Magnetic resonance imaging of bacterial and tuberculous spondylodiscitis with associated complications and non-infectious spinal pathology mimicking infections: a pictorial review

The Need for Comprehensive Medical Management in Pyogenic Spondylodiscitis: A Review Article

The incidence of spontaneous or primary spondylodiscitis has been increasing over the years, affecting the aging population with multiple comorbidities. Several conditions influencing treatment outcomes stand out, such as diabetes mellitus, renal insufficiency, cardiovascular and respiratory dysfunction, and malnutrition. Due to these, the question arises regarding properly managing their current conditions and pre-existing disease states. Treatment plans must consider all concomitant comorbidities rather than just the infectious process. This can be done with the help of multidisciplinary teams to provide comprehensive care for patients with pyogenic spondylodiscitis. To date, there is no article regarding comprehensive medicine for spontaneous pyogenic spondylodiscitis; hence, this paper reviews the evidence available in current literature, recognizes knowledge gaps, and suggests comprehensive care for treating patients with spinal infections. Pre-requisites for implementing multidisciplinary teams include leadership, administrative support, and team dynamics. This group comprises an appointed leader, coordinator, and different subspecialists, such as orthopedic surgeons, infectious disease specialists, internists, rehabilitation doctors, psychiatrists, microbiologists, radiologists, nutritionists, pharmacologists, nurses, and orthotists working together with mutual trust and respect. Employing collaborative teams allows faster time for diagnosis and improves clinical outcomes, better quality of life, and patient satisfaction. Forefront communication is clear and open between all team members to provide holistic patient care. With these in mind, the need for employing multidisciplinary teams and the feasibility of its implementation emerges, showing a promising and logical path toward providing comprehensive care in managing multimorbid patients with pyogenic spondylodiscitis.

Imaging of Spondylodiscitis: A Comprehensive Updated Review-Multimodality Imaging Findings, Differential Diagnosis, and Specific Microorganisms Detection

Spondylodiscitis is defined by infectious conditions involving the vertebral column. The incidence of the disease has constantly increased over the last decades. Imaging plays a key role in each phase of the disease. Indeed, radiological tools are fundamental in (i) the initial diagnostic recognition of spondylodiscitis, (ii) the differentiation against inflammatory, degenerative, or calcific etiologies, (iii) the disease staging, as well as (iv) to provide clues to orient towards the microorganisms involved. This latter aim can be achieved with a mini-invasive procedure (e.g., CT-guided biopsy) or can be non-invasively supposed by the analysis of the CT, positron emission tomography (PET) CT, or MRI features displayed. Hence, this comprehensive review aims to summarize all the multimodality imaging features of spondylodiscitis. This, with the goal of serving as a reference for Physicians (infectious disease specialists, spine surgeons, radiologists) involved in the care of these patients. Nonetheless, this review article may offer starting points for future research articles.

Magnetic resonance imaging features for differentiating tuberculous from pyogenic spondylitis: a meta-analysis

OBJECTIVE

To perform a meta-analysis comparing the MRI features of tuberculous and pyogenic spondylitis, using histopathological results and/or blood culture as the standard reference.

MATERIALS AND METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched for English-language studies on the MRI features of tuberculous and pyogenic spondylitis published between January 2010 and February 2023. Risk for bias and concerns regarding applicability were assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Pooled MRI features' proportions were calculated using a bivariate random-effects model.

RESULTS

Thirty-two studies met the inclusion criteria: 21 for tuberculous spondylitis, three for pyogenic spondylitis, and eight for both. Of the nine informative MRI features comparing tuberculous spondylitis to pyogenic spondylitis, involvement of ≥ 2 vertebral bodies (92% vs. 88%, P = .004), epidural extension (77% vs. 25%, P < .001), paravertebral collection (91% vs. 84%, P < .001), subligamentous spread (93% vs. 24%, P < .001), thin and regular abscess wall (94% vs. 18%, P < .001), vertebral collapse (68% vs. 24%, P < .001), and kyphosis (39% vs. 3%, P < .01) were more suggestive of tuberculous spondylitis, while disc signal change (82% vs. 95%, P < .001) and disc height loss (22% vs. 59%, P < .001) were more suggestive of pyogenic spondylitis.

CONCLUSION

Involvement of ≥ 2 vertebral vertebral bodies, soft tissue attribution, thin and regular abscess wall, vertebral collapse, and kyphosis were MRI features more common in tuberculous spondylitis, while disc signal change and height loss were more common in pyogenic spondylitis.

Spondylodiscitis: A Diagnostic and Management Dilemma

Aims Spondylodiscitis (SpD), a debilitating infective condition of the spine, mandates early diagnosis and institution of appropriate therapy, for which accurate microbiology and histological evaluation of the affected tissue is vital. The objectives of the study were to assess the correlation between clinical and magnetic resonance imaging (MRI) findings with histopathology (HPE) and microbiology (MB) in clinically diagnosed spondylodiscitis. Settings and design This was a prospective study of 34 consecutive patients reporting at the outpatient department of a tertiary hospital with clinical and imaging features of SpD, who underwent image-guided/surgical biopsy of lesions. Methods and material The provisional diagnosis of SpD in all patients was made on the combined basis of clinical profile and MRI Spine findings. Tissue samples in all patients, obtained by either open surgery or CT-guided biopsy, were subjected to HPE and MB analysis.  Results SpD has a bimodal age distribution with the majority of patients being males in the fourth to fifth decades. Only raised erythrocyte sedimentation rate (ESR) was consistently seen amongst laboratory parameters, with leucocytosis being added pointer towards pyogenic etiology. MRI remained the imaging modality of choice for SpD but was not dependable for etiologic differentiation. On HPE and MB evaluations, 24 patients (71%) had findings consistent with infective SpD, while combined results augmented etiologic confirmation for 28 patients (82.4%). HPE was more sensitive than traditional MB methods to determine etiology in SpD, but the addition of the GeneXpert (Cepheid, Sunnyvale, California, United States) technique improved the MB positivity rate, especially in patients with tubercular SpD. Six patients (17.6%) with both negative HPE and MB results were categorized as 'Non-specific' SpD. Conclusions SpD poses a challenge to determine the etiology for the administration of specific antimicrobial therapy. A stratified standard institutional approach needs adoption to systematically evaluate SpD patients by having a high index of clinical suspicion, early imaging, followed by tissue biopsy for HPE and MB. Despite efforts to reach a diagnosis, a subset of patients without conclusive etiologic agent identification would remain as 'Non-specific', needing empiric antibiotic treatment based on clinico-radiologic profile.

The advancement of MRI in differentiating Modic type I degenerative changes from early spinal infections

MRI is the most sensitive and specific imaging method for the detection of advanced spinal infections. However, the differential diagnosis of early spinal infection and Modic Type I degenerative changes based on conventional MRI is difficult clinically, as they both may mimic each other by showing hypointensity on T1 weighted images and hyperintensity on T2 weighted spine MRI images. This review summarizes recent advancements in MRI, which may be useful in discriminating degenerative Modic Type I endplate changes from early spinal infection, and evaluates the diagnostic accuracy and limitations of MRI. We aim to provide indications for early differential diagnosis to help initiate appropriate treatment in a timely manner so that associated complications can be avoided.

Discitis-osteomyelitis: optimizing results of percutaneous sampling

Vertebral discitis-osteomyelitis is an infection of the spine that involves the intervertebral disc and the adjacent vertebral body but may also extend into the paraspinal and epidural soft tissues. If blood cultures and other culture data fail to identify a causative microorganism, percutaneous sampling is indicated to help guide targeted antimicrobial therapy. Despite limited supporting evidence, withholding antimicrobial therapy for up to 2 weeks is recommended to maximize microbiological yield, although literature supporting this recommendation is limited. During the procedure, technical factors that may improve yield include targeting of paraspinal fluid collections or soft tissue abnormalities for sampling, acquiring multiple core samples if possible, and use of larger gauge needles when available. Repeat sampling may be indicated if initial percutaneous biopsy is negative but should be performed no sooner than 72 h after the initial percutaneous biopsy to ensure adequate time for culture results to return.

