High signal-intensity abnormalities in susceptibility-weighted imaging for primary intracerebral hemorrhage

Abstract

Purpose: To identify the regularity of signal evolution of intracerebral hemorrhage on susceptibility-weighted imaging (SWI) at different stages compared with T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI).

Methods: We retrospectively evaluated a series of 365 patients who underwent T1WI, T2WI, and SWI examination simultaneously or sequentially in our hospital from January 2015 to May 2017. Two neuroradiologists assessed the images and discrepancies between their interpretations were resolved by consensus. Statistical analysis was performed using Chi-squared and Kappa tests.

Results: Of the 365 patients on SWI sequence, 94 were enrolled. SWI detected the cases at different stages; T1WI detected 89 cases and T2WI detected 91 cases. The signal intensity of intracerebral hemorrhage on SWI was significantly associated with T1WI imaging and T2WI (χ²?=?4.651; p?<?0.05; χ²?=?26.396; p?<?0.01, respectively), especially at the late subacute stage. There was moderate consistency between the signal intensity of intracerebral hemorrhage on T2WI and SWI (Kappa coefficient = 0.530).

Conclusion: Intracerebral hemorrhage has a varied appearance on SWI, and the evolution of signal of intracerebral hemorrhage on SWI sequence is influenced by T1WI and T2WI. Hematoma detection should be closely combined with clinical manifestation.     

Abnormal signals on proton density-weighted MRI of the superior cerebellar peduncle in progressive supranuclear palsy

OBJECTIVE: To assess MRI signal abnormalities of the superior cerebellar peduncle (SCP) in progressive supranuclear palsy (PSP) patients. MATERIAL AND METHODS: Signal changes were examined on proton density-weighted images (PDWI) and on T2-weighted images (T2WI) of SCP in 9 PSP patients, and findings were compared to those in 20 Parkinson's disease patients and 20 age-matched control subjects. RESULTS: We observed effacement or lack of clarity of the low signal on PDWI in SCP in 4 of 9 PSP patients, but not in any of the Parkinson's disease patients or control subjects. These signal changes were not observed on T2WI. CONCLUSIONS: The signal changes on PDWI may be a specific finding reflecting demyelination and gliosis of SCP in PSP. Our findings suggest that evaluation of SCP on PDWI may be helpful in the diagnosis of PSP patients.     

磁共振不同成像序列对大脑中动脉主干闭塞的诊断价值

目的研究磁共振（MRI）不同成像序列在诊断大脑中动脉（MCA）主干闭塞中的价值。方法选择发病48h内行头颅MRI检查，并选择磁共振血管成像（MRA）显示单侧MCA主干闭塞的患者作为研究对象，观察T1加权像、T2加权像、FLAIR成像的MCA主干闭塞征象。结果共有41例脑梗死或TIA患者入组，T2WI成像显示侧裂池血管流空影减少和FLAIR成像侧裂池显示等或高信号血管影对MCA主干闭塞的诊断灵敏度较其他3个征象高，分别为78．0％和75．6％，诊断特异度均为100％，两者的诊断正确率较其他3个征象高。结论所有患者至少观察到1个MCA主干闭塞的MRI征象，其中T2WI成像显示侧裂池血管流空影减少和FLAIR成像显示侧裂池等或高信号血管影对MCA主干闭塞的诊断价值高于其他MRI征象。     

Hyperintense Basal Ganglia on T1-Weighted Magnetic Resonance Images in a Patient With Common Variable Immunodeficiency Associated With Elevated Serum Manganese

The authors report on a 32-year-old man with common variable immunodeficiency and high signal intensity in basal ganglia on T1-weighted images. No signal alteration on T2-weighted and postcontrast images was observed. The patient had elevated levels of manganese in the serum. The authors conclude that the unusual hyperintensity in the basal ganglia area on T1-weighted images resulted from manganese deposition due to liver dysfunction.     

