The new era of artificial intelligence in neuroradiology: current research and promising tools / A nova era da inteligência artificial em neurorradiologia: pesquisa atual e ferramentas promissoras

Abstract Radiology has a number of characteristics that make it an especially suitable medical discipline for early artificial intelligence (AI) adoption. These include having a well-established digital workflow, standardized protocols for image storage, and numerous well-defined interpretive activities. The more than 200 commercial radiologic AI-based products recently approved by the Food and Drug Administration (FDA) to assist radiologists in a number of narrow image-analysis tasks such as image enhancement, workflow triage, and quantification, corroborate this observation. However, in order to leverage AI to boost efficacy and efficiency, and to overcome substantial obstacles to widespread successful clinical use of these products, radiologists should become familiarized with the emerging applications in their particular areas of expertise. In light of this, in this article we survey the existing literature on the application of AI-based techniques in neuroradiology, focusing on conditions such as vascular diseases, epilepsy, and demyelinating and neurodegenerative conditions. We also introduce some of the algorithms behind the applications, briefly discuss a few of the challenges of generalization in the use of AI models in neuroradiology, and skate over the most relevant commercially available solutions adopted in clinical practice. If well designed, AI algorithms have the potential to radically improve radiology, strengthening image analysis, enhancing the value of quantitative imaging techniques, and mitigating diagnostic errors.

Resumo A radiologia tem uma série de características que a torna uma disciplina médica especialmente adequada à adoção precoce da inteligência artificial (IA), incluindo um fluxo de trabalho digital bem estabelecido, protocolos padronizados para armazenamento de imagens e inúmeras atividades interpretativas bem definidas. Tal adequação é corroborada pelos mais de 200 produtos radiológicos comerciais baseados em IA recentemente aprovados pelo Food and Drug Administration (FDA) para auxiliar os radiologistas em uma série de tarefas restritas de análise de imagens, como quantificação, triagem de fluxo de trabalho e aprimoramento da qualidade das imagens. Entretanto, para o aumento da eficácia e eficiência da IA, além de uma utilização clínica bem-sucedida dos produtos que utilizam essa tecnologia, os radiologistas devem estar atualizados com as aplicações em suas áreas específicas de atuação. Assim, neste artigo, pesquisamos na literatura existente aplicações baseadas em IA em neurorradiologia, mais especificamente em condições como doenças vasculares, epilepsia, condições desmielinizantes e neurodegenerativas. Também abordamos os principais algoritmos por trás de tais aplicações, discutimos alguns dos desafios na generalização no uso desses modelos e introduzimos as soluções comercialmente disponíveis mais relevantes adotadas na prática clínica. Se cautelosamente desenvolvidos, os algoritmos de IA têm o potencial de melhorar radicalmente a radiologia, aperfeiçoando a análise de imagens, aumentando o valor das técnicas de imagem quantitativas e mitigando erros de diagnóstico.

Mechanism of molecular interaction of sitagliptin with human DPP4 enzyme - New Insights.

PURPOSE: Dipeptidyl peptidase 4 (DPP4) inactivates a range of bioactive peptides. The cleavage of insulinotropic peptides and glucagon-like peptide 1 (GLP1) by DPP4 directly influences glucose homeostasis. This study aimed to describe the mode of interaction between sitagliptin (an antidiabetic drug) and human DPP4 using in silico approaches. MATERIALS AND METHODS: Docking studies were conducted using AutoDock Vina, 2D and 3D schematic drawings were obtained using PoseView and PLIP servers, and the DPP4-sitagliptin complex was visualized with Pymol software. RESULTS: The best affinity energy to form the DPP4-sitagliptin complex was E-value â€‹= â€‹- 8.1 â€‹kcal â€‹mol-1, as indicated by docking simulations. This result suggests a strong interaction. According to our observations, hydrophobic interactions involving the amino acids residues Tyr663 and Val712, hydrogen bonds (Glu203, Glu204, Tyr663, and Tyr667), π-Stacking interactions (Phe355 and Tyr667), and halogenic bonds (Arg123, Glu204, and Arg356) were prevalent in the DPP4-sitagliptin complex. Root Mean Square Deviation prediction also demonstrated that the global structure of the human DPP4 did not have a significant change in its topology, even after the formation of the DPP4-sitagliptin complex. CONCLUSION: The stable interaction between the sitagliptin ligand and the DPP4 enzyme was demonstrated through molecular docking simulations. The findings presented in this work enhance the understanding of the physicochemical properties of the sitagliptin interaction site, supporting the design of more efficient gliptin-like iDPP4 inhibitors.

