Diffuse Abnormalities Research Articles

A unified global tractography framework for automatic visual pathway reconstruction.

The human visual pathway starts from the retina, passes through the retinogeniculate visual pathway, the optic radiation, and finally connects to the primary visual cortex. Diffusion MRI tractography is the only technology that can noninvasively reconstruct the visual pathway. However, complete and accurate visual pathway reconstruction is challenging because of the skull base environment and complex fiber geometries. Specifically, the optic nerve within the complex skull base environment can cause abnormal diffusion signals. The crossing and fanning fibers at the optic chiasm, and a sharp turn of Meyer's loop at the optic radiation, contribute to complex fiber geometries of the visual pathway. A fiber trajectory distribution (FTD) function-based tractography method of our previous work and several high sensitivity tractography methods can reveal these complex fiber geometries, but are accompanied by false-positive fibers. Thus, the related studies of the visual pathway mostly applied the expert region of interest selection strategy. However, interobserver variability is an issue in reconstructing an accurate visual pathway. In this paper, we propose a unified global tractography framework to automatically reconstruct the visual pathway. We first extend the FTD function to a high-order streamline differential equation for global trajectory estimation. At the global level, the tractography process is simplified as the estimation of global trajectory distribution coefficients by minimizing the cost between trajectory distribution and the selected directions under the prior guidance by introducing the tractography template as anatomic priors. Furthermore, we use a deep learning-based method and tractography template prior information to automatically generate the mask for tractography. The experimental results demonstrate that our proposed method can successfully reconstruct the visual pathway with high accuracy.

Calcium Alginate Production through Forward Osmosis with Reverse Solute Diffusion and Mechanism Analysis

Calcium alginate (Ca-Alg) is a novel target product for recovering alginate from aerobic granular sludge. A novel Ca-Alg production method was proposed herein where Ca-Alg was formed in a sodium alginate (SA) feed solution (FS) and concentrated via forward osmosis (FO) with Ca2+ reverse osmosis using a draw solution of CaCl2. An abnormal reverse solute diffusion was observed, with the average reverse solute flux (RSF) decreasing with increasing CaCl2 concentrations, while the average RSF increased with increasing alginate concentrations. The RSF of Ca2+ in FS decreased continuously as the FO progressed, using 1.0 g/L SA as the FS, while it increased initially and later decreased using 2.0 and 3.0 g/L SA as the FS. These results were attributed to the Ca-Alg recovery production (CARP) formed on the FO membrane surface on the feed side, and the percentage of Ca2+ in CARP to total Ca2+ reverse osmosis reached 36.28%. Scanning electron microscopy and energy dispersive spectroscopy also verified CARP existence and its Ca2+ content. The thin film composite FO membrane with a supporting polysulfone electrospinning nanofiber membrane layer showed high water flux and RSF of Ca2+, which was proposed as a novel FO membrane for Ca-Alg production via the FO process with Ca2+ reverse diffusion. Four mechanisms including molecular sieve role, electrification of colloids, osmotic pressure of ions in CARP, and FO membrane structure were proposed to control the Ca-Alg production. Thus, the results provide further insights into Ca-Alg production via FO along with Ca2+ reverse osmosis.

Cartilage grafts mimicking cholesteatoma recurrence on diffusion-weighted magnetic resonance imaging: a case series.

Cholesteatomas present a high risk for residual and recurrent disease, and the surveillance of post-operative patients can be challenging. Diffusion-weighted magnetic resonance imaging is becoming the preferred method for investigating recidivism; however, false positive imaging findings increase the risk of patients undergoing unnecessary second look surgery. This study reports two patients with false positive diffusion restriction associated with cartilage grafts that mimicked cholesteatoma and resulted in second look surgery with no disease found at operation. This study also discusses the related medical literature, including potential causes of abnormal diffusion restriction and methods to negate this. Caution should be exercised when considering second look surgery in the presence of a cartilage graft and a high confidence of disease clearance. A multi-disciplinary approach is recommended for the operating surgeon to review the images with a radiologist.

Fronto-striatal damage may contribute to resistance to fatigue-lowering medications in multiple sclerosis.

