Evelyn Sklar

MRI of acute spinal epidural hematomas.

PURPOSE The purpose of this work was to determine the MR findings that characterize acute spinal epidural hematomas (ASEHs). METHOD The MR findings of 17 patients with ASEH (9 cervical, 7 thoracic, and 2 lumbar) were reviewed. Fifteen of the hematomas were secondary to trauma and two were spontaneous. Correlation with CT (8 cases) and surgical findings (11 cases) was also performed. RESULTS Imaging findings in ASEH were the following: (a) a variable signal intensity (on T1-weighted images, 10 showed isointensity to cord and 7 were slightly hyperintense; T2-weighted images showed hyperintensity with areas of hypointensity); (b) capping of epidural fat; (c) direct continuity with the adjacent osseous structures; (d) compression of epidural fat, subarachnoid sac, and spinal cord; (e) usually posterolateral location in the spinal canal. CONCLUSION Epidural hematomas in the spinal canal are lesions capable of producing sudden spinal cord and/or cauda equina compression. MR provides characteristic findings that allow a prompt diagnosis of acute epidural hematomas.

Optic neuropathy and chiasmopathy in the diagnosis of systemic lupus erythematosus.

Purpose To report the clinical presentation of acute visual loss in six patients who were ultimately diagnosed with systemic lupus erythematosus (SLE). Methods Retrospective case series. Results All patients had a positive antinuclear antibody and elevated anti–double stranded DNA titers. Five of six patients demonstrated gadolinium enhancement of the optic nerve and/or chiasm on magnetic resonance imaging (MRI). Most patients showed initial improvement after treatment with high-dose systemic corticosteroids, but five experienced recrudescences during steroid taper, requiring further treatment with immunosuppressive or cytotoxic medications. Conclusions Visual loss owing to optic neuropathy or chiasmopathy may be the presenting sign of SLE or the event that leads to this diagnosis. Gadolinium-enhanced MRI is useful for identifying anterior visual pathway lesions in these patients. Corticosteroids are effective in the treatment of this condition; however, relapses requiring further treatment are common.

Determination of cranio-spinal canal compliance distribution by MRI: Methodology and early application in idiopathic intracranial hypertension.

To develop a method for derivation of the cranial‐spinal compliance distribution, assess its reliability, and apply to obese female patients with a diagnosis of idiopathic intracranial hypertension (IIH).

Automated Quantitation of the Posterior Scleral Flattening and Optic Nerve Protrusion by MRI in Idiopathic Intracranial Hypertension

BACKGROUND AND PURPOSE: Subjective determination of the posterior sclera flattening and optic nerve protrusion in MRI is challenging because of the 3D nature of the globe morphology. This study aims to develop and compare quantitative measures of globe flattening and optic nerve protrusion with subjective rating, and assess relationships with papilledema grade and intraocular and CSF pressures. MATERIALS AND METHODS: Data of 34 globes from 7 overweight female patients with idiopathic intracranial hypertension and 6 age- and weight-matched healthy female control subjects were assessed, as well as a subcohort of 4 of the patients with idiopathic intracranial hypertension who underwent follow-up MR imaging 2 weeks after lumbar puncture and initiation of treatment with acetazolamide. MR imaging examination included a 3D CISS sequence on 1.5T and 3T scanners with 0.6-mm isotropic resolution. Subjective ratings of globe flattening were obtained by experienced and inexperienced readers. Quantitative measures of globe flattening, nerve protrusion, and maximal deformation were derived by use of a 2D map of the distances from the globe center to the posterior wall. RESULTS: Contingency coefficients for globe flattening agreements with subjective rating by the experienced and inexperienced readers were 0.72 and 0.56, respectively. Mean values of the 3 deformation measures were significantly poorer in the idiopathic intracranial hypertension group, with nerve protrusion demonstrating the strongest difference (P = .0002). Nerve protrusion was most strongly associated with papilledema grade with a contingency coefficient of 0.74 (P = .01), whereas globe flattening was negatively correlated with intraocular pressure (R = −0.75, P < .0001). Maximal deformation was negatively associated with CSF opening pressure (R = −0.86, P = .0001). After treatment, only the changes in nerve protrusion and maximal deformation were significant. CONCLUSIONS: Automated measures of globe deformation improve reliability over subjective rating. Of the 2 globe deformation measures, nerve protrusion had the strongest predictive value for papilledema grade and had the highest sensitivity for assessment of treatment efficacy in idiopathic intracranial hypertension.

Evidence for Altered Spinal Canal Compliance and Cerebral Venous Drainage in Untreated Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, is a debilitating neurological disorder characterized by elevated CSF pressure of unknown cause. IIH manifests as severe headaches, and visual impairments. Most typically, IIH prevails in overweight females of childbearing age and its incidence is rising in parallel with the obesity epidemic. The most accepted theory for the cause of IIH is reduced absorption of CSF due to elevated intracranial venous pressure. A comprehensive MRI study, which includes structural and physiological imaging, was applied to characterize morphological and physiological differences between a homogeneous cohort of female IIH patients and an age- and BMI-similar control group to further elucidate the underlying pathophysiology. A novel analysis of MRI measurements of blood and CSF flow to and from the cranial and spinal canal compartments employing lumped parameters modeling of the cranio-spinal biomechanics provided, for the first time, evidence for the involvement of the spinal canal compartment. The CSF space in the spinal canal is less confined by bony structures compared with the cranial CSF, thereby providing most of the craniospinal compliance. This study demonstrates that the contribution of spinal canal compliance in IIH is significantly reduced.

