Radiological Assessment of Charcot Neuro-Osteoarthropathy in Diabetic Foot: A Narrative Review

Charcot Neuro-Osteoarthropathy (CNO) is a debilitating complication predominantly affecting individuals with diabetes and peripheral neuropathy. Radiological assessment plays a central role in the diagnosis, staging, and management of CNO. While plain radiographs remain the cornerstone of initial imaging, advanced modalities such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) have significantly enhanced diagnostic accuracy. Nuclear imaging, including bone scintigraphy, radiolabeled leukocyte scans, and FDG-PET/CT, offers additional diagnostic precision in complex cases, especially when differentiating CNO from infections or evaluating patients with metal implants. This review underscores the importance of a multimodal imaging approach suited to the clinical stage and specific diagnostic challenges of CNO. It highlights the critical need for standardized imaging protocols and integrated diagnostic algorithms that combine radiological, clinical, and laboratory findings. Advances in imaging biomarkers and novel techniques such as diffusion-weighted MRI hold promise for improving early detection and monitoring treatment efficacy. In conclusion, the effective management of CNO in diabetic foot patients requires a multidisciplinary approach that integrates advanced imaging technologies with clinical expertise. Timely and accurate diagnosis not only prevents debilitating complications but also facilitates the development of personalized therapeutic strategies, ultimately improving patient outcomes.

Diagnosing osteomyelitis in diabetic foot by diffusion-weighted imaging and dynamic contrast material-enhanced magnetic resonance imaging: a systematic review and meta-analysis

AIM

To evaluate the diagnostic performance of diffusion-weighted imaging (DWI) and dynamic contrast enhanced (DCE), for diagnosing osteomyelitis in the diabetic foot.

MATERIALS AND METHODS

A thorough search was carried out to identify suitable studies published up to September 2023. The quality of the studies involved was evaluated using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). The diagnostic sensitivity and specificity of each imaging modality/method for each specific cut point were summarized. The summary receiver operating characteristic (SROC) curve was calculated using bivariate mixed effects models.

RESULTS

Five studies investigating 187 patients and 234 bone lesions with 110 diagnosed osteomyelitis were enrolled. Four studies used DWI (172 lesions), three studies used DCE techniques (140 lesions) and two studies presented results of conventional MRI (66 lesions). The sensitivity ranges using conventional MRI, DWI and DCE were 65%-100%, 65%-100% and 64%-100%, respectively. The specificity ranges were 50%-61%, 56%-95%, and 66%-93%, respectively. The SROC curve of DWI and DCE was 0.89 (95% CI, 0.86-0.92) and 0.90 (95% CI, 0.87-0.92), respectively.

CONCLUSION

Combining DWI and DCE methods, alongside conventional MRI, can improve the reliability and accuracy of diabetic foot osteomyelitis diagnosis. However, the study recognizes result variability due to varying protocols and emphasizes the need for well-designed studies with standardized approaches. To optimize diagnostic performance, the study recommends considering low ADC values, Ktrans or rapid wash-in rate from DCE such as iAUC60, along with using large ROIs that cover the entire lesion while excluding normal bone marrow.

Musculoskeletal infections through direct inoculation

Musculoskeletal infections consist of different clinical conditions that are commonly encountered in daily clinical settings. As clinical findings and even laboratory tests cannot always be specific, imaging plays a crucial role in the diagnosis and treatment of these cases. Musculoskeletal infections most commonly occur secondary to direct inoculation into the skin involuntarily affected by trauma, microorganism, foreign bodies, or in diabetic ulcers; direct infections can also occur from voluntary causes due to surgery, vaccinations, or other iatrogenic procedures. Hematogenous spread of infection from a remote focus can also be a cause for musculoskeletal infections. Risk factors for soft tissue and bone infections include immunosuppression, old age, corticosteroid use, systemic illnesses, malnutrition, obesity, and burns. Most literature discusses musculoskeletal infections according to the diagnostic tools or forms of infection seen in different soft tissue anatomical planes or bones. This review article aims to evaluate musculoskeletal infections that occur due to direct inoculation to the musculoskeletal tissues, by focusing on the traumatic mechanism with emphasis on the radiological findings.