Imaging of the Craniocervical Junction: A Pictorial Review

The craniocervical junction (CCJ) is a complex anatomical structure comprising the occiput, the atlas, and the axis. The CCJ plays an important role in maintaining stability, providing protection, and supporting neurovascular structures. The CCJ can be affected by a wide range of congenital variants and traumatic, degenerative, inflammatory, and tumoral pathologies. This pictorial review the normal anatomy of the CCJ and presents the most common anatomical variants and pathologic conditions affecting the CCJ.

Tuberculosis of the spine

Pott's spine, commonly known as spinal tuberculosis (TB), is an extrapulmonary form of TB caused by Mycobacterium TB. Pott's paraplegia occurs when the spine is involved. Spinal TB is usually caused by the hematogenous spread of infection from a central focus, which can be in the lungs or another location. Spinal TB is distinguished by intervertebral disc involvement caused by the same segmental arterial supply, which can result in severe morbidity even after years of approved therapy. Neurological impairments and spine deformities are caused by progressive damage to the anterior vertebral body. The clinical, radiographic, microbiological, and histological data are used to make the diagnosis of spinal TB. In Pott's spine, combination multidrug antitubercular therapy is the basis of treatment. The recent appearance of multidrug-resistant/extremely drug-resistant TB and the growth of human immunodeficiency virus infection have presented significant challenges in the battle against TB infection. Patients who come with significant kyphosis or neurological impairments are the only ones who require surgical care. Debridement, fusion stabilization, and correction of spinal deformity are the cornerstones of surgical treatment. Clinical results for the treatment of spinal TB are generally quite good with adequate and prompt care.

Imaging of Spondylodiscitis: An Update

Spondylodiscitis is an infection of the vertebral body and/or intervertebral disc, which can also involve the epidural space, posterior elements, and paraspinal soft tissues. Due to high morbidity and mortality, prompt diagnosis and treatment of spondylodiscitis is critical. However, diagnosis can be challenging due to nonspecific signs and symptoms. Magnetic resonance imaging with and without contrast is the imaging modality of choice due to high sensitivity and specificity. Intravenous administration of gadolinium contrast can better demonstrate the extent of soft tissue and bone abscesses. However, magnetic resonance imaging is less useful in the evaluation of treatment response. When magnetic resonance imaging cannot be performed or is not diagnostic, radionuclide imaging is a useful alternative. Although bone scintigraphy frequently is used as a screening test, false negative results can occur early in the course of the infection and in the elderly. This test is not useful for detecting the soft tissue infections that often accompany or mimic spondylodiscitis. Gallium-67 citrate improves the specificity of the bone scan, can detect infection earlier than the bone scan, may be more sensitive, especially in elderly patients, and identifies accompanying soft tissue infection. Performing SPECT and SPECT/CT improve accuracy. The 2-3 day delay between radiopharmaceutical administration, poor image quality, and relatively high patient radiation dose are significant disadvantages of gallium-67. Furthermore gallium-67 is no longer as readily available as it once was. ¹⁸F-FDG imaging is the radionuclide test of choice for spondylodiscitis. The procedure, completed in one day, is sensitive, has a high negative predictive value, and reliably differentiates degenerative from infectious vertebral body end-plate abnormalities. ¹⁸F-FDG has outperformed bone and gallium-67 imaging in comparative studies. ¹⁸F-FDG may be able to provide an objective means for monitoring response to treatment. The potential of other agents for diagnosing spondylodiscitis has been studied. Although indium-111biotin accurately diagnoses spondylodiscitis, this radiopharmaceutical has never been commercially available. Gallium-68 citrate and ^99mTc-radiolabeled antimicrobial peptides have been investigated, but their role in the diagnosis of spondylodiscitis has not been established. Labeled leukocyte scintigraphy has no role in the diagnosis of spondylodiscitis.

Differentiating Magnetic Resonance Images of Pyogenic Spondylitis and Spinal Modic Change Using a Convolutional Neural Network

STUDY DESIGN

A retrospective analysis of magnetic resonance imaging (MRI).

OBJECTIVE

The study aimed to evaluate the performance of a convolutional neural network (CNN) to differentiate spinal pyogenic spondylitis from Modic change on MRI. We compared the performance of CNN to that of four clinicians.

SUMMARY OF BACKGROUND DATA

Discrimination between pyogenic spondylitis and spinal Modic change is crucial in clinical practice. CNN deep-learning approaches for medical imaging are being increasingly utilized.

METHODS

We retrospectively reviewed MRIs from pyogenic spondylitis and spinal Modic change patients. There were 50 patients per group. Sagittal T1-weighted (T1WI), sagittal T2-weighted (T2WI), and short TI inversion recovery (STIR) MRIs were used for CNN training and validation. The deep learning framework Tensorflow was used to construct the CNN architecture. To evaluate CNN performance, we plotted the receiver operating characteristic curve and calculated the area under the curve. We compared the accuracy, sensitivity, and specificity of CNN diagnosis to that of a radiologist, spine surgeon, and two orthopedic surgeons.

RESULTS

The CNN-based area under the curves of the receiver operating characteristic curve from the T1WI, T2WI, and STIR were 0.95, 0.94, and 0.95, respectively. The accuracy of the CNN was significantly greater than that of the four clinicians on T1WI and STIR (P<0.05), and better than a radiologist and one orthopedic surgeon on the T2WI (P<0.05). The sensitivity was significantly better than that of the four clincians on T1WI and STIR (P<0.05), and better than a radiologist and one orthopedic surgeon on the T2WI (P<0.05). The specificity was significantly better than one orthopedic surgeon on T1WI and T2WI (P<0.05) and better than both orthopedic surgeons on STIR (P<0.05).

CONCLUSION

We differentiated between Modic changes and pyogenic spondylitis using a CNN that interprets MRI. The performance of the CNN was comparable to, or better than, that of the four clinicians.

Detection of Spinal Tuberculosis by F-18 FDG PET/CT as a Cause of Unusual Referred Pain in the Right Upper Quadrant of Abdomen

Tuberculous involvement of the spine (tuberculosis [TB] spine) can cause severe morbidity unless detected and treated early. Apart from the constitutional symptoms, it can present with back pain, kyphosis, gait abnormality, and paraplegia secondary to the bone or spinal cord involvement. There had been instances of TB spine presenting directly as abdominal pain due to psoas abscesses. Herein, we report a very rare clinical manifestation of TB spine as referred pain in the right upper abdominal quadrant due to right epidural phlegmon associated with T7 vertebra, detected by positron emission tomography.

Atlantoaxial instability and cervical noninfectious spondylodiscitis in a patient with Wegener’s granulomatosis: A case report

A 61‐year‐old male patient with Wegener's granulomatosis was admitted due to neck pain and quadriparesis. Clinical evaluation showed severe cervical noninfectious spondylodiscitis, myelopathy, sagittal imbalance, and atlantoaxial instability. A combined anterior and posterior approach was implemented. Postoperative clinical evaluation showed improved neurologic status.

A Review of Posteromedial Lesions of the Chest Wall: What Should a Chest Radiologist Know?

