Altered spontaneous brain activity patterns in hypertensive retinopathy using fractional amplitude of low-frequency fluctuations:a functional magnetic resonance imaging study

AIM:To study functional brain abnormalities in patients with hypertensive retinopathy(HR)and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations(fALFFs)method.METHODS:Twenty HR patients and 20 healthy controls(HCs)were respectively recruited.The age,gender,and educational background characteristics of the two groups were similar.After functional magnetic resonance imaging(fMRI)scanning,the subjects’spontaneous brain activity was evaluated with the fALFF method.Receiver operating characteristic(ROC)curve analysis was used to classify the data.Further,we used Pearson’s correlation analysis to explore the relationship between fALFF values in specific brain regions and clinical behaviors in patients with HR.RESULTS:The brain areas of the HR group with lower fALFF values than HCs were the right orbital part of the middle frontal gyrus(RO-MFG)and right lingual gyrus.In contrast,the values of fALFFs in the left middle temporal gyrus(MTG),left superior temporal pole(STP),left middle frontal gyrus(MFG),left superior marginal gyrus(SMG),left superior parietal lobule(SPL),and right supplementary motor area(SMA)were higher in the HR group.The results of a t-test showed that the average values of fALFFs were statistically significantly different in the HR group and HC group(P<0.001).The fALFF values of the left middle frontal gyrus in HR patients were positively correlated with anxiety scores(r=0.9232;P<0.0001)and depression scores(r=0.9682;P<0.0001).CONCLUSION:fALFF values in multiple brain regions of HR patients are abnormal,suggesting that these brain regions in HR patients may be dysfunctional,which may help to reveal the pathophysiological mechanisms of HR.

High-resolution magnetic resonance imaging in the diagnosis and management of vertebral artery dissection:A case report

BACKGROUND Vertebral artery dissection(VAD)is a rare but life-threatening condition characterized by tearing of the intimal layer of the vertebral artery,leading to stenosis,occlusion or rupture.The clinical presentation of VAD can be heterogeneous,with common symptoms including headache,dizziness and balance problems.Timely diagnosis and treatment are crucial for favorable outcomes;however,VAD is often missed due to its variable clinical presentation and lack of robust diagnostic guidelines.High-resolution magnetic resonance imaging(HRMRI)has emerged as a reliable diagnostic tool for VAD,providing detailed visualization of vessel wall abnormalities.CASE SUMMARY A young male patient presented with an acute onset of severe headache,vomiting,and seizures,followed by altered consciousness.Imaging studies revealed bilateral VAD,basilar artery thrombosis,multiple brainstem and cerebellar infarcts,and subarachnoid hemorrhage.Digital subtraction angiography(DSA)revealed vertebral artery stenosis but failed to detect the dissection,potentially because intramural thrombosis obscured the VAD.In contrast,HRMRI confirmed the diagnosis by revealing specific signs of dissection.The patient was managed conservatively with antiplatelet therapy and other supportive measures,such as blood pressure control and pain management.After 5 mo of rehabilitation,the patient showed significant improvement in swallowing and limb strength.CONCLUSION HR-MRI can provide precise evidence for the identification of VAD.

Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension:A review

Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-based techniques are standard imaging modalities to non-invasively diagnose CTEPH,however these are limited by radiation exposure,subjective qualitative bias,and lack of cardiac functional assessment.This review aims to assess the methodology,diagnostic accuracy of pulmonary perfusion imaging in the current literature and discuss its advantages,limitations and future research scope.

Is combined functional magnetic resonance imaging and diffusion tensor tractography a useful tool for evaluation of somatosensory dysfunction recovery after intracerebral hemorrhage?