Commonly used fatigue-lowering medications have not been proven effective in treating multiple sclerosis (MS)-related fatigue. A neuroanatomical basis for treatment-resistant fatigue in MS has not been explored. The aim of this study was to investigate the association between brain diffusion abnormality patterns and resistance to fatigue-lowering treatment. Retrospective patient stratification: 1. treatment-resistant (n = 22) received anti-fatigue and/or anti-depressant and/or anxiolytic medication and the latest two Modified Fatigue Impact Scale (MFIS) score≥38; 2. responder (n = 16): received anti-fatigue and/or antidepressant and/or anxiolytic medication while the latest MFIS was <38, and minimum one previous MFIS was ≥38; 3. non-treated never-fatigued (n = 26): received none of the above-mentioned medications and MFIS was always<38 (over minimum four years assessed with MFIS every 1-2 years). 3T brain MRI was used to perform a cross-sectional voxel-wise comparison of fractional anisotropy (FA) between the groups. Treatment-resistant versus responder patients showed more extensive brain damage (ie, lower FA) favoring the fronto-striatal pathways. Both groups showed more widespread brain damage than non-treated never-fatigued patients. A mean fronto-striatal FA value of 0.26 could perfectly predict response to modafinil/armodafinil. Fronto-striatal damage may play a role in the development of resistance to fatigue-lowering treatment. Fronto-striatal FA may serve as a biomarker to predict response to fatigue-lowering medications in MS.

Hepatobiliary and Pancreatic: Hepatic mass discovered incidentally with telangiectasia.

A 48-year-old woman with no history of alcohol use or medical history was referred to our hospital for abnormal endoscopic and liver sonography findings collected at another hospital. An gastric angiodysplasia (telangiectasia) on endoscopy and two suspicious liver echogenic masses in hepatic S4 and S6 were detected. Her laboratory tests, including liver function tests and tumor markers, were within the normal ranges and the viral markers were negative. Autoimmune antibodies related to autoimmune hepatitis were negative. As she had a severe allergic reaction to the computed tomography (CT) contrast agent, she underwent liver magnetic resonance imaging (MRI) for further evaluation. The liver MRI revealed dozens of hypervascular nodules of various sizes with a central scar and diffuse vascular abnormalities with peripheral vascular obliteration (Fig. 1a). She had experienced intermittent bleeding of the tongue and several telangiectasias were observed on her tongue (Fig. 1b). The differential diagnoses included hepatocellular adenoma and multiple focal nodular hyperplasia (FNH) syndrome with primary or secondary hepatic vascular abnormalities. Osler-Weber-Rendu disease (hereditary hemorrhagic telangiectasia [HHT]) was also possible considering the diffuse vascular abnormalities in the liver and the telangiectasia on the tongue. The pathology report based on the targeted liver biopsy described a hepatocellular nodular lesion composed of bland looking hepatocytes with sinusoidal dilatation and abnormal vessels, suggesting FNH or hepatocellular adenoma; however, immunohistochemical staining did not confirm either disease (Fig. 2). On the annual MRI follow up, innumerable hypervascular nodules, irregular heterogeneous enhancement of the liver (Fig. 3a), and diffuse vascular abnormalities with peripheral vascular obliteration (Fig. 3b) were the major findings, with no changes seen from the previous exam. Given that the pathology report did not definitively diagnose hepatocellular adenoma or multiple FNH syndrome, a hepatic vascular disorder such as HHT was considered in the differential diagnosis and genetic testing was performed. HHT is an autosomal dominant inherited disorder that affects the vasculature and is considered a rare disease, with a prevalence of 1 in 5000 or 1 in 10 000 births. The pathogenesis of HHT is a heterozygous mutation in the endoglin (ENG) gene or the activin receptor-like kinase type 1 gene, both of which are associated with the transforming growth factor-β superfamily signaling pathway, expressed mostly in the vascular endothelium. As 97% of patients with definite HHT carry a mutation in one of three genes, including ENG, a mutation in a locus mapped to chromosome 5, or an activin receptor-like kinase-1 (ACVRL1), we consulted the genetics department to evaluate the patient for HHT. HHT has traditionally been diagnosed based on clinical features (the Curacao criteria), but can now also be diagnosed by genetic testing. HHT is clinically suspected if two of the four Curacao criteria are met (family history of the disease, hemorrhage, telangiectasia, and visceral involvement) and definite if more than three of the criteria are met. The presence of intrahepatic shunts, disseminated intraparenchymal telangiectases, and other vascular lesions are the typical findings of hepatic involvement. In this patient, three (epistaxis, telangiectasia, and visceral involvement) of the four Curacao criteria were satisfied, leading to a definite diagnosis of HHT. Next-generation sequencing (NGS) panel performed also showed heterozygous mutation of the ACVRL1 (ALK1) gene, which is consistent with HHT type 2.