Imaging of lower extremity infections: predisposing conditions, atypical infections, mimics, and differentiating features

Imaging evaluation for lower extremity infections can be complicated, especially in the setting of underlying conditions and with atypical infections. Predisposing conditions are discussed, including diabetes mellitus, peripheral arterial disease, neuropathic arthropathy, and intravenous drug abuse, as well as differentiating features of infectious versus non-infectious disease. Atypical infections such as viral, mycobacterial, fungal, and parasitic infections and their imaging features are also reviewed. Potential mimics of lower extremity infection including chronic nonbacterial osteomyelitis, foreign body granuloma, gout, inflammatory arthropathies, lymphedema, and Morel-Lavallée lesions, and their differentiating features are also explored.

How to do and evaluate DWI and DCE-MRI sequences for diabetic foot assessment

MRI evaluation of the diabetic foot is still a challenge not only from an interpretative but also from a technical point of view. The incorporation of advanced sequences such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI into standard protocols for diabetic foot assessment could aid radiologists in differentiating between neuropathic osteoarthropathy (Charcot's foot) and osteomyelitis. This distinction is crucial as both conditions can coexist in diabetic patients, and they require markedly different clinical management and have distinct prognoses. Over the past decade, several studies have explored the effectiveness of DWI and dynamic contrast-enhanced MRI (DCE-MRI) in distinguishing between septic and reactive bone marrow, as well as soft tissue involvement in diabetic patients, yielding promising results. DWI, without the need for exogenous contrast, can provide insights into the cellularity of bone marrow and soft tissues. DCE-MRI allows for a more precise evaluation of soft tissue and bone marrow perfusion compared to conventional post-gadolinium imaging. The data obtained from these sequences will complement the traditional MRI approach in assessing the diabetic foot. The objective of this review is to familiarize readers with the fundamental concepts of DWI and DCE-MRI, including technical adjustments and practical tips for image interpretation in diabetic foot cases.

Approach to Charcot Neuroarthropathy of the Great Toe: A Case Report

Charcot neuroarthropathy (CN) is a chronic progressive debilitating disease affecting joints, bone and soft tissue of an insensate limb, usually seen in patients with diabetes. CN of the great toe is rare or it may be associated with CN of other joints. Only a few cases have been reported on the CN of the great toe. Stabilization and offloading is the primary aim of the treatment of CN. The present case report highlights the presentation, diagnosis and management of CN of the great toe. A 56-year-old male patient with diabetes presented to our outpatient department with post-traumatic swelling of the great toe with blackish discoloration and scanty, purulent discharging sinus. Based on the clinical and radiological findings, it was diagnosed to be the CN of the great toe, which was stabilized with a Kirschner wire. Clinical improvement and new bone formation were seen and the great toe was stabilized in acceptable alignment. Diagnosing CN of the great toe is challenging and needs both clinical and radiological evaluation. Stabilization with a single Kirschner wire is a simple, low-cost procedure, which can be done under a digital block in a minor operation theatre. Immediate mobilization and weight-bearing are allowed with good radiological and functional outcomes.

Differential Diagnosis of Diabetic Foot Osteomyelitis and Charcot Neuropathic Osteoarthropathy with Deep Learning Methods

