OBJECTIVETo discuss the clinical ultiliazation and significance of microembolus detection by transcranial Doppler (TCD) sonography in intracranial stenosis-occlusive disease.

DATA SOURCESAll related articles in this review were mainly searched from PubMed published in English from 1996 to 2012 using the terms of microembolic signal, transcranial Doppler, intracranial stenosis, stroke.

STUDY SELECTIONOriginal articles and reviews were selected if they were related to the clinical utilization of microembolus detection in intracranial stenosis-occlusive disease.

RESULTSIntracranial stenosis is a significant cause of cerebral emboli, and microembolus detection by TCD sonography were widely used in exploring the mechanisms of ischemic stroke with intracranial stenosis (including the middle cerebral artery stenosis and the vertebral-basilar stenosis), evaluating the prognosis of acute stroke, evaluating the therapeutic effects, and predicting the recurrent events of stroke.

CONCLUSIONMicroembolus detection by TCD sonography plays an important role in the cerebral ischemic stroke patients with intracranial stenosis.

Constriction, Pathologic ; diagnostic imaging ; Humans ; Intracranial Embolism ; diagnostic imaging ; Stroke ; diagnostic imaging ; Ultrasonography, Doppler, Transcranial ; methods

Clinically, non-contrastive computed tomography (NCCT) is used to quickly diagnose the type and area of ​​stroke, and the Alberta stroke program early computer tomography score (ASPECTS) is used to guide the next treatment. However, in the early stage of acute ischemic stroke (AIS), it's difficult to distinguish the mild cerebral infarction on NCCT with the naked eye, and there is no obvious boundary between brain regions, which makes clinical ASPECTS difficult to conduct. The method based on machine learning and deep learning can help physicians quickly and accurately identify cerebral infarction areas, segment brain areas, and operate ASPECTS quantitative scoring, which is of great significance for improving the inconsistency in clinical ASPECTS. This article describes current challenges in the field of AIS ASPECTS, and then summarizes the application of computer-aided technology in ASPECTS from two aspects including machine learning and deep learning. Finally, this article summarizes and prospects the research direction of AIS-assisted assessment, and proposes that the computer-aided system based on multi-modal images is of great value to improve the comprehensiveness and accuracy of AIS assessment, which has the potential to open up a new research field for AIS-assisted assessment.
Alberta ; Brain Ischemia/diagnostic imaging* ; Humans ; Ischemic Stroke ; Stroke/diagnostic imaging* ; Tomography, X-Ray Computed

Brain Ischemia ; Cardiomyopathy, Hypertrophic/diagnostic imaging* ; Hemorrhagic Stroke ; Humans ; Moyamoya Disease/diagnostic imaging* ; Stroke/etiology*

Aged ; Carotid Arteries ; diagnostic imaging ; Echocardiography ; Female ; Humans ; Male ; Middle Aged ; Stroke ; diagnosis ; diagnostic imaging

Cerebrovascular Disorders ; diagnostic imaging ; Clinical Medicine ; Humans ; Neuroradiography ; methods ; trends ; utilization ; Stroke ; diagnostic imaging

OBJECTIVETo determine the distribution of aortic arch and intra/extracranial cerebral arterial atherosclerosis in Chinese patients who had suffered acute ischemic strokes.

METHODSEighty-nine patients with acute ischemic strokes were included in this study. Transesophageal echocardiography (TEE) was used to evaluate potential sources of embolisms in the aortic arch and in the heart; duplex ultrasound was used for the carotid artery; and intracranial Doppler (TCD) imaging was used for the middle cerebral artery (MCA), anterior cerebral artery (ACA), posterior cerebral artery (PCA), and basilar artery (BA). An atherosclerotic lesion in the aortic arch was defined as normal (0); mild plaque (1); moderate plaque (2); and protruding plaque or mobile plaque (3). A lesion in the carotid artery was considered a plaque if the maximal carotid plaque thickness was 1.2 mm. TCD results were deemed abnormal if flow velocity was either greater or lower than normal, and, in the case of the MCA, if an asymmetry index above 21% was measured.

RESULTSOf the 89 patients, 52 (58.43%) patients showed evidence of aortic arch atherosclerosis (AAA), including 11 (12.36%) patients graded mild, 18 (20.22%) patients graded moderate, and 23 (25.84%) patients graded severe. Of the 23 patients with severe AAA, AAA was determined to be an important potential embolic source in 14 patients. Forty-nine (50.56%) patients had carotid arterial plaques (CAPs). The incidence of carotid plaques was higher among patients with AAA than among patients without AAA (71.15% vs 21.62%, OR = 3.291, 95% CI = 1.740 - 6.225, P < 0.001). TCD abnormalities affecting the MCA were found in 54 (60.67%) patients. Differences in incidence of TCD abnormalities between patients with AAA and without AAA (69.23% vs 48.65%) were not significant (OR = 1.423, 95% CI = 0.976 - 2.076, P = 0.05). There was a higher incidence of AAA in older, male patients with a history of diabetes and smoking.

