Successful fusion versus pseudarthrosis after spinal instrumentation: a comprehensive imaging review.

PURPOSE: Following spinal instrumentation and fusion, differentiating between successful arthrodesis and pseudoarthrosis on imaging can be challenging. Interpretation of such examinations requires understanding both the expected evolution of postoperative findings and the subtle indicators of pseudoarthrosis across multiple imaging modalities. Due to this level of intricacy, many clinicians lack familiarity with the subject beyond the more rudimentary concepts. METHODS: This review provides an in-depth overview of the imaging of the post-operative spine, with particular emphasis on differentiating between pseudoarthrosis and arthrodesis. RESULTS: A comprehensive overview of imaging of the post-operative spine is given, including the most common imaging modalities utilized, the expected post-operative findings, imaging findings in pseudoarthrosis, and imaging definitions of fusion. CONCLUSION: Differentiating between pseudoarthrosis and arthrodesis in the postoperative spine is complex, and requires a robust understanding of various findings across many different modalities.

Beyond plaque: A pictorial review of non-atherosclerotic abnormalities of extracranial carotid arteries.

The common carotid artery (CCA) and extracranial internal carotid artery are subject to a wide variety of non-atheromatous pathologies. These entities are often overshadowed in both research and clinical realms by atherosclerotic disease. Nevertheless, non-atherosclerotic disease of the carotid arteries may have profound, even devastating, neurologic consequences. Hence, this review will cover both common and uncommon forms of extracranial carotid artery pathologies in a pictorial format, in order to aid the diagnostician in identifying and differentiating such pathologies.

The Central Dot Sign : A Specific Post-gadolinium Enhancement Feature of Intramedullary Spinal Cord Metastases.

PURPOSE: Peripheral enhancement characteristics on magnetic resonance imaging (MRI), namely the rim and flame signs, are specific for intramedullary spinal cord metastases (ISCM) compared to primary cord masses. The study compared the frequency of a novel finding-the central dot sign-in ISCMs versus primary intramedullary masses. METHODS: In this study 45 patients with 64 ISCMs and 64 control patients with 64 primary intramedullary cord masses were investigated and 2 radiologists blinded to lesion type independently evaluated MR images for the presence of a central dot sign: a punctate focus of enhancement in/near the center of an enhancing intramedullary mass. The frequency of this sign in the two patient groups was compared. RESULTS: A total of 63 enhancing ISCMs in 44 patients and 54 enhancing primary cord masses in 54 patients were included. The central dot sign was identified in 6% (4/63) of enhancing ISCMs in 9% (4/44) of patients and in none (0/54) of the enhancing primary cord masses (p = 0.038, per patient). The specificity for diagnosing ISCMs among spinal cord masses was 100%. The central dot sign was present in the axial plane only in two ISCMs and in the axial and sagittal planes in two ISCMs. The two ISCMs harboring the central dot sign also demonstrated both the previously described rim and flame signs, and two also demonstrated the rim sign alone. CONCLUSION: The central dot sign is not sensitive but highly specific for ISCMs compared to primary spinal cord masses. The rim and/or flame signs may or may not be concurrently present in ISCMs.

Dynamic Internal Jugular Vein Compression by Hypertrophic Hyoid Bone: Management and Outcomes.

Extracranial osseous compression of the internal jugular vein (IJV) is exceedingly rare. The clinical manifestations of IJV obstruction are very heterogeneous and subtle, and arriving at a diagnosis can be challenging. We describe a case of dynamic IJV compression in a 40-year-old male with progressive, positional, ill-defined right periorbital and neck pain associated with photosensitivity. Imaging showed a hypertrophic right hyoid bone; computed tomography venogram (CTV) with challenging maneuvers demonstrated dynamic compression of the ipsilateral IJV by a hypertrophied hyoid bone and thyroid cartilage. The patient underwent decompression of the right jugular vein which resulted in the resolution of his symptoms. The clinical manifestations of extracranial IJV impingement are variable and diagnostically challenging. Disturbances in extracranial IJV outflow is a diagnosis of exclusion and could be responsible for atypical facial pain in a select group of patients. This entity should be considered in the differential of atypical facial, especially when symptoms tend to be positional.

Synovial Cysts Confounding Access to the Dorsal S1 Neural Foramen in Transforaminal Epidural Steroid Injections.

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.

Aneurysm morphology in patients with autosomal dominant polycystic kidney disease: A case-control study.

