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Plexopathy may be caused by diverse pathologies, including trauma, nerve entrapment, neoplasm, inflammation, infection, autoimmune disease, hereditary disease, and idiopathic etiologies. For patients presenting with brachial or lumbosacral plexopathy, dedicated plexus MRI is the most appropriate initial imaging modality for all clinical scenarios and can identify processes both intrinsic and extrinsic to the nerves. Other imaging tests may be appropriate for initial imaging depending on the clinical scenario. This document addresses initial imaging strategies for brachial and lumbosacral plexopathy in the following clinical situations: nontraumatic plexopathy with no known malignancy, traumatic plexopathy (not perinatal), and plexopathy occurring in the context of a known malignancy or posttreatment syndrome. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Spine infection is both a clinical and diagnostic imaging challenge due to its relatively indolent and nonspecific clinical presentation. The diagnosis of spine infection is based upon a combination of clinical suspicion, imaging evaluation and, when possible, microbiologic confirmation performed from blood cultures or image-guided percutaneous or open spine biopsy. With respect to the imaging evaluation of suspected spine infection, MRI without and with contrast of the affected spine segment is the initial diagnostic test of choice. As noncontrast MRI of the spine is often used in the evaluation of back or neck pain not responding to conservative medical management, it may show findings that are suggestive of infection, hence this procedure may also be considered in the evaluation of suspected spine infection. Nuclear medicine studies, including skeletal scintigraphy, gallium scan, and FDG-PET/CT, may be helpful in equivocal or select cases. Similarly, radiography and CT may be appropriate for assessing overall spinal stability, spine alignment, osseous integrity and, when present, the status of spine instrumentation or spine implants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

In the United States, acute low back pain, with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life-years. Uncomplicated acute low back pain and/or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as cauda equina syndrome, malignancy, fracture, or infection. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Coronavirus disease 2019 (COVID-19) myelitis is a rare condition, most commonly presenting with nonenhancing central expansile cord T2 signal changes. A single case report has also described longitudinal involvement of the dorsal columns. We present 5 cases of COVID-19-associated myelitis with tract-specific involvement of the dorsal and lateral columns and discuss potential pathophysiologic pathways for this unique pattern.

Management of patients suffering from low back pain (LBP) is challenging and requires development of diagnostic techniques to identify specific patient subgroups and phenotypes in order to customize treatment and predict clinical outcome. The Back Pain Consortium (BACPAC) Spine Imaging Working Group has developed standard operating procedures (SOPs) for spinal imaging protocols to be used in all BACPAC studies. These SOPs include procedures to conduct spinal imaging assessments with guidelines for standardizing the collection, reading/grading (using structured reporting with semi-quantitative evaluation using ordinal rating scales), and storage of images. This article presents the approach to image acquisition and evaluation recommended by the BACPAC Spine Imaging Working Group. While the approach is specific to BACPAC studies, it is general enough to be applied at other centers performing MRI acquisitions in patients with LBP. The herein presented SOPs are meant to improve understanding of pain mechanisms and facilitate patient phenotyping by codifying MRI-based methods that provide standardized, non-invasive assessments of spinal pathologies. Finally, these recommended procedures may facilitate the integration of better harmonized MRI data of the lumbar spine across studies and sites within and outside of BACPAC studies.

