AJNR. American journal of neuroradiology最新文献

Background and purpose: Neuropsychiatric complications of SARS-CoV-2 infection, also known as neurologic postacute sequelae of SARS-CoV-2 infection (NeuroPASC), affect 10%-60% of infected individuals. There is growing evidence that NeuroPASC is a multi system immune dysregulation disease affecting the brain. The behavioral manifestations of NeuroPASC, such as impaired processing speed, executive function, memory retrieval, and sustained attention, suggest widespread WM involvement. Although previous work has documented WM damage following acute SARS-CoV-2 infection, its involvement in NeuroPASC is less clear. We hypothesized that macrostructural and microstructural WM differences in NeuroPASC participants would accompany cognitive and immune system differences.

Materials and methods: In a cross-sectional study, we screened a total of 159 potential participants and enrolled 72 participants, with 41 asymptomatic controls (NoCOVID) and 31 NeuroPASC participants matched for age, sex, and education. Exclusion criteria included neurologic disorders unrelated to SARS-CoV-2 infection. Assessments included clinical symptom questionnaires, psychometric tests, brain MRI measures, and peripheral cytokine levels. Statistical modeling included separate multivariable regression analyses of GM/WM/CSF volume, WM microstructure, cognitive, and cytokine concentration between-group differences.

Results: NeuroPASC participants had larger cerebral WM volume than NoCOVID controls (β = 0.229; 95% CI: 0.017-0.441; t = 2.16; P = .035). The most pronounced effects were in the prefrontal and anterior temporal WM. NeuroPASC participants also exhibited higher WM mean kurtosis, consistent with ongoing neuroinflammation. NeuroPASC participants had more self-reported symptoms, including headache, and lower performance on measures of attention, concentration, verbal learning, and processing speed. A multivariate profile analysis of the cytokine panel showed different group cytokine profiles (Wald-type-statistic = 44.6, P = .046), with interferon (IFN)-λ1 and IFN-λ2/3 levels higher in the NeuroPASC group.

Conclusions: NeuroPASC participants reported symptoms of lower concentration, higher fatigue, and impaired cognition compatible with WM syndrome. Psychometric testing confirmed these findings. NeuroPASC participants exhibited larger cerebral WM volume and higher WM mean kurtosis than NoCOVID controls. These findings suggest that immune dysregulation could influence WM properties to produce WM volume increases and consequent cognitive effects and headaches. Further work will be needed to establish mechanistic links among these variables.

Background and purpose: Direct oral anticoagulants (DOAC) have rapidly replaced warfarin. Intracerebral hemorrhage (ICH) is known to be one of the most severe side effects of anticoagulant drugs. The black hole (BH) sign is reportedly a valid radiological sign for predicting hematoma expansion in acute ICH. Here, we hypothesized that the frequency of BH signs might differ between warfarin and DOAC treatment, and critically evaluated the clinical value of the BH sign in acute ICH under warfarin versus DOAC therapy.

Materials and methods: Patients with acute ICH under anticoagulant therapy were enrolled. Hematoma volumes were measured by ABC/2. Radiologists blinded to the clinical information determined the presence or absence of the BH sign on CT images. This study defined a more than 12.5 ml increase in hematoma volume as cases with "expanded hematoma".

Results: We analyzed 111 acute ICH patients under anticoagulant therapy. Among them, 21 patients were treated with antagonists in this cohort. Multivariate logistic regression analysis revealed that the presence of ventricular perforation (p=0.02; adjusted odds ratio (OR): 3.51, 95% confidence interval (CI): 1.32 - 10.2) and the BH sign (p<0.01; adjusted OR: 4.86, 95% CI: 1.73 - 14.3) were significantly different between expanded and non-expanded hematoma cases. Comparison of hematoma volume and the presence of the BH sign between warfarin and DOAC cases indicated significant differences in maximum hematoma volume (p=0.03) and presence of the BH sign (p<0.01). The increase in hematoma volume was significantly greater when the BH sign was present under warfarin therapy (p=0.05). In contrast, the increase in hematoma volume did not differ between cases with and without the BH sign in patients under DOAC therapy (p=0.14) CONCLUSIONS: The BH sign is a useful radiological signature to predict the expansion of acute ICH under anticoagulant therapy. ICH under warfarin tended to present the BH sign more frequently than that under DOAC. The results also showed that the BH sign is more reliable under warfarin than under DOAC therapy in ICH patients.

