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

Influence factors of metagenomic next-generation sequencing negative results in diagnosed patients with spinal infection

The aim of this study was to evaluate the influence factors of metagenomic next-generation sequencing (mNGS) negative results in the diagnosed patients with spinal infection. mNGS test was applied in a cohort of 114 patients with suspected spinal infection, among which 56 patients had a final diagnosis of spinal infection. mNGS achieved a sensitivity of 75.0% (95% CI, 61.6% to 85.6%) and a specificity of 84.5% (95% CI, 72.6% to 92.7%), using histopathology and culture results as reference. Diagnosed patients with a negative culture result had lower white blood cell account, percentage of neutrophilic granulocyte, C-reactive protein (all P<0.05) and relatively higher rate of prior antimicrobial treatment history (P=0.059). However, diagnosed patients with a negative mNGS result did not have such difference with mNGS-positive patients, suggesting that mNGS was not strictly limited by the above indicators, which presented the advantages of this technique from another point of view.

Factors affecting the success of CT-guided core biopsy of musculoskeletal lesions with a 13-G needle

OBJECTIVE

To determine the value of CT-guided bone core biopsy and investigate factors that affect diagnostic yield and biopsy outcome.

MATERIALS AND METHODS

The single-centre retrospective analysis included 447 patients who had CT-guided core biopsy with a 13-G needle (Bonopty®) from January 2016 to December 2021. Histological results or ≥ 6 months of clinical and radiological follow-up served as outcome references. A successful biopsy was classified as "diagnostic" when a definitive diagnosis was made and "adequate" when only the malignant or benign nature of the tumour could be determined. Biopsies were "nondiagnostic" when the nature of the lesion could not be determined. The occult lesions were defined as not seen on CT but visible on other modalities.

RESULTS

In 275 (62%) females and 172 (38%) males, the overall success rate was 85% (383 biopsies), with 314 (70%) diagnostic biopsies and 69 (15%) adequate biopsies. There was no relationship between biopsy success and the localisation of the lesion, length of biopsy material, or number of biopsy attempts. The lesions' nature had a statistically significant effect on biopsy success with lytic and mixed lesions having the highest success rate. Occult lesions had the lowest success rate.

CONCLUSION

CT-guided bone core biopsy is an effective method in the workup of musculoskeletal diseases with the highest success rate in lytic and mixed lesions. No apparent relationship was found between biopsy success and biopsy length, number of attempts, or localisation of the lesion.

Transpedicular Contrast-enhanced CT-guided biopsy of the body and dens of the axis avoiding the trans-oral approach: Technical report and literature review

This technical report illustrates the technique to perform computed tomography (CT)-guided bone biopsies in the body and dens of the axis (C2 vertebra) through a posterior transpedicular approach with the use of preoperative contrast-enhanced scans to highlight the course of the vertebral artery. The technique is presented through two exemplification cases: a pediatric patient with osteoblastoma and secondary aneurysmal bone cyst and one adult patient with melanoma metastasis. This case highlights the potential of the CT-guided posterolateral/transpedicular approach for performing safe and effective biopsies in the body and dens of C2, even in pediatric patients.

Diagnostic Approach and Differences between Spinal Infections and Tumors

STUDY DESIGN

A systematic review of the literature about differential diagnosis between spine infection and bone tumors of the spine.

BACKGROUND AND PURPOSE

The differential diagnosis between spine infection and bone tumors of the spine can be misled by the prevalence of one of the conditions over the other in different areas of the world. A review of the existing literature on suggestive or even pathognomonic imaging aspects of both can be very useful for correctly orientating the diagnosis and deciding the most appropriate area for biopsy. The purpose of our study is to identify which imaging technique is the most reliable to suggest the diagnosis between spine infection and spine bone tumor.

METHODS

A primary search on Medline through PubMed distribution was made. We identified five main groups: tuberculous, atypical spinal tuberculosis, pyogenic spondylitis, and neoplastic (primitive and metastatic). For each group, we evaluated the commonest localization, characteristics at CT, CT perfusion, MRI, MRI with Gadolinium, MRI diffusion (DWI) and, in the end, the main features for each group.

RESULTS

A total of 602 studies were identified through the database search and a screening by titles and abstracts was performed. After applying inclusion and exclusion criteria, 34 articles were excluded and a total of 22 full-text articles were assessed for eligibility. For each article, the role of CT-scan, CT-perfusion, MRI, MRI with Gadolinium and MRI diffusion (DWI) in distinguishing the most reliable features to suggest the diagnosis of spine infection versus bone tumor/metastasis was collected.

CONCLUSION

Definitive differential diagnosis between infection and tumor requires biopsy and culture. The sensitivity and specificity of percutaneous biopsy are 72% and 94%, respectively. Imaging studies can be added to address the diagnosis, but a multidisciplinary discussion with radiologists and nuclear medicine specialists is mandatory.

