Role of magnetic resonance ventriculography in multiloculated hydrocephalus

2013 ◽  
Vol 11 (6) ◽  
pp. 697-703 ◽  
Author(s):  
Gurpreet S. Gandhoke ◽  
Paolo Frassanito ◽  
Nagesh Chandra ◽  
Bal K. Ojha ◽  
Anoop Singh
Keyword(s):  
Magnetic Resonance ◽  
Endoscopic Treatment ◽  
Ventricular System ◽  
Third Ventriculostomy ◽  
Csf Flow ◽  
Reliable Technique ◽  
Accurate Definition ◽  
Multiloculated Hydrocephalus ◽  
Definition Of ◽  
Complex Cases

Object In this paper the authors' goal was to investigate the clinical usefulness of Gd-enhanced MR ventriculography (MRV) in pediatric patients affected by multiloculated hydrocephalus. Methods Eighteen patients (11 boys and 7 girls, age range 2–14 months) with a diagnosis of multiloculated hydrocephalus were included in the study. After injection of gadodiamide (0.02–0.04 mmol) into the lateral ventricle by tapping the anterior fontanel, sagittal, coronal, and axial T1-weighted MR images were acquired. The location of the septations and the sites of obstruction of CSF flow were assessed. Postoperative MRV was obtained to confirm the results of endoscopic treatment in most complex cases. Results No adverse events were observed after injection of contrast medium into the ventricular system. Preoperative MRV accurately defined the exact morphology of septae and ventricular walls in all cases. In 1 case the diagnosis of multiloculated hydrocephalus was ruled out. Sites of obstruction of CSF flow within the ventricular system were also well established. In 4 cases the multiple compartments were proven to intercommunicate. Postoperative MRV was useful in assessing the functional status of third ventriculostomy, aqueductoplasty, and other endoscopic fenestrations. Conclusions Magnetic resonance ventriculography is a safe, effective, and reliable technique. The accurate definition of the anatomy of the ventricles and the site of obstruction in multiloculated hydrocephalus can help to plan the most appropriate treatment and minimize the number of procedures. Although MRV is also useful during postoperative follow-up to determine the results of endoscopic treatment, it should be limited to particularly complex cases, due to its invasiveness.

Role of magnetic resonance imaging in prediction of chondrosarcoma of bone grade

2021 ◽  
pp. 21-24
Author(s):  
A. V. Fedorova ◽  
N. V. Kochergina ◽  
A. B. Bludov ◽  
I. V. Boulycheva ◽  
E. A. Sushentsov ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Diagnostic Value ◽  
Low Grade ◽  
High Grade ◽  
Resonance Imaging ◽  
Accurate Definition ◽  
Definition Of ◽  
Decisive Rule

Purpose. Determining the diagnostic value of magnetic resonance imaging in the accurate definition of chondrosarcoma of bone grade at the pre-surgery examination. Material and methods. We analyzed examination data (magnetic resonance imaging with no contrast enhancement) of 70 patients with chondrosarcoma (35 patients with low-grade chondrosarcoma and 35 patients with high grade chondrosarcoma). Informative weighted coefficients were determined separately for ‘learning’ and ‘examination’ samples. On the basis of weighted coefficients, the decisive rule was created for differentiation between low-grade and high-grade chondrosarcoma. Results. The sensitivity of the method was 87.0%, specificity was 95.6%, total correct classification was 91.03%. Conclusion. Magnetic resonance imaging is a highly informative method for prediction of chondrosarcoma grade at the pre-surgery examination.

Active spontaneous decompression of a suprasellar-prepontine arachnoid cyst detected with routine magnetic resonance imaging

2009 ◽  
Vol 3 (1) ◽  
pp. 70-72 ◽  
Author(s):  
Bradley P. Thomas ◽  
Matthew M. Pearson ◽  
Curtis A. Wushensky
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Arachnoid Cyst ◽  
Male Infant ◽  
Ventricular System ◽  
Arachnoid Cysts ◽  
Resonance Imaging ◽  
Csf Flow ◽  
Routine Magnetic Resonance Imaging

Arachnoid cysts are congenital CSF collections that arise adjacent to arachnoid cisterns. These lesions can be incidental neuroimaging findings but may also cause symptoms and necessitate treatment, particularly in children. The authors present their experience with a male infant harboring a large suprasellar-prepontine arachnoid cyst who underwent spontaneous decompression into the ventricular system, as evidenced by a visualized CSF flow jet observed on routine MR imaging.

