Abnormal Thalamo-Cortical Interactions in Overlapping Communities of Migraine: An Edge Functional Connectivity Study.

OBJECTIVE: Migraine has been demonstrated to exhibit abnormal functional connectivity of large-scale brain networks, which is closely associated with its pathophysiology and has not yet been explored by edge functional connectivity. We used an edge-centric approach combined with motif analysis to evaluate higher-order communication patterns of brain networks in migraine. METHODS: We investigated edge-centric metrics in 108 interictal migraine patients and 71 healthy controls. We parcellated the brain into networks using independent component analysis. We applied edge graph construction, k-means clustering, community overlap detection, graph-theory-based evaluations, and clinical correlation analysis. We conducted motif analysis to explore the interactions among regions, and a classification model to test the specificity of edge-centric results. RESULTS: The normalized entropy of lateral thalamus was significantly increased in migraine, which was positively correlated with the baseline headache duration, and negatively correlated with headache duration reduction following preventive medications at 3-month follow-up. Network-wise entropy of the sensorimotor network was significantly elevated in migraine. The community similarity between lateral thalamus and postcentral gyrus was enhanced in migraine. Migraine patients showed overrepresented L-shape and diverse motifs, and underrepresented forked motifs with lateral thalamus serving as the reference node. Furthermore, migraine patients presented with overrepresented L-shape triads, where the postcentral gyrus shared different edges with the lateral thalamus. The classification model showed that entropy of the lateral thalamus had the highest discriminative power, with an area under the curve of 0.86. INTERPRETATION: Our findings indicated an abnormal higher-order thalamo-cortical communication pattern in migraine patients. The thalamo-cortical-somatosensory disturbance of concerted working may potentially lead to aberrant information flow and deficit pain processing of migraine. ANN NEUROL 2023;94:1168-1181.

Synthesized 7T MPRAGE From 3T MPRAGE Using Generative Adversarial Network and Validation in Clinical Brain Imaging: A Feasibility Study.

BACKGROUND: Ultra-high field 7T MRI can provide excellent tissue contrast and anatomical details, but is often cost prohibitive, and is not widely accessible in clinical practice. PURPOSE: To generate synthetic 7T images from widely acquired 3T images with deep learning and to evaluate the feasibility of this approach for brain imaging. STUDY TYPE: Prospective. POPULATION: 33 healthy volunteers and 89 patients with brain diseases, divided into training, and evaluation datasets in the ratio 4:1. SEQUENCE AND FIELD STRENGTH: T1-weighted nonenhanced or contrast-enhanced magnetization-prepared rapid acquisition gradient-echo sequence at both 3T and 7T. ASSESSMENT: A generative adversarial network (SynGAN) was developed to produce synthetic 7T images from 3T images as input. SynGAN training and evaluation were performed separately for nonenhanced and contrast-enhanced paired acquisitions. Qualitative image quality of acquired 3T and 7T images and of synthesized 7T images was evaluated by three radiologists in terms of overall image quality, artifacts, sharpness, contrast, and visualization of vessel using 5-point Likert scales. STATISTICAL TESTS: Wilcoxon signed rank tests to compare synthetic 7T images with acquired 7T and 3T images and intraclass correlation coefficients to evaluate interobserver variability. P < 0.05 was considered significant. RESULTS: Of the 122 paired 3T and 7T MRI scans, 66 were acquired without contrast agent and 56 with contrast agent. The average time to generate synthetic images was ~11.4 msec per slice (2.95 sec per participant). The synthetic 7T images achieved significantly improved tissue contrast and sharpness in comparison to 3T images in both nonenhanced and contrast-enhanced subgroups. Meanwhile, there was no significant difference between acquired 7T and synthetic 7T images in terms of all the evaluation criteria for both nonenhanced and contrast-enhanced subgroups (P ≥ 0.180). DATA CONCLUSION: The deep learning model has potential to generate synthetic 7T images with similar image quality to acquired 7T images. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

Alteration of White Matter Connectivity for MR-Guided Focused Ultrasound in the Treatment of Essential Tremor.

