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OBJECTIVE Chiari malformation type 1 (CM-1) and spontaneous intracranial hypotension (SIH) are causes of headache in which cerebellar tonsillar ectopia (TE) may be present. An accurate method for differentiating these conditions on imaging is needed to avoid diagnostic confusion. Here, the authors sought to determine whether objective measurements of midbrain morphology could distinguish CM-1 from SIH on brain MRI. METHODS This is a retrospective case-control series comparing neuroimaging in consecutive adult subjects with CM-1 and SIH. Measurements obtained from brain MRI included previously reported measures of brain sagging: TE, slope of the third ventricular floor (3VF), pontomesencephalic angle (PMA), mamillopontine distance, lateral ventricular angle, internal cerebral vein–vein of Galen angle, and displacement of iter (DOI). Clivus length (CL), an indicator of posterior fossa size, was also measured. Measurements for the CM-1 group were compared to those for the entire SIH population (SIHall) as well as a subgroup of SIH patients with > 5 mm of TE (SIHTE subgroup). RESULTS Highly significant differences were observed between SIHall and CM-1 groups in the following measures: TE (mean ± standard deviation, 3.1 ± 5.7 vs 9.3 ± 3.5 mm), 3VF (−16.8° ± 11.2° vs −2.1° ± 4.6°), PMA (44.8° ± 13.1° vs 62.7° ± 9.8°), DOI (0.2 ± 4.1 vs 3.8 ± 1.6 mm), and CL (38.3 ± 4.5 vs 44.0 ± 3.3 mm; all p < 0.0001). Eight (16%) of 50 SIH subjects had TE > 5 mm; in this subgroup (SIHTE), a cutoff value of < −15° for 3VF and < 45° for PMA perfectly discriminated SIH from CM-1 (sensitivity and specificity = 1.0). DOI showed perfect specificity (1.0) in detecting SIH among both groups. No subjects with SIH had isolated TE without other concurrent findings of midbrain sagging. CONCLUSIONS Measures of midbrain sagging, including cutoff values for 3VF and PMA, discriminate CM-1 from SIH and may help to prevent misdiagnosis and unnecessary surgery.

CSF-venous fistulas (CVFs), first described in 2014, are an important cause of spontaneous intracranial hypotension. CVFs can be challenging to detect on conventional anatomic imaging because, unlike other types of spinal CSF leak, they do not typically result in pooling of fluid in the epidural space, and imaging signs of CVF may be subtle. Specialized myelographic techniques have been developed to help with CVF identification, but these techniques are not yet widely disseminated. This article reviews the current understanding of CVFs, emphasizing correlations between venous anatomy and imaging findings as well as potential mechanisms for pathogenesis, and describes current imaging techniques used for CVF diagnosis and localization. These techniques are broadly classified into fluoroscopy-based methods, including digital subtraction myelography and dynamic myelography, and cross-sectional methods, including decubitus CT myelography and MR myelography with intrathecal injection of gadolinium. Knowledge of these various options, including their relative advantages and disadvantages, is critical in the care of patients with spontaneous intracranial hypotension. Investigation is ongoing, and continued advances in knowledge about CVFs as well as in optimal imaging detection are anticipated.

Endogenous apolipoprotein (apo) E mediates neuroinflammatory responses and recovery after brain injury. Exogenously administered apoE-mimetic peptides effectively penetrate the central nervous system compartment and downregulate acute inflammation. CN-105 is a novel apoE-mimetic pentapeptide with excellent evidence of functional and histological improvement in preclinical models of intracerebral hemorrhage (ICH). The CN-105 in participants with Acute supraTentorial intraCerebral Hemorrhage (CATCH) trial is a first-in-disease-state multicenter open-label trial evaluating safety and feasability of CN-105 administration in patients with acute primary supratentorial ICH. Eligible patients were aged 30–80 years, had confirmed primary supratentorial ICH, and were able to intiate CN-105 administration (1.0 mg/kg every 6 h for 72 h) within 12 h of symptom onset. A priori defined safety end points, including hematoma volume, pharmacokinetics, and 30-day neurological outcomes, were analyzed. For clinical outcomes, CATCH participants were compared 1:1 with a closely matched contemporary ICH cohort through random selection. Hematoma volumes determined from computed tomography images on days 0, 1, 2, and 5 and ordinal modified Rankin Scale score at 30 days after ICH were compared. In 38 participants enrolled across six study sites in the United States, adverse events occurred at an expected rate without increase in hematoma expansion or neurological deterioration. CN-105 treatment had an odds ratio (95% confidence interval) of 2.69 (1.31–5.51) for lower 30-day modified Rankin Scale score, after adjustment for ICH score, sex, and race/ethnicity, as compared with a matched contemporary cohort. CN-105 administration represents an excellent translational candidate for treatment of acute ICH because of its safety, dosing feasibility, favorable pharmacokinetics, and possible improvement in neurological recovery.

Spontaneous intracranial hypotension (SIH) is a clinical syndrome that is increasingly recognized as an important and treatable secondary cause of headaches. Insight into the condition has evolved significantly over the past decade, resulting in a greater understanding of the underlying pathophysiology, development of new diagnostic imaging tools, and a broadening array of targeted treatment options. This article reviews the clinical presentation and pathogenesis of SIH, discusses the important role of imaging in diagnosis, and describes how imaging guides treatment.

BACKGROUND: Previous studies analyzed contrast agent spread during cervical interlaminar epidural steroid injections (CILESIs) by using planar fluoroscopy and reported wide variance of the rate of spread to the ventral epidural space (VES). Cross-sectional CT allows for direct viewing of contrast agent in the VES, providing improved spread assessment and thereby informing needle placement decisions when targeting pain generators. PURPOSE: To determine the extent of injectate spread at CT fluoroscopy–guided CILESI, with particular attention to the VES and bilateral neuroforamina, by using cross-sectional CT. MATERIALS AND METHODS: This study reviewed 83 consecutive CT fluoroscopy–guided CILESIs at which a postprocedural cervical spine CT was performed (June 2016 to December 2017). All procedures used the same injectate (2 mL corticosteroid, 3 mL contrast agent). Postprocedural CT scans were reviewed for the presence of contrast within the VES, dorsal epidural space, ipsilateral neuroforamen, and contralateral neuroforamen in every cervical interlaminar level. Descriptive data are presented as frequencies or means. McNemar tests or hierarchical logistic models were used to assess associations between covariates and contrast agent spread to particular locations. RESULTS: The study cohort included 73 individual patients (59% women; 43 of 73) (mean patient age, 57.6 years ± 11.5 [standard deviation]). Mean number of levels of cranial spread were 0.6 level for VES, 1.9 levels for contralateral neuroforamen, 2.1 levels for ipsilateral neuroforamen, and 3 levels for dorsal epidural space. No VES spread in any level was found with 35% (29 of 83) of injections. VES spread was more likely to occur in the level of needle placement (43%; 36 of 83) than in other interlaminar levels (19.5%; 97 of 498; P < .001). Spread was more likely to occur in the neuroforamen ipsilateral to the needle approach compared with contralateral (P < .001). CONCLUSION: Cervical interlaminar epidural steroid injections have injectate spreads with a mean of less than one level cranially in the ventral epidural space (VES) and approximately two levels in the neuroforamen. VES spread occurs more frequently at the level of needle placement and within the ipsilateral neuroforamen. © RSNA, 2019

