An Enhanced Visualization of DBT Imaging Using Blind Deconvolution and Total Variation Minimization Regularization

Digital Breast Tomosynthesis (DBT) presents out-of-plane artifacts caused by features of high intensity. Given observed data and knowledge about the point spread function (PSF), deconvolution techniques recover data from a blurred version. However, a correct PSF is difficult to achieve and these methods amplify noise. When no information is available about the PSF, blind deconvolution can be used. Additionally, Total Variation (TV) minimization algorithms have achieved great success due to its virtue of preserving edges while reducing image noise. This work presents a novel approach in DBT through the study of out-of-plane artifacts using blind deconvolution and noise regularization based on TV minimization. Gradient information was also included. The methodology was tested using real phantom data and one clinical data set. The results were investigated using conventional 2D slice-by-slice visualization and 3D volume rendering. For the 2D analysis, the artifact spread function (ASF) and Full Width at Half Maximum (FWHMMASF) of the ASF were considered. The 3D quantitative analysis was based on the FWHM of disks profiles at 90°, noise and signal to noise ratio (SNR) at 0° and 90°. A marked visual decrease of the artifact with reductions of FWHMASF (2D) and FWHM90° (volume rendering) of 23.8% and 23.6%, respectively, was observed. Although there was an expected increase in noise level, SNR values were preserved after deconvolution. Regardless of the methodology and visualization approach, the objective of reducing the out-of-plane artifact was accomplished. Both for the phantom and clinical case, the artifact reduction in the z was markedly visible

Ten-year follow-up of a giant prolactinoma

Giant prolactinomas are rare pituitary tumours of which management can be a challenge. A 28-year-old man presented with headaches, visual impairment and behavioural changes. Clinically, the patient was found to have hypogonadism and bitemporal hemianopsia. A MRI demonstrated a pituitary tumour 76 mm in diameter and blood tests revealed a serum prolactin of 158 700 µU/mL (reference range 58-254). Initially, a craniotomy was performed. Immunohistochemistry of the tumour identified a prolactinoma with a high proliferative index and the patient was started on treatment with a dopamine agonist. A year later, neurological symptoms worsened due to regrowth of the lesion's cystic component, and so further surgery was performed. After 10 years of treatment with dopamine agonists, the prolactin levels decreased by 96.8%, there was an effective reduction in tumour size, and the neurological signs and symptoms resolved

Development of a PCR-RFLP marker to genetically distinguish Prosorhynchus crucibulum and Prosorhynchus aculeatus

The cercariae stages of Prosorhynchus crucibulum and Prosorhynchus aculeatus are morphologically indistinguishable. However, the differentiation of these two species is crucial to understand the transmission dynamics between these primary hosts (mussels) and the secondary hosts (fish). In this way, the objective of this study is to develop an accurate molecular identification too] to differentiate the cercariae stage of P. crucibulum and P. aculeatus. We targeted the 18S nuclear ribosomal DNA region by PCR amplification and sequenced this amplicon. By generating these sequences, we developed a RFLP tool with the use of the enzymes Hincll and FokI that produced different restriction profiles between P. crucibulum and P. aculeatus. Each enzyme generated different-sized fragments specific to the species examined and no cross-reaction between the species was detected in their restriction pattern. By sequencing, no intraspecific-polymorphism was detected since there is 100% homology among A aculeatus or A crucibulum. These results indicate that PCR-linked restriction analysis of the 18S rDNA region provided us with rapid and reliable molecular tools for distinction of the cercariae of these species. The sequences generated were deposited in GenBank accession numbers for P. crucibulum cercariae (FJ463407, FJ463408 and FJ463409) and adult worm (FJ429096, FJ429097), and for A aculeatus adult (FJ429094 and FJ429095). (C) 2009 Elsevier Ireland Ltd. All rights reserved

From juvenile parkinsonism to encephalitis lethargica, a new phenotype of post-streptococcal disorders: case report.

We report the case of a 16-year-old boy presented with a mild akinetic-rigid parkinsonism shortly after a post-streptococcal infection. After stopping corticoids, he had a rapid neurological deterioration to a fatal encephalitis lethargica-like syndrome. Serum analysis demonstrated consistently elevated anti-streptolysin-O. This case illustrates a new severe phenotype in the spectrum of the post-streptococcal disorders. This etiology should be considered in the differential diagnosis of a movement disorder with a rapid detrimental evolution

Probable acute disseminated encephalomyelitis due to Haemophilus influenzae meningitis

We report the case of a 17-year-old male on long-term steroid therapy for minimal lesion glomerulopathy who, after an upper respiratory infection, presented with Haemophilus influenzae type b meningitis. Twenty-four hours later he developed depression of consciousness which progressed to coma and left hemiparesis. Brain magnetic resonance imaging (MRI) revealed multiple lesions (hyperintense on T2 and slightly hypointense on Tl) involving mainly white matter suggestive of inflammation. MRI features were compatible with acute disseminated encephalomyelitis (ADEM), although a differential diagnosis included cerebritis or vasculitis, secondary to bacterial meningitis. The patient was treated with high-dose steroids which resulted in a gradual improvement followed by complete clinical recovery. We propose a diagnosis of ADEM was the best diagnosis because of the radiological features and response to steroids. The occurrence of ADEM associated with acute meningitis, however rare, represents an important diagnostic challenge for the clinician

