Magnetic resonance imaging for quantitative flow measurement in infants with hydrocephalus: a prospective study

2008 ◽  
Vol 2 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Paul H. Leliefeld ◽  
Rob H. J. M. Gooskens ◽  
Koen L. Vincken ◽  
Lino M. P. Ramos ◽  
Jeroen van der Grond ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Pressure ◽  
Mr Angiography ◽  
Surgical Intervention ◽  
Clinical Signs ◽  
Resonance Imaging ◽  
Arterial Blood ◽  
Before And After ◽  
Csf Diversion ◽  
The Mean

Object Raised intracranial pressure (ICP) that is associated with hydrocephalus may lead to alterations in cerebral hemodynamics and ischemic changes in the brain. In infants with hydrocephalus, defining the right moment for surgical intervention based on clinical signs alone can sometimes be a difficult task. Clinical signs of raised ICP are known to be unreliable and sometimes even misleading. Furthermore, when sutures are closed, ICP does not always correlate with the size of the ventricles or with the clinical signs or symptoms. In this study the authors investigated whether cerebral blood flow (CBF) can be measured by using quantitative MR angiography in infants with progressive hydrocephalus. In addition, the authors investigated the relationship between CBF and ICP, before and after cerebrospinal fluid (CSF) diversion. Methods Fifteen infants with progressive hydrocephalus (age range 1 day–7 months) were examined. All patients underwent anterior fontanel pressure measurement, MR angiography, and mean arterial blood pressure measurements before and after CSF diversion. Brain volume was measured to compensate for the physiological increase in CBF during brain maturation in infants. Results The mean preoperative ICP was 19.1 ± 8.4 cm H2O (± standard deviation). The mean postoperative ICP was 6.7 ± 4.0 cm H2O (p < 0.005). The mean preoperative CBF was 25.7 ± 11.3 ml/100 cm3 brain/min. After CSF diversion, CBF increased to 50.1 ± 12.1 ml/100 cm3 brain/min (p < 0.005). The mean arterial blood pressure did not change after surgical intervention. Conclusions Magnetic resonance imaging can be used to measure CBF in infants with hydrocephalus. Raised ICP was related to a decrease in CBF. After CSF diversion, CBF and ICP improved to values within the normal range.

scholarly journals “Yokoyama procedure” efficacy on non-highly myopic patients with acquired esotropia and hypotropia

2019 ◽  
Vol 30 (4) ◽  
pp. 676-679
Author(s):  
Massimiliano Serafino ◽  
Matteo Scaramuzzi ◽  
Edoardo Villani ◽  
Paolo Nucci
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Axial Length ◽  
Lateral Rectus ◽  
Inclusion Criteria ◽  
Resonance Imaging ◽  
Spherical Equivalent Refraction ◽  
Before And After ◽  
Weighted Magnetic Resonance Imaging ◽  
The Mean

Objective: To assess the efficacy of “Yokoyama Procedure,” on non-highly myopic patients with acquired esotropia and hypotropia. Methods: The study involved 10 eyes of 5 patients with eso-hypotropia. Inclusion criteria were acquired esotropic-hypotropic strabismus with lateral rectus inferior displacement and superior rectus nasal displacement confirmed by magnetic resonance imaging, refractive errors between ±6 D, and axial length < 27 mm. Range of full duction movements and maximum angles of abduction-sursumduction was measured in each eye before and after surgery. All patients underwent T1- and T2-weighted magnetic resonance imaging. The surgery was aimed at creating a junction between the muscle bellies of the superior and lateral rectus muscles. This junction was made approximately 14 mm behind the insertions using a non-absorbable mersilene 5/0 suture (Yokoyama procedure). Results: Mean patient age was 64.8 ± 4.8 years. The mean globe axial length was 25.4 ± 0.76 mm and a mean corresponding spherical equivalent refraction of −3.7 ± 1.7 D was observed. Eight eyes on 10 had mild limitation in abduction, while the remaining 2 had no limitation. Three out of 10 eyes showed a moderate limited sursumduction, 5 eyes were categorized as mild, and the remaining 2 had no limitation. No evident post-operative limitation was present in any eye, in both abduction and sursumduction (p < 0.01). Pre-operative esotropia and hypotropia were, respectively, 32 ± 11 prismatic diopters and 25 ± 5 prismatic diopters, and they were significantly reduced after surgery as 9 ± 1.7 prismatic diopters and 6 ±1 prismatic diopters (p = 0.043), respectively. Conclusion: Yokoyama procedure is an effective, fast, reversible procedure to face eso-hypotropic acquired strabismus, even in patients with a clear magnetic resonance imaging displacement of superior and lateral rectus muscles, and absence of globe dislocation and of elevated myopia.

scholarly journals Why Blood Pressure and Body Mass Should be Controlled for in Resting-State Functional Magnetic Resonance Imaging Studies.