BACKGROUND: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy has been implemented as a therapeutic alternative for the treatment of drug-refractory essential tremor (ET). However, its impact on the brain structural network is still unclear. PURPOSE: To investigate both global and local alterations of the white matter (WM) connectivity network in ET after MRgFUS thalamotomy. STUDY TYPE: Retrospective. SUBJECTS: Twenty-seven ET patients (61 ± 11 years, 19 males) with MRgFUS thalamotomy and 28 healthy controls (HC) (61 ± 11 years, 20 males) were recruited for comparison. FIELD STRENGTH/SEQUENCE: A 3 T/single shell diffusion tensor imaging by using spin-echo-based echo-planar imaging, three-dimensional T1 weighted imaging by using gradient-echo-based sequence. ASSESSMENT: Patients were undergoing MRgFUS thalamotomy and their clinical data were collected from pre-operation to 6-month post-operation. Network topological metrics, including rich-club organization, small-world, and efficiency properties were calculated. Correlation between the topological metrics and tremor scores in ET groups was also calculated to assess the role of neural remodeling in the brain. STATISTICAL TESTS: Two-sample independent t-tests, chi-squared test, ANOVA, Bonferroni test, and Spearman's correlation. Statistical significance was set at P < 0.05. RESULTS: For ET patients, the strength of rich-club connection and clustering coefficient significantly increased vs. characteristic path length decreased at 6-month post-operation compared with pre-operation. The distribution pattern of rich-club regions was different in ET groups. Specifically, the order of the rich-club regions was changed according to the network degree value after MRgFUS thalamotomy. Moreover, the altered nodal efficiency in the right temporal pole of the superior temporal gyrus (R = 0.434-0.596) and right putamen (R = 0.413-0.436) was positively correlated with different tremor improvement. DATA CONCLUSION: These findings might improve understanding of treatment-induced modulation from a network perspective and may work as an objective marker in the assessment of ET tremor control with MRgFUS thalamotomy. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 4.

MRI Assessment of Brain Frailty and Clinical Outcome in Patients With Acute Posterior Perforating Artery Infarction.

BACKGROUND: Global brain health has gained increasing attention recently. Imaging markers of brain frailty have been related to functional outcomes in previous studies on anterior circulation; however, little data are available on imaging markers and posterior circulation. PURPOSE: To investigate the impact of brain frailty on functional outcomes in patients with acute perforating artery infarction (PAI) of the posterior circulation. STUDY TYPE: Prospective. POPULATION: One hundred patients (60.78 ± 9.51 years, 72% men) with acute posterior circulation PAI (determined by diffusion-weighted magnetic resonance imaging (MRI)/time-of-flight MR angiography). FIELD STRENGTH/SEQUENCE: T1- and T2-weighted fast spin echo, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted echo planar, gradient echo (susceptibility-weight imaging), and 3D time-of-flight MR angiography sequences at 3.0 T. ASSESSMENT: Periventricular and deep white matter hyperintensities (WMH), enlarged perivascular spaces (EPVS) in the basal ganglia and centrum semiovale area, lacunes, cerebral microbleeds (CMB), and total brain frailty score by calculating the above imaging characters were rated visually by three radiologists with 9, 10, and 11 years of experience and one neuroradiologist with 12. Infarction volume was assessed using baseline diffusion-weighted imaging (DWI) data obtained within 24 hours of symptom onset. A modified Rankin Scale (mRS) score >1 on day 90 defined an adverse functional outcome. Associations between the imaging markers of brain frailty and functional outcomes were assessed. STATISTICAL TESTS: Fisher's exact test, Mann-Whitney U test, and multivariable binary logistic regression. A P value <0.05 was considered statistically significant. RESULTS: Adverse prognoses (mRS > 1) were observed in 34 (34%) patients. Infarction volume, periventricular WMH, deep WMH, basal ganglia EPVS, CMB, and the brain frailty score were significantly associated with adverse functional outcomes. An increased brain frailty score was significantly associated with unfavorable mRS score on day 90 (odds ratio 1.773, 95% confidence interval 1.237-2.541). DATA CONCLUSION: Advanced MRI imaging markers of brain frailty, individually or combined as a total brain frailty score, were associated with worse functional outcomes after acute posterior circulation PAI. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 3.

Deep medullary vein damage correlates with small vessel disease in small vessel occlusion acute ischemic stroke.