Abbreviations: AF = atrial fibrillation; BH = black hole; DOAC = direct oral anticoagulants; HU = Hounsfield Unit; ICH= intracerebral hemorrhage.

Background and purpose: The peak width of skeletonized mean diffusivity (PSMD) is a novel marker of small vessel disease. In this study, we aimed to investigate the presence of small vessel disease in patients with transient global amnesia (TGA) using the PSMD.

Materials and methods: We enrolled 75 patients newly diagnosed with TGA and included 65 age-and sex-matched healthy controls. Diffusion tensor imaging (DTI) was performed using a 3T magnetic resonance imaging scanner. We measured the PSMD based on DTI using the FSL program. This measure was compared between patients with TGA and healthy controls. Additionally, we conducted a correlation analysis to explore the relationship between PSMD and clinical factors.

Results: A significant difference in the PSMD between patients with TGA and healthy controls was observed. Patients with TGA exhibited higher a PSMD compared to healthy controls (2.297±0.232 vs. 2.188±0.216 ×10^-4 mm²/s, p=0.005). Additionally, patients with TGA but without any vascular risk factors, such as diabetes, hypertension or dyslipidemia, also exhibited higher a PSMD compared to healthy controls (2.278±0.253 vs. 2.188±0.216 ×10^-4 mm²/s, p=0.036). The PSMD positively correlated with age (r=0.248, p=0.032); however, it was not associated with duration of amnesia.

Conclusions: This finding underscores the feasibility of using PSMD as a marker for detecting small vessel diseases in patients with neurological disorders. Furthermore, our study also implies the presence of small vessel disease may be present in patients with TGA.

Abbreviations: TGA=transient global amnesia; TIA= transient ischemic attack; PSMD= peak width of skeletonized mean diffusivity; DTI= diffusion tensor imaging.

Background and purpose: Measurement of the mean upper cervical cord area (MUCCA) is an important biomarker in the study of neurodegeneration. However, dedicated high-resolution scans of the cervical spinal cord are rare in standard-of-care imaging due to timing and clinical usability. Most clinical cervical spinal cord imaging is sagittally acquired in 2D with thick slices and anisotropic voxels. As a solution, previous work describes high-resolution T1-weighted brain imaging for measuring the upper cord area, but this is still not common in clinical care.

Materials and methods: We propose using a zero-shot super-resolution technique, SMORE, already validated in the brain, to enhance the resolution of 2D-acquired scans for upper cord area calculations. To incorporate super-resolution in spinal cord analysis, we validate SMORE against high-resolution research imaging and in a real-world longitudinal data analysis.

Results: Super-resolved images reconstructed using SMORE showed significantly greater similarity to the ground truth than low-resolution images across all tested resolutions (p<0.001 for all resolutions in PSNR and MSSIM). MUCCA results from super-resolved scans demonstrate excellent correlation with high-resolution scans (r>0.973 for all resolutions) compared to low-resolution scans. Additionally, super-resolved scans are consistent between resolutions (r>0.969), an essential factor in longitudinal analysis. Compared to clinical outcomes such as walking speed or disease severity, MUCCA values from low-resolution scans have significantly lower correlations than those from high-resolution scans. Super-resolved results have no significant difference. In a longitudinal real-world dataset, we show that these super-resolved volumes can be used in conjunction with T1-weighted brain scans to show a significant rate of atrophy (-0.790, p=0.020 vs. -0.438, p=0.301 with low-resolution).

Conclusions: Super-resolution is a valuable tool for enabling large-scale studies of cord atrophy, as low-resolution images acquired in clinical practice are common and available.

Abbreviations: MS=multiple sclerosis; MUCCA=mean upper cervical cord; HR=high-resolution; LR=low-resolution; SR=superresolved; CSC=cervical spinal cord; PMJ=pontomedullary junction; MSSIM=mean structural similarity; PSNR=peak signal-to-noise ratio; EDSS=expanded disability status scale.