Myelopathy is a clinical diagnosis with localization of the neurological findings to the spinal cord, rather than the brain or the peripheral nervous system, and then to a particular segment of the spinal cord. Myelopathy can be the result of primary intrinsic disorders of the spinal cord or from secondary conditions, which result in extrinsic compression of the spinal cord. While the causes of myelopathy may be multiple, the acuity of presentation and symptom onset frame a practical approach to the differential diagnosis. Imaging plays a crucial role in the evaluation of myelopathy with MRI the preferred modality. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Thoracic outlet syndrome (TOS) is the clinical entity that occurs with compression of the brachial plexus, subclavian artery, and/or subclavian vein at the superior thoracic outlet. Compression of each of these structures results in characteristic symptoms divided into three variants: neurogenic TOS, venous TOS, and arterial TOS, each arising from the specific structure that is compressed. The constellation of symptoms in each patient may vary, and patients may have more than one symptom simultaneously. Understanding the various anatomic spaces, causes of narrowing, and resulting neurovascular changes is important in choosing and interpreting radiological imaging performed to help diagnose TOS and plan for intervention. This publication has separated imaging appropriateness based on neurogenic, venous, or arterial symptoms, acknowledging that some patients may present with combined symptoms that may require more than one study to fully resolve. Additionally, in the postoperative setting, new symptoms may arise altering the need for specific imaging as compared to preoperative evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Introduction Anterior cervical discectomy and fusions (ACDFs) are generally limited to the levels causing neurological symptoms, but whether adjacent asymptomatic levels should be included if they demonstrate severe radiographic degeneration is a matter of controversy. We evaluated whether asymptomatic preoperative magnetic resonance imaging (MRI) abnormalities at adjacent levels were predictive of reoperation for symptomatic adjacent-segment degeneration (ASD) after the initial ACDF. Methods We reviewed patients treated with ACDF in 2000-2010 who had MRIs preoperatively and again ≥3 years after the index surgery to evaluate new neurological symptoms. Patients were stratified by ASD severity score, calculated based on MRI features. The associations between preoperative ASD severity score and reoperation for ASD were evaluated with logistic and Cox regressions after adjusting for covariates. Results Of 1038 patients who underwent ACDF, 96 (9%) had MRI evaluation ≥3 years postoperatively (mean follow-up 78 months). Of the 195 adjacent segments evaluated, 14 (7%) were included in subsequent fusion procedures. The 10-year surgery-free survival estimate was 82.7% (73.4-93.2%). After adjusting for covariates, ASD severity scores were predictive of reoperation only for patients with the highest score (hazard ratio [HR] 4.5 [1.0-19.8]) and those with foraminal stenosis (HR 4.2 [.4-12.7]). However, the prevalence of reoperation for ASD in these groups was only 16% and 15%, respectively. Conclusion The prevalence of reoperation for ASD was low for patients who presented with new symptoms ≥3 years after the index ACDF. Our findings do not support including asymptomatic levels in an anterior fusion construct, even if severe MRI abnormalities are present preoperatively.

Acute changes in mental status represent a broad collection of symptoms used to describe disorders in mentation and level of arousal, including the more narrowly defined diagnoses of delirium and psychosis. A wide range of precipitating factors may be responsible for symptom onset including infection, intoxication, and metabolic disorders. Neurologic causes that may be detected on neuroimaging include stroke, traumatic brain injury, nonconvulsive seizure, central nervous system infection, tumors, hydrocephalus, and inflammatory disorders. Not infrequently, two or more precipitating factors may be found. Neuroimaging with CT or MRI is usually appropriate if the clinical suspicion for an acute neurological cause is high, where the cause of symptoms is not found on initial assessment, and for patients whose symptoms do not respond appropriately to management. There was disagreement regarding the appropriateness of neuroimaging in cases where a suspected, nonneurologic cause is found on initial assessment. Neuroimaging with CT is usually appropriate for patients presenting with delirium, although the yield may be low in the absence of trauma or a focal neurological deficit. Neuroimaging with CT or MRI may be appropriate in the evaluation of new onset psychosis, although the yield may be low in the absence of a neurologic deficit. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

