A clinical prediction model to differentiate tuberculous spondylodiscitis from pyogenic spontaneous spondylodiscitis.

BACKGROUND: Microbiological diagnosis of tuberculous spondylodiscitis (TS) and pyogenic spontaneous spondylodiscitis (PS) is sometime difficult. This study aimed to identify the predictive factors for differentiating TS from PS using clinical characteristics, radiologic findings, and biomarkers, and to develop scoring system by using predictive factors to stratify the probability of TS. METHODS: A retrospective single-center study. Demographics, clinical characteristics, laboratory findings and radiographic findings of patients, confirmed causative pathogens of PS or TS, were assessed for independent factors that associated with TS. The coefficients and odds ratio (OR) of the final model were estimated and used to construct the scoring scheme to identify patients with TS. RESULTS: There were 73 patients (51.8%) with TS and 68 patients (48.2%) with PS. TS was more frequently associated with younger age, history of tuberculous infection, longer duration of symptoms, no fever, thoracic spine involvement, ≥3 vertebrae involvement, presence of paraspinal abscess in magnetic-resonance-image (MRI), well-defined thin wall abscess, anterior subligamentous abscess, and lower biomarker levels included white blood cell (WBC) counts, erythrocyte-sedimentation-rate (ESR), neutrophil fraction, and C-reactive protein (all p < 0.05). Multivariate logistic regression analysis revealed significant predictors of TS included WBC ≤9,700/mm3 (odds ratio [OR] 13.11, 95% confidence interval [CI] 4.23-40.61), neutrophil fraction ≤78% (OR 4.93, 95% CI 1.59-15.30), ESR ≤92 mm/hr (OR 4.07, 95% CI 1.24-13.36) and presence of paraspinal abscess in MRI (OR 10.25, 95% CI 3.17-33.13), with an area under the curve of 0.921. The scoring system stratified the probability of TS into three categories: low, moderate, and high with a TS prevalence of 8.1%, 29.6%, and 82.2%, respectively. CONCLUSIONS: This prediction model incorporating WBC, neutrophil fraction counts, ESR and presence of paraspinal abscess accurately predicted the causative pathogens. The scoring scheme with combination of these biomarkers and radiologic features can be useful to differentiate TS from PS.

The comparisons between thermography and ultrasonography with physical examination for wrist joint assessment in juvenile idiopathic arthritis.

OBJECTIVE: This study aimed to assess infrared thermography (IRT) and ultrasonography (US) for detecting wrist arthritis in juvenile idiopathic arthritis (JIA) patients. Although IRT could help us in detecting joint inflammation, IRT studies in JIA patients with wrist arthritis are still limited. Currently, no validated US criteria exist for detecting arthritis, and the most useful parameters between gray-scale ultrasound (GSUS) or power Doppler ultrasound (PDUS) remain unclear. APPROACH: Forty-six JIA patients were included in this study. Detecting wrist arthritis at varying degrees using IRT and US were compared with physical examination. MAIN RESULTS: Sixteen patients had previous wrist arthritis that is currently inactive and 30 still had wrist arthritis. The median ages (IQR) were 7.7 (4.3) and 10.2 (4.8) years, respectively. Fifteen healthy participants were included, with a median age (IQR) of 9.2 (2.0) years. Using IRT, mean temperature (T mean) and maximum temperature (T max) at skin surface in the region of interest (ROI) in the arthritis group were higher than in the inactive group and the healthy controls with p < 0.05. When patients with arthritis were subgroup analyzed by disease severity based on physical examination, the moderate to severe arthritis had T mean and T max higher than the mild arthritis group with statistical significance. The heat distribution index (HDI), two standard deviations of all pixel temperature values in the ROI, in the moderate to severe arthritis group was higher than in the healthy controls (p = 0.027). The receiver operating characteristic analysis in arthritis detection revealed diagnostic sensitivity of 85.7% and 71.4% and specificity of 80.0% and 93.3% at cut-off points of T mean ⩾ 31.0 °C and T max ⩾ 32.3 °C, respectively. For US, GSUS and PDUS are useful in detecting arthritis, providing high sensitivity (83.3%) and specificity (81.3%). SIGNIFICANCE: Our study demonstrated that both IRT and US were applicable tools for detecting wrist arthritis.

Ultrasound of the Knee: Common Pathology Excluding Extensor Mechanism.

Ultrasound can be used to diagnose many types of pathology and guide various diagnostic or therapeutic procedures. The most common applications for musculoskeletal ultrasound of the knee include evaluation of the joint recesses, the extensor mechanism, and bursae including Baker's cyst. However, a role exists for ultrasound in the evaluation of cartilage, other tendons, ligaments, peripheral nerves, osseous structures, and vasculature. This article reviews common pathologies of these structures as seen with ultrasound. In addition, various ultrasound-guided procedures pertaining to these pathologies are introduced. The importance of a comprehensive evaluation is also emphasized as a method to maximize information gained from the ultrasound examination.

Ultrasound evaluation of bursae: anatomy and pathological appearances.

A bursa is an extra-articular sac that may communicate with a joint and functions to decrease friction between tendons and either bone or skin. Bursae can be classified as native and non-native (adventitious) bursae. The native bursae are lined with a synovial membrane and occur at predictable anatomical sites; knowledge of these normal structures can help distinguish them from other pathological entities. An adventitious bursa can form at sites of friction rather than at predictable anatomical sites, but otherwise have imaging features similar to native bursae. Bursal distention can occur from many pathological processes, most commonly resulting from chronic overuse injury. When imaging bursal pathological conditions, there is often an overlap of imaging findings, regardless of the cause. In general, ultrasound of a distended bursa reveals a fluid collection with either simple anechoic or more complex hypoechoic fluid. Bursal distention is characteristically unilocular and compressible, unlike other structures such as ganglion cysts, which are usually multilocular and non-compressible. This article reviews the anatomical locations of common bursae and shows pathological examples using ultrasound. Knowledge of typical locations and imaging appearances of bursae can aid in narrowing the differential diagnosis and guiding further management and treatment decisions.

New Techniques in MR Imaging of the Ankle and Foot.

Foot and ankle disorders are common in everyday clinical practice. MR imaging is frequently required for diagnosis given the variety and complexity of foot and ankle anatomy. Although conventional MR imaging plays a significant role in diagnosis, contemporary management increasingly relies on advanced imaging for monitoring therapeutic response. There is an expanding need for identification of biomarkers for musculoskeletal tissues. Advanced imaging techniques capable of imaging these tissue substrates will be increasingly used in routine clinical practice. Radiologists should therefore become familiar with these innovative MR techniques. Many such techniques are already widely used in other organ systems.

Solitary subcutaneous sarcoidosis with massive chronic prepatellar bursal involvement.

A 56-year-old man presented with a painless prepatellar mass of the left knee. MR images demonstrated a large, well-defined mass with heterogeneous intermediate signal intensity on T1- and proton density-weighted images. Mild, heterogeneous enhancement was noted after the intravenous administration of gadolinium. Diagnostic imaging included atypical soft-tissue infection, fibrogranulomatous reaction, gouty tophus, rheumatoid nodule and xanthoma or possibly malignancy. The histopathological examination revealed sarcoidosis involving the prepatellar bursa.

MR morphology of triangular fibrocartilage complex: correlation with quantitative MR and biomechanical properties.

OBJECTIVE: To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high-resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. MATERIALS AND METHODS: Five cadaveric wrists (22-70 years) were imaged at 3 T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. RESULTS: On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. CONCLUSION: These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques.