Estimation of cerebrovascular reactivity amplitude and lag using breath-holding fMRI and the global BOLD signal: Application in diabetes and hypertension.

In this work, we demonstrate a data-driven approach for estimating cerebrovascular reactivity (CVR) amplitude and lag from breathhold (BH) fMRI data alone. Our approach employs a frequency-domain approach that is independent of external recordings. CVR amplitude is estimated from the BOLD frequency spectrum and CVR lag is estimated from the Fourier phase using the global-mean BOLD signal as reference. Unlike referencing to external recordings, these lags are specific to the brain. We demonstrated our method in detecting regional CVR amplitude and lag differences across healthy (CTL), hypertensive (HT) and hypertension-plus-type-2-diabetes (HT + DM) groups of similar ages and sex ratios, with a total N of 49. We found CVR amplitude to be significantly higher in CTL compared to HT + DM, with minimal difference between CTL and HT. Also, voxelwise CVR lag estimated in the Fourier domain is a more sensitive marker of vascular dysfunction than CVR amplitude. CVR lag in HT is significantly shorter than in CTL, with minimal difference between CTL and HT + DM. Our results support the importance of joint CVR amplitude and lag assessments in clinical applications.

Multiplex PCR Approach for Rapid African Swine Fever Virus Genotyping.

African swine fever virus (ASFV) has been spreading through Europe, Asia, and the Caribbean after its introduction in Georgia in 2007 and, due to its particularly high mortality rate, poses a continuous threat to the pig industry. The golden standard to trace back the ASFV is whole genome sequencing, but it is a cost and time-intensive methodology. A more efficient way of tracing the virus is to amplify only specific genomic regions relevant for genotyping. This is mainly accomplished by amplifying single amplicons by PCR followed by Sanger sequencing. To reduce costs and processivity time, we evaluated a multiplex PCR based on the four primer sets routinely used for ASFV genotyping (B646L, E183L, B602L, and intergenic I73R-I329L), which was followed by Nanopore ligation-based amplicon sequencing. We show that with this protocol, we can genotype ASFV DNA originating from different biological matrices and correctly classify multiple genotypes and strains using a single PCR reaction. Further optimization of this method can be accomplished by adding or swapping the primer sets used for amplification based on the needs of a specific country or region, making it a versatile tool that can speed up the processing time and lower the costs of genotyping during ASFV outbreaks.

BOLD Cerebrovascular Reactivity and NOVA Quantitative MR Angiography in Adult Patients with Moyamoya Vasculopathy Undergoing Cerebral Bypass Surgery.

Revascularization surgery for the symptomatic hemisphere with hemodynamic impairment is effective for Moyamoya vasculopathy patients. However, careful patient selection is crucial and ideally supported by advanced quantitative hemodynamic imaging. Recently, blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR) and quantitative magnetic resonance angiography with non-invasive optimal vessel analysis (qMRA-NOVA) have gained prominence in assessing these patients. This study aims to present the results of BOLD-CVR and qMRA-NOVA imaging along with the changes in cerebral hemodynamics and flow status following flow augmentation with superficial temporal artery-middle cerebral artery (STA-MCA) bypass in our Moyamoya vasculopathy patient cohort. Symptomatic patients with Moyamoya vasculopathy treated at the Clinical Neuroscience Center of the University Hospital Zurich who underwent hemodynamic and flow imaging (BOLD-CVR and qMRA-NOVA) before and after bypass were included in the analysis. Reduced hemispheric volume flow rates, as well as impaired BOLD-CVR, were measured in all 12 patients with Moyamoya vasculopathy before STA-MCA bypass surgery. Following the surgical procedure, post-operative BOLD-CVR demonstrated a non-significant increase in BOLD-CVR values within the revascularized, symptomatic middle cerebral artery territory and cerebral hemisphere. The results of the statistical tests should be viewed as indicative due to the small sample size. Additionally, post-operative qMRA-NOVA revealed a significant improvement in the hemispheric volume flow rate of the affected hemisphere due to the additional bypass flow rate. Our findings affirm the presence of hemodynamic and flow impairments in the symptomatic hemisphere of the Moyamoya vasculopathy patients. Bypass surgery proves effective in improving both BOLD-CVR impairment and the hemispheric volume flow rate in our patient cohort.