Our study aims to evaluate the potential of a deep learning (DL) algorithm for differentiating the signal intensity of bone marrow between osteomyelitis (OM), Charcot neuropathic osteoarthropathy (CNO), and trauma (TR). The local ethics committee approved this retrospective study. From 148 patients, segmentation resulted in 679 labeled regions for T1-weighted images (comprising 151 CNO, 257 OM, and 271 TR) and 714 labeled regions for T2-weighted images (consisting of 160 CNO, 272 OM, and 282 TR). We employed both multi-class classification (MCC) and binary-class classification (BCC) approaches to compare the classification outcomes of CNO, TR, and OM. The ResNet-50 and the EfficientNet-b0 accuracy values were computed at 96.2% and 97.1%, respectively, for T1-weighted images. Additionally, accuracy values for ResNet-50 and the EfficientNet-b0 were determined at 95.6% and 96.8%, respectively, for T2-weighted images. Also, according to BCC for CNO, OM, and TR, the sensitivity of ResNet-50 is 91.1%, 92.4%, and 96.6% and the sensitivity of EfficientNet-b0 is 93.2%, 97.6%, and 98.1% for T1, respectively. For CNO, OM, and TR, the sensitivity of ResNet-50 is 94.9%, 83.6%, and 97.9% and the sensitivity of EfficientNet-b0 is 95.6%, 85.2%, and 98.6% for T2, respectively. The specificity values of ResNet-50 for CNO, OM, and TR in T1-weighted images are 98.1%, 97.9%, and 94.7% and 98.6%, 97.5%, and 96.7% in T2-weighted images respectively. Similarly, for EfficientNet-b0, the specificity values are 98.9%, 98.7%, and 98.4% and 99.1%, 98.5%, and 98.7% for T1-weighted and T2-weighted images respectively. In the diabetic foot, deep learning methods serve as a non-invasive tool to differentiate CNO, OM, and TR with high accuracy.

Approach to imaging modalities in the setting of suspected infection

Imaging plays an important role in the workup of musculoskeletal infection, in conjunction with clinical history and physical exam. There are multiple imaging modalities that can be of clinical utility in the setting of suspected infection, each with their own benefits and limitations. Radiography is a low-cost, accessible modality providing a broad osseous overview, but can be insensitive for early osteomyelitis. Ultrasound plays a more limited role in the workup of musculoskeletal infection, but can be useful in the pediatric population or for real-time guidance for joint and soft tissue aspirations. Computed tomography (CT) plays an important role in the timely and accurate diagnosis of critically ill patients in the emergency setting. Its superior soft tissue characterization allows for diagnosis of abscesses, and it can help confirm the clinical diagnosis of necrotizing fasciitis when soft tissue gas is present. Magnetic resonance imaging (MRI) is often the modality of choice in the diagnosis of infection, as its superior contrast resolution allows for clear delineation of the presence and extent of both soft tissue infection and osteomyelitis. Additionally, the use of intravenous contrast and advanced imaging sequences such as diffusion weighted imaging (DWI) further increases the diagnostic utility of MRI in the assessment for infection. Familiarity with the diagnostic utility of each imaging modality will allow the radiologist to appropriately guide imaging workup in the setting of clinically suspected infection.

Magnetic Resonance Imaging and 99Tc WBC-SPECT/CT Scanning in Differential Diagnosis between Osteomyelitis and Charcot Neuroarthropathy: A Case Series

BACKGROUND

Distinguishing between Charcot Neuroarthropathy (CN), osteomyelitis (OM), and CN complicated with superimposed OM in diabetic patients is crucial for the treatment choice. Given that current diagnostic methods lack specificity, advanced techniques, e.g., magnetic resonance imaging (MRI) and 99mTc-HMPAO-WBC Single Photon Emission Computed Tomography (SPECT/CT), are needed. This study addresses the challenges in distinguishing OM and CN.

METHODS

We included diabetic patients with CN and soft tissue ulceration. MRI and 99mTc-HMPAO-WBC SPECT/CT were used for the diagnosis. The patients were classified into three probability levels for OM (i.e., Definite, Probable, and Unlikely) according to the Consensus Criteria for Diabetic Foot Osteomyelitis (CC-DFO).

RESULTS

Eight patients met the eligibility criteria. MRI, supported by SPECT-CT and CC-DFO, showed consistency with the OM diagnosis in three cases. The key diagnostic features included the location of signal abnormalities and secondary features such as skin ulcers, sinus tracts, and abscesses. Notably, cases with inconclusive MRI were clarified by SPECT/CT, emphasizing its efficacy in challenging scenarios.

CONCLUSIONS

The primary objective of this study was to compare the results of MRI and 99mTc-HMPAO-WBC SPECT/CT with the CC-DFO score in the diabetic foot with CN and suspected OM. Advanced imaging offers a complementary approach to distinguish between CN and OM. This can help delineate the limits of the disease for presurgical planning. While MRI is valuable, 99mTc-HMPAO-WBC SPECT/CT provides additional clarity, especially in challenging cases or when metallic implants affect MRI accuracy.