CONCLUSIONSAAA is an important potential source of cerebral embolic strokes. The presence of carotid arterial plaques correlates with AAA incidence. Most of carotid artery lesion were plaques other than severe stenosis, it may be the character of carotid atherosclerosis of stroke patients. It appears that atherosclerosis does not mainly occur in the intracranial arteries in stroke patients as thought before. Aged, male, diabetes, and smoking are important risk factors to the AAA.

Acute Disease ; Aged ; Aorta, Thoracic ; diagnostic imaging ; Aortic Diseases ; diagnostic imaging ; Arteriosclerosis ; diagnostic imaging ; Brain Ischemia ; diagnostic imaging ; Female ; Humans ; Intracranial Arteriosclerosis ; diagnostic imaging ; Intracranial Embolism ; diagnostic imaging ; Male ; Middle Aged ; Stroke ; diagnostic imaging ; Ultrasonography

OBJECTIVESTo determine the relative value of transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) in exploring the potential embolic source (PES) in heart and aortic arch and to study the clinical significance of aortic arch atherosclerosis (AAA).

METHODSForty-nine patients with cerebral embolism were included in this study. TEE and TTE were used to evaluate the potential source of emboli in aortic arch, heart and duplex in the carotid artery. An atherosclerotic lesion of the aortic arch was defined as normal, mild plaque, moderate plaque, and protruding plaque or mobile plaque.

RESULTSOf the 49 patients, 31 (63%) patients showed evidence of AAA: 7 (14.1%) patients were mild, 9 (18.4%) were moderate and 15 (30.6%) were severe. In those 15 patients, 11 had neither severe ICAA nor heart disease. Thirty-three patients had internal carotid arterial atherosclerosis (ICAA). The potential sources of embolization of heart and aortic arch is 48.98% by TEE, but only 18.4% by TTE; 9 patients had heart disease. Age and ICAA were significantly correlated with AAA.

CONCLUSIONAt present, TEE is a better method for exploring atherosclerotic lesions in the thoracic aorta. AAA is an important potential source of cerebral embolic stroke.

Adult ; Aged ; Aorta, Thoracic ; diagnostic imaging ; pathology ; Aortic Diseases ; complications ; diagnostic imaging ; Arteriosclerosis ; diagnostic imaging ; Carotid Arteries ; diagnostic imaging ; pathology ; Echocardiography ; Echocardiography, Transesophageal ; Female ; Heart Diseases ; diagnostic imaging ; Humans ; Male ; Middle Aged ; Myocardium ; pathology ; Risk Factors ; Stroke ; diagnostic imaging ; etiology

Heart Failure/diagnostic imaging* ; Humans ; Magnetic Resonance Imaging ; Stroke Volume ; Ventricular Function, Left

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

To evaluate the white-matter integrity and its correlation with cognitive function in patients with mild cognitive impairment (MCI) complicated with lacunar infarctions (LI) by diffusion tensor imaging (DTI) of magnetic resonance (MR).
 Methods: Twenty-six patients with MCI were selected including 14 patients with combined LI and 12 patients without combined LI, and 16 healthy volunteers were recruited as normal control. All subjects completed cognitive function assessment and DTI sequence of MR. Factional anisotropy (FA) and mean diffusivity (MD) values among the MCI with LI group (MCI-LI), the MCI without LI group (MCI-non LI), and the normal control group (NC) were compared, and the correlation between DTI parameters and cognition was determined by multiple linear stepwise regression.
 Results: Compared with the MCI-non LI group, the FA values were significantly decreased (P<0.05) and MD values were significantly increased (P<0.05) in the white matter fiber bundles (such as the left hippocampus of the cingulate tract, the frontal fascicle of the corpus callosum, the right inferior frontal occipital fascicle, and the right superior longitudinal fascicle) in the MCI-LI group. In the MCI-LI group, the FA value of right cingulate gyrus was significantly correlated with Activity of Daily Living Scale (ADL) score (B=-50.2, 95% CI -77.7 to -22.7, P=0.003); the FA value of left anterior thalamic radiation (B=443.8, 95% CI 222.9 to 664.8, P=0.001) and MD value of left inferior longitudinal tract (B=-318.5, 95% CI -534.7 to -102.3, P=0.009) were significantly correlated with Wechsler digit symbol substitution (WDSS) score; the FA value of left superior temporal lobe longitudinal tract was significantly correlated with Backward Digit Span (BDSP) score (B=12.5, 95% CI 1.5 to 23.4, P=0.030).
 Conclusion: The integrity of white matter is significantly destroyed in MCI patients with LI than that in MCI patients without LI, and there is a correlation between cognitive function and DTI parameters in some white matter tracts in MCI patients with LI.
Anisotropy ; Brain ; Cognitive Dysfunction ; diagnostic imaging ; Diffusion Magnetic Resonance Imaging ; Diffusion Tensor Imaging ; Humans ; Neuropsychological Tests ; Stroke, Lacunar ; White Matter