Validation of a Smartphone Application in the Evaluation and Treatment of Acute Stroke in a Comprehensive Stroke Center.

Background and Purpose- The increasing demand and shortage of experts to evaluate and treat acute stroke patients has led to the development of remote communication tools to aid stroke management. We aimed to evaluate the JOIN App smartphone system-a low-cost tool for rapid clinical and neuroimaging data sharing to expedite decision-making in stroke. Methods- Consecutive acute ischemic stroke patients treated at a University Hospital in Brazil from December 2014 to December 2015 were evaluated. The analysis included all patients presenting with acute ischemic stroke who underwent initial evaluation by neurology residents followed by JOIN teleconsultation with a stroke neurologist on call for management decisions. An expert panel of stroke neurologists and neuroradiologists revised all cases using a standard Picture Archiving and Communication System imaging workstation within 24 hours and analyzed the decision made with remote assistance during the emergency setting. Results- A total of 720 stroke codes were evaluated with 442 acute ischemic stroke qualifying. Seventy-eight (18%) patients were treated with intravenous thrombolysis. The main reasons for tPA (tissue-type plasminogen activator) exclusion were symptom onset >4.5 hours (n=295; 67%) and hypodense middle cerebral artery territory area >1/3 (n=31; 7%). The agreement rates between Picture Archiving and Communication System versus JOIN-based thrombolysis decisions were 100% for the stroke (unblinded) and 99.3% for the neuroradiologist (blinded) experts. The use of the application resulted in a significant reduction in the door-to-needle times across the pre- versus postimplementation periods (median, 90 [interquartile range, 75-106] versus 63 [interquartile range, 61-117] minutes; P=0.03). The rates of 90-day excellent outcomes (modified Rankin Scale, 0-1) were 51.3%; 90-day mortality, 2.6%; and symptomatic intracranial hemorrhage, 3.8%. Conclusions- The JOIN smartphone system allows rapid sharing of clinical and imaging data to facilitate decisions for stroke treatment. The remote application-based decisions seem to be as accurate as the physical presence of stroke experts and might lead to faster times to treatment. This system represents an easily implementable low-cost telemedicine solution for centers that cannot afford the full-time presence of stroke specialists.

Identification of a premature stop codon mutation in the PHGDH gene in severe Neu-Laxova syndrome-evidence for phenotypic variability.

In some cases Neu-Laxova syndrome (NLS) is linked to serine deficiency due to mutations in the phosphoglycerate dehydrogenase (PHGDH) gene. We describe the prenatal and postnatal findings in a fetus with one of the most severe NLS phenotypes described so far, caused by a homozygous nonsense mutation of PHGDH. Serial ultrasound (US) and pre- and postnatal magnetic resonance imaging (MRI) evaluations were performed. Prenatally, serial US evaluations suggested symmetric growth restriction, microcephaly, hypoplasia of the cerebellar vermis, micrognathia, hydrops, shortened limbs, arthrogryposis, and talipes equinovarus. The prenatal MRI confirmed these findings prompting a diagnosis of NLS. After birth, radiological imaging did not detect any gross bone abnormalities. DNA was extracted from fetal and parental peripheral blood, all coding exons of PHGDH were PCR-amplified and subjected to Sanger sequencing. Sequencing of PHGDH identified a homozygous premature stop codon mutation (c.1297C>T; p.Gln433*) in fetal DNA, both parents (first-cousins) being heterozygotes. Based on previous associations of mutations in this gene with a milder NLS phenotype, as well as cases of serine deficiency, these observations lend further support to a genotype-phenotype correlation between the degree of PHGDH inactivation and disease severity.

A Deep Learning-based Model for Detecting Abnormalities on Brain MR Images for Triaging: Preliminary Results from a Multisite Experience.

