Cardiac volume reduction during radiotherapy in patients with esophageal carcinoma

The present study investigated the factors contributing to cardiac volume reduction (CVR) during radiotherapy (RT) in patients with esophageal carcinoma (EC). This retrospective study included patients with EC treated at National Hospital Organization Shikoku Cancer Center (Matsuyama, Japan). Cardiac delineation was based on initial and off-cord boost (spinal cord-sparing approach) planning computed tomography images. The relationship between CVR and other relevant parameters was analyzed. A total of 58 patients with EC were investigated between January 2016 and January 2022. Univariate and multiple regression analyses revealed a statistically significant association between CVR during RT and the change ratio of the inferior vena cava (IVC) volume and body mass index (BMI) loss. In multivariate analysis of CVR of >10%, only the change in IVC volume exhibited a significant association. Conversely, CVR during RT displayed no association with heart dose-volume parameters, laboratory data, or changes in blood pressure and pulse rate. Among the 12 cases with CVR of >10%, the median movement of the left anterior descending coronary artery region (LADR) was 1.35 cm (range, 0.0-2.7 cm). In conclusion, CVR during RT was most strongly associated with changes in IVC volume, suggesting dehydration as the primary cause, rather than radiation-induced heart damage. LADR movement due to a CVR of >10% may lead to LADR radiation overdose.

Novel Clinical Algorithm for Prenatal Monitoring of Congenital Lung Malformations

INTRODUCTION

Congenital lung malformations (CLMs) are readily identified early in pregnancy with a variable natural history. Monitoring for lesion size and mediastinal shift (MS) is recommended following diagnosis. The purpose of this study is to propose a risk-stratified clinical algorithm for prenatal monitoring of CLM.

METHODS

After ethical approval, all fetuses with CLMs evaluated at our fetal center from January 2015 to June 2022 were retrospectively reviewed. Patient demographics, imaging characteristics, and fetal interventions were collected. Lesions were stratified by congenital lung malformation volume ratio (CVR) and the presence of MS. Descriptive statistics and receiver operating characteristic curves were employed in the analysis.

RESULTS

We analyzed 111 patients with a mean of 23.4 wk gestational age, a median CVR of 0.5 (interquartile range, 0.3-1.2), and MS in 76 of 111(68%) patients on initial evaluation. Among low-risk patients (CVR ≤1.1), 96% remained low-risk on final evaluation. No patients transitioned from low to high risk during the growth period. Patients with CVR >1.1 often had persistent MS (P < 0.001). Hydrops (5/111, 5%) and fetal intervention (4/111, 4%) only occurred in patients with CVR >1.1 (P < 0.001, P = 0.002) and MS (P = 0.144, P = 0.214). On receiver operating characteristic curve analysis, initial CVR >1.1 had 100% sensitivity and negative predictive value for hydrops and fetal intervention.

CONCLUSIONS

CLMs with initial CVR ≤1.1 are low risk for hydrops and fetal intervention. We propose a risk-stratified algorithm for the monitoring of CLM during the growth period based on CVR. While our experience suggests that patients with CLM and MS are at higher risk, the current subjective assessment of MS is not adequately predictive. Incorporating an MS grading system may further refine risk stratification in the management of CLM.

Breath-hold BOLD fMRI without CO2 sampling enables estimation of venous cerebral blood volume: potential use in normalization of stimulus-evoked BOLD fMRI data

BOLD fMRI signal has been used in conjunction with vasodilatory stimulation as a marker of cerebrovascular reactivity (CVR): the relative change in cerebral blood flow (CBF) arising from a unit change in the vasodilatory stimulus. Using numerical simulations, we demonstrate that the variability in the relative BOLD signal change induced by vasodilation is strongly influenced by the variability in deoxyhemoglobin-containing cerebral blood volume (CBV), as this source of variability is likely to be more prominent than that of CVR. It may, therefore, be more appropriate to describe the relative BOLD signal change induced by an isometabolic vasodilation as a proxy of deoxygenated CBV (CBVdHb) rather than CVR. With this in mind, a new method was implemented to map a marker of CBVdHb, termed BOLD-CBV, based on the normalization of voxel-wise BOLD signal variation by an estimate of the intravascular venous BOLD signal from voxels filled with venous blood. The intravascular venous BOLD signal variation, recorded during repeated breath-holding, was extracted from the superior sagittal sinus in a cohort of 27 healthy volunteers and used as a regressor across the whole brain, yielding maps of BOLD-CBV. In the same cohort, we demonstrated the potential use of BOLD-CBV for the normalization of stimulus-evoked BOLD fMRI by comparing group-level BOLD fMRI responses to a visuomotor learning task with and without the inclusion of voxel-wise vascular covariates of BOLD-CBV and the BOLD signal change per mmHg variation in end-tidal carbon dioxide (BOLD-CVR). The empirical measure of BOLD-CBV accounted for more between-subject variability in the motor task-induced BOLD responses than BOLD-CVR estimated from end-tidal carbon dioxide recordings. The new method can potentially increase the power of group fMRI studies by including a measure of vascular characteristics and has the strong practical advantage of not requiring experimental measurement of end-tidal carbon dioxide, unlike traditional methods to estimate BOLD-CVR. It also more closely represents a specific physiological characteristic of brain vasculature than BOLD-CVR, namely blood volume.

Multidisciplinary management of a large microcystic congenital pulmonary airway malformation: case report and literature review

INTRODUCTION

Congenital pulmonary airway malformations (CPAMs) are rare sporadic lesions frequently associated with poor fetal prognosis. Type 3 CPAMs are characterized by small hyperechogenic cysts (<5 mm). Hydrops often develops secondarily, and the fetal survival rate is approximately 5% in this setting.

CASE PRESENTATION

We present a case of a large type 3 CPAM complicated by fetal hydrops. The lesion was detected at 19 gestational weeks (GW) and confirmed by fetal MRI at 29 GW. At 22 GW, a course of maternal steroids was given as a possible treatment of type 3 CPAM. Peritoneal-amniotic shunt was placed twice to reduce fetal ascites, with unsatisfactory results. Similarly, polyhydramnios was relieved by two amnioreductions, but redeveloped soon after. A baby girl was delivered spontaneously at 33 GW and received a two-stage partial lobectomy in the first three months of life. Desaturations necessitated challenging invasive oscillatory ventilation between stages. Her outcome is unexpectedly positive and she may expect a good quality of life. She now approaches one year of age, with near-to-normal growth and developmental milestones.

DISCUSSION

Type 3 CPAMs complicated by fetal hydrops are associated with high perinatal mortality. While open fetal surgery remains a viable option in select specialist centers, antenatal interventions are typically ineffective. The survival of this infant can be attributed to prenatal management and early postnatal surgical intervention. The lack of guidelines for ventilation in this setting was a significant challenge for neonatal intensivists. Multidisciplinary vigilance and collaboration with frequent specialist follow ups were the key to success for both mother and child.