OBJECTIVES: We aim to investigate whether cerebral small vessel disease (cSVD) imaging markers correlate with deep medullary vein (DMV) damage in small vessel occlusion acute ischemic stroke (SVO-AIS) patients. METHODS: The DMV was divided into six segments according to the regional anatomy. The total DMV score (0-18) was calculated based on segmental continuity and visibility. The damage of DMV was grouped according to the quartiles of the total DMV score. Neuroimaging biomarkers of cSVD including white matter hyperintensity (WMH), cerebral microbleed (CMB), perivascular space (PVS), and lacune were identified. The cSVD score were further analyzed. RESULTS: We included 229 SVO-AIS patients, the mean age was 63.7 ± 23.1 years, the median NIHSS score was 3 (IQR, 2-6). In the severe DMV burden group (the 4th quartile), the NIHSS score grade (6 (3-9)) was significantly higher than other groups (p < 0.01). The grade scores for basal ganglia PVS (BG-PVS) were positively correlated with the degree of DMV (R = 0.67, p < 0.01), rather than centrum semivole PVS (CS-PVS) (R = 0.17, p = 0.1). In multivariate analysis, high CMB burden (adjusted odds ratio [aOR], 25.38; 95% confidence interval [CI], 1.87-345.23) was associated with severe DMV scores. In addition, BG-PVS was related to severe DMV burden in a dose-dependent manner: when BG-PVS score was 3 and 4, the aORs of severe DMV burden were 18.5 and 12.19, respectively. CONCLUSION: The DMV impairment was associated with the severity of cSVD, which suggests that DMV burden may be used for risk stratification in SVO-AIS patients. CLINICAL RELEVANCE STATEMENT: The DMV damage score, based on the association between small vessel disease and the deep medullary veins impairment, is a potential new imaging biomarker for the prognosis of small vessel occlusion acute ischemic stroke, with clinical management implications. KEY POINTS: • The damage to the deep medullary vein may be one mechanism of cerebral small vessel disease. • Severe burden of the basal ganglia perivascular space and cerebral microbleed is closely associated with significant impairment to the deep medullary vein. • The deep medullary vein damage score may reflect a risk of added vascular damage in small vessel occlusion acute ischemic stroke patients.

Generative Adversarial Network-based Noncontrast CT Angiography for Aorta and Carotid Arteries.

Background Iodinated contrast agents (ICAs), which are widely used in CT angiography (CTA), may cause adverse effects in humans, and their use is time-consuming and costly. Purpose To develop an ICA-free deep learning imaging model for synthesizing CTA-like images and to assess quantitative and qualitative image quality as well as the diagnostic accuracy of synthetic CTA (Syn-CTA) images. Materials and Methods A generative adversarial network (GAN)-based CTA imaging model was trained, validated, and tested on retrospectively collected pairs of noncontrast CT and CTA images of the neck and abdomen from January 2017 to June 2022, and further validated on an external data set. Syn-CTA image quality was evaluated using quantitative metrics. In addition, two senior radiologists scored the visual quality on a three-point scale (3 = good) and determined the vascular diagnosis. The validity of Syn-CTA images was evaluated by comparing the visual quality scores and diagnostic accuracy of aortic and carotid artery disease between Syn-CTA and real CTA scans. Results CT scans from 1749 patients (median age, 60 years [IQR, 50-68 years]; 1057 male patients) were included in the internal data set: 1137 for training, 400 for validation, and 212 for testing. The external validation set comprised CT scans from 42 patients (median age, 67 years [IQR, 59-74 years]; 37 male patients). Syn-CTA images had high similarity to real CTA images (normalized mean absolute error, 0.011 and 0.013 for internal and external test set, respectively; peak signal-to-noise ratio, 32.07 dB and 31.58 dB; structural similarity, 0.919 and 0.906). The visual quality of Syn-CTA and real CTA images was comparable (internal test set, P = .35; external validation set, P > .99). Syn-CTA showed reasonable to good diagnostic accuracy for vascular diseases (internal test set: accuracy = 94%, macro F1 score = 91%; external validation set: accuracy = 86%, macro F1 score = 83%). Conclusion A GAN-based model that synthesizes neck and abdominal CTA-like images without the use of ICAs shows promise in vascular diagnosis compared with real CTA images. Clinical trial registration no. NCT05471869 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Zhang and Turkbey in this issue.

Apparent Diffusion Coefficient as Imaging Biomarker for Identifying IDH Mutation, 1p19q Codeletion, and MGMT Promoter Methylation Status in Patients With Glioma.