This review discusses cerebral venous thrombosis (CVT), including diagnosis and treatment strategies, a rare class of stroke that, if unrecognized or untreated, can have devastating effects. Thrombosis of one or many cerebral veins leads to propagation of thrombosis and impaired cerebral venous drainage. Diagnosis is made using a combination of history and imaging, particularly computed tomography (CT) venogram, which demonstrates thrombosis. Currently, acute treatment consists of heparin infusion with transition to long-term oral anticoagulation. Further research, especially on prevention, endovascular therapy, and the role of newer anticoagulants (direct oral anticoagulants [DOACs]) is necessary and ongoing.

Myelopathy refers to any pathologic process that involves the spinal cord, and can be caused by a variety of different diseases. MR imaging is the primary modality for evaluating the patient presenting with myelopathy. The first step must be the exclusion of spinal cord compression. Although the MR features of many causes of myelopathy overlap, careful attention to the time course of presentation, knowledge of common and uncommon causes of myelopathy, and identification of specific imaging patterns and features can help narrow the differential diagnosis or establish a definitive diagnosis.

Spontaneous intracranial hypotension (SIH) is a condition that has become increasingly recognized, necessitating more widespread familiarity with diagnosis and management. This chapter reviews the clinical presentation, pathogenesis, approach to brain and spinal imaging, and use of image-guided intervention for treatment of SIH. Specialized imaging techniques for problem-solving difficult cases are discussed, and procedural details of how to perform epidural patching are provided.

BackgroundEndogenous apoliloprotein E mediates neuroinflammatory responses and recovery after brain injury. Exogenously administered apolipoprotein E-mimetic peptides can effectively penetrate the brain and down-regulate acute inflammation. CN-105 is a novel apolipoprotein E-mimetic pentapeptide with excellent preclinical evidence as an acute intracerebral hemorrhage (ICH) therapeutic. TheCN-105 in participants withAcute supraTentorial intraCerebralHemorrhage (CATCH) trial is a first-in-disease-state, multi-center, open-label trial evaluating safety and feasability of CN-105 administration in patients with acute primary supratentorial ICH.MethodsEligible patients were age 30-80 years, had confirmed primary supratentorial ICH, and able to intiate CN-105 administration (1.0 mg/kg every 6 hours for 72 hours) within 12 hours of symptom onset.A prioridefined safety endpoints, including hematoma volume, pharmacokinetics, and 30-day neurological outcomes were analyzed. For comparisons, CATCH participants were matched 1:1 with a contemporary ICH cohort through random selection. Hematoma volumes determined from computed tomography images on Days 0, 1, 2, and 5 and ordinal modified Rankin Score at 30 days after ICH were compared.ResultsIn 39 participants enrolled across six study sites in the United States, adverse events occurred at expected rate without increase in hematoma expansion or neurological deterioration or significant serum accumulation. CN-105 treatment had an odds ratio (95% confidence interval) of 2.69 (1.31–5.51) for lower 30-day mRS, after adjustment for ICH Score, sex, and race/ethnicity, compared to matched contemporary cohort.ConclusionCN-105 administration represents an excellent translational candidate as an actue ICH therapeutic due to its safety, dosing feasibility, favorable pharmacokinetics, and evidence of improved neurological recovery.

The objective of this study is to determine the rate of inadvertent dural puncture during CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injection. In addition, in a subanalysis, we aim to assess the rate of inadvertent dural puncture superior to C5-C6 occurring during interlaminar epidural corticosteroid injection using CT fluoroscopy guidance because such injections are not performed using conventional fluoroscopy.Images obtained from consecutive CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injections conducted from November 2009 to November 2015 were reviewed. The following information was recorded: the presence of inadvertent dural puncture, the level of the cervical interlaminar space, approach laterality (left or right), anteroposterior spinal canal diameter, and the presence of a trainee. Two-tailed Fisher exact tests were used for assessment of categoric variables, and t tests were used for continuous variables.A total of 974 cervical interlaminar epidural corticosteroid injections were identified in 728 patients. Inadvertent dural punctures were identified in association with 1.4% (14/974) of these injections; all punctures were recognized during the procedure. Needle placements were performed at every cervical level (C1-C2 through C7-T1). The highest rate of dural puncture (2.8%) occurred at C5-C6. No dural punctures occurred superior to C5-C6 (16.6% of cases). The complication rate was 0.4%. Only greater anteroposterior spinal canal diameter was associated with increased dural puncture rates (p = 0.049).CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injections were performed at all levels throughout the cervical spine. A very low complication rate and a minimal rate of inadvertent dural puncture were noted, similar to previously reported rates for conventional fluoroscopy-guided injections limited to the lower cervical spine only.