PURPOSE: Approximately 8% of patients with autosomal dominant polycystic kidney disease (ADPKD) develop intracranial aneurysms. The reason for development of intracranial aneurysms in ADPKD patients might be related to interactions between the presence of hypertension and the basic mechanism underlying the disease, which leads to weakness of the connective tissue. In this study, we aimed to identify differences in aneurysm morphology between ADPKD patients and a location-matched set of controls. METHODS: A total of 42 ADPKD patients and 49 control patients with 122 aneurysms were included. Aneurysm size, location, and morphology were evaluated by two neuroradiologists. Aneurysm morphology was classified into one of three groups: regular saccular, irregular saccular, and fusiform. Continuous variables were compared with chi-squared tests and categorical variables were compared with student's t-test. RESULTS: When considering all patients, there was no significant difference in aneurysm morphology or size (4.5 ±â€¯2.6 mm vs 5.4 ±â€¯2.9 mm; p = 0.09) between the ADPKD and control group. In a subgroup analysis of medium and large aneurysms (n = 61), there was a significantly lower incidence of regular saccular aneurysms (28% vs. 56%; p = 0.03) and higher incidence of fusiform aneurysms (12% vs 0%; p = 0.03) in the ADPKD group compared to a control group. CONCLUSION: When excluding categorically "small" aneurysms, there is a reduced incidence of regular saccular aneurysms and increased incidence of fusiform aneurysms in ADPKD patients compared to a control group. Further study of this population of patients is warranted to better understand their risks of aneurysm rupture and indications for treatment.

The Impact of Social Media on Negative Online Physician Reviews: an Observational Study in a Large, Academic, Multispecialty Practice.

BACKGROUND: Online reviews of physicians are becoming increasingly common, however no correlation of these reviews to formal patient satisfaction surveys. With the explosion of social media, it is unknown as to how this form of communication may have a role in potentially managing and addressing the search position of negative online reviews. METHODS: We obtained a list of 102 physicians with negative online reviews between September 2014 and December 2014. Social media uptake and average Google search position of the physician and their respective negative online reviews were assessed from January 2015 through January 2017. RESULTS: Fifty-four (53%) physicians had any social media presence in January 2015. All 102 physicians were subsequently offered social media coaching by the Mayo Clinic Center for Social Media which resulted in an increase to 90% of these physicians participating in social media by January 2017. The average Google search position for the negative online reviews was significantly reduced from 5.2 ± 2.5 to 14.3 ± 11.3 (P < 0.001) from 2015 to 2017. There was a moderate increase in Doximity uptake during that time increasing from 11% of the physicians having a claimed profile to 80%. There were non-significant reductions in the average Google search position - 9.7 ± 11.3 in the physicians who had an existing a social media presence versus those who were not on social media - 4.2 ± 2.2 (P = 0.11). CONCLUSIONS: Physician social media presence can reduce the bearing of negative online comments by decreasing the search position of these comments.

Online Physician Reviews Do Not Reflect Patient Satisfaction Survey Responses.

Online physician reviews have become increasingly prevalent and are a common means by which patients explore medical options online. Currently, there are no data comparing physicians with negative online reviews and those without negative reviews. We sought to compare industry-vetted patient satisfaction surveys (PSSs), such as Press Ganey (PG) PSSs, between those physicians with negative online reviews and those without negative reviews. Overall, there were 113 unique individuals with negative online reviews from September 1, 2014, to December 31, 2014, with 8 being nonphysicians. We matched 113 physicians in similar departments/divisions. We obtained PG PSS scores of both groups and compared the mean scores of the 2 groups. Press Ganey PSS scores were available for 98 physicians with negative online reviews compared with 82 matched physicians without negative online reviews. The mean raw PG PSS scores were not different between the 2 groups (4.05; 95% CI, 3.99-4.11 vs 4.04; 95% CI, 3.97-4.11; P=.92). We also noted no difference in mean scores on questions related to physician-patient communication and interaction skills between those with poor online reviews and those without (4.38; 95% CI, 4.32-4.43 vs 4.41; 95% CI, 4.35-4.47; P=.42). However, there was a significantly lower non-physician-specific mean in those with negative online reviews (3.91; 95% CI, 3.84-3.97) vs those without negative online reviews (4.01; 95% CI, 3.95-4.09) (P=.02). Here, we provide data indicating that online physician reviews do not correlate to formal institutional PG PSS. Furthermore, physicians with negative online reviews have lower scores on non-physician-specific variables included in the PG PSSs, emphasizing that these discrepancies can negatively affect overall patient experience, online physician reviews, and physician reputation. It is prudent that an improved mechanism for online ratings be implemented to better inform patients about a physician's online reputation.