Resolution and measurement in the scanning electron microscope

1987 ◽  
Vol 45 ◽  
pp. 534-537 ◽  
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Engineering Design ◽  
Resolving Power ◽  
Practical Applications ◽  
Instrument Resolution ◽  
Accurate Definition ◽  
Definition Of ◽  
Scanning Electron ◽  
Better Than

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.

Dasein, personeidad, intersubjetividad y persona-núcleo. El sujeto relacional después de Heidegger, en Zubiri, Apel y Polo. Dasein, Personhood, Inter-subjectivity and Nucleus-Person. The Relational Subject after Heidegger, in Zubiri, Apel and Polo

2017 ◽  
Author(s):  
Carlos Ortiz de Landázuri
Keyword(s):  
Heuristic Strategies ◽  
Accurate Definition ◽  
Being There ◽  
Definition Of

Heidegger, Zubiri, Apel y Polo habrían propuesto una definición más correcta de las respectivas nociones de sujeto relacional humano, a saber: “Dasein” o “ser-ahí”; “personeidad” o “esencia abierta”; “intersubjetividad” o “la llamada por parte de los entes a diversos interlocutores”; y, finalmente, “persona-núcleo” o “agente mediador entre los entes y el ser”. Se pretendía así evitar una vuelta a las paradojas del “sujeto transcendental” en Kant, del “yo absoluto” en Hegel o del “sujeto fenomenológico” en Husserl. Sin embargo en cada caso se siguieron estrategias heurísticas específicamente distintas a la hora de conceptualizar dicho sujeto relacional: Heidegger propuso una superación de la noción de “sujeto fenomenológico” en Husserl; Zubiri, en cambio, defendería una recuperación de la noción de “sujeto fenomenológico” en Husserl; por su parte, Apel propondría una reformulación semióticamente transformada del “Dasein” heideggeriano; finalmente, Polo propondría una reformulación gnoseológica de la noción de “Dasein” heideggeriano.Heidegger, Zubiri, Apel, and Polo have proposed a more accurate definition of the respective notions of human relational subject: “Dasein” or “being-there”; “Personhood” or “open essence”; “inter-subjectivity” or “entities’ appeal to diverse interlocutors”; and, finally, “nucleus-person” or “mediator between entities and being”. The aim is to avoid a return to Kant’s transcendental subject paradoxes and Hegel’s “absolute I” or Husserl´s “fenomenological subject”. But in each case specifically different heuristic strategies were followed when conceptualizing said relational subject: Heidegger proposed overcoming the notion of “phenomenological subject” in Husserl; Zubiri, however, defend the recovery of the notion of “phenomenological subject” in Husserl; meanwhile, Apel propose a transformed semiotically reformulation of Heidegger’s “Dasein”; finally, Polo propose a reformulation of the epistemological notion of Heidegger’s “Dasein”.

scholarly journals Assessment of Cerebrospinal Fluid Hydrodynamics Using Magnetic Resonance Imaging in Postcraniospinal Surgery Patients

2021 ◽  
Author(s):  
Pankaj Arora ◽  
Kanica Rawat ◽  
Rajiv Azad ◽  
Kehkashan Chouhan
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cerebrospinal Fluid ◽  
Magnetic Resonance ◽  
Clinical Outcome ◽  
Phase Contrast ◽  
Flow Dynamics ◽  
Resonance Imaging ◽  
Csf Flow ◽  
Group I ◽  
Group Ii

Abstract Objective Aim of this study is to evaluate the effect of craniospinal interventions on cerebrospinal fluid (CSF) flow hydrodynamics and study the correlation of postoperative changes in flow alteration with clinical outcome. Materials and Methods Fifty patients who underwent various craniospinal procedures were studied using conventional and phase-contrast magnetic resonance imaging (PCMRI) protocol. CSF flow quantification was performed at cerebral aqueduct, foramen magnum, C2–3, and D12–L1 vertebral levels with site showing maximal alteration of CSF flow dynamics considered as the region of interest. Velocity encoding was kept at 20 cm/s. Patients with pathology atcraniovertebral junction were considered separately (group I) from others (group II) due to different flow dynamics. Follow-up scans were performed after an interval of 1 month for temporal evaluation of changes in CSF flow dynamics. Results Patients in both groups showed a significant change in peak CSF velocity postoperatively (mean change of 1.34 cm/s in group I and 0.28 cm/s in group II) with bidirectional improvement in flow on cine-phase-contrast qualitative images. Regional pain (82%) and headache (46%) were seen in most of the patients preoperatively. Postoperatively clinical symptoms improved in 59.5%, static in 26.2%, and worsened in 14.3%. In both the groups, an improvement in clinical symptomatology had significant correlation with mean changes in peak CSF velocity postoperatively (p = 0.04 in both groups). Conclusion PCMRI can effectively evaluate changes in CSF flow noninvasively both pre- and postoperatively. This may have potential role in determining clinical outcome and prognosis of patients undergoing procedures in craniospinal axis.