Diffusion tensor tractography allows the sensory fiber course of the medial lemniscus to be visualized. But diffusion tensor tractography for accurate evaluation of the repair of injured somatosensory tracts in stroke patients has been rarely reported. A 55-year-old female patient presented with severe somatosensory dysfunction of the left side caused by a spontaneous intracerebral hemorrhage on the right side. The somatosensory function of the affected side recovered to a nearly normal state at 7 weeks from onset. Functional magnetic resonance imaging revealed that at 3 weeks from onset, there was no cortical activation by touch at each hand; at 7 weeks, the contralateral cortex centered on the primary sensory cortex was found to be activated during touch and passive movements, and activation by passive movements was increased compared with that at 3 weeks. Diffusion tensor tractography revealed that a medial lemniscus on the affected （right） hemisphere was not observed at 3 weeks from onset, however, at 7 weeks, the unaffected （left） hemisphere passed along the medial lemniscus pathway from the pons to the primary sensory cortex. These findings indicate that combined functional magnetic resonance imaging and diffusion tensor tractography would allow more accurate evaluation of the architecture and integrity of somatosensory tracts and is a useful method to investigate the recovery of somatosensory dysfunction in stroke patients.

Effects of iodinated contrast on various magnetic resonance imaging sequences and field strength: Implications for characterization of hemorrhagic transformation in acute stroke therapy

AIM: To characterize the effects of iodinated contrast material(ICM) on magnetic resonance imaging(MRI) comparing different sequences and magnetic fields, with emphasis to similarities/differences with well-known signal characteristics of hemorrhage in the brain. METHODS: Aliquots of iopamidol and iodixanol mixed with normal saline were scanned at 1.5T and 3T. Signal intensity(SI) was measured using similar spin-echo(SE)-T1, SE-T2, gradient-echo(GRE) and fluid-attenuationinversion-recovery(FLAIR) sequences at both magnets. Contrast to noise ratio(CNR)(SI contrast-SI saline/SD noise) for each aliquot were calculated and Kruskall-wallis test and graphic analysis was used to compare different pulse sequences and ICMs. RESULTS: Both ICM showed increased SI on SE-T1 and decreased SI on SE-T2, GRE and FLAIR at both 1.5T and 3T, as the concentration was increased. By CNR measurements, SE-T2 had the greatest conspicuity at 3T with undiluted iopamidol(92.6 ± 0.3, P < 0.00) followed by iodixanol(77.5 ± 0.9, P < 0.00) as compared with other sequences(CNR range: 15-40). While SE-T2 had greatest conspicuity at 1.5T with iopamidol(49.3 ± 1, P < 0.01), SE-T1 showed similar or slightly better conspicuity(20.8 ± 4) than SE-T2 with iodixanol(23 ± 1.7). In all cases, hypo-intensity on GRE was less conspicuous than on SE-T2.CONCLUSION: Iodixanol and iopamidol shorten T1 and T2 relaxation times at both 1.5T and 3T. Hypo-intensity due to shortened T2 relaxation time is significantly more conspicuous than signal changes on T1-WI, FLAIR or GRE. Variations in signal conspicuity according to pulse sequence and to type of ICM are exaggerated at 3T. We postulate T2 hypointensity with less GRE conspicuity differentiates ICM from hemorrhage; given the wellknown GRE hypointensity of hemorrhage. Described signal changes may be relevant in the setting of recent intra-arterial or intravenous ICM administration in translational research and/or human stroke therapy.

Magnetic Resonance Imaging and Histopathological Analysis of Experimental Muscle Injuries in a Rabbit

Objective To investigate the correlation of magnetic resonance imaging （MRI） with histopathologica changes, and to evaluate T2 mapping in assessing muscle trauma in a rabbit model of muscle injury. Methods We divided 35 rabbits into seven groups that each represented a different time point after intramuscular hemorrhage and muscle injury. Hemorrhage was created by injecting autologous blood into the left legs, and muscle injury was created by scalpel incision of the biceps femoris of the right legs. At different time points, the rabbits underwent Tl-weighted imaging and T2-weighted imaging （TzWl and T2Wl） and T2 mapping. T2 relaxation times were measured, and the corresponding samples were evaluated for pathological changes. Results After 2 h, the intramuscular hemorrhage model demonstrated an increased signal intensity on both TlWl and T2Wl. Histological examination showed erythrocytes within the muscle bundle. On days 1 and 3, the MRI signals were decreased, and there were no significant changes after day 7. From 2 h to 3 days, the muscle-injury model showed a high signal on both TzWl and T2Wl. Corresponding pathological changes included rupture and edema of muscle fibers, and inflammation. The abnormal signals were reduced on day 7. After day 14, the T2Wl intensity remained high. TlWl showed no abnormal changes, but some models showed a high signal, representing fresh bleeding and fatty tissue. T2 relaxation times were significantly different between the central and marginal regions, and between the marginal and normal regions. Conclusion MRI clearly demonstrates intramuscular hemorrhage and muscle injury, which correlate well with histopathological changes. Tz mapping is useful in assessing the extent of injury.

