Cerebrovascular Manifestations of Neurosarcoidosis: An Underrecognized Aspect of the Imaging Spectrum.

Related Articles

Cerebrovascular Manifestations of Neurosarcoidosis: An Underrecognized Aspect of the Imaging Spectrum.

AJNR Am J Neuroradiol. 2017 Dec 28;:

Authors: Bathla G, Watal P, Gupta S, Nagpal P, Mohan S, Moritani T

Abstract
Involvement of the central nervous system by sarcoidosis, also referred to as neurosarcoidosis, is seen clinically in about 5% of patients with systemic disease. CNS involvement most frequently affects the leptomeninges and cranial nerves, though the ventricular system, brain parenchyma, and pachymeninges may also be involved. Even though the involvement of the intracranial vascular structures is well-known on postmortem studies, there is scant literature on imaging manifestations secondary to the vessel wall involvement, being confined mostly to isolated case reports and small series. The authors present a review of various cerebrovascular manifestations of neurosarcoidosis, along with a brief synopsis of the existing literature.

PMID: 29284603 [PubMed - as supplied by publisher]

from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2Cp4I37

Cervical Cord Atrophy and Long-Term Disease Progression in Patients with Primary-Progressive Multiple Sclerosis.

Related Articles

Cervical Cord Atrophy and Long-Term Disease Progression in Patients with Primary-Progressive Multiple Sclerosis.

AJNR Am J Neuroradiol. 2017 Dec 28;:

Authors: Aymerich FX, Auger C, Alonso J, Alberich M, Sastre-Garriga J, Tintoré M, Montalban X, Rovira A

Abstract
BACKGROUND AND PURPOSE: Cervical cord atrophy has been associated with clinical disability in multiple sclerosis and is proposed as an outcome measure of neurodegeneration. The aim of this study was to quantify the development of cervical cord atrophy and to evaluate its association with disability progression in patients with primary-progressive multiple sclerosis.
MATERIALS AND METHODS: Thirty-one patients with primary-progressive multiple sclerosis underwent 1.5T brain and spinal cord MR imaging at baseline and 6-7 years later. The cervical spinal cord from C1 to C5 was segmented to evaluate the normalized overall cross-sectional area and the cross-sectional area of C2-C3, C3-C4, and C4-C5. The annualized rates of normalized cross-sectional area loss were also evaluated. To estimate clinical progression, we determined the Expanded Disability Status Scale score at baseline and at 2 and 14 years after baseline to compute the normalized area under the curve of the Expanded Disability Status Scale and the Expanded Disability Status Scale changes from baseline to the follow-up time points. Associations between the cord cross-sectional area and brain MR imaging and clinical measures were also investigated. Finally, the value of all these measures for predicting long-term disability was evaluated.
RESULTS: Some normalized cross-sectional area measurements showed moderate correlations with the normalized area under the curve of the Expanded Disability Status Scale, ranging from -0.439 to -0.359 (P < .05). Moreover, the annualized rate of the normalized mean cross-sectional area loss and the baseline Expanded Disability Status Scale were independent predictors of long-term disability progression.
CONCLUSIONS: These data indicate that development of cervical cord atrophy is associated with progression of disability and is predictive of this event in patients with primary-progressive MS.

PMID: 29284602 [PubMed - as supplied by publisher]

from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2CqaH7Y

Clinical and Radiologic Characteristics of Deep Lumbosacral Dural Arteriovenous Fistulas.

Related Articles

Clinical and Radiologic Characteristics of Deep Lumbosacral Dural Arteriovenous Fistulas.

AJNR Am J Neuroradiol. 2017 Dec 28;:

Authors: Jablawi F, Nikoubashman O, Schubert GA, Dafotakis M, Hans FJ, Mull M

Abstract
BACKGROUND AND PURPOSE: Spinal dural arteriovenous fistulas located in the deep lumbosacral region are rare and the most difficult to diagnose among spinal dural arteriovenous fistulas located elsewhere in the spinal dura. Specific clinical and radiologic features of these fistulas are still inadequately reported and are the subject of this study.
MATERIALS AND METHODS: We retrospectively evaluated all data of patients with spinal dural arteriovenous fistulas treated and/or diagnosed in our institution between 1990 and 2017. Twenty patients with deep lumbosacral spinal dural arteriovenous fistulas were included in this study.
RESULTS: The most common neurologic findings at the time of admission were paraparesis (85%), sphincter dysfunction (70%), and sensory disturbances (20%). Medullary T2 hyperintensity and contrast enhancement were present in most cases. The filum vein and/or lumbar veins were dilated in 19/20 (95%) patients. Time-resolved contrast-enhanced dynamic MRA indicated a spinal dural arteriovenous fistula at or below the L5 vertebral level in 7/8 (88%) patients who received time-resolved contrast-enhanced dynamic MRA before DSA. A bilateral arterial supply of the fistula was detected via DSA in 5 (25%) patients.
CONCLUSIONS: Clinical symptoms caused by deep lumbosacral spinal dural arteriovenous fistulas are comparable with those of spinal dural arteriovenous fistulas at other locations. Medullary congestion in association with an enlargement of the filum vein or other lumbar radicular veins is a characteristic finding in these patients. Spinal time-resolved contrast-enhanced dynamic MRA facilitates the detection of the drainage vein and helps to localize deep lumbosacral-located fistulas with a high sensitivity before DSA. Definite detection of these fistulas remains challenging and requires sufficient visualization of the fistula-supplying arteries and draining veins by conventional spinal angiography.