BACKGROUND: Glioma genotypes are of importance for clinical decision-making. This data can only be acquired through histopathological analysis based on resection or biopsy. Consequently, there is a need for alternative biomarkers that noninvasively provide reliable information for preoperatively identifying molecular characteristics. PURPOSE: To investigate apparent diffusion coefficient (ADC) as imaging biomarker for preoperatively identifying glioma genotypes based on the 2021 World Health Organization (WHO) classification of central nervous system (CNS) tumors. STUDY TYPE: Retrospective. SUBJECTS: One hundred and fifty-nine patients (47.6 ± 14.4 years) diagnosed with WHO grade 2-4 glioma including 93 males and 66 females. FIELD STRENGTH/SEQUENCE: A 3 T/spin echo echo planner imaging. ASSESSMENT: The ADC measurements were assessed by two neuroradiologists (both with 6 years of experience). Three different lowest portions inside the tumors without overlap were manually drawn on the ADC maps as regions of interest (ROIs). The mean ADC value of the three ROIs was defined as the minimum ADC value (ADCmin ). An ROI was placed in the contralateral normal appearing white matter (NAWM) to obtain the ADC value (ADCNAWM ). The ADCmin to ADCNAWM ratio (ADCratio ) was calculated. Genetics results were retrospectively recorded from pathologic and genetic test reports. STATISTICAL TESTS: Two-sample independent t-tests, receiver operating characteristic curve analysis, and intraclass correlation coefficient analysis were used. Statistical significance was set at P < 0.05. RESULTS: Isocitrate dehydrogenase (IDH)-mutated glioma showed higher ADCmin and ADCratio than IDH wild-type glioma. Among IDH-mutated glioma, higher ADCmin and ADCratio were found in 1p19q intact glioma than in 1p19q codeletion glioma. ADC parameters enabled differentiation of IDH mutation status with area under the curve (AUC) of 0.84 and 0.86. DATA CONCLUSION: ADC has potential discriminative value for IDH mutation and 1p19q codeletion status. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 2.

Arterial Spin Labeling-Based MRI Estimation of Penumbral Tissue in Acute Ischemic Stroke.

BACKGROUND: Arterial spin labeling (ASL) has shown potential for the assessment of penumbral tissue in patients with acute ischemic stroke (AIS). The postlabeling delay (PLD) parameter is sensitive to arterial transit delays and influences cerebral blood flow measurements. PURPOSE: To assess the impact of ASL acquisition at different PLDs for penumbral tissue quantification and to compare their performance regarding assisting patient selection for endovascular treatment with dynamic susceptibility contrast MRI (DSC-MRI) as the reference method. STUDY TYPE: Retrospective. POPULATION: A total of 53 patients (59.98 ± 12.60 years, 32% women) with AIS caused by internal carotid or middle cerebral artery occlusion. FIELD STRENGTH/SEQUENCE: A 3-T, three-dimensional pseudo-continuous ASL with fast-spin echo readout. ASSESSMENT: Hypoperfusion volume was measured using DSC-MRI and ASL with PLDs of 1.500 msec and 2.500 msec, respectively. Eligibility for endovascular treatment was retrospectively determined according to the imaging criteria of the Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke trial (DEFUSE 3). STATISTICAL TESTS: Kruskal-Wallis tests, Bland-Altman plots, Cohen's kappa, and receiver operating characteristic analyses were used. The threshold for statistical significance was set at P Ë‚ 0.05. RESULTS: Hypoperfusion volume for ASL with a PLD of 1.500 msec was significantly larger than that for DSC-MRI, while the hypoperfusion volume for a PLD of 2.500 msec was not significantly different from that of DSC-MRI (P = 0.435). Bland-Altman plots showed that the mean volumetric error between the hypoperfusion volume measured by DSC-MRI and ASL with PLDs of 1.500/2.500 msec was -107.0 mL vs. 4.49 mL. Cohen's kappa was 0.679 vs. 0.773 for DSC-MRI and ASL, respectively, with a PLD of 1.500/2.500 msec. The sensitivity and specificity for ASL with a PLD of 1.500/2.500 msec in identifying patients eligible for treatment were 89.74% vs. 97.44% and 92.86% vs. 64.29%, respectively. DATA CONCLUSION: In AIS, PLDs for ASL acquisition may have a considerable impact on the quantification of the hypoperfusion volume. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Accelerating susceptibility-weighted imaging with deep learning by complex-valued convolutional neural network (ComplexNet): validation in clinical brain imaging.

OBJECTIVES: Susceptibility-weighted imaging (SWI) is crucial for the characterization of intracranial hemorrhage and mineralization, but has the drawback of long acquisition times. We aimed to propose a deep learning model to accelerate SWI, and evaluate the clinical feasibility of this approach. METHODS: A complex-valued convolutional neural network (ComplexNet) was developed to reconstruct high-quality SWI from highly accelerated k-space data. ComplexNet can leverage the inherently complex-valued nature of SWI data and learn richer representations by using complex-valued network. SWI data were acquired from 117 participants who underwent clinical brain MRI examination between 2019 and 2021, including patients with tumor, stroke, hemorrhage, traumatic brain injury, etc. Reconstruction quality was evaluated using quantitative image metrics and image quality scores, including overall image quality, signal-to-noise ratio, sharpness, and artifacts. RESULTS: The average reconstruction time of ComplexNet was 19 ms per section (1.33 s per participant). ComplexNet achieved significantly improved quantitative image metrics compared to a conventional compressed sensing method and a real-valued network with acceleration rates of 5 and 8 (p < 0.001). Meanwhile, there was no significant difference between fully sampled and ComplexNet approaches in terms of overall image quality and artifacts (p > 0.05) at both acceleration rates. Furthermore, ComplexNet showed comparable diagnostic performance to the fully sampled SWI for visualizing a wide range of pathology, including hemorrhage, cerebral microbleeds, and brain tumor. CONCLUSIONS: ComplexNet can effectively accelerate SWI while providing superior performance in terms of overall image quality and visualization of pathology for routine clinical brain imaging. KEY POINTS: • The complex-valued convolutional neural network (ComplexNet) allowed fast and high-quality reconstruction of highly accelerated SWI data, with an average reconstruction time of 19 ms per section. • ComplexNet achieved significantly improved quantitative image metrics compared to a conventional compressed sensing method and a real-valued network with acceleration rates of 5 and 8 (p < 0.001). • ComplexNet showed comparable diagnostic performance to the fully sampled SWI for visualizing a wide range of pathology, including hemorrhage, cerebral microbleeds, and brain tumor.