Neuroimaging mechanisms in short-term heroin- and methamphetamine-abstinent users: Similarities and differences

Heroin and methamphetamine cause great damage to individuals and society. However, numerous withdrawal mechanisms remain unidentified. In this study, 19 heroin short-term abstinent (HSTA) patients, 20 methamphetamine short-term abstinent (MSTA) patients, and 27 healthy controls (HCs) were scanned using multimodal magnetic resonance imaging. Degraded nodes of fiber tracts were identified using automated fiber quantification. Voxel- and surface-based morphometric measurements were performed to determine the gray matter volume and cortical thickness. The MSTA and HSTA groups had abnormal diffusion metrics in a variety of bilateral corticospinal tract (CST) and left superior longitudinal tract (SLT) nodes compared with the HC group. The MSTA patients reported more severely disrupted diffusion metrics in certain nodes of the bilateral anterior thalamic radiation and left inferior fronto-occipital tract than the HSTA patients. The MSTA and HSTA groups exhibited identical cortical damage in the fusiform and superior temporal gyri, as well as in the superior frontal gyrus, posterior cerebellum, and precentral gyrus. Extensive differences in gray matter lesions were observed between the MSTA and HSTA groups. Neuroimaging mechanisms of short-term abstinence may aid in the development of rehabilitation strategies.

Abnormal brain diffusivity in participants with persistent neuropsychiatric symptoms after COVID-19.

We aimed to compare brain white matter integrity in participants with post-COVID-19 conditions (PCC) and healthy controls. We compared cognitive performance (NIH Toolbox®), psychiatric symptoms and diffusion tensor imaging (DTI) metrics between 23 PCC participants and 24 controls. Fractional anisotropy (FA), axial (AD), radial (RD), and mean (MD) diffusivities were measured in 9 white matter tracts and 6 subcortical regions using MRICloud. Compared to controls, PCC had similar cognitive performance, but greater psychiatric symptoms and perceived stress, as well as higher FA and lower diffusivities in multiple white matter tracts (ANCOVA-p-values≤0.001-0.048). Amongst women, PCC had higher left amygdala-MD than controls (sex-by-PCC p=0.006). Regardless of COVID-19 history, higher sagittal strata-FA predicted greater fatigue (r=0.48-0.52, p<0.001) in all participants, and higher left amygdala-MD predicted greater fatigue (r=0.61, p<0.001) and anxiety (r=0.69, p<0.001) in women, and higher perceived stress (r=0.45, p=0.002) for all participants. Microstructural abnormalities are evident in PCC participants averaged six months after COVID-19. The restricted diffusivity (with reduced MD) and higher FA suggest enhanced myelination or increased magnetic susceptibility from iron deposition, as seen in stress conditions. The higher amygdala-MD in female PCC suggests persistent neuroinflammation, which might contribute to their fatigue, anxiety, and perceived stress.

BAL Proteomic Signature of Lung Adenocarcinoma in IPF Patients and Its Transposition in Serum Samples for Less Invasive Diagnostic Procedures.

Idiopathic pulmonary fibrosis (IPF) is a form of chronic and irreversible fibrosing interstitial pneumonia of unknown etiology. Although antifibrotic treatments have shown a reduction of lung function decline and a slow disease progression, IPF is characterize by a very high mortality. Emerging evidence suggests that IPF increases the risk of lung carcinogenesis. Both diseases show similarities in terms of risk factors, such as history of smoking, concomitant emphysema, and viral infections, besides sharing similar pathogenic pathways. Lung cancer (LC) diagnosis is often difficult in IPF patients because of the diffuse lung injuries and abnormalities due to the underlying fibrosis. This is reflected in the lack of optimal therapeutic strategies for patients with both diseases. For this purpose, we performed a proteomic study on bronchoalveolar lavage fluid (BALF) samples from IPF, LC associated with IPF (LC-IPF) patients, and healthy controls (CTRL). Molecular pathways involved in inflammation, immune response, lipid metabolism, and cell adhesion were found for the dysregulated proteins in LC-IPF, such as TTHY, APOA1, S10A9, RET4, GDIR1, and PROF1. The correlation test revealed a relationship between inflammation- and lipid metabolism-related proteins. PROF1 and S10A9, related to inflammation, were up-regulated in LC-IPF BAL and serum, while APOA1 and APOE linked to lipid metabolism, were highly abundant in IPF BAL and low abundant in IPF serum. Given the properties of cytokine/adipokine of the nicotinamide phosphoribosyltransferase, we also evaluated its serum abundance, highlighting its down-regulation in LC-IPF. Our retrospective analyses of BAL samples extrapolated some potential biomarkers of LC-IPF useful to improve the management of these contemporary pathologies. Their differential abundance in serum samples permits the measurement of these potential biomarkers with a less invasive procedure.

Risk factors for clinically significant diffuse parenchymal lung abnormalities persisting after severe COVID-19 pneumonia.