Percutaneous CT-Guided Bone Biopsies: Indications, Feasibility and Diagnostic Yield in the Different Skeletal Sites-From the Skull to the Toe

CT-guided bone biopsies are currently the diagnostic tool of choice for histopathological (and microbiological) diagnoses of skeletal lesions. Several research works have well-demonstrated their safety and feasibility in almost all skeletal regions. This comprehensive review article aims at summarizing the general concepts in regard to bone biopsy procedures, current clinical indications, the feasibility and the diagnostic yield in different skeletal sites, particularly in the most delicate and difficult-to-reach ones. The choice of the correct imaging guidance and factors affecting the diagnostic rate, as well as possible complications, will also be discussed. Since the diagnostic yield, technical difficulties, and complications risk of a CT-guided bone biopsy significantly vary depending on the different skeletal sites, subdivided analyses of different anatomical sites are provided. The information included in the current review article may be useful for clinicians assisting patients with possible bone neoplasms, as well as radiologists involved in the imaging diagnoses of skeletal lesions and/or in performing bone biopsies.

Ultrasound-Guided Percutaneous Bone Biopsy: Feasibility, Diagnostic Yield and Technical Notes

While nowadays, CT-guided bone biopsy represents the gold standard tool for histopathological and microbiological diagnosis of skeletal lesions, the role of US-guided bone biopsy has not yet been fully explored. US-guided biopsy offers several advantages, such as the absence of ionizing radiation, fast acquisition time, as well as good intra-lesional echo, and structural and vascular characterization. Despite that, a consensus in regard to its applications in bone neoplasms has not been established. Indeed CT-guided technique (or fluoroscopic ones) still represents the standard choice in clinical practice. This review article aims to review the literature data about US-guided bone biopsy, underlying clinical-radiological indications, advantages of the procedure and future perspectives. Bone lesions taking the best advantages of the US-guided biopsy are osteolytic, determining the erosion of the overlying bone cortex and/or with an extraosseous soft-tissue component. Indeed, osteolytic lesions with extra-skeletal soft-tissue involvement represent a clear indication for US-guided biopsy. Moreover, even lytic bone lesions with cortical thinning and/or cortical disruption, especially located in the extremities or pelvis, can be safely sampled with US guidance with very good diagnostic yield. US-guided bone biopsy is proven to be fast, effective and safe. Additionally, it offers real-time needle evaluation, an advantage when compared to CT-guided bone biopsy. In the current clinical settings, it seems relevant to select the exact eligibility criteria for this imaging guidance since the effectiveness can vary depending on the type of lesion and body site involved.

Impact of radiation dose reduction and iterative image reconstruction on CT-guided spine biopsies

This study aimed to systematically evaluate the impact of dose reduction on image quality and confidence for intervention planning and guidance regarding computed tomography (CT)-based intervertebral disc and vertebral body biopsies. We retrospectively analyzed 96 patients who underwent multi-detector CT (MDCT) acquired for the purpose of biopsies, which were either derived from scanning with standard dose (SD) or low dose (LD; using tube current reduction). The SD cases were matched to LD cases considering sex, age, level of biopsy, presence of spinal instrumentation, and body diameter. All images for planning (reconstruction: "IMR1") and periprocedural guidance (reconstruction: "iDose4") were evaluated by two readers (R1 and R2) using Likert scales. Image noise was measured using attenuation values of paraspinal muscle tissue. The dose length product (DLP) was statistically significantly lower for LD scans regarding the planning scans (SD: 13.8 ± 8.2 mGy*cm, LD: 8.1 ± 4.4 mGy*cm, p < 0.01) and the interventional guidance scans (SD: 43.0 ± 48.8 mGy*cm, LD: 18.4 ± 7.3 mGy*cm, p < 0.01). Image quality, contrast, determination of the target structure, and confidence for planning or intervention guidance were rated good to perfect for SD and LD scans, showing no statistically significant differences between SD and LD scans (p > 0.05). Image noise was similar between SD and LD scans performed for planning of the interventional procedures (SD: 14.62 ± 2.83 HU vs. LD: 15.45 ± 3.22 HU, p = 0.24). Use of a LD protocol for MDCT-guided biopsies along the spine is a practical alternative, maintaining overall image quality and confidence. Increasing availability of model-based iterative reconstruction in clinical routine may facilitate further radiation dose reductions.

A Combined Scoring Method Based on 18F-FDG PET/CT for Distinguishing Spinal Infection From Malignancy

STUDY DESIGN

Retrospective study.

OBJECTIVE

This study aimed to explore the additional value of fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for the detection of early-stage and atypical spinal infections and to find the best combination of indicators from laboratory and imaging systems for higher diagnostic efficiency.