Radiomics method in the differential diagnosis of diabetic foot osteomyelitis and charcot neuroarthropathy

OBJECTIVES

Our study used a radiomics method to differentiate bone marrow signal abnormality (BMSA) between Charcot neuroarthropathy (CN) and osteomyelitis (OM).

METHODS AND MATERIALS

The records of 166 patients with diabetic foot suspected CN or OM between January 2020 and March 2022 were retrospectively examined. A total of 41 patients with BMSA on MRI were included in this study. The diagnosis of OM was confirmed histologically in 24 of 41 patients. We clinically followed 17 patients as CN with laboratory tests. We also included 29 nondiabetic patients with traumatic (TR) BMSA on MRI as the third group. Contours of all BMSA on T 2 - and T1 -weighted images in three patient groups were segmented semi-automatically on ManSeg (v.2.7d). The T1 and T2 features of three groups in radiomics were statistically evaluated. We applied the multi-class classification (MCC) and binary-class classification (BCC) methodologies to compare results.

RESULTS

For MCC, the accuracy of Multi-Layer Perceptron (MLP) was 76.92% and 84.38% for T1 and T2, respectively. According to BCC, for CN, OM, and TR BMSA, the sensitivity of MLP is 74%, 89.23%, and 76.19% for T1, and 90.57%, 85.92%, 86.81% for T2, respectively. For CN, OM, and TR BMSA, the specificity of MLP is 89.16%, 87.57%, and 90.72% for T1 and 93.55%, 89.94%, and 90.48% for T2 images, respectively.

CONCLUSION

In diabetic foot, the radiomics method can differentiate the BMSA of CN and OM with high accuracy.

ADVANCES IN KNOWLEDGE

The radiomics method can differentiate the BMSA of CN and OM with high accuracy.

Imaging of the Diabetic Foot

Diabetic foot complications are increasingly prevalent in the world, leading to significant morbidity and driving up associated health care costs. Complex pathophysiology and suboptimal specificity of current imaging modalities have made diagnosis challenging, mainly in the evaluation of superimposed foot infection to underlying arthropathy or other marrow lesions. Recent advances in radiology and nuclear medicine have the potential to streamline the assessment of diabetic foot complications. But we must be aware of the specific strengths and weaknesses of each modality, and their applications. This review offers a comprehensive approach to the spectrum of diabetic foot complications and their imaging appearances in conventional and advanced imaging studies, including optimal technical considerations for each technique. Advanced magnetic resonance imaging (MRI) techniques are highlighted, illustrating their complementary role to conventional MRI, in particular their potential impact in avoiding additional studies.

Diffusion-weighted MR imaging and utility of ADC measurements in characterizing nerve and muscle changes in diabetic patients on ankle DWI studies: a cross-sectional study

OBJECTIVE

To evaluate the utility of apparent diffusion coefficient (ADC) measurements from ankle MRI diffusion-weighted imaging (DWI) studies in identifying neuropathic changes in diabetic patients.

METHODS

In total, 109 consecutive ankle MRI scans (n = 101 patients) at a single tertiary care county hospital from November 1, 2019, to July 11, 2021, who met the inclusion criteria were identified. Patients were divided into 2 cohorts: diabetic (n = 62) and non-diabetic (n = 39). Demographics, HgbA1c, neuropathy diagnosis, and image quality data were collected. Abductor hallucis (AH) ADC mean and minimum (min) values and posterior tibial nerve (PTN) ADC mean and minimum values were measured. Student t-test and Pearson's correlation coefficient analysis were performed using R.

RESULTS

Diabetic patients had significantly higher mean and min ADC values (× 10^-3 mm²/s) of the AH muscle (mean: 1.77 vs 1.39, p < 0.001; min: 1.51 vs 1.06, p < 0.001) and PTN (mean: 1.65 vs 1.18, p < 0.001; min: 1.33 vs 0.95, p < 0.001) compared to non-diabetic patients. HgbA1c positively correlated with AH and PTN ADC mean values (AH: p = 0.036; PTN: p = 0.004).

