Journal of Neuroimaging最新文献

Background and Purpose

In recent years, there has been a growing interest in the study of resting neural networks in different neurological and mental disorders. While previous studies suggest that the default mode network (DMN) may be altered in dyscalculia, the study of resting-state networks in the development of numerical skills, especially in children with developmental dyscalculia (DD), is scarce and relatively recent. Based on this, this study examines differences in resting-state functional connectivity (rs-FC) data of children with DD using functional connectivity multivariate pattern analysis (fc-MVPA), a data-driven methodology that summarizes properties of the entire connectome.

Methods

We performed fc-MVPA on resting-state images of a sample composed of a group of children with DD (n = 19, 8.06 ± 0.87 years) and an age- and sex-matched control group of typically developing children (n = 23, 7.76 ± 0.46 years).

Results

Analysis of fc-MVPA showed significant differences between group connectivity profiles in two clusters allocated in both the right and left medial temporal gyrus. Post hoc effect size results revealed a decreased rs-FC between each temporal pole and the DMN in children with DD and an increased rs-FC between each temporal pole and the sensorimotor network.

Conclusions

Our results suggest an aberrant information flow between resting-state networks in children with DD, demonstrating the importance of these networks for arithmetic development.

Background and Purpose

Cerebral infarction remains an important cause of death or disability in patients with aneurysmal subarachnoid hemorrhage (SAH). The prevalence, trends, and outcomes of cerebral infarction in patients with aneurysmal SAH at a national level are not known.

Methods

We identified the proportion of patients who develop cerebral infarction (ascertained using validated methodology) among patients with aneurysmal SAH and annual trends using the Nationwide Inpatient Sample (NIS) from 2016 to 2021. We analyzed the effect of cerebral infarction on in-hospital mortality, routine discharge without palliative care (based on discharge disposition), poor outcome defined by the NIS SAH outcome measure, and length and costs of hospitalization after adjusting for potential confounders.

Results

A total of 35,305 (53.6%) patients developed cerebral infarction among 65,840 patients with aneurysmal SAH over a 6-year period. There was a trend toward an increase in the proportion of patients who developed cerebral infarction from 51.5% in 2016 to 56.1% in 2021 (p trend p<.001). Routine discharge was significantly lower (30.5% vs. 37.8%, odds ratio [OR] 0.82, 95% confidence interval [CI] 0.75-0.89, p<.001), and poor outcome defined by NIS-SAH outcome measure was significantly higher among patients with cerebral infarction compared with those without cerebral infarction (67.4% vs. 59.3%, OR 1.29, 95% CI 1.18-1.40, p<.001). There was no difference in in-hospital mortality (13.0% vs. 13.6%, OR 0.94, 95% CI 0.85-1.05, p = .30). The length of stay (median 18 days [interquartile range [IQR] 13-25] vs. 14 days [IQR 9-20]), coefficient 3.04, 95% CI 2.44-3.52 and hospitalization cost (median $96,823 vs. $71,311, coefficient 22,320, 95% CI 20,053-24,587) were significantly higher among patients who developed cerebral infarction compared with those who did not develop cerebral infarction.

Conclusions

Cerebral infarction was seen in 54% of the patients with a trend toward an increase in the affected proportion of patients with aneurysmal SAH. Patients with cerebral infarction had higher rates of adverse outcomes and required higher resources during hospitalization.

Background and Purpose

Ischemic strokes due to isolated posterior cerebral artery (PCA) occlusions represent 5% of all strokes but have significant impacts on patients’ quality of life, primarily due to visual deficits and thalamic involvement. Current guidelines for acute PCA occlusion management are sparse, and the prognostic value of perfusion imaging parameters remains underexplored.

Methods

We conducted a retrospective analysis of 32 patients with isolated PCA occlusions treated at Johns Hopkins Medical Institutions between January 2017 and March 2023. Patients underwent pretreatment perfusion imaging, with perfusion parameters analyzed using RAPID software. The primary outcome was short-term clinical outcome as measured by the National Institutes of Health Stroke Scale (NIHSS) at discharge.

Results

The median age of the cohort was 70 years, with 34% female and 66% male. Significant correlations were found between NIHSS at discharge and various perfusion parameters, including time-to-maximum (Tmax) >6 seconds (ρ = .55, p = .004), Tmax >8 seconds (ρ = .59, p = .002), Tmax >10 seconds (ρ = .6, p = .001), mismatch volume (ρ = .51, p = .008), and cerebral blood volume (CBV) < 34% (ρ = .59, p = .002).

Conclusions

Tmax and CBV volumes significantly correlated with discharge NIHSS with marginal superiority of Tmax >10 seconds and CBV <42% volumes. These findings suggest that CT and MR perfusion imaging can play a crucial role in the acute management of PCA strokes, though larger, standardized studies are needed to validate these results and refine imaging thresholds specific to posterior circulation infarcts.

Background and Purpose

The 3-dimensional cranial nerve imaging (CRANI) sequence may assist visualization of anatomical details of extraforaminal cranial nerves and aid in clinical diagnosis and preoperative planning. In this study, we investigated the feasibility of using a combined CRANI and magnetization-prepared rapid-acquisition gradient-echo (MPRAGE) imaging protocol to comprehensively identify trigeminal nerve projections.

