Sciatic nerve sarcoidosis: utility of magnetic resonance peripheral nerve imaging and treatment with radiation therapy

2004 ◽  
Vol 100 (5) ◽  
pp. 956-959 ◽  
Author(s):  
Andrew T. Dailey ◽  
Matthew T. Rondina ◽  
Jeannette J. Townsend ◽  
Dennis C. Shrieve ◽  
J. Richard Baringer ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Magnetic Resonance ◽  
Sciatic Nerve ◽  
Mr Imaging ◽  
Peripheral Nerve ◽  
Foot Drop ◽  
Content Type ◽  
Nerve Imaging ◽  
Noncaseating Granulomas ◽  
Peripheral Nerve Imaging

✓ Sarcoidosis may involve both the central and peripheral nervous system, although peripheral nerve manifestations are usually seen late in the disease. In this report, the authors describe a case of sarcoidosis in a 22-year-old woman who presented with a foot drop. Although results of conventional lumbar magnetic resonance (MR) imaging were normal, MR peripheral nerve imaging of the thigh showed a mass in the sciatic nerve indicating tumor. An intraoperative biopsy sample revealed noncaseating granulomas consistent with sarcoid. The patient was treated with steroid drugs to control the manifestations of her disease but exhibited early signs of femoral bone necrosis, which required discontinuation of the steroids. She was then treated with local radiation therapy. At her 2-year follow-up visit the patient demonstrated relief of her symptoms and improvement on MR peripheral nerve imaging. This case demonstrates that sarcoidosis may present with peripheral nerve manifestations. The appearance of a diffusely swollen nerve on MR imaging should prompt clinicians to include sarcoidosis in the differential diagnosis and plan surgery accordingly. Patients who are not responsive to or who are unable to tolerate medical therapy may be treated with radiation therapy.

In vivo targeted peripheral nerve imaging with a nerve-specific nanoscale magnetic resonance probe

2014 ◽  
Vol 83 (5) ◽  
pp. 588-592 ◽  
Author(s):  
Linfeng Zheng ◽  
Kangan Li ◽  
Yuedong Han ◽  
Wei Wei ◽  
Sujuan Zheng ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Peripheral Nerve ◽  
Nerve Imaging ◽  
Peripheral Nerve Imaging

Hand and Wrist Neuropathies: High-resolution Ultrasonography and MR Neurography

2021 ◽  
Vol 25 (02) ◽  
pp. 366-378
Author(s):  
Avneesh Chhabra ◽  
Raghu Ratakonda ◽  
Federico Zaottini ◽  
Riccardo Picasso ◽  
Carlo Martinoli
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Nerve Imaging ◽  
High Resolution Ultrasonography ◽  
Peripheral Nerve Imaging ◽  
Technical Considerations

AbstractHigh-resolution ultrasonography (US) and magnetic resonance neurography (MRN) have followed parallel paths for peripheral nerve imaging with little comparison of the two modalities. They seem equally effective to study a variety of neuropathies affecting large and small nerves in the wrist and hand. This article outlines the technical considerations of US and MRN and discusses normal and abnormal imaging appearances of hand and wrist nerves from etiologies such as entrapment, injury, tumor, and proximal and diffuse neuropathy, with specific case illustrations.

Magnetic resonance neurography of peripheral nerve following experimental crush injury, and correlation with functional deficit

2002 ◽  
Vol 96 (4) ◽  
pp. 755-759 ◽  
Author(s):  
Simon A. Cudlip ◽  
Franklyn A. Howe ◽  
John R. Griffiths ◽  
B. Anthony Bell
Keyword(s):  
Magnetic Resonance ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Nerve Crush ◽  
Content Type ◽  
Functional Deficit ◽  
Track Analysis ◽  
Fine Print

Object. In a number of clinical studies magnetic resonance (MR) neurography has been used to examine patients with peripheral nerve damage, but little is understood about the sequence of imaging changes following nerve injuries, and how they correlate with functional deficit. The goal of this study was to further understanding of these changes and their implications. Methods. Using the rat sciatic nerve crush model, the sciatic nerve was imaged at intervals over 70 days in 12 rats. Sham-operated contralateral nerves served as controls. A 4.7-tesla MR imager with a custom-made surface coil was used. The T2 maps were calculated from images obtained at four echo times and from regions of interest designated on the nerve at three sites. Walking-track analysis was performed at the same intervals as imaging. Magnetic resonance neurography revealed a mean T2 of normal sciatic nerve of 36 msec (standard deviation [SD] 1.2 msec). Crushed nerves demonstrated a sequence of changes in signal intensity that were maximal at 14 days, with a mean T2 of 64 msec (SD 5.2 msec), then falling to a T2 of 53 msec (SD 3.7 msec). Sham-operated nerves had a short and nonsustained rise in signal at 7 days. Walking-track analysis revealed maximum deficit immediately postinjury, with an improvement in function approaching that of control nerves at 30 days. Conclusions. In this study the authors demonstrate that quantitative assessment of nerve signals with MR neurography allows the sequence of events following nerve crush injury to be followed in vivo, and that a return toward a normal signal correlates with functional improvement. Assessment of peripheral nerve injury in patients by using MR neurography has the potential to confirm acute nerve injury as well as to monitor the recovery process.