Diaschisis Profiles in the Cerebellar Response to Hemodynamic Stimuli: Insights From Dynamic Measurement of Cerebrovascular Reactivity to Identify Occult and Transient Maxima

BACKGROUND

Crossed cerebellar diaschisis (CCD) refers to depressions in perfusion and metabolism within the cerebellar hemisphere contralateral to supratentorial disease. Prior investigation into CCD in cerebrovascular reactivity (CVR) has been limited to terminal CVR estimations (CVRend ). We recently have demonstrated the presence of unsustained CVR maxima (CVRmax ) using dynamic CVR analysis, offering a fully dynamic characterization of CVR to hemodynamic stimuli.

PURPOSE

To investigate CCD in CVRmax from dynamic blood oxygen level-dependent (BOLD) MRI, by comparison with conventional CVRend estimation.

STUDY TYPE

Retrospective.

POPULATION

A total of 23 patients (median age: 51 years, 10 females) with unilateral chronic steno-occlusive cerebrovascular disease, without prior knowledge of CCD status.

FIELD STRENGTH/SEQUENCE

A 3-T, T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and acetazolamide-augmented BOLD imaging performed with a gradient-echo echo-planar imaging (EPI) sequence.

ASSESSMENT

A custom denoising pipeline was used to generate BOLD-CVR time signals. CVRend was established using the last minute of the BOLD response relative to the first-minute baseline. Following classification of healthy versus diseased cerebral hemispheres, CVRmax and CVRend were calculated for bilateral cerebral and cerebellar hemispheres. Three independent observers evaluated all data for the presence of CCD.

STATISTICAL TESTS

Pearson correlations for comparing CVR across hemispheres, two-proportion Z-tests for comparing CCD prevalence, and Wilcoxon signed-rank tests for comparing median CVR. The level of statistical significance was set at P ≤ 0.05.

RESULTS

CCD-related changes were observed on both CVRend and CVRmax maps, with all CCD+ cases identifiable by inspection of either map. Diseased cerebral and contralateral cerebellar hemispheric CVR correlations in CCD+ patients were stronger when using CVRend (r = 0.728) as compared to CVRmax (r = 0.676). CVR correlations between healthy cerebral hemispheres and contralateral cerebellar hemispheres were stronger for CVRmax (r = 0.739) than for CVRend (r = 0.705).

DATA CONCLUSION

CCD-related alterations could be observed in CVR examinations. Conventional CVRend may underestimate CVR and could exaggerate CCD.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 3.

Serial lung mass volume ratios as prognostic indicators of neonatal respiratory morbidity in fetal pulmonary malformations

BACKGROUND

Several studies have shown that the congenital pulmonary airway malformation volume ratio is a useful prognosticator of neonatal outcome in prenatally diagnosed lung lesions. However, there remains a lack of consensus on which congenital pulmonary airway malformation volume ratio values have the best predictive value because of operator dependence, inherent changes in lung lesion size throughout gestation, and the widespread use of maternal steroids.

OBJECTIVE

This study sought to determine the association between serial congenital pulmonary airway malformation volume ratio measurements and neonatal outcomes among fetuses with lung malformations.

STUDY DESIGN

This was a retrospective cohort study of fetuses with a prenatally diagnosed lung malformation managed at 2 major fetal centers from January 2010 to December 2021. Prenatal variables, including prospectively measured congenital pulmonary airway malformation volume ratio measurements (initial, maximum, and final), were analyzed. The results were correlated with 3 outcome measures, namely surgical resection before 30 days of life, a need for supplemental O2 at birth, and endotracheal intubation at birth. Statistical analyses were performed using receiver operating characteristic curve analyses, Welch 2 sample t tests, and multivariable logistic regressions (P<.05).

RESULTS

There were 123 fetuses with isolated lung lesions identified. Eight (6.5%) had hydrops. The mean initial congenital pulmonary airway malformation volume ratio was 0.67±0.61 cm2 at 22.9±3.9 weeks' gestation. The mean maximum congenital pulmonary airway malformation volume ratio was 1.08 ± 0.94 cm2 at 27.0 ± 4.0 weeks' gestation. The mean final congenital pulmonary airway malformation volume ratio was 0.58±0.60 cm2 at 33.2±4.1 weeks' gestation. At a mean gestational age at delivery of 38.3±2.6 weeks, 15 (12.2%) underwent neonatal lung resection for symptomatic disease. In a multivariable regression, all 3 congenital pulmonary airway malformation volume ratio measurements showed a significant correlation with neonatal lung resection (P<.001). Optimal congenital pulmonary airway malformation volume ratio cutoffs were established based on an initial congenital pulmonary airway malformation volume ratio of ≥0.8 cm2, maximum congenital pulmonary airway malformation volume ratio of ≥1.5 cm2, and a final congenital pulmonary airway malformation volume ratio of ≥1.3 cm2 with associated areas under the curve of 0.89, 0.97, and 0.93, respectively. The final congenital pulmonary airway malformation volume ratio had the highest specificity for predicting surgical lung resection in the early postnatal period.

CONCLUSION

Measuring congenital pulmonary airway malformation volume ratios throughout pregnancy in fetuses with pulmonary malformations has clinical value for prenatal counseling and planning care transition after delivery. Fetuses with a final congenital pulmonary airway malformation volume ratio of more than 1.3 cm2 are likely to require neonatal surgery and therefore should be delivered at tertiary care centers with a neonatal intensive care unit and pediatric surgical expertise.

Can we predict the need for postnatal surgery in patients with prenatal fetal lung masses detected by CVR value?

AIM

The purpose of this study is to evaluate whether CPAM-volume ratio (CVR) can predict postnatal management (follow up for resolution and surgical treatment) in fetuses with fetal lung masses in the prenatal period.

MATERIALS AND METHODS

44 patients who presented at our center with prenatally diagnosed CPAM (Congenital Pulmonary Airway Malformation) and BPS (Bronchopulmonary Sequestration) were analyzed. Obstetric history and outcomes, karyotype results, CVR, additional sonographic findings, characteristics of masses were recorded. CVR was calculated for all cases. İn the study we sought to identify a CVR threshold and did not use the thresholds classically used in the literature.

RESULTS

20 fetal BPS and 24 CPAM cases were analyzed. After excluding 5 patients, 46% of the patients were diagnosed with BPS and 54% with CPAM. İn this study the cut off < 0,53 for CVR is taken, it predicts the no need for postnatal surgery with a sensitivity of 85% and a specificity of 88%. When we take the > 0,76 cut-off value for patients who will require emergency surgery within the first 10 days, it predicts the need for surgery with 90% sensitivity and 89% specificity. In addition, it was determined that all patients with mediastinal shift were operated.

CONCLUSION

We believe that the CVR value and the presence of mediastinal shift should be evaluated in all cases of CPAM and BPS for prediction of the surgery. Proper counseling about the prognosis could be given to the family in cases with mediastinal shift and CVR value above 0,76.

Diagnostic value of congenital pulmonary airway malformation volume ratio for fetal hydrops due to congenital lung malformations: a systematic review and meta-analysis

Objective

Meta-analysis was used to evaluate the diagnostic value of a CVR cut-off value of 1.6 for fetal hydrops due to congenital lung malformation (CLM).