Association of Prenatal Congenital Lung Malformation Volume Ratio to Postnatal Computed Tomography Characteristics.

INTRODUCTION: Congenital lung malformations (CLMs) are diverse and readily diagnosed on prenatal ultrasound. Postnatal computed tomography (CT) characteristics, including volume, are used in centers for the clinical decision-making of asymptomatic CLM. We aim to evaluate the relationship of prenatal CLM volume ratio (CVR) to postnatal CT characteristics by suspected prenatal diagnosis and postnatal radiological diagnosis. METHODS: We performed a single-center retrospective review of all patients evaluated with prenatally diagnosed CLM (May 2015-December 2022). Demographics, prenatal imaging findings at initial evaluation, and postnatal radiological diagnosis/imaging findings were analyzed with descriptive statistics. Pairwise correlation coefficient tests were performed to analyze the correlation between prenatal CVR and postnatal CT lesion size stratified by diagnosis. RESULTS: Of 123 patients referred and evaluated, suspected prenatal diagnoses consisted of 68 bronchial atresia (BA), 20 intralobar bronchopulmonary sequestration (iBPS), 20 extralobar bronchopulmonary sequestration (eBPS), and nine congenital pulmonary airway malformation (CPAM). Postnatal radiological diagnoses consisted of 53 BA, 22 iBPS, 14 eBPS, and 20 CPAM. Overall correlation coefficient of prenatal CVR to postnatal CT lesion size volume was 0.56. By suspected prenatal diagnosis, correlation coefficients were 0.61 (BA), 0.59 (iBPS), 0.29 (eBPS), and 0.51 (CPAM). For postnatal radiological diagnosis, correlation coefficients were 0.58 (BA), 0.56 (iBPS), 0.33 (eBPS), and 0.62 (CPAM). CONCLUSIONS: Our results indicate that initial CVR is overall consistent with the postnatal CT lesion size. This correlation is present in suspected prenatal diagnoses of BA and iBPS and postnatal radiological diagnoses of BA, iBPS, and CPAM. Additional studies analyzing long-term follow-up should be conducted to specify the safety of patients who undergo observation rather than surgical intervention.

The effect of pulmonary rehabilitation on cardiovascular risk, oxidative stress and systemic inflammation in patients with COPD.

PURPOSE: Chronic obstructive pulmonary disease (COPD) is a leading cause of death, and cardiovascular (CV) comorbidities play a role. Evidence of the pulmonary rehabilitation (PR) effect in reducing the CV risk (CVR) in COPD patients is limited. In this study, we aimed to determine the impact of an 8-week PR program (PRP) on the CVR of the overall population and to compare the impact on the exacerbator versus non-exacerbator patients. PATIENTS AND METHODS: This was a prospective study that included adults who had post-bronchodilator forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) (FEV1/FVC) ratio <70 % and FEV1 <80 % predicted, had quit smoking for at least 1 year and had a history of tobacco consumption greater than 10 packs/year, and were clinically stable in the last 8 weeks. Pre- and post-PRP assessments included respiratory function evaluation, laboratory tests, and exercise capacity assessment (6-min walking test [6MWT]). CVR was assessed using different risk prediction models. RESULTS: A total of 50 patients (28 exacerbators and 22 non-exacerbators) completed the PRP (median age: 64.5 years, men: 72 %; arterial hypertension: 70 %, dyslipidemia: 30 %, diabetes: 20 %; CV disease (CVD): 24 %. After the PRP, exacerbator patients showed a significant decrease in the CVR calculated by the COPDCoRi model (p < 0.001); patients with ≥30-m increase on the 6MWT showed statistically significant lower levels of glucose (p = 0.004), HbA1c (p = 0.004) and BODE index score (p = 0.026) compared to patients with <30-m increase. CONCLUSIONS: PR reduced certain modifiable CVR factors and CVD risk, especially in exacerbator patients.

[Nonspecific craniovertebral spondylitis]. / Nespetsificheskie spondility kraniovertebral'noi oblasti.

