Application of three-dimensional fast gradient echo sequence in observation of craniocervical junctional ligament / 中南大学学报(医学版)

OBJECTIVES@#To explore the value of three-dimensional fast gradient echo sequence (3D-GRE) in observation of the craniocervical junctional ligament.@*METHODS@#A total of 21 healthy volunteers underwent 3D-GRE imaging. The imaging data was imported into the post-processing workstation. The structures of the ligaments in the craniocervical junctional area were observed and evaluated by multiplanar reconstruction technique.@*RESULTS@#The features of ligaments in the craniocervical junction were shown clearly for all the 21 cases of volunteers. The scan time was 267-294 s. After the treatment with the three-dimensional reconstruction technique, the signal characteristics and the running structure of the transverse ligament, the alar ligament, the serrated ligament and the lamina could be effectively displayed.@*CONCLUSIONS@#The 3D-GRE can evaluate the three-dimensional data of craniocervical junctional ligament in a short period of time. Post-processing reconstruction technique can clearly evaluate the structure characteristics of each ligament, which can lay a foundation for further application in craniocerebral trauma patients.

Transfusional Iron Overload and Choroid Plexus Hemosiderosis in a Pediatric Patient: Brain Magnetic Resonance Imaging Findings

Hemosiderosis is characterized by the deposition of excess iron in body tissues. The choroid plexus is an important part of the central nervous system that can be the primary site of iron overload. T2*-weighted gradient echo (GRE) sequence provides high sensitivity for demonstrating cerebral microhemorrhagic foci and iron deposition. In the present study, we describe the case of a 15-year-old boy with acute lymphoblastic leukemia, in whom repeated transfusion led to iron accumulation in the brain. GRE sequence effectively demonstrated hemosiderin deposition in the choroid plexus.

Role of diffusion weighted MRI in characterization of renal diseases

Background: MRI has the unique ability to show both structure and function objectively without any radiation exposure to the patient. Apparent diffusion coefficient (ADC) is a quantitative parameter that combines the effects of capillary perfusion and water diffusion. Renal parameters have shown inverse relationship with the ADC values in these studies. So, ADC values have a potential to serve as a marker of renal function. The aim of the present endeavor was to study the role of DW MRI in characterization of renal function and to find out the clinical use of DW MRI in renal diseases; and establish the relationship between renal function assessed by eGFR and that by DW MRI calculated in terms of ADC values in various renal diseasesMethods: Total 30 patients were included in the study. The study was carried out in department of radiodiagnosis at Dr. RPMGC Kangra. 1.5 Tesla MRI machine was used. The ADC value was calculated at upper, mid and lower pole of each kidney and the mean was taken. Then the mean of right and left kidneys was taken to calculate the mean ADC of the patient.Results: Serum creatinine in present study ranged from 0.67 to 13.9mg/dl, with mean value of 7.28mg/d. Serum urea ranged from 22 to 293mg/dl with the mean of 119.6mg/dl. There was significant inverse correlation occurred between ADC values and serum urea (r=-0.43, p=0.02). There was significant inverse correlation between ADC values and serum creatinine (p=0.01) and a positive correlation between eGFR and ADC values (r=0.14, p=0.47).Conclusions: ADC values consistently decreased with increasing stage of renal failure, so these can be used as an indirect maker of renal function. Authors conclude that lower would be the ADC value more advanced would be the stage of renal failure. DW MRI can also be detect early stages of renal failure even when the serum maker are within normal range.

Susceptibility weighted imaging: current clinical applications and development prospects / 中华神经科杂志

As a routine scanning method of magnetic resonance imaging nowadays , susceptibility weighted imaging provides very important diagnostic information for daily medical treatment in clinical departments such as neurology , neurosurgery, and emergency departments.With the continuous improvement and upgrading , the scope of its clinical application has been further expanded , such as analysis of quantitative susceptibility mapping , perinatal fetal monitoring and neonatal disease diagnosis , guiding clinical therapy strategies and so on.Owing to the great potential and scientific value of this technology , its future development prospects will be new sequence improvement , multiple body parts'application, functional image research, etc.