2021 ◽  
Author(s):  
Guro Stensby Sjuls ◽  
Karsten Specht
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Pressure ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Body Mass ◽  
Resting State ◽  
Bold Signal ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Arterial Blood

Replicability has become an increasing focus within the scientific communities with the ongoing "replication crisis". One area that appears to struggle with unreliable results is resting-state functional magnetic resonance imaging (rs-fMRI). Therefore, the current study aimed to improve the knowledge of endogenous factors that contribute to inter-individual variability. Arterial blood pressure, body mass, hematocrit, and glycated hemoglobin were investigated as potential sources of between-subject variability in rs-fMRI, in healthy individuals. Whether changes in resting state-networks (rs-networks) could be attributed to variability in the BOLD-signal, changes in neuronal activity, or both, was of special interest. Within-subject parameters were estimated utilizing Dynamic Causal Modelling (DCM) as it allows to make inferences on the estimated hemodynamic (BOLD-signal dynamics) and neuronal parameters (effective connectivity) separately. The results of the analyses imply that blood pressure and body mass can cause between-subject and between-group variability in the BOLD-signal and that all the included factors can affect the underlying connectivity. Given the results of the current and previous studies, rs-fMRI results appear to be susceptible to a range of factors, which is likely to contribute to the low degree of replicability of these studies. Interestingly, the highest degree of variability seems to appear within the much-studied Default Mode Network and its connections to other networks.

O-146 Assessment of focal and diffuse adenomyosis lesions before and after pregnancy on magnetic resonance imaging : a cohort of 139 patients

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
L Legay ◽  
L Marcellin ◽  
P Santulli ◽  
A E Millischer ◽  
C Bordonne ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Time Interval ◽  
Resonance Imaging ◽  
Junctional Zone ◽  
Pelvic Magnetic Resonance Imaging ◽  
Before And After ◽  
The Mean ◽  
The Impact ◽  
Mean Time

Abstract Study question How to assess the different adenomyosis phenotype before and after pregnancy on magnetic resonance imaging according to stringent validated criteria ? Summary answer Diffuse adenomyosis increases significantly after pregnancy while the rate of focal adenomyosis and the mean volume of focal adenomyosis lesions decrease significantly after pregnancy. What is known already Adenomyosis and endometriosis are benign hormone-dependent disorders associated with pelvic pain, dysmenorrhea and/or infertility. The natural course of adenomyosis and endometriosis is still unclear, particularly during pregnancy. Pregnancy is considered to have a positive impact on endometriosis. Several studies regarding the impact of adenomyosis on pregnancy are available. Adenomyosis can cause fertility disorders, miscarriage, preterm birth. However, available data evaluating the effect of pregnancy on adenomyosis are lacking. Study design, size, duration Between January 1st 2010 and September 30th 2020, 139 patients were followed in our referral care center (Gynecology department of Port-Royal Hospital, Paris) for symptomatic adenomyosis and or endometriosis. For each of them, a magnetic resonance imaging were performed before and after pregnancy. The data based on magnetic resonance imaging, pre- and post-pregnancy, were analyzed in a single retrospective study. Participants/materials, setting, methods Patients had to be over 18 years old, to be pregnant and to be followed for symptomatic adenomyosis or endometriosis without any previous surgery. Each pelvic magnetic resonance imaging were performed by a single experienced radiologist. The protocol was identical on a 1.5 T magnetic resonance imaging machine based on validated criteria. The rate of diffuse and focal adenomyosis, the volume of focal adenomyosis lesions and the thickness of maximal junctional zone were reported. Main results and the role of chance The mean age of patients was 34.6 ± 3.4 years old, 83 (59.7%) of patients underwent assisted reproductive technology to be pregnant. The mean time interval between the MRI and the delivery was 55.2 months and the mean time interval between the delivery and the MRI was 32.2 months. Before pregnancy, there was 96 (69.1%) patients with adenomyosis, all phenotype combined versus 111 (79.9%) after pregnancy (p = 0.04) on magnetic resonance imaging. The rate of diffuse adenomyosis increased significantly on magnetic resonance imaging after pregnancy compared to before pregnancy (n = 22 (15.8%) vs n = 41 (29.5%), p = 0.01). The thickness of junctional zone maximal was significantly higher after pregnancy (8.0 mm ± 5.1 vs 12.0 mm ± 4.8, p &lt; 0.01). The rate of focal adenomyosis (n = 55 (39.6) vs n = 34 (24.5), p = 0.01) as well as the volume of focal adenomyosis lesions (6.7 mm3 2.5± vs 6.4 mm3 ± 2.3, p &lt; 0.01) decreased significantly after pregnancy on magnetic resonance imaging. Limitations, reasons for caution This single-center study was conducted in a referral center whom patients presented more severe forms of adenomyosis, which could have affected the external validity of this study. The mean time interval between delivery and MRI was 32.2 month which implies a short follow up period to observe long term outcomes. Wider implications of the findings The hypothesis that a specific hormonal environment during pregnancy may imply a positively impact of the evolution of focal adenomyosis is raised by this study. The evolution of focal adenomyosis after pregnancy is similar to the evolution of endometriosis lesions volume that support shared etiopathogenic mechanisms between the two entities. Trial registration number ‘not applicable’