A palpable neck mass may be the result of neoplastic, congenital, or inflammatory disease. Older age suggests neoplasia, and a congenital etiology is more prevalent in the pediatric population. The imaging approach is based on the patient age, mass location, and clinical pulsatility. Underlying human papillomavirus-related malignancy should be considered in all age groups. Although the imaging appearance of some processes in the head and neck overlap, choosing the appropriate imaging examination may allow a specific diagnosis, or a limited differential diagnosis. Tissue sampling is indicated to confirm suspected malignancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Injuries to the cervical and thoracolumbar spine are commonly encountered in trauma patients presenting for treatment. Cervical spine injuries occur in 3% to 4% and thoracolumbar fractures in 4% to 7% of blunt trauma patients presenting to the emergency department. Clear, validated criteria exist for screening the cervical spine in blunt trauma. Screening criteria for cervical vascular injury and thoracolumbar spine injury have less validation and widespread acceptance compared with cervical spine screening. No validated criteria exist for screening of neurologic injuries in the setting of spine trauma. CT is preferred to radiographs for initial assessment of spine trauma. CT angiography and MR angiography are both acceptable in assessment for cervical vascular injury. MRI is preferred to CT myelography for assessing neurologic injury in the setting of spine trauma. MRI is usually appropriate when there is concern for ligament injury or in screening obtunded patients for cervical spine instability. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Nontraumatic neck pain is a leading cause of disability, with nearly 50% of individuals experiencing ongoing or recurrent symptoms. Radiographs are appropriate as initial imaging for cervical or neck pain in the absence of "red flag" symptoms or if there are unchanging chronic symptoms; however, spondylotic changes are commonly identified and may result in both false-positive and false-negative findings. Noncontrast CT can be complementary to radiographs for evaluation of new or changing symptoms in the setting of prior cervical spine surgery or in the assessment of extent of ossification in the posterior longitudinal ligament. Noncontrast MRI is usually appropriate for assessment of new or increasing radiculopathy due to improved nerve root definition. MRI without and with contrast is usually appropriate in patients with new or increasing cervical or neck pain or radiculopathy in the setting of suspected infection or known malignancy. Imaging may be appropriate; however, it is not always indicated for evaluation of cervicogenic headache without neurologic deficit. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

PURPOSE To perform a quantitative evaluation of myelination on WT and myelin-deficient (shiverer) mouse spinal cords using ultrahigh-b diffusion-weighted imaging (UHb-DWI). METHODS UHb-DWI of ex vivo on spinal cord specimens of two shiverer (C3HeB/FeJ-shiverer, homozygous genotype for MbPshi ) and six WT (Black Six, C3HeB/FeJ) mice were acquired using 3D multishot diffusion-weighted stimulated-echo EPI, a homemade RF coil, and a small-bore 7T MRI system. Imaging was performed in transaxial plane with 75 × 75 μm2 in-plane resolution, 1-mm-slice thickness, and radial DWI using bmax = 42,890 s/mm2 . Histological evaluation was performed on upper thoracic sections using optical and transmission electron microscopy. Numerical Monte Carlo simulations (MCSs) of water diffusion were performed to facilitate interpretation of UHb-DWI signal-b curves. RESULTS The white matter ultrahigh-b radial DWI (UHb-rDWI) signal-b curves of WT mouse cords behaved biexponentially with high-b diffusion coefficient DH < 0.020 × 10-3 mm2 /s. However, as expected with less myelination, the signal-b of shiverer mouse cords behaved monoexponentially with significantly greater DH = 0.162 × 10-3 , 0.142 × 10-3 , and 0.164 × 10-3 mm2 /s at anterodorsal, posterodorsal, and lateral columns, respectively. The axial DWI signals of all mouse cords behaved monoexponentially with D = (0.718-1.124) × 10-3 mm2 /s. MCS suggests that these elevated DH are mainly induced by increased water exchange at the myelin sheath. Microscopic results were consistent with the UHb-rDWI findings. CONCLUSION UHb-DWI provides quantitative differences in myelination of spinal cords from myelin-deficit shiverer and WT mice. UHb-DWI may become a powerful tool to evaluate myelination in demyelinating disease models that may translate to human diseases, including multiple sclerosis.