Silicon mitigates iron deficiency in two energy cane cultivars by modulating physiological and nutritional mechanisms.

Introduction: Alkaline soils with iron (Fe) deficiency are found in many regions of the world, and the use of silicon (Si) can mitigate the damages caused by such deficiency. The aim of this study was to evaluate the effect of Si in mitigating a moderate deficiency of Fe in two energy cane cultivars. Methods: Two experiments were performed, one with the VX2 cultivar and the other with the VX3 cultivar of energy cane, which were cultivated in pots with sand and a nutrient solution. In both experiments, treatments followed a factorial scheme 2x2, designed based on the sufficiency and deficiency of Fe, being combined with the absence or presence of Si (2.5 mmol L-1), disposed in a randomized blocks design with six replicates. In the condition of Fe sufficiency, plants were cultivated in a solution containing 368 µmol L-1 of Fe, while plants cultivated under deficiency were initially submitted to cultivation with a 54 µmol L-1 concentration of Fe for 30 days, and later, with Fe complete omission for 60 days. The supply of Si was carried out by applying 15 fertirrigations with Si (via root and leaf) during the initial stage of seedling development, and after transplanting, the nutrient solution was added daily (via root). Results and discussion: Both cultivars of energy cane were sensitive to Fe deficiency in the absence of Si, impairing its growth by causing stress and pigment degradation, thus reducing the photosynthesis efficiency. The supply of Si mitigated the damages caused by Fe deficiency in both cultivars, by increasing Fe accumulation in new and intermediate leaves, stem, and roots in the VX2 cultivar, and in new, intermediate, and old leaves and stem in the VX3 cultivar, which in turn reduced stress and favored both the nutritional and photosynthesis efficiency, while increasing the dry matter production. Si by modulating physiological and nutritional mechanisms, mitigates Fe deficiency in two energy cane cultivars. It was concluded that Si can be used as a strategy to improve growth and nutrition of energy cane in environments that are susceptible to Fe deficiency.

"Bunch of acai berries sign": a new radiological sign in patients with CNS involvement in Chagas disease.

Chagas disease is an infection caused by Trypanosoma cruzi, a parasite endemic in Latin America. Acute involvement of the CNS by Chagas has been considered rare, but presumed reactivation of chronic disease in immunosuppressed patients has been the subject of recent reports. Our objective is to describe the clinical and imaging characteristics of four patients with Chagas disease and CNS involvement, and the patients had to have available MRI and a diagnosis confirmed by biopsy. The imaging findings were similar, highlighting the presence of focal cerebral lesions with hypointensity on T2-WI, and these lesions assume a "bunch of acai berries appearance", a fruit involved in the transmission of T. cruzi. The post Gd T1-WI shows punctate enhancement. Knowledge of this pattern may be crucial to recognize this disease in immunocompromised patients from endemic areas.

Impact of inbreeding and genetic parameter estimates for seminal traits in Lusitano horses.