scholarly journals Magnetic Resonance Imaging of the Knee in the Presence of Bridging External Fixation: A Comparative Experimental Evaluation of Four External Fixators, Including Dolphix®

2021 ◽  
Vol 7 (1) ◽  
pp. 4
Author(s):  
Francesco Addevico ◽  
Alberto Simoncini ◽  
Giovanni Solitro ◽  
Massimo Max Morandi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Regions Of Interest ◽  
Lower Limbs ◽  
External Fixators ◽  
Resonance Imaging ◽  
Signal To Noise ◽  
Mr Conditional ◽  
Before And After ◽  
The Mean

Performing MR investigation on patients instrumented with external fixators is still controversial. The aim of this study is to evaluate the quality of MR imaging of the knee structures in the presence of bridging external fixators. Different cadaveric lower limbs were instrumented with the MR-conditional external fixators Hofmann III (Stryker, Kalamazoo, MI, USA), Large external Fixator (DePuy Synthes, Raynham, MA, USA), XtraFix (Zymmer, Warsaw, IN, USA) and a newer implant of Ketron Peek CA30 and ERGAL 7075 pins, Dolphix®, (Citieffe, Bologna, Italy). The specimens were MR scanned before and after the instrumentation. The images were subjectively judged by a pool of blinded radiologists and then quantitatively evaluated calculating signal intensity, signal to noise and contrast to noise in the five regions of interest. The area of distortion due to the presence of metallic pins was calculated. All the images were considered equally useful for diagnosis with no differences between devices (p > 0.05). Only few differences in the quantification of images have been detected between groups while the presence of metallic components was the main limit of the procedure. The mean length of the radius of the area of distortion of the pins were 53.17 ± 8.19 mm, 45.07 ± 4.33 mm, 17 ± 5.4 mm and 37.12 ± 10.17 mm per pins provided by Zimmer, Synthes, Citieffe and Stryker, respectively (p = 0.041). The implant of Ketron Peek CA30 and ERGAL 7075 pins showed the smallest distortion area.

The Kaplan Fibers of the Iliotibial Band Can Be Identified on Routine Knee Magnetic Resonance Imaging

2019 ◽  
Vol 47 (12) ◽  
pp. 2895-2903 ◽  
Author(s):  
Lachlan Batty ◽  
Jerome Murgier ◽  
Richard O’Sullivan ◽  
Kate E. Webster ◽  
Julian A. Feller ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Sagittal Plane ◽  
Interobserver Reliability ◽  
Joint Line ◽  
Coronal Plane ◽  
Iliotibial Band ◽  
Resonance Imaging ◽  
Lateral Gastrocnemius ◽  
The Mean