A heterogeneous group of tumors can affect the posteromedial chest wall. They form diverse groups of benign and malignant (primary or secondary) pathologies that can arise from different chest wall structures, i.e., fat, muscular, vascular, osseous, or neurogenic tissues. Chest radiography is very nonspecific for the characterization of chest wall lesions. The modality of choice for the initial assessment of the chest wall lesions is computed tomography (CT). More advanced cross-sectional modalities such as magnetic resonance imaging (MRI) and positron emission tomography (PET) with fluorodeoxyglucose are usually used for further characterization, staging, treatment response, and assessment of recurrence. A systematic approach based on age, clinical history, and radiologic findings is required for correct diagnosis. It is essential for radiologists to be familiar with the spectrum of lesions that might affect the posteromedial chest wall and their characteristic imaging features. Although the imaging findings of these tumors can be nonspecific, cross-sectional imaging helps to limit the differential diagnosis and determine the further diagnostic investigation (e.g., image-guided biopsy). Specific imaging findings, e.g., location, mineralization, enhancement pattern, and local invasion, occasionally allow a particular diagnosis. This article reviews the posteromedial chest wall anatomy and different pathologies. We provide a combination of location and imaging features of each pathology. We will also explore the role of imaging and its strengths and limitations for diagnosing posteromedial chest wall lesions.

99mTc-ethambutol scintigraphy with single-photon emission computed tomography/computed tomography in vertebral tuberculosis

Vertebral tuberculosis (TB) is a common form of extrapulmonary TB. Here, the slow-growing Mycobacterium bacillus reaches the disc space through the hematogenous route and leads to various complications. Radiological imaging and histopathology have been the mainstay of diagnosis, but radionuclide imaging techniques using radiolabeled antitubercular drugs have rarely found space in the clinical domain. Here, we present a case of vertebral TB, where a technetium-labeled antitubercular drug, ethambutol, was synthesized and used for imaging the bacteria in vivo. Thus, we demonstrate a rarely used potentially specific agent for tuberculous-infection imaging, which can be produced in-house, and provides rapid results.

MRI Features Associated With the Detection of Microbial Pathogens by CT-Guided Biopsy in Septic Spondylodiscitis

OBJECTIVE

The aim of this study was to assess the magnetic resonance imaging (MRI) features associated with microbial pathogen detection by computed tomography (CT)-guided biopsy in patients with suspected septic spondylodiscitis.

METHODS

For the last 10-year period, we analyzed the medical records of patients who underwent MRI and CT-guided biopsy for suspected septic spondylodiscitis. Clinical characteristics were recorded. The following MRI features were assessed: edema or contrast enhancement of the intervertebral disc, adjacent vertebrae, epidural and paravertebral space, presence of abscess, and paravertebral edema size. A positive biopsy was defined by pathogen identification on bacterial analysis or the presence of granuloma on histology. Predictors of a positive biopsy were assessed with a logistic regression model.

RESULTS

We examined data for 61 patients (34 [56%] male; mean age, 59.9 ± 18.0 years); for 35 patients (57%), CT-guided biopsy was positive for a pathogen. The 4 MRI findings significantly associated with a positive biopsy were epiduritis, greater than 50% vertebral endplate edema, loss of intradiscal cleft, and abscess. The size of paravertebral edema was greater with a positive than negative biopsy (median, 15.9 [interquartile range, 11.3-21.3] vs 7.3 [4.6-12.9] mm; p = 0.004). On multivariable analysis, epiduritis was the only independent predictor of a positive biopsy (adjusted odds ratio, 7.4 [95% confidence interval, 1.7-31.4]; p = 0.006).

CONCLUSIONS

Epiduritis and the size of paravertebral edema on MRI are associated with detection of a microbial pathogen in suspected septic spondylodiscitis. For patients without these MRI signs, the need for further investigations such as enriched or prolonged cultures, a second CT-guided biopsy, or even surgical biopsy need to be discussed.

MORPHOLOGICAL ASPECT OF PYOGENIC SPINAL EPIDURAL ABSCESSES. PART I

ABSTRACT Background: Pyogenic Spinal Epidural Abscess (PSEA) is difficult to diagnose and can have devastating consequences. Magnetic Resonance Imaging (MRI) has high sensitivity and specificity, which are further increased with the use of contrast. There are several classifications of vertebral infectious processes, with emphasis on spondylodiscitis. Objective: To analyze the morphological parameters and their reproducibility; and to analyze different resonance imaging sequences. Methods: Using an image database, a morphological classification of PSEA was planned, with five parameters: Region (R), indicating the upper and lower limits of the abscess; Location (U), indicating whether the abscess is anterior or posterior within the canal; Compromise (C), meningeal or content of the structures; Association (A), discitis, osteomyelitis or both; and Perivertebral (P), anterior, lateral or posterior extravertebral abscess. The first three parameters give an idea of the volume of the PSEA, while the last two give the related infectious foci. Thirty-five cases were analyzed using Kappa’s coefficient. Results: The global intra- and interobserver reproducibility was Kappa 0.81. The results for each parameter were as follows: R=0.95, U=0.92, C=0.66, A=0.70 and P=0.80. The first three give a notion of volume and the last two relate to the presence of vertebral infectious foci outside the canal. T2 weighted MRI with contrast was found to be the most effective imaging sequence. Conclusion: The morphological classification is simple to use, with excellent reproducibility. The parameters with the highest reproducibility were region and location, with values >0.92. The addition of gadolinium contrast increased the sensitivity of the diagnosis; the use of sagittal and axial images in T2-MRI was the most sensitive imaging sequence. Evidence Level III; Original.

Spinal disorders mimicking infection

Spinal infections are very commonly encountered by radiologists in their routine clinical practice. In case of typical MRI features, the diagnosis is relatively easy to interpret, all the more so if the clinical and laboratory findings are in agreement with the radiological findings. In many cases, the radiologist is able to make the right diagnosis, thereby avoiding a disco-vertebral biopsy, which is technically challenging and associated with a risk of negative results. However, several diseases mimic similar patterns, such as degenerative changes (Modic) and crystal-induced discopathy. Differentiation between these diagnoses relies on imaging changes in endplate contours as well as in disc signal. This review sought to illustrate the imaging pattern of spinal diseases mimicking an infection and to define characteristic MRI and CT patterns allowing to distinguish between these different disco-vertebral disorders. The contribution of advanced techniques, such as DWI and dual-energy CT (DECT) is also discussed.

Pyogenic and Non-Pyogenic Spinal Infections: Diagnosis and Treatment

Spinal infection (SI) is an infection of vertebral bodies, intervening disc, and/or adjoining para-spinal tissue. It represents less than 10 % of all skeletal infections. There are numerous factors that predispose to developing a SI. Due to the low specificity of signs, delayed diagnosis is common. Hence, SI may be associated with poor outcomes. Diagnosis of SI must be supported by clinicopathological and radiological findings. MRI is a reliable modality of choice. Treatment options vary according to the site of the infection, disease progression, neurology, presence of instability, and general condition of the subject. Conservative treatment (orthosis/ bed-rest + antibiotics) is recommended during the early course with no/ lesser degree of neurological involvement and to medically unfit patients. Nevertheless, when conservative measures alone fail, surgical interventions must be considered. The use of concomitant antimicrobial drugs intravenously during initial duration followed by oral administration is a necessity. Controversies exist regarding the optimal duration of antimicrobial therapy, yet never given less than six weeks. Heterogeneity in clinical picture and associated co-morbidities with a range of treatment modalities are available; however, a common applicable guideline for SI does not exist. Managing SI must be tailored on a case-to-case basis.