Methods

A systematic search of PubMed, Embase, Web of Science, CNKI, VIP, and Wanfang published before 7/30/2021 for the value of a congenital pulmonary airway malformation volume ratio (CVR) cut-off value of 1.6 for the diagnosis of fetal hydrops. According to the inclusion and exclusion criteria, the literature that met the requirements were obtained. A total of 75 articles were retrieved, and 12 articles were included for further analysis. The quality of these studies was evaluated according to the Quality Assessment for Studies of Diagnostic Accuracy tool (QUADAS-2) criteria. The Q test and heterogeneity I² were used to evaluate the heterogeneity due to non-threshold effects, and Stata 15.0 was used for statistical analysis to evaluate the diagnostic value of the CVR cutoff value of 1.6 for fetal hydrops due to CLM.

Results

A total of 12 studies were included. The QUADAS-2 indicated that the risk of bias was relatively low, and the clinical applicability was relatively high. Statistical analysis was performed on included studies using a random effect model. Meta-analysis showed that the pooled sensitivity, specificity, diagnostic ratio and summary receiver operating characteristic (SROC) for the diagnosis of fetal hydrops by CVR were 0.86 (95% CI, 0.72–0.93; I² = 59.84), 0.90 (95% CI, 0.88–0.93; I² = 31.94), 58 (95% CI, 22–149; I² = 100%), 0.93 (95% CI, 0.91–0.95).

Conclusions

The sensitivity and specificity of CVR cut-off value 1.6 for the diagnosis of CLM-induced fetal hydrops were high, no publication bias was observed, and the CVR cut-off value 1.6 is meaningful for the early diagnosis prediction of CLM-induced fetal hydrops.

Severity Evaluation of Regional Cerebrovascular Reactivity in Acute Stroke Patients using SPECT

BACKGROUND

Cerebrovascular reactivity (CVR), as measured using perfusion single photon emission computed tomography (SPECT), is an important indicator for the treatment and prognosis of cerebrovascular disease, but there are few studies of acute stroke or small vascular disease using SPECT.

OBJECTIVE

This study was to evaluate the regional severity with quantitatively determined CVR in patients with acute stroke.

METHODS

Fifty-eight patients who took brain SPECT images were selected to localize quantitative CVR values. The severity of the disease (Grade 1 to 4) was determined through image-based clinical assessment in the absence and presence of a CVR map and their results were compared.

RESULTS

In 1st diagnosis without the map, the mean CVR values of Grades 2 and 3 were -6.07% and -9.12%, respectively (P=0.034), while they were -4.78% and -12.34% in 2nd diagnosis with the map, respectively (P<0.001), suggesting that the CVR difference with the map was much more pronounced than without the map. Furthermore, in the ROC analysis, the diagnostic sensitivity between Grades 2 and 3 in 2nd diagnosis (AUC=0.899, P<0.001) was substantially greater than 1st diagnosis (AUC=0.646, P=0.048).

CONCLUSION

This study demonstrated the quantitative CVR maps could reinforce the clinical evaluation of cerebral severity by showing that they can provide statistically significant results between severity and CVR. Furthermore, this study was the first to evaluate the effectiveness of quantitative CVR by examining the difference in the presence or absence of CVR in patients with acute stroke.

Medullary vein architecture modulates the white matter BOLD cerebrovascular reactivity signal response to CO2: Observations from high-resolution T2* weighted imaging at 7T

Brain stress testing using blood oxygenation level-dependent (BOLD) MRI to evaluate changes in cerebrovascular reactivity (CVR) is of growing interest for evaluating white matter integrity. However, even under healthy conditions, the white matter BOLD-CVR response differs notably from that observed in the gray matter. In addition to actual arterial vascular control, the venous draining topology may influence the WM-CVR response leading to signal delays and dispersions. These types of alterations in hemodynamic parameters are sometimes linked with pathology, but may also arise from differences in normal venous architecture. In this work, high-resolution T2*weighted anatomical images combined with BOLD imaging during a hypercapnic breathing protocol were acquired using a 7 tesla MRI system. Hemodynamic parameters including base CVR, hemodynamic lag, lag-corrected CVR, response onset and signal dispersion, and finally ΔCVR (corrected CVR minus base CVR) were calculated in 8 subjects. Parameter maps were spatially normalized and correlated against an MNI-registered white matter medullary vein atlas. Moderate correlations (Pearson's rho) were observed between medullary vessel frequency (MVF) and ΔCVR (0.52; 0.58 for total WM), MVF and hemodynamic lag (0.42; 0.54 for total WM), MVF and signal dispersion (0.44; 0.53 for total WM), and finally MVF and signal onset (0.43; 0.52 for total WM). Results indicate that, when assessed in the context of the WM venous architecture, changes in the response shape may only be partially reflective of the actual vascular reactivity response occurring further upstream by control vessels. This finding may have implications when attributing diseases mechanisms and/or progression to presumed impaired WM BOLD-CVR.

Molecular detection and characterization of African swine fever virus from field outbreaks in domestic pigs, Mizoram, India

African swine fever (ASF) is a devastating haemorrhagic disease of domestic pigs, which can cause mortality up to 100%. Sudden mortality in pigs following an acute course of systemic disease was investigated in Mizoram state of India and confirmed the outbreak as ASF. Affected pigs suffered from severe depression, high fever, bloody diarrhoea, cutaneous haemorrhages and showed haemorrhagic lesions in visceral organs. The outbreak was confirmed by detection of p72, p54 and the central variable region of B602L genes by PCR in representative tissue samples collected from dead pigs. The nucleotide and phylogenetic analyses of p72, p54 and B602L characterized the ASFV as genotype II. Interestingly, the analysis of B602L gene has revealed that the ASFV from Mizoram state of India is more closely linked to the Eurasian ASFV strains isolated prior to 2014 and discriminated the Indian strains in two separate groups indicating that the source of origin for the Mizoram outbreak could be different from that of the other states of India.

Prediction of postnatal outcome in fetuses with congenital lung malformation: 2-year follow-up study

OBJECTIVES

To identify, in fetuses with a congenital lung malformation (CLM), prenatal predictors of the need for postnatal respiratory support and the need for surgery by calculating the CLM volume ratio (CVR), and to evaluate the concordance between the prenatal appearance and the postnatal type of CLM.

METHODS

This was an analysis of prenatal, perinatal and postnatal data from fetuses diagnosed with a CLM at the Erasmus University Medical Center - Sophia Children's Hospital in Rotterdam, The Netherlands, between January 2007 and December 2016. For all included fetuses, CVR was measured retrospectively on stored ultrasound images obtained at 18 + 1 to 24 + 6 weeks (US1), 25 + 0 to 29 + 6 weeks (US2) and/or 30 + 0 to 35 + 6 weeks' gestation (US3). Postnatal diagnosis of CLM was based on computed tomography or histology. Primary outcomes were the need for respiratory support within 24 h and surgery within 2 years after birth.