The objectives of this study were to establish baseline information for seminal traits in Lusitano stallions, to assess the impact of inbreeding, interval between collections and age on semen quality during the breeding and non-breeding seasons, and to estimate the corresponding genetic parameters. A total of 2129 ejaculates by 146 Lusitano stallions used for artificial insemination, obtained from four equine reproduction centers distributed throughout Portugal, over a period of 14 years (2008-2021), were included in the study. The seminal traits analyzed, and the corresponding means and standard deviations, were gel-free volume (56.95 ± 28.76 mL), concentration (186.48 ± 104.68 × 106), motility (64.1 ± 16.9%), total number of spermatozoa (TNS) (9.271 ± 4.956 × 109) and total number of motile spermatozoa per ejaculate (TNMS) (5.897 ± 3.587 × 109). These results are in the normal range of values described for other breeds. In the stallions analyzed, the mean value for the inbreeding coefficient was 7.93 ± 5.29%, and for age it was 12.70 ± 6.83 years. A significant decline in sperm concentration, motility, TNS, and TNMS was observed as inbreeding increased. The season also influenced sperm concentration, motility, TNS and TNMS, with the highest values observed during the breeding season. When considering the impact of age on Lusitano seminal parameters, results showed a nonlinear relationship, with a positive effect until 18 years of age for volume, motility, TNS and TNMS and a negative effect after this age, with a slow decrease. However, age had a markedly negative effect on sperm concentration. The interval between semen collections only affected (P < 0.05) sperm motility, with a regression coefficient of +1.89 ± 2.17% per additional day. Genetic parameters were estimated with an Animal Model, and the estimated heritability (repeatability) was 0.27 (0.35) for volume, 0.02 (0.38) for sperm concentration, 0.24 (0.44) for motility, 0.29 (0.39) for TNS and 0.41 (0.41) for TNMS. These results suggest that it is possible to improve semen quality by selection and that the properties of semen produced by a stallion tend to remain consistent throughout its lifetime. Furthermore, the impact of inbreeding should be taken into consideration when selecting Lusitano stallions for fertility.

Case report: Long term follow-up of a large unilateral epididymal cyst in a stallion used for teaching: Is this condition associated with infertility?

A 30-year-old Lusitano stallion presented with an enlarged right epididymis. The ultrasound scan revealed a cyst-like formation and the histopathological examination was compatible with epididymal cyst located at the body/tail transition, epididymal spermatocele and sperm granuloma and epididymitis. However, these conditions did not seem to affect the animal's reproductive performance, nor did the semen parameters analyzed over the 8 years after the diagnosis show significant changes. Nevertheless, since the ejaculate contains mostly sperm cells from the tail of the epididymis, where fertile spermatozoa are stored until ejaculated, a deep knowledge of the different conditions that can affect this organ is of the utmost importance.

Intracranial vessel wall magnetic resonance imaging features of infectious vasculitis.

Vasculitis is a complication of several infectious diseases affecting the central nervous system, which may result in ischemic and/or hemorrhagic stroke, transient ischemic attack, and aneurysm formation. The infectious agent may directly infect the endothelium, causing vasculitis, or indirectly affect the vessel wall through an immunological mechanism. The clinical manifestations of these complications usually overlap with those of non-infectious vascular diseases, making diagnosis challenging. Intracranial vessel wall magnetic resonance imaging (VWI) enables the evaluation of the vessel wall and the diseases that affect it, providing diagnostic data beyond luminal changes and enabling the identification of inflammatory changes in cerebral vasculitis. This technique demonstrates concentric vessel wall thickening and gadolinium enhancement, associated or not with adjacent brain parenchymal enhancement, in patients with vasculitis of any origin. It permits the detection of early alterations, even before a stenosis occurs. In this article, we review the intracranial vessel wall imaging features of infectious vasculitis of bacterial, viral, and fungal etiologies.

Reduced cardiovascular risk score following bilateral cataract phacoemulsification surgery: A retrospective observational cohort study.

OBJECTIVE: To assess the cardiovascular risk (CV risk) change following bilateral phacoemulsification cataract surgery. METHODS: We performed a retrospective observation cohort study on 112 selected patients who underwent uncomplicated bilateral cataract surgery at Centro Hospitalar de Entre o Douro e Vouga (CHEDV) between 2018 and 2019. This patient cohort was further subdivided in 2 different groups: Good VA - no to mild visual impairment, ≤0.48 LogMAR; Bad VA - moderate to severe visual impairment, >0.48 LogMAR. We compared the changes in the CV risk score components in our patient cohort and between subgroups Good VA and Bad VA, before and after surgery, using paired t-test or Wilcoxon rank-sum test, and repeated measures ANOVA with Tukey post-hoc tests, respectively. Visual Acuity (VA) before and after surgery was correlated with the patients' CV risk score. At last, linear regression models were built to explain changes in CV risk variables considering the change in VA. RESULTS: Cataract surgery resulted in improved VA. Notably, following surgery our patient cohort showed reduced low-density lipoprotein (LDL) levels after surgery, from 111.17±36.26 mg/dL to 104.22±37.53 mg/dL, and reduced systolic arterial pressure (SAP), from 139.1±15.0 mmHg to 133.7±12.0 mmHg. Ultimately, this translated to an improved CV risk score within 6 months of cataract surgery, from 17.39±11.44% to 16.51±11.27%. Of note, these improvements were mostly present in the Bad VA group of patients, where baseline VA and incidence of dyslipidemia were worse. CONCLUSION: Our results suggest that phacoemulsification cataract surgery may be an important tool in addressing CV risk.

