A novel framework for MR image segmentation and quantification by using MedGA.

BACKGROUND AND OBJECTIVES: Image segmentation represents one of the most challenging issues in medical image analysis to distinguish among different adjacent tissues in a body part. In this context, appropriate image pre-processing tools can improve the result accuracy achieved by computer-assisted segmentation methods. Taking into consideration images with a bimodal intensity distribution, image binarization can be used to classify the input pictorial data into two classes, given a threshold intensity value. Unfortunately, adaptive thresholding techniques for two-class segmentation work properly only for images characterized by bimodal histograms. We aim at overcoming these limitations and automatically determining a suitable optimal threshold for bimodal Magnetic Resonance (MR) images, by designing an intelligent image analysis framework tailored to effectively assist the physicians during their decision-making tasks. METHODS: In this work, we present a novel evolutionary framework for image enhancement, automatic global thresholding, and segmentation, which is here applied to different clinical scenarios involving bimodal MR image analysis: (i) uterine fibroid segmentation in MR guided Focused Ultrasound Surgery, and (ii) brain metastatic cancer segmentation in neuro-radiosurgery therapy. Our framework exploits MedGA as a pre-processing stage. MedGA is an image enhancement method based on Genetic Algorithms that improves the threshold selection, obtained by the efficient Iterative Optimal Threshold Selection algorithm, between the underlying sub-distributions in a nearly bimodal histogram. RESULTS: The results achieved by the proposed evolutionary framework were quantitatively evaluated, showing that the use of MedGA as a pre-processing stage outperforms the conventional image enhancement methods (i.e., histogram equalization, bi-histogram equalization, Gamma transformation, and sigmoid transformation), in terms of both MR image enhancement and segmentation evaluation metrics. CONCLUSIONS: Thanks to this framework, MR image segmentation accuracy is considerably increased, allowing for measurement repeatability in clinical workflows. The proposed computational solution could be well-suited for other clinical contexts requiring MR image analysis and segmentation, aiming at providing useful insights for differential diagnosis and prognosis

A Low-Dose CT-Based Radiomic Model to Improve Characterization and Screening Recall Intervals of Indeterminate Prevalent Pulmonary Nodules.

Lung cancer (LC) is currently one of the main causes of cancer-related deaths worldwide. Low-dose computed tomography (LDCT) of the chest has been proven effective in secondary prevention (i.e., early detection) of LC by several trials. In this work, we investigated the potential impact of radiomics on indeterminate prevalent pulmonary nodule (PN) characterization and risk stratification in subjects undergoing LDCT-based LC screening. As a proof-of-concept for radiomic analyses, the first aim of our study was to assess whether indeterminate PNs could be automatically classified by an LDCT radiomic classifier as solid or sub-solid (first-level classification), and in particular for sub-solid lesions, as non-solid versus part-solid (second-level classification). The second aim of the study was to assess whether an LCDT radiomic classifier could automatically predict PN risk of malignancy, and thus optimize LDCT recall timing in screening programs. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, positive predictive value, negative predictive value, sensitivity, and specificity. The experimental results showed that an LDCT radiomic machine learning classifier can achieve excellent performance for characterization of screen-detected PNs (mean AUC of 0.89 ± 0.02 and 0.80 ± 0.18 on the blinded test dataset for the first-level and second-level classifiers, respectively), providing quantitative information to support clinical management. Our study showed that a radiomic classifier could be used to optimize LDCT recall for indeterminate PNs. According to the performance of such a classifier on the blinded test dataset, within the first 6 months, 46% of the malignant PNs and 38% of the benign ones were identified, improving early detection of LC by doubling the current detection rate of malignant nodules from 23% to 46% at a low cost of false positives. In conclusion, we showed the high potential of LDCT-based radiomics for improving the characterization and optimizing screening recall intervals of indeterminate PNs

MENINGOENCEPHALITIS DUE TO VARICELLA ZOSTER VIRUS IN AIDS PATIENTS. REPORT OF ELEVEN CASES AND REVIEW OF THE LITERATURE

Neurological complications of varicella-zoster virus (VZV) are infrequent and include various clinical pictures. The reactivation of VZV in patients with AIDS is generally associated with an acute and severe meningoencephalitis. We report the epidemiological, clinical and virological data from 11 consecutive patients with diagnosis of HIV/AIDS and central nervous system (CNS) involvement due to VZV. All patients were male and seropositive for HIV. The primary risk factor for HIV infection was unprotected sexual contact. The median of CD4 T cell count was 142 cells/µL. All of them presented signs and symptoms of meningoencephalitis. Six patients (54.5%) presented pleocytosis; they all showed high CSF protein concentrations with a median of 2.1 g/dL. Polymerase chain reaction of cerebrospinal fluid specimen was positive for VZV in all of them and they were treated with intravenous acyclovir at doses of 30/mg/kg/day for 21 days. Overall survival was 63% (7 of 11 patients). The four dead patients had low cellular counts in CSF, below the median of this parameter. VZV should be included among the opportunistic pathogens that can involve CNS with a diffuse and severe meningoencephalitis in patients with advanced HIV/AIDS disease

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Refractory recurrent bleeding as a late mortal complication of chest wall irradiation

Radiation therapy is used to treat breast malignancies. Old external radiotherapy protocols included high-dose schedules and were associated with late complications. We describe the case of a 72-year-old woman who was admitted with recurrent bleeding from chest wall. Arteriovenous fistulae were diagnosed. Embolization therapy was initially successful, even though the bleeding episodes became recurrent. Arteriovenous fistulae should be included among differential diagnosis of thoracic bleeding in patients with history of local radiation therapy. The prognosis is poor and endovascular treatment may be considered a first-line treatment

Mielitis subaguda como forma de presentación de sífilis en una paciente inmunocompetente

La neuros&iacute;filis se asocia con distintos s&iacute;ndromes cl&iacute;nicos neurol&oacute;gicos, en especial en enfermos con compromiso del sistema inmunitario. No obstante, la afecci&oacute;n aislada del canal medular es poco frecuente. Se presenta una paciente inmunocompetente, con antecedentes de un parto reciente eut&oacute;cico con pareja estable y sin epidemiolog&iacute;a evidente para infecciones de transmisi&oacute;n sexual, que se present&oacute; a la consulta con paraparesia asim&eacute;trica con hipoestesia agregada. Mediante pruebas complementarias se lleg&oacute; al diagn&oacute;stico de neuros&iacute;filis. Se destaca la consideraci&oacute;n de esta entidad entre los diagn&oacute;sticos diferenciales del s&iacute;ndrome miel&iacute;tico, incluso en sujetos sin alteraciones de la inmunidad.Subacute myelitis as a form of presentation of syphilis in an immunocompetent patient Abstract: Neurosyphilis is associated to various clinical neurological syndromes, especially in patients with compromise of the immunological system. Nevertheless, an isolated disease of the medullar channel is rare. We present an immunocompetent patient with a background of a recent eutocic delivery, with a stable partner, and without any epidemiological evidence of sexually transmitted diseases, who consulted due to asymmetric paraparesis with aggregated hypoesthesia. Through complementary tests a diagnosis of neurosyphilis was reached. The consideration of this entity among differential diagnoses for a myelitic syndrome is emphasized, even in subjects with no immunological alterations