PURPOSE: To develop a deep learning model for detecting brain abnormalities on MR images. MATERIALS AND METHODS: In this retrospective study, a deep learning approach using T2-weighted fluid-attenuated inversion recovery images was developed to classify brain MRI findings as "likely normal" or "likely abnormal." A convolutional neural network model was trained on a large, heterogeneous dataset collected from two different continents and covering a broad panel of pathologic conditions, including neoplasms, hemorrhages, infarcts, and others. Three datasets were used. Dataset A consisted of 2839 patients, dataset B consisted of 6442 patients, and dataset C consisted of 1489 patients and was only used for testing. Datasets A and B were split into training, validation, and test sets. A total of three models were trained: model A (using only dataset A), model B (using only dataset B), and model A + B (using training datasets from A and B). All three models were tested on subsets from dataset A, dataset B, and dataset C separately. The evaluation was performed by using annotations based on the images, as well as labels based on the radiology reports. RESULTS: Model A trained on dataset A from one institution and tested on dataset C from another institution reached an F1 score of 0.72 (95% CI: 0.70, 0.74) and an area under the receiver operating characteristic curve of 0.78 (95% CI: 0.75, 0.80) when compared with findings from the radiology reports. CONCLUSION: The model shows relatively good performance for differentiating between likely normal and likely abnormal brain examination findings by using data from different institutions.Keywords: MR-Imaging, Head/Neck, Computer Applications-General (Informatics), Convolutional Neural Network (CNN), Deep Learning Algorithms, Machine Learning Algorithms© RSNA, 2021Supplemental material is available for this article.

Intrathecal enzyme replacement therapy in a patient with mucopolysaccharidosis type I and symptomatic spinal cord compression.

In mucopolysaccharidosis I, deficiency of alpha-L-iduronidase can cause spinal cord compression (SCC) due to storage of glycosaminoglycans (GAGs) within the cervical meninges. As intravenous enzyme replacement therapy (ERT) is not likely to provide enzyme across the blood-brain barrier, standard treatment for this complication is usually surgical, which has a high morbidity and mortality risk. We report on the use of intrathecal (IT) laronidase in a MPS I patient with SCC who refused the surgical treatment. Assessments were performed at baseline, with clinical and biochemical evaluations, 4-extremity somatosensory evoked potentials, 12 min walk test and MRI studies of the CNS. Changes on these parameters were evaluated after 4 IT infusions of laronidase administered monthly via lumbar puncture. To our knowledge, this was the first MPS patient who received IT ERT. No major adverse events were observed. There were no clinically significant changes in serum chemistries. CSF GAG results revealed pretreatment values slightly above normal standards: 13.3 mg/L (NV < 12 mg/L) which after IT laronidase infusions were within normal levels (10.3 mg/L). 12MWT presented a 14% improvement, with better performance on stability and gait control. Maximum voluntary ventilation showed 55.6% improvement considering the percentage of predicted (26.7% at baseline compared to 41.9%); Maximum Inspiration Pressure improved 36.6% of predicted (26.8% at baseline to 36.7%); Pulmonary diffusion improved 17.6% of predicted %. In conclusion, although the improvement observed in this case with IT laronidase should be confirmed in further patients, this procedure seems to be a safe treatment for SCC in MPS I.

Correlation of CSF flow using phase-contrast MRI with ventriculomegaly and CSF opening pressure in mucopolysaccharidoses.