Background and purpose: Schizencephaly is a rare brain anomaly which is increasingly detected in utero. There are limited data on the etiology and outcomes in fetal schizencephaly to guide workup and counselling. We aim to determine the associated imaging findings, etiology, and outcomes in schizencephaly detected in utero.

Materials and methods: This retrospective cohort study included 22 fetuses with a total of 34 schizencephaly defects identified by keyword search of fetal MRI reports from 1996-2022 followed by image review. Follow-up fetal and postnatal imaging, when available, were reviewed. Data on demographics, etiology, and outcomes were extracted from the electronic medical record.

Results: The schizencephaly defect was open in 28/34, most common in the MCA territory (23/34), and commonly involved the frontal (16/34) lobe. Additional intracranial abnormalities were seen in all fetuses including other cortical malformations (CM, 13/22), abnormal posterior fossa (12/22), abnormal corpus callosum (10/20), and intraparenchymal hemorrhage (9/22).The cause of schizencephaly was classified as secondary (as evidenced by intraparenchymal hemorrhage at schizencephaly, monochorionic twin gestation, infection, or maternal/placental risk factor) in 64% (14/22), potentially genetic in 9% (2/22), and unknown in 27% (6/22). Among those liveborn (n=8), the following outcomes were observed: postnatal death (1/8), tube feeding (1/7), shunted hydrocephalus (1/7), epilepsy (4/7). Among those >1 year of age, cerebral palsy (4/5) and speech delay or intellectual disability (3/5) were common. CM remote from schizencephaly was associated with epilepsy (p=0.03). On postnatal imaging, open defects often involuted (8/11) and there were high rates of new/additional findings (4/6).

Conclusions: In this cohort, fetal schizencephaly was always associated with additional intracranial abnormalities. In most cases, there was evidence that schizencephaly was likely secondary to prior injury. Imaging characteristics may provide clues regarding neurodevelopmental outcome. Postnatal imaging is crucial in assessing evolution as well as for detection of additional abnormalities.

Abbreviations: ICH = intracranial hemorrhage; CM = cortical malformation; VM = ventriculomegaly; DGN = deep grey nuclei; SP = septum pellucidum; IPH = intraparenchymal hemorrhage; CC = corpus callosum; PMG = polymicrogyria; PVNH = periventricular nodular heterotopia; TTTS = twin-twin transfusion syndrome; GA = gestational age; CP = cerebral palsy.

Background and purpose: Complications from endovascular thrombectomy (EVT) can negatively affect clinical outcomes, making the development of a more precise and objective prediction model essential. This research aimed to assess the effectiveness of radiomic features derived from pre-surgical CT scans in predicting the prognosis post- EVT in acute ischemic stroke patients.

Materials and methods: This investigation included 336 acute ischemic stroke patients from two medical centers, spanning from March 2018 to March 2024. The participants were split into a training cohort of 161 patients and a validation cohort of 175 patients. Patient outcomes were rated with the mRS: 0-2 for good, 3-6 for poor. A total of 428 radiomic features were derived from intra-thrombus and peri-thrombus regions in non-contrast CT and CT angiography images. Feature selection was conducted using a least absolute shrinkage and selection operator regression model. The efficacy of eight different supervised learning models was assessed using the area under the curve (AUC) of the receiver operating characteristic curve.

Results: Among all models tested in the validation cohort, the logistic regression algorithm for combined model achieved the highest AUC (0.87, with a 95% confidence interval of 0.81 to 0.92), outperforming other algorithms. The combined use of radiomic features from both the intra-thrombus and peri-thrombus regions significantly enhanced diagnostic accuracy over models using features from a single region (0.81 vs 0.70, 0.77), highlighting the benefit of integrating data from both regions for improved prediction.

Conclusions: The findings suggest that a combined radiomics model based on CT imaging serves as a potent approach to assessing the prognosis following EVT. The logistic regression model, in particular, proved to be both effective and stable, offering critical insights for the management of stroke.

Abbreviations: AUC=area under the curve; EVT=endovascular thrombectomy; KNN=k-nearest neighbors; LASSO=least absolute shrinkage and selection operator; LightGBM=Light Gradient Boosting Machine; LR=logistic regression; MLP=multi-layer perceptron; RF=random forest; SVM=support vector machine; XGBoost=extreme gradient boosting.