CONCLUSION

Our data suggests that an increasing diffusivity of water as quantified by ADC across neuronal and muscular membranes is a consequence of the pathophysiology of the disease. Thus, ankle MRI-DWI studies are useful in identifying neuropathic changes in diabetic patients and quantifying the severity noninvasively.

KEY POINTS

• Diabetic patients had significantly higher mean and minimum ADC values of the abductor hallucis muscle and posterior tibial nerve compared to non-diabetic patients. • HgbA1c positively correlated with ADC mean values (AH: p = 0.036; PTN: p = 0.004) suggesting that an increasing diffusivity of water across neuronal and muscular membranes is a consequence of the pathophysiology of diabetic neuropathy. • Ankle MRI DWI can be used clinically to non-invasively identify neuropathic changes due to diabetes mellitus.

Characterizing conventional ankle MRI findings of nerve and muscle changes in diabetic patients: a case-control study

BACKGROUND

Foot and ankle amputation is a feared complication of diabetic neuropathy and diabetes mellitus (DM) accounts for 80% of all in-hospital amputations. Magnetic resonance neurography is an effective tool in characterizing neuromuscular sequelae of the disease. However, conventional ankle MRI is more commonly performed and has not been studied to assess neuromuscular changes of DM.

OBJECTIVE

The objective is to characterize neuromuscular changes of diabetic patients in a case-control study using conventional ankle MRI.

METHODS

Between November 2019 and July 2021, 110 consecutive ankle MRI scans (n = 102 patients) at our county hospital were reviewed and met the inclusion criteria. Patients were divided into two cohorts, diabetic (N = 63) and non-diabetic (N = 39). Demographics, HgbA1c, and reason for MRI study were collected via retrospective chart review. The presence of intramuscular edema-like signal, pattern of the edema, muscle fatty infiltration, and measurements of the cross-sectional area of the posterior, medial, and lateral tibial nerves (PTN, MPN, and LPN) was recorded blinded to the clinical findings by two readers.

RESULTS

Muscle edema-like signal was much more likely to be found in DM (odds ratio 19.5, 95% CI 7.0-54.6, p < 0.001). DM also showed increase of 0.87 in the mean grade of muscle fatty infiltration (p < 0.001). There were higher rates of nerve T2 hyperintensity (odds ratio 14.0, 95% CI 3.1-62.7, p < 0.001) and the measured areas of the PTN, MPN, and LPN were also larger in DM compared to their non-diabetic counterparts (PTN: 0.16 cm² vs. 0.10 cm², p < 0.01; MPN: 0.09 cm² vs. 0.05 cm², p < 0.01; LPN: 0.07 cm² vs. 0.04 cm², p < 0.05).

CONCLUSION

Conventional ankle MRIs can be used to detect DM-related neuromuscular changes.

Hybrid imaging of Diabetic Foot Infections

Diabetic foot infections, a common but diagnostically challenging clinical presentation, requires the difficult differentiation between soft tissue-only infection, diabetic neuropathic osteoarthropathy, osteomyelitis or a combination of these pathological processes. While there are clinical predictors for osteomyelitis and simple bedside tests available, imaging is often required for accurate diagnosis. A variety of anatomic and molecular imaging tests are in clinical use, each with its advantages and disadvantages. This review will provide an overview of the different available imaging modalities and their diagnostic criteria, emphasizing the role of hybrid imaging for the accurate diagnosis of osteomyelitis.

A Rare Charcot Neuro-Osteoarthropathy of Hip with an Uncommon Cause

Neuro-osteoarthropathy often called as Charcot joint results from decreased sensory innervations of the involved joint resulting in severely damaged and disrupted joints and involvement of adjacent soft tissues. Charcot joint is characterized by the “6Ds,” which are i) distended joints, ii) density increase, iii) debris production, iv) dislocation, v) disorganization, and vi) destruction. Hip joint involvement is very rare probably because of rich nerve supply compared with other peripheral joints. To minimize the joint deformity and loss of function, early diagnosis is of great importance in which radiological imaging plays a major role.

Presurgical Perspective and Postsurgical Evaluation of the Diabetic Foot

Management of the diabetic foot is complex and challenging, requiring a multidisciplinary approach. Imaging plays an important role in the decision-making process regarding surgery. This article discusses the presurgical perspective and postsurgical evaluation of the diabetic foot.

Diffusion-Weighted Imaging Distinguishes Between Osteomyelitis, Bone Marrow Edema, and Healthy Bone on Forefoot Magnetic Resonance Imaging

BACKGROUND

Diagnosis of osteomyelitis by imaging can be challenging. The feasibility of diffusion-weighted imaging (DWI) as ancillary sequence was evaluated in this study.

PURPOSE

To evaluate DWI for differentiation between osteomyelitis, bone marrow edema, and healthy bone on forefoot magnetic resonance imaging (MRI).

STUDY TYPE

Prospective.

SUBJECTS

A total of 60 consecutive patients undergoing forefoot MRI divided into three study groups (20 subjects each): osteomyelitis, bone marrow edema, and healthy bone.

FIELD STRENGTH/SEQUENCE

A 1.5T and 3T MRI scanners; readout-segmented multishot echo planar DWI.

ASSESSMENT

Two independent radiologists measured apparent diffusion coefficient (ADC) values within abnormal or healthy bone.

STATISTICAL TESTS

ADC values were compared between groups (pairwise t-test with Bonferroni-Holm correction for multiple testing). Intraclass correlation coefficient (ICC) was calculated to assess inter-reader agreement. Threshold ADC values were determined as the cutoffs that maximized the sum of sensitivity and specificity. Receiver operating characteristic (ROC) analysis was performed with statistical threshold of P < 0.05.

RESULTS

Inter-reader agreement was 0.92 in the healthy bone group and 0.78 in both the edema and osteomyelitis groups. Average ADC values were significantly different between groups: 1432 ± 222 × 10^-6  mm² /sec (osteomyelitis), 1071 ± 196 × 10^-6  mm² /sec (bone marrow edema), and 277 ± 89 × 10^-6  mm² /sec (healthy bone). A threshold ADC value of 534 × 10^-6  mm² /sec distinguishes between healthy and abnormal bone with specificity and sensitivity of 100% each. For distinction between osteomyelitis and bone marrow edema, two cutoff values were determined: a 95%-specificity cutoff indicating osteomyelitis (>1320 × 10^-6  mm² /sec) and a 95%-sensitivity cutoff indicating bone marrow edema (<1155 × 10^-6  mm² /sec). Diagnostic accuracy of 95% was achieved for 73% (29/40) of the subjects.

DATA CONCLUSION

DWI with ADC maps distinguishes between healthy and abnormal bone on forefoot MRI. Calculated cutoff values allow confirmation or exclusion of osteomyelitis in a high proportion of subjects.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Systematic review: investigating the added diagnostic value of gadolinium contrast agents for osteomyelitis in the appendicular skeleton

OBJECTIVE

Osteomyelitis is an infection of the bone marrow. MRI with gadolinium-based contrast is frequently performed for cases of suspected osteomyelitis. The objective of this systematic review is to examine the diagnostic accuracy of contrast-enhanced vs non-contrast-enhanced MRI for osteomyelitis in the appendicular skeleton.

MATERIALS AND METHODS

We conducted a systematic review of MRI in the diagnosis of osteomyelitis by searching MEDLINE and EMBASE from January 2000 to March 2020. There were 21 studies that met the inclusion criteria for the systematic review for a total of 1095 patients. Analytic methods were based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Evidence was evaluated using the STARD criteria for evaluation of completeness and transparency of reporting.

RESULTS

For diagnosing osteomyelitis in the appendicular skeleton, MRI with gadolinium-based contrast has 89% sensitivity (95% CI, 86-92%), 79% specificity (95% CI, 75-83%), and 90% overall diagnostic accuracy ([SE] = 0.03). For diagnosing osteomyelitis in the appendicular skeleton, MRI without gadolinium-based contrast has a 92% sensitivity (95% CI, 87-96%), 89% specificity (95% CI, 84-93%), and 96% overall diagnostic accuracy ([SE] = 0.03). The median score of included studies was 85% utilizing the STARD criteria with excellent interobserver agreement of 83.4%. Limitations included small sample size of studies, with retrospective designs.