Hemodynamic characteristics of stable and unstable vertebrobasilar dolichoectatic and fusiform aneurysms.

BACKGROUND AND PURPOSE: Vertebrobasilar dolichoectatic and fusiform aneurysms (VBDAs) are known to have a poor natural history, with high rates of growth, rupture, and stroke. The purpose of this study was to identify hemodynamic characteristics that differ between VBDAs associated with growth, rupture, and stroke. MATERIALS AND METHODS: VBDAs with CT angiography or MR angiography followed longitudinally without treatment were studied. Unstable aneurysms were defined as those that grew or ruptured during follow-up. Aneurysms associated with stroke were defined as those associated with posterior circulation infarct at follow-up. Baseline data, including demographics, comorbidities, and aneurysm morphology and size were collected. Image based computational fluid dynamics models were created and run under pulsatile flow conditions. Relevant hemodynamic and geometric variables were calculated and compared between groups (stable vs unstable and no stroke vs stroke) using the Wilcoxon test. RESULTS: A total of 37 VBDAs were included (24 stable, 13 unstable; 30 no stroke, 7 stroke). Unstable aneurysms had lower shear rates (P=0.05), blood flow velocity (P=0.03), and lower vorticity (P=0.049) than stable aneurysms. In addition, unstable aneurysms had higher mean oscillatory shear indices (P=0.001). There were no differences in the hemodynamic characteristics of aneurysms in the stroke group compared with the non-stroke group. CONCLUSION: This small study suggests there may be hemodynamic differences between unstable and stable VBDAs. Unstable VBDAs appear to be under lower flow conditions with lower velocity, vorticity, and shear rates, and have more oscillatory flow. There was no difference in the hemodynamic characteristics of aneurysms in the stroke and no stroke group.

The Social Media DNA of Mayo Clinic-and Health Care.

Hippocrates' admonition and the medical community's aversion to risk have caused many physicians and institutions to resist participation in modern social media sites such as Facebook (Facebook, Inc, Menlo Park, California, USA), Twitter (Twitter Inc, San Francisco, California, USA), and YouTube (San Mateo, California, USA). However, because Mayo Clinic's founders were champions of analog social networking, it was among the earliest hospitals worldwide to create official accounts on these digital platforms. A proper understanding of the traditional mechanisms of knowledge diffusion in medicine and of the nature of social media sites should help professionals see and embrace the opportunities for positive engagement in social media.

The Strategic Imperative for the Use of Social Media in Health Care.

Although health care lags behind many other industries in adopting social media as part of a business strategy, the Mayo Clinic recognized the importance of these applications more than a decade ago. In addition to typical media relations and marketing tactics, the Mayo Clinic has successfully used social media as part of an overall program to support the strategic imperatives of the institution.

Mayo Clinic Care Network: A Collaborative Health Care Model.

By leveraging its experience and expertise as a consultative clinical partner, the Mayo Clinic developed an innovative, scalable care model to accomplish several strategic goals: (1) create and sustain high-value relationships that benefit patients and providers, (2) foster relationships with like-minded partners to act as a strategy against the development of narrow health care networks, and (3) increase national and international brand awareness of Mayo Clinic. The result was the Mayo Clinic Care Network.

Prevalence of hyperdense paraspinal vein sign in patients with spontaneous intracranial hypotension without dural CSF leak on standard CT myelography.