Radiation therapy for juvenile pilocytic astrocytoma of the pituitary stalk

1992 ◽  
Vol 77 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Juji Takeuchi ◽  
Kiyoshi Kikuchi ◽  
Yuta Shibamoto ◽  
Ichiro Fujisawa
Keyword(s):  
Radiation Therapy ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Growth Retardation ◽  
Pilocytic Astrocytoma ◽  
Residual Tumor ◽  
Pituitary Stalk ◽  
Content Type ◽  
Juvenile Pilocytic Astrocytoma ◽  
Fine Print

✓ A case of juvenile pilocytic astrocytoma of the pituitary stalk is reported. The patient presented with diabetes insipidus and growth retardation. Magnetic resonance (MR) imaging was useful in diagnosing the lesion. Although the tumor could not be completely removed by surgery, radiotherapy was effective and the residual tumor disappeared 6 months after irradiation. The patient's condition has remained stable and no recurrence has been observed by MR imaging in the 4 years since radiation therapy.

Magnetic resonance imaging—guided percutaneous fenestration of a cervical intradural cyst

2003 ◽  
Vol 99 (3) ◽  
pp. 313-315 ◽  
Author(s):  
Shinobu Takahashi ◽  
Shigehiro Morikawa ◽  
Masaaki Egawa ◽  
Yasuo Saruhashi ◽  
Yoshitaka Matsusue
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Complete Disappearance ◽  
Resonance Imaging ◽  
Content Type ◽  
Local Anesthetic Agent ◽  
Intradural Extramedullary ◽  
Severe Exercise ◽  
Exercise Induced ◽  
High Cervical

✓ The authors describe the case of a high cervical, intradural extramedullary cyst located anterior to the spinal cord in a 13-year-old boy. The lesion was fenestrated percutaneously by using real-time magnetic resonance (MR) imaging guidance and a local anesthetic agent. The patient's symptom, severe exercise-induced headache, immediately resolved after treatment. Nine months later, complete disappearance of the cyst was confirmed on MR imaging and computerized tomography myelography. Magnetic resonance imageing—guided fenestration can be considered a minimally invasive option for intradural cystic lesions.

Early changes measured by magnetic resonance imaging in cerebral blood flow, blood volume, and blood-brain barrier permeability following dexamethasone treatment in patients with brain tumors

1999 ◽  
Vol 90 (2) ◽  
pp. 300-305 ◽  
Author(s):  
Leif Østergaard ◽  
Fred H. Hochberg ◽  
James D. Rabinov ◽  
A. Gregory Sorensen ◽  
Michael Lev ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Clinical Effects ◽  
Content Type ◽  
Fine Print

Object. In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral blood volume (CBV) or blood-tumor barrier (BTB) permeability and thereby the degree of vasogenic edema.Methods. Using magnetic resonance (MR) imaging, the authors examined the acute changes in CBV, cerebral blood flow (CBF), and BTB permeability to gadolinium-diethylenetriamine pentaacetic acid after administration of dexamethasone in six patients with brain tumors. In patients with acute decreases in BTB permeability after dexamethasone administration, changes in the degree of edema were assessed using the apparent diffusion coefficient of water.Conclusions. Dexamethasone was found to cause a dramatic decrease in BTB permeability and regional CBV but no significant changes in CBF or the degree of edema. The authors found that MR imaging provides a powerful tool for investigating the pathophysiological changes associated with the clinical effects of glucocorticoids.

Accelerated spondylotic changes adjacent to the fused segment following central cervical corpectomy: magnetic resonance imaging study evidence

2004 ◽  
Vol 100 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Vaijayantee Kulkarni ◽  
Vedantam Rajshekhar ◽  
Lakshminarayan Raghuram
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Imaging Study ◽  
Degenerative Changes ◽  
Adjacent Segment ◽  
Mr Images ◽  
Short Term ◽  
Content Type ◽  
Fine Print