CONCLUSION

No evidence was found to suggest an added diagnostic value of gadolinium contrast for the diagnosis of osteomyelitis in the appendicular skeleton. For routine cases of suspected non-spinal osteomyelitis, non-contrast MRI of the area of interest is the next most appropriate study after radiographs.

Benefits of diffusion-weighted imaging in pediatric acute osteoarticular infections

BACKGROUND

Contrast-enhanced magnetic resonance imaging (MRI) is recommended for the diagnosis of acute osteoarticular infections in children. Diffusion-weighted imaging (DWI) may be an alternative to the injection of gadolinium.

OBJECTIVE

To evaluate unenhanced MRI with DWI in comparison to contrast-enhanced MRI for the diagnostic work-up of acute osteoarticular infections in children.

MATERIALS AND METHODS

This retrospective study included 36 children (age range: 7 months-12 years) with extra-spinal osteoarticular infections and MRI performed within 24 h of admission. MRI protocol included short tau inversion recovery (STIR), water-only T2 Dixon, T1, DWI, and gadolinium-enhanced T1 sequences. Two readers reviewed three sets of images: 1) unenhanced sequences, 2) unenhanced sequences with DWI and 3) unenhanced followed by contrast-enhanced sequences (reference standard). Sensitivity and specificity of sets 1 and 2 were compared to set 3 and assessed to identify osteoarticular infections: osteomyelitis (long bones, metaphyseal equivalents), septic arthritis and abscess (soft tissues, bone).

RESULTS

All 14 cases of osteomyelitis in the metaphyses and diaphyses of long bones and all 27 cases of septic arthritis were identified by unenhanced sequences, but 4/16 abscesses were missed. For the diagnosis of abscess, DWI increased sensitivity to 100%. Among the 18 osteomyelitis in metaphyseal equivalents, 4 femoral head chondroepiphyses were identified by contrast-enhanced sequences only.

CONCLUSION

MRI for suspected pediatric acute osteoarticular infections is the best diagnostic modality to guide patient management. An unenhanced protocol with DWI may be an alternative to a contrast-based protocol, even in the presence of an abscess. However, gadolinium remains necessary to assess for chondroepiphyseal involvement of the femoral head.

Diffusion-weighted MR imaging of musculoskeletal tissues: incremental role over conventional MR imaging in bone, soft tissue, and nerve lesions

Diffusion-weighted imaging is increasingly becoming popular in musculoskeletal radiology for its incremental role over conventional MR imaging in the diagnostic strategy and assessment of therapeutic response of bone and soft tissue lesions. This article discusses the technical considerations of diffusion-weighted imaging, how to optimize its performance, and outlines the role of this novel imaging in the identification and characterization of musculoskeletal lesions, such as bone and soft tissue tumors, musculoskeletal infections, arthritis, myopathy, and peripheral neuropathy. The readers can use the newly learned concepts from the presented material containing illustrated case examples to enhance their conventional musculoskeletal imaging and interventional practices and optimize patient management, their prognosis, and outcomes.

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.

Pathophysiology and Molecular Imaging of Diabetic Foot Infections

Diabetic foot infection is the leading cause of non-traumatic lower limb amputations worldwide. In addition, diabetes mellitus and sequela of the disease are increasing in prevalence. In 2017, 9.4% of Americans were diagnosed with diabetes mellitus (DM). The growing pervasiveness and financial implications of diabetic foot infection (DFI) indicate an acute need for improved clinical assessment and treatment. Complex pathophysiology and suboptimal specificity of current non-invasive imaging modalities have made diagnosis and treatment response challenging. Current anatomical and molecular clinical imaging strategies have mainly targeted the host's immune responses rather than the unique metabolism of the invading microorganism. Advances in imaging have the potential to reduce the impact of these problems and improve the assessment of DFI, particularly in distinguishing infection of soft tissue alone from osteomyelitis (OM). This review presents a summary of the known pathophysiology of DFI, the molecular basis of current and emerging diagnostic imaging techniques, and the mechanistic links of these imaging techniques to the pathophysiology of diabetic foot infections.

