MR and CT Imaging to Optimize CT-Guided Biopsies in Suspected Spondylodiscitis

Contemporary Role of Positron Emission Tomography (PET) in Endocarditis: A Narrative Review

Endocarditis, a serious infectious disease, remains a diagnostic challenge in contemporary clinical practice. The advent of advanced imaging modalities has contributed significantly to the improved understanding and management of this complex disease. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging has shown remarkable potential in improving the diagnostic accuracy of endocarditis. In the update of the Modified Duke Criteria, in 2023, The International Society for Cardiovascular Infectious Diseases (ISCVID) Working Group recognized specific 18F-FDG PET/CT findings as a major diagnostic criterion, particularly in patient with prosthetic valve endocarditis. The ability of PET to visualize metabolic activity allows for the identification of infective foci and could differentiate between infective and non-infective processes. This review examines the clinical utility of PET in differentiating infective endocarditis from other cardiovascular pathologies, highlighting its sensitivity and specificity in detecting native and prosthetic valve infections, including patients with transcatheter aortic valve implantation (TAVI), cardiac implantable devices (CIEDs), and left ventricular assistance devices (LVAD). Also, practical aspects and indications are illustrated to optimize the quality of imaging and reduce potential false positive results. In conclusion, the current use of PET in endocarditis has become a valuable diagnostic tool; as technological advances continue, PET will play an increasingly important role in the multidisciplinary approach to the management of endocarditis.

Culture-negative versus culture-positive in pyogenic spondylitis and analysis of risk factors for relapse

OBJECTIVES

This study aims to compare and analyze the clinical features, diagnosis, treatment and prognosis of culture-negative and culture-positive primary pyogenic spondylitis.

METHODS

In a retrospective analysis, 202 cases of adult primary pyogenic spondylitis with complete clinical data in our hospital from January 2013 to January 2020 were divided into two groups according to bacterial culture results: culture negative (n = 126) and culture positive (n = 76). We compare the clinical characteristics, diagnosis, treatment and prognosis of patients with different culture results.

RESULTS

The culture positive rate was 37.62% (76/202). There were no significant differences in age, gender, affected segment, spinal abscess, diabetes mellitus, course of disease, surgery, recurrence, and follow-up time between the two groups (p>.05). There were statistically significant differences in hospital admission erythrocyte sedimentation rate (ESR), admission C-reactive protein (CRP), admission white blood cell (WBC) count, discharge ESR, discharge CRP, ESR decline rate, CRP (p<.05). There were statistically significant differences in the rate of decline, hospitalization days, and body temperature ≥38 °C (p<.05). Higher CRP levels on admission, antibiotic treatment time <6 weeks, and body temperature ≥ 38 °C are independent risk factors for infection recurrence.

CONCLUSIONS

The culture-negative group's admission WBC, admission ESR, admission CRP, discharge ESR, discharge CRP, ESR decline rate, CRP decline rate, and hospital stay were lower than the culture positive group, the difference was statistically significant (p<.05). The independent risk factors for infection recurrence are higher CRP levels in hospital admission, antibiotic treatment time <6 weeks, and body temperature ≥ 38 °C.

The IFSD Score-A Practical Prognostic Model for Invasive Fungal Spondylodiscitis

Objectives: Invasive fungal spondylodiscitis (IFSD) is rare and could be lethal in certain circumstances. The previous literature revealed limited data concerning its outcomes. This study aimed to establish a risk-scoring system to predict the one-year mortality rate of this disease. Methods: A total of 53 patients from a multi-centered database in Taiwan were included in this study. All the clinicopathological and laboratory data were retrospectively analyzed. Variables strongly related to one-year mortality were identified using a multivariate Cox proportional hazards model. A receiver operating characteristic (ROC) curve was used to express the performance of our IFSD scoring model. Results: Five strong predictors were included in the IFSD score: predisposing immunocompromised state, the initial presentation of either radiculopathy or myelopathy, initial laboratory findings of WBC > 12.0 or <0.4 103/µL, hemoglobin < 8 g/dL, and evidence of candidemia. One-year mortality rates for patients with IFSD scores of 0, 1, 2, 3, and 4 were 0%, 16.7%, 56.3%, 72.7%, and 100%, respectively. The area under the curve of the ROC curve was 0.823. Conclusions: We developed a practical scoring model with easily obtained demographic, clinical, and laboratory parameters to predict the probability of one-year mortality in patients with IFSD. However, more large-scale and international validations would be necessary before this scoring model is commonly used.