Background: The Kaplan fibers (KFs) of the iliotibial band have been suggested to play a role in anterolateral rotational instability of the knee, particularly in the setting of an anterior cruciate ligament (ACL) rupture. Description of the normal magnetic resonance imaging (MRI) anatomy of the KFs may facilitate subsequent investigation into the MRI signs of injury. Purpose: To assess if the KF complex can be identified on 3-T MRI using standard knee protocols. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: 3-T MRI scans of 50 ACL-intact knees were reviewed independently by a musculoskeletal radiologist and 2 orthopaedic surgeons. Identification of the KFs was based on radiological diagnostic criteria developed a priori. Identification of the KFs in the sagittal, coronal, and axial planes was recorded. Interobserver reliability was assessed using the Kappa statistic. Detailed anatomy including distance to the joint line and relationship to adjacent structures was recorded. Results: The mean patient age was 43 years (range, 15-81 years), 58% were male, and 50% were right knees. The KFs were identified by at least 2 reviewers on the sagittal images in 96% of cases, on the axial images in 76% of cases, and on the coronal images in 4% of cases. The mean distance from the KF distal femoral insertion to the lateral joint line was 50.1 mm (SD, 6.6 mm) and the mean distance to the lateral gastrocnemius tendon origin was 10.8 mm (SD, 8.6 mm). The KFs were consistently identified immediately anterior to the superior lateral geniculate artery on sagittal imaging. Interobserver reliability for identification was best in the sagittal plane (Kappa 0.5) and worst in the coronal plane (Kappa 0.1). Conclusion: The KF complex can be identified on routine MRI sequences in the ACL-intact knee; however, there is low to moderate interobserver reliability. Imaging in the sagittal plane had the highest rate of identification and the coronal plane the lowest. There is a consistent relationship between the most distal KF femoral attachment and the lateral joint line, lateral gastrocnemius tendon, and superior lateral geniculate artery.

scholarly journals Changes of Dorsal Root Ganglion Volume in Dogs with Clinical Signs of Degenerative Myelopathy Detected by Water-Excitation Magnetic Resonance Imaging

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1702
Author(s):  
Eiji Naito ◽  
Kohei Nakata ◽  
Yukiko Nakano ◽  
Yuta Nozue ◽  
Shintaro Kimura ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Spinal Cord ◽  
Magnetic Resonance ◽  
Clinical Signs ◽  
Intervertebral Disc Herniation ◽  
Resonance Imaging ◽  
Diagnostic Potential ◽  
Water Excitation ◽  
Spinal Cord Segment ◽  
Degenerative Myelopathy

Canine degenerative myelopathy (DM) is a progressive and fatal neurodegenerative disease. However, a definitive diagnosis of DM can only be achieved by postmortem histopathological examination of the spinal cord. The purpose of this study was to investigate whether the volumetry of DRG using the ability of water-excitation magnetic resonance imaging (MRI) to visualize the DRG in dogs has premortem diagnostic value for DM. Eight dogs with DM, twenty-four dogs with intervertebral disc herniation (IVDH), and eight control dogs were scanned using a 3.0-tesla MRI system, and water-excitation images were obtained to visualize and measure the volume of DRG, normalized by body surface area. The normalized mean DRG volume between each spinal cord segment and mean volume of all DRG between T8 and L2 in the DM group was significantly lower than that in the control and the IVDH groups (P = 0.011, P = 0.002, respectively). There were no correlations within the normalized mean DRG volume between DM stage 1 and stage 4 (rs = 0.312, P = 0.128, respectively). In conclusion, DRG volumetry by the water-excitation MRI provides a non-invasive and quantitative assessment of neurodegeneration in DRG and may have diagnostic potential for DM.

scholarly journals Demyelination and remyelination detected in an alternative cuprizone mouse model of multiple sclerosis with 7.0 T multiparameter magnetic resonance imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuang Ding ◽  
Yu Guo ◽  
Xiaoya Chen ◽  
Silin Du ◽  
Yongliang Han ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Mouse Model ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Blue Staining ◽  
Resonance Imaging ◽  
The Mean ◽  
Underlying Mechanisms

AbstractThe aim of this study was to investigate the mechanisms underlying demyelination and remyelination with 7.0 T multiparameter magnetic resonance imaging (MRI) in an alternative cuprizone (CPZ) mouse model of multiple sclerosis (MS). Sixty mice were divided into six groups (n = 10, each), and these groups were imaged with 7.0 T multiparameter MRI and treated with an alternative CPZ administration schedule. T2-weighted imaging (T2WI), susceptibility-weighted imaging (SWI), and diffusion tensor imaging (DTI) were used to compare the splenium of the corpus callosum (sCC) among the groups. Prussian blue and Luxol fast blue staining were performed to assess pathology. The correlations of the mean grayscale value (mGSV) of the pathology results and the MRI metrics were analyzed to evaluate the multiparameter MRI results. One-way ANOVA and post hoc comparison showed that the normalized T2WI (T2-nor), fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) values were significantly different among the six groups, while the mean phase (Φ) value of SWI was not significantly different among the groups. Correlation analysis showed that the correlation between the T2-nor and mGSV was higher than that among the other values. The correlations among the FA, RD, MD, and mGSV remained instructive. In conclusion, ultrahigh-field multiparameter MRI can reflect the pathological changes associated with and the underlying mechanisms of demyelination and remyelination in MS after the successful establishment of an acute CPZ-induced model.