scholarly journals Advancing UK Regulatory Science Strategy in the Context of Global Regulation: a Stakeholder Survey

2021 ◽  
Author(s):  
Samantha Cruz Rivera ◽  
Barbara Torlinska ◽  
Eliot Marston ◽  
Alastair K. Denniston ◽  
Kathy Oliver ◽  
...  
Keyword(s):  
Pay For Performance ◽  
Regulatory Science ◽  
International Strategy ◽  
Free Text ◽  
The European Union ◽  
Accurate Definition ◽  
Definition Of ◽  
Healthcare Innovation ◽  
The Uk ◽  
Medium Enterprises

Abstract Background The UK’s transition from the European Union creates both an urgent need and key opportunity for the UK and its global collaborators to consider new approaches to the regulation of emerging technologies, underpinned by regulatory science. This survey aimed to identify the most accurate definition of regulatory science, to define strategic areas of the regulation of healthcare innovation which can be informed through regulatory science and to explore the training and infrastructure needed to advance UK and international regulatory science. Methods A survey was distributed to UK healthcare professionals, academics, patients, health technology assessment agencies, ethicists and trade associations, as well as international regulators, pharmaceutical companies and small or medium enterprises which have expertise in regulatory science and in developing or applying regulation in healthcare. Subsequently, a descriptive quantitative analyses of survey results and directed thematic analysis of free-text comments were applied. Results Priority areas for UK regulatory science identified by 145 participants included the following: flexibility: the capability of regulations to adapt to novel products and target patient outcomes; co-development: collaboration across sectors, e.g. patients, manufacturers, regulators, and educators working together to develop appropriate training for novel product deployment; responsiveness: the preparation of frameworks which enable timely innovation required by emerging events; speed: the rate at which new products can reach the market; reimbursement: developing effective tools to track and evaluate outcomes for “pay for performance” products; and education and professional development. Conclusions The UK has a time-critical opportunity to establish its national and international strategy for regulatory science leadership by harnessing broader academic input, developing strategic cross-sector collaborations, incorporating patients’ experiences and perspectives, and investing in a skilled workforce.

Long-term resolution of acute, obstructive, triventricular hydrocephalus by endoscopic removal of a third ventricular hematoma without third ventriculostomy

2005 ◽  
Vol 102 (5) ◽  
pp. 930-934 ◽  
Author(s):  
Giuseppe M. V. Barbagallo ◽  
Nunzio Platania ◽  
Claudio Schonauer
Keyword(s):  
External Ventricular Drainage ◽  
Third Ventriculostomy ◽  
Endoscopic Removal ◽  
Csf Flow ◽  
Effective Treatment Option ◽  
Content Type ◽  
Duration Of Hospitalization ◽  
Ventricular Hemorrhage ◽  
Triventricular Hydrocephalus

✓ The authors describe a new extension of the use of neuroendoscopy beyond that which is ordinarily performed. The authors report on the resolution of acute, obstructive, triventricular hydrocephalus in a 42-year-old woman with hypertensive caudate hemorrhage that migrated into the ventricular system. The patient underwent emergency endoscopic removal of a third ventricular hematoma, which was obstructing the orifice of the aqueduct, and restoration of cerebrospinal fluid (CSF) flow but no third ventriculostomy. The authors believe that this is the first such case to be reported. In selected cases of third ventricular hemorrhage, endoscopic removal of the intraventricular hematoma may represent a useful and effective treatment option even in emergency conditions as well as a better alternative to prolonged CSF external ventricular drainage. A reduction in the duration of hospitalization is a beneficial consequence. The authors assert that third ventriculostomy is not always needed.