Chronic Coronary Syndrome: Medical Therapy or Myocardial Revascularization?

Abstract The best therapeutic strategy for chronic coronary syndrome (CCS) is still controversial. The lack of contemporaneity of medical treatment in many randomized clinical trials prior to the large-scale use of statins, antiplatelet agents, anti-diabetic drugs with cardiovascular protection, and changes in life habits with well-established goals limits the applicability of such studies in current clinical practice. Medical treatment is the only therapeutic option capable of reducing atherosclerotic damage and, therefore, of acting effectively in preventing the progression of this disease. The purpose of this brief review is to critically analyze the main contemporary studies that confront medical treatment with myocardial revascularization in CCS.

Extra-pituitary midline structural abnormalities associated with ectopic posterior pituitary detected on a new rapid MRI protocol (FAST1.2)

ABSTRACT Objective: Test if the MRI FAST1.2 protocol can detect extra-pituitary midline structural brain abnormalities in patients with ectopic posterior pituitary (EPP), and highlighting their radiological-laboratory correlations. Subjects and methods: Cross-sectional study of patients with EPP and control group. All individuals were submitted to FAST1.2, which combines the FAST1 protocol developed by our group with 3D T2DRIVE imaging. Results: We evaluated 36 individuals with EPP and 78 as control group. Pituitary stalk (PS) was identified in 7/36 patients in EPP group by FAST1, and in 24/36 patients in FAST1.2 (p < 0.001). FAST1 failed to detect PS in one individual in the control group, while the FAST1.2 defined the PS in all individuals. In EPP group, eleven had interhypothalamic adhesion (IHA), three septo-optic dysplasia, and one cerebellar malformation. We didn't observe higher frequency of panhypopituitarism or developmental delay in patients with IHA. In control group, three had pars intermedia cysts, one hydrocephalus, and one hypothalamic hamartoma. Conclusions: FAST1.2 allows confident recognition of midline structural abnormalities, including the pituitary stalk and IHA, thereby making MRI acquisition faster and with no need for contrast administration. IHA could be associated with defects in neuronal migration, as occur in patients with EPP, with no clinical significance.

Action of silicon on the activity of antioxidant enzymes and on physiological mechanisms mitigates water deficit in sugarcane and energy cane plants.

Production of sugarcane and more recently of energy cane strengthen renewable bioenergy production capacity. However, droughts resulting from climate change have limited the production of these crops. One of the strategies to attenuate water deficit damage in these crops is the use of silicate, which contributes to plant physiology. This strategy is likely to increase water use efficiency, thus promoting crop sustainability. Notwithstanding, studies on this issue are still incipient. This study assesses whether Si applied via fertigation and foliar spraying in the seedling production phase and as a complement after seedling transplanting to the soil is efficient in attenuating water deficit in sugarcane and energy cane. The study further elucidates physiological and biochemical mechanisms involved in this process. For this, the authors conducted two experiments: one with sugarcane and the other with energy cane. Treatments were arranged in randomized blocks with 5 replications, in a 2 × 2 factorial scheme. Factors consisted of the absence (-Si) and presence of Si (+ Si) applied via fertigation and foliar spraying; and two water regimes: 70% (without water deficit) and 30% (severe water deficit) of the soil water retention capacity. Silicon was supplied during the formation phase of presprouted seedlings and during the transplanting of seedlings to pots filled with samples of Entisol (Quartzipsamment). In these pots, water regimes were induced from 7 to 160 days after transplanting. Severe water deficit reduced the water content and water potential of plants. This situation induced oxidative stress and impaired gas exchange and photosynthetic water use efficiency, reducing plant growth. Silicon supply via fertigation in association with foliar spraying in the seedling formation phase with complementation after transplanting was efficient in increasing Si accumulation in the plants. Silicon was effective in attenuating severe water deficit damage up to initial culm formation through mechanisms that maintain water and physiological balance by favoring the antioxidant defense system in sugarcane and energy cane plants.

