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Objective: Chronic adhesive arachnoiditis (CAA) is rare and has potentially devastating clinical consequences. The objective of this article is to review the clinical features of CAA and describe its appearance on imaging, to increase radiologists' awareness of this challenging diagnosis., Materials and Methods: Twenty-nine cases of advanced CAA seen at our institution over 18 years (1995-2013) were retrospectively reviewed. Chart review was performed, with attention given to data on clinical presentation, suspected cause, and interventions performed. All patients underwent MRI, and seven patients also underwent CT myelography. Clinical and imaging features were evaluated and categorized., Results: The 29 patients ranged in age from 23 to 96 years and included 11 women and 18 men. Suspected underlying causative factors included trauma (n = 10), prior surgery (n = 9), nontraumatic subarachnoid hemorrhage (n = 7), infection (n = 3), myelography with iophendylate used as contrast medium (n = 1), Guillain-Barré syndrome (n = 1), ankylosing spondylitis (n = 1), and unknown causes (n = 1). Imaging characteristics include loculated CSF collections (n = 23), nerve root clumping, enhancement, and displacement (n = 15), cord swelling with increased T2 signal (n = 12), arachnoid septations (n = 11), cord atrophy (n = 6), syrinx (n = 5), and intrathecal calcifications (n = 3). Ten patients underwent surgical procedures, and most had only brief clinical improvement., Conclusion: CAA is a rare cause of devastating neurologic symptoms and chronic pain. The imaging features of CAA range from subtle to severe. Advanced arachnoiditis can present with spinal cord swelling and syrinx formation, which can mimic other disease processes. Inclusion of advanced CAA in the differential diagnosis can prevent unnecessary interventions.

Purpose: We compared signal change on magnetic resonance imaging (MRI) with fat suppression and bone scan activity of lumbar facet joints to determine if these two imaging findings are correlated., Methods: We retrospectively identified all patients who underwent imaging of the lumbar spine for pain evaluation using both technetium-99m methylene disphosphonate single-photon emission computed tomography/computed tomography (99mTc-MDP SPECT/CT) and MRI with at least one fat-suppressed T2- or T1-weighted sequence with gadolinium enhancement within a 180-day interval, at our institution between 1 January 2008 and 19 February 2013. Facet joint activity on 99mTc-MDP SPECT/CT and peri-facet signal change on MRI were rated as normal or increased. Agreement between the two examination types were determined with the κ and prevalence-adjusted bias-adjusted κ (PABAK) statistics., Results: This study included 60 patients (28 male, 47%), with a mean age of 49±19.7 years (range, 12-93 years). The κ value indicated no agreement between 99mTc-MDP SPECT/CT and MRI (κ=-0.026; 95% confidence interval: -0.051, 0.000). The PABAK values were fair to high at each spinal level, which suggests that relatively low disease prevalence lowered the κ values. Together, the κ and PABAK values indicate that there is some degree of intermodality agreement, but that it is not consistent., Conclusion: Overall, facet joint signal change on fat-suppressed MRI did not always correlate with increased 99mTc-MDP SPECT/CT activity. MRI and 99mTc-MDP SPECT/CT for facet joint evaluation should not be considered interchangeable examinations in clinical practice or research.

Objective: The tumefactive variant of cerebral amyloid angiopathy (CAA) is rare. In this article we describe imaging findings associated with this entity and evaluate the role of susceptibility MRI sequences in its diagnosis., Conclusion: Our findings suggest that in elderly patients, susceptibility sequences should be part of prebiopsy MRI for tumefactive lesions. Identification of characteristic diffuse microhemorrhages should prompt inclusion of CAA in the differential diagnosis, targeted biopsy of the cortex and leptomeninges, and pathologic staining for CAA.

This article describes 2 cases of spinal trauma in which diagnostic magnetic resonance imaging (MRI) was correlated with histopathology for diagnosis of a posterior ligamentous complex injury. Spine fractures are common and represent up to 16% of traumatic fractures. Diagnostic imaging currently involves plain films and computerized tomography, but MRI is being used with increasing frequency. The definition of neurologic tissue injury has had substantial documentation in the spinal literature. Clinically, posterior ligamentous complex injury has been associated with facet disruption, gapping of the spinous processes, and significant kyphosis. Assessment of spinal stability in the spine trauma population is based significantly on the assumed disruption or integrity of the posterior ligamentous complex. High signal intensity in the area of the ligamentum flavum and interspinous ligament on fat-saturated T2 MRIs has been associated with the clinical finding of interspinous ligament disruption noted at surgical exploration. Magnetic resonance imaging in spine trauma is widely accepted despite a paucity of data addressing its histopathologic accuracy. To our knowledge, histopathologic correlation of MRI of ligamentous injuries has not been reported., (Copyright 2010, SLACK Incorporated.)