FLAIR vessel hyperintensities predict functional outcomes in patients with acute ischemic stroke treated with medical therapy.

OBJECTIVES: The prognostic value of fluid-attenuated inversion recovery vessel hyperintensity (FVH) remains controversial in acute ischemic stroke (AIS). The objective was to investigate whether the presence of FVH could predict long-term functional outcomes in patients with AIS receiving medical therapy. METHODS: Consecutive AIS patients with anterior circulation large vessel stenosis (LVS) in multiple centers between January 2019 and December 2020 were studied. Presence of FVH was identified and evaluated as FVH (+). Quantification of FVH was performed using an FVH-Alberta Stroke Program Early CT Score (ASPECTS) system and divided into grades: FVH-ASPECTS of 0 = grade 0; 1-2 = grade 1; 3-7 = grade 2. Poor functional outcome was defined as modified Rankin scale > 2 at 3 months. RESULTS: Overall, 175 patients were analyzed (age, 64.31 ± 13.47 years; men, 65.1%), and 78.9% patients presented with FVH. Larger infarct volume (19.90 mL vs. 5.50 mL, p < 0.001), higher rates of FVH (+) (92.0% vs. 65.9%, p < 0.001), and higher FVH grades (grade 2, 34.5% vs. 10.2%, p < 0.001) were more prone to be observed in patients with poor functional outcomes. FVH (+) with infarct volume larger than 6.265 mL (adjusted odds ratio [aOR] 6.03, 95% confidence interval [CI] 1.82-19.98) and FVH grade (grade 1, aOR 3.07, 95% CI 1.12-8.43; grade 2, aOR 5.80, 95% CI 1.59-21.11) were independently associated with poor functional outcomes. CONCLUSION: FVH (+) combined with large infarct volume and high FVH grade can predict poor long-term functional outcomes in patients with LVS who receive medical therapy. KEY POINTS: • FVH is expected to be a contrast agent-independent alternative for assessing hemodynamic status in the acute stage of stroke. • FVH (+) and high FVH grade, quantified by FVH-ASPECTS rating system and grades, are associated with large infarct volume. • The combination of FVH and DWI-based infarct volume has independent predictive value for long-term functional outcomes in AIS patients with large artery stenosis treated with medical therapy.

Assessing the impact of MR-guided focused ultrasound thalamotomy on brain activity and connectivity in patients with essential tremor.

OBJECTIVE: Although magnetic resonance-guided focused ultrasound (MRgFUS) at the ventral intermediate (VIM) thalamic nucleus is a novel and effective treatment for medication-refractory essential tremor (ET), it is unclear how the ablation lesion affects functional activity. The current study sought to evaluate the functional impact of MRgFUS thalamotomy in patients with ET, as well as to investigate the relationship between neuronal activity changes and tremor control. METHODS: This study included 30 patients with ET who underwent MRgFUS thalamotomy with a 6-month follow-up involving MRI and clinical tremor rating. Additional sex- and age-matched healthy people were recruited for the healthy control group. The fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity were used to identify functional alteration regions of interest (ROIs). To investigate changes after treatment, ROI- and seed-based functional connectivity (FC) analyses were performed. RESULTS: Patients with ET had significantly increased fALFF in the right postcentral gyrus (PoCG; ROI 1), regional homogeneity in the left PoCG (ROI 2), and regional homogeneity in the right PoCG (ROI 3, cluster-level p value family-wise error [pFWE] < 0.05), which were recovered and normalized at 6 months after MRgFUS thalamotomy. FCs between ROI 2 and the right supramarginal gyrus, ROI 2 and the right superior parietal gyrus, and ROI 3 and the left precentral gyrus were also found to be increased after treatment (cluster-level pFWE < 0.05). Furthermore, changes in fALFF, regional homogeneity, and FC values were significantly correlated with tremor relief (p < 0.05). Preoperative FC strengths were found to be inversely related to the postoperative tremor control ratio (p < 0.05). CONCLUSIONS: In patients with ET, the VIM lesion of MRgFUS thalamotomy resulted in symptom-related regional functional recovery associated with sensorimotor and attention networks. Preoperative FC strengths may reflect the postoperative tremor control ratio, implying that this metric could be a useful neuroimaging biomarker for predicting symptom relief in patients with ET following thalamotomy.