RESULTS

Of the 80 fetuses with a CLM included in this study, 14 (18%) required respiratory support on the first postnatal day, and 17 (21%) required surgery within 2 years. Only the CVR at US2 was predictive of the need for respiratory support, with a cut-off value of 0.39. Four of 16 (25%) fetuses which showed full regression of the CLM prenatally required respiratory support within 24 h after birth. The CVR at US1, US2 and US3 was predictive of surgery within 2 years. Overall, the prenatal appearance of the CLM showed low concordance with the postnatal type. Prenatally suspected microcystic congenital pulmonary airway malformation (CPAM) was shown on computed tomography after birth to be congenital lobar overinflation in 15/35 (43%) cases. Respiratory support within 24 h after birth and surgical resection within 28 days after birth were needed in all cases of macrocystic CPAM.

CONCLUSIONS

CVR can predict the need for respiratory support within 24 h after birth and for surgery within 2 years. Regression of a CLM prenatally does not rule out respiratory problems after birth. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. - Legal Statement: This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Obstetrician patterns of steroid administration for the prenatal management of congenital pulmonary airway malformations

BACKGROUND

Congenital pulmonary airway malformation (CPAM) is the most common prenatally-diagnosed lung malformation. This lesion, classified as macrocystic or microcystic, can lead to significant fetal compromise. Management options include observation, maternal antenatal steroid administration, and fetal surgical intervention. Current evidence suggests that microcystic (but not macrocystic) lesions and those with a cyst volume ratio (CVR) >1.6 are responsive to steroid therapy. The objective of this study was to identify patterns of prenatal steroid administration for the management of CPAMs and to identify characteristics of CPAMs prompting steroid administration.

METHODS

An 18-question survey was distributed to obstetricians from the Pregnancy-Related Care Research Network (PRCRN) and the North American Fetal Therapy Network (NAFTNet), from January to April 2019, to capture antenatal steroid prescribing patterns.

RESULTS

Response rates were 28.3% (138/487) for PRCRN and 63.3% (19/30) for NAFTNet. Among PRCRN members, 16.8% administered prenatal steroids, with most (77.2%) doing so for both microcystic and macrocystic CPAMs; corresponding percentages for NAFTNet members were 90.9% and 52.6%. Two thirds (65.6%) of obstetricians who administer steroids do so for a CVR > 1.6, without evidence of mediastinal shift or hydrops fetalis.

CONCLUSIONS

There is a lack of consensus among obstetricians as to the CPAM characteristics that should prompt administration of prenatal steroids. Many surveyed obstetricians do not use cyst type or CVR to guide decision-making regarding steroid therapy.

Altered cerebrovascular reactivity due to respiratory rate and breath holding: a BOLD-fMRI study on healthy adults

Cerebrovascular reactivity (CVR) is of great significance for the treatment and prevention of cerebrovascular diseases. CVR can be mapped using the blood oxygenation level-dependent (BOLD) signal of fMRI. Breath holding (BH) is a reliable method to produce the desired increase in arterial CO₂, while its application in clinical research is limited due to subject's compliance and variability. BH task with variable respiratory rates could allow more flexibility in clinical populations. In this study, 50 healthy volunteers were scanned for end-inspiration BH tasks with three different respiration rates. For the three respiratory rates BH tasks, the CVR was estimated based on the BOLD signal and general linear model (GLM) separately. Specifically, the extra time delay was considered for the hemodynamic response function, and the optimal delay was estimated for each voxel. To measure CVR in grey matter, BOLD signals of end-inspiration BH were used as regressors in general linear models to quantify their impact on CVR. This was performed for regions and voxels. Systematic differences were observed between the three end-inspiratory breathing rates. The greatest increase in activation intensity was found in fast breathing followed by self-paced and slow breathing. We conclude that the BH task of variable respiratory rates allows for CVR measurement, making breath-holding challenges more flexible and appropriate for routine practice.

Genetic characterization of African swine fever virus from domestic pigs in India

African swine fever (ASF) is the most dreaded disease of pigs, which can cause mortality of up to 100%. Following disease outbreaks with high mortality in pigs in two states of north-east India, namely Arunachal Pradesh and Assam in early 2020, we confirmed the first occurrence of African swine fever (ASF) in domestic pigs in India by real-time PCR, virus isolation and nucleotide sequencing. Genetic analyses in three independent genomic regions (B646L gene encoding the p72 protein, E183L gene encoding the p54 protein and the central variable region (CVR) of B602L gene) showed that the Indian ASF viruses are similar to the post-2007-p72-genotype II viruses reported from Asia and Europe, suggesting the transboundary expansion of ongoing ASF outbreaks in the region.

Molecular Characterization of African Swine Fever Virus Isolates in Estonia in 2014-2019

After the extensive spread of the African swine fever virus (ASFV) genotype II in Eastern Europe, the first case of African swine fever (ASF) in Estonia was diagnosed in September 2014. By the end of 2019, 3971 ASFV-positive wild boars were found, and 27 domestic pig outbreaks were reported. A selection of ASFV isolates from wild boar and domestic pigs (during the period of September 2014–2019) was molecularly characterized using standardized genotyping procedures. One of the proven markers to characterize this virus is the central variable region (CVR) within the B602L gene. In summer 2015, a new ASFV genotype II CVR variant 2 (GII-CVR2) was confirmed in Estonia. The results suggest that the GII-CVR2 variant was only confirmed in wild boar from a limited area in southern Estonia in 2015 and 2016. In addition to GII-CVR2, a single nucleotide polymorphism (SNP) that resulted in amino acid change was identified within the genotype II CVR variant 1 (GII-CVR1). The GII-CVR1/SNP1 strain was isolated in Estonia in November 2016. Additional GII-CVR1/SNP1 cases were confirmed in two neighbouring counties, as well as in one outbreak farm in June 2017. Based on the available data, no GII-CVR2 and GII-CVR1/SNP1 have been reported by other affected European countries. The spread of variant strains in Estonia has been limited over time, and restricted to a relatively small area.

Prenatal Imaging to Predict Need for Urgent Perinatal Surgery in Congenital Lung Lesions

BACKGROUND

Congenital lung malformations (CLMs) have a variable natural history: some patients require urgent perinatal surgical intervention (UPSI) and others remain asymptomatic. These lesions have potential growth until 26-28 wk gestation. CLM volume ratio (CVR) has been shown to predict the risk of hydrops in CLMs. However, no criteria exist to delineate lesions requiring urgent surgical intervention in the perinatal period. Our goal was to determine prenatal diagnostic features that predict the need for UPSI in patients diagnosed with CLM.

METHODS

Records and imaging features of all fetuses evaluated by our fetal center between May 2015 and December 2018 were retrospectively reviewed. Data included demographics, fetal ultrasound and magnetic resonance imaging, CVR, surgical treatment, and outcome. Features were analyzed for their ability to predict the need for UPSI.

RESULTS

Sixty-four patients were referred for CLM, with 48 patients serially followed. Nine (18.8%) patients were followed nonoperatively, 35 (72.9%) underwent resection, and four (8.3%) were lost to follow-up. Of the patients who underwent resection, 24 (68.5%) were electively resected and 11 were urgently resected. Five (14.3%) patients underwent ex utero intrapartum treatment resection, and six (17.1%) were urgently resected for symptomatic CLM. There were no cases of UPSI with final CVR <1.1. Of the patients with final CVR 1.1-1.7, 43% required urgent resection. CVR ≥1.1 has 100% sensitivity and 87.8% specificity to predict patients requiring UPSI (area under the curve of 0.98).