PMID: 29284601 [PubMed - as supplied by publisher]

from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2CqoX0k

MR Imaging Criteria for the Detection of Nasopharyngeal Carcinoma: Discrimination of Early-Stage Primary Tumors from Benign Hyperplasia.

Related Articles

MR Imaging Criteria for the Detection of Nasopharyngeal Carcinoma: Discrimination of Early-Stage Primary Tumors from Benign Hyperplasia.

AJNR Am J Neuroradiol. 2017 Dec 28;:

Authors: King AD, Wong LYS, Law BKH, Bhatia KS, Woo JKS, Ai QY, Tan TY, Goh J, Chuah KL, Mo FKF, Chan KCA, Chan ATC, Vlantis AC

Abstract
BACKGROUND AND PURPOSE: MR imaging can detect nasopharyngeal carcinoma that is hidden from endoscopic view, but for accurate detection carcinoma confined within the nasopharynx (stage T1) must be distinguished from benign hyperplasia of the nasopharynx. This study aimed to document the MR imaging features of stage T1 nasopharyngeal carcinoma and to attempt to identify features distinguishing it from benign hyperplasia.
MATERIALS AND METHODS: MR images of 189 patients with nasopharyngeal carcinoma confined to the nasopharynx and those of 144 patients with benign hyperplasia were reviewed and compared in this retrospective study. The center, volume, size asymmetry (maximum percentage difference in area between the right and left nasopharyngeal halves), signal intensity asymmetry, deep mucosal white line (greater contrast enhancement along the deep tumor margin), and absence/distortion of the adenoidal septa were evaluated. Differences were assessed with logistic regression and the χ2 test.
RESULTS: The nasopharyngeal carcinoma center was lateral, central, or diffuse in 134/189 (70.9%), 25/189 (13.2%), and 30/189 (15.9%) cases, respectively. Nasopharyngeal carcinomas involving the walls showed that a deep mucosal white line was present in 180/183 (98.4%), with a focal loss of this line in 153/180 (85%) cases. Adenoidal septa were absent or distorted in 111/111 (100%) nasopharyngeal carcinomas involving the adenoid. Compared with benign hyperplasia, nasopharyngeal carcinoma had a significantly greater volume, size asymmetry, signal asymmetry, focal loss of the deep mucosal white line, and absence/distortion of the adenoidal septa (P < .001). Although size asymmetry was the most accurate criterion (89.5%) for nasopharyngeal carcinoma detection, use of this parameter alone would have missed 11.9% of early-stage T1 nasopharyngeal carcinomas.
CONCLUSIONS: MR imaging features can help distinguish stage T1 nasopharyngeal carcinoma from benign hyperplasia in most cases.

PMID: 29284600 [PubMed - as supplied by publisher]

from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2CrxpN5

Spinal Arteriovenous Vascular Malformations in Patients with Neural Tube Defects.

Related Articles

Spinal Arteriovenous Vascular Malformations in Patients with Neural Tube Defects.

AJNR Am J Neuroradiol. 2017 Dec 28;:

Authors: Giordan E, Bortolotti C, Lanzino G, Brinjikji W

Abstract
BACKGROUND AND PURPOSE: Neural tube defects, such as tethered cord, intradural lipoma, or myelomeningocele may coexist with spinal vascular malformations. The coexistence of these 2 rare entities is suggestive of a causal relationship between them, which may lead to further understanding of their pathogenesis. We present a series of 6 patients with epidural spinal arteriovenous fistulas associated with neural tube defects.
MATERIALS AND METHODS: We retrieved cases of spinal vascular malformations associated with neural tube defects seen at our institution. The clinical presentation, MR imaging/MRA and angiographic imaging, treatment outcomes, and long-term neurologic outcomes were analyzed. Descriptive statistical analyses are reported.
RESULTS: Six patients with epidural arteriovenous fistulas and neural tube defects were included in this study. The mean age at presentation was 42 years, and the most common presenting symptoms were lower extremity weakness followed by sensory disturbances and bladder/bowel dysfunction. In most cases (5/6), the fistulas were located at the sacral level. All cases were fed by the lateral sacral artery (6/6). Four patients had prior spine surgery, but the fistula was in the operative bed in 2 cases. All fistulas were extradural with secondary intradural venous drainage. Five patients underwent transarterial embolization with Onyx, and 1 patient had a treatment-related complication.
CONCLUSIONS: It is conceivable that there is a pathophysiologic link between neural tube defects and development of spinal vascular malformations. Delayed neurologic deterioration or high conus signal in a patient with a neural tube defect should suggest the possibility of such an association.