Cervical cytologic abnormalities and negative colposcopy: histologic assessment

1994 ◽  
Vol 4 (5) ◽  
pp. 348-351 ◽  
Author(s):  
R. Chenoy ◽  
S. Manohar ◽  
C. W.E. Redman ◽  
D. M. Luesley
Keyword(s):  
Cervical Cytology ◽  
Histologic Diagnosis ◽  
Abnormal Cervical Cytology ◽  
Accurate Definition ◽  
Cone Biopsy ◽  
Histologic Evaluation ◽  
Simple Regression Analysis ◽  
Definition Of ◽  
Cytologic Abnormalities ◽  
Intraepithelial Lesions

Colposcopic assessment may be normal in the presence of severe or persistent minor cytologic abnormality. To assess the significance of negative satisfactory colposcopy in patients with abnormal cervical smears, a retrospective review was carried out on 1170 patients who had undergone out-patient loop diathermy excision for abnormal cervical cytology. Of these, 69 patients were treated for abnormal cervical cytology, despite normal colposcopic findings. Cytologic abnormalities ranged from persistent borderline changes to severe dyskariosis. Histologic assessment of the excision specimens revealed cervical intraepithalial neoplasia (CIN) in 43 (62.3%) cases, of which high-grade CIN accounted for 24 (34.8%) cases. There was good correlation between cytologic and histologic diagnosis. Simple regression analysis showedr= 0.46,P< 0.0001. The cytologic abnormality was highly predictive of the corresponding histologic diagnosis. This analysis has shown that significant intraepithelial lesions may exist despite negative colposcopic examination and highlights the need for histologic evaluation in such cases. In these circumstances, loop cone biopsy permits accurate definition of lesion severity, avoids potential undertreatment of significant lesions and causes less morbidity than conventional cone biopsy.

Theism and Hypertheism

1943 ◽  
Vol 36 (1) ◽  
pp. 63-81
Author(s):  
John Laird
Keyword(s):  
Accurate Definition ◽  
Definition Of

Theists, I suppose, are persons who believe in “God's” existence. Atheists are persons who deny the same.Such statements may be suitable, and even adequate, for many proper purposes. In several contexts it is silly or malicious to interrogate them closely. Even in theology, which is, or should be, some kind of science, they may have, and they do have, their use and their propriety. For many theological purposes, however (and also for some others) they are far too vague. It may be wrong, no doubt, to tell a theologian that he must either produce an accurate definition of what he means by “God” or be forever shamed.

scholarly journals Reasons for discordances between ultrasonography and magnetic resonance imaging in the evaluation of the ankle, hindfoot and heel of the patients with rheumatoid arthritis

2019 ◽  
Vol 21 (4) ◽  
pp. 405 ◽  
Author(s):  
Oana Șerban ◽  
Daniela Fodor ◽  
Iulia Papp ◽  
Mihaela Cosmina Micu ◽  
Dan Gabriel Duma ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Disease Activity ◽  
Activity Index ◽  
Imaging Techniques ◽  
Disease Activity Index ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Definition Of

Aim: To compare the ultrasonography (US) performance with magnetic resonance imaging (MRI) in identifying pathology in ankles, hindfeet and heels of rheumatoid arthritis (RA) patients and to evaluate the reasons for discordances between the two imaging methods.Material and methods: RA patients were enrolled and evaluated using the Clinical Disease Activity Index (CDAI) and the Disease Activity Score 28 with C-reactive Protein (DAS28-CRP). The ankle (tibiotalar joint, tendons), hindfoot (talonavicular, subtalar joints) and heel of the most symptomatic or dominant foot (for the asymptomatic patient)were evaluated by two pairs of examiners using US and contrast-enhanced MRI.Results: Totally, 105 joints, 245 tendons and 35 heels in 35 patients [mean age 59.2±11.25 years old, median disease duration 36 (16.5-114), mean CDAI 19.87±12.7] were evaluated. The interobserver agreements between the two sonographers, and the two radiologists were good and very good (k=0.624-0.940). The overall agreement between US and MRI was very good for subcalcaneal panniculitis (k=0.928, p<0.001), moderate for synovitis (k=0.463, p<0.001) and tenosynovitis (k=0.514, p<0.001), fair for osteophytes (k=0.260, p=0.004), and poor for erosions (k=0.063, p=0.308) and heel’s structures. MRI found more erosions, synovitis, osteophytes,tenosynovitis and retrocalcaneal bursitis, but US found more enthesophytes and plantar fasciitis. Many of the discordancesbetween the two imaging techniques have explanations related to the technique itself or definition of the pathologic findings.Conclusions: US is comparable to MRI for the evaluation of ankle, hindfoot and heel in RA patients and discordances in theinterpretation of the pathological findings/normal structures must be carefully analyzed.

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