Unexpected neurological sequelae following propofol anesthesia in infants: Three case reports

Propofol is a widely used hypnotic agent for induction and maintenance of pediatric anesthesia with a well known safety profile. Experimental in vitro studies suggest that propofol may be toxic to developing neurons. We report the cases of three infants who underwent surgery before 2 months of age for different benign pathologies. Propofol was used for induction and maintenance of anesthesia in all cases. The three patients developed convulsions with similar clinical characteristics (cluster of recurrent clinical and subclinical seizures) between the 23th and 30th hours following anesthesia. Clinical and electroencephalographic improvement was obtained between the third and fourth day of management in pediatric intensive care unit. The seizures never recurred, and the three patients underwent further uneventful general anesthesia without propofol. Follow-up of the three patients disclosed unexpected neurological dysfunction: progressive microcephaly (head circumferences were normal at birth), developmental impairment with cognitive and behavioural disturbances in two cases, and bilateral symmetrical white-matter abnormalities on cerebral magnetic resonance imaging. Conclusion: The causal relationship between propofol anesthesia and the neurological symptoms of our patients remains difficult to ascertain, but we believe that pediatricians, anesthetists and intensive care-givers should be aware of this possible adverse reaction that has never been described before.     

磁共振指导下脑微出血的精准诊疗

脑微出血（cerebral microbleeds,CMBs）作为脑小血管病的一种,与各种血管危险因素密切 相关,其中脑叶CMBs还与淀粉样脑血管病相关。CMBs不仅提高了复发症状性脑出血的风险,还可能引 起认知障碍甚至痴呆。本文主要就CMBs在磁共振磁敏感序列的影像特点和诊断标准等方面进行综 述,通过神经影像学检查方法提高CMBs诊断的准确率,为CMBs的精准诊断和治疗提供重要依据。     

Peri-electrode edema after deep brain stimulation

Peri-electrode edema can occur after deep brain stimulation (DBS). The diagnosis and management of peri-electrode edema may be challenging. We herein report non-infectious peri-electrode edema after the placement of DBS electrodes in patients with Parkinson’s disease (PD). Fifteen patients who underwent DBS surgery between 2010 and 2018 at Sapporo Medical University were included to identify post-operative peri-electrode edema. Pre- and post-operative CT and MRI were retrospectively analyzed.Six patients showed hyperintensity around the electrodes on FLAIR/T2 MRI without neurological deficits. Two patients showed limited FLAIR and DWI hyperintensities in deep white matter, and microvessels may have been occluded in these patients. In five patients, MRI revealed extensive FLAIR or T2 hyperintensity in surface white matter around the electrodes without vessel injury, whereas DWI showed no abnormal signals. The eosinophil count was increased in one of these five patients. Peri-electrode edema after DBS surgery is not an uncommon phenomenon, and includes two types: (1) limited edema in deep white matter and (2) extensive edema in surface white matter. Different mechanisms may be associated with these types of edemas.     

Tianeptine reverses stress-induced asymmetrical hippocampal volume and N-acetylaspartate loss in rats: An in vivo study

Stress-induced hippocampal volume loss and decrease in N-acetylaspartate (NAA) level have been reported to be associated with impaired neural plasticity and neuronal damage in adults. Accordingly, reversing structural and metabolite damage in the hippocampus may be a desirable goal for antidepressant therapy. The present study investigated the effects of tianeptine on chronic stress-induced hippocampal volume loss and metabolite alterations in vivo in 24 Sprague-Dawley rats. Rats were subjected to a consecutive 28-day forced swimming test stress. Tianeptine (50 mg/kg) or saline was administered intragastrically 4 h after swimming each day. Spontaneous behaviors, serum corticosterone concentration, hippocampal volume and NAA level were evaluated after stress. Chronic tianeptine treatment counteracted the chronic stress-induced suppression of spontaneous behaviors, elevated serum corticosterone concentration, reduced hippocampal volume and decreased NAA level. Moreover, we found asymmetrical right–left hippocampal volume loss in stressed rats, with the left hippocampus more sensitive to chronic stress than the right hippocampus. In addition, stressed rats showed a decreased level of hippocampal metabolites, without significant loss of hippocampal volume. These findings provide experimental evidence for impaired structural plasticity of the brain being an important feature of depressive illness and suggest that prophylactic tianeptine treatments could reverse structural changes in brain. The structural and neurochemical alterations in the hippocampus may be valuable indexes for evaluating the prophylactic and curative effect of antidepressant treatments in depressive and stress-related disorders.     