The objective of our study was to determine whether the presence of individual imaging signs of spontaneous intracranial hypotension (SIH) is correlated with increasing duration of headache symptoms. Of particular interest is the relationship of symptom duration to dural enhancement because it is the most commonly identified imaging sign in patients with SIH.Eighty-nine patients with SIH who underwent pretreatment brain MRI and total-spine CT myelography and whose medical record included data on the duration of clinical symptoms were included in this cross-sectional retrospective study. Brain imaging was reviewed for the presence of dural enhancement, brain sagging, and the "venous distention" sign. CT myelograms were assessed for CSF leak. If present, a leak was subcategorized as a high-flow or low-flow leak. Differences in headache duration between subjects with and those without individual imaging signs were compared.Subjects without dural enhancement on brain MRI had a longer average duration of symptoms than those with dural enhancement present (average symptom duration: 45.3 ± 59.0 [SD] vs 15.1 ± 33.0 weeks, respectively; p = 0.002). No difference in symptom duration was observed between subjects whose MRI studies showed and those whose MRI studies did not show brain sagging (p = 0.10) or the venous distention sign (p = 0.21). The presence of a CSF leak on CT myelography was not associated with symptom duration (p = 0.56) except in the subgroup of patients with low-flow leaks.Increasing symptom duration in SIH is associated with decreased prevalence of abnormal dural enhancement on brain MRI. Because dural enhancement is considered a hallmark imaging feature of this condition, its absence may exacerbate the problem of underdiagnosis in chronic cases of SIH.

Objectives Spontaneous intracranial hypotension (SIH) is a pathologic state of low CSF volume caused by a CSF to venous fistula or CSF leak. It is diagnosed based on symptoms, imaging, and CSF pressure but is often a diagnostic challenge because no single test is highly sensitive. Physician-induced changes in CSF volume may result in changes in patient symptoms, as has been shown with idiopathic intracranial hypertension (IIH). The purpose of this study is to determine the sensitivity of CSF volume provocation maneuvers in the diagnosis of SIH. Patients and Methods We reviewed consecutive patients that underwent lumbar puncture from January 2015 to January 2017. Patients were included if they met ICHD3 criteria for SIH and CSF volume provocation maneuvers were performed. Cases were considered concordant if there was improvement of symptoms with addition of CSF. Results 1084 patients underwent 2250 CT-guided lumbar punctures from January 2015 to January 2017. 92 patients with SIH were identified and 62 of these patients underwent CSF volume provocation maneuvers. 58% (36/62) had concordant lumbar puncture encounters with symptom improvement upon addition of artificial CSF. Conclusion CSF volume provocation maneuvers demonstrate 58% sensitivity for identifying patients with SIH, better than those reported for CSF opening pressure and myelography. A positive symptomatic response to CSF volume provocation maneuvers was independent of the other objective tests used for SIH and may aid in the often-challenging diagnostic workup of these patients. Future prospective case-controlled studies are needed.

Spontaneous intracranial hypotension is caused by spinal CSF leaks, but the site of the leak is not always detected on spinal imaging. We report on the additional value of decubitus positioning during CT myelography in enhancing the detection of subtle leaks.

BACKGROUND AND PURPOSE: Inadvertent intrafacet injection can occur during interlaminar epidural steroid injection, resulting in a false-positive loss of resistance and nontarget injection of medication. The purpose of this investigation was to compare the observed rates of this phenomenon during lumbar interlaminar epidural steroid injection performed by using conventional fluoroscopic and CT fluoroscopic guidance. MATERIALS AND METHODS: We retrospectively reviewed 349 lumbar interlaminar epidural steroid injections performed by using conventional fluoroscopy or CT fluoroscopic guidance to determine the observed rates of inadvertent intrafacet injection with each technique. Cases of inadvertent intrafacet injection were classified as either recognized or unrecognized by the proceduralist at the time of the procedure. Multivariate logistic regression was used to determine the independent effect of imaging guidance technique, age, and sex. RESULTS: The rate of inadvertent intrafacet injection was observed to be 7.5% in the CT fluoroscopic group and 0.75% in the conventional fluoroscopy group. All 16 cases identified from CT fluoroscopic procedures were recognized during the procedure; the single case identified from conventional fluoroscopy procedures was not recognized prospectively. The type of imaging guidance showed a statistically significant effect on the detection of the phenomenon (OR for conventional fluoroscopy versus CT fluoroscopy = 0.10, P = .03) that was independent of differences in age or sex. CONCLUSIONS: Inadvertent intrafacet injection is identified during CT fluoroscopic–guided interlaminar epidural steroid injection at a rate that is 10-fold greater than the same procedure performed under conventional fluoroscopy guidance.

OBJECTIVE. The purpose of this study is to describe the procedure for CT fluoroscopy–guided lumbar medial branch blocks and facet radiofrequency ablation. CONCLUSION. CT fluoroscopic guidance allows more-precise needle tip positioning and is an alternative method for performing medial branch blocks and facet radiofrequency ablation.

BACKGROUND AND PURPOSE: Epidural blood patch treatment of spontaneous intracranial hypotension arising from ventral CSF leaks can be difficult secondary to challenges in achieving ventral spread of patching material. The purpose of this study was to determine the technical success rates and safety profile of direct needle placement into the ventral epidural space via a posterior transforaminal approach. MATERIALS AND METHODS: We retrospectively reviewed consecutive CT fluoroscopy–guided epidural blood patches from June 2013 through July 2015. Cases were included if a posterior transforaminal approach was taken to place the needle directly in the ventral epidural space. Rates of technical success (defined as contrast in the spinal canal ventral epidural space) and optimal epidurogram (defined as contrast spreading into or beyond the middle third of the spinal canal ventral epidural space) were determined. Factors influencing these rates were assessed. All complications, inadvertent intravascular injections, and intrathecal punctures were recorded. RESULTS: A total of 72 ventral epidural blood patches were identified; immediate technical success was achieved in 95.8% and an optimal epidurogram in 47.2%. Needle position within the spinal canal ventral epidural space was associated with obtaining an optimal epidurogram (P = .005). Inadvertent intravascular injection was identified in 29.3% of cases, but all were venous. There were no inadvertent intrathecal punctures or complications. CONCLUSIONS: Direct needle placement in the ventral epidural space via a transforaminal approach for treatment of ventral CSF leaks has an excellent technical success rate and safety profile. This technique can be considered as a treatment option in selected patients with ventral CSF leaks for whom traditional techniques are unsuccessful.