BACKGROUND: Very little is known about the incidence and prevalence of hydrocephalus in patients with mucopolysaccharidoses (MPS). The biggest challenge is to distinguish communicating hydrocephalus from ventricular dilatation secondary to brain atrophy, because both conditions share common clinical and neuroradiological features. The main purpose of this study is to assess the relationship between ventriculomegaly, brain and cerebrospinal fluid (CSF) volumes, aqueductal and cervical CSF flows, and CSF opening pressure in MPS patients, and to provide potential biomarkers for abnormal CSF circulation. METHODS: Forty-three MPS patients (12 MPS I, 15 MPS II, 5 MPS III, 9 MPS IV A and 2 MPS VI) performed clinical and developmental tests, and T1, T2, FLAIR and phase-contrast magnetic resonance imaging (MRI) followed by a lumbar puncture with the CSF opening pressure assessment. For the analysis of MRI variables, we measured the brain and CSF volumes, white matter (WM) lesion load, Evans' index, third ventricle width, callosal angle, dilated perivascular spaces (PVS), craniocervical junction stenosis, aqueductal and cervical CSF stroke volumes, and CSF glycosaminoglycans concentration. RESULTS: All the scores used to assess the supratentorial ventricles enlargement and the ventricular CSF volume presented a moderate correlation with the aqueductal CSF stroke volume (ACSV). The CSF opening pressure did not correlate either with the three measures of ventriculomegaly, or the ventricular CSF volume, or with the ACSV. Dilated PVS showed a significant association with the ventriculomegaly, ventricular CSF volume and elevated ACSV. CONCLUSIONS: In MPS patients ventriculomegaly is associated with a severe phenotype, increased cognitive decline, WM lesion severity and enlarged PVS. The authors have shown that there are associations between CSF flow measurements and measurements related to CSF volumetrics. There was also an association of volumetric measurements with the degree of dilated PVS.

Correction to: Correlation of CSF flow using phase-contrast MRI with ventriculomegaly and CSF opening pressure in mucopolysaccharidoses.

After publication of the article [1], it has been brought to our attention that the full funding acknowledgement is missing from the original article.

Breast cancer mammographic diagnosis performance in a public health institution: a retrospective cohort study.

OBJECTIVES: To evaluate the quality assurance of mammography results at a reference institution for the diagnosis and treatment of breast cancer in southern Brazil, based on the BIRADS (Breast Imaging Reporting and Data System) 5th edition recommendations for auditing purposes. MATERIALS AND METHODS: Retrospective cohort and cross-sectional study with 4502 patients (9668 mammographies)) who underwent at least one or both breast mammographies throughout 2013 at a regional public hospital, linked to a federal public university. The results were followed until 31 December 2014, including true positives (TPs), true negatives (TNs), false positives (FPs), false negatives (FNs), positive predictive values (PPVs), negative predictive value (NPV), sensitivity and specificity, with a confidence interval of 95%. RESULTS: The study showed high quality assurance, particularly regarding sensitivity (90.22%) and specificity (92.31%). The overall positive predictive value (PPV) was 65.35%, and the negative predictive value (NPV) was 98.32%. The abnormal interpretation rate (recall rate) was 12.26%. CONCLUSIONS: The results are appropriate when compared to the values proposed by the BIRADS 5th edition. Additionally, the study provided self-reflection considering our radiological practice, which is essential for improvements and collaboration regarding breast cancer detection. It may stimulate better radiological practice performance and continuing education, despite possible infrastructure and facility limitations. MAIN MESSAGES: • Accurate quality performance rates are possible despite financial and governmental limitations. • Low-income institutions should develop standardised teamwork to improve radiological practice. • Regular mammography audits may help to increase the quality of public health systems.

White matter lesions in Fabry disease before and after enzyme replacement therapy: a 2-year follow-up.

PURPOSE: To report the clinical and neuroimaging, central nervous system (CNS) findings of patients with Fabry disease (FD) during 24 months of enzyme replacement therapy (ERT) with agalsidase-alpha. METHOD: Eight patients were included. Six completed 24 months of ERT. Clinical and magnetic resonance imaging (MRI) data were obtained at 0, 12 and 24 months of ERT. White matter lesions (WML) were evaluated as well as their relation to age, symptoms and neurological examination (CNS score). RESULTS: MRI was stable in 3 patients. WML and CNS score worsened in one patient, fluctuated in another, and improved in the sixth patient. In the whole series, there were 15 WML at baseline, and 19 at the 24th month. In two years, 4 lesions disappeared, whereas 8 appeared. CONCLUSION: A widespread pattern of silent WML in FD was seen. In two years, some WML appeared, and some disappeared. If these phenomena were related to the natural history, remains to be demonstrated.