BACKGROUND AND PURPOSE: The National Institute of Neurological Disorders and Stroke common data elements initiative was created to provide a consistent method for recording and reporting observations related to neurologic diseases in clinical trials. The purpose of this study is to validate the subset of common data elements related to MR imaging evaluation of acute spinal cord injury. MATERIALS AND METHODS: Thirty-five cervical and thoracic MR imaging studies of patients with acute spinal cord injury were evaluated independently in 2 rounds by 5 expert reviewers. Intra- and interrater agreement were calculated for 17 distinct MR imaging observations related to spinal cord injury. These included ordinal, categoric, and continuous measures related to the length and location of spinal cord hemorrhage and edema as well as spinal canal and cord measurements. Level of agreement was calculated using the interclass correlation coefficient and kappa. RESULTS: The ordinal common data elements spinal cord injury elements for lesion center and rostral or caudal extent of edema or hemorrhage demonstrated agreement ranging from interclass correlation coefficient 0.68 to 0.99. Reproducibility ranged from 0.95 to 1.00. Moderate agreement was observed for absolute length of hemorrhage and edema (0.54 to 0.60) with good reproducibility (0.78 to 0.83). Agreement for the Brain and Spinal Injury Center score showed the lowest interrater agreement with an overall kappa of 0.27 (0.20, 0.34). For 7 of the 8 variables related to spinal cord injury, agreement improved between the first and second evaluation. Continuous diameter measures of the spinal cord and spinal canal using interclass correlation coefficient varied substantially (0.23 to 0.83). CONCLUSIONS: Agreement was more consistent for the ordinal measures of spinal cord injury than continuous measures. Good to excellent agreement on length and location of spinal cord hemorrhage and edema can be achieved with ordinal measures alone.

Purpose To determine optimal timing of biopsy for suspected discitis-osteomyelitis (DOM) with respect to preliminary blood culture results and the effect of biopsy timing on hospital length of stay (LOS). Materials and Methods This retrospective study reviewed disc/vertebral biopsies for suspected DOM performed between 2010 and 2018. A total of 107 disc/vertebral biopsies were performed on 96 inpatients (mean ± SD age 57.9 ± 14.5 years, 68 men/28 women) for suspected DOM, and 100 cases of DOM were clinically confirmed and treated. Descriptive and regression statistics were performed with LOS as the primary outcome. Results Of disc biopsies in clinically confirmed cases, 68% were positive; 20% of all biopsies had preliminary positive blood cultures after 2 hospital days. There was no difference in LOS between cases with biopsy performed ≤ 2 days after blood culture and cases with biopsy performed > 2 days after blood culture (P = .40). Regression analysis showed no association between positive biopsy results and sepsis, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP). Biopsy yield was not significantly decreased in patients previously taking antibiotics (P = .09). Conclusions Waiting 2 days for preliminary blood culture results could avoid disc/vertebral biopsy in 20% of patients and does not significantly impact hospital LOS. Additionally, clinical factors (sepsis, WBC count, CRP, and ESR) do not have predictive value for positive disc biopsy results.

BACKGROUND AND PURPOSE: Patient preparation for myelography and postprocedural monitoring varies widely between practices, despite published guidelines. Our aim was to examine the current practice variations in discontinuing reportedly seizure threshold–lowering medications before myelography and to assess the reported incidence of postmyelographic seizures. MATERIALS AND METHODS: An e-mail survey was sent to American Society of Neuroradiology members concerning the number of postmyelographic seizures experienced in the past 5 years, the presence of an institutional policy for discontinuing seizure threshold–lowering medications, and the type of myelographic contrast used. We compared the postmyelographic seizure frequency in the responses. RESULTS: Of 700 survey responses, 57% reported that they do not discontinue seizure threshold–lowering medications before myelography. Most (97%) indicated never having a patient experience a seizure following myelography. The number of postmyelographic seizures between those who discontinue seizure threshold–lowering medications and those who do not was not statistically significant (OR = 2.13; 95% CI, 0.91–4.98; P = .08). Most (95%) reported using nonionic hypo-osmolar agents. CONCLUSIONS: Survey results revealed widely variable practices for patient myelography preparation and postprocedural monitoring. We found no difference in reported seizures between those who discontinued seizure threshold–lowering medications and those who did not. In light of our findings, we propose that discontinuing reportedly seizure threshold–lowering medications is not warranted with the current nonionic water-soluble contrast agents and may be potentially harmful in some instances. This work supports revision of existing recommendations to withhold such medications before myelography.