Large increase of vertebral osteomyelitis in France: a 2010-2019 cross-sectional study

Vertebral osteomyelitis (VO) represents 4-10% of bone and joint infections. In Western countries, its incidence seems to increase, simultaneously with an increasing number of comorbidities among an ageing population. This study aimed to assess the evolution of VO epidemiology in France over the 2010-2019 decade. A nationwide cross-sectional study was conducted using the French hospital discharge data collected through the French diagnosis-related groups 'Programme de Médicalisation des Systèmes d'Information'. VOs were detected with a previously validated case definition using International Classification of Diseases 10 (ICD-10) codes, implemented with the French current procedural terminology codes. The study population included all patients hospitalised in France during the 2010-2019 decade, aged 15 years old and more. Patient and hospital stay characteristics and their evolutions were described. During the study period, 42 105 patients were hospitalised for VO in France involving 60 878 hospital stays. The mean VO incidence was 7.8/100 000 over the study period, increasing from 6.1/100 000 in 2010 to 11.3/100 000 in 2019. The mean age was 64.8 years old and the sex ratio was 1.56. There were 31 341 (74.4%) patients with at least one comorbidity and 3059 (7.3%) deceased during their hospital stay. Even if rare, device-associated VOs (4450 hospital stays, 7.3%) highly increased over the period. The reliability of the method, based upon an exhaustive database and a validated case definition, provided an effective tool to compare data over time in real-life conditions to regularly update the epidemiology of VO.

MRI in differential diagnosis between tuberculous and pyogenic spondylodiscitis

PURPOSE

The aim of the study was to investigate whether MRI findings together with epidemiological data could help in differentiating between tuberculous and pyogenic spondylodiscitis.

METHODS

Clinical records of 260 patients with a suspicion of spondylodiscitis were analysed. Patients were selected using the following inclusion criteria: confirmed diagnosis of spondylodiscitis either from pyogenic bacteria or from Mycobacterium tuberculosis and contrast-enhanced MRI performed before treatment. Clinical data concerning age, sex and country-of-origin were also collected. For each patient, several MRI-features were evaluated by two-expert musculoskeletal radiologists. A chi-squared test and a multiple logistic regression were used to find the best predictors of tuberculous or pyogenic spondylodiscitis.

RESULTS

114 patients were retrospectively enrolled, 30 with tuberculous and 84 with pyogenic spondylodiscitis. We found 18 MRI-features, significantly different between the two groups. Among these, the most strongly associated with tuberculous spondylodiscitis were: heterogeneous vertebral signal on T1w-sequences (Odds Ratio(OR) = 205.759-p < 0.001), presence of epidural abscess (OR = 86.221-p < 0.001), severe vertebral destruction (OR = 10.017-p < 0.001) and absence of epidural phlegmon (OR = 86.221-p < 0.001). Moreover, patients coming from countries with a middle-high prevalence of tuberculosis were more frequently affected by tuberculous spondylodiscitis than others were (OR = 229.136-p < 0.001). The best prediction model demonstrated a correct classification rate of 94.7%.

CONCLUSION

To the best of our knowledge this is the largest study comparing MRI-features of tuberculous and pyogenic spondylodiscitis. The above-mentioned MRI-features and epidemiological data are crucial in the differential diagnosis between these two entities, guiding the choice of the appropriate therapy, especially when a pathogen cannot be clearly identified with other modalities.

Percutaneous spine biopsy under cone beam computed tomography guidance for spondylodiscitis: Time is diagnosis

BACKGROUND AND PURPOSE

Percutaneous spine biopsies for spondylodiscitis have been long discussed due to the low microbiologic yield. This retrospective study evaluated factors of cone beam computed tomography-guided spine biopsies that may affect microbiologic yield.

METHODS

We retrospectively reviewed percutaneous spine biopsies under cone beam computed tomography for spondylodiscitis performed from January 2015-December 2020. Clinical and technical features such as the time from initial symptoms to biopsy, level biopsied, biopsy needle type/gauge, technical approach, radiation dose, technical success and microbiologic yield were recorded. Pre-procedure magnetic resonance imaging findings were also recorded such as the number of vertebral bodies involved, and disc morphology. Univariate logistic regression analysis and Receiver operating characteristic analysis were performed to assess any relationship between relevant factors and positive cultures.

RESULTS

A total of 50 patients underwent cone beam computed tomography-guided biopsies for spondylodiscitis, with resulted positive cultures in 18 patients (36%). The mean time from the initial referral of spinal symptoms to procedure in the positive culture group was the most influential finding for positive cultures (odds ratio 56.3, p < 0.001). Among magnetic resonance imaging findings, thin or degenerated intervertebral disc was a negative factor for positive cultures (odds ratio 0.09, p = 0.006). Univariate analysis showed that percutaneous approach (transpedicular vs posterolateral/interlaminar) needle size (11-13 g vs 16-18G, odds ratio 1.2, p = 0.7) and site of biopsy (disc vs bone vs disc plus endplate) did not significantly affect the microbiologic yield of spine biopsy.

CONCLUSION

Percutaneous cone beam computed tomography-guided biopsy for spondylodiscitis is a reliable and safe technique and its microbiologic yield may increase if biopsy is performed within the acute phase of infection.

Management of Pyogenic Spondylodiscitis Following Nonspinal Surgeries: A Tertiary Care Center Experience

BACKGROUND

The literature is lacking on the incidence and management of pyogenic spondylodiscitis (PS) following routine elective surgical procedures. This study aimed to analyze the presentation and treatment outcome in patients with PS following nonspinal surgeries at a tertiary care center with a minimum follow-up of 12 months.

METHODS

The demographic, clinical-radiologic features, and treatment outcomes in 40 patients with a diagnosis of PS following nonspinal surgical procedures were retrospectively reviewed and analyzed.

RESULTS

The mean age at presentation was 36.4 ± 11.8 years, with 80% of patients being female. The common surgical procedures associated with PS were cesarean delivery (30%), gastric sleeve surgery (12.5%), and dilatation and curettage (12.5%). The tissue biopsy culture was positive in 82.5% of patients. A total of 26 patients (65%) were treated with conservative management and 14 patients (35%) were treated surgically. The mean pretreatment Core Outcome Measure Index score significantly decreased at 12 months (P < .0001) after treatment. The mean pretreatment erythrocyte sedimentation rate (P < .0001) and C-reactive protein (P < .0001) levels significantly decreased at 12 months after treatment.

CONCLUSIONS

With most patients with PS following nonspinal surgeries treated with conservative management, excellent clinical outcomes were achieved in all patients at 12 months after treatment. The diagnosis of PS should be considered in patients presenting with low back pain (LBP) with a recent history of undergoing a nonspinal surgical procedure. Patients who undergo surgical procedures are an important "at-risk" patient population, and early diagnosis and treatment can help achieve excellent clinical outcomes. Further studies are required to determine risk factors and possible perioperative precautions that can be taken to prevent PS in patients who undergo nonspine surgeries.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Pyogenic spondylodiscitis should be suspected in patients presenting with LBP after a recent non-spinal surgical procedure. Early diagnosis and treatment can help achieve excellent clinical outcomes in these patients.

"Wrap-Around Sign" in Non-Hodgkin Lymphoma of the Spine: A Common yet Overlooked Imaging Feature?

BACKGROUND

Anecdotal cases of the so-called "wrap-around" appearance in non-Hodgkin lymphoma (NHL) of the spine exist in the medical literature. In this paper, we looked at the prevalence of this imaging feature in our institutional cases.

MATERIALS AND METHODS

We screened our institutional database for biopsy-proven NHL. Our inclusion criteria were the histologically confirmed diagnosis of NHL involving any vertebra, available magnetic resonance imaging of the affected site, and a positive wrap-around sign. Exclusion criteria included lymphoma cases without the wrap-around sign and/or histology other than NHL. We subdivided the cases into 3 groups: 1) lymphoma wrapped around the vertebral body; 2) the posterior elements alone; or 3) both the vertebral body and posterior elements.

RESULTS

Our search identified 147 cases of NHL in which a confirmatory biopsy at the primary tumor site was available. Of those, 23 cases fulfilled the inclusion criteria (16 men and 7 women with average age at diagnosis of 63.3 years), yielding prevalence of 15.6% in our series. Most commonly the lymphoma involved the vertebral body with or without some involvement of the posterior vertebral elements (n = 20, 86.9%), followed by posterior vertebral elements (n = 2, 8.7%). One remaining case (4.4%) had lymphoma involving the anterior vertebral body and posterior elements.