Received September 14, 2015; revised November 5, 2015; accepted November 5, 2015. From Department of Internal Medicine and Psychiatry, Duke University, Durham, NC (JF, XP); Department of Neurology, Duke University, Durham, NC (CL, GB); Department of Neuroradiology, Duke University, Durham, NC (PGK). Send correspondence and reprint requests to Jacob Feigal, M.D., Departments of Internal Medicine and Psychiatry, Duke University Hospital, 2301 Erwin Rd, Durham, NC 27707; e-mail: jacob.feigal@duke.edu & 2016TheAcademy of PsychosomaticMedicine. Published by Elsevier Inc. All rights reserved. Introduction

CT fluoroscopy-guided lumbar spine pain injections typically include a preprocedural planning CT that contributes considerably to patient dose. The purpose of this study was to quantify the degree of radiation exposure reduction achieved by modifying only the planning CT component of the examination.A retrospective review was performed of 80 CT fluoroscopy-guided lumbar spine injections. Forty patients were scanned with a standard protocol using automatic tube current modulation (method A). Another 40 patients were scanned using a new technique that fixed the tube current of the planning CT to either 50 or 100 mA on the basis of the patient's anteroposterior diameter and that reduced the z-axis coverage (method B). Dose-length products (DLPs) were compared for the two methods.The mean maximal tube current for the planning CT was 435.0 mA for method A and 67.5 mA for method B. The mean z-axis was shorter for method B at 6.5 cm than for method A at 9.6 cm (p0.0001). The mean DLP for the planning CT was 11 times lower for method B than for method A: 27.9 versus 313.1 mGy × cm, respectively (p0.0001). When method B was used, the mean DLP for the total procedure (i.e., planning CT plus CT fluoroscopy components) was reduced by 78%. There was no significant difference between methods A and B in CT fluoroscopy time (p = 0.37). All procedures were technically successful.A nearly fivefold reduction in radiation exposure can be achieved in CT fluoroscopy-guided lumbar spine pain injections through modifications to the planning CT alone.

Spontaneous intracranial hemorrhage is a commonly encountered neurologic emergency. Imaging plays important roles in both guiding the emergent stabilization of patients with ICH and in elucidating the etiology of the hemorrhage to prevent rebleeding. A thorough understanding of the factors that have an impact on immediate management, the causes of hemorrhage, and the strengths of various imaging techniques in addressing these 2 concerns is vital to crafting a patient-centered approach to this condition.

The purpose of this study was to assess the rate of inadvertent injection into the retrodural space of Okada during CT fluoroscopy-guided interlaminar epidural steroid injection in the cervical spine.Images from cases of cervical interlaminar epidural steroid injection under CT fluoroscopic guidance performed at a single institution between November 2009 and November 2015 were obtained and reviewed. For all cases, the following information was recorded: presence or absence of contrast material within the Okada space, cervical anatomic level at which the procedure was performed, laterality of approach, trainee presence, and years of proceduralist experience. Two-tailed chi-square tests were used to assess categoric variables, and t tests were performed to assess for continuous variables predictive of nontarget injection.A total of 974 CT fluoroscopy-guided cervical interlaminar epidural steroid injections were identified in 728 patients. The presence of contrast material in the retrodural space of Okada was identified in 2.9% of cases (28/974). All cases of inadvertent injection were identified and corrected intraprocedurally. The greatest rate of inadvertent injection (4.6% [18/389]) occurred at C5-6. No variables predictive of inadvertent injection into the Okada space were identified. There was a 0.4% (4/974) complication rate, and all complications were minor.We identified a 2.9% rate of unintended injection into the retrodural space of Okada during cervical interlaminar epidural steroid injection. If unrecognized, these nontarget injections can result in treatment failure in a subset of patients who undergo cervical interlaminar epidural steroid injection. Future study is warranted to assess the rate of inadvertent Okada injection under conventional fluoroscopy and to compare the rates of detection between the two imaging-guided modalities.

Decisions to limit care, including use of a do-not-resuscitate (DNR) order, are associated with increased risk of death after intracerebral hemorrhage (ICH). Given the value that patient surrogates place on the physician's perception of prognosis, understanding prognostic indicators that influence clinical judgment of outcomes is critical.The purpose of this study was to understand the patient variables and comorbid illnesses associated with DNR orders placed on patients within 72 hours after ICH.Single-center, retrospective review of medical records of 198 consecutive patients with an admission diagnosis of primary supratentorial ICH between July 2007 and December 2010.Patients who did not experience a DNR order placement during their primary admission for ICH (non-DNR group) were compared to patients who received a new DNR order in the first 72 hours of admission (DNR group).Patient characteristics obtained include demographic data, past medical history, clinical data pertaining to the admission for the ICH, and radiographic images. Demographic, medical, and ICH injury data during the first three days of admission were collected.Multiple differences in patient and hospital factors were found between patients receiving a new, early DNR order and those who did not receive a DNR order after ICH. In regression modeling, Caucasian race, direct admission, and higher ICH score were associated with placement of a new DNR order early in the course of injury.Race, transfer procedures, and injury severity may be important factors associated with placement of new, early DNR orders in patients after ICH.

Objective To discuss common myths and misperceptions about spontaneous intracranial hypotension (SIH), focusing on common issues related to diagnosis and treatment, and to review the evidence that contradicts and clarifies these myths. Background Recognition of SIH has increased in recent years. With increasing recognition, however, has come an increased demand for management by neurologists and headache specialists, some of whom have little prior experience with the condition. This dearth of practical experience, and lack of awareness of recent investigations into SIH, produces heterogeneity in diagnostic and treatment pathways, driven in part by outdated, confusing, or unsubstantiated conceptions of the condition. We sought to address this heterogeneity by identifying 10 myths and misperceptions that we frequently encounter when receiving referrals for suspected or confirmed SIH, and to review the literature addressing these topics. Methods Ten topics relevant to diagnosis and treatment SIH were generated by the authors. A search for studies addressing SIH was conducted using PubMed and EMBASE, limited to English language only, peer reviewed publications from inception to 2018. Individual case reports were excluded. The resulting studies were reviewed for relevance to the topics in question. Results The search generated 557 studies addressing SIH; 75 case reports were excluded. Fifty-four studies were considered to be of high relevance to the topics addressed, and were included in the data synthesis. The topics are presented in the form of a narrative review. Conclusions The understanding of SIH has evolved over the recent decades, leading to improvements in knowledge about the pathophysiology of the condition, diagnostic strategies, and expanded treatments. Awareness of these changes, and dispelling outdated misconceptions about SIH, is critical to providing appropriate care for patients and guiding future investigations going forward.

CSF-venous fistula is a recently reported cause of spontaneous intracranial hypotension that may occur in the absence of myelographic evidence of CSF leak. Information about this entity is currently very limited, but it is of potential importance given the large percentage of cases of spontaneous intracranial hypotension associated with negative myelography findings. We report 3 additional cases of CSF-venous fistula and describe the “hyperdense paraspinal vein” sign, which may aid in its detection.