[Spondylodiscitis]

Spondylodiscitis is a severe infectious disease of the spine that affects the intervertebral discs and adjacent vertebrae. It can lead to nonspecific pain, limited mobility, and destruction of spinal structures. Various pathogens, such as bacteria, fungi, or parasites, can trigger the disease. An early diagnosis and targeted treatment are crucial to reduce the risk of serious complications. Magnetic resonance imaging (MRI) with contrast agent and blood tests are essential for the diagnosis and assessing the course of the disease. The treatment includes conservative and surgical approaches. Conservative treatment consists of a minimum 6‑week antibiotic course and immobilization of the affected area. Surgical interventions, along with several weeks of antibiotic therapy, are indicated for instabilities or complications in order to eliminate the infection focus and to restore spinal stability.

2022 SPILF - Clinical Practice guidelines for the diagnosis and treatment of disco-vertebral infection in adults

These guidelines are an update of those made in 2007 at the request of the French Society of Infectious Diseases (SPILF, Société de Pathologie Infectieuse de Langue Française). They are intended for use by all healthcare professionals caring for patients with disco-vertebral infection (DVI) on spine, whether native or instrumented. They include evidence and opinion-based recommendations for the diagnosis and management of patients with DVI. ESR, PCT and scintigraphy, antibiotic therapy without microorganism identification (except for emergency situations), therapy longer than 6 weeks if the DVI is not complicated, contraindication for spinal osteosynthesis in a septic context, and prolonged dorsal decubitus are no longer to be done in DVI management. MRI study must include exploration of the entire spine with at least 2 orthogonal planes for the affected level(s). Several disco-vertebral samples must be performed if blood cultures are negative. Short, adapted treatment and directly oral antibiotherapy or early switch from intravenous to oral antibiotherapy are recommended. Consultation of a spine specialist should be requested to evaluate spinal stability. Early lifting of patients is recommended.

Image-Guided Biopsy in Acute Diskitis-Osteomyelitis: A Systematic Review and Meta-Analysis

BACKGROUND. The reported sensitivity and yield of image-guided biopsies for diskitis-osteomyelitis vary widely. OBJECTIVE. The purpose of this study was to perform a systematic review of the literature and meta-analysis of pooled sensitivity data to elucidate strategies for optimal image-guided biopsies among patients suspected to have diskitis-osteomyelitis. EVIDENCE ACQUISITION. A comprehensive literature search was performed for studies of patient populations with proven or suspected diskitis-osteomyelitis that included percutaneous image-guided biopsy as part of the workup algorithm. Type of pathogens, imaging modality used for biopsy guidance, tissue targeted, antibiotic administration at the time of biopsy, true microbiology positives, true microbiology negatives, false microbiology positives, false microbiology negatives, disease (i.e., diskitis-osteomyelitis) positives as determined by reference standard, true infection positives (i.e., positive microbiology or pathology results), and total number of biopsies performed were extracted from the studies. Microbiology sensitivity, microbiology biopsy yield, and infection sensitivity were calculated from the pooled data. These terms and the data required to calculate them were also defined in detail. EVIDENCE SYNTHESIS. Thirty-six articles satisfied inclusion criteria and were used for analysis. The pooled microbiology sensitivity, infection sensitivity, and microbiology biopsy yields were 46.6%, 70.0%, and 26.7%, respectively. Mycobacterium tuberculosis-only microbiology sensitivity was significantly higher than both pyogenic bacteria and mixed-organism microbiology sensitivity (p < .001). Staphylococcus aureus was the most common causative organism (28.6%). Pooled microbiology sensitivity was not significantly different for CT guidance and fluoroscopy guidance (p = .16). There was a statistically significant difference between pooled microbiology sensitivity of bone/end plate (45.5%) and disk/paravertebral soft-tissue (64.8%) image-guided biopsies (p < .001). There was no statistically significant difference in pooled microbiology sensitivities for patients who received antibiotics before the procedure (46.2%) and those who did not (44.6%) (p = .70). CONCLUSION. Image guidance by CT or fluoroscopy does not affect microbiology yield, disk and paravertebral soft-tissue biopsies should be considered over bone and end plate biopsies, and preprocedural antibiotic administration does not appear to impact biopsy results. CLINICAL IMPACT. Understanding and correctly applying reported statistics contribute to appropriate interpretation of the abundant literature on this topic and optimization of care for patients with diskitis-osteomyelitis.