OBJECTIVE: To analyze surgical strategy for nonspecific spondylitis of the craniovertebral region (CVR) taking into account clinical features and morphological signs of disease. MATERIAL AND METHODS: Eight patients with nonspecific spondylitis of CVR underwent surgery (4 women and 4 men aged 31-75 years). Three patients had pain syndrome, 5 ones - conduction disorders. Combined interventions were performed in 5 patients with neurological disorders. Of these, 3 patients underwent transoral decompression with subsequent occipitospondylodesis. In other cases, stages of surgical treatment were reverse. Four patients underwent simultaneous interventions, 1 patient - with 7-day interval. Patients with pain syndrome underwent occipitospondylodesis. RESULTS: In all patients, postoperative VAS score of pain syndrome decreased by 5-7 points (mean 5.5). Among 5 patients with conduction symptoms, regression of neurological disorders 1 year after surgery was achieved in 2 cases, and complete recovery was observed in 3 patients (Frankel E). In all cases, examination confirmed relief of inflammatory process and no compression of the spinal cord and medulla oblongata. One patient had a dehiscence of the wound edges of posterior pharyngeal wall, and another one had implant fracture in 3 years after surgery. CONCLUSION: Active surgical approach is reasonable for nonspecific spondylitis of CVR. Craniocervical fixation eliminates pain and risk of neurological complications following atlantoaxial instability. Conduction disorders require simultaneous transoral decompression and occipitospondylodesis in patients with nonspecific purulent craniovertebral lesions. Impaired head tilt complicates transoral stage. In this regard, it is more rational to carry out craniocervical fixation at the last stage.

Comparison of Echocardiography and Myocardial Scintigraphy to Detect Cancer Therapy-Related Cardiovascular Toxicity in Breast Cancer Patients.

The mortality rate of cancer patients has been decreasing; however, patients often suffer from cardiac disorders due to chemotherapy or other cancer therapies (e.g., cancer-therapy-related cardiovascular toxicity (CVR-CVT)). Therefore, the field of cardio-oncology has drawn more attention in recent years. The first European Society of Cardiology (ESC) guidelines on cardio-oncology was established last year. Echocardiography is the gold standard for the diagnosis of CVR-CVT, but many breast cancer patients are unable to undergo echocardiography due to their surgery wounds or anatomical reasons. We performed a study to evaluate the usefulness of myocardial scintigraphy using Iodine-123 ß-methyl-P-iodophenyl-pentadecanoic acid (123I-BMIPP) in comparison with echocardiography and published the results in the Journal of Imaging last year. This is the secondary analysis following our previous study. A total of 114 breast cancer patients who received chemotherapy within 3 years underwent echocardiography, as well as Thallium (201Tl) and 123I-BMIPP myocardial perfusion and metabolism scintigraphy. The ratio of isotope uptake reduction was scored by Heart Risk View-S software (Nihon Medi-Physics). The scores were then compared with the echocardiography parameters. All the patients' charts and data from January 2022 to November 2023 were reviewed for the secondary analysis. Echocardiogram parameters were obtained from 99 patients (87% of total patients). No correlations were found between the echocardiography parameters and Heart Risk View-S scores of 201Tl myocardial perfusion scintigraphy, nor those of the BMIPP myocardial metabolism scintigraphy. In total, 8 patients out of 114 (7.0%) died within 22 months, while 3 patients out of 26 CVR-CVT patients (11.5%) died within 22 months. Evaluation by echocardiography was sometimes difficult to perform on breast cancer patients. However, other imaging modalities, including myocardial scintigraphy, cannot serve as alternatives to echocardiography. Cardiac scintigraphy detects circulation disorder or metabolism disorder in the myocardium; therefore, it should be able to reveal myocardial damage to some extent. The mortality rate of breast cancer patients was higher with CVR-CVT. A new modality to detect CVR-CVT besides echocardiography can possibly be anticipated for patients who cannot undergo echocardiography.

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.

Management and Outcomes of Patients With High-Risk (Congenital Lung Malformation Volume Ratio≥ 1.6) Congenital Lung Malformations.