The objective of this study is to describe the anatomic and imaging features of CSF venous fistulas, which are a recently reported cause of spontaneous intracranial hypotension (SIH).We retrospectively reviewed the records of patients with SIH caused by CSF venous fistulas who received treatment at our institution. The anatomic details of each fistula were recorded. Attenuation of the veins involved by the fistula was compared with that of adjacent control veins on CT myelography (CTM). Visibility of the CSF venous fistula on CTM and a modified conventional myelography technique we refer to as dynamic myelography was also compared.Twenty-two cases of CSF venous fistula were identified. The fistulas were located between T4 and L1. Ninety percent occurred without a concurrent epidural CSF leak. In most cases (82%), the CSF venous fistula originated from a nerve root sleeve diverticulum. On CTM, the abnormal veins associated with the CSF venous fistula were seen in a paravertebral location in 45% of cases, centrally within the epidural venous plexus in 32%, and lateral to the spine in 23%. Differences in attenuation between the fistula veins and the control veins was highly statistically significant (p0.0001), with a threshold of 70 HU perfectly discriminating fistulas from normal veins in our series. When both CTM and dynamic myelography were performed, the fistula was identified on both modalities in 88% of cases.CSF venous fistulas are an important cause of SIH that can be detected on both CTM and dynamic myelograph y and may occur without an epidural CSF leak. Familiarity with the imaging characteristics of these lesions is critical to providing appropriate treatment to patients with SIH.

The purpose of this study is to provide an update on recent developments in the understanding, diagnosis, and treatment of spontaneous intracranial hypotension (SIH). SIH is an important cause of headaches caused by spinal cerebrospinal fluid (CSF) leaks, with an increasingly broad spectrum of clinical presentations and diagnostic findings. A simple conception of the condition as being defined by the presence of low CSF pressure is no longer sufficient or accurate. A number of etiologies for spinal CSF leaks have been identified, including the recent discovery of CSF-venous fistulas, and these various etiologies may require different diagnostic and therapeutic pathways in order to affect a cure. Familiarity with the spectrum of presentations and causes of SIH is critical to accurate and timely diagnosis and management. Challenges exist in both diagnosis and treatment, and require understanding of the underlying pathogenesis of the condition in order to appropriately select testing and treatment. Prospective studies are needed going forward in order to inform workup and guide treatment decisions.

Object Cerebrospinal fluid leaks due to unrecognized durotomy during spinal surgery are often managed with a second surgery for dural closure. CT-guided percutaneous patching targeted to the dural defect offers an alternative to surgery since it can be performed in a minimally invasive fashion without the need for general anesthesia. This case series describes the authors' experience using targeted CT-guided percutaneous patching to repair incidental durotomies incurred during spinal surgery. Methods This investigation is a retrospective case series involving patients who underwent CT-guided percutaneous patching of surgical incidental durotomies and were referred between January 2007 and June 2013. Their presenting clinical history, myelographic findings, and clinical outcomes, including the need for eventual surgical duraplasty, were reviewed. Results Nine cases were identified, including 7 durotomies incurred during lumbar discectomy, one due to a medial transpedicular screw breach, and one incurred during vertebrectomy for spinal osteosarcoma. All patients who had favorable outcomes with percutaneous intervention alone had 2 common features: dural defect of 4 mm or smaller and absence of a pseudomeningocele. Patients with CSF leaks complicated by pseudomeningocele and those with a dural defect of 6 mm or more all required eventual surgical management. Conclusions The authors' results suggest that findings on CT myelography may help predict which patients with postsurgical durotomy can be treated with percutaneous intervention. In particular, CT-guided patching may be more likely to be successful in those patients with dural defects of less than 5 mm and without pseudomeningocele. In patients with larger dural defects or pseudomeningoceles, percutaneous blood patching alone is unlikely to be successful.

Spontaneous intracranial hemorrhage is a neurological emergency commonly encountered by the emergency radiologist. This article reviews the approach to spontaneous brain parenchymal hemorrhage, including common causes and the role of various neuroimaging modalities in the diagnostic workup. We emphasize the need for a primary survey directed at conveying information needed for emergent clinical management of the patient and a secondary survey directed at identifying the etiology of the hemorrhage.

Adult malignant brainstem gliomas (BSGs) are poorly characterized due to their relative rarity. We have examined histopathologically confirmed cases of adult malignant BSGs to better characterize the patient and tumor features and outcomes, including the natural history, presentation, imaging, molecular characteristics, prognostic factors, and appropriate treatments. A total of 34 patients were identified, consisting of 22 anaplastic astrocytomas (AAs) and 12 glioblastomas (GBMs). The overall median survival for all patients was 25.8 months, with patients having GBMs experiencing significantly worse survival (12.1 vs. 77.0 months, p = 0.0011). The majority of tumors revealed immunoreactivity for EGFR (93.3 %) and MGMT (64.7 %). Most tumors also exhibited chromosomal abnormalities affecting the loci of epidermal growth factor receptor (92.9 %), MET (100 %), PTEN (61.5 %), and 9p21 (80 %). AAs more commonly appeared diffusely enhancing (50.0 vs. 27.3 %) or diffusely nonenhancing (25.0 vs. 0.0 %), while GBMs were more likely to exhibit focal enhancement (54.6 vs. 10.0 %). Multivariate analysis revealed confirmed histopathology for GBM to significantly affect survival (HR 4.80; 95 % CI 1.86–12.4; p = 0.0012). In conclusion, adult malignant BSGs have an overall poor prognosis, with GBM tumors faring significantly worse than AAs. As AAs and GBMs have differing imaging characteristics, tissue diagnosis may be necessary to accurately determine patient prognosis and identify molecular characteristics which may aid in the treatment of these aggressive tumors.