Central vein sign and paramagnetic rim sign: From radiologically isolated syndrome to multiple sclerosis

The widespread use of magnetic resonance imaging (MRI) has led to an increase in incidental findings in the central nervous system. Radiologically isolated syndrome (RIS) is a condition where imaging reveals lesions suggestive of demyelinating disease without any clinical episodes consistent with multiple sclerosis (MS). The prognosis for RIS patients is uncertain, with some remaining asymptomatic while others progress to MS. Several risk factors for disease progression have been identified, including male sex, younger age at diagnosis, and spinal cord lesions. This article reviews two promising biomarkers, the central vein sign (CVS) and the paramagnetic rim sign (PRS), and their potential role in the diagnosis and prognosis of MS and RIS. Both CVS and PRS have been shown to be accurate diagnostic markers in MS, with high sensitivity and specificity, and have been useful in distinguishing MS from other disorders. Further research is needed to validate these findings and determine the clinical utility of these biomarkers in routine practice.     

缺血性卒中患者脑微出血的相关因素分析

目的 探讨缺血性卒中患者发牛脑微出血(CMBs)的相关因素. 方法 对85例急性缺血性卒中患者进行磁共振检查,其中包括梯度回波T2加权成像(GE-T2~*WI),并对患者的临床资料和影像学特点进行分析. 结果 26例(30.6%)患者中共检出CMBs 124个,每位患者的CMBs数目在1～16个之间.CMBs在基底节丘脑区和皮质一皮质下区分布较多,在幕下区较少见.发生在脑十的CMBs可有相关症状及体征.CMBs数目与年龄、腔隙性梗死数目及白质疏松程度评分有相关性(r=0.243,P=0.025;r=337,P=0.002;r=0.438,P=0.000).CMBs在GE-T2~*WI上显影良好,部分CMBs可在自旋叫波(SE)T2WI及DWI序列上显影. 结论 CMBs是脑微小血管病变标志,主要预测因素有高龄、多发腔隙性梗塞和白质疏松.     

A meta-analysis showing that high signal intensity on T2-weighted MRI is associated with poor prognosis for patients with cervical spondylotic myelopathy

We used PubMed, Medline, and EMBASE to conduct a meta-analysis to determine the significance of high signal intensity on T2-weighted MRI for predicting postoperative prognosis in patients with cervical spondylotic myelopathy (CSM). Although patients with CSM with high signal intensity on T2-weighted MRI usually had a poor prognosis even after undergoing surgery, some researchers have argued recently that high-intensity signals are not associated with postoperative prognosis. Data consistent with the inclusion criteria of this study were cited for meta-analysis using Review Manager 5 Software. The postoperative recovery ratio specified by the Japanese Orthopedic Association (JOA) was assessed using the weighted mean difference (WMD) method. Five articles (one prospective; four retrospective) involving 309 patients with CSM were included. The aggregate WMD with regard to the postoperative JOA recovery ratio between the T2-weighted high signal intensity positive (+) group and the T2-weighted high signal intensity negative (-) group was -6.56, and the 95% confidence interval (CI) was -12.15 to -0.97 (p=0.02). Thus, we concluded that in patients with CSM, the postoperative JOA recovery ratio in the T2-weighted (+) group was lower than that in the T2-weighted (-) group.     

Significance of the T2*-weighted gradient echo brain imaging in patients with infective endocarditis

Background

Although aneurysm formation accompanying parenchymal hemorrhage is one of devastating complications in the central nerves system (CNS), imaging studies of the brain are not routinely warranted in patients with infective endocarditis (IE). To assess the clinical importance for detecting silent lesions in the central nervous system, we investigated hypointense signal spots detected on the brain T2*-weighted MR imaging in patients with IE.

Methods and results

Eleven patients with IE were retrospectively reviewed. Seven patients (63.6%) showed hypointense signal spots on T2*-weighted MR images. The number of hypointense signal spots increased within only a few weeks in five patients.

Conclusion

The brain T2*-weighted MR imaging in patients with IE may have a potential role to detect CNS lesions with clinical significance of potentially high risk of intracranial hemorrhage. T2*-weighted hypointense signal spots may be specific to brain involvement, and be quite useful in monitoring CNS lesions associated with IE, even if they are asymptomatic.     