This article presents guidelines for imaging utilization in patients presenting with hearing loss or vertigo, symptoms that sometimes occur concurrently due to proximity of receptors and neural pathways responsible for hearing and balance. These guidelines take into account the superiority of CT in providing bony details and better soft-tissue resolution offered by MRI. It should be noted that a dedicated temporal bone CT rather than a head CT best achieves delineation of disease in many of these patients. Similarly, optimal assessment often requires a dedicated high-resolution protocol designed to assess temporal bone and internal auditory canals even though such a study will be requested and billed as a brain MRI. Angiographic techniques are helpful in some patients, especially in the setting of vertigo. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Background Injury in the cervical spinal cord (CSC) can lead to varying degrees of neurologic deficit and persistent disability. Diffusion tensor imaging (DTI) is a promising method to evaluate white matter integrity and pathology. However, the conventional DTI results are limited with respect to the specific details of neuropathology and microstructural architecture. In this study we used ultrahigh-b radial-DWI (UHb-rDWI) with b-values ranging from 0 to ∼7500 s/mm2 and calculated decay constant (DH ) at the high b-values, which gives much deeper insight about the microscopic environment of CSC white matter. Purpose To evaluate a novel diffusion MRI, UHb-rDWI technique for imaging of the CSC. Study type Longitudinal. Subjects Four healthy controls, each scanned twice. Field strength/sequence 3T/2D single shot diffusion-weighted stimulated echo planar imaging with reduced field of view. Assessment The signal from each pixel of b0 (b = 0) and b-value (b ≠ 0) images were fitted to a biexponential function and normalized. The signal-b curve is obtained by dividing the latter curve by the former. DH was obtained from the curve at b >4000 s/mm2 . A Monte-Carlo Simulation (MCS) was performed to investigate how DH changes upon the increased water-exchange at the CSC. Results The signal-b curves plotted at multiple levels of healthy CSC are almost identical on two successive scans and show a biexponential decay behavior: fast exponential decay at lower b-values and much slower decay at UHb-values. The mean values of DH were measured as (0.0607 ± 0.02531) ×10-3 and (0.0357 ± 0.02072) ×10-3 s/mm2 at the lateral funiculus and posterior column, respectively. MCS of diffusion MRI shows that the DH is elevated by increased water exchange between the intra- and extraaxonal spaces. Data conclusion UHb-rDWI signal-b plots of the normal CSC were highly reproducible on successive scans and their biexponential decay behavior can be used to characterize normal spinal white matter. Level of evidence 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:204-211.

Sinonasal imaging is performed in 2 major clinical scenarios: inflammatory rhinosinusitis or suspected mass lesion. Rhinosinusitis affects more than 16% of the US population annually. It poses an immense economic burden, accounting for more than 26 million outpatient visits annually and costing more than $4.3 billion annually in direct medical expenses. Most cases of uncomplicated acute and subacute rhinosinusitis are diagnosed clinically and should not require any imaging procedure. CT of the sinuses without contrast is the imaging method of choice in patients with recurrent acute sinusitis or chronic sinusitis. Sinusitis cannot be diagnosed on the basis of imaging findings alone. CT scan findings should be interpreted in conjunction with clinical and endoscopic findings. MRI is currently used for evaluation of sinus disease as a complementary study in cases of aggressive sinus infection with ocular/intracranial complications, potential invasive fungal sinusitis in immunocompromised patients or in the evaluation of a sinonasal mass. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Tinnitus is the perception of sound in the absence of an external source. It is a common symptom that can be related to hearing loss and other benign causes. However, tinnitus may be disabling and can be the only symptom in a patient with a central nervous system process disorder. History and physical examination are crucial first steps to determine the need for imaging. CT and MRI are useful in the setting of pulsatile tinnitus to evaluate for an underlying vascular anomaly or abnormality. If there is concomitant asymmetric hearing loss, neurologic deficit, or head trauma, imaging should be guided by those respective ACR Appropriateness Criteria® documents, rather than the presence of tinnitus. Imaging is not usually appropriate in the evaluation of subjective, nonpulsatile tinnitus that does not localize to one ear. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