CONCLUSIONS

A final CVR ≥1.1 is highly predictive for UPSI. Patients with a final CVR ≥1.1 should be referred for delivery at centers with pediatric surgeons equipped for potential UPSI for CLM.

Reproducibility of a ramping protocol to measure cerebral vascular reactivity using functional magnetic resonance imaging

Though individual differences in arterial carbon dioxide and oxygen levels inherently exist, the degree of their influence on cerebral vascular reactivity (CVR) is less clear. We examined the reproducibility of BOLD signal changes to an iso-oxic ramping P_et CO₂ protocol. CVR changes were induced by altering P_et CO₂ while holding P_et O₂ constant using a computer-controlled sequential gas delivery (SGD) device. Two MRI scans, each including a linear change in P_et CO₂ , were performed using a 3-Tesla (3T) scanner. This ramp sequence consisted of 1 min at 30 mmHg followed by 4 min period during where P_et CO₂ was linearly increased from 30 to 50 mmHg, 1 min at 51 mmHg, and concluded with 4 min at baseline. The protocol was repeated at a separate visit with 3 days between visits (minimum). Intraclass correlation coefficients (ICC) and coefficients of variation (CV) were used to verify reproducibility. Eleven subjects (6 females; mean age 26.5 ± 5.7 years) completed the full testing protocol. Good reproducibility was observed for the within-visit ramp sequence (Visit 1: ICC = 0.82, CV = 6.5%; Visit 2: ICC = 0.74, CV = 6.4%). Similarly, ramp sequence were reproducible between visits (Scan 1: ICC = 0.74, CV = 6.5%; Scan 2: ICC = 0.66, CV = 6.1%). Establishing reproducible methodologies for measuring BOLD signal changes in response to P_et CO₂ alterations using a ramp protocol will allow researchers to study CVR functionality. Finally, adding a ramping protocol to CVR studies could provide information about changes in CVR over a broad range of P_et CO₂ .

Comparative Analysis of Classification Methods with PCA and LDA for Diabetes

BACKGROUND

The modern society is extremely prone to many life-threatening diseases, which can be easily controlled as well as cured if diagnosed at an early stage. The development and implementation of a disease diagnostic system have gained huge popularity over the years. In the current scenario, there are certain factors such as environment, sedentary lifestyle, genetic (hereditary) are the major factors behind the life threatening diseases such as 'diabetes.' Moreover, diabetes has achieved the status of the modern man's leading chronic disease. So one of the prime needs of this generation is to develop a state-of-the-art expert system which can predict diabetes at a very early stage with a minimum of complexity and in an expedited manner. The primary objective of this work is to develop an indigenous and efficient diagnostic technique for detection of diabetes. Method & Discussion: The proposed methodology comprises of two phases: In the first phase The Pima Indian Diabetes Dataset (PIDD) has been collected from the UCI machine learning repository databases and Localized Diabetes Dataset (LDD) has been gathered from Bombay Medical Hall, Upper Bazar Ranchi, Jharkhand, India. In the second phase, the dataset has been processed through two different approaches. The first approach entails classification through Adaboost, Classification via Regression (CVR), Radial Basis Function Network (RBFN), K-Nearest Neighbor (KNN) on Pima Indian Diabetes Dataset and Localized Diabetes Dataset. In the second approach, Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) have been applied as a feature reduction method followed by using the same set of classification methods used in the first approach. Among all of the implemented classification methods, PCA_CVR achieves the maximum performance for both the above mentioned datasets.

CONCLUSION

In this article, comparative analysis of outcomes obtained by with and without the use of PCA and LDA for the same set of classification method has been done w.r.t performance assessment. Finally, it has been concluded that PCA & LDA both are useful to remove the insignificant features, decreasing the expense and computation time while improving the ROC and accuracy. The used methodology may similarly be applied to other medical diseases.

Prenatal natural history of congenital pulmonary malformations: MALFPULM population-based cohort study

OBJECTIVES

To assess prenatal changes in the volume of congenital pulmonary malformations (CPM) and examine whether these changes differ in lesions that appear cystic on ultrasound compared with hyperechoic lesions, and to study the relationship between CPM volume and risk of fetal compression.

METHODS

We conducted a nationally representative, multicenter, prospective cohort study, which included 579 ultrasound examinations in 176 pregnant women with a diagnosis of fetal CPM, between March 2015 and November 2016. Several ultrasound examinations were performed between diagnosis and delivery, including measurement of CPM volume. We modeled changes in CPM volume ratio (CVR) as a function of gestational age, overall and for cystic/mixed vs hyperechoic malformations, and examined the association between CVR and signs of compression during pregnancy.

RESULTS

When modeling CVR changes over time, there was a statistically significant decrease in CVR with increasing gestational age (P < 0.001), but the pattern of change differed according to CPM phenotype at first ultrasound examination: cystic/mixed CPM were characterized by a monotonic decrease in CVR with increasing gestational age (P = 0.002), whereas hyperechoic CPM showed an initial increase in CVR up to 27 weeks of gestation, followed by a decrease thereafter (P < 0.001). Peak CVR values were predicted as early as 21-22 weeks for cystic/mixed CPMs compared with 25-26 weeks for hyperechoic malformations. Regardless of CPM phenotype, fetuses that showed no sign of compression at any point had substantially lower CVR at first CVR measurement, and the CVR remained relatively constant thereafter. Among the subpopulation of fetuses with no sign of compression at first CVR measurement, the odds of a subsequent compression was 7-fold higher (adjusted odds ratio, 7.0; 95% CI, 1.6-29.9) if initial CVR was > 0.4 vs CVR ≤ 0.4 cm² .

CONCLUSIONS

Predicted changes in CVR during pregnancy differ between cystic and hyperechoic malformations. This may be the result of different pathophysiological mechanisms or differences in the timing of occurrence of these different types of CPM. CVR measured at the initial diagnostic ultrasound examination was strongly associated with the odds of subsequent compression. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Congenital Cystic Adenomatoid Malformation Volume Ratio in Prenatal Assessment of Prognosis of Fetal Pulmonary Sequestrations