Validation of hyperintense middle cerebral artery sign in acute ischemic stroke Comparison between magnetic resonance imaging and angiography

We performed a retrospective analysis of non-contrast computed tomography （CT） scans, immediately subsequent magnetic resonance imaging （MRI）, and cerebral angiography data from 30 consecutive patients with acute ischemic stroke within 6 hours after symptom onset. Results showed that eleven patients developed subsequent hemorrhagic transformation at follow-up. A hyperintense middle cerebral artery sign on MRI was found in six hemorrhagic patients, all of who had acute thrombosis formation on magnetic resonance angiography and digital subtraction angiography. No patients in the non-hemorrhagic group had hyperintense middle cerebral artery sign on MRI. The sensitivity, specificity, and positive predictive values of the hyperintense middle cerebral artery sign on MRI T1-weighted image for subsequent hemorrhagic transformation were 54.5%, 100%, and 100% respectively. Hyperdense middle cerebral artery sign on non-contrast CT was observed in nine patients, five of who developed hemorrhagic transformation. These data suggest that hyperintense middle cerebral artery sign on MRI T1-weighted image is a highly specific and moderately sensitive indicator of subsequent hemorrhagic transformation in patients after acute ischemic stroke, and its specificity is superior to CT.

Use of 3-D magnetic resonance electrical impedance tomography in detecting human cerebral stroke: a simulation study

We have developed a new three dimensional (3-D) conductivity imaging approach and have used it to detect human brain conductivity changes corresponding to acute cerebral stroke. The proposed Magnetic Resonance Electrical Impedance Tomography (MREIT) approach is based on the J-Substitution algorithm and is expanded to imaging 3-D subject conductivity distribution changes. Computer simulation studies have been conducted to evaluate the present MREIT imaging approach. Simulations of both types of cerebral stroke, hemorrhagic stroke and ischemic stroke, were performed on a four-sphere head model. Simulation results showed that the correlation coefficient (CC) and relative error (RE) between target and estimated conductivity distributions were 0.9245±0.0068 and 8.9997%±0.0084%, for hemorrhagic stroke, and 0.6748±0.0197 and 8.8986%±0.0089%, for ischemic stroke, when the SNR (signal-to-noise radio) of added GWN (Gaussian White Noise) was 40. The convergence characteristic was also evaluated according to the changes of CC and RE with different iteration numbers. The CC increases and RE decreases monotonously with the increasing number of iterations. The present simulation results show the feasibility of the proposed 3-D MREIT approach in hemorrhagic and ischemic stroke detection and suggest that the method may become a useful alternative in clinical diagnosis of acute cerebral stroke in humans.

Novel contributions of multimodality imaging in hypertension:A narrative review

Hypertension is currently one of the most prevalent il nesses worldwide,and is the second most common cause of heart failure,only behind ischemic cardiomyopathy.The development of novel multimodality imaging techniques in recent years has broadened the diagnostic methods,risk stratification and monitoring of treatment of cardiovascular diseases available for clinicians.Cardiovascular magnetic resonance(CMR) has a great capacity to evaluate cardiac dimensions and ventricular function,is extremely useful in ruling-out ischemic cardiomyopathy,the evaluation of the vascular system,in making the differential diagnosis for resistant hypertension and risk stratification for hypertensive cardiomyopathy and constitutes today,the method of choice to evaluate left ventricular systolic function.Computed tomography(CT) is the method of choice for the evaluation of vascular anatomy,including coronary arteries,and is also able to provide both functional and structural information.Finally,nuclear cardiology studies have been traditionally used to evaluate myocardial ischemia,along with offering the capacity to evaluate ventricular,endothelial and cardiac innervation function;information that is key in directing the treatment of the patient.In this narrative review,the most recent contributions of multimodality imaging to the patient with hypertension(CMR,CT and nuclear cardiology) will be reviewed.