There is a paucity of evidence-based literature regarding the advantages and disadvantages of the interlaminar approach and needle bevel orientation for performing a lumbar interlaminar epidural steroid injection (ESI). The purpose of this study was to determine if superior versus inferior lamina approach, needle bevel tip orientation, or both may predispose to inadvertent nonepidural penetration during lumbar interlaminar ESI.A prospective study was performed of patients with low back pain with or without radicular pain or neurogenic claudication referred for lumbar interlaminar ESI. Two hundred eleven patients were randomized by interlaminar approach (superior vs inferior) and bevel tip orientation (cranial vs caudal). Lumbar interlaminar ESI was performed by six interventionalists of varying levels of experience using fluoroscopic guidance with curved tip epidural needles, using loss-of-resistance technique and confirmation with contrast opacification. Exact Poisson regression was used to model the study outcome.Two hundred twenty-one lumbar interlaminar ESIs were performed on 211 patients, randomized to a superior (n = 121) or inferior lamina approach (n = 100) and to a cranial (n = 103) or caudal (n = 118) orientation of the bevel tip. Epidural needle placement was confirmed in 96.4% (n = 213) of cases. Nonepidural needle placement was most commonly associated with superior lamina approach and caudal bevel tip orientation, which was marginally significant (adjusted risk ratio, 6.88; 95% CI, 0.93-∞; p = 0.059).Inadvertent nonepidural needle penetration during fluoroscopically guided lumbar interlaminar ESI appears to be affected by approach, with superior lamina approach and caudal bevel tip orientation being the least favorable technique.

High-resolution vessel wall MRI (vwMRI) of the intracranial arteries is an emerging diagnostic imaging technique with the goal of evaluating vascular pathology. vwMRI sequences have high spatial resolution and directly image the vessel wall by suppressing blood signal. With vwMRI, it is possible to identify distinct morphologic and enhancement patterns of atherosclerosis that can provide important information about stroke etiology and recurrence risk. We present a review of vwMRI research in relation to intracranial atherosclerosis, with a focus on the relationship between ischemic stroke and atherosclerotic plaque T1 post-contrast enhancement or plaque/vessel wall morphology. The goal of this review is to provide readers with the most current understanding of the reliability, incidence, and importance of specific vwMRI findings in intracranial atherosclerosis, to guide their interpretation of vwMRI research, and help inform clinical interpretation of vwMRI. We will also provide a translational perspective on the existing vwMRI literature and insight into future vwMRI research questions and objectives. With increased use of high field strength MRI, powerful gradients, and improved pulse sequences, vwMRI will become standard-of-care in the diagnosis and prognosis of patients with cerebrovascular disease, making a firm grasp of its strengths and weakness important for neuroimagers.

We present 5 cases of demyelination in patients diagnosed with multiple sclerosis that are closely associated with a developmental venous anomaly. Although the presence of a central vein is a known phenomenon with multiple sclerosis plaques, demyelination occurring around developmental venous anomalies is an underreported phenomenon. Tumefactive demyelination can cause a diagnostic dilemma because of its overlapping imaging findings with central nervous system neoplasm. The relationship of a tumefactive plaque with a central vein can be diagnostically useful, and we suggest that if such a lesion is closely associated with a developmental venous anomaly, an inflammatory or demyelinating etiology should be a leading consideration.