This study aimed to evaluate the prognosis of pulmonary sequestration (PS) by measuring congenital cystic adenomatoid malformation volume ratio (CVR) value in fetal congenital PS. The fetal CVR in 49 cases of fetal PS diagnosed by prenatal ultrasound in Xiangyang No. 1 People's Hospital from March 2010 to June 2017 were measured, and the clinical outcomes were observed. According to the prenatal ultrasound CVR value, 49 fetuses diagnosed with PS were divided into 2 groups: group 1 with CVR≥1.26, and group 2 with CVR<1.26. The incidence rate of fetal edema, respiratory distress symptoms and survival rate were compared between the two groups. The risk factors of the fetal PS were evaluated by single and multiple Logistic regression analysis. The correlation between CVR and fetal prognosis was analyzed. Of the 49 fetuses, there were 34 cases of PS (ILS) type (69.39%, 34/49), 10 cases of PS (ELS) type I (20.41%, 10/49) and 5 cases of PS (ELS) type II (10.20%, 5/49). Forty-six cases (93.88%, 46/49) were born alive, there was 1 case (CVR ≥1.26) (2.04%, 1/49) of induced abortion, and 2 cases (CVR ≥1.26) (4.08%, 2/49) of stillbirths. In group 1 (n=24), 21 cases were born alive, and the incidence rate of newborn respiratory distress and fetal edema was 100% (21/21) and 79.17% (19/24) respectively. In group 2 (n=25), there were 3 cases (12%,3/25) of newborn respiratory distress, 3 cases (12%, 3/25) of fetal edema, and the rate of live birth was 100%. There were statistically significant differences between the two groups in the incidence of fetal edema, postpartum respiratory symptoms and survival rate. CVR was a risk factor for PS and was associated with fetal prognosis. CVR in the midtrimester of pregnancy is an effective index to evaluate the prognosis of fetal PS. CVR ≥1.26 is associated with an increased risk of fetal edema, infant respiratory distress and intrauterine or postnatal death.

Genetic characterization of African swine fever virus in Cameroon, 2010-2018

African swine fever (ASF) is a highly lethal haemorrhagic disease in domestic and wild swine that has acquired great importance in sub-Saharan Africa since 1997. ASF was first reported in Cameroon in 1982 and was detected only in Southern Cameroon (South, West, East, Northwest, Southwest, Littoral, and Centre regions) until February 2010 when suspected ASF outbreaks were reported in the North and Far North regions. We investigated those outbreaks by analysing samples that were collected from sick pigs between 2010 and 2018. We confirmed 428 positive samples by ELISA and real-time PCR and molecularly characterized 48 representative isolates. All the identified virus isolates were classified as ASFV genotype I based on the partial B646L gene (C-terminal end of VP72 gene) and the full E183L gene encoding p54 protein analysis. Furthermore, analysis of the central variable region (CVR) within the B602L gene demonstrated that there were 3 different variants of ASFV genotype I, with 19, 20, and 21 tetrameric tandem repeat sequences (TRSs), that were involved in the 2010-2018 outbreaks in Cameroon. Among them, only variant A (19 TRSs) was identical to the Cam/82 isolate found in the country during the first outbreaks in 1981-1982. This study demonstrated that the three variants of ASFV isolates involved in these outbreaks were similar to those of neighbouring countries, suggesting a movement of ASFV strains across borders. Designing common control measures in affected regions and providing a compensation programme for farmers will help reduce the incidence and spread of this disease.

Predictors of early lobectomy after birth in prenatally diagnosed congenital pulmonary airway malformation

PURPOSE

The purpose of this study was to clarify the relationship between congenital pulmonary airway malformation volume ratio (CVR) of bronchial atresia (BA), CVR of congenital cystic adenomatoid malformations (CCAM), and time of surgery after birth.

METHOD

We retrospectively analyzed data of 36 BA and CCAM cases, prenatally diagnosed as CPAM from 2009 through 2014.

RESULTS

Within 2 h after birth, 12 neonatal patients underwent emergent (EMG) lobectomy. Five cases of lobectomy were performed urgently (UG) from 12 to 48 h after birth. Four cases of lobectomy were required within 30 days after birth (early = EAG). We performed lobectomy in 15 other patients at 11 months after birth (late = LG). Of the EMG cases, 11 were macrotype CCAM (maximal CVR >2.0), and 4 of 5 UG cases were microtype CCAM (CVR >2.0). Of the EAG cases, 3 of 4 were macrotype CCAM with CVR of <1.5. Of 15 LG, 13 were BA and showed a CVR of 0.13-3.0 (median, 0.78). The CVR of the cases operated on within 48 h after birth was significantly larger than that of the cases operated on after 2 weeks (p = 0.001).

CONCLUSION

EMG or UG lobectomy was usually required after birth in CCAM, indicating maximal CVR >2.0. By contrast, elective surgery was performed in most BA cases.

LEVEL OF EVIDENCE

IV.

Early endothelial progenitor cells and vascular stiffness in psoriasis and psoriatic arthritis

BACKGROUND

Both psoriasis (Ps) and psoriasis arthritis (PsA) have been associated with increased cardiovascular risk. Also, both are characterized by increased neovascularization. Endothelial progenitor cells (EPCs) have been implicated in promoting vascular repair in ischemic diseases. The aim of the study was to correlate the EPC system with CV risk factors and with parameters of vascular stiffness in Ps and PsA.

METHODS

Twenty-six healthy subjects, 30 patients with Ps, and 31 patients PsA were included in the study. eEPC regeneration was evaluated by a colony-forming assay, circulating eEPCs were measured by cytometric analysis. For vascular analysis, all subjects underwent quantification of pulse wave velocity (PWV) and augmentation index (AIX).

RESULTS

Patients were categorized upon the duration of disease, severity of skin involvement (PASI-Ps), individual pain as reflected by the VAS (PsA), CRP values, and history of treatment with one or more biologicals. Regarding the eEPC system, no significant differences were observed between the respective categories. Correlation analyses between parameters of vascular stiffness (PWV and AIX) and patterns of colony formation/circulating eEPCs did not show any correlation at all.

CONCLUSION

Parameters of vascular stiffness are not significantly deteriorated in Ps/PsA. Thus, pulse wave analysis may not be suitable for CVR assessment in certain autoimmune-mediated diseases. Regenerative activity of the eEPC system/circulating eEPC numbers are not altered in Ps/PsA. One may conclude that malfunctions of the eEPC are not substantially involved in perpetuating the micro-/macrovascular alterations in Ps/PsA.

Cerebral MR oximetry during acetazolamide augmentation: Beyond cerebrovascular reactivity in hemodynamic failure

BACKGROUND

Oxygen extraction fraction (OEF) elevation predicts increased ischemic stroke incidence among patients with carotid steno-occlusive disease, and can be estimated from quantitative susceptibility mapping (QSM) MRI.

PURPOSE

To explore QSM oximetry during acetazolamide (ACZ) challenge, hypothesizing that detectable OEF alterations will reflect hemodynamic compromise in unilateral cerebrovascular disease (CVD) patients.

STUDY TYPE

Retrospective.

SUBJECTS

Fourteen unilateral CVD patients, and 24 healthy controls (HC).

FIELD STRENGTH/SEQUENCE

Multiecho gradient echo (GRE) and T₁ -weighted images at 3T.

ASSESSMENT

We constructed QSM images and R2* maps from multiecho GRE images. QSM-OEF maps were generated from the susceptibility difference between venous blood and background brain tissue. Intrasubject diseased/contralateral hemisphere OEF ratios in the middle cerebral artery (MCA) territories were calculated. Intravascular susceptibility in the straight sinus (SS) and MCA was also measured.

STATISTICAL TESTS

The result significance was determined using t-tests and Pearson's correlation.