Object. The authors studied whether cervical spine motion segments adjacent to a fused segment exhibit accelerated degenerative changes on short-term follow-up magnetic resonance (MR) imaging. Methods. Preoperative and short-term follow-up (mean duration 17.5 months, range 10–48 months) cervical MR images obtained in 44 patients who had undergone one- or two-level corpectomy for cervical spondylotic myelopathy were evaluated qualitatively and quantitatively. The motion segment adjacent to the fused segment and a segment remote from the fused segment were evaluated for indentation of the thecal sac, disc height, and sagittal functional diameter of the spinal canal on midsagittal T2-weighted MR images. Thecal sac indentations were classifed as mild, moderate, and severe. New indentations of the thecal sac of varying severity (mild in 17 patients [38.6%], moderate in 10 [22.7%], and severe in six [13.6%]) had developed at the adjacent segments in 33 (75%) of 44 patients. The degenerative changes were seen at the superior level in 11 patients, inferior level in 10 patients, and at both levels in 12 patients and resulted from both anterior and posterior element degeneration in the majority (23 [69.6%]) of patients. The remote segments showed mild thecal sac indentations in seven patients and moderate indentations in two patients (nine [20.5%] of 44). Compared with the changes at the remote segment, the canal size was significantly decreased at the superior adjacent segment by 0.9 mm (p = 0.007). No patient sustained a new neurological deficit due to adjacent-segment changes. Conclusions. On short-term follow-up MR imaging, levels adjacent to the fused segment exhibited more pronounced degenerative changes (compared with remote levels) in 75% of patients who had undergone one- or two-level central corpectomy.

Lack of agreement between direct magnetic resonance imaging and statistical determination of a subthalamic target: the role of electrophysiological guidance

2002 ◽  
Vol 97 (3) ◽  
pp. 591-597 ◽  
Author(s):  
Emmanuel Cuny ◽  
Dominique Guehl ◽  
Pierre Burbaud ◽  
Christian Gross ◽  
Vincent Dousset ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Functional Response ◽  
Anterior Commissure ◽  
Surgical Techniques ◽  
High Frequency Stimulation ◽  
Mr Images ◽  
Posterior Commissure ◽  
Content Type ◽  
Fine Print

Object. The goal of this study was to determine the most suitable procedure(s) to localize the optimal site for high-frequency stimulation of the subthalamic nucleus (STN) for the treatment of advanced Parkinson disease. Methods. Stereotactic coordinates of the STN were determined in 14 patients by using three different methods: direct identification of the STN on coronal and axial T2-weighted magnetic resonance (MR) images and indirect targeting in which the STN coordinates are referred to the anterior commissure—posterior commissure (AC—PC) line, which, itself, is determined either by using stereotactic ventriculography or reconstruction from three-dimensional (3D) MR images. During the surgical procedure, electrode implantation was guided by single-unit microrecordings on multiple parallel trajectories and by clinical assessment of stimulations. The site where the optimal functional response was obtained was considered to be the best target. Computerized tomography scanning was performed 3 days later and the scans were combined with preoperative 3D MR images to transfer the position of the best target to the same system of stereotactic coordinates. An algorithm was designed to convert individual stereotactic coordinates into an all-purpose PC-referenced system for comparing the respective accuracy of each method of targeting, according to the position of the best target. Conclusions. The target that is directly identified by MR imaging is more remote (mainly in the lateral axis) from the site of the optimal functional response than targets obtained using other procedures, and the variability of this method in the lateral and superoinferior axes is greater. In contrast, the target defined by 3D MR imaging is closest to the target of optimal functional response and the variability of this method is the least great. Thus, 3D reconstruction adjusted to the AC—PC line is the most accurate technique for STN targeting, whereas direct visualization of the STN on MR images is the least effective. Electrophysiological guidance makes it possible to correct the inherent inaccuracy of the imaging and surgical techniques and is not designed to modify the initial targeting.

Physiological support and monitoring of critically ill patients during magnetic resonance imaging

1988 ◽  
Vol 68 (2) ◽  
pp. 246-250 ◽  
Author(s):  
Gene H. Barnett ◽  
Allan H. Ropper ◽  
Keith A. Johnson
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Critically Ill ◽  
Resonance Imaging ◽  
Monitoring Equipment ◽  
Mr Image ◽  
Content Type ◽  
Neurological Patients ◽  
Fine Print ◽  
Electrical Interference

✓ Magnetic resonance (MR) imaging has been largely restricted to patients who are neurologically and hemodynamically stable. The strong magnetic field and radiofrequency transmissions involved in acquiring images are potential sources of interference with monitoring equipment. A method of support and physiological monitoring of critically ill neurosurgical and neurological patients during MR imaging using a 0.6-tesla MR system is reported. This technique has not caused degradation of the MR image due to electrical interference. Adequate preparation and precautions allow many critically ill neurosurgical and neurological patients to safely undergo MR imaging.

Sign in / Sign up

Export Citation Format

Share Document