Highly Sensitive Homogeneous Electrochemiluminescence Biosensor for Alkaline Phosphatase Detection Based on Click Chemistry-Triggered Branched Hybridization Chain Reaction.

Alkaline phosphatase (ALP) has been used as a diagnostic index of clinical diseases since its expression level is closely related to many pathological processes. In this work, a highly sensitive electrochemiluminescence (ECL) method for the determination of ALP based on a click chemistry-induced branched hybridization chain reaction (BHCR) for signal amplification and ultrafiltration technology for the separation of homogeneous amplification products is introduced. ALP can release copper ions from a Cu2+/PPi complex by hydrolyzing pyrophosphoric acid, which initiates click chemistry in the system. A BHCR amplification is triggered afterward by the long single-stranded DNA (ssDNA) generated by click chemistry, resulting in a three-dimensional double-stranded DNA (dsDNA) with a large molecular weight. Based on the characteristic that Ru(phen)32+ can stably insert into the groove of dsDNA, a large amount of Ru(phen)32+ is retained together with the amplified product after ultrafiltration, and therefore a significantly enhanced ECL signal can be obtained. The test results show that this method can be used for the quantitative determination of ALP ranging from 0.002 to 50 U/L, with a detection limit of 0.7 mU/L. This method has also been confirmed to have good selectivity and anti-interference, and the results of the analysis of the ALP content in the diluted serum samples are satisfactory, showing great application potential in clinical diagnosis.

[Quality Control Test of Transcranial MRI-guided Focused Ultrasound Treatment System before Surgery].

OBJECTIVE: To investigate the pre-treatment preventive maintenance and quality control procedure of MRI system and transcranial MRI-guided focused ultrasound (TcMRgFUS) treatment system by monitoring quality control of these two systems. METHODS: The general performance index and image quality control index of MRI system, as well as the quality assurance program of TcMRgFUS EXABLATE 4000 system were tested and recorded. RESULTS: The general performance index and image quality control index of MRI system met requirements. CONCLUSIONS: Through system detection, the system performance could be monitored, ensuring the accuracy and safety of surgery.

Proposed modified diagnostic criteria for recurrent painful ophthalmoplegic neuropathy: Five case reports and literature review.

BACKGROUND: Recurrent painful ophthalmoplegic neuropathy (RPON) is an uncommon disorder characterized by recurrent unilateral headache attacks associated with ipsilateral ophthalmoplegia. We intend to study the clinical picture in our case series along with the published literature to discuss the pathogenesis and propose modified diagnostic criteria for recurrent painful ophthalmoplegic neuropathy. METHODS: We reported five cases diagnosed as ophthalmoplegic migraine/RPON in our medical centers and reviewed the published literature related to RPON from the Pubmed database between 2000 and 2020. In one of these cases, a multiplanar reformation was performed to look at the aberrant cranial nerve. RESULTS: The mean onset age for RPON was 22.1 years, and the oculomotor nerve was the most commonly involved cranial nerve (53.9%) in 165 reviewed patients. In most patients, ophthalmoplegia started within 1 week of the headache attack (95.7%, 67/70). Additionally, 27.6% (40/145) of patients presented enhancement of the involved nerve(s) from MRI tests. Finally, 78 patients received corticosteroids, out of which 96.2% benefited from them. CONCLUSION: This is the first time multiplanar reformation has been performed to reveal the distortion of the oculomotor nerve. Modified diagnostic criteria are proposed. We hope to expand the current knowledge and increase the detection of recurrent painful ophthalmoplegic neuropathy in the future.

Cardiac cephalalgia: one case with cortical hypoperfusion in headaches and literature review.