Correlation between muscular strength and basal nuclei ischemic/hemorrhagic stroke-induced corticospinal tract injury,as detected by diffusion tensor imaging and tractography

BACKGROUND： Conventional neuroimaging diagnosis does not assist with the monitoring or evaluation of basal nuclei ischemic and hemorrhagic stroke, or motor functional recovery. Magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography have all been used to observe features of cerebral white matter fibrous structures. In addition, diffusion tensor tractography is the only non-invasive imaging method to display the corticospinal tract in vivo. OBJECTIVE： To evaluate the impairment degree of corticospinal tract induced by basal nuclei ischemic and hemorrhagic stroke through the use of magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography, and to analyze the correlation to muscular strength. DESIGN, TIME AND SETTING： A retrospective case analysis was performed at the Department of Medical Imaging, Neurology and Neurosurgery, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA between November 2002 and June 2008. PARTICIPANTS： A total of 15 patients with acute or subacute cerebral ischemic stroke and nine with hemorrhagic stroke in the basal nuclei were selected. METHODS： Magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography results and data were analyzed. Fractional anisotropy and directionally encoded color maps were obtained. Three-dimensional tractography of bilateral corticospinal tract was created, and corticospinal tract integrity was graded. Fractional anisotropy of infarct region and corresponding contralateral normal regions were measured, and hematoma volume in hemorrhagic stroke patients was determined. Hand motor function ability was evaluated using Brunstorm criteria. MAIN OUTCOME MEASURES： Fractional anisotropy of infarct region and corresponding contralateral normal regions; hematoma volume in hemorrhagic stroke patients; correlation between muscular strength and corticospinal tract impairment degree in ischemic stroke and hemorrhagic stroke patients before and after treatment. RESULTS： In ischemic stroke patients, the fractional anisotropy value was significantly lower in the infarct area of white matter than in the normal hemisphere （P 〈 0.01）. The impairment degree of corticospinal tract negatively correlated with muscular strength of the corresponding hand （r = -0.97 P 〈 0.01）. The hematoma volume of hemorrhagic stroke patients significantly negatively correlated with Spearman test results for muscular strength of the corresponding hand （r = -0.88, P 〈 0.01）. CONCLUSION： Corticospinal tract impairment severity negatively correlated with muscular strength and motor functional recovery, which suggested that diffusion tensor imaging and diffusion tensor tractography could be used to evaluate corticospinal tract motor function.

Imaging of hemorrhagic primary central nervous system lymphoma: A case report

BACKGROUND A primary central nervous system lymphoma(PCNSL)presenting with massive hemorrhage is a rare occurrence that is difficult to distinguish from a high-grade glioblastoma.Comprehensive descriptions of the imaging characteristics of such tumors have not yet been reported.Herein,we reported a case of a PCNSL with massive hemorrhage by presenting the imaging features of computed tomography(CT)imaging and structural and perfusion magnetic resonance imaging(MRI).CASE SUMMARY A 48-year-old man presented with headache lasting for 10 d.CT of the brain showed a round,heterogeneous,high-density lesion with surrounding edema in the right temporal lobe.For further diagnosis,a series of MRI examinations of the brain were subsequently performed,and a hemorrhagic lesion with ring-like enhancement was determined.The whole lesion was relatively hypoperfused on arterial spin labeling images.Surgical resection of the lesion and histopathological examination confirmed that the lesion was a diffuse large B-cell lymphoma with massive hemorrhage.CONCLUSION PCNSLs with hemorrhage occur very rarely,and structural and perfusion MRI examinations are requested exceedingly rarely.This case provided insight into some characteristics of a hemorrhagic lymphoma on CT and MRI examinations.Perfusion MRI examination may be useful for the differential diagnosis of PCNSLs and other brain tumors.