RESULTS

Mean and standard deviation for the patient diseased/contralateral OEF ratios were 1.15 ± 0.14 at baseline and 1.23 ± 0.17 post-ACZ. Disease group R2* ratios were 0.95 ± 0.05 at baseline and 1.03 ± 0.08 post-ACZ. Left/right OEF and R2* ratios for the HC group were 0.98 ± 0.06 and 0.99 ± 0.038, respectively. Susceptibility (ppb) in the SS and MCA in patients was 162.63 ± 35.4 and -22.33 ± 13.70, respectively, at baseline, 124.56 ± 37.43 and -19.27 ± 23.14 post-ACZ. The HC group SS and MCA susceptibility was 146.10 ± 24.79 and -19.59 ± 12.37, respectively. Patient group OEF ratios were greater than 1.0 before and after ACZ challenge (P < 0.01 and < 0.001, respectively, one-sample t-test), and were greater than HC ratios (P < 0.001 unpaired t-test). OEF and R2* ratios increased from baseline to post-ACZ (P = 0.024, 0.004, respectively, paired t-test). Detectable blood oxygenation change was confirmed by finding SS susceptibility decreased from baseline to post-ACZ (P < 0.001, paired t-test), while MCA susceptibility did not change significantly (P = 0.67, paired t-test).

DATA CONCLUSION

These results suggest QSM is sensitive to dynamic OEF modulation during hemodynamic augmentation.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:175-182.

Multi-locus sequence typing of African swine fever viruses from endemic regions of Kenya and Eastern Uganda (2011-2013) reveals rapid B602L central variable region evolution

The central variable region (CVR) within the B602L gene of the African swine fever virus (ASFV) is highly polymorphic within the 23 ASFV genotypes defined by sequencing of the C-terminal end of the p72 locus. Sequencing the p54 gene further discriminates ASFV genotypes that are conserved at the p72 locus. Variation in the thymidine kinase locus is a novel additional tool for ASFV genotyping whose application for this purpose is described for the first time herein. We evaluated genetic variation at these four polymorphic loci in 39 ASFV isolates obtained from outbreaks in Kenya and a region of Eastern Uganda between 2011 and 2013. Analysis of the p72 and p54 loci revealed high genetic conservation among these isolates; all clustered within p72 genotype IX and were similar to isolates associated with earlier outbreaks in East Africa. The thymidine kinase gene of the Kenyan isolates in this study were distinct relative to Southern African isolates and synonymous substitutions were observed among viruses from central Kenya. Analysis of the CVR within the B602L gene revealed two previously unknown polymorphisms that were restricted to Western Kenya and Eastern Uganda. A novel variant was revealed within CVR subgroup XXIV and a novel CVR subgroup XXIVa that contains tetrameric repeat F which has previously only been associated with p72 genotype I, was also identified for the first time in East Africa. Phylogeographic analysis of isolates based on CVR polymorphisms revealed rapid evolution and dissemination of variants present within ASFV genotype IX in East Africa.

Quantitative cerebrovascular pathology in a community-based cohort of older adults

Cerebrovascular disease, especially small vessel pathology, is the leading comorbidity in degenerative disorders. We applied arterial spin labeling and cerebrovascular reserve (CVR) imaging to quantify small vessel disease and study its effect on cognitive symptoms in nondemented older adults from a community-based cohort. We evaluated baseline cerebral blood flow (CBF) using arterial spin labeling and percent signal change as a marker of CVR using blood-oxygen level-dependent imaging following a breath-hold stimulus. Measurements were performed in and near white matter hyperintensities, which are currently the standard to assess severity of vascular pathology. We show that similar to other studies (1) CBF and CVR are markedly reduced in the hyperintensities as well as in the tissue surrounding them, indicating susceptibility to infarction; (2) low CBF and CVR are significantly correlated with poor cognitive performance; and (3) in addition, compared to a 58.4% reduction in CBF, larger exhaustion (79.3%) of CVR was observed in the hyperintensities with a faster, nonlinear rate of decline. We conclude that CVR may be a more sensitive biomarker of small vessel disease than CBF.

Cerebrovascular Reactivity and Intellectual Outcome in Childhood Stroke With Transient Cerebral Arteriopathy

BACKGROUND

Hypercapnic-challenge blood oxygen level-dependent magnetic resonance imaging cerebrovascular reactivity (CVR), measures the regional perfusion response to altered carbon dioxide. CVR correlates with the tissue-level microvascular dysfunction and ischemic risk. Among children with arterial ischemic stroke, transient cerebral arteriopathy (TCA) is a frequent, nonprogressive unilateral intracranial arteriopathy, which typically results in basal ganglia infarction and chronic cerebral artery stenosis. Therefore TCA provides a model for studying the consequences of chronic nonprogressive stenosis using CVR and intellectual outcome. We hypothesized that children with TCA and chronic nonprogressive intracranial artery stenosis have impaired CVR distal to the stenosis and associated cognitive impairment.

METHODS

We studied children with a prior diagnosis of TCA as defined by infarction limited to the basal ganglia, internal capsule, or both; and significant (greater than 50% diameter) residual stenosis of the supraclinoid internal carotid artery, its proximal branches or both. All children had CVR, intellectual function, and infarct volumes quantified.

RESULTS

We performed CVR studies in five children at mean 8.96 years (3.33 to 14.58 years) poststroke. Impaired CVR was limited to the infarct zone and adjacent white matter in most children. Intellectual function was broadly average in all but one subject.

CONCLUSIONS

In children with typical TCA, ipsilateral cortical CVR and intellectual function seem to be preserved despite persistent arterial stenosis in the majority. These findings suggest that chronic revascularization strategies in these children may not be indicated and require further exploration in a larger cohort of children.

Genetic Assessment of African Swine Fever Isolates Involved in Outbreaks in the Democratic Republic of Congo between 2005 and 2012 Reveals Co-Circulation of p72 Genotypes I, IX and XIV, Including 19 Variants

African swine fever (ASF) is a devastating disease of domestic pigs. It is a socioeconomically important disease, initially described from Kenya, but subsequently reported in most Sub-Saharan countries. ASF spread to Europe, South America and the Caribbean through multiple introductions which were initially eradicated—except for Sardinia—followed by re‑introduction into Europe in 2007. In this study of ASF within the Democratic Republic of the Congo, 62 domestic pig samples, collected between 2005–2012, were examined for viral DNA and sequencing at multiple loci: C-terminus of the B646L gene (p72 protein), central hypervariable region (CVR) of the B602L gene, and the E183L gene (p54 protein). Phylogenetic analyses identified three circulating genotypes: I (64.5% of samples), IX (32.3%), and XIV (3.2%). This is the first evidence of genotypes IX and XIV within this country. Examination of the CVR revealed high levels of intra-genotypic variation, with 19 identified variants.

Invalidation of fMRI experiments secondary to neurovascular uncoupling in patients with cerebrovascular disease

PURPOSE

Blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is a technique used to infer neuronal activity from the observed changes in blood flow. Cerebrovascular reactivity (CVR) is the ability of arterioles to increase blood flow in response to vasodilatory stimulus. We hypothesize that in areas of disease where there is exhausted vascular reserve and impaired CVR there will be diminished blood flow response following neuronal activation, and that these areas would appear as false-negative tests on BOLD fMRI.