We prospectively compared the ability of neuroradiologists to diagnose medulloblastoma with novice raters using only apparent diffusion coefficient (ADC) values measured on ADC maps. One hundred and three pediatric patients with pre-operative magnetic resonance imaging scans showing a posterior fossa tumor with histological verification were retrospectively identified from a ten-year period at a tertiary care medical center. A single observer measured the lowest ADC values in all tumors to determine the mean minimum ADC (ADCmin) value that provided greatest accuracy in distinguishing medulloblastomas from other tumors, which was determined to be 0.66×10−3 mm2/s. Imaging studies, including ADC maps, from 90 patients were provided to two neuroradiologists, who provided a diagnosis, which was later dichotomized as medulloblastoma or other. Two medical students measured ADCmin within tumors and those with ADCmin < 0.66×10−3 mm2/s were recorded as medulloblastoma; any other value was recorded as other. Diagnostic accuracy was measured. ADCmin values allowed a correct identification of lesions as either medulloblastoma or other in 91% of cases. After diagnoses by the two neuroradiologists were categorized as either medulloblastoma or other, their diagnoses were correct in 90% and 84% of cases, respectively. In 19 cases, at least one neuroradiologist was incorrect; the addition of ADC values to clinical interpretation would have allowed a correct diagnosis in 63% of such cases. Diagnostic accuracy based on ADC values by medical students was comparable to that of sub specialty-trained neuroradiologists. Our findings suggest that the addition of ADC values to standard film interpretation may improve the diagnostic rate for these tumors.

OBJECTIVE. The purpose of this study was to determine the number of thyroid nodule workups that could be eliminated and the number of malignant tumors that would be missed if the Society of Radiologists in Ultrasound (SRU) recommendations and the three-tiered system were applied to incidental thyroid nodules (ITN) detected at imaging. MATERIALS AND METHODS. This retrospective study included ITN in 390 consecutively registered patients who underwent ultrasound-guided fine-needle aspiration of one or more thyroid nodules from July 2010 to June 2011. Images were reviewed, and nodules were categorized according to two workup criteria: ITN seen on ultrasound images were categorized according to SRU recommendations, and those seen on CT, MR, or PET/CT images were classified according to the three-tiered risk-categorization system. RESULTS. In this study 114 of 390 (29%) patients had nodules first detected incidentally during imaging studies, and 107 patients met the inclusion criteria. These patients had 47 ITN...

This study investigated the degree to which body habitus influences radiation dose during CT fluoroscopy (CTF)-guided lumbar epidural steroid injections (ESI). An anthropomorphic phantom containing metal oxide semiconductor field effect transistor (MOSFET) detectors was scanned at two transverse levels to simulate upper and lower lumbar CTF-guided ESI. Circumferential layers of adipose-equivalent material were sequentially added to model patients of three sizes: small (cross-sectional dimensions 25×30 cm), average (34×39 cm), and oversize (43×48 cm). Point dose rates to skin and internal organs within the CTF beam were measured. Scattered point dose rates 5 cm from the radiation beam were also measured. Direct point dose rates to the internal organs ranged from 0.05–0.11 mGy/10mAs in the oversized phantom, and from 0.18–0.43 mGy/10mAs in the small phantom. Skin direct point dose rates ranged from 0.69–0.71 mGy/10mAs in the oversized phantom and 0.88–0.94 mGy/10mAs in the small phantom. This represents a 180–310% increase in organ point dose rates and 24–36% increase in skin point dose rates in the small habitus compared with the oversize habitus. Scatter point dose rates increased by 83–117% for the small compared to the oversize phantom. Decreasing body habitus results in substantial increases in direct organ and skin point doses as well as scattered dose during simulated CTF-guided procedures. Failure to account for individual variations in body habitus will result in inaccurate dose estimation and inappropriate choice of tube current in CTF-guided procedures.

The cerebral organization of language in epilepsy patients has been studied with invasive procedures such as Wada testing and electrical cortical stimulation mapping and more recently with noninvasive neuroimaging techniques, such as functional MRI. In the setting of a chronic seizure disorder, clinical variables have been shown to contribute to cerebral language reorganization underscoring the need for language lateralization and localization procedures. We present a 14-year-old pediatric patient with a refractory epilepsy disorder who underwent two neurosurgical resections of a left frontal epileptic focus separated by a year. He was mapped extraoperatively through a subdural grid using cortical stimulation to preserve motor and language functions. The clinical history and extensive workup prior to surgery is discussed as well as the opportunity to compare the cortical maps for language, motor, and sensory function before each resection. Reorganization in cortical tongue sensory areas was seen concomitant with a new zone of ictal and interictal activity in the previous tongue sensory area. Detailed neuropsychological data is presented before and after any surgical intervention to hypothesize about the extent of reorganization between epochs. We conclude that intrahemispheric cortical plasticity does occur following frontal lobe resective surgery in a teenager with medically refractory seizures.

Intracranial dermoid cysts are rare congenital lesions that typically occur in the cisternal spaces. However, exceptionally rare cases of intraaxial involvement have been reported, with only 8 cases having been described in the literature. The authors report the first case of an intraaxial dermoid cyst located in the medulla and the first occurrence in an elderly patient. They also review the literature of the existing intraparenchymal cases and provide treatment guidelines. A 66-year-old man presented with slowly progressive dysphagia, left lower-extremity numbness, nausea, and hyperhidrosis. Neurological examination revealed decreased pinprick sensation of the left side of his face and body, and decreased vibratory sensation in his left lower extremity. Additionally, he had an unusual extraocular movement in which abduction of the eye resulted in closure of the contralateral eye. Magnetic resonance imaging revealed a nonenhancing cystic lesion centered in the medulla. The patient underwent a suboccipital craniotomy with laminectomy of C1–2 for excision of the cyst, with subtotal resection due to adherence of the cyst wall to the brainstem. At follow-up 7.5 years after surgery, the patient's neurological examination was stable. Magnetic resonance imaging did not reveal any progression or recurrence of the cyst. As the cyst wall is typically adherent to surrounding structures, resection is usually subtotal due to the risk of neurological deficits. As there have been no cases of progression after subtotal resection, gross-total resection is not warranted for the treatment of these lesions.

BACKGROUND AND PURPOSE: Contrast is used in CT-guided epidural steroid injections to ensure proper needle placement. Once injected, undiluted contrast often obscures the needle, hindering subsequent repositioning. The purpose of this investigation was to establish the optimal contrast dilution for CT-guided epidural steroid injections. MATERIALS AND METHODS: This investigation consisted of an initial phantom study, followed by a prospective, randomized, single-center trial assessing a range of contrast dilutions. In the phantom study, a phantom housing a chamber containing a 22-gauge needle and various dilutions of contrast was scanned, and images were evaluated for needle visibility. On the basis of these results, concentrations of 66, 100, 133, and 150 mg/mL iodine were selected for evaluation in a clinical study. Patients presenting for CT-guided epidural steroid injections were randomly assigned to a contrast dilution, and images from the procedure were evaluated by 2 readers blinded to the contrast assignment. Needle visibility was scored by use of a 5-point scale. RESULTS: In the phantom study, the needle was not visible at contrast concentrations of ≥133 mg/mL. In the clinical study, needle visibility was strongly associated with contrast concentration (P < .0001). Significant improvements in visibility were found in 66 mg/mL and 100 mg/mL compared with higher iodine concentrations; no difference was found comparing 66 mg/mL with 100 mg/mL iodine. Neither injection location (cervical versus lumbar) nor technique (interlaminar versus transforaminal) influenced visibility scores. CONCLUSIONS: For CT-guided epidural steroid injections, the optimal contrast concentration is 66–100 mg/mL iodine. Because these concentrations are not commercially available, proceduralists must dilute their contrast for such procedures.