Extra-pituitary midline structural abnormalities associated with ectopic posterior pituitary detected on a new rapid MRI protocol (FAST1.2).

Objective: Test if the MRI FAST1.2 protocol can detect extra-pituitary midline structural brain abnormalities in patients with ectopic posterior pituitary (EPP), and highlighting their radiological-laboratory correlations. Subjects and methods: Cross-sectional study of patients with EPP and control group. All individuals were submitted to FAST1.2, which combines the FAST1 protocol developed by our group with 3D T2DRIVE imaging. Results: We evaluated 36 individuals with EPP and 78 as control group. Pituitary stalk (PS) was identified in 7/36 patients in EPP group by FAST1, and in 24/36 patients in FAST1.2 (p < 0.001). FAST1 failed to detect PS in one individual in the control group, while the FAST1.2 defined the PS in all individuals. In EPP group, eleven had interhypothalamic adhesion (IHA), three septo-optic dysplasia, and one cerebellar malformation. We didn't observe higher frequency of panhypopituitarism or developmental delay in patients with IHA. In control group, three had pars intermedia cysts, one hydrocephalus, and one hypothalamic hamartoma. Conclusion: FAST1.2 allows confident recognition of midline structural abnormalities, including the pituitary stalk and IHA, thereby making MRI acquisition faster and with no need for contrast administration. IHA could be associated with defects in neuronal migration, as occur in patients with EPP, with no clinical significance.

Adding T2-Weighted Images to FAST1 Protocol to Evaluate the Anatomy of the Hypothalamic-Pituitary Region.

INTRODUCTION: Ectopic posterior pituitary (EPP) is a malformation of the hypothalamic-pituitary region presented as a spectrum from isolated growth hormone deficiency (GHD) to multiple pituitary hormone deficiencies (MPHDs). Our goal was to establish whether the FAST1.2 protocol, which combines the FAST1 protocol with 3D-T2 DRIVE images, could identify the pituitary stalk (PS) and the regional anatomy more accurately. METHODS: A retrospective study of 36 individuals with EPP and hypopituitarism and a control group of 78 individuals with eutopic posterior pituitary was conducted. All individuals were submitted to FAST1.2. The position and size of the pituitary lobes were described, and the presence/absence of the PS was confirmed. RESULTS: FAST1 identified the PS in 19% of individuals with EPP, while FAST1.2 identified the PS in 67% (p < 0.001). In the FAST1.2 protocol, the PS was visible in all control individuals. All EPP patients with isolated GHD had visible PS in FAST1.2, while only 58.6% of MPHD cases had visible PS. The size of the anterior lobe and the anteroposterior length of the posterior pituitary were smaller in the EPP group versus controls (p < 0.001). We noticed a reduced anterior pituitary lobe in both diameters in MPHD patients (p < 0.05). Six patients acquired new pituitary hormone deficiencies not recognized at the time of MRI; in this group, only 1 patient had a PS not visible in FAST1.2. DISCUSSION/CONCLUSION: The FAST1.2 protocol could prevent the misdiagnosis of idiopathic GHD in patients with short stature and could also be important in the progression to MPHD. The PS could be considered a predictor of hypopituitarism, but its use as an isolated indicator for the progression to MPHD is not recommended. Our results reinforce the use of the size of the anterior lobe as a predictor of hypopituitarism and a possible predictor of the degree of pituitary insufficiency. The FAST1.2 protocol could be used as an alternative to gadolinium administration, as a cheaper and faster method, while eliminating the potential risks associated with the administration of contrast media.