CONCLUSIONS

Findings of our pilot study indicated that the wrap-around sign in cases of NHL could be helpful diagnostically. This sign may be frequently under-recognized, leading to potential for a diagnostic dilemma on imaging. Larger studies are necessary to obtain more precise information about the prevalence of the wrap-around sign.

Enzyme-responsive turn-on nanoprobes for in situ fluorescence imaging and localized photothermal treatment of multidrug-resistant bacterial infections

Sensitive diagnosis and elimination of multidrug-resistant bacterial infections at an early stage remain paramount challenges. Herein, we present a gelatinase-responsive turn-on nanoprobe for in situ near-infrared (NIR) fluorescence imaging and localized photothermal treatment (PTT) of in vivo methicillin-resistant Staphylococcus aureus (MRSA) infections. The designed nanoprobe (named AuNS-Apt-Cy) is based on gold nanostars functionalized with MRSA-identifiable aptamer and gelatinase-responsive heptapeptide linker (CPLGVRG)-cypate complexes. The AuNS-Apt-Cy nanoprobe is non-fluorescent in aqueous environments due to the fluorescence resonance energy transfer between the gold nanostar core and cypate dye. We demonstrate that the AuNS-Apt-Cy nanoprobe can achieve MRSA targeting and accumulation as well as gelatinase (overexpressed in MRSA environments)-responsive turn-on NIR fluorescence due to the cleavage of the CPLGVRG linker and localized in vitro PTT via a mechanism involving bacterial cell wall and membrane disruption. In vivo experiments show that the AuNS-Apt-Cy nanoprobe can enable rapid (1 h post-administration) and in situ turn-on NIR fluorescence imaging with high sensitivity (105 colony-forming units) in diabetic wound and implanted bone plate mouse models. Remarkably, the AuNS-Apt-Cy nanoprobe can afford efficient localized PTT of diabetic wound and implanted bone plate-associated MRSA infections under the guidance of turn-on NIR fluorescence imaging, showing robust capability for early diagnosis and treatment of in vivo MRSA infections. In addition, the nanoprobe exhibits negligible damage to surrounding healthy tissues during PTT due to its targeted accumulation in the MRSA-infected site, guaranteeing its excellent in vivo biocompatibility and solving the main bottlenecks that hinder the clinical application of PTT-based antibacterial strategies.

Clinical suspicion of spondylodiscitis with equivocal MRI findings: does diffusion-weighted imaging prove helpful here?

BACKGROUND

Despite the high sensitivity of magnetic resonance imaging (MRI), early detection of spondylodiscitis (SpD) remains challenging due to its low specificity.

PURPOSE

To assess the diagnostic value of diffusion-weighted imaging (DWI) in suspected cases of SpD with ambiguous early MRI findings in the differentiation of degenerative disorders (DD).

MATERIAL AND METHODS

In this prospective study, 52 patients suspected of having SpD underwent a whole-spine 3-T MRI scan comprising sagittal DWI. Of 58 conspicuous, T2-weighted, signal increased discs, 39 were successfully evaluated using DWI. Apparent diffusion coefficient (ADC) values and ADC maps were blindly analyzed using the region of interest of the conspicuous disc and a normal adjacent reference disc. Intraindividual ratios (conspicuous disc: reference disc) were calculated.

RESULTS

All conspicuous discs showed increased absolute ADC values, which did not differ significantly between SpD (n = 22) and DD (n = 17). However, ADC ratio was significantly higher in SpD vs. DD (P < 0.05). In receiver operating characteristic curve analysis, an ADC ratio threshold of 1.6 resulted in 45% sensitivity and 88% specificity (area under the curve = 0.69) for SpD diagnosis.

CONCLUSION

The absolute ADC value does not provide a reliable diagnosis of SpD. Increased diffusivity can be an indication of infection but should always be discussed in the context of existing disc degeneration.

Time to Reconsider Routine Percutaneous Biopsy in Spondylodiscitis?

Percutaneous image-guided biopsy currently has a central role in the diagnostic work-up of patients with suspected spondylodiscitis. However, on the basis of recent evidence, the value of routine image-guided biopsy in this disease can be challenged. In this article, we discuss this recent evidence and also share a new diagnostic algorithm for spondylodiscitis that was recently introduced at our institution. Thus, we may move from a rather dogmatic approach in which routine image-guided biopsy is performed in any case to a more individualized use of this procedure.

Azole-resistant Candida albicans Spondylodiscitis After Bariatric Surgery: A Case Report

CASE

We present a case of azole and partial caspofungin-resistant Candida albicans spondylodiscitis, after bariatric surgery with bowel perforation. Treatment included debridement and several months of anidulafungin, complemented with antibacterial therapy because of relapse for bacterial superinfection. After treatment, the infection did not recur clinically or radiologically during one and half years follow-up.

CONCLUSION

Although C. albicans spondylodiscitis is rare, fungi should be suspected as a causative agent. Adequate history, imaging and laboratory testing, and medical and surgical treatment should be performed to successfully eradicate the infection and resolve potential neurological deficits.

Comparison of the Diagnostic Value of MRI and Whole Body 18F-FDG PET/CT in Diagnosis of Spondylodiscitis

Spondylodiscitis is a spine infection for which a diagnosis by a magnetic resonance imaging (MRI) is considered the most appropriate imaging technique. The aim of this study was to compare the role of an ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and an MRI in this field. For 56 patients with suspected spondylodiscitis for whom MRI and ¹⁸F-FDG PET/CT were performed, we retrospectively analyzed the results. Cohen’s κ was applied to evaluate the agreement between the two techniques in all patients and in subgroups with a different number of spinal districts analyzed by the MRI. Sensitivity, specificity, and accuracy were also evaluated. The agreements of the ¹⁸F-FDG PET/CT and MRI in the evaluation of the entire population, whole-spine MRI, and two-districts MRI were moderate (κ = 0.456, κ = 0.432, and κ = 0.429, respectively). In patients for whom one-district MRI was performed, ¹⁸F-FDG PET/CT and MRI were both positive and completely concordant (κ = 1). We also separately evaluated patients with suspected spondylodiscitis caused by Mycobacterium tuberculosis for whom the MRI and ¹⁸F-FDG PET/CT were always concordant excepting in 2 of the 18 (11%) patients. Sensitivity, specificity, and accuracy of the MRI and ¹⁸F-FDG PET/CT were 100%, 60%, 97%, and 92%, 100%, and 94%, respectively. Our results confirmed the ¹⁸F-FDG PET/CT diagnostic value in the diagnosis of spondylodiscitis is comparable to that of MRI for the entire spine evaluation. This could be considered a complementary technique or a valid alternative to MRI.

Infected Schmorl's node: a case report

Background

Schmorls node (SN) are mostly asymptomatic and incidental findings on MRI. However, sometimes they present like acute onset low back pain or acute exacerbation of chronic back pain after minor trauma.

Case presentation

We present rare case of symptomatic infected SN in 67 years female patient presented with complains of low back pain radiating to right buttock. After initial conservative treatment failed subsequent imaging showed significant increase in size of lesion with focal signal changes in disc space gave suspicion of underlying secondary pathology. Patient operated for complete excision of lesion. Histopathological report was suggestive of pyogenic vertebral osteomyelitis. Patient improved well postoperatively.

Conclusion

Most of the time acute SN responds well to conservative treatment; however rapid deterioration of symptoms or persistent severe pain should give suspicion of underlying secondary pathology.