SUMMARY OF BACKGROUND DATA

Diagnosis of early-stage and atypical spinal infections may be challenging for clinicians. It is particularly important to distinguish spinal infection from malignancy to develop a timely treatment strategy and avoid unnecessary biopsy or surgery.

MATERIALS AND METHODS

All patients with a discharge diagnosis of spinal infection or malignancy who underwent 18F-FDG PET/CT scans before spinal biopsy between January 1, 2014, and July 30, 2021, were included. Laboratory and imaging data were assessed. A receiver operating characteristic (ROC) curve was created, and the best cut-off point and cumulated area under the curve (AUC) were obtained to distinguish between spinal infection and malignancy. Kappa values were used to assess the agreement between the 18F-FDG PET/CT and MRI findings. Binary logistic regression was used to screen for statistically significant indicators and imaging findings.

RESULTS

A total of 71 patients with confirmed spinal infections (n=30) or malignancies (n=41) were included in this study. Elevated ESR and significantly elevated tumor biomarkers or positive FLCs assay were significantly different between the two groups. In addition to the total lesion glycolysis of the involved vertebral bodies derived from 18F-FDG PET/CT, four imaging findings (consecutive multilevel vertebral lesions, intervertebral disc, vertebral arch, and extraspinal involvement) also showed significant differences between the two groups (P≤0.010). A combined scoring method based on the above seven indicators was designed with an overall classification accuracy of 95.2%, and it identified all patients with spinal infections (100%, 28/28). In addition, moderate-to-excellent agreement could be reached for the involvement of intervertebral discs, paravertebral soft tissues, and vertebral arches derived from MRI and18F-FDG PET/CT.

CONCLUSIONS

The combined scoring method based on 18F-FDG PET/CT provided excellent overall accuracy in distinguishing spinal infections from malignancies. This approach may prove useful for patients with MRI contraindications or with equivocal results following laboratory tests or traditional imaging when there is high suspicion for spinal infections or malignancy.

Management of Chordoma of the Sacrum and Mobile Spine

➢

Chordomas account for 1% to 4% of primary tumors of the spine and sacrum.

➢

En bloc resection is the preferred surgical treatment for the management of chordomas.

➢

Proton beam radiation is increasingly being used as a postoperative radiation modality for the treatment of chordomas.

C-arm Fluoroscopy-Guided Percutaneous Needle Biopsy for the Diagnosis of Spinal Infection: A Study of 203 Consecutive Patients

C-arm fluoroscopy-guided percutaneous needle biopsy (PNB) is a commonly used biopsy method, which shows similar diagnostic outcomes to CT-guided biopsy. This study aimed to evaluate the diagnostic value of C-arm fluoroscopy-guided percutaneous needle biopsy (PNB) for spinal infection. A total of 30 male and 73 female patients with suspected spinal infection were enrolled. Among enrolled patients, the spinal lesion was mainly located in the thoracic (T3-T12, 48.28%) and lumbar vertebra (L1-L5, 46.80%), and T12 was the most frequently involved site. C-arm fluoroscopy-guided PNB was performed for the isolation of biopsy samples in these patients. The overall detection rate of pathological changes in bone tissues was 94.1% (191/203), including 92 granulomata with caseous necrosis, 81 inflammatory tissues, 18 tumor tissues, and 12 bone tissues without visible pathological changes. After excluding the tumors, the detection rate of pathogenic microorganisms in liquid tissues was 50.27% (93/185), including 68 Mycobacterium tuberculosis, and 25 other microorganisms. Spinal tuberculosis was diagnosed in 118 (58%) cases, and nonspecific spinal infection with microorganisms other than Mycobacterium tuberculosis was diagnosed in 25 (12.7%) cases. Definite diagnosis was not determined in the left 42 (20.5%) patients with neither positive pathological nor pathogenic results. C-arm fluoroscopy-guided PNB is effective in the detection of pathological changes and pathogenic microorganisms, which is a practical approach for the diagnosis of spinal infection with high accuracy.

Transnasal Endoscopic and Transoral Approaches in the Biopsies of Ventral Atlas and Axis Vertebrae: A Comprehensive Retrospective Study for Preprocedural Scheme, Biopsy Procedure, Core Technique Analysis, Diagnostic Yield and Clinical Outcome

OBJECTIVE

This study aims to describe and analyze the transoral and transnasal approaches for pathologies of the ventral atlas and axis vertebrae, which are considered technically challenging regions for diagnostic biopsy.