Site matters: Image-guided percutaneous sampling of intervertebral disc results in increased positive diagnostic yield in spondylodiscitis

Spondylodiscitis is a common referral to spinal on call services. Identification of the causative organism is vital in order to dictate the appropriate antibiotic treatment. In this context, the surgical and interventional radiology team is often asked to perform a diagnostic biopsy. The aim of the present study was to assess whether the sampling location affects the diagnostic yield. Our results suggest that the overall positive diagnostic yield was 35%. When disc material was included in the sample the diagnostic yield significantly improved to 47%. Bone sampling alone had a positive yield of 15%. Age, pre-biopsy CRP, pre-biopsy use of antibiotics did not seem to affect the likelihood of obtaining a positive yield. These results suggests that when performing image guided biopsies for suspected cases of spondylodiscitis the inclusion of disc material is important.

The Incidence, Changes and Treatments of Cervical Deformity After Infection and Inflammation

A healthy cervical spine with normal movement is the basis of many daily activities and is essential for maintaining a good quality of life. However, the alignment, fusion, and structure of the cervical spine can change for various reasons, leading to cervical deformity, mainly kyphosis. Approximately 5%‒20% of spinal infections in the cervical spine cause cervical deformity. The deformity can recover early; however, the disease's long-term existence or the continuous action of abnormal stress may lead to intervertebral fusion and abnormal osteophytes. Many gaps and controversies exist regarding infectious cervical deformities, including a lack of clear definitions and an acceptable classification system thereby requiring further research. Moreover, there is no consensus on the indications for postinfectious cervical deformity associated with <i>Mycobacterium tuberculosis</i>, <i>Staphylococcus aureus</i>, and Brucellosis. Therefore, we reviewed and discussed the incidence, clinical manifestations, changes, and treatment of infectious and inflammatory secondary cervical deformities from common to rare to provide a theoretical basis for clinical decision-making.

Quality of Life Following Surgical and Conservative Therapy of Pyogenic Spinal Infection: A Study of Long-term Outcome in 210 Patients

OBJECT

 The management and recommendations for treatment strategies of pyogenic spinal infection are still a highly controversial issue. The purpose of this study was to evaluate patient's quality of life (QoL) after surgical and conservative treatment of spinal infection.

MATERIALS AND METHODS

 We conducted a retrospective, single-center study. All patients treated between 2009 and 2016 were included in this study. For evaluation of QoL, we recorded each patient's satisfaction according to the 36-Item Short Form Health Survey (SF-36) questionnaire. Scores were compared with a U.S. standard population.

RESULTS

 Two hundred and ten adult patients with spondylodiskitis were identified. Of these, 155 (74%) underwent surgery and 55 (26%) were treated conservatively. The mean overall age was 68.6 (23-98) years. Seventy-two patients were females and 138 patients were males. The mean outcome values in the surgical group did not reach the level of the normative sample in one of eight items, whereas the conservative group revealed a reduced QoL in all items. Intergroup comparison revealed significant differences in all items (p < 0.05).

CONCLUSION

 In the patient population we investigated, QoL in surgically treated patients was better than that in conservatively managed patients.

Postoperative Bildgebung der Wirbelsäule

Die Bildgebung der postoperativen Wirbelsäule hat im Wesentlichen zwei Aufgaben: Sie dient der Kontrolle des operativen Erfolgs und der Identifikation von Komplikationen. Dafür stehen die konventionelle Röntgenaufnahme, Computertomographie (CT), Myelographie und Magnetresonanztomographie (MRT) zur Verfügung. Unter Berücksichtigung der präoperativen Situation, der durchgeführten Operation und der postoperativen Beschwerdekonstellation ist es Aufgabe der Radiologinnen und Radiologen, die passende Modalität für eine suffiziente Diagnostik zu wählen. Insbesondere der Zustand nach Implantation von Fremdmaterial bedeutet eine technische Herausforderung im Rahmen der Bildakquisition. In der Befundung sehen sich die Radiologinnen und Radiologen mit der Aufgabe konfrontiert, zwischen natürlichen, zu erwartenden postoperativen Veränderungen und relevanten Komplikationen zu differenzieren. Ein reger Austausch mit Patientinnen und Patienten und zuweisenden Klinikerinnen und Klinikern ist dabei unerlässlich. Insbesondere klinische Hinweise auf einen Infekt, neue oder deutliche progrediente neurologische Ausfallserscheinungen und das Konus-Kauda-Syndrom erfordern eine zeitnahe Diagnosestellung, um eine rasche Therapieeinleitung zu gewährleisten.