Vertebral Bone Marrow and Endplate Assessment on MR Imaging for the Differentiation of Modic Type 1 Endplate Changes and Infectious Spondylodiscitis

On magnetic resonance (MR) imaging, Modic type 1 (MT1) endplate changes and infectious spondylodiscitis share similar findings. Therefore, this study investigated vertebral bone marrow and endplate changes to enable their differentiation. The lumbar spine MR examinations of 91 adult patients were retrospectively included: 39 with MT1; 19 with early spondylodiscitis without abscess; and 33 with advanced spondylodiscitis with abscess. The assessment included percentage of bone marrow edema on sagittal short tau inversion recovery images, and the signal ratio of edema to unaffected bone and endplate contour (normal; irregular, yet intact; blurred; destructive) on sagittal unenhanced T1-weighted images. Differences were tested for statistical significance by Chi-square test and mixed model analysis of variance. The MR diagnostic accuracy in differentiating MT1 and spondylodiscitis was assessed by cross-tabulation and receiver-operating characteristic analysis. The endplate contours, edema extents, and T1-signal ratios of MT1 (extent, 31.96%; ratio, 0.83) were significantly different (p < 0.001) from early spondylodiscitis (56.42%; 0.60), and advanced spondylodiscitis (91.84%; 0.61). The highest diagnostic accuracy (sensitivity, 94.87%; specificity, 94.23%; accuracy, 94.51%) in identifying MT1 was provided by an irregular, yet intact endplate contour. This may be a useful MR feature for the differentiation between MT1 and spondylodiscitis, particularly in its early stage.

Recurrent giant cell tumour of the thoracic spine managed by total en bloc spondylectomy and denosumab therapy: a case report

Background

Giant cell tumour (GCT) of the bone is a rare, invasive benign bone tumour, which typically originates in the metaphyseal ends of long bones and rarely in the spine. Here, we report a rare case of recurrent GCT of the thoracic vertebra, which was managed by three-level total en bloc spondylectomy (TES) after denosumab therapy.

Case presentation

A 50-year-old woman presented with a 2-month history of progressive lower back pain. Magnetic resonance imaging revealed destruction of the T11 vertebra and a soft tissue mass. The patient underwent tumour resection. Computed tomography at the 2-year follow-up revealed relapse of the resected tumour, which had spread to the T12 vertebral body. Subsequently, denosumab therapy was administered to the patient for 1 year. The growth of the tumour was controlled, and its boundary line was clear. Thereafter, TES for the T10-T12 vertebrae was performed, and spinal reconstruction was completed through a one-stage single posterior approach. The patient’s condition improved postoperatively, and no evidence of recurrence of GCT of the bone or spinal deformity was observed at the 32-month follow-up.

Conclusions

Denosumab therapy contributed to tumour regression. Three-level TES may be an effective and feasible strategy for managing large recurrent GCTs of the spine after denosumab therapy.

Differentiation between Tuberculous and Pyogenic Spondylodiscitis: The Role of the Anterior Meningovertebral Ligament in Patients with Anterior Epidural Abscess

BACKGROUND AND PURPOSE

Differentiation between tuberculous and pyogenic spondylodiscitis is a diagnostic challenge because imaging often does not reliably distinguish the 2 entities and percutaneous biopsies are often culture-negative. The purpose of this study was to determine whether violation of the anterior meningovertebral ligament in the setting of anterior epidural abscess discriminates between these entities.

MATERIALS AND METHODS

This was a retrospective cohort study of all patients with acid-fast bacillus testing and anterior epidural abscess diagnosed on spinal MR imaging between May 2014 and September 2019, with a final diagnosis of tuberculous or pyogenic spondylodiscitis. Six cases of tuberculous spondylodiscitis (mean age, 45.5 years; 80% male) and 35 cases of pyogenic spondylodiscitis were evaluated (mean age, 56.6 years; 49% male). Demographic characteristics were recorded. Cases were assessed for anterior meningovertebral ligament destruction on MR imaging, as demonstrated by the shape of the epidural collection. Segmental location of the infection was also assessed. Independent 2-sample t tests and χ² tests of independence were performed to evaluate the significance of the difference between the groups.

RESULTS

Five of 6 (83.3%) cases of tuberculous epidural abscess had an intact anterior meningovertebral ligament, and 0/35 cases of pyogenic epidural abscess demonstrated an intact ligament (P < .001). The presence of an intact anterior meningovertebral ligament had 83.3% sensitivity and 100% specificity for tuberculous spondylodiscitis, a 100% positive predictive value, and a 97.2% negative predictive value.

CONCLUSIONS

The presence of an intact anterior meningovertebral ligament has high sensitivity and specificity for tuberculous spondylodiscitis-associated epidural abscess, though these results should be validated in a larger sample.

Computed tomography imaging characteristics help to differentiate pyogenic spondylitis from brucellar spondylitis

PURPOSE

Both pyogenic spondylitis (PS) and brucellar spondylitis (BS) can cause deformities and permanent neurologic deficits without prompt diagnosis and treatment. However, differential diagnosis is challenging. The aim of this study was to compare the computed tomography (CT) imaging features of PS with those of BS.

METHODS

Thirty-two patients with PS and 44 with BS were enrolled in the study. CT images were obtained in all cases. Data on bone destruction and formation, vertebral wall destruction, and osteosclerotic changes were collected and compared using the Chi-square test or t test. A P value < 0.01 was considered statistically significant. Positive predictive values (PPV) for detecting PS or BS were reported.

RESULTS

Involvement of the lumbar vertebrae and multiple spinal levels was more common in the BS group than in the PS group. Bone destruction was significantly greater in the PS group than in the BS group (30.8 vs 18.0%; t = 3.920, P = 0.000), with more extensive destruction of the vertebral body (35.8 vs 12.5%, χ² = 12.672, P = 0.002, PPV = 63.16%). In the BS group, there was more osteosclerosis around erosions (70.5 vs 43.3%, χ² = 11.59, P = 0.001, PPV = 67.74%) and fan-shaped osteosclerosis (27.3 vs 19.4%, χ² = 18.556, P = 0.006, PPV = 64.86%), more bone formation around the vertebra (77.2 vs 34.3%, χ² = 33.608, P = 0.000, PPV = 76.83%), more bone formation under the anterior longitudinal ligament (63.6 vs 19.4%, χ² = 30.133, P = 0.000, PPV = 76.09%), more longer anterior bone formation (3.55 vs 0.78 mm, t = 3.997, P = 0.000), and more anterior and closed-bone formation with local erosion (42.0 vs 9.0%, χ² = 74.243, P = 0.000, PPV = 74.36%).

CONCLUSIONS

CT images have unique advantages of revealing the morphology of erosions, osteosclerosis, and bone formation around the vertebra and help to differentiate PS from BS. These slides can be retrieved under Electronic Supplementary Material.

Misdiagnosed and mismanaged atypical spinal tuberculosis: A case series report

Compared to other diseases, early or atypical spinal tuberculosis (TB) is prone to being misdiagnosed due to the lack of specific clinical manifestations and misleading negative results of various laboratory analyses and imaging examinations. Various methods for diagnosing spinal TB have become research hotspots. Recently, it has been proposed that effective vaccination is a mainstay of long-term policies to combat and control the TB epidemic. However, some new TB vaccines require further evaluation and clinical trials to demonstrate their efficiency and safety. Thus, early diagnosis and effective treatment are the other essential long-term strategies for controlling the TB epidemic immunization is closely associated with the diagnosis of spinal TB, which will become the focus of future research and set the direction for future developments. The present study provides a case series and a literature review of the characteristics of spinal TB to provide guidance for the diagnosis, treatment and prognosis of spinal TB.

Endplate and intervertebral disc injuries in acute and single level osteoporotic vertebral fractures: is there any association with the process of bone healing?