PMID: 29284599 [PubMed - as supplied by publisher]

from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2CqUAH5

Noninvasive Assessment of Intracranial Pressure Status in Idiopathic Intracranial Hypertension Using Displacement Encoding with Stimulated Echoes (DENSE) MRI: A Prospective Patient Study with Contemporaneous CSF Pressure Correlation.

Related Articles

Noninvasive Assessment of Intracranial Pressure Status in Idiopathic Intracranial Hypertension Using Displacement Encoding with Stimulated Echoes (DENSE) MRI: A Prospective Patient Study with Contemporaneous CSF Pressure Correlation.

AJNR Am J Neuroradiol. 2017 Dec 28;:

Authors: Saindane AM, Qiu D, Oshinski JN, Newman NJ, Biousse V, Bruce BB, Holbrook JF, Dale BM, Zhong X

Abstract
BACKGROUND AND PURPOSE: Intracranial pressure is estimated invasively by using lumbar puncture with CSF opening pressure measurement. This study evaluated displacement encoding with stimulated echoes (DENSE), an MR imaging technique highly sensitive to brain motion, as a noninvasive means of assessing intracranial pressure status.
MATERIALS AND METHODS: Nine patients with suspected elevated intracranial pressure and 9 healthy control subjects were included in this prospective study. Controls underwent DENSE MR imaging through the midsagittal brain. Patients underwent DENSE MR imaging followed immediately by lumbar puncture with opening pressure measurement, CSF removal, closing pressure measurement, and immediate repeat DENSE MR imaging. Phase-reconstructed images were processed producing displacement maps, and pontine displacement was calculated. Patient data were analyzed to determine the effects of measured pressure on pontine displacement. Patient and control data were analyzed to assess the effects of clinical status (pre-lumbar puncture, post-lumbar puncture, or control) on pontine displacement.
RESULTS: Patients demonstrated imaging findings suggesting chronically elevated intracranial pressure, whereas healthy control volunteers demonstrated no imaging abnormalities. All patients had elevated opening pressure (median, 36.0 cm water), decreased by the removal of CSF to a median closing pressure of 17.0 cm water. Patients pre-lumbar puncture had significantly smaller pontine displacement than they did post-lumbar puncture after CSF pressure reduction (P = .001) and compared with controls (P = .01). Post-lumbar puncture patients had statistically similar pontine displacements to controls. Measured CSF pressure in patients pre- and post-lumbar puncture correlated significantly with pontine displacement (r = 0.49; P = .04).
CONCLUSIONS: This study establishes a relationship between pontine displacement from DENSE MR imaging and measured pressure obtained contemporaneously by lumbar puncture, providing a method to noninvasively assess intracranial pressure status in idiopathic intracranial hypertension.

PMID: 29284598 [PubMed - as supplied by publisher]

from Imaging via alkiviadis.1961 on Inoreader http://ift.tt/2CqnCGU

The impacts of the axial-to-radial airflow quantity ratio and suction distance on air curtain dust control in a fully mechanized coal face

Abstract

To understand the impacts of the axial-to-radial airflow quantity ratio (denoted as R) and the suction distance (denoted as D_s) on air curtain dust control in a fully mechanized coal face, the 3_down610 coal face in Jiangzhuang coal mine was numerically simulated in this study. A mathematic model was established to describe the airflow migration and dust diffusion in a coal face, and a scaled physical model was constructed. The comparison between simulation results and field measurements validated the model and the parameter settings. Furthermore, the airflow migration and dust diffusion at various R and D_s are analyzed using Ansys CFD. The results show that a reduction of R and D_s is conducive to the formation of an effective axial dust control air curtain; the dust diffusion distance decreases with the decrease of both R and D_s. By analyzing the simulation results, the optimal parameter for air curtain dust control in the 3_down610 coal face and those faces with similar production conditions is determined as R = 1/9 and D_s = 2 m. Under the optimal parameter condition, the high-concentration dust can be confined in front of the mining driver within a space 5.8 m away from the coal face.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2BX2xTq
via IFTTT