Functional magnetic resonance imaging in the accurate diagnosis of gliomas / 实用肿瘤学杂志

Objective The aim of this study was to evaluate the glioma using the variety of functional magnetic resonance imaging( fMRI) ,and to perform a more accurate preoperative diagnosis of gliomas. Methods Thirty - five patients with gliomas confirmed by pathology were examined by magnetic resonance imaging (MRI)and functional MRI. Rapid diffusion coefficient(D?),Slow diffusion coefficient(D),perfusion fraction ( f) and distribution diffusion coefficient ( DDC ) in the intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) were analyzed statistically. Results The mean values of D?,D,f and DDC in the IVIM se-quence of the patients with high-grade of gliomas were statistically significant when compared to the IVIM values of the contralateral normal brain tissues(P<0. 05). Conclusion A variety of magnetic resonance functional im-aging sequences are used to analyze gliomas,which can avoid tumor heterogeneity and improve the recognition a-bility and accuracy of magnetic resonance imaging in high grade gliomas.

Comparison of T2 FLAIR and GRE-T2* WI in detection of traumatic extra-axial hemorrhage / 实用放射学杂志

Objective To explore the value of fluid-attenuated inversion recovery (FLAIR)sequence and gradient echo T2 ?weighted image (GRE-T2 ? WI)in diagnosis of acute traumatic extra-axial hemorrhage.Methods 50 patients who were diagnosed as acute traumatic extra-axial hemorrhage by plain CT underwent FLAIR and GRE-T2 ? WI in acute stage.The diagnosis consistency (Kappa ),detection rate of subarachnoid hemorrhage(SAH),epidural hemorrhage(EDH)and subdural hemorrhage(SDH)were compared.The detection rates of SAH in 8 locations among FLAIR,GRE-T2 ? WI and combination of two sequences were analyzed by Chi-square test.Results 48 patients were enrolled in the study.The diagnosis consistency of SAH between FLAIR and GRE-T2 ? WI was high (k =1.0).The detection rate of SAH was 100% for both FLAIR and GRE-T2 ? WI.Comparing with GRE-T2 ? WI and combi-nation of two sequences,FLAIR tended to misdiagnose SAH in perimesencephalic cistern (P <0.05).The diagnosis consistency of EDH between FLAIR and GRE-T2 ? WI was high (k =1.0).3 patients with EDH were all detected by FLAIR and GRE-T2 ? WI. The diagnosis consistency of SDH between FLAIR and GRE-T2 ? WI was high (k =0.943).The detection rate of 12 patients with SDH was 100% in FLAIR,and 1 patient with SDH was missed by GRE-T2 ? WI.Conclusion The detection rate of acute traumatic extra-axial hemorrhage is high for both FLAIR and GRE-T2 ? WI.Combination of two sequences can improve the accuracy of acute traumatic extra-axial hemorrhage in clinic.

Cerebrotendinous Xanthomatosis with Low Signal on Gradient Echo Magnetic Resonance Imaging

No abstract available.

Cerebrotendinous Xanthomatosis with Low Signal on Gradient Echo Magnetic Resonance Imaging

No abstract available.

Cavernomatosis cerebral múltiple: primer reporte de caso en Perú / Multiple cerebral cavernous: first case report in Peru

La cavernomatosis cerebral (CC), única o múltiple, es la presencia de conductos vasculares distendidos, angiográficamente ocultos, por lo cual clásicamente eran hallazgos incidentales intraoperatorios o en autopsias. Actualmente la resonancia magnética (RM) cerebral, permite identificar éstas lesiones en un mayor número de pacientes. Las manifestaciones clínicas son hemorragias intracerebrales, crisis epilépticas y cefalea. Se reporta el caso de un varón de 55 años, sin antecedentes de importancia que ingresó por presentar cefalea y crisis de arresto del habla. El examen físico fue normal. Estudios tomográficos previos mostraron una lesión hemorrágica única, al realizarse una RM cerebral con protocolo T2-eco gradiente se evidencia múltiples imágenes compatibles con CC múltiple. Es el primer reporte de CC múltiple, entidad poco diagnosticada, que se debe sospechar en pacientes sin antecedentes de riesgo vascular que debutan con hemorragias intracerebrales, crisis epilépticas y/o cefaleas; constituyendo la RM cerebral en protocolo T2-eco gradiente, el estudio indicado para el diagnóstico.