Background and Purpose: Recurrent or residual back pain after vertebroplasty (VP) is common, and many patients with these symptoms are evaluated by MRI. The purpose of this report is to describe post-treatment MRI findings after successful VP., Methods: We identified all patients who underwent VP at our institution and later presented with back pain and had a spine MRI. From these patients, we identified a cohort with uncomplicated procedures, in whom back pain at the site of the VP was not the dominant pain source at follow-up. Using the pre- and postoperative MRIs and the VP conventional radiographs, we assessed such features as interval height loss and changes in marrow edema in treated vertebrae., Results: Thirty patients (51 treated vertebrae) met our clinical criteria for uncomplicated VP. Nine (18%) of 51 vertebrae lost additional height after the procedure. Neither patient demographics nor variables associated with the procedure itself, including volume of cement injected, correlated with additional height loss after VP. Moderate or severe marrow edema was demonstrated in 62% of vertebrae on preoperative MRI and in 33% of vertebrae on follow-up MRI. Twenty-one percent of vertebrae had new areas of marrow edema on follow-up. Twenty-two percent of vertebrae imaged >6 months after VP had moderate or severe edema., Conclusion: Progressive and persistent edema and interval height loss after successful VP are common and should not be interpreted as sufficient evidence of ongoing pathology at the treated vertebral level.

Objectives The S1 dorsal foramen is the route for 30% of lumbar transforaminal epidural injections; it is therefore important to identify structures impeding S1 foraminal access. The study objective was to characterize the imaging findings, prevalence, and anatomic origin of synovial cysts presenting within the S1 neural foramen. Methods A case series (N = 14) established imaging characteristics of S1 synovial cysts. Imaging studies of 400 patients undergoing epidural injections were reviewed for lesions compromising S1 foraminal access. Cadaveric dissections defined the relationship of the inferior recess of the L5-S1 facet to the S1 dorsal foramen. Results Elderly patients (mean age = 76) exhibited S1 synovial cysts. Synovial cysts were typically 1–2 cm in diameter, hyperintense on sagittal T2 weighted magnetic resonance images (MRIs), fluid-density on computed tomography, and dorsal to the S1 spinal nerve. Sixty percent of cysts exhibited complex MRI signal characteristics (thick wall, internal structure). Tarlov cysts, in contrast, were larger, lobular, and exhibited pure fluid intensity. Lesions impeded access to the S1 dorsal foramina in 5% of reviewed imaging studies (16 Tarlov cysts, three synovial cysts, one conjoint S1-S2 nerve root). The multifidus muscle was interposed between the L5-S1 facet inferior recess and the S1 dorsal foramen on dissection specimens; severe atrophy of the ipsilateral multifidus was noted on imaging in 17/18 synovial cysts. Conclusions The S1 neural foramina should be inspected on sagittal MRI, when available, for confounding lesions before performing S1 epidural injections. Tarlov cysts are more common than synovial cysts; the latter are seen in elderly patients with severe multifidus atrophy. [ABSTRACT FROM AUTHOR]

Objective. To examine associations between imaging characteristics of compressive lesions and patient outcomes after lumbar transforaminal epidural steroid injections (TFESIs) stratified by steroid formulation (solution versus suspension). Design/Subjects. Retrospective observational study, academic radiology practice. A 516-patient sample was selected from 2,634 consecutive patients receiving lumbar TFESI for radicular pain. Methods. The advanced imaging study(s) preceding sampled TFESI were reviewed. Compressive lesions were described by a) nature of the lesion [disc herniation, fixed stenosis, synovial cyst, epidural fibrosis, no lesion] b) degree of neural compression [4 part scale], and c) presence of a tandem lesion. Associations between 2-month categorical outcomes (responder rates for pain, functional recovery) and imaging characteristics, stratified by steroid formulation, were examined with chi-squared tests of categorical outcomes and multivariable logistic regression models. Results. Disc herniation patients had more responders for functional recovery than patients with fixed lesions (54% versus 38%, P=0.01). Patients with fixed lesions receiving steroid solution (dexamethasone) had more responders for pain relief, with a similar trend for functional recovery, than patients receiving suspensions (59% versus 40%, P5=0.01). Outcomes for patients with fixed lesions treated with dexamethasone were not statistically different from those for disc herniation patients. Patients with single compressive lesions had more responders than those with tandem lesions (55% versus 41%, P=0.03). Conclusion. In the entire sample, outcomes for disc herniations were more favorable than for fixed lesions. However, fixed lesions treated with dexamethasone had outcomes indistinguishable from disc herniations. Single lesions had better outcomes than tandem lesions. [ABSTRACT FROM AUTHOR]

ABSTRACT Two valuable confirmatory MRI findings of acute spinal cord infarct are highlighted and discussed: concomitant vertebral body infarct and ventral cauda equina nerve root enhancement. [ABSTRACT FROM AUTHOR]