scholarly journals Multiple b values of diffusion-weighted magnetic resonance imaging in evaluation of solid head and neck masses

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Rania Sobhy Abou khadrah ◽  
Haytham Haroon Imam
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Head And Neck ◽  
Resonance Imaging ◽  
Adc Value ◽  
Neck Masses ◽  
Adc Values ◽  
Weighted Magnetic Resonance Imaging ◽  
The Mean ◽  
Head And Neck Masses

Abstract Background Differentiation between malignant and benign masses is essential for treatment planning and helps in improving the prognosis of malignant tumors; the aim of this work is to determine the role of diffusion-weighted magnetic resonance imaging (DW-MRI) and the apparent diffusion coefficient (ADC) in the differentiation between benign and malignant solid head and neck masses by comparing diagnostic performance of low b values (0.50 and 400 s/mm2) versus high b values (800 and 1000 s/mm2) and comparing the result with histopathological finding. Results The study included 60 patients (34 male and 26 female) with solid head and neck masses > 1 cm who referred to radiodiagnosis department for MRI evaluation. Multiple b values were used 50, 400, 800, and 1000 s/mm2 (at least 2 b values). DWI and ADC value of all 60 patients were acquired. Mean ADC values of both malignant and benign masses were statistically measured and compared, and cut off value was determined. Solid head and neck masses in our study DWI with the use of high b value 800 and 1000 s/mm2 were of higher significance (P value 0.001*). There was a significant difference in the mean ADC value between benign and malignant masses (P < 0.01); solid masses were divided into 2 categories: (a) malignant lesions 46.7% (n = 28) with mean ADC value (0.82 ± 0.19) × 10−3 s/mm2 and (b) benign lesions 53.3% (n = 32) with mean ADC value (2.05 ± 0.46) × 10−3 s/mm2) with ADC cutoff value of 1.0 × 10−3 s/mm2 and 94% sensitivity, 93% specificity, negative predictive value (NPV) = 94%, positive predictive value (PPV) 93%, and an accuracy of 93.5%. Conclusion The DWI with ADC mapping were valuable as non-invasive tools in differentiating between benign and malignant solid head and neck masses. The use of high b value 800 and 1000 s/mm2 was of higher significance (P value 0.001*) in differentiation between benign and malignant lesion than that with low b values 0, 50, and 400 s/mm2 (0.01). The mean ADC values were significantly lower in malignant solid masses. Attention had to be paid to the choice of b values in MRI-DWI in the head and neck region.

scholarly journals On the Pathology of the dropsy produced by obstruction of the superior and inferior venœ and the portal vein.— Preliminary communication

1907 ◽  
Vol 79 (532) ◽  
pp. 267-283 ◽  
Keyword(s):  
Blood Pressure ◽  
Arterial Pressure ◽  
Portal Vein ◽  
Mean Arterial Blood Pressure ◽  
Normal Limit ◽  
The Body ◽  
Diastolic Filling ◽  
Arterial Blood ◽  
Preliminary Communication ◽  
The Mean

In August, 1903, I published a paper in the ‘Journal of Pathology’(1) in which I demonstrated a method experimentally producing uncompensated hear disease in an animal, which was compatible with life. This method consisted in diminishing the size of the pericardial sac by stitches, so that the diastolic filling of the heart was impeded. The main symptoms of this condition were dropsy and diminution in the amount of urine excreted. As the immediate result of this interference with the action of the heart, there occurred a rise of pressure throughout the whole systemic venous system extending as far back as the capillaries, and a fall of the mean arterial blood-pressure. Further, I found that the pressure in all the veins fell to the normal limit again within the space of about one hour, and that subsequently when dropsy was being produced, the vanous pressure in all parts of the body was normal, and the arterial pressure had almost recovered itself.

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