Cerebral cavernomatosis (CC), single or multiple, is the presence of distended vascular channels, angiographically occult, for that, they are classically incidental intraoperative findings at autopsy. Currently the magnetic resonance imaging (MRI) let us identify these lesions in a larger number of patients. Clinical manifestations are intracerebral hemorrhages, seizures and headache. A male, 55, no history of significance is reported; he was admitted for headache and some months later presents speech arrest crisis. On physical examination, nothing unusual. Previous tomographic studies showed a hemorrhagic lesion, when the brain MRI with T2-eco gradient protocol was performed, multiple images observed, were compatible with multiple CC. This is the first report of multiple CC, unfrequent entity that should be suspected in patients with no history of vascular risk who present intracerebral hemorrhage, seizure and / or headache; being the brain MRI, the study indicated for diagnosis.

Valoración no invasiva de la sobrecarga hepática de hierro en pacientes con hemocromatosis / Noninvasive assessment of hepatic iron overload in patients with hemochromatosis

Nuestro objetivo es analizar el metabolismo y la fisiopatología del depósito de hierro, describir la utilidad de la resonancia magnética (RM) con el empleo de secuencias específicas en la estimación de la sobrecarga hepática de hierro y evaluar las diferentes patologías que la generan en el abdomen, señalando también sus formas de presentación en la RM. La sobrecarga de hierro en el hígado puede ser consecuencia de un trastorno genético (hemocromatosisprimaria) o estar relacionada con múltiples transfusiones o enfermedades crónicas, como aumento de la absorción, mielodisplasia, talasemia, etc. (hemocromatosis secundaria). La RM es un método no invasivo que permite detectar la sobrecarga de hierro y monitorear el tratamiento luego del diagnóstico, evitando la repetición de biopsias. Esto se debe a las propiedades paramagnéticas del hierro, cuya acumulación en los tejidos provoca distorsión local en los campos magnéticos, con disminución de la señal en los órganos afectados de forma proporciona la la cantidad de hierro depositado. La RM convencional con secuencias en fase y fuera de fase detecta el depósito de hierro en el hígado, bazo y páncreas, aunque las formas leves pueden pasar inadvertidas si no se utilizan secuencias más sensibles, como las de eco de gradiente. Estas, según la técnica de Gandon et al., permiten estimar cuantitativamente la severidad. El depósito de hierro puede tener un patrón retículo-endotelial (secundario a múltiples transfusiones con depósito en hígado, bazo y médula ósea sin daño tisular), parenquimatoso (hígado y páncreas) o mixto. La RM es fundamental en el diagnóstico de la hemocromatosis, especialmente en la fase subclínica.Contribuye a definir la severidad de la sobrecarga de hierro hepático y a valorar la respuesta al tratamiento, evitando procedimientos invasivos.