MATERIALS AND METHODS

Patients with steno-occlusive disease and unilateral hemodynamic impairment received a standardized hypercapnic stimuli while being imaged with BOLD fMRI to generate CVR maps. These were compared to traditional BOLD fMRI maps of neuronal activation in the motor cortex in response to a motor task.

RESULTS

Neuronal activation from the motor task was found to be linearly correlated with CVR (n = 11 patients, R = 0.82). Regions with positive (normal) CVR showed positive activation on BOLD fMRI, while regions with negative CVR had attenuated neuronal activation on BOLD fMRI.

CONCLUSION

In areas with cerebrovascular disease where CVR is impaired, there is uncoupling of neuronal activation and blood flow that confounds traditional BOLD fMRI. CVR mapping is a noninvasive MRI-based imaging technique that can provide information about the vascular reactivity of the brain that is important to consider when interpreting traditional BOLD fMRI studies.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1448-1455.

Identification of a New Genotype of African Swine Fever Virus in Domestic Pigs from Ethiopia

African swine fever (ASF) is an important emerging transboundary animal disease (TAD), which currently has an impact on many countries in Africa, Eastern Europe, the Caucasus and the Russian Federation. The current situation in Europe shows the ability of the virus to rapidly spread, which stands to threaten the global swine industry. At present, there is no viable vaccine to minimize spread of the disease and stamping out is the main source of control. In February 2011, Ethiopia had reported its first suspected outbreaks of ASF. Genomic analyses of the collected ASF virus (ASFV) strains were undertaken using 23 tissue samples collected from domestic swine in Ethiopia from 2011 to 2014. The analysis of Ethiopian ASFVs partial p72 gene sequence showed the identification of a new genotype, genotype XXIII, that shares a common ancestor with genotypes IX and X, which comprise isolates circulating in Eastern African countries and the Republic of Congo. Analysis of the p54 gene also followed the p72 pattern and the deduced amino acid sequence of the central variable region (CVR) of the B602L gene showed novel tetramer repeats not previously characterized.

Fourier modeling of the BOLD response to a breath-hold task: Optimization and reproducibility

Cerebrovascular reactivity (CVR) reflects the capacity of blood vessels to adjust their caliber in order to maintain a steady supply of brain perfusion, and it may provide a sensitive disease biomarker. Measurement of the blood oxygen level dependent (BOLD) response to a hypercapnia-inducing breath-hold (BH) task has been frequently used to map CVR noninvasively using functional magnetic resonance imaging (fMRI). However, the best modeling approach for the accurate quantification of CVR maps remains an open issue. Here, we compare and optimize Fourier models of the BOLD response to a BH task with a preparatory inspiration, and assess the test-retest reproducibility of the associated CVR measurements, in a group of 10 healthy volunteers studied over two fMRI sessions. Linear combinations of sine-cosine pairs at the BH task frequency and its successive harmonics were added sequentially in a nested models approach, and were compared in terms of the adjusted coefficient of determination and corresponding variance explained (VE) of the BOLD signal, as well as the number of voxels exhibiting significant BOLD responses, the estimated CVR values, and their test-retest reproducibility. The brain average VE increased significantly with the Fourier model order, up to the 3rd order. However, the number of responsive voxels increased significantly only up to the 2nd order, and started to decrease from the 3rd order onwards. Moreover, no significant relative underestimation of CVR values was observed beyond the 2nd order. Hence, the 2nd order model was concluded to be the optimal choice for the studied paradigm. This model also yielded the best test-retest reproducibility results, with intra-subject coefficients of variation of 12 and 16% and an intra-class correlation coefficient of 0.74. In conclusion, our results indicate that a Fourier series set consisting of a sine-cosine pair at the BH task frequency and its two harmonics is a suitable model for BOLD-fMRI CVR measurements based on a BH task with preparatory inspiration, yielding robust estimates of this important physiological parameter.

Accuracy and precision of pseudo-continuous arterial spin labeling perfusion during baseline and hypercapnia: a head-to-head comparison with ¹⁵O H₂O positron emission tomography

Measurements of the cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) provide useful information about cerebrovascular condition and regional metabolism. Pseudo-continuous arterial spin labeling (pCASL) is a promising non-invasive MRI technique to quantitatively measure the CBF, whereas additional hypercapnic pCASL measurements are currently showing great promise to quantitatively assess the CVR. However, the introduction of pCASL at a larger scale awaits further evaluation of the exact accuracy and precision compared to the gold standard. (15)O H₂O positron emission tomography (PET) is currently regarded as the most accurate and precise method to quantitatively measure both CBF and CVR, though it is one of the more invasive methods as well. In this study we therefore assessed the accuracy and precision of quantitative pCASL-based CBF and CVR measurements by performing a head-to-head comparison with (15)O H₂O PET, based on quantitative CBF measurements during baseline and hypercapnia. We demonstrate that pCASL CBF imaging is accurate during both baseline and hypercapnia with respect to (15)O H₂O PET with a comparable precision. These results pave the way for quantitative usage of pCASL MRI in both clinical and research settings.

Functional imaging of cerebral perfusion

The functional imaging of perfusion enables the study of its properties such as the vasoreactivity to circulating gases, the autoregulation and the neurovascular coupling. Downstream from arterial stenosis, this imaging can estimate the vascular reserve and the risk of ischemia in order to adapt the therapeutic strategy. This method reveals the hemodynamic disorders in patients suffering from Alzheimer's disease or with arteriovenous malformations revealed by epilepsy. Functional MRI of the vasoreactivity also helps to better interpret the functional MRI activation in practice and in clinical research.

Effective surgical revascularization improves cerebral hemodynamics and resolves headache in pediatric Moyamoya disease

BACKGROUND

Headache is one of the major clinical presentations in pediatric Moyamoya disease. However, the clinical features and underlying mechanisms are not fully understood. This study aimed to clarify the clinical feature of headache in pediatric Moyamoya disease and the effect of surgical revascularization.

METHODS

This study included 29 pediatric patients who underwent superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and indirect bypass for Moyamoya disease. Their medical records were precisely evaluated to identify the clinical features of their headache. The findings on magnetic resonance imaging, positron emission tomography, and single-photon emission computed tomography also were analyzed.

RESULTS

Preoperative headache was documented in 11 (38%) of 29 patients. The majority of them complained of severe headache in the frontal or temporal region in the morning. Headache was significantly related to more advanced disease stage and to the decreases in cerebral blood flow and its reactivity to acetazolamide. Surgical revascularization completely resolved headache in all 11 patients.

CONCLUSIONS

These findings strongly suggest that disturbed cerebral hemodynamics may play key roles in developing severe headache in pediatric Moyamoya disease. STA-MCA anastomosis and encephalo-duro-myo-arterio-pericranial synangiosis may be effective procedures to rapidly resolve headache by widely supplying collateral blood flow to the operated hemispheres.