Evaluation of Magnetic Resonance Imaging Following Neuraxial Steroid Administration: Does Epidural Injection Produce Pathologic Findings?

Background and Objectives: Infection or hematoma following epidural anesthesia is a rare but potentially devastating complication unless diagnosed early. In order to diagnose spinal cord involvement, the currently recommended imaging test is magnetic resonance imaging (MRI). Despite this, no previous studies have been performed to define typical MRI findings following uneventful epidural injection. The purpose of this pilot study was to compare magnetic resonance images before and after epidural injection to define the characteristic appearance of MRI following an uneventful epidural steroid injection. Methods: Ten patients were prospectively enrolled and received an MRI study before and after an epidural injection of steroids plus local anesthetic for chronic low back pain using a loss of resistance to air technique. The magnetic resonance images were reviewed by 2 neuroradiologists who were blinded as to whether the scan was performed before or after the epidural injection. Results: Review of 20 MRI studies revealed no fluid collections, hematomas, or mass effect on the thecal sac. A needle track and a small amount of epidural air was seen in the majority of post‐epidural scans, but did not cause indentation of the thecal sac in any patient. None of the findings observed by the radiologists in the post‐epidural scans were considered clinically significant. Conclusions: The results of this pilot study demonstrated that after uneventful epidural injection in otherwise healthy patients, there were no new pathologic findings on MRI scans. Further MRI studies in large populations and in different clinical situations should be performed to confirm these preliminary findings.

Magnetic resonance imaging findings after uneventful continuous infusion neuraxial analgesia: a prospective study to determine whether epidural infusion produces pathologic magnetic resonance imaging findings.

BACKGROUND: Magnetic resonance imaging (MRI) is considered the preferred diagnostic tool to determine whether postepidural neurologic symptoms are due to hematoma or abscess. However, there is currently no published information regarding the normal appearance of a MRI after a continuous epidural infusion. In this prospective cohort study, we defined the characteristic appearance of MRI findings after uneventful epidural analgesia. METHODS: Thirty women were prospectively enrolled to undergo a lumbar MRI after labor and delivery. The study group consisted of 15 women who received neuraxial analgesia with a combined spinal epidural technique followed by continuous epidural infusion, whereas the control group included 15 women who delivered without receiving neuraxial analgesia. All patients received a MRI within 12 h of delivery via a 1.5T scanner. MRIs were reviewed by two neuroradiologists who were blinded to the patients study group allocation and asked to document the presence or absence of fluid collection, air collection, or soft tissue abnormalities. RESULTS: There were no radiologically significant fluid collections, hematomas, or mass effects noted on the thecal sac of any of the 30 MRI studies. A small amount of epidural air was seen in 77% of MRI studies after epidural analgesia, but there was no indention on the thecal sac. CONCLUSIONS: The lack of significant collections or mass effects seen in the MRIs of our patients after continuous infusion of epidural analgesia suggests that the presence of these findings in a patient with new neurologic symptoms after administration of epidural analgesia should be considered pathologic and warrant immediate attention.

Sacral Morel-Lavallée Lesion: A Not-So-Rare Diagnosis:

Morel-Lavallée lesions are closed soft tissue degloving injuries with a propensity to become infected, arising in the lumbosacral region or even the scalp, common anatomical locations in neuroradiological studies. The radiologist must recognize this entity, its traumatic etiology, and treatment options. Our patients Morel-Lavallée lesion was evaluated with ultrasound and MRI, demonstrating a predominantly hemorrhagic lesion successfully managed by aspiration.

Unusual Case of Cerebral Aspergillosis with Clinical and Imaging Findings Mimicking Lymphoma

A 14-year-old female post-transplant patient with a history of post-transplant lymphoproliferative disease/lymphoma presented with fever and lethargy. Computed tomography of the brain demonstrated a hypodense lesion with surrounding edema in the right periventricular region not seen on a routine study performed two weeks earlier. On magnetic resonance imaging (MRI) this lesion was mainly iso-intense to gray matter on T2-weighted (T2W) images and demonstrated peripheral contrast enhancement. Diffusion restriction was seen within most of the lesion including, but not limited to, its periphery. Lesion location and MRI characteristics, particularly on T2W and diffusion sequences, were suggestive of lymphoma. The patients history of post-transplant lymphoproliferative disorder also supported this diagnosis. However, in view of the patients immunocompromised state, rapid onset of symptoms, and recent normal CT scan of the brain, infection was also entertained. Biopsy revealed short branching hyphae consistent with aspergillosis. This case is interesting as the MRI restriction pattern and the patients history were more suggestive of lymphoma, but in reality the lesion represented an evolving aspergillosis abscess. Biopsy was necessary to further proceed with appropriate medical management, which is significantly different for the two entities.

Infectious Diseases of the Spine and Spinal Cord

The wide variety of presentations together with improvements in imaging techniques make this area one of the most exciting topies in neuroimaging.