Our purpose is to analyze the metabolism and pathophysiology of iron deposition, to describe the usefulness of magnetic resonance imaging (MRI) in the estimation of hepatic iron overload using specific sequences, and to review the different pathologies leading to iron overload of the abdominal organs and its presentation in MRI.Iron overload in the liver may be due to a genetic condition (primary hemo chromatosis), or due to multiple blood transfusions and chronic diseases like increased absorption, myelodysplasia, thalassemia, etc. (secondary hemochromatosis).MRI is a noninvasive method to detect the presence of iron overload and to monitor treatment after diagnosis, avoiding repeated biopsies. This is due to the paramagnetic properties of iron accumulation in the tissues causing local distortion in the magnetic field. This phenomena is seen as a reduction of the MRI signal in the affected organs, being directly proportional to the amount of iron deposited.The conventional in phase and out of phase MRI sequences can show iron deposition in liver, spleen and pancreas, although milder forms may go undetected if more sensitive sequences, like gradient echo sequence, are not used, according to the technique proposed by Gandon et al., which can estimate quantitatively the severity of iron deposition.Iron deposition can show a reticuloendothelial type pattern (secondary to multiple transfusions where iron deposits in the liver, spleen and bone marrow without tissue damage), a parenchymal pattern (involving the liver and pancreas) and a mixed pattern.MRI has a fundamental role in the diagnosis of hemochromatosis, especially in subclinical phase. It helps to stratify the severity of hepatic iron overload and assess response to treatment, avoiding invasive procedures.

Cerebral Microbleeds: Their Associated Factors, Radiologic Findings, and Clinical Implications / 대한뇌졸중학회지

Cerebral microbleeds (CMBs) are tiny, round dark-signal lesions that are most often detected on gradient-echo MR images. CMBs consist of extravasations of blood components through fragile microvascular walls characterized by lipohyalinosis and surrounding macrophages. The prevalence of CMBs in elderly subjects with no history of cerebrovascular disease is around 5%, but is much higher in patients with ischemic or hemorrhagic stroke. Development of CMBs is closely related to various vascular risk factors; in particular, lobar CMBs are thought to be associated with cerebral amyloid angiopathy. The presence of CMBs has been hypothesized to reflect cerebral-hemorrhage-prone status in patients with hypertension or amyloid microangiopathy. Stroke survivors with CMBs have been consistently found to have an elevated risk of subsequent hemorrhagic stroke or an antithrombotic-related hemorrhagic complication, although studies have failed to establish a link between CMBs and hemorrhagic transformation after thrombolytic treatment. A large prospective study is required to clarify the clinical significance of CMBs and their utility in a decision-making index.

Two-dimensional Multiple-echo Recalled Gradient Echo Sequence at Flexion Position in the Diagnosis of Hirayama Disease / 中国医学影像学杂志

Purpose To evaluate the diagnostic value of two-dimensional multiple-echo recalled gradient echo (2D MERGE) with flexural position in the hirayama disease. Materials and Methods Conventional MRI and axial MERGE images (7 cases) were analyzed and the anteroposterior diameter was measured at C6 vertebral body, and the structure of spinal, extramedullary and subdural space and extradural space were compared. Results The anteroposterior diameter was (5.7±0.6) cm and (4.7±0.5) cm in the neutral position and flexural position (t=-2.95, P<0.05). The“butterfly”shape of spinal grey matter could not be detected in the 4 cases on MERGE with flexural position, which could not demonstrated on the conventional MR images. 2D MERGE was not sensitive for the CSF flow artefacts and the contrast between spinal and surrounding structures was improved. However, the vascular images could not displayed on 2D MERGE images. Conclusion 2D MERGE sequence is better than T1WI and T2WI on sagittal view and T2WI on axial view in the pathological changes of hirayama disease except flow-empty vein sign, thus it has an important role in diagnosing hirayama disease.

A newly Developed Hyperintensity Within a Posterior Cerebral Artery Susceptibility Vessel Sign in T2*-Weighted Gradient-Echo Imaging: a Case Report and Correlation with Magnetic Resonance Angiography and Black-Blood Imaging

The susceptibility vessel sign (SVS) on T2*-weighted gradient-echo imaging (T2*-GRE) is useful for detecting intra-arterial clots and monitoring the response to thrombolysis. SVS-GRE was observed in a 52-year-old man with acute occlusion of the posterior cerebral artery (PCA) before and after failed intra-arterial thrombolysis. One-week follow-up T2*-GRE revealed a hyperintensity within the SVS-GRE in the affected PCA. The right PCA remained occluded on time-of-flight (TOF) magnetic resonance angiography (MRA), but its P2 segment exhibited luminal patency on contrast-enhanced (CE) MRA. Black-blood MR imaging using a T1-weighted turbo-spin echo sequence revealed narrowing of the arterial lumen and thickening of the wall due to an atherosclerotic plaque. The observations from TOF-MRA, CE-MRA, and black-blood MR imaging suggest that a newly developed hyperintensity within the SVS-GRE seems to be associated with slow flow through a severe atherosclerotic stenosis or near-occlusion.