The risk factors for clinically significant diffuse parenchymal lung abnormalities (CS-DPLA) persisting after severe coronavirus disease 2019 (COVID-19) pneumonia remain unclear. The present study was conducted to assess whether COVID-19 severity and other parameters are associated with CS-DPLA. The study participants included patients who recovered after acute severe COVID-19 and presented with CS-DPLA at two or six month follow up and control group (without CS-DPLA). Adults volunteers without any acute illness, chronic respiratory illness and without a history of severe COVID-19 were included as healthy controls for the biomarker study. The CS-DPLA was identified as a multidimensional entity involving clinical, radiological and physiological pulmonary abnormalities. The primary exposure was the neutrophil-lymphocyte ratio (NLR). Recorded confounders included age, sex, peak lactate dehydrogenase (LDH), advanced respiratory support (ARS), length of hospital stay (LOS) and others; associations were analyzed using logistic regression. The baseline serum levels of surfactant protein D, cancer antigen 15-3 and transforming growth factor-β (TGF-β) were also compared among cases, controls and healthy volunteers. We identified 91/160 (56.9%) and 42/144 (29.2%) participants with CS-DPLA at two and six months, respectively. Univariate analyses revealed associations of NLR, peak LDH, ARS and LOS with CS-DPLA at two months and of NLR and LOS at six months. The NLR was not independently associated with CS-DPLA at either visit. Only LOS independently predicted CS-DPLA at two months [adjusted odds ratios (aOR) (95% confidence interval [CI]), 1.16 (1.07-1.25); P<0.001] and six months [aOR (95% CI) and 1.07 (1.01-1.12); P=0.01]. Participants with CS-DPLA at six months had higher baseline serum TGF-β levels than healthy volunteers. Longer hospital stay was observed to be the only independent predictor of CS-DPLA six months after severe COVID-19. Serum TGF-β should be evaluated further as a biomarker.

Особенности дифференциальной диагностики нарушений обмена углеводов и жирных кислот у детей

The purpose of presenting clinical observations is to demonstrate the differential diagnosis of metabolic diseases using clinical cases of carbohydrate and fat metabolism disorders as examples. Main points. Patient observation, analysis of the case histories of two patients with Hirke's disease and long-chain acyl-CoA fatty acid dehydrogenase deficiency, LCHADD, OMIM#609016). Patients aged 5 and 10 months were admitted to the clinic in a severe condition due to the lack of effect of outpatient treatment. Both children had hepatomegaly, with fibrosis stage F-0 according to METAVIR. In Hirke's disease there were diffuse changes in the liver, increased size of the kidneys, changes in their parenchyma, in the case of fat metabolism pathology the liver echostructure was homogeneous and uniform. The girl had diffuse repolarization abnormalities on ECG, the boy had delayed conduction along the right Giss bundle. Neurosonography showed residual posthypoxic changes in the girl (history of cerebral edema at the onset of the disease, sepsis, infectious-toxic shock, glycogenosis type 1a), venous dyscirculation. Both children's condition was stable and severe in the course of treatment. Conclusion. Peculiarities of the diseases caused by metabolic disorders are polymorphism of clinical manifestations, which causes difficulties of diagnostic search as well as timely selection of effective therapy. Key words: Hirke's disease, deficiency of long-chain 3-hydroxy acyl-CoA fatty acid dehydrogenase

Prenatal tobacco smoke exposure and risk of brain abnormalities on magnetic resonance imaging at term in infants born very preterm

Prenatal tobacco smoke exposure and preterm birth are associated with abnormal brain and neurodevelopmental outcomes in infants. Studies that can disentangle indirect mediating effects from direct effects of prenatal tobacco smoke exposure on sensitive early brain magnetic resonance imaging biomarkers in very preterm infants are needed. This study aimed to determine whether prenatal tobacco smoke exposure in preterm infants posed any direct effects on magnetic resonance imaging-determined global brain abnormality score and secondary measures of brain abnormalities after removing any indirect mediating effects of preterm birth on neurostructural outcomes. We examined brain magnetic resonance imaging findings collected at 39 to 44 weeks postmenstrual age from a prospective cohort of 395 infants born very preterm (gestational age of ≤32 weeks). The primary outcome was global brain abnormality score, and the secondary outcomes were global efficiency of structural connectome, diffuse white matter abnormality volume, total brain tissue volume, total gray and white matter volumes, and cerebellar volume. Maternal reports of smoking during pregnancy were obtained. We performed multivariable linear regression analyses to examine the association between prenatal tobacco smoke exposure and our magnetic resonance imaging outcomes, controlling for prospectively collected confounders. Moreover, we performed a mediation analysis to estimate the direct effects of prenatal tobacco smoke exposure on brain abnormalities and any indirect effects through preterm birth. Overall, 12.6% of infants had prenatal tobacco smoke exposure. Infants with prenatal tobacco smoke exposure had a higher median global brain abnormality score than nonexposed infants (7 [interquartile range, 0-41] vs 5 [interquartile range, 0-34]; P≤.001); the findings remained significant (P<.001) after controlling for antenatal confounders. Global efficiency (P<.001), diffuse white matter volume (P=.037), and total brain tissue volume (P=.047) were significantly different between TSE groups in multivariable analyses. On mediation analysis, preterm birth mediated between 0% and 29% of the indirect effect of prenatal tobacco smoke exposure on several measures of brain abnormality outcomes. Thus, prenatal tobacco smoke exposure had a direct adverse effect between 71% and 100% on brain injury or abnormal development. Our study has identified multiple adverse effects of prenatal tobacco smoke exposure on sensitive and objective measures of neonatal brain injury and abnormal development; most cases seemed to be a direct effect of prenatal tobacco smoke exposure on fetal brain development. The results underscored the significant adverse neurostructural effects of prenatal tobacco smoke exposure to tobacco smoke pollutants.