Culture Yield in the Diagnosis of Native Vertebral Osteomyelitis: A Single Tertiary Center Retrospective Case Series with Literature Review

Background

Vertebral osteomyelitis is a serious condition that requires prompt diagnosis to avoid delays in proper management. There is no well-defined gold standard for diagnosis. We describe the current diagnostic approach at our institution, with a focus on the yield of image-guided vertebral biopsy.

Methods

We performed a single-centre 10-year retrospective case series, including adults with imaging suggestive of vertebral osteomyelitis/discitis, with either positive blood cultures, and/or a vertebral biopsy. We defined positive histopathology as our gold standard for test characteristic evaluation of biopsy cultures.

Results

Out of 694 patients identified, 221 met our inclusion criteria, and 173/221 (78.2%) patients underwent a spinal biopsy. Of those patients with biopsies, 113 (65%) had received antibiotics within 2 weeks preceding their evaluation. Six of 43 (13.9%) bone specimens were positive by culture, while 66/152 (43.4%) of disc specimens were culture positive. Forty-seven of 84 (55.9%) histopathology (bone or disc) specimens were diagnostic for osteomyelitis/discitis. The sensitivity of bone and disk culture were 30.0% and 56.0%, respectively, with specificities of 92.8% and 75.0%, respectively. Twenty-three (13.4%) patients had repeat biopsies, including 10 bone specimens and 14 disc specimens, and 11 (47.8%) specimens had histopathology performed which diagnosed an additional 3/23 patients (13% additional diagnostic yield).

Conclusions

Culture of percutaneous biopsy of disc resulted in the highest diagnostic yield. Histopathology added to the diagnostic yield in culture-negative specimens. Histopathologic evaluation of bone had better yield than bone culture. A repeat biopsy can add to the diagnostic yield.

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.

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.

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.

Review article: the current status of CT-guided needle biopsy of the spine

CT-guided percutaneous needle biopsy of the spine is a well-described technique for determining the nature of indeterminate vertebral lesions or establishing a diagnosis of spinal infection, the high diagnostic accuracy and the safety of the procedure having been extensively documented. The purpose of the current article is to review the literature to date on CT-guided spinal biopsy. Specifically, indications for spinal biopsy, techniques for optimising yield, detail of the approaches for various spinal levels which is dependent upon both the region within the spinal column and lesion location within the vertebra (body vs. neural arch), determinants of biopsy outcome and complications are covered. It is hoped that the review will be of particular benefit to junior radiologists who are required to perform this procedure.

Studies on 11 Cases of Spinal Epidural Abscess and Literature Review

Objective

In the present study, we aimed to describe the clinical features, diagnosis, treatment, and prognosis of spinal epidural abscess (SEA).

Methods

The complete clinical data of 11 SEA patients who were treated in our hospital system from January 2015 to June 2018 were retrospectively analyzed. Moreover, the clinical features, diagnosis, treatment, and prognosis of 642 SEA cases collected from the foreign literature from 2010 to 2019 were also investigated.

Results

Among our 11 SEA patients, nine cases had purulent inflammation, two cases had tuberculosis, two cases had infection caused by Staphylococcus aureus, one case had infection caused by Streptococcus constellatus, one case had infection caused by Klebsiella pneumoniae, five cases showed negative bacterial culture, and two cases had Mycobacterium tuberculosis. All 11 cases showed focal spinal pain, eight cases exhibited neurological deficits, and six cases experienced fever. Nine of the 11 cases involved the lumbosacral spine, one case involved the thoracic spine, and one case involved the cervical spine. Eight patients had a longer course of disease (>2 weeks), all 11 patients had vertebral osteomyelitis, and nine patients had intervertebral discitis. One patient had motor dysfunction of arms and legs, one patient had lower limb motor dysfunction, one patient had limb numbness, one patient experienced relapse after the conservative treatment, and one patient experienced relapse after the surgical treatment. The follow-up time was 15–24 months.