BACKGROUND: Cardiac cephalalgia (CC) is a rare disease occurring during an episode of myocardial ischemia and relieved by nitroglycerine. Though more than 30 cases of CC have been reported since 1997, the mechanism is yet obscure. Herein, a case of CC is presented and discussed in relevance with previous literature to propose a novel hypothesis about the mechanism of CC. METHOD: A CC patient with cortical hypoperfusion during headache attacks was presented, which has never been reported. All published cases of CC via PubMed ( http://www.ncbi.nlm.nih.gov/pubmed ) in English literature, between 1997 and 2016, were reviewed. RESULTS: A patient suffering from CC presented a cerebral hypoperfusion during a headache attack. This phenomenon had not been observed since CC was introduced in 1997. The literature review summarized the clinical presentations, neuroimaging features, ECG, and coronary angiography features of 35 CC patients. CONCLUSION: Based on the phenomenon of hypoperfusion in the event of a headache, the vessel constriction hypothesis was proposed including two potential physiological mechanisms underlying the pathophysiology of CC.

MRI evaluation of lateral geniculate body in normal aging brain using quantitative susceptibility mapping.

OBJECTIVE: To investigate the changes of lateral geniculate body (LGB) in the normal aging brain using quantitative susceptibility mapping (QSM) technique. METHODS: Magnetic resonance (MR) phase and magnitude images were acquired from enhanced gradient echo T2 star weighted angiography sequence with 16 echoes on 3.0T MR system using the head coil with 32 channels. Morphology Enabled Dipole Inversion (MEDI) method was applied for QSM, and the susceptibility value of LGB was measured by region of interest (ROI) drawn manually on three orthogonal planes. RESULTS: LGB of the middle-aged group had a higher susceptibility value (0.16±0.05 ppm) than that of the youth group (0.12±0.05 ppm) and elderly group (0.13±0.03 ppm) (all P<0.05). Partial correlation analysis demonstrated that there was significantly positive correlation between susceptibility value and age in the youth group (r=0.71, P<0.05). CONCLUSION: LGB could clearly be identified on QSM in the brain in vivo.

Predicting tremor improvement after MRgFUS thalamotomy in essential tremor from preoperative spontaneous brain activity: A machine learning approach.

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) thalamotomy is an emerging technique for medication-refractory essential tremor (ET), but with variable outcomes. This study used pattern regression analysis to identify brain signatures predictive of tremor improvements. Fifty-four ET patients (mean age = 63.06 years, standard deviation (SD) = 10.55 years, 38 males) underwent unilateral MRgFUS thalamotomy and were scanned for resting-state functional magnetic resonance imaging (rs-fMRI). Seventy-four healthy controls (mean age = 58.09 years, SD = 10.30 years, 38 males) were recruited for comparison. Tremor responses at 12 months posttreatment were evaluated by the Clinical Rating Scale for Tremor. The fractional amplitude of low-frequency fluctuations (fALFF) was calculated from rs-fMRI data. Two-sample t-test was used to generate a disease-specific mask, within which Multivariate Kernel Ridge Regression analyses were conducted. Predicted and actual clinical scores were compared using Pearson's correlation coefficient (r) and normalized mean squared error (Norm. MSE). Permutation test and leave-one-out strategy were applied for results validation. KRR identified fALFF patterns that significantly predicted the hand tremor improvement (r = 0.23, P = 0.025; Norm. MSE = 0.05, P = 0.026) and the postural tremor improvement (r = 0.28, P = 0.025; Norm. MSE = 0.06, P = 0.023), but not action tremor improvement. Lobule VI of right cerebellum (Cerebelum_6_R), right superior occipital gyrus (Occipital_Sup_R) and lobule X of vermis (Vermis_10) contributed most for hand tremor prediction (normalized weights (NW): 2.77%, 2.40%, 2.34%) while Vermis_10, left supplementary motor area (Supp_Motor_Area_L) and right hippocampus (Hippocampus_R) for postural tremor prediction (NW: 2.69%, 2.12%, 2.05%). The low contributing NW of the individual brain regions suggested that the fALFF pattern as a whole is an overall predicting feature. Preoperative fALFF pattern predicts tremor benefits induced by MRgFUS thalamotomy. ClinicalTrials.gov number: NCT04570046.

Imaging Assessments and Clinical Significance of Brain Frailty in Moyamoya Disease.