Subdural hematomas (SDHs) comprise a significant percentage of missed intracranial hemorrhage on axial brain CT. SDH detection rates could be improved with the addition of reformatted images. Though performed at some centers, the potential additional diagnostic sensitivity of reformatted images has not yet been investigated. The purpose of our study is to determine if the addition of coronal and sagittal reformatted images to an axial brain CT increases the sensitivity and specificity for detection of acute traumatic SDH. We retrospectively reviewed consecutive brain CTs acquired for acute trauma that contained new SDHs. An equivalent number of normal brain CTs served as control. Paired sets of images were created for each case: (1) axial images only ("axial only") and (2) axial, coronal, sagittal images ("reformat added"). Three readers interpreted both the axial only and companion reformat added for each case, separated by 1 month. Reading times and SDH detection rates were compared. One hundred SDH and 100 negative examinations were collected. Sensitivity and specificity for the axial-only scans were 75.7 and 94.3 %, respectively, compared with 88.3 and 98.3 % for reformat added. There was a 24.3 % false negative (missed SDH) rate with axial-only scans versus 11.7 % with reformat added (p =

BACKGROUND AND PURPOSE: Patients with spontaneous intracranial hypotension often exhibit low CSF pressure and changes on brain MR imaging and/or evidence of CSF leak on myelography. We investigated whether individual imaging signs of spontaneous intracranial hypotension correlate with measured CSF pressure and how frequently these 2 markers of spontaneous intracranial hypotension were concordant. MATERIALS AND METHODS: We performed a retrospective, cross-sectional study of 99 subjects with spontaneous intracranial hypotension. Prevalence of brain and myelographic imaging signs of spontaneous intracranial hypotension was recorded. CSF pressure among subjects with or without individual imaging signs was compared by using a 2-tailed t test and ANOVA. Concordance between low CSF pressure (≤6 cm H 2 O) and imaging was defined as the presence of the sign in a subject with low CSF pressure or absence of the sign when pressure was not low. RESULTS: Dural enhancement, brain sagging, and venous distension sign were present in 83%, 61%, and 75% of subjects, respectively, and myelographic evidence of CSF leak was seen in 55%. Marginal correlations between CSF pressure and brain sagging ( P = .046) and the venous distension sign ( P = .047) were found. Dural enhancement and myelographic evidence of leak were not significantly correlated with CSF pressure. Rates of concordance between imaging signs and low CSF pressure were generally low, ranging from 39% to 55%. CONCLUSIONS: Brain and myelographic signs of spontaneous intracranial hypotension correlate poorly with CSF pressure. These findings reinforce the need to base the diagnosis of spontaneous intracranial hypotension on multiple diagnostic criteria and suggest the presence of patient-specific variables that influence CSF pressure in these individuals.

BACKGROUND AND PURPOSE: The aim of CT-guided CTSI is to inject medication into the foraminal region where the nerve root is inflamed. The optimal location for needle placement and therapeutic delivery, however, remain uncertain. The purpose of this study was to investigate how needle positioning and angle of approach impact the transforaminal distribution of injectate. MATERIALS AND METHODS: We retrospectively reviewed fluoroscopic images from 90 CT-guided CTSI procedures for needle-tip location, needle angle, and contrast distribution. Needle-tip position was categorized as either foraminal zone, junctional, or extraforaminal. Distribution of contrast injected immediately before steroid administration was categorized as central epidural, intraforaminal, or extraforaminal in location. Needle-tip location and angle were correlated with contrast distribution. RESULTS: The needle tip was most commonly placed in the junctional position (36 cases, 40%), followed by foraminal (30 cases, 33%) and extraforaminal (24 cases, 27%) locations. Intraforaminal contrast distribution was highest when the needle location was foraminal (30/30, 100%) or junctional (35/36, 97%), compared with extraforaminal (7/24, 29%) (P value .0001). There was no relationship between needle angle and contrast distribution. CONCLUSIONS: Needle-tip location at the outer edge of the neural foramen (junctional location) correlated well with intraforaminal distribution of contrast for CT-guided CTSI and compared favorably with injectate distribution following foraminal zone needle positioning. Junctional needle positioning may be preferred over the foraminal zone by some proceduralists. Extraforaminal needle positioning resulted in less favorable contrast distribution, which may significantly diminish the therapeutic efficacy of CTSI. ABBREVIATION: CTSI cervical transforaminal steroid injections

Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with neurocognitive impairments. The neural substrates of cognitive impairments in 22q11DS remain poorly understood. Because the corpus callosum (CC) is found to be abnormal in a variety of neurodevelopmental disorders, we obtained volumetric measurements of the CC and its subregions, examined the relationship between these regions and neurocognition and selected genotypes within candidate genes in the 22q11.2 interval in 59 children with 22q11DS and 53 control subjects. The total CC, splenium and genu were significantly larger in children with 22q11DS and the enlargement was associated with better neurocognitive functioning in the 22q11DS group, suggestive of a compensatory increase in the CC volumes. The expected age-related increase in the volume of the CC was not seen in children with 22q11DS, indicative of dysmaturation of the CC in these children. The increased volumes in the genu, splenium and total CC in the 22q11DS group were associated with polymorphisms within the candidate genes: COMT (rs4680), ZDHHC8 (rs175174) and UFD1L (rs5992403). These findings indicate that alterations in the CC volume in children with 22q11DS are associated with cognition and specific genotypes in the 22q11.2 interval.