Conclusion

The classic diagnosis of triads (focal spine pain, neurological deficit, and fever) was less specific for SEA. MRI examination, blood culture, tissue culture, and biopsy could be used for the diagnosis for SEA. Suppuritis was a common cause of SEA. Early detection, early diagnosis and early treatment, as well as the selection of the most suitable treatment regimen based on comprehensive evaluation, played crucial roles in a better prognosis of SEA. There was no statistically significant difference in terms of the general condition, diagnosis, treatment and prognosis between the patients with negative and positive culture results (P>0.05). For SEA patient with negative culture, antibiotic treatment should be used empirically.

Early versus Delayed Surgery for Spinal Epidural Abscess : Clinical Outcome and Health-Related Quality of Life

Objective

Spinal epidural abscess (SEA) is a severe and life-threatening disease. Although commonly performed, the effect of timing in surgical treatment on patient outcome is still unclear. With this study, we aim to provide evidence for early surgical treatment in patients with SEA.

Methods

Patients treated for SEA in the authors’ department between 2007 and 2016 were included for analysis and retrospectively analyzed for basic clinical parameters and outcome. Pre- and postoperative neurological status were assessed using the American Spinal Injury Association Impairment Scale (AIS). The self-reported quality of life (QOL) based on the Short-Form Health Survey 36 (SF-36) was assessed prospectively. Surgery was defined as “early”, when performed within 12 hours after admission and “late” when performed thereafter. Conservative therapy was preferred and recommend in patients without neurological deficits and in patients denying surgical intervention.

Results

One hundred and twenty-three patients were included in this study. Forty-nine patients (39.8%) underwent early, 47 patients (38.2%) delayed surgery and 27 (21.9%) conservative therapy. No significant differences were observed regarding mean age, sex, diabetes, prior history of spinal infection, and bony destruction. Patients undergoing early surgery revealed a significant better clinical outcome before discharge than patients undergoing late surgery (p=0.001) and conservative therapy. QOL based on SF-36 were significantly better in the early surgery cohort in two of four physical items (physical functioning and bodily pain) and in one of four psychological items (role limitation) after a mean follow-up period of 58 months. Readmission to the hospital and failure of conservative therapy were observed more often in patients undergoing conservative therapy.

Conclusion

Our data on both clinical outcome and QOL provide evidence for early surgery within 12 hours after admission in patients with SEA.

[Pyogenic spondylodiscitis: symptoms, diagnostics and therapeutic strategies]

BACKGROUND

Pyogenic spondylodiscitis is a rare disease that is being diagnosed with increasing frequency in recent years. It is associated with a high morbidity and mortality.

DIAGNOSIS

Often, because of its nonspecific symptoms, pyogenic spondylodiscitis is diagnose with some delay. In addition to pathogen detection, MRI is the gold standard to diagnose pyogenic spondylodiscitis. Also, x-ray imaging and CT can be carried out for surgical planning and for subsequent follow-up imaging. If blood or tissue cultures are negative, open surgical biopsies should be preferred over CT-guided biopsies.

THERAPY

The therapy can be conservative, such as immobilization, as well as antibiotics and analgesics, or surgical. If, for example, neurological deficits, spinale instabilities or deformities, septic disease progression or extensive abscess formations are present, surgical therapy is indicated. The surgical treatment strategies depend on the severity of the disease.

OUTLOOK

The prognosis is dependent on a rapid diagnosis and a swift start to therapy. There is no clear evidence with regard to treatment options (conservative vs. surgical therapy).

Combination of Imaging Features and Clinical Biomarkers Predicts Positive Pathology and Microbiology Findings Suggestive of Spondylodiscitis in Patients Undergoing Image-Guided Percutaneous Biopsy

BACKGROUND AND PURPOSE

Pathology and microbiology results for suspected spondylodiscitis on MR imaging are often negative in up to 70% of cases. We aimed to predict whether MR imaging features will add diagnostic value when combined with clinical biomarkers to predict positive findings of spondylodiscitis on pathology and/or microbiology from percutaneous biopsy.