INTRODUCTION: Congenital lung malformations (CLMs) have a variable natural history. Larger lesions with CLM volume ratio (CVR) ≥ 1.6 are associated with hydrops and fetal mortality. The purpose of this study is to describe the management and outcomes of high-risk (CVR ≥ 1.6) CLM patients. METHODS: A retrospective cohort study was performed for all fetuses evaluated between May 2015 and May 2022. Demographics, prenatal imaging factors, prenatal and postnatal treatment, and outcomes were collected. Descriptive statistics were used to compare the cohorts. RESULTS: Of 149 fetal CLM patients referred to our fetal center, 21/149 (14%) had CVR ≥ 1.6. One CLM patient had intrauterine fetal demise, and 2 patients were lost to follow-up. Of the remaining 18 patients, 11/18 (67%) received maternal steroids. Seven out of 18 patients (39%) underwent resection at the time of delivery with 1/7 (14%) undergoing exutero intrapartum treatment (EXIT)-to-resection, 5/7 (71%) undergoing EXIT-to-exteriorization-to-resection, and 1/7 (14%) undergoing a coordinated delivery to resection; among those undergoing resection, there were 2 fatalities (28.5%). Seven out of 18 (39%) patients required urgent neonatal open lobectomies, and the remaining 4/18 (22%) patients underwent elective thoracoscopic lobectomies with no mortality. CONCLUSIONS: The natural history and outcomes of severe CLM patients remain highly variable. The EXIT-to-exteriorization-to-resection procedure may be a safe and effective approach for a subset of CLM patients with persistent symptoms of mass effect and severe mediastinal shift due to the observed decreased operative time requiring placental support observed in our study.

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.

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.

Blood Oxygenation Level-Dependent Cerebrovascular Reactivity-Derived Steal Phenomenon May Indicate Tissue Reperfusion Failure After Successful Endovascular Thrombectomy.

In acute ischemic stroke due to large-vessel occlusion (LVO), the clinical outcome after endovascular thrombectomy (EVT) is influenced by the extent of autoregulatory hemodynamic impairment, which can be derived from blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR). BOLD-CVR imaging identifies brain areas influenced by hemodynamic steal. We sought to investigate the presence of steal phenomenon and its relationship to DWI lesions and clinical deficit in the acute phase of ischemic stroke following successful vessel recanalization.From the prospective longitudinal IMPreST (Interplay of Microcirculation and Plasticity after ischemic Stroke) cohort study, patients with acute ischemic unilateral LVO stroke of the anterior circulation with successful endovascular thrombectomy (EVT; mTICI scale ≥ 2b) and subsequent BOLD-CVR examination were included for this analysis. We analyzed the spatial correlation between brain areas exhibiting BOLD-CVR-associated steal phenomenon and DWI infarct lesion as well as the relationship between steal phenomenon and NIHSS score at hospital discharge.Included patients (n = 21) exhibited steal phenomenon to different extents, whereas there was only a partial spatial overlap with the DWI lesion (median 19%; IQR, 8-59). The volume of steal phenomenon outside the DWI lesion showed a positive correlation with overall DWI lesion volume and was a significant predictor for the NIHSS score at hospital discharge.Patients with acute ischemic unilateral LVO stroke exhibited hemodynamic steal identified by BOLD-CVR after successful EVT. Steal volume was associated with DWI infarct lesion size and with poor clinical outcome at hospital discharge. BOLD-CVR may further aid in better understanding persisting hemodynamic impairment following reperfusion therapy.

Convolutional Neural Networks to Assess Steno-Occlusive Disease Using Cerebrovascular Reactivity.

Cerebrovascular Reactivity (CVR) is a provocative test used with Blood oxygenation level-dependent (BOLD) Magnetic Resonance Imaging (MRI) studies, where a vasoactive stimulus is applied and the corresponding changes in the cerebral blood flow (CBF) are measured. The most common clinical application is the assessment of cerebral perfusion insufficiency in patients with steno-occlusive disease (SOD). Globally, millions of people suffer from cerebrovascular diseases, and SOD is the most common cause of ischemic stroke. Therefore, CVR analyses can play a vital role in early diagnosis and guiding clinical treatment. This study develops a convolutional neural network (CNN)-based clinical decision support system to facilitate the screening of SOD patients by discriminating between healthy and unhealthy CVR maps. The networks were trained on a confidential CVR dataset with two classes: 68 healthy control subjects, and 163 SOD patients. This original dataset was distributed in a ratio of 80%-10%-10% for training, validation, and testing, respectively, and image augmentations were applied to the training and validation sets. Additionally, some popular pre-trained networks were imported and customized for the objective classification task to conduct transfer learning experiments. Results indicate that a customized CNN with a double-stacked convolution layer architecture produces the best results, consistent with expert clinical readings.