Rationale and Objectives Emergency department (ED) patients with acute low back pain (LBP) may present with ambiguous clinical findings that pose diagnostic challenges to exclude cauda equina syndrome (CES). As a proof of concept, we aimed to determine the efficacy of a rapid lumbar spine (LS) magnetic resonance imaging (MRI) screening protocol consisting of a single 3D-T2 SPACE FS (3D-T2 Sampling Perfection with Application optimized Contrasts using different flip angle Evolution fat saturated) sequence relative to conventional LS MRI to exclude emergently treatable pathologies in this complex patient population. Materials and Methods LS MRI protocol including a sagittal 3D-T2 SPACE FS pulse sequence was added to the routine for ED patients presenting with acute atypical LBP over a 12-month period. Imaging findings were categorically scored on the 3D-T2 SPACE FS sequence and separately on the reference standard conventional LS MRI sequences. Patients' symptoms were obtained from review of the electronic medical record. Descriptive test statistics were performed. Results Of the 206 ED patients who obtained MRI for acute atypical LBP, 118 (43.3 ± 13.5 years of age; 61 female) were included. Specific pathologies detected on reference standard conventional MRI included disc herniation ( n = 30), acute fracture ( n = 3), synovial cyst ( n = 3), epidural hematoma ( n = 2), cerebrospinal fluid leak ( n = 1), and leptomeningeal metastases ( n = 1), and on multiple occasions these pathologies resulted in nerve root impingement ( n = 36), severe spinal canal stenosis ( n = 13), cord/conus compression ( n = 2), and cord signal abnormality ( n = 2). The 3D-T2 SPACE FS sequence was an effective screen for fracture (sensitivity [sens] = 100%, specificity [spec] = 100%), cord signal abnormality (sens = 100%, spec = 99%), and severe spinal canal stenosis (sens = 100%, spec = 96%), and identified cord compression not seen on reference standard. Motion artifact was not seen on the 3D-T2 SPACE FS but noted on 8.5% of conventional LS MRI. Conclusions The 3D-T2 SPACE FS sequence MRI is a rapid, effective screen for emergently actionable pathologies that might be a cause of CES in ED patients presenting with acute atypical LBP. As this abbreviated, highly sensitive sequence requires a fraction of the acquisition time of conventional LS MRI, it has the potential of contributing to increased efficiencies in the radiology department and improved ED throughput.

Interpreting imaging studies of peripheral nerve diseases and especially the brachial plexus (BP) and lumbosacral plexus (LSP) can be challenging. It requires a firm knowledge of the anatomy. It is just as important to be familiar with the end-organ innervations and the surrounding structures, the latter serving as important landmarks.

Unknown spinal lesions are commonly encountered either in the presence of symptoms or incidentally. In addition to tumors, the differential diagnosis should consider nonneoplastic spine tumor mimics, which may be differentiated based on history, physical, and imaging. Treatment strategies diverge considerably from neoplastic counterparts, and care is optimized by considering these entities. General classes include infectious, metabolic, degenerative, inflammatory, hemorrhagic, and other rare entities.

This article reviews image-guided approaches for the treatment of common spine pain generators. The following treatment targets are discussed: epidural space (interlaminar and transforaminal approaches), facet joint, sacroiliac joint, and synovial cysts.

Imaging of neck pain contributes to a significant proportion of health care costs and is expected to increase with current practices that heavily use radiologic studies as a diagnostic tool. Though consensus guidelines are available to assist physicians in selection of appropriate imaging examinations for neck pain, it is unclear if current ordering practices reflect their use and understanding. To investigate this, we analyzed the number and types of imaging examinations performed for neck pain at a university medical center over the past year. Current trends at our institution suggest that clinicians use consensus imaging guidelines, but there is still controversy in the cervical spine for when not to image. To promote appropriate imaging utilization, we developed an algorithm to guide imaging of neck pain, based upon clinical presentation, referral patterns for neck pain, and a review of the literature.

Acute low back pain, defined as less than 6 weeks in duration, does not require imaging in the absence of "red flags" that may indicate a cause, such as fracture, infection, or malignancy. When imaging is indicated, it is important to rule out a host of abnormalities that may be responsible for the pain and any associated symptoms. A common mnemonic VINDICATE can help ensure a thorough consideration of the possible causes.