BACKGROUND AND PURPOSE: Selecting a lower tube current for CT fluoroscopic spine injections is a method of radiation dose reduction. Ideally tube current should be tailored to the patient's body habitus, but a greater influence on tube current may be the proceduralist's personal preference. The purpose of this study was to compare tube current and fluoroscopy time of different proceduralists for lumbar spine CT-guided selective nerve root blocks, and to correlate image quality to patient diameter and tube current. MATERIALS AND METHODS: Eighty CT-guided SNRBs performed by 4 proceduralists were retrospectively reviewed for tube current and fluoroscopy time. Patient body habitus was evaluated by measuring anteroposterior diameters on scout images. Image quality was evaluated objectively and subjectively: noise was measured in the psoas muscle and images were graded on a 3-point scale. RESULTS: The mean tube current was 59 ± 20 mA and mean fluoroscopy time was 10.4 ± 7.5 seconds. The mean tube current between proceduralists differed by almost 2-fold, and there was greater than 2-fold difference in mean fluoroscopy time (P < .0001 and .01, respectively). Mean AP body size was 27 ± 5 cm. When categoric data of tube current and AP diameter were analyzed, only AP diameter was a statistically significant variable influencing image noise (P = .009). Twenty of 23 patients with AP diameter ≤30 cm had adequate to excellent image quality, even with lower tube current of ≤40 mA. CONCLUSIONS: Wide variability in tube current selection between proceduralists calls for a more objective method of selecting tube current to minimize radiation dose. Body size, measured by AP diameter, had the greatest influence on image quality. This could be used to identify patients for lower tube current selection.

OBJECTIVE. Spinal leakage of CSF causes almost all cases of spontaneous intracranial hypotension. Leak detection and localization are important for both diagnosis and treatment. The myelographic appearance of the leaks may vary, however, depending on the cause of the leak, rate of leakage, and imaging modality used. CONCLUSION. The purpose of this article is to review the imaging of spinal CSF leaks and to assist in the selection of appropriate imaging modalities in this condition.

Objectives To determine the proportion of patients with spontaneous intracranial hypotension (SIH) who had a cerebrospinal fluid (CSF) pressure >6 cm H2O and to investigate the clinical and imaging variables associated with CSF pressure ( PCSF) in this condition. Methods We retrospectively reviewed 106 patients with SIH. PCSF was measured by lumbar puncture prior to treatment. Clinical and imaging variables – including demographic data, brain imaging results, symptom duration, and abdominal circumference – were collected. Univariate and multivariate analyses were performed to determine the correlation of these variables with PCSF. Results Sixty-one percent of patients had a PCSF between 6 and 20 cm H2O; only 34% had a PCSF ≤6 cm H2O. The factors associated with increased PCSF included abdominal circumference ( p CSF was observed among all patients, which was not completely accounted for by the variables included in the model. Conclusions Normal CSF pressure is common in patients with SIH; the absence of a low opening pressure should not exclude this condition. Body habitus, symptom duration, and brain imaging are correlated with PCSF measurements, but these factors alone do not entirely explain the wide variability in observed pressures in this condition and this suggests the influence of other factors.

Objective To investigate the ability to detect the in vivo cochlear changes associated with vasopressin-induced and surgically induced endolymphatic hydrops using MRI at 3 tesla (T). Study Design Prospective, animal model. Setting Animal laboratory. Subjects and Methods In group 1, five guinea pigs underwent post–gadolinium temporal bone MRI before and after seven and 14 days of chronic systemic administration of vasopressin by osmotic pump. In group 2, five guinea pigs underwent temporal bone MRI eight weeks after unilateral surgical ablation of the endolymphatic sac. Three-tesla high-resolution T1-weighted sequences were acquired pre- and postcontrast administration. Region of interest signal intensities of the perilymph and endolymph were analyzed manually. Quantitative evaluation of hydrops was measured histologically. Results Gadolinium preferentially concentrated in the perilymph, allowing for distinction of cochlear compartments on 3.0-T MRI. The T1-weighted contrast MRI of vasopressin-induced hydropic cochlea showed significant increases in signal intensity of the endolymph and perilymph. Surgically induced unilateral hydropic cochlea also showed increased signal intensity, compared with the control cochlea of the same animal, but less of an increase than the vasopressin group. The histological degree of hydrops induced in the vasopressin group was comparable to previous studies. Conclusions In vivo postcontrast MRI of the inner ear demonstrated cochlear changes associated with chronic systemic administration of vasopressin and surgical ablation of the endolymphatic sac. Understanding the MRI appearance of endolymphatic hydrops induced by various methods contributes to the future use of MRI as a possible tool in the diagnosis and treatment of Meniere's disease.

BACKGROUND AND PURPOSE: Inadvertent intravascular injection during epidural steroid injection can result in complications and has been investigated previously with conventional fluoroscopy, but not CT fluoroscopy. The purpose of this study was to determine the incidence of intravascular injections recognized during CT fluoroscopy–guided epidural steroid injection. MATERIALS AND METHODS: We retrospectively reviewed 575 consecutive CT fluoroscopy–guided epidural steroid injections. Procedures were assessed to determine the incidence of intravascular injection. Cases positive for intravascular injection were classified on the basis of anatomic location, distance from the needle tip, washout pattern, and presence of combined epidural and vascular injection. Cases were also graded as either venous or arterial by using a 5-point scale. RESULTS: Intravascular injection was observed in 26% of cervical transforaminal epidural steroid injections (7/27), 9% of cervical interlaminar epidural steroid injections (4/47), 8% of lumbar transforaminal epidural steroid injections (22/275), and 2% of lumbar interlaminar epidural steroid injections (4/222). Vessels were most commonly identified close to the needle, but in 30% of cases, they were visualized in the anterior paraspinal soft tissues remote from the needle. Washout was most commonly delayed (86%), though rapid washout occurred in 14% of cases. Simultaneous epidural and vascular injections occurred in 32% of cases. Most visualized vessels were venous, but 2 cases were classified as probably arterial. CONCLUSIONS: Intravascular injections can be detected with CT fluoroscopy. The incidence in our study was similar to that in previous reports using conventional fluoroscopy. Technical factors such as the “double-tap” on CT fluoroscopy following contrast injection, assessment for discordance between injected and visualized contrast volume, and maintenance of an appropriate FOV facilitate the detection of such events.

OBJECTIVE. We describe the use of CT fluoroscopy as a guidance tool for performing interlaminar epidural steroid injections in the cervical spine. CONCLUSION. CT fluoroscopy is an alternative method to perform cervical interlaminar steroid injections that allows precise needle placement in the epidural space.