MATERIALS AND METHODS

In this retrospective single-center institutional review board-approved study, patients with radiologically suspected spondylodiscitis and having undergone percutaneous biopsies were assessed. Demographic characteristics, laboratory values, and tissue and blood cultures were collected. Pathology and microbiology results were used as end points. Three independent observers provided MR imaging-based scoring for typical MR imaging features for spondylodiscitis. Multivariate logistic regression and receiver operating characteristic analysis were performed to determine an optimal combination of imaging and clinical biomarkers in predicting positive findings on pathology and/or microbiology from percutaneous biopsy suggestive of spondylodiscitis.

RESULTS

Our patient cohort consisted of 72 patients, of whom 33.3% (24/72) had spondylodiscitis. The mean age was 63 ± 16 years with a male/female ratio of 41:31. Logistic regression revealed a combination with an area under the curve of 0.72 for pathology and 0.68 for pathology and/or microbiology. Epidural enhancement on MR imaging improved predictive performance to 0.87 for pathology and 0.78 for pathology and/or microbiology.

CONCLUSIONS

Our findings demonstrate that epidural enhancement on MR imaging added diagnostic value when combined with clinical biomarkers to help predict which patients undergoing percutaneous biopsy will have positive findings for spondylodiscitis on pathology and/or microbiology.

CORRELATION BETWEEN FINDINGS IN MAGNETIC RESONANCE AND BIOPSY IN THE DIAGNOSIS OF SPONDYLODISCITIS

ABSTRACT Objective To correlate magnetic resonance imaging (MRI) findings with the microbiological and anatomopathological diagnosis of spinal infection. Methods A retrospective, cohort review of online medical records (laboratory, anatomopathology and diagnostic imaging sector) of patients diagnosed with spondylodiscitis, who underwent a full spine MR scan between January 2014 and July 2018 at the Department of Orthopedics and Traumatology of the Universidade Federal de São Paulo. Results Staphylococcus aureus was the most commonly found etiological agent (57%). Blood culture was positive in 76% of cases and 82% of the patients who underwent biopsy had a spondylodiscitis diagnosis. Pain was the most prevalent clinical symptom and the lumbosacral spine was the most frequent site of infection. T1 hyposignal, T2/STIR hypersignal, and terminal plate destruction were verified in almost all MR scans. Conclusions No direct correlation was found between MR findings and any specific etiological agent. Blood culture and biopsy are important diagnostic tools that should be used for accurate diagnosis of the infectious agent . Level of evidence IV; Diagnostic Study.

Spinal Infections: An Update

Spinal infection poses a demanding diagnostic and treatment problem for which a multidisciplinary approach with spine surgeons, radiologists, and infectious disease specialists is required. Infections are usually caused by bacterial microorganisms, although fungal infections can also occur. The most common route for spinal infection is through hematogenous spread of the microorganism from a distant infected area. Most patients with spinal infections diagnosed in early stages can be successfully managed conservatively with antibiotics, bed rest, and spinal braces. In cases of gross or pending instability, progressive neurological deficits, failure of conservative treatment, spinal abscess formation, severe symptoms indicating sepsis, and failure of previous conservative treatment, surgical treatment is required. In either case, close monitoring of the patients with spinal infection with serial neurological examinations and imaging studies is necessary.

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.

Diagnostic Performance of CT-Guided Bone Biopsies in Patients with Suspected Osteomyelitis of the Appendicular and Axial Skeleton with a Focus on Clinical and Technical Factors Associated with Positive Microbiology Culture Results

PURPOSE

To assess diagnostic performance of CT-guided percutaneous needle bone biopsy (CTNBB) in patients with suspected osteomyelitis and analyze whether certain clinical or technical factors were associated with positive microbiology results.

MATERIALS AND METHODS

All CTNBBs performed in a single center for suspected osteomyelitis of the appendicular and axial skeleton during 2003-2018 were retrospectively reviewed. Specific inclusion criteria were clinical and radiologic suspicion of osteomyelitis. Standard of reference was defined using outcome of surgical histopathology and microbiology culture and clinical and imaging follow-up. Technical and clinical data (needle size, comorbidities, clinical factors, laboratory values, blood cultures) were collected. Logistic regression was performed to assess associations between technical and clinical data and microbiology biopsy outcome.