Purpose: Recent evidence suggests that MRI-detected intraplaque hemorrhage (IPH) improves stroke prediction in all carotid stenosis categories, placing the role of stenosis and impaired perfusion in question. The goal of this study was to determine if carotid stenosis or IPH are associated with baseline perfusion impairment measured by dynamic susceptibility contrast (DSC) and cellular diffusion and perfusion measured by intravoxel incoherent motion (IVIM). Method and Materials: After IRB approval and informed consent, we recruited 25 patients with >=50% stenosis in at least one carotid. Carotid MRI and brain IVIM and DSC were performed at 3T. IVIM was acquired with b-values of 20, 40, 50, 100, 250, 500, and 2000. Post-processing was performed (IVIM with Osirix, and DSC with Olea Sphere). Bilateral regions of interest were drawn in the centrum semiovale with the following measurements obtained for IVIM: percent perfusion fraction (f), tissue diffusion (D), pseudodiffusion (D*) and blood flow related parameter (fD*). DSC parameters included cerebral blood flow (CBF), blood volume (corrected CBV), mean transit time (MTT), and time to peak (TTP). Generalized estimating equations (GEE) and multivariable linear regression was performed accounting for two carotid arteries per patient, to determine the association of each IVIM and DSC perfusion parameter with carotid imaging factors including stenosis, occlusion, near-occlusion, and IPH. Results: Near-occlusion was rare (2/50 carotids) but was the only factor associated with DSC parameters (CBF: coefficient=-9.7, p=0.016, corrected CBV: coefficient=-0.36,p=0.042, MTT: coefficient=1.1,p=0.010, and TTP: coefficient=2.2,p=0.008). Near occlusion was also the only factor associated with the IVIM parameters f (coefficient=1.7, p=0.057) and fD* (coefficient=44, p=0.045). Carotid IPH was the only factor associated with D (coefficient=45, p=0.002). None of the factors were significantly associated with D*. Conclusion: These results suggest that carotid stenosis does not result in decreased baseline cerebral perfusion except in the rare setting of near-occlusion. While these patients may benefit from flow restoration, most patients may primarily benefit from embolic protection.

Spine anatomy can be difficult to master and is essential for performing spine procedures. We sought to utilize the rapidly expanding field of 3D technology to create freely available, interactive educational materials for spine procedures. Our secondary goal was to convey lessons learned about 3D modeling and printing. This project involved two parallel processes: the creation of 3D-printed physical models and interactive digital models. We segmented illustrative CT studies of the lumbar and cervical spine to create 3D models and then printed them using a consumer 3D printer and a professional 3D printing service. We also included downloadable versions of the models in an interactive eBook and platform-independent web viewer. We then provided these educational materials to residents with a pretest and posttest to assess efficacy. The "Spine Procedures in 3D" eBook has been downloaded 71 times as of October 5, 2016. All models used in the book are available for download and printing. Regarding test results, the mean exam score improved from 70 to 86%, with the most dramatic improvement seen in the least experienced trainees. Participants reported increased confidence in performing lumbar punctures after exposure to the material. We demonstrate the value of 3D models, both digital and printed, in learning spine procedures. Moreover, 3D printing and modeling is a rapidly expanding field with a large potential role for radiologists. We have detailed our process for creating and sharing 3D educational materials in the hopes of motivating and enabling similar projects.

Computed tomography (CT) and MRI are complementary imaging modalities for the evaluation of the traumatic spine. Osseous delineation is best assessed with CT, whereas MRI gives superb soft tissue description. Awareness of the strengths and pitfalls of each modality is critical in the accurate interpretation of images. Advances in MR imaging of the spine, particularly of the spinal cord, provide glimpses into to the pathobiological mechanism of spinal cord injury. Innovative techniques relay microstructural information about the integrity of the axons and myelin sheaths. In addition to clinical status, imaging features may be helpful in prognostication and in monitoring therapeutic interventions.