Neurological imaging findings in hospitalized COVID-19 patients: a retrospective observational study in two Brazilian reference centers / Achados de neuroimagem em pacientes hospitalizados por COVID-19: um estudo retrospectivo e observacional em dois serviços brasileiros de referência

ABSTRACT Background: A variety of neurological manifestations have been attributed to COVID-19. Objective: To investigate the occurrence of neurological symptoms and neuroimaging findings in patients hospitalized in two Brazilian reference centers. Methods: We performed a retrospective cohort study of patients who had laboratory-confirmed COVID-19 presenting in two hospitals in Brazil between March 4 and July 7, 2020, who underwent brain imaging. Results: We recorded 1,359 patients with laboratory-confirmed COVID-19. Brain imaging was performed in 250 (18.4%) patients with neurological symptoms, and nine of them (3.6%) had acute or subacute ischemic stroke neuroimaging findings. Six of the nine patients initially presented with respiratory symptoms while the other three patients presented to the emergency room with acute stroke signs. Conclusions: We described the neuroimaging findings of patients infected with COVID-19 who presented with neurological symptoms in two major hospitals in Brazil. We reinforce the importance of being aware of cerebrovascular complications, both in severe hospitalized patients and in patients who present to the emergency room with acute neurological symptoms, even in the elderly.

RESUMO Introdução: Diversas manifestações neurológicas têm sido atribuídas à COVID-19. Objetivo: Investigar a ocorrência de sintomas neurológicos e achados de neuroimagem em pacientes internados em dois centros de referência brasileiros. Métodos: Estudo retrospectivo que avaliou pacientes internados em dois hospitais no Brasil entre 4 de março e 7 de julho de 2020, com confirmação laboratorial de infecção pelo COVID-19 e que foram submetidos a tomografia computadorizada ou ressonância magnética do crânio em razão de sintomas neurológicos. Resultados: Obtivemos 1.359 pacientes com confirmação laboratorial de infecção pelo COVID-19. Deles, 250 (18,4%) apresentaram sintomas neurológicos e foram submetidos a exames de imagem do crânio e nove (3,6%) demonstraram achados de neuroimagem compatíveis com acidente vascular cerebral (AVC) isquêmico agudo ou subagudo. Em seis dos nove pacientes, observaram-se inicialmente tosse e dispneia graves, enquanto outros três chegaram ao pronto-socorro com sinais de AVC agudo. Conclusões: Foram descritos os achados de neuroimagem em pacientes infectados com COVID-19 em dois grandes centros de referência brasileiros. Reforçamos a importância de estar atento aos quadros neurológicos, especialmente de AVC, tanto em pacientes graves hospitalizados quanto em pacientes que chegam ao pronto-socorro com sintomas neurológicos agudos, mesmo em idosos.

Predictive Value of Myocardial injury in Patients with COVID-19 Admitted to a Quaternary Hospital in the City of Rio de Janeiro

Abstract Background In Brazil the factors involved in the risk of death in patients with COVID-19 have not been well established. Objective To analyze whether elevations of high-sensitivity troponin I (hTnI) levels influence the mortality of patients with COVID-19. Methods Clinical and laboratory characteristics of hospitalized patients with COVID-19 were collected upon hospital admission. Univariate and binary logistic regression analyzes were performed to assess the factors that influence mortality. P-value<0.05 was considered significant. Results This study analyzed192 patients who received hospital admission between March 16 and June 2, 2020 and who were discharged or died by July 2, 2020. The mean age was 70±15 years, 80 (41.7%) of whom were women. In comparison to those who were discharged, the 54 (28.1%) who died were older (79±12 vs 66±15years; P=0.004), and with a higher Charlson´s index (5±2 vs 3±2; P=0.027). More patients, aged≥60years (P <0.0001), Charlson´s index>1 (P=0.004), lung injury>50% in chest computed tomography (P=0.011), with previous coronary artery disease (P=0.037), hypertension (P=0.033), stroke (P=0.008), heart failure (P=0.002), lymphocytopenia (P=0.024), high D-dimer (P=0.024), high INR (P=0.003), hTnI (P<0.0001), high creatinine (P<0.0001), invasive mechanical ventilation (P<0.0001), renal replacement therapy (P<0.0001), vasoactive amine (P<0.0001), and transfer to the ICU (P=0.001), died when compared to those who were discharged. In logistic regression analysis, elevated hTnI levels (OR=9.504; 95% CI=1.281-70.528; P=0.028) upon admission, and the need for mechanical ventilation during hospitalization (OR=46.691; 95% CI=2.360-923.706; P=0.012) increased the chance of in-hospital mortality. Conclusion This study suggests that in COVID-19 disease, myocardial injury upon hospital admission is a harbinger of poor prognosis.