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.

Generating dynamic carbon-dioxide traces from respiration-belt recordings: Feasibility using neural networks and application in functional magnetic resonance imaging.

Introduction: In the context of functional magnetic resonance imaging (fMRI), carbon dioxide (CO2) is a well-known vasodilator that has been widely used to monitor and interrogate vascular physiology. Moreover, spontaneous fluctuations in end-tidal carbon dioxide (PETCO2) reflects changes in arterial CO2 and has been demonstrated as the largest physiological noise source for denoising the low-frequency range of the resting-state fMRI (rs-fMRI) signal. However, the majority of rs-fMRI studies do not involve CO2 recordings, and most often only heart rate and respiration are recorded. While the intrinsic link between these latter metrics and CO2 led to suggested possible analytical models, they have not been widely applied. Methods: In this proof-of-concept study, we propose a deep-learning (DL) approach to reconstruct CO2 and PETCO2 data from respiration waveforms in the resting state. Results: We demonstrate that the one-to-one mapping between respiration and CO2 recordings can be well predicted using fully convolutional networks (FCNs), achieving a Pearson correlation coefficient (r) of 0.946 ± 0.056 with the ground truth CO2. Moreover, dynamic PETCO2 can be successfully derived from the predicted CO2, achieving r of 0.512 ± 0.269 with the ground truth. Importantly, the FCN-based methods outperform previously proposed analytical methods. In addition, we provide guidelines for quality assurance of respiration recordings for the purposes of CO2 prediction. Discussion: Our results demonstrate that dynamic CO2 can be obtained from respiration-volume using neural networks, complementing the still few reports in DL of physiological fMRI signals, and paving the way for further research in DL based bio-signal processing.

Dependence of resting-state-based cerebrovascular reactivity (CVR) mapping on spatial resolution.

Cerebrovascular reactivity (CVR) is typically assessed with a carbon dioxide (CO2) stimulus combined with BOLD fMRI. Recently, resting-state (RS) BOLD fMRI has been shown capable of generating CVR maps, providing a potential for broader CVR applications in neuroimaging studies. However, prior RS-CVR studies have primarily been performed at a spatial resolution of 3-4 mm voxel sizes. It remains unknown whether RS-CVR can also be obtained at high-resolution without major degradation in image quality. In this study, we investigated RS-CVR mapping based on resting-state BOLD MRI across a range of spatial resolutions in a group of healthy subjects, in an effort to examine the feasibility of RS-CVR measurement at high resolution. Comparing the results of RS-CVR with the maps obtained by the conventional CO2-inhalation method, our results suggested that good CVR map quality can be obtained at a voxel size as small as 2 mm isotropic. Our results also showed that, RS-CVR maps revealed resolution-dependent sensitivity. However, even at a high resolution of 2 mm isotropic voxel size, the voxel-wise sensitivity is still greater than that of typical task-evoked fMRI. Scan duration affected the sensitivity of RS-CVR mapping, but had no significant effect on its accuracy. These findings suggest that RS-CVR mapping can be applied at a similar resolution as state-of-the-art fMRI studies, which will broaden the use of CVR mapping in basic science and clinical applications including retrospective analysis of previously collected fMRI data.

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.

Severe Hypertriglyceridemia: A 10-Year Review in a Portuguese Hospital.