A Comparative Study of Automated Segmentation Methods for Use in a Microwave Tomography System for Imaging Intracerebral Hemorrhage in Stroke Patients

Microwave technology offers the possibility for pre-hospital stroke detection as we have previously demonstrated using non-imaging diagnostics. The focus in this paper is on image-based diagnostics wherein the technical and computational complexities of image reconstruction are a challenge for clinical realization. Herein we investigate whether information about a patient’s brain anatomy obtained prior to a stroke event can be used to facilitate image-based stroke diagnostics. A priori information can be obtained by segmenting the patient’s head tissues from magnetic resonance images. Expert manual segmentation is presently the gold standard, but it is laborious and subjective. A fully automatic method is thus desirable. This paper presents an evaluation of several such methods using both synthetic magnetic resonance imaging (MRI) data and real data from four healthy subjects. The segmentation was performed on the full 3D MRI data, whereas the electromagnetic evaluation was performed using a 2D slice. The methods were evaluated in terms of: i) tissue classification accuracy over all tissues with respect to ground truth, ii) the accuracy of the simulated electromagnetic wave propagation through the head, and iii) the accuracy of the image reconstruction of the hemorrhage. The segmentation accuracy was measured in terms of the degree of overlap (Dice score) with the ground truth. The electromagnetic simulation accuracy was measured in terms of signal deviation relative to the simulation based on the ground truth. Finally, the image reconstruction accuracy was measured in terms of the Dice score, relative error of dielectric properties, and visual comparison between the true and reconstructed intracerebral hemorrhage. The results show that accurate segmentation of tissues (Dice score = 0.97) from the MRI data can lead to accurate image reconstruction (relative error = 0.24) for the intracerebral hemorrhage in the subject’s brain. They also suggest that accurate automated segmentation can be used as a surrogate for manual segmentation and can facilitate the rapid diagnosis of intracerebral hemorrhage in stroke patients using a microwave imaging system.

Magnetic resonance susceptibility weighted imaging in detecting intracranial calcification and hemorrhage

Background Computed tomography （CT） is better than routine magnetic resonance imaging （MRI） in detecting intracranial calcification. This study aimed to assess the value of MR susceptibility weighted imaging （SWI） in the detection and differentiation of intracranial calcification and hemorrhage. Methods Enrolled in this study were 35 patients including 13 cases of calcification demonstrated by CT and 22 cases of intracerebral hemorrhage. MR sequences used in all the subjects included axial T1WI, T2WI and SWI. The phase shift （PS） of calcification and hemorrhage on SWI was calculated and their signal features on corrected phase images were compared. The sensitivity of T1WI, T2WI and SWI in detecting intracranial calcification and hemorrhage was analyzed statistically. Results The detection rate of SWI for cranial calcification was 98.2%, significantly higher than that of T1WI and T2WI. It was not significantly different from that of CT （P 〉0.05）. There were 49 hemorrhagic lesions at different stages detected on SWI, 30 on T2WI and 18 on T1WI. The average PS of calcification and hemorrhage was ＋0.734±0.073 and -0.112±0.032 respectively （P 〈0.05）. The PS of calcification was positive and presented as a high signal or the mixed signal dominated by a high signal on the corrected phase images, whereas the PS of hemorrhage was negative and presented as a low signal or the mixed signal dominated by a low signal.Conclusions SWI can accurately demonstrate intracranial calcification, not dependant on CT. Being more sensitive than routine MRI in detecting micro-hemorrhage, SWI may play an important role in differentiating cerebral diseases associated with calcification or hemorrhage.

Study of clinical features of amyloid angiopathy hemorrhage and hypertensive intracerebral hemorrhage

