. durissus terrificus venom, i.e., type I and/or IIa fibres, the composition of which is richer in CK-MB and LD1, and is similar to that of cardiac fibres.     

Neural Correlates of Depressive Symptoms in Smokers – A Systematic Review of Imaging Studies

This review aims to summarize neuroimaging studies in order to better understand the neural correlates of depressive symptoms in tobacco smokers. Using the keywords “depressive OR depression” AND “tobacco OR nicotine OR smok^* OR cigarette” AND “neuroimage OR magnetic resonance OR smri OR structural magnetic resonance OR fmri OR functional magnetic resonance OR pet OR positron emission tomography”, literature search was conducted in PubMed, Web of Science and PsycINFO databases. The first and the last author read the abstracts of all the studies found in the search (n = 179). The inclusion and exclusion criteria were applied and 150 articles were excluded. Then, both authors assessed the remaining 29 studies for eligibility and 16 studies were included in the present review. In the phase of active/chronic smoking, depressive symptoms are characterized as comorbidity related to an enhancement of dopamine release, and smokers have decreased Monoamine oxidase A (MAO-A). Stimuli-related functional magnetic resonance imaging (Stimuli-fMRI) studies also show that there is a positive correlation between the level of depressive symptoms and a greater response to general negative stimuli in active/chronic smokers. In the withdrawal phase, depressive symptoms are related to the withdrawal syndrome and increased MAO-A. Stimuli-fMRI studies show that there is a negative correlation between level of depressive symptoms and reactivity to negative stimuli in recent abstinent smokers. Major areas of the reward system such as the striatum and areas related to impulse control are activated to a greater extent in depressive smokers compared to non-depressed smokers.     

Endowing a Content-Based Medical Image Retrieval System with Perceptual Similarity Using Ensemble Strategy

Content-based medical image retrieval (CBMIR) is a powerful resource to improve differential computer-aided diagnosis. The major problem with CBMIR applications is the semantic gap, a situation in which the system does not follow the users’ sense of similarity. This gap can be bridged by the adequate modeling of similarity queries, which ultimately depends on the combination of feature extractor methods and distance functions. In this study, such combinations are referred to as perceptual parameters, as they impact on how images are compared. In a CBMIR, the perceptual parameters must be manually set by the users, which imposes a heavy burden on the specialists; otherwise, the system will follow a predefined sense of similarity. This paper presents a novel approach to endow a CBMIR with a proper sense of similarity, in which the system defines the perceptual parameter depending on the query element. The method employs ensemble strategy, where an extreme learning machine acts as a meta-learner and identifies the most suitable perceptual parameter according to a given query image. This parameter defines the search space for the similarity query that retrieves the most similar images. An instance-based learning classifier labels the query image following the query result set. As the concept implementation, we integrated the approach into a mammogram CBMIR. For each query image, the resulting tool provided a complete second opinion, including lesion class, system certainty degree, and set of most similar images. Extensive experiments on a large mammogram dataset showed that our proposal achieved a hit ratio up to 10% higher than the traditional CBMIR approach without requiring external parameters from the users. Our database-driven solution was also up to 25% faster than content retrieval traditional approaches.     

A population-based morphometric MRI study in patients with first-episode psychotic bipolar disorder: comparison with geographically matched healthy controls and major depressive disorder subjects

Périco CA‐M, Duran FLS, Zanetti MV, Santos LC, Murray RM, Scazufca M, Menezes PR, Busatto GF, Schaufelberger MS. A population‐based morphometric MRI study in patients with first‐episode psychotic bipolar disorder: comparison with geographically matched healthy controls and major depressive disorder subjects.
Bipolar Disord 2011: 13: 28–40. © 2011 The Authors.
Journal compilation © 2011 John Wiley & Sons A/S. Objectives: Many morphometric magnetic resonance imaging (MRI) studies that have investigated the presence of gray matter (GM) volume abnormalities associated with the diagnosis of bipolar disorder (BD) have reported conflicting findings. None of these studies has compared patients with recent‐onset psychotic BD with asymptomatic controls selected from exactly the same environment using epidemiological methods, or has directly contrasted BD patients against subjects with first‐onset psychotic major depressive disorder (MDD). We examined structural brain differences between (i) BD (type I) subjects and MDD subjects with psychotic features in their first contact with the healthcare system in Brazil, and (ii) these two mood disorder groups relative to a sample of geographically matched asymptomatic controls. Methods: A total of 26 BD subjects, 20 subjects with MDD, and 94 healthy controls were examined using either of two identical MRI scanners and acquisition protocols. Diagnoses were based on DSM‐IV criteria and confirmed one year after brain scanning. Image processing was conducted using voxel‐based morphometry. Results: The BD group showed increased volume of the right dorsal anterior cingulate cortex relative to controls, while the MDD subjects exhibited bilateral foci GM deficits in the dorsolateral prefrontal cortex (p < 0.05, corrected for multiple comparisons). Direct comparison between BD and MDD patients showed a focus of GM reduction in the right‐sided dorsolateral prefrontal cortex (p < 0.05, corrected for multiple comparisons) and a trend (p < 0.10, corrected) toward left‐sided GM deficits in the dorsolateral prefrontal cortex of MDD patients. When analyses were repeated with scanner site as a confounding covariate the finding of increased right anterior cingulate volumes in BD patients relative to controls remained statistically significant (p = 0.01, corrected for multiple comparisons). Conclusions: These findings reinforce the view that there are important pathophysiological distinctions between BD and MDD, and indicate that subtle dorsal anterior cingulate abnormalities may be relevant to the pathophysiology of BD.