Acute Onset Of Nonketotic Hyperglycemic Hemichorea Associated With Putaminal Hypointensity On Gradient Echo Magnetic Resonance Image

No abstract available.

Magnetization transfer contrast gradient echo T2WI sequence in the diagnosis of bone contusion of knee joint / 中国医学影像技术

Objective To assess the diagnostic value of magnetization transfer contrast (MTC) gradient echo (GRE) T2WI sequence in bone injury of knee joint. Methods MRI data of 56 patients with knee injury were analyzed retrospectively. All patients underwent SE sequence (sagittal T1WI, T2WI) and sagittal MTC-GRE T2WI sequence. The size, signal intensity and margin of bone contusion with different MRI sequence were analyzed and compared. Results Among 56 patients, 43 and 45 cases were demonstrated on SE T1WI and T2WI, respectively; 50 cases were displayed on MTC-GRE T2WI sequence. The size, border of bone contusions and sensitivity displayed on MTC-GRE T2WI sequence were statistically higher than those on SE sequence (P<0.05). Conclusion MTC-GRE T2WI sequence has great diagnostic value in contusion of knee joint, which is superior to FSE sequence.

Magnetic Resonance Imaging of Intracranial Hemorrhage / 国际脑血管病杂志

Traditional sequences of magnetic resonance imaging (MRI) such as T1-weighed imaging, T2-weighed imaging, and fluid-attenuated inversion recovery (FLAIR) imaging can sensitively detect the subacute and chronic intracranial hemorrhage; gradient echo sequence can detect various stages of intracranial hemorrhage, but there is no correlation between the signal intensity of the hematoma and the time of the presence of hematoma. Diffusion-weighted imaging and apparent diffusion coefficient may provide more information about the center and surrounding areas of hematoma, as well as the hemorrhagic tendency after infarction.

The Relationship of Matrix Metalloproteinase-9 and Microbleeds on T2*-Weighted Gradient-Echo MRI in Acute Lacunar Infarction

BACKGROUND: Hypointense cerebral lesions on T2*-weighted gradient-echo MRI (GRE) have been known to be related with microbleeds or advanced microangiopathy with potential for further bleeding. It has also been suggested that matrix metalloproteinases (MMPs) may play a role in blood brain barrier disruption, edema formation and hemorrhagic transformation. In this study, we investigated the relationship between microbleeds detected by GRE, MMPs and neurological worsening in acute lacunar infarctions. METHODS: Eighty-eight patients with acute lacunar infarctions, defined by TOAST classification, were included. GRE (1.5T, TR 500 ms TE 15 ms) was performed within 48 hours after stroke symptom onset. MMPs were measured by standard quantitative sandwich enzyme-linked immunosorbent assays (ELISA). Clinical characteristics, neurologic scale and MMP-9 levels were compared between groups with or without hypointense lesions in GRE (microbleeds). Neurological worsening was defined as deterioration from baseline in the score on the NIHSS by one or more points 14 days after the onset of a lacunar infarction. RESULTS: Eleven of 88 patients (12.5%) undergoing GRE demonstrated evidence of microbleeds in the ischemic region. In the groups with microbleeds, the ESR level (p=0.048) and MMP-9 activity (p=0.001) were significantly increased, and neurological worsening was more prominent (p=0.018). CONCLUSIONS: This study suggests that microbleeds detected by GRE are related with elevated MMP-9 and neurological worsening. Therefore, the finding of microbleeds in GRE, increased MMP-9 activity and elevated ESR level might be useful factors for predicting the progression of acute lacunar infarctions.