Objective: The purpose of this study was to differentiate between cerebral amyloid angiopathy (CAA) and hypertension (HTN) based on hemorrhage pattern interpretation. Methods: From June 1994 to Oct., 2000, 83 patients admitted to our service with acute intracerebral hemorrhage (ICH) were investigated retrospectively; 41 patients with his-tologically proven diagnosis of cerebral amyloid angiography and 42 patients with clear history of hypertension were investigated. Results: Patients with a CAA-related ICH were significantly older than patients with a HTN-related ICH (74.0 years vs 66.5 years, P<0.05). There was a significantly higher number of hematomas> ml in CAA (85.3%) when compared with HTN (59.5%). No basal ganglional hemorrhage was seen in CAA, but in 40.5% in HTN. In CAA-related ICH, su-barachnoid hemorrhage (SAH) was seen in 26 patients (63.4%) compared to only 11 patients (26.2%) in HTN-related ICH. Intraventricular hemorrhage was seen in 24.4% in CAA, and in 26.2% in HTN. Typical features of CAA-related ICH included lobar distribution affecting mainly the lobar superficial areas, lobulated appearance, rupture into the subarachnoid space, and secondary IVH from the lobar hemorrhage. More specifically, multiplicity of hemorrhage, bilaterality, and repeated episodes also strongly suggest the diagnosis of CAA. Multiple hemorrhages, defined as 2 or more separate he-matomas in multiple lobes, accounted for 17.1% in CAA-related ICH. Conclusion: There are certain features in CAA on CT and MRI and in clinical settings. To some extent, these features may contribute to distinguishing CAA from HTN related ICH.

Beneficial long term effect of a phosphodiesterase-5-inhibitor in cirrhotic portal hypertension:A case report with 8 years follow-up

Non-selective beta-blockers are the mainstay of medical therapy for portal hypertension in liver cirrhosis. Inhibitors of phosphodiesterase-5(PDE-5-inhibitors) reduce portal pressure in the acute setting by > 10% which may suggest a long-term beneficial effect. Currently, there is no available data on long-term treatment of portal hypertension with PDE-5-inhibitors. This case of a patient with liver cirrhosis secondary to autoimmune liver disease with episodes of bleeding from esophageal varices is the first documented case in which a treatment with a PDE-5-inhibitor for eight years was monitored. In the acute setting, the PDE-5-inhibitor Vardenafil lowered portal pressure by 13%. The portal blood flow increased by 28% based onDoppler sonography and by 16% using MRI technique. As maintenance medication the PDE-5-inhibitor Tadalafil was used for eight consecutive years with comparable effects on portal pressure and portal blood flow. There were no recurrence of bleeding and no formation of new varices. Influencing the NO-pathway by the use of PDE-5 inhibitors may have long-term beneficial effects in compensated cirrhosis.

Portal hypertension in a patient with biliary hamartomas: A case report

BACKGROUND Biliary hamartomas(BH)are a rare benign disease caused by malformation of the intrahepatic bile ducts.BH are occasionally diagnosed,but often lack obvious clinical symptoms.They are usually diagnosed by biopsy and imaging tests in clinical practice.Few studies have reported the association of BH with portal hypertension.CASE SUMMARY A 40-year-old man was repeatedly admitted to our hospital due to hematochezia.The source of bleeding was considered to be gastroesophageal varices and portal hypertensive gastropathy by endoscopy.He had no history of hepatitis virus infection,alcohol abuse,drug-induced liver injury,or autoimmune liver disease.He underwent magnetic resonance imaging,which showed rounded,irregular,low-signal-T1 and high-signal-T2 lesions diffusely distributed on the liver,that were not communicated with the biliary system on magnetic resonance cholangiopancreatography.According to the imaging examination,the patient was considered to have a diagnosis of BH with portal hypertension.CONCLUSION Based on the present case report,BH may be a potential etiology of portal hypertension.

Automated Brain Hemorrhage Classification and Volume Analysis

Brain hemorrhage is a serious and life-threatening condition. It cancause permanent and lifelong disability even when it is not fatal. The wordhemorrhage denotes leakage of blood within the brain and this leakage ofblood from capillaries causes stroke and adequate supply of oxygen to thebrain is hindered. Modern imaging methods such as computed tomography(CT) and magnetic resonance imaging (MRI) are employed to get an idearegarding the extent of the damage. An early diagnosis and treatment can savelives and limit the adverse effects of a brain hemorrhage. In this case, a deepneural network (DNN) is an effective choice for the early identification andclassification of brain hemorrhage for the timely recovery and treatment of anaffected person. In this paper, the proposed research work is divided into twonovel approaches, where, one for the classification and the other for volumecalculation of brain hemorrhage. Two different datasets are used for twodifferent techniques classification and volume. A novel algorithm is proposedto calculate the volume of hemorrhage using CT scan images. In the firstapproach, the ‘RSNA’ dataset is used to classify the brain hemorrhage typesusing transfer learning and achieved an accuracy of 93.77%. Furthermore,in the second approach, a novel algorithm has been proposed to calculate thevolume of brain hemorrhage and achieved tremendous results as 1035.91mm3and 9.25 cm3, using the PhysioNet CT scan tomography dataset.