Background

The endplate-intervertebral disc (IVD) complex is closely interrelated with the vertebral body (VB) in the structural integrity of the anterior spinal column, including biomechanical and biological functions. Endplate and IVD injuries are usually found in association with vertebral fractures (VFs); however, little is known about their relevance to the healing of osteoporotic VFs (OVFs). The first purpose of this study was to evaluate the incidence and occurrence pattern of endplate and IVD injuries associated with single- and acute-OVFs, and the second was to evaluate the influence of endplate and IVD injuries on the occurrence of delayed union.

Methods

Endplate and IVD injuries associated with single- and acute-OVFs were retrospectively evaluated using magnetic resonance imaging (MRI). Vertebrae of 168 patients were included in the study. The occurrence rate and type of endplate and IVD injuries were radiologically evaluated, and the association between endplate and IVD injuries was statistically analyzed. Vertebrae of 85 patients, who received conservative treatment for acute OVFs, were included in the study and classified into two groups, union and delayed union, at 6 months after injury. To identify factors predicting delayed union, uni- and multivariate statistical analyses were performed. Vertebral MRI signal alternation patterns and endplate and IVD injuries were included as candidate factors in the logistic model.

Results

In association with OVFs, endplate injuries were observed in 103 of the 168 vertebrae (61%), and IVDs lesions were observed in 101 of 168 OVFs (60%); the occurrence of both injuries was significantly associated. Although no significant association with endplate and IVD injuries was identified, multivariate analysis demonstrated that intravertebral signal alternation (focal high signal intensity) and posterior wall injury were independent risk factors that predicted delayed union.

Conclusions

The results of this study showed that endplate and IVD injuries were found in approximately 60% of single and acute OVFs. These results suggest that fracture healing of OVFs would be mainly attributed to vertebral factors, including mechanical stress and metabolic status, among the three components of the anterior spinal column.

Primary cervical spine AL-κ amyloidoma: A case report and review of the literature

Of the myriad of variants of amyloidoses where abnormally folded proteins damage native tissue, primary cervical spine amyloidoma represents one of the rarest forms. Since clinical presentations and imaging findings appear similar to other pathologies, including abscesses, metastatic lesions, and inflammatory lesions, a definitive diagnosis requires a biopsy with specific immunohistochemical stains. We present the first known case of primary cervical amyloid light-chain (AL)-κ subtype amyloidoma and compare the clinical presentations, imaging findings, treatment options, and immunohistochemical subtypes of primary, hemodialysis, and multiple myeloma cervical amyloidomas. Our case is of a 58-year-old man who developed neck pain radiating to the left arm with bilateral upper extremity weakness over several months. Magnetic resonance imaging revealed a circumferential C1-C2 mass extending into the neural foramina inducing severe mass effect. The patient underwent C2 laminectomy and resection of the lesion which was discovered during surgery to be completely epidural. Postoperatively, his pain and weakness improved. A complete work-up was negative for systemic amyloidosis or inflammatory conditions. In the setting of a long clinical history of hemodialysis, this patient required specific staining and laboratory testing to correctly diagnose his primary cervical AL-κ subtype amyloidoma. Cervical amyloidomas comprise a very small minority of amyloid pathology with an exceptional prognosis following successful surgical resection and stabilization. It is recommended these patients undergo surgical resection with appropriate characterization and a complete work-up to rule out systemic disease.

Morphology of intervertebral disc ruptures evaluated by vacuum phenomenon using multi-detector computed tomography: association with lumbar disc degeneration and canal stenosis

Background

The progression of intervertebral disc (IVD) degeneration leads to rupture within IVD tissues. The location and appearance of areas of gaseous radiolucency in the IVD, known as vacuum phenomena (VPs), are considered to indirectly indicate the position and extent of IVD rupture. The clinical significance of VPs in degenerated IVDs is not fully understood. The purpose of this study is to assess and classify the morphology of IVD ruptures by the presence of intradiscal VPs, and to examine the association between morphological VP-positive IVD ruptures and degenerative lumbar diseases.

Methods

IVD rupture was evaluated by the presence of VPs using computed tomography (CT) imaging. VP shape (spot, linear, island) was classified using sagittal imaging, and VP distribution (A-N: anterior AF-NP; N: NP only; N-P: NP-posterior AF; A-N-P: anterior and posterior AF-NP) was classified using axial imaging. The disc height index (DHI) was calculated from lateral radiographs. Disc degeneration and lumbar spinal stenosis were evaluated by MRI grade.

Results

In the VP shape analysis, the island type was the most common, followed by linear and spot types. In the VP distribution analysis, A-N was the most common group, followed by N, N-P and A-N-P. Intra- and inter-observer reliabilities were statistically sufficient to classify different rupture shapes and distributions. The DHI tended to be lower in discs that contained VPs, especially in the anterior AF area. The shape and distribution of intradiscal VPs were significantly associated with the degree of disc degeneration and lumbar spinal stenosis graded by MRI. Discs with VPs extending from the NP into the anterior and/or posterior AF had a significantly higher proportion of advanced disc degeneration (Pfirrmann’s classification: grades IV and V).

Conclusions

This is the first study to analyze the morphology of IVD rupture evaluated by the presence of intradiscal VPs using CT imaging. This classification can comprehensively present the shape and axial distribution of VPs within IVDs. Intradiscal VPs are associated with the progression of disc degeneration and lumbar spinal stenosis.

Comparative study of the paraspinal muscles after OVF between the insufficient union and sufficient union using MRI

Background

Identification of poor prognostic factors for OVF is important but has not yet been clearly established. Despite paraspinal muscles could play an important role in the etiology of OVF, what influence time-dependent changes in paraspinal muscles have after OVF, and the impact on conservative treatments for patients who have an OVF remain largely unknown. The purposes of this study were to (1) evaluate time-dependent changes of the paraspinal musculature using MRI after injury in patients with osteoporotic vertebral fractures (OVFs), and (2) compare paraspinal muscles between conservatively treated patients with OVF who have successful union and those failed to conservative treatment.

Methods

A total of 115 consecutive patients who had sustained a recent OVF injury in the thoracolumbar region were assessed for eligibility using medical records and all required data were available from 90 patients who had been followed up for at least 6 months. Patients who needed to undergo surgery and patients who were diagnosed as having insufficient union after 6 months of follow-up were assigned to a group with insufficient union. Lumbar trunk parameters, relative cross-sectional area (rCSA) and proportion of fat infiltration (FI%) were calculated from MRI. To evaluate the time-dependent changes in the paraspinal muscle in patients after OVF injury, correlations between the timing of MRI and rCSA, FI% were determined. To clarify the impact of paraspinal muscles on the outcome of conservative treatments of patients with OVF, we compared rCSA between the groups.

Results

Sixty-five patients were assigned to a group with insufficient union and 25 patients were assigned to a group with successful union. FI% of the multifidus and erector spinae in the group with insufficient union were significantly greater than in the group with union. The timing of MRI in relation to initial injury was significantly correlated with FI% of the multifidus and erector spinae. rCSA of the erector spinae was significantly larger in the group with successful union than in the group with insufficient union.

Conclusions

These findings indicated a time-dependent increase of fatty degeneration of the multifidus and erector muscles, but no change in the rCSA and larger rCSAs of spinal erectors may play a role in successful union in patients with OVF.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2064-0) contains supplementary material, which is available to authorized users.

An unexpected cause of sacroiliitis in a patient with gout and chronic psoriasis with inflammatory arthritis: a case report

Background

Inflammatory back pain is a condition characterized by inflammation of the sacroiliac joints and lower spine. It is frequently seen in patients with spondyloarthropathies like ankylosing spondylitis, psoriatic arthritis, enteropathic arthritis and reactive arthritis. Inflammatory back pain can be caused by many other conditions like infection and crystal deposition such as gout. In this case, it is difficult to specifically identify gout as a cause by ordinary imaging like magnetic resonance imaging (MRI) or ultrasound.