Background and purpose: Hemorrhagic transformation remains a potentially devastating complication of acute ischemic stroke. We aimed to evaluate whether the hypoperfusion intensity ratio, a parameter derived from CT perfusion imaging, is associated with the development of hemorrhagic transformation in patients with anterior large-artery occlusion who had undergone thrombectomy.

Materials and methods: We retrospectively reviewed data from patients with consecutive acute ischemic strokes who had achieved successful recanalization (Thrombolysis in Cerebral Infarction score ≥2b) between January 2020 and December 2023. HIR was defined as the ratio of the volume of lesions with a time-to-maximum (Tmax) >6 seconds to those with a Tmax >10 second delay. The primary outcome, based on the European Cooperative Acute Stroke Study, was hemorrhagic transformation, diagnosed by follow-up imaging assessment in 24-hour windows, and radiologically classified as hemorrhagic infarction and parenchymal hematoma. The secondary outcome was a 3-month mRS score of ≥3.

Results: Among 168 patients, 35 of 168 developed hemorrhagic transformation; 14 of 168 developed hemorrhagic infarction, and 21 of 168 developed parenchymal hematoma PH. After adjusting the latent covariates, increased hypoperfusion intensity ratio (per 0.1, adjusted OR [aOR] 1.68, 95% CI 1.26-2.25), ASPECTS (aOR 0.44, 95% CI 0.27-0.72), onset-to-puncture (aOR 1.01, 95% CI 1.00-1.02), and cardioembolism (aOR 5.6, 95% CI 1.59-19.7) were associated with hemorrhagic transformation in multivariable regression. The receiver operating characteristic curve indicated that hypoperfusion intensity ratio can predict hemorrhagic transformation accurately (area under the curve = 0.81; 95% CI, 0.738-0.882; P < .001) and predict parenchymal hematoma (area under the curve = 0.801; 95% CI, 0.727-0.875; P < .001).

Conclusions: Upon admission, hypoperfusion intensity ratio, an imaging parameter, predicted hemorrhagic transformation after reperfusion therapy in this patient population.

Background and purpose: Various imaging techniques have been described to detect CSF-venous fistulas in the setting of spontaneous intracranial hypotension, including decubitus CT myelography. The expected diagnostic yield of decubitus CT myelography for CSF-venous fistula detection is not fully established. The purpose of this study was to assess the yield of decubitus CT myelography among consecutive patients presenting for evaluation of possible spontaneous intracranial hypotension and to examine the impact of brain MR imaging findings of spontaneous intracranial hypotension on the diagnostic yield.

Materials and methods: The study included a single-center, retrospective cohort of consecutive patients presenting during a 1-year period who underwent CT myelography and had no CSF identified in the epidural space. Patients with epidural CSF leaks were included in a secondary cohort. Subjects were grouped according to positioning for the myelogram, either decubitus or prone, and the presence of imaging findings of spontaneous intracranial hypotension on preprocedural brain MR imaging. Diagnostic yields for each subgroup were calculated, and the yield of decubitus CT myelography was compared with that of prone CT myelography.

Results: The study cohort comprised 302 subjects, including 247 patients with no epidural fluid. The diagnostic yield of decubitus CT myelography for CSF-venous fistula detection among subjects with positive brain MR imaging findings and no epidural fluid was 73%. No CSF-venous fistulas were identified among subjects with negative findings on brain imaging. Among subjects with an epidural leak, brain MR imaging was negative for signs of spontaneous intracranial hypotension in 22%. Prone CT myelography identified a CSF-venous fistula less commonly than decubitus CT myelography (43% versus 73%, P = .19), though the difference was not statistically significant in this small subgroup.

Conclusions: We found the diagnostic yield of decubitus CT myelography to be similar to the yield previously reported for digital subtraction myelography among patients with positive findings on brain imaging. No CSF-venous fistulas were identified in patients with negative findings on brain imaging; epidural CSF leaks accounted for all cases of patients who had spontaneous intracranial hypotension with negative brain imaging findings. This study provides useful data for counseling patients and helps establish a general benchmark for the decubitus CT myelography yield for CSF-venous fistula detection.