RESULTS

A total of 142 CTNBBs were included (46.5% female patients; age ± SD 46.10 y ± 22.8), 72 (50.7%) from the appendicular skeleton and 70 (49.3%) from the axial skeleton. CTNBB showed a sensitivity of 42.5% (95% confidence interval [CI], 32.0%-53.6%) in isolating the causative pathogen. A higher rate of positive microbiology results was found in patients with intravenous drug use (odds ratio [OR] = 5.15; 95% CI, 1.2-21.0; P = .022) and elevated white blood cell count ≥ 10 × 10⁹/L (OR = 3.9; 95% CI, 1.62-9.53; P = .002). Fever (≥ 38°C) was another clinical factor associated with positive microbiology results (OR = 3.6; 95% CI, 1.3-9.6; P = .011).

CONCLUSIONS

CTNBB had a low sensitivity of 42.5% for isolating the causative pathogen. Rate of positive microbiology samples was significantly higher in patients with IV drug use, elevated white blood cell count, and fever.

Impact of MRI, CT, and Clinical Characteristics on Microbial Pathogen Detection Using CT-Guided Biopsy for Suspected Spondylodiscitis

Spondylodiscitis accounts for 2–7% of osteomyelitis cases and is characterized by pain, systemic inflammation, and permanent neurological deficits. We aimed to identify imaging characteristics and clinical parameters to successfully predict microbiological pathogens by computed tomography (CT)-guided biopsy in suspected spondylodiscitis cases. Forty consecutive patients (mean age 65.1 years) with suspected spondylodiscitis underwent CT-guided biopsy. CT features (non-sclerotic endplate erosions (NSEs)), magnetic resonance criteria (paravertebral/epidural abscess (PA/EA) formation), and clinical data (C-reactive protein (CRP) > 50 mg/L) were assessed for their predictive potential. NSEs were detected in 6/11 (54.5%) and 1/29(3.4%) patients with positive and negative microbiology, respectively. PA and EA, respectively, were present in 7/11(63.6%) and 3/11 patients with positive microbiology and 7/29 (24.1%) and 2/29 patients with negative microbiology. CRP > 50 was observed in 7/11 (63.6%) and in 7/29 (24.1%) patients with positive and negative microbiology, respectively. Three double combinations possessed near-perfect specificity (PA + NSE, 100%; PA + CRP > 50, 96.6%; NSE + CRP > 50, 96.6%). The top three Youden indices included combinations with NSE. Since CT/magnetic resonance (MR) imaging and CRP are routinely used to evaluate spondylodiscitis, the presented diagnostic criteria and combinations can aid decision-making for biopsy.

Computed-tomography-guided biopsy in suspected spondylodiscitis: Single-center experience including 201 biopsy procedures

Our propose is to evaluate CT-guided biopsies in suspected spondylodiscitis with respect to puncture site, microbiology findings, histopathology findings and impact on antibiotic therapy. 86 CT-guided spine interventions in suspected spondylodiscitis comprising 201 biopsy procedures were analyzed. Medical records of all patients were screened for microbiology and histopathology reports as well as date, duration and kind of antibiotic therapy. Statistical analyses included calculation of Chi2-tests and logistic regression analyses. Locations of biopsies were intervertebral disc (48.3%), paravertebral soft-tissue (38.3%) and vertebral body (10.9%). Positive microbiological findings were found altogether in 33.8% of cases, positive histopathological findings in 53.6%. Significant associations between positive microbiological findings, positive histopathological findings and antibiotic therapy, respectively, were found. Location of biopsies did not significantly influence rate of positive findings. From the variables age, white blood cell count, serum creatinine and puncture site, none were found to be an independent predictor for a positive microbiological result. We concluded that CT-guided biopsy of intervertebral disc and paravertebral soft tissue yields positive microbiologic findings in a significant proportion of cases. Puncture site is not associated with positive results of microbiology or histopathology.

The Efficacy of Computed Tomography-Guided Percutaneous Spine Biopsies in Determining a Causative Organism in Cases of Suspected Infection: A Systematic Review

Purpose

In suspected spondylodiscitis and vertebral osteomyelitis, computed tomography (CT)-guided biopsies are often performed to determine a causative organism and guide antimicrobial therapy. The aim of this study is to determine the diagnostic culture yield of CT-guided biopsies performed in cases of suspected spinal infections.

