Among numerous medical imaging modalities, diffusion weighted imaging (DWI) is extremely sensitive to acute ischemic stroke lesions, especially small infarcts. However, magnetic resonance imaging is time-consuming and expensive, and it is also prone to interference from metal implants. Therefore, the aim of this study is to design a medical image synthesis method based on generative adversarial network, Stroke-p2pHD, for synthesizing DWI images from computed tomography (CT). Stroke-p2pHD consisted of a generator that effectively fused local image features and global context information (Global_to_Local) and a multi-scale discriminator (M ²Dis). Specifically, in the Global_to_Local generator, a fully convolutional Transformer (FCT) and a local attention module (LAM) were integrated to achieve the synthesis of detailed information such as textures and lesions in DWI images. In the M ²Dis discriminator, a multi-scale convolutional network was adopted to perform the discrimination function of the input images. Meanwhile, an optimization balance with the Global_to_Local generator was ensured and the consistency of features in each layer of the M ²Dis discriminator was constrained. In this study, the public Acute Ischemic Stroke Dataset (AISD) and the acute cerebral infarction dataset from Yantaishan Hospital were used to verify the performance of the Stroke-p2pHD model in synthesizing DWI based on CT. Compared with other methods, the Stroke-p2pHD model showed excellent quantitative results (mean-square error = 0.008, peak signal-to-noise ratio = 23.766, structural similarity = 0.743). At the same time, relevant experimental analyses such as computational efficiency verify that the Stroke-p2pHD model has great potential for clinical applications.
Humans ; Tomography, X-Ray Computed/methods* ; Diffusion Magnetic Resonance Imaging/methods* ; Cerebral Infarction/diagnostic imaging* ; Stroke/diagnostic imaging* ; Neural Networks, Computer ; Image Processing, Computer-Assisted/methods* ; Algorithms

Cerebral edema is characterized by fluid accumulation, and the glymphatic system (GS) plays a pivotal role in regulating fluid transport. Using the Tenecteplase system, magnesium salt of salvianolic acid B/ginsenoside Rg1 (SalB/Rg1) was injected intravenously into mice 4.5 h after middle cerebral artery occlusion and once every 24 h for the following 72 h. GS function was assessed by Evans blue imaging, near-infrared fluorescence region II (NIR-II) imaging, and magnetic resonance imaging (MRI). SalB/Rg1 had significant effects on reducing the infarct volume and hemorrhagic transformation score, improving neurobehavioral function, and protecting tissue structure, especially inhibiting cerebral edema. Meanwhile, the influx/efflux drainage of GS was enhanced by SalB/Rg1 according to NIR-II imaging and MRI. SalB/Rg1 inhibited matrix metalloproteinase-9 (MMP-9) activity, reduced cleaved β-dystroglycan (β-DG), and stabilized aquaporin-4 (AQP4) polarity, which was verified by colocalization with CD31. Our findings indicated that SalB/Rg1 treatment enhances GS function and attenuates cerebral edema, accompanying the regulation of the MMP9/β-DG/AQP4 pathway.
Animals ; Ginsenosides/administration & dosage* ; Brain Edema/etiology* ; Male ; Benzofurans/administration & dosage* ; Glymphatic System/diagnostic imaging* ; Mice ; Infarction, Middle Cerebral Artery/drug therapy* ; Aquaporin 4/metabolism* ; Disease Models, Animal ; Mice, Inbred C57BL ; Matrix Metalloproteinase 9/metabolism* ; Neuroprotective Agents/pharmacology* ; Depsides

In animal experiments, ischemic stroke is usually induced through middle cerebral artery occlusion (MCAO), and quality assessment of this procedure is crucial. However, an accurate assessment method based on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is still lacking. The difficulty lies in the inconsistent preprocessing pipeline, biased intensity normalization, or unclear spatiotemporal uptake of FDG. Here, we propose an image feature-based protocol to assess the quality of the procedure using a 3D scale-invariant feature transform and support vector machine. This feature-based protocol provides a convenient, accurate, and reliable tool to assess the quality of the MCAO procedure in FDG PET studies. Compared with existing approaches, the proposed protocol is fully quantitative, objective, automatic, and bypasses the intensity normalization step. An online interface was constructed to check images and obtain assessment results.
Animals ; Fluorodeoxyglucose F18 ; Infarction, Middle Cerebral Artery/diagnostic imaging* ; Positron-Emission Tomography/methods*

Diffusion-weighted imaging (DWI) is currently the most sensitive technique to diagnose early ischemic stroke. DWI signal hyperintensity is usually considered to suggest irreversible infarct core, but recent studies demonstrated that DWI hyperintensity signal could be reversible on small embolic lesions. Herein we present a case in a 63-year-old male patient, who was admitted to the emergency department with altered mental status and complaint of weakness in the left arm and leg 6.8 h prior to the admission. Emergency cranial magnetic resonance imaging (MRI) and angiography (MRA) revealed occlusion of his right middle cerebral artery (MCA) and large lesions on DWI. The patient underwent intra-artery thrombectomy after evaluation in spite of the large volume of the DWI lesions up to 91.5 mL at the baseline. His right MCA was recanalized at 8.5 h from symptom onset. One week after the procedure, the patient showed reduced DWI lesion volume to 11.58 mL. In this case we observed the reversibility of a large lesion of the anterior artery circulation presenting with hyperintensity on DWI, suggesting that the clinical implication of DWI hyperintensity should be interpreted with caution, and a large volume of baseline DWI hyperintensity may not be a contraindication to thrombectomy. This conclusion, however, awaits further validation by future large-scale randomized controlled trials.
Diffusion Magnetic Resonance Imaging ; Humans ; Infarction, Middle Cerebral Artery ; diagnostic imaging ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Stroke ; Thrombectomy