579 ACUTE ISCHEMIC HEART FAILURE: PHARMACOLOGICAL AND INTERVENTIONAL MANAGEMENT OF A FRAIL PATIENT

Abstract An 87-year-old male patient with worsening dyspnea was admitted to our institution. The patient had a history of acute myocardial infarction treated with coronary stenting of the left descending artery (LAD), diagonal (Diag), right coronary artery (RCA), and chronic kidney disease. For acute pulmonary edema, the patient was admitted to our cardiac intensive care unit and rapidly treated with non-invasive positive-pressure ventilation with continuous positive airway pressure (C-PAP), IV high dosage diuretic therapy, inotropes, and vasoactive agents. Chest X-ray revealed cardiomegaly (cardiothoracic ratio, 56%) and pulmonary congestion. Electrocardiogram revealed sinus tachycardia and diffuse ST-segment abnormalities. An echocardiogram demonstrated left ventricular apical akinesia, with a left ventricular ejection fraction (LVEF) of 25% and severe mitral regurgitation. Blood tests revealed very high levels of NT-pro-brain natriuretic peptide (NT-proBNP) (&amp;gt;30000 pg/ml) and myocardial necrosis markers (hs-Trop 5055 ng/l; CK-MB 72 ng/ml). After 24 hours, the patient was placed on intra-aortic balloon pump (IABP) support to further hemodynamic support through the right femoral artery, nonetheless, he showed no improvement in symptoms or urine output. Because of a state of hypoxemic and hypercapnic respiratory failure, non-invasive ventilation (NIV) was given to the patient with a gradual improvement in blood gas analysis. The optimization of diuretic therapy allowed to treat the state of acute oliguric kidney disease, avoiding dialytic treatment. After 48 hours, because of a new worsening in hemodynamic state, we decided for a percutaneous left ventricular assist device (Impella CP, Denver, Massachusetts, USA). After placing the Impella device, coronary angiography was performed, showing critical stenosis of the left main (LM), involving the origin of the left anterior descending artery and a collateralized chronic occlusion of the circumflex artery and the LAD, after the origin of a large first diagonal branch. Because of the high procedural risk, we decided to perform only percutaneous coronary intervention and stent implantation of LM. After 3 days his symptoms improved, the required dose of inotropic agents and furosemide decreased and Impella was removed. After 12 days the patient was admitted to the cardiological ward and discharged after 21 days because of a urinary infection requiring antibiotic therapy. The management of acute heart failure in very old patients is challenging, limiting in many cases the use of invasive procedures such as coronary angiography or left ventricular assist devices. In this case, although the patient presented a very high-risk profile considering age and comorbidities, the use of Impella resulted to be safe and guaranteed hemodynamic support during the procedure of revascularization and in the immediate post-operative phase.

Longitudinal hippocampal diffusion-weighted imaging and T2 relaxometry demonstrate regional abnormalities which are stable and predict subfield pathology intemporallobeepilepsy.