PURPOSE: A recently identified and treatable cause of spontaneous intracranial hypotension (SIH) is cerebrospinal fluid (CSF)-venous fistula, and a recently described computed tomography myelogram (CTM) finding highly compatible with but not diagnostic of this entity is the hyperdense paraspinal vein sign. We aimed to retrospectively measure the prevalence of the hyperdense paraspinal vein sign on CTMs in SIH patients without dural CSF leak, in comparison with control groups. METHODS: Three CTM groups were identified: 1) SIH study group, which included dural CSF leak-negative standard CTMs performed for SIH, with early and delayed imaging; 2) Early control CTMs, which were performed for indications other than SIH, with imaging shortly after intrathecal contrast administration; 3) Delayed control CTMs, which included delayed imaging. CTMs were retrospectively reviewed for the hyperdense paraspinal vein sign by experienced neuroradiologists, blinded to the group assignment. All CTMs deemed by a single reader to be positive for the hyperdense paraspinal vein sign were independently reviewed by two additional neuroradiologists; findings were considered positive only if consensus was present among all three readers. For positive cases, noncontrast CTs and prior CTMs, if available, were reviewed for the presence of the sign. RESULTS: Seven of 101 (7%) SIH patients had contrast in a spinal/paraspinal vein consistent with the hyperdense paraspinal vein sign; no patient in either control group (total n=54) demonstrated the hyperdense paraspinal vein sign (P = 0.0463). The finding occurred only at thoracic levels. Each patient had a single level of involvement. Six (86%) occurred on the right. Four occurred in female patients (57%). The sign was seen on early images in 3 of 7 cases (43%) and on both early and delayed images in 4 of 7 cases (57%). In 2 of 7 patients (29%), a noncontrast CT covering the relevant location was available and negative for the sign. A prior CTM was available in 2 of 7 patients (29%), and in both cases the hyperdense paraspinal vein sign was also evident. CONCLUSION: The prevalence of the hyperdense paraspinal vein sign in SIH patients with dural CSF leak-negative standard CTM was 7%. As the sign was not seen in control groups, this sign is highly compatible with the presence of CSF-venous fistula. Since the CTMs were not specifically dedicated to identifying hyperdense paraspinal veins (i.e., they were not dynamic and were not preceded by digital subtraction myelography), the true prevalence of the sign may be higher. Radiologists should scrutinize conventional CTMs for this sign, especially in patients in whom a traditional dural CSF leak is not identified.

Penetrating Osseous Spicules Causing High-Flow Ventral CSF Leaks in the Setting of Relatively Low BMI : A Preliminary Study.

OBJECTIVE/BACKGROUND: We have anecdotally observed patients with high-flow ventral cerebrospinal fluid (CSF) leaks resulting from penetrating osseous spicules or calcified discs to be relatively thin. The purpose of this study was to explore the validity of this observation and determine if a potential association exists between low body mass index (BMI) and high-flow spinal ventral CSF leaks resulting from such dura-penetrating lesions. METHODS: Sixteen consecutive patients with precisely localized high-flow ventral spinal CSF leaks on dynamic myelography were identified. The cause of the CSF leak was determined. The BMI on the date nearest to and within 2 weeks of myelography was recorded. Utilizing exact sign test, the body mass index was compared to the average BMI from the National Health and Nutrition Examination Survey (Centers for Disease Control), matched to sex and age-range. RESULTS: The cohort consisted of 10 males (63%) and 6 females with a mean age of 54 years (range 37-72 years). In all patients, a spiculated osteophyte/calcified disc was identified at the site of the leak. Fourteen patients (88%) had a BMI below the matched national average, while only two patients (13%) had values above the national average (p = 0.004). CONCLUSIONS: Patients with high-flow ventral CSF leaks resulting from spiculated osteophyte or calcified disc as identified by dynamic myelography are more likely to have a BMI below the U.S. national average, matched for gender and age-range. This exploratory analysis requires confirmation as well as further characterization of potential pathophysiologic mechanisms and impact on radiographic and clinical assessments.

Prevalence of cerebral cavernous malformations associated with developmental venous anomalies increases with age.

BACKGROUND AND PURPOSE: To test the hypothesis that the prevalence of cerebral cavernous malformation (CCM) associated with developmental venous anomalies (DVAs) increases with age, we studied the age-related prevalence of DVA-associated CCM among patients with DVAs. MATERIALS AND METHODS: Patients with DVAs on contrast-enhanced MRI exams performed over a 2-year period were included in this study. A single neuroradiologist reviewed all imaging exams for the presence of CCMs. Baseline demographic data collected included age, gender, presence of CNS neoplasm, history of cranial radiation, and history of seizure. Patients were divided into age groups based on decade of life. Cochran-Armitage trend tests were performed to determine if increasing age was associated with CCM prevalence. RESULTS: A total of 1689 patients with DVAs identified on contrast-enhanced MRI were included. Of these patients, 116 (6.9%) had a cavernous malformation associated with the DVA. There was a significant positive association between age and the prevalence of DVA-associated CCM (P = 0.002). The prevalence of DVA-associated CCM was 0.8% for the 0-10 age group, 1.6% for the 11-20 age group, 7.5% for the 21-30 age group, 9.5% for the 31-40 age group, 6.1% for the 41-50 age group, 6.3% for the 51-60 age group, 7.4% for the 61-70 age group, and 11.6% for the >70 age group (P < .0001). CONCLUSIONS: Our study demonstrated an age-related increase in prevalence of DVA-associated cavernous malformations among patients with DVAs. These findings suggest that DVA-associated cavernous malformations are acquired lesions.