Adult ; Cerebral Infarction ; diagnosis ; diagnostic imaging ; etiology ; Heart Atria ; diagnostic imaging ; pathology ; Humans ; Magnetic Resonance Imaging ; Male ; Myxoma ; complications ; diagnostic imaging

Acute Disease ; Adult ; Cerebral Infarction ; diagnosis ; diagnostic imaging ; Fabry Disease ; diagnosis ; diagnostic imaging ; Humans ; Magnetic Resonance Imaging ; Male

OBJECTIVE: The authors applied maximum external decompression for malignant hemispheric infarction and investigated the functional outcome according to the patient age.METHODS: Twenty-five patients with malignant hemispheric infarction were treated using a hemicraniectomy with maximum external decompression, comprising a larger (>14cm) hemicraniectomy, resection of the temporalis muscle and its fascia, spaciously expansive duraplasty, and approximation of the skin flap. The medical and diagnostic imaging records for the patients were reviewed, and 1-year functional outcome data obtained for the younger group (aged ≤ 60 years) and elderly group (aged > 60 years).RESULTS: The patients (n=25) who underwent maximum surgical decompression revealed a minimal mortality rate (n=2, 8.0%). The patients (n=14) in the younger group all survived with mRS scores of 2 (n=1, 7.1%), 3 (n=7, 50.0%), 4 (n=3, 21.4%), or 5 (n=3, 21.4%). A majority of the younger patients (57.1% with mRS ≤3) lived with functional independence. When the 1-year mRS scores were dichotomized between favorable (mRS ≤3) and unfavorable (mRS ≥4) outcomes, the younger group had significantly more patients with a favorable outcome than the elderly group (57.1% versus 9.1%, p=0.033). In contrast, in the elderly group, most patients showed unfavorable outcomes with the mRS scores of 4 (n=5, 45.5%), 5 (n=3, 27.3%), or 6 (n=2, 18.2%), whereas only one patient showed favorable outcome (mRS 3). A majority of the elderly patients (45.5% with mRS 4) survived with moderately severe disability.CONCLUSION: For malignant hemispheric infarction, a hemicraniectomy with maximum external decompression was found to considerably increase survival with a favorable outcome in functional independence (mRS ≤3) for younger patients aged ≤60 years. It can be optimal surgical treatment for younger patients.
Aged ; Cerebral Infarction ; Decompression ; Decompression, Surgical ; Diagnostic Imaging ; Fascia ; Humans ; Infarction ; Mortality ; Skin ; Treatment Outcome

Stroke at the acute stage is a major cause of disability in adults, and is associated with dysfunction of brain networks. However, the mechanisms underlying changes in brain connectivity in stroke are far from fully elucidated. In the present study, we investigated brain metabolism and metabolic connectivity in a rat ischemic stroke model of middle cerebral artery occlusion (MCAO) at the acute stage using F-fluorodeoxyglucose positron emission tomography. Voxel-wise analysis showed decreased metabolism mainly in the ipsilesional hemisphere, and increased metabolism mainly in the contralesional cerebellum. We used further metabolic connectivity analysis to explore the brain metabolic network in MCAO. Compared to sham controls, rats with MCAO showed most significantly reduced nodal and local efficiency in the ipsilesional striatum. In addition, the MCAO group showed decreased metabolic central connection of the ipsilesional striatum with the ipsilesional cerebellum, ipsilesional hippocampus, and bilateral hypothalamus. Taken together, the present study demonstrated abnormal metabolic connectivity in rats at the acute stage of ischemic stroke, which might provide insight into clinical research.
Acute Disease ; Animals ; Brain ; diagnostic imaging ; metabolism ; Brain Mapping ; Disease Models, Animal ; Fluorodeoxyglucose F18 ; Glucose ; metabolism ; Infarction, Middle Cerebral Artery ; diagnostic imaging ; metabolism ; Male ; Neural Pathways ; diagnostic imaging ; metabolism ; Positron-Emission Tomography ; Radiopharmaceuticals ; Random Allocation ; Rats, Sprague-Dawley

Positron emission tomography (PET) imaging of functional metabolism has been widely used to investigate functional recovery and to evaluate therapeutic efficacy after stroke. The voxel intensity of a PET image is the most important indicator of cellular activity, but is affected by other factors such as the basal metabolic ratio of each subject. In order to locate dysfunctional regions accurately, intensity normalization by a scale factor is a prerequisite in the data analysis, for which the global mean value is most widely used. However, this is unsuitable for stroke studies. Alternatively, a specified scale factor calculated from a reference region is also used, comprising neither hyper- nor hypo-metabolic voxels. But there is no such recognized reference region for stroke studies. Therefore, we proposed a totally data-driven automatic method for unbiased scale factor generation. This factor was generated iteratively until the residual deviation of two adjacent scale factors was reduced by < 5%. Moreover, both simulated and real stroke data were used for evaluation, and these suggested that our proposed unbiased scale factor has better sensitivity and accuracy for stroke studies.
Animals ; Computer Simulation ; Disease Models, Animal ; Female ; Fluorodeoxyglucose F18 ; Image Processing, Computer-Assisted ; methods ; Infarction, Middle Cerebral Artery ; diagnostic imaging ; Male ; Positron-Emission Tomography ; methods ; Rats ; Rats, Sprague-Dawley ; Stroke ; diagnostic imaging

Acupuncture Therapy ; Aged ; Aneurysm, Dissecting ; complications ; Brain ; diagnostic imaging ; pathology ; Cerebral Infarction ; etiology ; therapy ; Female ; Glasgow Coma Scale ; Humans ; Postoperative Complications ; etiology ; therapy ; Tomography, X-Ray Computed