High-resolution (1 mm isotropic) diffusion tensor imaging (DTI) of the hippocampus in temporal lobe epilepsy (TLE) patients has shown patterns of hippocampal subfield diffusion abnormalities, which were consistent with hippocampal sclerosis (HS) subtype on surgical histology. The objectives of this longitudinal imaging study were to determine the stability of focal hippocampus diffusion changes over time in TLE patients, compare diffusion and quantitative T2 abnormalities of the sclerotic hippocampus, and correlate presurgical mean diffusivity (MD) and T2 maps with postsurgical histology. Nineteen TLE patients and 19 controls underwent two high-resolution (1 mm isotropic) DTI and 1.1 × 1.1 × 1 mm3 T2 relaxometry scans (in a subset of 16 TLE patients and 9 controls) of the hippocampus at 3T, with a 2.6 ± 0.8 year inter-scan interval. Within-participant hippocampal volume, MD and T2 were compared between the scans. Contralateral hippocampal changes 2.3 ± 1.0 years after surgery and ipsilateral preoperative MD maps versus postoperative subfield histopathology were evaluated in eight patients who underwent surgical resection of the hippocampus. Reduced volume and elevated MD and T2 of sclerotic hippocampi remained unchanged between longitudinal scans. Focal regions of elevated MD and T2 in bilateral hippocampi of HS TLE were detected consistently at both scans. Regions of high MD and T2 correlated and remained consistent over time. Volume, MD, and T2 remained unchanged in postoperative contralateral hippocampus. Regional elevations of MD identified subfield neuron loss on postsurgical histology with 88% sensitivity and 88% specificity. Focal T2 elevations identified subfield neuron loss with 75% sensitivity and 88% specificity. Diffusion and T2 abnormalities in ipsilateral and contralateral hippocampi remained unchanged between the scans suggesting permanent microstructural alterations. MD and T2 demonstrated good sensitivity and specificity to detect hippocampal subfield neuron loss on postsurgical histology, supporting the potential that high-resolution hippocampal DTI and T2 could be used to diagnose HS subtype before surgery.

Diffusion Tensor and Kurtosis Imaging Findings the First Year following Mild Traumatic Brain Injury.

Despite enormous research interest in diffusion tensor imaging and diffusion kurtosis imaging (DTI; DKI) following mild traumatic brain injury (MTBI), it remains unknown how diffusion in white matter evolves post-injury and relates to acute MTBI characteristics. This prospective cohort study aimed to characterize diffusion changes in white matter the first year after MTBI. Patients with MTBI (n = 193) and matched controls (n = 83) underwent 3T magnetic resonance imaging (MRI) within 72 h and 3- and 12-months post-injury. Diffusion data were analyzed in three steps: 1) voxel-wise comparisons between the MTBI and control group were performed with tract-based spatial statistics at each time-point; 2) clusters of significant voxels identified in step 1 above were evaluated longitudinally with mixed-effect models; 3) the MTBI group was divided into: (A) complicated (with macrostructural findings on MRI) and uncomplicated MTBI; (B) long (1-24 h) and short (< 1 h) post-traumatic amnesia (PTA); and (C) other and no other concurrent injuries to investigate if findings in step 1 were driven mainly by aberrant diffusion in patients with a more severe injury. At 72 h, voxel-wise comparisons revealed significantly lower fractional anisotropy (FA) in one tract and significantly lower mean kurtosis (Kmean) in 11 tracts in the MTBI compared with control group. At 3 months, the MTBI group had significantly higher mean diffusivity in eight tracts compared with controls. At 12 months, FA was significantly lower in four tracts and Kmean in 10 tracts in patients with MTBI compared with controls. There was considerable overlap in affected tracts across time, including the corpus callosum, corona radiata, internal and external capsule, and cerebellar peduncles. Longitudinal analyses revealed that the diffusion metrics remained relatively stable throughout the first year after MTBI. The significant group*time interactions identified were driven by changes in the control rather than the MTBI group. Further, differences identified in step 1 did not result from greater diffusion abnormalities in patients with complicated MTBI, long PTA, or other concurrent injuries, as standardized mean differences in diffusion metrics between the groups were small (0.07 ± 0.11) and non-significant. However, follow-up voxel-wise analyses revealed that other concurrent injuries had effects on diffusion metrics, but predominantly in other metrics and at other time-points than the effects observed in the MTBI versus control group analysis. In conclusion, patients with MTBI differed from controls in white matter integrity already 72 h after injury. Diffusion metrics remained relatively stable throughout the first year after MTBI and were not driven by deviating diffusion in patients with a more severe MTBI.

Pulmonary function test results and radiological findings 90-120 days after COVID-19 pneumonia: a single-center retrospective study