Imaging Appearance of Advanced Chronic Adhesive Arachnoiditis: A Retrospective Review.

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.

Prevalence of Developmental Venous Anomalies Increases With Age.

BACKGROUND AND PURPOSE: To test the hypothesis that developmental venous anomalies (DVAs) may develop in the postnatal period, we studied the age-related prevalence of DVAs on contrast-enhanced magnetic resonance imaging. METHODS: Reports from a consecutive series of head magnetic resonance images with intravenous contrast performed over a 2-year period at our institution were reviewed. Studies reporting the presence of a DVA were retrieved and reviewed by a neuroradiologist. Patients were divided into 4 age groups: (1) <1 year old (neonates/infants), (2) 1 to 5 years old (toddlers and preschoolers), (3) 6 to 17 years old (grade schoolers), and (4) ≥18 years old (adults), and DVA prevalence by age group was studied. RESULTS: A total of 18 073 individuals were included. DVA prevalence in the neonate/infant age group was 1.5% (5/335) compared with 7.1% (51/714) in the toddler/preschool age group. In both the grade-school age group and adult age group, DVA prevalence was 9.6% (150/1557 and 1483/15 467, respectively). Neonates/infants were significantly less likely to have DVAs than other age groups (P<0.001). CONCLUSIONS: We found a very low prevalence of DVAs on contrast-enhanced magnetic resonance imaging in patients <1 year old which was significantly lower than other age groups. These findings suggest that postnatal changes in venous architecture and drainage patterns may contribute to the development of DVAs.

Association between imaging findings and microbiological findings for image­guided biopsies for spine infections.

BACKGROUND: In the evaluation of spondylodiscitis, a number of factors are thought to contribute to the positive­predictive­value of spine biopsy including biopsy technique and equipment, number of sample obtained, timing of antibiotics, imaging findings and lab values. The purpose of this study was to examine which technical, magnetic resonance imaging (MRI), laboratory and clinical findings are most frequently associated with positive cultures or histopathology among patients receiving spine biopsies with a focus on the association of imaging findings and positive cultures/histopathology. METHODS: Following International Review Board approval, we retrospectively reviewed a consecutive series of spine biopsies performed at our institution over a 28-month period in patients who received spine biopsies for radiographically and clinically suspicious spondylodiscitis. All patients underwent MRI prior to biopsy. Patient charts were reviewed for the following data: erythrocyte sedimentation rate (ESR), C­reactive protein (CRP), and white blood cell level at the time of biopsy, prior back surgeries, timing of last dose of antibiotics prior to biopsy, and length of antibiotic therapy prior to biopsy. We also reviewed procedure notes from the biopsy and collected the following data: technique (transpedicular versus parapedicular), equipment used, type of imaging guidance (CT versus fluoroscopy) and number of samples obtained. MRI studies were evaluated by two radiologists and rated on an ordinal 1-4 scale based on increasing suspicion for spondylodiscitis (1 lowest, 4 highest). All categorical variables were compared using chi­squared tests. All continuous variables were compared using Student's t­tests. RESULTS: Seventy­seven patients are included in this study. Overall, 62% (48/77) were positive for infection on pathological and/or microbiological studies. There was a significant association between radiological index of suspicion and biopsy positivity as 0% (0/3) with index of 1, 31% (4/13) with an index of 2, 59% (10/17) with an index of 3 and 83% (30/36) with an index of 4 had positive pathology (P=0.001). Biopsy approach, type of imaging guidance, CBC, and number of passes were not associated with biopsy positivity. Elevated CRP was associated with biopsy positivity (P=0.002) while elevated ESR was not (P=0.12). On multivariate analysis adjusting for the MRI scale, ESR and CRP, increasing degree of suspicion on MRI was independently associated with biopsy positivity (P<0.01) while CRP and ESR were not independently associated with biopsy positivity. CONCLUSIONS: In this study of 77 patients receiving spinal biopsy for diagnosis of spondylodiscitis, a high index of suspicion based on MRI imaging was strongly associated with positive biopsy samples on culture and/or histopathology. In addition, imaging findings were independently associated with positive biopsy findings while elevated CRP and ESR were not. These findings suggest that MRI findings should be used to guide practitioners in their pursuit of a causative organism among patients with suspected discitis­osteomyelitis.