Case presentation

This case report describes a young man with severe psoriasis, presumptive psoriatic spondyloarthropathy and chronic extensive tophaceous gout which was difficult to treat because of non-compliance with medications and lifestyle. He presented with inflammatory type low back and buttocks pain with raised inflammatory markers. MRI of the lower back and sacroiliac joints showed features of active sacroiliitis. He was subsequently treated with a Tumor Necrosis Factor (TNF) alpha inhibitor for presumed axial psoriatic arthritis and had no significant benefit. Two attempts DECT of the lumbar spine was not executed correctly. CT lumbar spine and SIJs showed L2/3 endplate and left SIJ erosions mostly related to gout. Rasburicase was introduced. The tophi decreased in size peripherally with marginal improvement in back pain. From this study, we want to bring to the attention of physicians that gout can lead to back pain with inflammatory changes on MRI. We also want to address the importance of other imaging modalities if the cause of the back pain is not clear.

Conclusion

This case is meant to highlight an important but overlooked cause of active sacroililitis and inflammatory type back pain in patients who have gout, and to bring to the attention that plain X-ray, MRI and ultrasound cannot differentiate between inflammatory sacroiliitis caused by seronegative arthritis versus gouty arthritis. CT scan can add more information but DECT is the preferred method for differentiation and identification of axial tophaceous gout.

Introduction to Neuroimaging

Primary care physicians are often tasked with evaluating neurologic symptoms, and imaging plays a critical role in neurologic diagnoses. Neuroradiology routinely employs advanced imaging modalities, and hence, determination of the appropriate imaging test and interpretation of findings in the clinical context can understandably be overwhelming. In this review article, we introduce resources that can guide physicians in the selection of neuroimaging tests and summarize guidelines on contrast agent administration. Key concepts on imaging techniques and terminology are reviewed, as is relevant for the primary care physician. We then present an overview of the typical imaging manifestations of brain pathologies, including stroke, traumatic injuries, infections, demyelinating and neurodegenerative processes, and neoplasms. Spine imaging is often considered for the evaluation of degenerative, infectious, or neoplastic etiologies, and the typical imaging findings in these scenarios are also summarized.

Lumbar spine epidural abscess and facet joint septic arthritis due to Streptococcus agalactiae: a case report

Background

Here we report a rare case of lumbar spine epidural abscess and facet joint septic arthritis caused by Streptococcus agalactiae, which had spread to the iliopsoas muscles, leading to urine retention.

Case presentation

A 68-year-old woman with low back pain experienced a sudden onset of bilateral lower limb weakness, it was followed 14 days later by urine retention. At consultation, magnetic resonance imaging and identification of serum β-hemolytic streptococci provided a diagnosis of Streptococcus agalactiae infection. She was started on antibiotics. Despite diminishing signs of inflammation, preoperative MRI showed an epidural mass at T12-L4 compressing the cord and involving the paravertebral muscles as well. Group B beta-hemolytic streptococci were detected in both urine and blood. Because of bilateral lower limb weakness and urine retention, T12-L4 hemilaminectomy was performed. The L3/L4 intertransverse ligament resected and abscess drained. Histopathology revealed that inflammatory cells had invaded the facet joint. Group B beta-hemolytic streptococci were identified, confirming the diagnosis. The patient continued with the antibiotics postoperatively, and her health rapidly improved.

Conclusion

Lumbar spine epidural abscess and facet joint septic arthritis caused by Streptococcus agalactiae is a clinical emergency, with significant morbidity and mortality especially with delayed diagnosis. A delay in both diagnosis and aggressive treatment can lead to not only severe neurological deficit but also to septicaemia, multiorgan failure, and even death.

Clinical and imaging characteristics in patients undergoing surgery for lumbar epidural lipomatosis

Background

Lumbar epidural lipomatosis (LEL) is characterized by abnormal accumulation of unencapsulated adipose tissue in the spinal epidural space. Such accumulation compresses the dural sac and nerve roots, and results in various neurological findings. However, the pathophysiology of LEL remains unclear. This study examined the associations between imaging and clinical findings in detail, and investigated the mechanisms underlying symptom onset by measuring intraoperative epidural pressures in LEL.

Methods

Sixteen patients (all men; mean age, 68.8 years) were enrolled between 2011 and 2015. Mean body mass index was 26.5 kg/m². Four cases were steroid-induced, and the remaining 12 cases were idiopathic. All patients presented with neurological deficits in the lower extremities. Cauda equina syndrome (CES) alone was seen in 8 patients, radiculopathy alone in 4, and both radiculopathy and CES (mixed CES) in 4. All patients subsequently underwent laminectomy with epidural lipomatosis resection and were followed-up for more than 1 year. We investigated the clinical course and imaging and measured epidural pressures during surgery.

Results

Subjective symptoms improved within 1 week after surgery. Mean Japanese Orthopaedic Association (JOA) score was 15.2 ± 2.8 before surgery, improving to 25.4 ± 2.5 at 1 year after surgery. On magnetic resonance imaging, all lipomatosis lesions included the L4–5 level. On preoperative computed tomography, saucerization of the laminae was not observed in radiculopathy cases, whereas saucerization of the posterior vertebral body was observed in all radiculopathy or mixed CES cases. Intraoperative epidural pressures were significantly higher than preoperative subarachnoid pressures. The results suggest that high epidural pressure resulting from the proliferation of adipose tissue leads to saucerization of the lumbar spine and subsequent symptoms.

Conclusions

Clinical courses were satisfactory after laminectomy. In LEL, epidural pressure increases and symptoms develop through the abnormal proliferation of adipose tissue. Higher epidural pressures induce saucerization of the laminae and/or posterior vertebral body. Furthermore, the direction of proliferative adipose tissue (i.e., site of saucerization) might be related to the types of neurological symptoms.

Quantitative MRI in early intervertebral disc degeneration: T1rho correlates better than T2 and ADC with biomechanics, histology and matrix content

Introduction

Low-back pain (LBP) has been correlated to the presence of intervertebral disc (IVD) degeneration on T2-weighted (T2w) MRI. It remains challenging, however, to accurately stage degenerative disc disease (DDD) based on T2w MRI and measurements of IVD height, particularly for early DDD. Several quantitative MRI techniques have been introduced to detect changes in matrix composition signifying early DDD. In this study, we correlated quantitative T2, T1rho and Apparent Diffusion Coefficient (ADC) values to disc mechanical behavior and gold standard early DDD markers in a graded degenerated lumbar IVD caprine model, to assess their potential for early DDD detection.

Methods

Lumbar caprine IVDs were injected with either 0.25 U/ml or 0.5 U/ml Chondroïtinase ABC (Cabc) to trigger early DDD-like degeneration. Injection with phosphate-buffered saline (PBS) served as control. IVDs were cultured in a bioreactor for 20 days under axial physiological loading. High-resolution 9.4 T MR images were obtained prior to intervention and after culture. Quantitative MR results were correlated to recovery behavior, histological degeneration grading, and the content of glycosaminoglycans (GAGs) and water.

Results

Cabc-injected IVDs showed aberrancies in biomechanics and loss of GAGs without changes in water-content. All MR sequences detected changes in matrix composition, with T1rho showing largest changes pre-to-post in the nucleus, and significantly more than T2 and ADC. Histologically, degeneration due to Cabc injection was mild. T1rho nucleus values correlated strongest with altered biomechanics, histological degeneration score, and loss of GAGs.

Conclusions

T2- and T1rho quantitative MR-mapping detected early DDD changes. T1rho nucleus values correlated better than T2 and ADC with biomechanical, histological, and GAG changes. Clinical implementation of quantitative MRI, T1rho particularly, could aid in distinguishing DDD more reliably at an earlier stage in the degenerative process.