White matter hyperintensities and rating scales—observer reliability varies with lesion load

Abstract.Background: Cerebral white matter hyperintensities (WMHs) are common in older people. Their presence correlates with cognitive decline and vascular risk factors. Various scales have been developed to quantify the amount and type of WMH, but with few observer reliability studies. We evaluated several scales in different cohorts to determine their observer reliability.Methods: Two observers independently rated T2-weighted MR images from five groups (total n = 494: normal older subjects [97]; patients with minor stroke [221]; young insulin dependent diabetics [141]; maturity onset diabetics [10]; and hepatic encephalopathy [25]), using seven rating scales (Breteler, Fazekas, Longstreth, Mirsen, Shimada, Van Swieten and Wahlund). Inter-observer reliability was determined using Kappa statistics.Results: Patients with maturity onset diabetes had the most WMHs and young insulin-dependent diabetics the least. Inter-observer reliability varied with the amount of WMH. In maturity onset diabetics (most WMHs) the weighted Kappas were: Breteler 0.74; Fazekas 0.89 and 0.72; Van Swieten 0.76 and 0.88; and in young insulin-dependent diabetics (least WMH): Breteler 0.3; Fazekas 0.2 and 0.24; Van Swieten 0.39 and 0.30. These findings were consistent across the groups.Conclusion: WMH rating scale performance varied with WMH prevalence, and hence with subject cohort. In patients with most WMHs the apparent better kappas may reflect a ceiling effect rather than true better agreement. These factors should be considered in studies where risk factors for, or associations with, the early development of WMHs are being determined.     

Evaluating whole-brain tissue-property changes in MRI-negative pharmacoresistant focal epilepsies using MR fingerprinting

Objective

We aim to quantify whole-brain tissue-property changes in patients with magnetic resonance imaging (MRI)–negative pharmacoresistant focal epilepsy by three-dimensional (3D) magnetic resonance fingerprinting (MRF).

Methods

We included 30 patients with pharmacoresistant focal epilepsy and negative MRI by official radiology report, as well as 40 age- and gender-matched healthy controls (HCs). MRF scans were obtained with 1 mm³ isotropic resolution. Quantitative T1 and T2 relaxometry maps were reconstructed from MRF and registered to the Montreal Neurological Institute (MNI) space. A two-sample t test was performed in Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (FSL) to evaluate significant abnormalities in patients comparing to HCs, with correction by the threshold-free cluster enhancement (TFCE) method. Subgroups analyses were performed for extra-temporal epilepsy/temporal epilepsy (ETLE/TLE), and for those with/without subtle abnormalities detected by morphometric analysis program (MAP), to investigate each subgroup's pattern of MRF changes. Correlation analyses were performed between the mean MRF values in each significant cluster and seizure-related clinical variables.

Results

Compared to HCs, patients exhibited significant group-level T1 increase ipsilateral to the epileptic origin, in the mesial temporal gray matter (GM) and white matter (WM), temporal pole GM, orbitofrontal GM, hippocampus, and amygdala, with scattered clusters in the neocortical temporal and insular GM. No significant T2 changes were detected. The ETLE subgroup showed a T1-increase pattern similar to the overall cohort, with additional involvement of the ipsilateral anterior cingulate GM. The subgroup of MAP+ patients also showed a T1-increase pattern similar to the overall cohort, with additional cluster in the ipsilateral lateral orbitofrontal GM. Higher T1 was associated with younger seizure-onset age, longer epilepsy duration, and higher seizure frequency.

Significance

MRF revealed group-level T1 increase in limbic/paralimbic structures ipsilateral to the epileptic origin, in patients with pharmacoresistant focal epilepsy and no apparent lesions on MRI, suggesting that these regions may be commonly affected by seizures in the epileptic brain. The significant association between T1 increase and higher seizure burden may reflect progressive tissue damage.     

磁共振成像对脑静脉畸形的诊断价值

目的 探讨磁共振成像各种方法对脑静脉畸形的诊断价值。方法 收集本院6例脑静脉畸形病例，均进行过磁共振T1WI、T2WI扫描，其中部分病例做过DWI、T2FLAIR、MRA、MRV、T1WI增强扫描及DSA。结果 幕上4例，幕下2例，T1WI、T2WI表现：引流静脉均为流空的低信号，深髓静脉为细条状长T1、长T2信号。其中1例DWI引流静脉及深髓静脉区域低信号；1例T2 FLAIR引流静脉流空的低信号，深髓静脉高信号；2例MRA均阴性，但MRV显示深髓静脉汇入引流静脉；2例T1 WI增强扫描：深髓静脉呈轮辐状汇入引流静脉；1例DSA：动脉期阴性，静脉期见典型的“海蛇头”征。结论 磁共振能明确诊断脑静脉畸形，T1WI增强扫描及MRV均较敏感，DSA为诊断脑静脉畸形金标准。     