Method

We evaluated the detection of distal regions of three branches of the ophthalmic nerve (V1), three branches of the maxillary nerve (V2), and five branches of the mandibular nerve (V3) in seven healthy adult subjects, with and without contrast injection. Nerve branches were rated on a 5-point scale by three observers. Interobserver reliability was studied using weighted kappa statistics and percentage agreement.

Results

Among V1 and V2 branches, the frontal nerve and infraorbital nerve were most successfully identified (average rating of 3.9, agreement >80%) in precontrast MPRAGE images. In V3 branches, lingual and inferior alveolar nerves were most successfully identified (average rating of 3.9, agreement >80%) in precontrast CRANI images, with an excellent average rating. In all cases except one, interobserver reliability was rated good to excellent. The buccal nerve was the only branch with a low average interobserver rating. Gadolinium contrast did not improve nerve segment visualization in our study. This may relate to the specific anatomic regions assessed, gadolinium dose, postcontrast image timing, and lack of pathology.

Conclusion

A combined CRANI and MPRAGE protocol can be combined to visualize distal branches of V1, V2, and V3 and has potential for clinical use.

Background and Purpose

Magnetic resonance imaging (MRI) is heavily relied upon for the diagnosis and monitoring of multiple sclerosis (MS), a chronic, demyelinating disease of the central nervous system. Serum biomarkers may serve as an accessible tool for increasing sensitivity, improving accessibility, corroborating symptoms, and providing additional data to guide clinical management. This scoping review investigates the current understanding of how the serum biomarker glial fibrillary acidic protein (sGFAP) relates to brain MRI metrics.

Methods

We adhered to the Joanna Briggs Institute methodology for scoping reviews and the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. The databases Medline (Ovid), Embase (Ovid), CINAHL (Ebsco), and Web of Science (University of British Columbia institutional access) were searched on August 24, 2023 using a combination of medical subject headings and keyword terms for the topic of serum biomarkers in MS.

Results

A total of 9880 articles were retrieved in total of which 6271 unique titles and abstracts were screened. Twelve of the 259 resultant papers contained sGFAP data and proceeded to extraction. It was found that lesion MRI metrics generally had a positive relationship with sGFAP, while gray matter and white matter metrics, including normal-appearing white matter, were related negatively or not at all.

Conclusions

These results highlight that while sGFAP may not be specific for MS, it may have utility for increasing sensitivity in postdiagnosis monitoring of MS progression.

Background and Purpose

This study sought to explore dynamic degree centrality (DC) variability in particular regions of the brain in patients with poststroke Broca aphasia (BA) using a resting-state functional magnetic resonance imaging (rs-fMRI) approach, comparing differences between Uyghur and Chinese BA patients.

Methods

This study investigated two factors, language and BA status, and divided patients into four groups: Uyghur aphasia patients (UA), Uyghur normal control subjects (UN), Chinese aphasia patients (CA), and Chinese normal subjects (CN) who underwent rs-fMRI analysis. Two-way analysis of variance (ANOVA) was used to calculate the comprehensive differences in dynamic DC among these four groups. Correlations between DC and language behavior were assessed with partial correlation analyses.

Results

Two-way ANOVA revealed comparable results for the results of pairwise comparisons of dynamic DC variability among the four groups in the right middle frontal gyrus/orbital part (ORBmid.R), right superior frontal gyrus/dorsolateral, and right precuneus (PCUN.R), with results as follows: UA < UN, CA > CN, UA < CA, and UN > CN (p < .05, with the exception of the p-values for UA and UN in superior frontal gyrus/dorsolateral). In contrast, the opposite results were observed for the right calcarine fissure and surrounding cortex (CAL.R, p < .05).

Conclusion

The observed enhancement of dynamic DC variability in ORBmid.R and PCUN.R among Chinese BA patients and in CAL.R in Uyghur BA patients may be attributable to language network restructuring. Overall, these results suggest that BA patients who use different language families may exhibit differences in the network mechanisms that characterize observed impairments of language function.

Epilepsy, affecting 0.5%-1% of the global population, presents a significant challenge with 30% of patients resistant to medical treatment. Temporal lobe epilepsy, a common cause of medically refractory epilepsy, is often caused by hippocampal sclerosis (HS). HS can be divided further by subtype, as defined by the International League Against Epilepsy (ILAE). Type 1 HS, the most prevalent form (60%-80% of all cases), is characterized by cell loss and gliosis predominantly in the subfields cornu ammonis (CA1) and CA4. Type 2 HS features cell loss and gliosis primarily in the CA1 sector, and type 3 HS features cell loss and gliosis predominantly in the CA4 subfield. This literature review evaluates studies on hippocampal subfields, exploring whether observable atrophy patterns from in vivo and ex vivo magnetic resonance imaging (MRI) scans correlate with histopathological examinations with manual or automated segmentation techniques. Our findings suggest only ex vivo 1.5 Tesla (T) or 3T MRI with manual segmentation or in vivo 7T MRI with manual or automated segmentations can consistently correlate subfield patterns with histopathologically derived ILAE-HS subtypes. In conclusion, manual and automated segmentation methods offer advantages and limitations in diagnosing ILAE-HS subtypes, with ongoing research crucial for refining hippocampal subfield segmentation techniques and enhancing clinical applicability.