Pancreatic cavernous hemangioma complicated with chronic intracapsular spontaneous hemorrhage:A case report and review of literature

BACKGROUND Pancreatic cavernous hemangioma(pCH)is a rare type of benign vascular tumor.Making the right diagnosis is challenging due to low clinical suspicion and the lack of existing cross-sectional imaging tools to distinguish it from other pancreatic lesions.CASE SUMMARY We describe a male patient,age 18,who presented with a pCH.Computed tomography,magnetic resonance imaging,and ultrasound showed cystic space in the tail of the pancreas.A dark spot sign on the T2 weighted image sequence was observed.Clinically,a mucinous cystic neoplasm with hemorrhage was suspected preoperatively by combining imaging,and the operative indication was clear.The patient underwent a distal pancreatic tumor resection under laparoscopic control.Immunohistochemical staining for CD31 and CD34 was positive;D2-40 was positive in interstitial lymphatic vessels and negative in vascular epithelial cells;and calcium-binding protein was negative.The results support the diagnosis of pCH combined with chronic intracapsular spontaneous hemorrhage.No complications or recurrences were observed during the follow-up period.CONCLUSION Chronic spontaneous hemorrhage may occur in pCH,which may greatly influence the accuracy of diagnosis using imaging modalities.Surgical resection for uncertain pCH seems reasonable with a good outcome.

CT及MRI预测急性缺血性脑梗死出血性转化的价值研究进展

脑梗死是全球排名第二大致死原因,在中国已成为第一大致残及死亡原因。急性缺血性脑梗死(acute ischemic stroke,AIS)则是最常见的脑梗死类型,约占全部脑梗死的80%。出血性转化(hemorrhagic transformation,HT)是AIS患者的自然转归过程之一,也是静脉溶栓治疗(intravenous thrombolysis,IVT)或血管内取栓治疗等治疗后最严重的并发症,给患者及其家庭和社会都带来沉重的负担。精准预测、评估AIS的HT具有重要临床意义。近年影像学研究集中于CT和MRI评估HT的价值。CT平扫诊断HT价值有限,AIS治疗前,阿尔伯塔脑梗死计划早期诊断评分≤7分与HT发生相关(P=0.033),高密度大脑中动脉征是发生HT的独立危险因素(OR=10.334);AIS取栓治疗后24 h复查双能CT,预测2~7 d内发生HT风险的效能较高(灵敏度82.5%、特异度100%)。CT血管造影中,血栓负荷高的患者HT发生概率上升(OR=1.28);侧支循环良好的AIS患者HT发生率低。CT灌注成像参数包括表面渗透性、脑血容量、Tmax等,均有较好的HT预测价值。MRI平扫中,FLAIR上高信号可预测HT的发生;MRI弥散加权成像,高信号区域体积可预测HT(ROC曲线下面积0.78);MRI磁敏感率加权成像,刷状征、微出血灶提示HT的发生;MRI增强T1加权成像,脑实质强化与HT发生显著相关(P<0.05);MRI灌注加权成像中,梗死区脑血容量降低可预测HT。此外,CT及MRI图像后处理系统RAPID提升了评估HT的效能。建议根据各急救中心的硬件及当地医疗情况,设置个性化的影像学检测方式及流程,预测及管理HT。

影像学在肾血管性高血压评估中的进展

肾血管性高血压是继发性高血压最常见的原因之一,是指由肾动脉狭窄引起的高血压。绝大多数肾动脉狭窄是由动脉粥样硬化或纤维肌肉发育不良引起。随着影像学检查技术的快速发展,该疾病的早期检出率不断升高。尤其是各种无创性影像学检查技术在肾动脉狭窄的诊疗过程中起到了至关重要的作用,可早期识别肾动脉、肾脏结构及功能的异常,帮助患者实现早期诊断及获得早期充分治疗。现就影像学在肾动脉狭窄评估中的应用进展进行综述。