Methods

A literature search of PubMed and MEDLINE up to April 2017 was performed for keywords “CT guided vertebral biopsy infection,” “CT-guided spine biopsy infection,” “CT guided spine biopsy yield,” and “CT guided vertebral biopsy yield.” Inclusion criteria primarily consisted of studies exclusively using CT-guided biopsies in cases of suspected infectious lesions only. After study selection, published articles were analysed to determine diagnostic culture yield. Descriptive statistics were applied.

Results

220 search results were screened; 11 met our inclusion criteria and were reviewed. In total, 647 biopsies of suspected infectious spinal lesions were performed. Positive cultures were obtained in 241 cases. Upon excluding one paper's skewed results, the net pooled results culture yield was 33%. Several cultures grew multiple organisms, leading to a total of 244 species identified. Most common isolated organisms include S taphylococcus aureus (n = 83), coagulase-negative S taphylococcus (n = 45), and Mycobacteria (n = 38).

Conclusions

The diagnostic culture yield of CT-guided biopsies in cases of suspected spinal infection is 33%. In the majority of cases, a causative organism is not identified. This suggests that improvements can be made in biopsy technique and specimen transfer to optimize culture yield and increase the clinical value of the procedure.

Endoscopic Decompression Can Be Effective for Diagnosing and Treating Tubercular Spondylodiskitis with Early Epidural Spinal Compression: A Retrospective Study of 18 Cases

Study Design

Retrospective study.

Purpose

In this study, we describe an endoscopic method of effectively treating tubercular lumbar spondylodiskitis with early onset epidural spinal cord compression in the lumbar spine on magnetic resonance imaging (MRI).

Overview of Literature

Percutaneous aspiration and biopsy of spondylodiskitis under ultrasonography and computer tomography scan invariably provides an inadequate diagnosis.

Methods

From May 2015 to May 2017, 18 patients presented with intractable back pain and were diagnosed with tubercular spondylodiskitis on MRI; these patients were enrolled in this study. The goal was to confirm the pathogen on biopsy, drain the abscess, and perform debridement. Chemotherapy was started after histologic diagnosis, and data collected included blood cell counts, erythrocyte sedimentation rate, C-reactive protein, and repeat MRI after 3 months.

Results

Mean duration of surgery was 52 minutes. Mean follow-up was 17 months. The average preoperative Visual Analog Scale score of 8 (range, 6–10) decreased to 3 (range, 1–8) postoperatively. Tubercular spondylodiskitis was observed in 14 cases; two cases were pyogenic, and the biopsy was inconclusive in two cases. After adequate chemotherapy, no recurrences were noted.

Conclusions

We hereby conclude that endoscopic biopsy and drainage can provide a better diagnosis and decrease pain in a predictable manner.

Spondylodiscitis: Diagnosis and Treatment Options

BACKGROUND

A recent population-based study from Denmark showed that the incidence of spondylodiscitis rose from 2.2 to 5.8 per 100 000 persons per year over the period 1995-2008; the age-standardized incidence in Germany has been estimated at 30 per 250 000 per year on the basis of data from the Federal Statistical Office (2015). The early diagnosis and treatment of this condition are essential to give the patient the best chance of a good outcome, but these are often delayed because it tends to present with nonspecific manifestations, and fever is often absent.

METHODS

This article is based on a systematic search of Medline and the Cochrane Library for the period January 2009 to March 2017. Of the 788 articles identified, 30 publications were considered.

RESULTS

The goals of treatment for spondylodiscitis are to eliminate infection, restore functionality of the spine, and relieve pain. Magnetic resonance imaging (MRI) remains the gold standard for the radiological demonstration of this condition, with 92% sensitivity and 96% specificity. It also enables visualization of the spatial extent of the infection and of abscess formation (if present). The most common bacterial cause of spondylodiscitis in Europe is Staphylococcus aureus, but tuberculous spondylodiscitis is the most common type worldwide. Antibiotic therapy is a pillar of treatment for spondylodiscitis and should be a part of the treatment in all cases. Neurologic deficits, sepsis, an intraspinal empyema, the failure of conservative treatment, and spinal instability are all indications for surgical treatment.

CONCLUSION

The quality of life of patients who have been appropriately treated for spondylodiscitis has been found to be highly satisfactory in general, although back pain often persists. The risk of recurrence increases in the presence of accompanying illnesses such as diabetes mellitus, renal failure, or undrained epidural abscesses.