Autophagy and mitochondrial metabolism: insights into the role and therapeutic potential in chronic myeloid leukaemia

Despite the development of selective BCR‐ABL‐targeting tyrosine kinase inhibitors (TKIs) transforming the management of chronic myeloid leukaemia (CML), therapy‐resistant leukaemic stem cells (LSCs) persist after TKI treatment and present an obstacle to a CML cure. Recently, we and others have made significant contributions to the field by unravelling survival dependencies in LSCs to work towards the goal of eradicating LSCs in CML patients. In this review, we describe these findings focusing on autophagy and mitochondrial metabolism, which have recently been uncovered as two essential processes for LSCs quiescence and survival, respectively. In addition, we discuss the therapeutic potential of autophagy and mitochondrial metabolism inhibition as a strategy to eliminate CML cells in patients where the resistance to TKI is driven by BCR‐ABL‐independent mechanism(s)

Impact of total variation minimization in volume rendering visualization of breast tomosynthesis data

Background and objective: Total Variation (TV) minimization algorithms have achieved great attention due to the virtue of decreasing noise while preserving edges. The purpose of this work is to implement and evaluate two TV minimization methods in 3D. Their performance is analyzed through 3D visualization of digital breast tomosynthesis (DBT) data with volume rendering. Methods: Both filters were studied with real phantom and one clinical DBT data. One algorithm was applied sequentially to all slices and the other was applied to the entire volume at once. The suitable Lagrange multiplier used in each filter equation was studied to reach the minimum 3D TV and the maximum contrast-to-noise ratio (CNR). Imaging blur was measured at 0° and 90° using two disks with different diameters (0.5 mm and 5.0 mm) and equal thickness. The quality of unfiltered and filtered data was analyzed with volume rendering at 0° and 90°. Results: For phantom data, with the sequential filter, a decrease of 25% in 3D TV value and an increase of 19% and 30% in CNR at 0° and 90°, respectively, were observed. When the filter is applied directly in 3D, TV value was reduced by 35% and an increase of 36% was achieved both for CNR at 0° and 90°. For the smaller disk, variations of 0% in width at half maximum (FWHM) at 0° and a decrease of about 2.5% for FWHM at 90° were observed for both filters. For the larger disk, there was a 2.5% increase in FWHM at 0° for both filters and a decrease of 6.28% and 1.69% in FWHM at 90° with the sequential filter and the 3D filter, respectively. When applied to clinical data, the performance of each filter was consistent with that obtained with the phantom. Conclusions: Data analysis confirmed the relevance of these methods in improving quality of DBT images. Additionally, this type of 3D visualization showed that it may play an important complementary role in DBT imaging. It allows to visualize all DBT data at once and to analyze properly filters applied to all the three dimensions

Use (or Misuse) of Drugs in Pediatrics

Introdução e Objectivos: A exposição a fármacos na idade pediátrica pode ser nociva. A utilização elevada de medicamentos não aprovados em Pediatria, bem como o uso para sintomas em que a sua eficácia não foi comprovada, tem sido descrita de forma preocupante. Foi objectivo deste estudo avaliar o padrão de consumo de fármacos numa população pediátrica portuguesa. Métodos: Estudo transversal, com recrutamento prospectivo dos casos e amostra de conveniência; recolha de dados por inquérito; incluídas crianças, sem doença crónica, que recorreram ao serviço de urgência de um hospital na área da Grande Lisboa, num período de dois meses. Resultados: Foram incluídas 189 crianças com idade média de 5,8 anos. A proporção de crianças com consumo de fármacos, nos trêsmeses precedentes, foi de 120/189 (63,5%) – superior entre os seis e 24 meses (74%vs 58,5%; p=0,038).Os fármacos mais prescritos foram os analgésicos/antipiréticos e anti-inflamatórios (83/202, 41,1%), os antibióticos (52/202, 25,8%) e os anti-histamínicos (14/202, 7%). Em 96/202 casos (47,5%) eram medicamentos não sujeitos a receita médica e em 33/174 (19,1%) “automedicações”. Verificou-se utilização de anti-histamínicos, expectorantes, analgésicos e anti-inflamatórios não recomendados para a faixa etária. O consumo de antibióticos foi mais elevado entre os seis e 24 meses (36%vs 18,5%; p=0,012), com predomínio da associação amoxicilina/ácido clavulânico (21/52, 40,4%). Em seis casos foram relatados possíveis efeitos secundários. Conclusões: De acordo com o nosso conhecimento este é o primeiro estudo em Portugal a avaliar o padrão de utilização de fármacos em Pediatria. Este consumo foi elevado, sobretudo na infância precoce, evidenciando a necessidade de vigilância e regulamentação adequadas. Os medicamentos não sujeitos a receita médica, amplamente utilizados, poderão associar-se a riscos acrescidos, pela facilidade no seu acesso. O uso frequente de antibióticos, sobretudo de largo espectro, poderá vir a associar-se ao desenvolvimento de resistências