Reproducibility of quantitative fiber tracking measurements in diffusion tensor imaging of frontal lobe tracts: A protocol based on the fiber dissection technique.

BACKGROUND: Diffusion tensor imaging (DTI)-based tractography is a noninvasive in vivo method for tracing white matter bundles. This raises possibilities for qualitative and quantitative assessment of the structural organization of tracts. Nevertheless, questions remain about neuroanatomical accuracy, reproducibility for clinical purposes, and accessibility of the best method for broader application. The aim of this study was to combine the fiber dissection technique and tractography to provide more pertinent insight into brain anatomy and, as a result, to test a protocol for reconstruction of six major frontal lobe tracts. METHODS: A combination of fiber dissection of formalin-fixed brain tissue after freezing (Klingler's technique) and virtual dissection (tractography) was used to develop a protocol to reconstruct major frontal tracts. Apparent diffusion coefficient (ADC), fractional anisotropy (FA), number of voxels (NVO), volume (VOL), number (NTR), and length (LEN) of tracts were evaluated to assess intra- and interobserver reproducibility. Statistical reliability was evaluated using intraclass correlation coefficients (ICCs) and the Pearson association coefficient (r). RESULTS: The virtual dissection obtained by tractography seemed to reproduce the anatomic knowledge of the white matter tracts obtained through the classic method. In reliability study, most ICC and r values corresponded at least to large correlation. The magnitude of correlation was very high (ICC 0.7-0.9) or almost perfect (ICC 0.9-1.0) for the FA and ADC measures of every tract studied. CONCLUSION: The DTI protocol proposed herein provided a reliable method for analysis of reconstructed frontal lobe tracts, especially for the FA and ADC variables.

White matter lesions in Fabry disease before and after enzyme replacement therapy: a 2-year follow-up / Lesões da substância branca na doença de Fabry antes e depois da terapia de reposição enzimática: um seguimento de 2 anos

PURPOSE: To report the clinical and neuroimaging, central nervous system (CNS) findings of patients with Fabry disease (FD) during 24 months of enzyme replacement therapy (ERT) with agalsidase-alpha. METHOD: Eight patients were included. Six completed 24 months of ERT. Clinical and magnetic resonance imaging (MRI) data were obtained at 0, 12 and 24 months of ERT. White matter lesions (WML) were evaluated as well as their relation to age, symptoms and neurological examination (CNS score). RESULTS: MRI was stable in 3 patients. WML and CNS score worsened in one patient, fluctuated in another, and improved in the sixth patient. In the whole series, there were 15 WML at baseline, and 19 at the 24th month. In two years, 4 lesions disappeared, whereas 8 appeared. CONCLUSION: A widespread pattern of silent WML in FD was seen. In two years, some WML appeared, and some disappeared. If these phenomena were related to the natural history, remains to be demonstrated.

OBJETIVO: Relatar os achados neurológicos e de imagem do sistema nervoso central (SNC), observados durante 24 meses de tratamento de reposição enzimática (ERT) com agalsidase-alfa, em pacientes com a doença de Fabry (FD). MÉTODO: 8 pacientes foram incluídos; 6 completaram 24 meses de ERT. Os dados foram obtidos aos 0, 12 e 24 meses de ERT. Lesões de substância branca (WML) foram avaliadas assim como sua relação com a idade e o exame neurológico (escore SNC). RESULTADOS: Os achados de ressonância nuclear magnética foram estáveis em 3 pacientes. As WML e o escore SNC pioraram em um caso; flutuaram em um outro caso; e melhoraram no sexto paciente. No todo, havia 15 WML antes da ERT e 19 WML depois de 24 meses de ERT. Em dois anos, 4 lesões desapareceram e 8 novas surgiram. CONCLUSÕES: Viu-se um padrão difuso de WML assintomáticas, na FD. Em dois anos, algumas WML surgiram, enquanto outras desapareceram. Resta demonstrar se esses fenômenos fazem parte da história natural da doença.