Background: Survivors of Coronavirus Disease 2019 (COVID-19) pneumonia may have permanent loss of lung function and radiological sequelae. There is a need for markers that predict patients for whom follow-up is required. Aim of the study: To identify the risk factors associated with post-COVID-19 radiological and functional findings. Material and Methods: This is a single-center retrospective study performed in a university hospital. We obtained the data from all hospitalized patients with COVID-19 pneumonia. We included those who underwent pulmonary function tests (PFT) and chest computerized tomography (CT) 90-120 days later. We analyzed initial and peak laboratory results (C-reactive protein (CRP), d-dimer, ferritin, and fibrinogen), and the length of hospital and intensive care unit (ICU) stay. We examined the relationship between baseline data and radiological findings and PFT. Results: Fifty-six patients were included in this study. Of these, 31 (55.4%) were women. The mean age of the patients was 55.05 ± 13.29 years. The mean peak ferritin, fibrinogen, d-dimer, and CRP values recorded during hospitalization follow-up were 285.56 ± 339.82, 518.59 ± 186.93, 1.99 ± 5.69, and 98.94 ± 80.77, respectively. The mean length of hospital and ICU stay were 10.21 ± 8.01 and 8.38 ± 8.90 days, respectively. In 18 (32.1%) patients, we observed a restrictive pattern on PFT, and 22 (39.3%) patients had an abnormal diffusion test. In 21 (37.5%) patients we observed ground glass opacities and in 4 (7.1%) patients reticulation was seen on their chest CT. A multivariate logistic regression analysis revealed that the first visit and peak fibrinogen values were significantly associated with abnormal PFT (p = 0.049, R2 = 0.272), while ferritin and CRP levels at the first visit and peak levels were significantly associated with an abnormality on chest CT (p &lt; 0.001, p = 0.05, respectively). Conclusions: High initial and peak ferritin, fibrinogen, and CRP levels were associated with persistent radiological findings on chest CT and abnormal PFT at 90–120 follow-up after COVID-19 pneumonia.

Female Sex Affects Respiratory Function and Exercise Ability in Patients Recovered from COVID-19 Pneumonia.

Background: Coronavirus-19 Disease (COVID-19) may cause persistent symptoms and functional respiratory impairment, known as long COVID. Determinants of long COVID are unclear. Although males experience more severe acute illness, the impact of sex on the occurrence of long-term sequelae is unknown. The aim of this study was to establish whether sex affects pulmonary function, exercise capacity, and clinical outcomes in patients recovered from COVID-19 pneumonia. Materials and Methods: We performed a retrospective analysis on patients evaluated in our "Post-COVID Clinic" after a median follow-up of 128 days from the acute disease. Tests performed included standard spirometry, diffusion capacity of the lung for carbon monoxide (DLCO), and 6-minute walk test (6-MWT). Results: A total of 157 patients (mean age 59.9 ± 12, 91 males) recovered from mild to severe pneumonia, without previous respiratory disease, were included. No differences in demographic data and in the severity of the acute illness were observed between the two study groups, males and females. Abnormal alveolar diffusion was more common and severe among females (DLCO <80% in 31% of males vs. 53% of females, p < 0.01; DLCO <70%, in 20% of males vs. 40% of females, p < 0.01). Severe reduction in 6-MWT was observed in 20% of males versus 46% of females (p < 0.01). Multiple logistic regression showed that female sex was an independent predictor of abnormal DLCO and 6-MWT. The prevalence of symptoms and radiological abnormalities was similar in the two groups. Conclusions: These data show that at 4 months follow-up women recovered from COVID-19 pneumonia are more likely to exhibit a reduced alveolar diffusion capacity and exercise tolerance than men, although a similar severity of the acute disease.

Well-Aerated Lung and Mean Lung Density Quantified by CT at Discharge to Predict Pulmonary Diffusion Function 5 Months after COVID-19.

The aim of this study was to explore the predictive values of quantitative CT indices of the total lung and lung lobe tissue at discharge for the pulmonary diffusion function of coronavirus disease 2019 (COVID-19) patients at 5 months after symptom onset. A total of 90 patients with moderate and severe COVID-19 underwent CT scans at discharge, and pulmonary function tests (PFTs) were performed 5 months after symptom onset. The differences in quantitative CT and PFT results between Group 1 (patients with abnormal diffusion function) and Group 2 (patients with normal diffusion function) were compared by the chi-square test, Fisher's exact test or Mann-Whitney U test. Univariate analysis, stepwise linear regression and logistic regression were used to determine the predictors of diffusion function in convalescent patients. A total of 37.80% (34/90) of patients presented diffusion dysfunction at 5 months after symptom onset. The mean lung density (MLD) of the total lung tissue in Group 1 was higher than that in Group 2, and the percentage of the well-aerated lung (WAL) tissue volume (WAL%) of Group 1 was lower than that of Group 2 (all p &lt; 0.05). Multiple stepwise linear regression identified only WAL and WAL% of the left upper lobe (LUL) as parameters that positively correlated with the percent of the predicted value of diffusion capacity of the lungs for carbon monoxide (WAL: p = 0.002; WAL%: p = 0.004), and multiple stepwise logistic regression identified MLD and MLDLUL as independent predictors of diffusion dysfunction (MLD: OR (95%CI): 1.011 (1.001, 1.02), p = 0.035; MLDLUL: OR (95%CI): 1.016 (1.004, 1.027), p = 0.008). At five months after symptom onset, more than one-third of moderate and severe COVID-19 patients presented with diffusion dysfunction. The well-aerated lung and mean lung density quantified by CT at discharge could be predictors of diffusion function in convalesce.