Correlation between Multifocal Hypointense Cerebral Lesions on Gradient-echo MRI and White Matter Changes in Patients with Stroke

BACKGROUND: The multifocal hypointense cerebral lesions (MHCLs) on gradient echo (GE)-MRI and white matter changes on T2WI have been thought to be indicative of microangiopathy. The purpose of this study is to elucidate the relationship between MHCLs and white matter (WM) changes and the clinical significance of WM changes in stroke patients. METHODS: We retrospectively reviewed MRI and clinical data of 115 patients with stroke (56 female and 59 male). Periventricular and deep white matter hyperintensity (PVHI and DWMHI) were measured by semiquantative rating scale proposed by Mantyla. The round, hypointense signal, less than 7 mm in diameter on GE-MRI were counted as MHCLs. The association between risk factors of stroke and MHCLs on GE-MRI and sum of the white matter change scores and total number of MHCLs were analyzed, respectively. RESULTS: MHCLs on GE-MRI were significantly associated with old age (p<0.05) and hypertension (p<0.001) among risk factors of stroke. The distribution of MHCLs in subcortical area is associated with hypertension (p<0.05) and total number of MHCLs was significantly associated with sum of the white matter change scores (p<0.05). CONCLUSIONS: MHCLs on GE-MRI were significantly associated with severity of WM changes. Severe WM change may be an indicator of advanced small artery disease of the brain with an increased risk factor for bleeding. This should be taken into consideration when treating patients with stroke.

The Value of Low Field Intensity MR Gradient Echo T_2~*WI in the Diagnosis of Meniscus Injury of the Knee Joint / 实用放射学杂志

Objective To explore the value of low field intensity MR GET2*WI in the diagnosis of meniscus injury.Methods 40 patients with knee injury were examined by various sequences of low field intensity MR to show meniscus.The results of surgery or arthroscopy were acted as diagnostic gold standard of meniscus tear,all samples were confirmed by pathology.Results The sensitivity,specificity and accuracy in diagnosing meniscus tear was 95.65%,92.86% and 94.32% by GET2*WI,and 84.78%,85.71% and 85.23% by FSET2WI respectively.Conclusion Low field intensity MR GET2*WI can show meniscus clearly,it is of significant in the diagnosis of meniscus injury

Clinical Analysis of the Prognosis of the Patients with Cerebral Diffuse Axonal Injuries, Based on Gradient-echo MR Imaging

OBJECTIVES: The authors have studied the clinical outcome of patients with diffuse axonal injuries(DAI) to evaluate the prognostic value of gradient-echo MR imaging findings. MATERIALS AND METHODS: From March 1995 to March 1998, there were nineteen patients with DAI whose initial Glasgow coma scales were eight or less. Authors divided them into two groups according to Glasgow outcome scales;those patients with GOS 3 or less(group A;9) and those with 4 or more(group B;10). We subdivided the lesions as superficial and deep lesion, and analyzed the numbers, anatomical loci of the lesions on the gradient echo images of each group. RESULTS: Mean numbers of the lesions were 15 per case in group A(135/9) and 10 in group B(100/10). The common loci involved in DAI were cerebral cortex, brain stem, and corpus callosum. Cortical lesions were 31.1% in group A(42/135) and 47% in group B(47/100). Brain stem lesions were 25.9%(35/135) and 15%(15/100) each. Callosal lesions were 31.1%(26/135) and 13%(13/100) each. The frequency of callosal and brain stem lesions was significantly different between two groups(p<0.05). We divided callosal lesions as genu, body, and splenium and body lesions as anterior, middle, posterior, but no significant topographical difference of lesions was observed between two groups. Deep lesions were observed more frequently in group A(58.5%, 79/135) than group B(36%, 36/100). CONCLUSION: The poor outcome group showed more numbers of lesion and more frequent involvement of brain stem and corpus callosum than favorable outcome group. Gradient-echo MR imaging seems to have predictive value for clinical outcome in patients with DAI.