磁共振成像对脑静脉畸形的诊断价值

目的 探讨磁共振成像各种方法对脑静脉畸形的诊断价值.方法 收集本院6例脑静脉畸形病例,均进行过磁共振T1WI、T2WI扫描,其中部分病例做过DWI、T2FLAIR、MRA、MRV、T1WI增强扫描及DSA. 结果幕上4例,幕下2例,T1WI、T2WI表现:引流静脉均为流空的低信号,深髓静脉为细条状长T1、长T2信号.其中1例DWI引流静脉及深髓静脉区域低信号;1例T2FLAIR引流静脉流空的低信号,深髓静脉高信号;2例MRA均阴性,但MRV显示深髓静脉汇入引流静脉;2例TIWI增强扫描:深髓静脉呈轮辐状汇入引流静脉;1例DSA:动脉期阴性,静脉期见典型的"海蛇头"征.结论 磁共振能明确诊断脑静脉畸形,T1WI增强扫描及MRV均较敏感,DSA为诊断脑静脉畸形金标准.     

A comparison of the sensitivity of monthly unenhanced and enhanced MRI techniques in detecting new multiple sclerosis lesions

In this longitudinal study, the sensitivities of three magnetic resonance imaging techniques for detecting the appearance of new lesions in multiple sclerosis (MS) were evaluated and compared. Dual-echo conventional spin-echo (CSE), fast fluid-attenuated inversion recovery (fast-FLAIR) and post-contrast T1-weighted scans were obtained on four occasions, each separated by 28 days, from 18 patients with relapsing-remitting MS using a 1.5-T machine. New lesions seen using each sequence during the follow-up were counted by agreement by four observers in two stages (stage 1: random review of complete sets of scans from each technique; stage 2: side-by-side review with a ‘retrospective’ count of new lesions). At stage 1, 1.44 new lesions per patient per month were detected on CSE scans, 1.88 on fast-FLAIR (31% more than CSE) and 2.07 on post-contrast T1-weighted scans (44% more than CSE) (P = 0.03). Differences were, however, reduced after stage 2: fast-FLAIR detected 29% and post-contrast T1-weighted scans detected 31% more new lesions than CSE (P = 0.08). The combination of fast-FLAIR and post-contrast scans detected 144 new lesions, whilst the usual combination of CSE and post-contrast scans detected 133 new lesions. This study indicates that enhanced MRI remains the most sensitive method for detecting ‘active’ lesions in MS and that fast-FLAIR may be used when monitoring short-term disease activity in MS, either natural or modified by treatment. Received: 11 February 1998 Received in revised form: 5 May 1998 Accepted: 18 May 1998     

Increased signal intensity on postoperative T2-weighted axial images in cervical spondylotic myelopathy: Patterns of changes and associated impact on outcomes

Although T2-weighted axial magnetic resonance imaging (MRI) has strength in demonstrating morphologic characteristics of the spinal cord in cervical spondylotic myelopathy (CSM), no study has investigated postoperative changes. We aimed to assess postoperative changes on T2-weighted axial MRI using the classification system based on axial imaging in cervical compressive myelopathy (Ax-CCM) and associated impact on outcome in CSM. In total, 250 patients with CSM who underwent decompressive surgery with preoperative and postoperative MRI were included. At first, we investigated the presence of increased signal intensity (SI) in cervical spinal cord on T2-weighted sagittal images. Next, the increased SI was assessed using Ax-CCM on T2weighted axial images. The classifications were type 0, no-signal abnormality; single-level type 1, diffuse; single-level type 2, fuzzy focal; single-level type 3, discrete focal; and two-level. The recovery rates (RRs) of modified Japanese Orthopaedic Association (mJOA) score were evaluated from 5 to 10 months postoperatively. Eighty-seven patients (34.8%) exhibited postoperative changes. Most of postoperative changes were in single-level type 1 and 2. Patterns of changes were resolution, reduced extent, or transition to discrete margin. The most common pattern was resolution in type 1 (23.9%) and transition to discrete margin in type 2 (46.5%). In each group, resolution showed the best RR, but insignificantly (p > 0.05).