BACKGROUND AND PURPOSE: Imaging assessment of brain frailty in ischemic stroke has been extensively studied, while the correlation between brain frailty and Moyamoya disease remains obscure. This study aimed to investigate the imaging characteristics of brain frailty and its clinical applications in Moyamoya disease. MATERIALS AND METHODS: This study included 60 patients with Moyamoya disease (107 hemispheres). All patients were divided into stroke and nonstroke groups based on clinical symptoms and imaging findings. The modified brain frailty score was adapted to consider 4 imaging signs: white matter hyperintensity, enlargement of perivascular space, old vascular lesions, and cerebral microbleed. The relative CBF of the MCA territory was quantified using pseudocontinuous arterial-spin labeling. Surgical outcome after revascularization surgery was defined by the Matsushima grade. RESULTS: The relative CBF of the MCA territory decreased as the modified brain frailty score and periventricular white matter hyperintensity grades increased (ρ = -0.22, P = .02; ρ = -0.27, P = .005). Clinically, the modified brain frailty score could identify patients with Moyamoya disease with stroke (OR = 2.00, P = .02). Although the modified brain frailty score showed no predictive value for surgical outcome, basal ganglia enlargement of the perivascular space had a significant correlation with the postoperative Matsushima grade (OR = 1.29, P = .03). CONCLUSIONS: The modified brain frailty score could reflect a cerebral perfusion deficit and clinical symptoms of Moyamoya disease, and its component basal ganglia enlargement of perivascular space may be a promising marker to predict surgical outcome and thus aid future clinical decision-making.

Magnetic resonance-guided focused ultrasound for essential tremor: a prospective, single center, single-arm study.

JOURNAL/nrgr/04.03/01300535-202409000-00041/figure1/v/2024-01-16T170235Z/r/image-tiff The safety and effectiveness of magnetic resonance-guided focused ultrasound thalamotomy has been broadly established and validated for the treatment of essential tremor. In 2018, the first magnetic resonance-guided focused ultrasound system in Chinese mainland was installed at the First Medical Center of the PLA General Hospital. This prospective, single center, open-label, single-arm study was part of a worldwide prospective multicenter clinical trial (ClinicalTrials.gov Identifier: NCT03253991) conducted to confirm the safety and efficacy of magnetic resonance-guided focused ultrasound for treating essential tremor in the local population. From 2019 to 2020, 10 patients with medication refractory essential tremor were recruited into this open-label, single arm study. The treatment efficacy was determined using the Clinical Rating Scale for Tremor. Safety was evaluated according to the incidence and severity of adverse events. All of the subjects underwent a unilateral thalamotomy targeting the ventral intermediate nucleus. At the baseline assessment, the estimated marginal mean of the Clinical Rating Scale for Tremor total score was 58.3 ± 3.6, and this improved after treatment to 23.1 ± 6.4 at a 12-month follow-up assessment. A total of 50 adverse events were recorded, and 2 were defined as serious. The most common intraoperative adverse events were nausea and headache. The most frequent postoperative adverse events were paresthesia and equilibrium disorder. Most of the adverse events were mild and usually disappeared within a few days. Our findings suggest that magnetic resonance-guided focused ultrasound for the treatment of essential tremor is effective, with a good safety profile, for patients in Chinese mainland.

Gray matter alterations in tremor-dominant Parkinson's disease after MRgFUS thalamotomy are correlated with tremor improvement: a pilot study.

Background: Regional differences in gray matter volume (GMV) have been reported to be a reliable marker for diagnosing Parkinson's disease (PD). This study aimed to explore the clinical value of GMV to assess magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy as a treatment for tremor-dominant PD (TDPD). Methods: Nine TDPD patients with MRgFUS thalamotomy were recruited for structural magnetic resonance image (MRI) scanning and clinical score evaluation. GMV was calculated. To investigate changes after treatment, voxel- and region of interest (ROI)-wise GMV analyses were performed. Then, GMV with significant differences was extracted from patients to investigate its dynamic alterations by one-way repeated-measures analysis of variance (ANOVA). The nonparametric Spearman rank correlation analysis was used to evaluate the relationship between GMV alterations and tremor improvement after thalamotomy. Results: Tremors were significantly relieved after MRgFUS thalamotomy in nine patients (P<0.05). The treated hand tremor scores improved 74.82% on average in patients from pre-operation to 12 months post-operation. Voxel-wise analysis at the cluster level showed a significant decrease in GMV in the left middle occipital gyrus (MOG) [t=11.81, voxel-level P<0.001, cluster-level Pfamily-wise error (FWE) <0.05] and an increase in GMV in the left precentral gyrus (PreCG) (t=7.99, voxel-level P<0.001, cluster-level PFWE <0.05) in TDPD patients from preoperative to 12 months post-operation, which was significantly correlated with tremor scores (rho =0.346-0.439, P<0.05). ROI-wise analysis showed that GMV related to MRgFUS thalamotomy was associated with long-term structural alterations (P<0.05 with Bonferroni correction), including specific basal ganglia and related nuclei and cerebellum subregions. Conclusions: GMV can be used to reflect tremor improvement after MRgFUS thalamotomy and be helpful to better understand the distant effect of MRgFUS thalamotomy and the involvement of GMV in tremor control in TDPD. Trial Registration: ClinicalTrials.gov identifier: NCT04570046.