INTRODUCTION: Severe hypertriglyceridemia (SHTG) is a rare condition associated with serious complications, such as acute pancreatitis (AP), and the best treatment is still a matter of discussion. The aim of this study is to outline the demographics, management, and outcomes (recurrence and mortality) of complications in patients with SHTG. MATERIAL AND METHODS: A retrospective, observational, and analytical study was carried out by obtaining clinical data from the electronic health records of patients with SHTG admitted to the Internal and Intensive Medicine units from the 1st of January 2009 to the 31st of December 2020 in a university hospital. RESULTS: The cohort included 17 patients. The most common complication was AP (13/17 = 76.5%). Admission to the intensive care unit (ICU) was observed in 84.2%. Among patients with AP, the most commonly administered therapies were insulin (82.4%) and fibrates (76.5%). Plasmapheresis was used in 58.8%, and the criteria for using this technique were mainly based on clinical and laboratory abnormalities. There were no deaths. The readmission rate at 30 days was 36.3%. CONCLUSION: This study shows the morbidity profile associated with SHTG, with a high level of ICU admissions and also a high level of the use of plasmapheresis. In our population, this approach had good results, and this should be highlighted as there are no clear international guidelines for this intervention. Distinguishing between patients with familial chylomicronemia syndrome or with multifactorial chylomicronemia is important as recent specific therapy for lipoprotein lipase (LPL) genetic deficit is available. In the near future, the performance of a genetic study should be considered in patients with SHTG as an attempt to avoid the high recurrence rate of complications of this disease.

A dual-center validation of the PIRAMD scoring system for assessing the severity of ischemic Moyamoya disease.

Background: Prior Infarcts, Reactivity, and Angiography in Moyamoya Disease (PIRAMD) is a recently proposed imaging-based scoring system that incorporates the severity of disease and its impact on parenchymal hemodynamics in order to better support clinical management and evaluate response to intervention. In particular, PIRAMD may have merit in identifying symptomatic patients that may benefit most from revascularization. Our aim was to validate the PIRAMD scoring system. Methods: Patients with ischemic Moyamoya disease, who underwent catheter angiographic [modified Suzuki Score (mSS) and collateralization status], morphological MRI and a parenchymal hemodynamic evaluation with blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) at two transatlantic centers, were retrospectively included. The primary outcome was the presence of neurological symptoms. The diagnostic capacity of each PIRAMD feature alone was evaluated, as well as combined and the inter-institutional differences of each parameter were evaluated. Results: Seventy-two hemispheres of 38 patients were considered for analysis, of which 39 (54%) were classified as symptomatic. The presence of a prior infarct had the highest odds ratio [odds ratio (OR) =24; 95% CI: 6.7-87.2] for having neurological symptoms, followed by impaired CVR (OR =17; 95% CI: 5-62). No inter-institutional differences in the odds ratios or area under the curve (AUC) were found for any study parameter. The PIRAMD score had an AUC of 0.88 (95% CI: 0.80-0.96) with a similar AUC for the PIRAMD grading score. Conclusions: Our multicentric validation of the recently published PIRAMD scoring system was highly effective in rating the severity of ischemic Moyamoya disease with excellent inter-institutional agreement. Future studies should investigate the prognostic value of this novel imaging-based score in symptomatic patients with Moyamoya disease.

Impact of prenatal estimation of the risk of respiratory distress in neonates with congenital pulmonary malformations on the choice of delivery site.

BACKGROUND: The vast majority of prenatally diagnosed congenital pulmonary malformations (CPM) remain asymptomatic at birth. The maximal value of the CPM volume ratio (CVRmax) predicts the risk of neonatal respiratory distress (NRD), and should allow for better assessment of the level of expertise needed at the delivery site. AIM: This study evaluated the level of maternity units currently chosen for the delivery of CPMs, and determined the impact of the choice of delivery site based on the CVRmax, with a threshold of 0.4 cm2. METHODS: Data were extracted from the French prospective MALFPULM cohort, with inclusion between March 2015 and June 2018. RESULTS: The final study population consisted of 383 women. Deliveries in level 1 or 2 maternity units (n = 98, 25%) involved CPMs with lower CVRmax (p<0.001), causing fewer signs of prenatal compression (p = 0.025). Among the 62 children (16%) who presented with NRD, only seven (11%) were born in level 1 or 2 units (p = 0.0078). Choosing the maternity level according to the CVRmax would have increased the number of births in level 1 or 2 maternity hospitals by 70%. In these maternity units, the percentage of children with NRD would have increased from 8% in the actual distribution to 10% in the new strategy. CONCLUSION: Our results showed an overuse of level 3 maternity hospitals for the delivery of newborns with a prenatal diagnosis of CPM. The use of CVRmax should enable a reduction in the use of expertise centers without an adverse impact on newborns.