METHODS

A series of transnasal endoscopic approach (TNA) and transoral approach (TOA) biopsies for the pathologies of the first and second cervical vertebrae were conducted and retrospectively analyzed from July 2014 to May 2021. The depth of the biopsy trajectory was measured on computed tomography images for all nine patients (eight males and one female with an average age of 58.11 ± 11.60 years), as were the coronal, sagittal, and vertical biopsy safe ranges. The characteristics of each lesion, including radiographic features, blood supply, and destruction of anterior or posterior vertebral body edges, were evaluated to guide the biopsy. Four biopsy core techniques (BCTs), including "lesion perforating", "aspiration", "cutting-and-scraping" and "biopsy forceps utilization" were elaborated in this study. The biopsy procedures and periprocedural precautions were demonstrated. Patient demographics, clinical data, lesion characteristics, diagnostic yield, and complications were recorded for each case.

RESULTS

Eight TOA biopsies for the axis vertebral body and one TNA biopsy for the atlas anterior arch were successfully performed and yielded adequate pathologies. All biopsies were organized based on the preprocedural radiographic measurements, which showed that the average length of biopsy trajectory and coronal, sagittal, and vertical safe biopsy ranges were 85.00 ± 5.88, 20.63 ± 4.75, 16.25 ± 1.49, and 24.63 ± 2.26 mm, respectively, and these corresponding data were 95, 36, 9, and 26 mm in the TNA patient. Six osteolytic lesions (66.7%), one osteoblastic lesion (11.1%), and two mixed lesions (22.2%) were observed, among which seven lesions had a rich blood supply. Biopsy forceps and core needles were utilized to obtain samples in six and three patients, respectively. All the TNA and TOA biopsies were performed with cooperative application of multiple BCTs under compound anatomic and stereotactic navigations. Intraprocedural or postprocedural complications occurred in no patients who underwent the biopsy in the follow-up period (1-39 months). No significant differences were found between the preprocedural and postprocedural blood indexes and visual analogue scale scores.

CONCLUSION

With a sophisticated preprocedural arrangement, cooperative application of BCTs, and careful periprocedural precautions, transnasal endoscopic and transoral biopsies are two feasible, efficient, and well-tolerated procedures that achieve satisfactory diagnostic yield, complication rate, and clinical outcome.

Percutaneous CT-Guided Biopsy of the Craniovertebral Junction: Safety, Diagnostic Yield, and Technical Notes

The craniovertebral junction defined as the occiput, the atlas, and the axis is a complex bony region that contains vital neural and vascular structures. We report the experience of a single academic institution regarding CT-guided biopsy of this skeletal region. We reviewed all of the CT-guided biopsies performed in our department, completed in the craniovertebral junction. We collected data in regard to biopsy procedures, patients’ vital statistics, and histopathological diagnosis. In total, 16 patients (8M and 8F; mean age 52; range 16–86 years old) were included in this series. In eight patients, the lesions were located in the atlas vertebra (8/16—50%), in six patients in the axis (37.5%), and in two patients in the occiput (12.5%). No complications were observed during or after the procedures. All of the procedures were technically successful. The biopsy was diagnostic in 13/16 patients (81.3%): four metastatic lesions (25%—three breast and one prostate cancers), four multiple myeloma bone lesions (25%), three aneurismal bone cysts (18.8%), one aggressive hemangioma (6.3%), and one pseudogout (6.3%). Moreover, in two-thirds (66.6%) of non-diagnostic histological reports, malignancies were excluded. CT-guided percutaneous biopsy is a safe tool and allows obtaining a histological diagnosis, in most cases, even in the most delicate site of the human skeleton—the craniovertebral junction.

Diagnostic Accuracy and Adequacy of Computed Tomography Versus Fluoroscopy-Guided Percutaneous Transpedicular Biopsy of Spinal Lesions

Background

Transpedicular biopsy of spinal lesions is imperative for the generation of a definite diagnosis. Thus far, literature comparing the accuracy and adequacy between fluoroscopy-guided and computed tomography (CT)-guided transpedicular biopsy of spinal lesions is scarce. We aim to compare the accuracy and adequacy of samples collected with the two techniques at the largest tertiary hospital in Malaysia.

Materials and methods

A total of 60 patients (37 patients with spinal infection and 23 patients with spinal tumour) underwent percutaneous transpedicular biopsy of spinal lesions from January 2013 to December 2017 at a tertiary centre. Demographic data, biopsy method (fluoroscopy-guided and CT-guided), diagnosis, adequacy, and accuracy of samples obtained were assessed.

Results

Among the 60 samples obtained, only two samples (3.3%) were deemed inadequate. There were 10 biopsy samples (16.7%) that were inaccurate. There was no statistical difference between fluoroscopy-guided and CT-guided transpedicular biopsy in terms of accuracy (p = 0.731) and adequacy (p = 0.492).

Conclusions

Fluoroscopy-guided and CT-guided transpedicular biopsy of spinal lesions offer similar accuracy and adequacy. Fluoroscopy-guided biopsy of the spinal lesion will be an option for spine surgeons when CT-guided biopsy is not available.

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.