MRI ischemic and hemorrhagic lesions in arterial and venous territories characterize central nervous system intravascular lymphoma in dogs.

Intravascular lymphoma (IVL) is characterized by the proliferation of large malignant lymphocytes within the lumen of blood vessels. This retrospective, multi-center, case series study aimed to describe the MRI features of confirmed central nervous system IVL in dogs and compare them with histopathological findings. Medical record databases from seven veterinary centers were searched for cases of histologically confirmed IVL. Dogs were included if an MRI was performed. The MRI studies and histopathology samples were reviewed to compare the MRI changes with the histopathological findings. Twelve dogs met the inclusion criteria (12 brains and three spinal cords). Imaging of the brains revealed multifocal T2-weighted/FLAIR hyperintense and T1-weighted iso-hypointense lesions, with variable contrast enhancement; areas of abnormal diffusion both in arterial and venous territories in diffusion-weighted imaging; and meningeal enhancement. On gradient echo images (GRE), the changes comprised tubular susceptibility artifacts, consistent with the "susceptibility vessel sign", and additional variably sized/shaped intraparenchymal susceptibility artifacts. Spinal cord lesions presented as fusiform T2-weighted hyperintensities with scattered susceptibility artifacts on GRE and variable parenchymal and meningeal contrast enhancement. On histopathology, subarachnoid hemorrhages and neuroparenchymal areas of edema and necrosis, with or without hemorrhage, indicating ischemic and hemorrhagic infarctions, were found. These lesions were concurrent with severely dilated meningeal and parenchymal arteries and veins plugged by neoplastic lymphocytes and fibrin. Due to the unique angiocentric distribution of IVL, ischemic and hemorrhagic infarcts of variable chronicity affecting both the arterial and venous territories associated with thrombi formation can be detected on MRI.

Diffuse excessive high signal intensity in the preterm brain on advanced MRI represents widespread neuropathology

Preterm brains commonly exhibit elevated signal intensity in the white matter on T2-weighted MRI at term-equivalent age. This signal, known as diffuse excessive high signal intensity (DEHSI) or diffuse white matter abnormality (DWMA) when quantitatively assessed, is associated with abnormal microstructure on diffusion tensor imaging. However, postmortem data are largely lacking and difficult to obtain, and the pathological significance of DEHSI remains in question. In a cohort of 202 infants born preterm at ≤32 weeks gestational age, we leveraged two newer diffusion MRI models – Constrained Spherical Deconvolution (CSD) and neurite orientation dispersion and density index (NODDI) – to better characterize the macro and microstructural properties of DWMA and inform the ongoing debate around the clinical significance of DWMA. With increasing DWMA volume, fiber density broadly decreased throughout the white matter and fiber cross-section decreased in the major sensorimotor tracts. Neurite orientation dispersion decreased in the centrum semiovale, corona radiata, and temporal lobe. These findings provide insight into DWMA's biological underpinnings and demonstrate that it is a serious pathology.

Diffusion tensor imaging changes in patients with glioma-associated seizures

IntroductionStructural white matter changes associated with certain epilepsy subtypes have been demonstrated using diffusion tensor imaging (DTI). This observational study aims to identify potential water diffusion abnormalities in glioma patients with associated seizures.MethodsTwo cohorts from two centers were analyzed independently: (A) Prospectively recruited patients diagnosed with glioma who received preoperative DTI to measure mean diffusivity (MD) and fractional anisotropy (FA) in regions-of-interest (ROIs) including the marginal tumor zone (TU), adjacent peritumoral white matter as well as distant ipsilateral and contralateral white matter and cortex. Data were compared between patients with and without seizures and tested for statistical significance. (B) A retrospective cohort using an alternative technical approach sampling ROIs in contrast enhancement, necrosis, non-enhancing tumor, marginal non-enhancing tumor zone, peritumoral tissue, edema and non-tumorous tissue.Results(A) The prospective study cohort consisted of 23 patients with 12 (52.2%) presenting with a history of seizures. There were no significant seizure-associated differences in MD or FA for non-tumor white matter or cortical areas. MD-TU was significantly lower in patients with seizures (p = 0.005). (B) In the retrospective cohort consisting of 46 patients with a seizure incidence of 50.0%, significantly decreased normalized values of MD were observed for non-enhancing tumor regions of non-glioblastoma multiforme (GBM) cases in patients with seizures (p = 0.022).ConclusionDTI analyses in glioma patients demonstrated seizure-associated diffusion restrictions in certain tumor-related areas. No other structural abnormalities in adjacent or distant white matter or cortical regions were detected.