Pathophysiology and Molecular Imaging of Diabetic Foot Infections

Diabetic foot infection is the leading cause of non-traumatic lower limb amputations worldwide. In addition, diabetes mellitus and sequela of the disease are increasing in prevalence. In 2017, 9.4% of Americans were diagnosed with diabetes mellitus (DM). The growing pervasiveness and financial implications of diabetic foot infection (DFI) indicate an acute need for improved clinical assessment and treatment. Complex pathophysiology and suboptimal specificity of current non-invasive imaging modalities have made diagnosis and treatment response challenging. Current anatomical and molecular clinical imaging strategies have mainly targeted the host's immune responses rather than the unique metabolism of the invading microorganism. Advances in imaging have the potential to reduce the impact of these problems and improve the assessment of DFI, particularly in distinguishing infection of soft tissue alone from osteomyelitis (OM). This review presents a summary of the known pathophysiology of DFI, the molecular basis of current and emerging diagnostic imaging techniques, and the mechanistic links of these imaging techniques to the pathophysiology of diabetic foot infections.

3D MRI of the Hand and Wrist: Technical Considerations and Clinical Applications

In the last few years, major developments have been observed in the field of magnetic resonance imaging (MRI). Advances in both scanner hardware and software technologies have witnessed great leaps, enhancing the diagnostic quality and, therefore, the value of MRI. In musculoskeletal radiology, three-dimensional (3D) MRI has become an integral component of the diagnostic pathway at our institutions. This technique is particularly relevant in patients with hand and wrist symptoms, due to the intricate nature of the anatomical structures and the wide range of differential diagnoses for most presentations. We review the benefits of 3D MRI of the hand and wrist, commonly used pulse sequences, clinical applications, limitations, and future directions. We offer guidance for enhancing the image quality and tips for image interpretation of 3D MRI of the hand and wrist.

Multimodality Imaging of Foreign Bodies: New Insights into Old Challenges

Traumatic wounds and lacerations are a common reason for patients to present to emergency departments, with retained foreign bodies (FBs) accounting for 7%-15% of cases, particularly those involving the extremities. These retained materials result in a granulomatous tissue response known as an FB reaction, a pathologic attempt to isolate the FB from the host. The most common FB materials are glass, metal, and wood, but other compositions can also be found, such as plastic and animal-derived materials. Clinical history, physical examination, and wound exploration are essential in investigation of retained material but are not sufficient to exclude an FB, and additional investigation is required. Imaging evaluation is a useful tool to help depict and locate an FB, assess possible complications, and guide removal. Conventional radiography, the first-line method in this scenario, is a widely available low-cost depiction method that has good sensitivity for depicting FBs. If the retained material is not depicted at conventional radiography, US can be performed. US is highly sensitive in depicting both radiolucent and radiopaque FBs in superficial locations. For deeper objects, CT may be necessary. MRI is the best imaging modality to delineate local soft-tissue and osseous complications. Retained FBs can result in early and delayed complications, with infection being the most frequent complication. To avoid preventable morbidities related to FBs, radiologists should be familiar with imaging findings and provide essential information to help the attending physician treat each patient. Online supplemental material is available for this article. ^©RSNA, 2020.

Radiologic Mimics of Osteomyelitis and Septic Arthritis: A Pictorial Essay

Various imaging techniques may be employed in the investigation of suspected bone and joint infections. These include ultrasound, radiography, functional imaging such as positron emission tomography (PET) and nuclear scintigraphy, and cross-sectional imaging, including computed tomography (CT) and magnetic resonance imaging (MRI). The cross-sectional modalities represent the imaging workhorse in routine practice. The role of imaging also extends to include assessment of the anatomical extent of infection, potentially associated complications, and treatment response. The imaging appearances of bone and joint infections are heterogeneous and depend on the duration of infection, an individual patient's immune status, and virulence of culprit organisms. To add to the complexity of radiodiagnosis, one of the pitfalls of imaging musculoskeletal infection is the presence of other conditions that can share overlapping imaging features. This includes osteoarthritis, vasculopathy, inflammatory, and even neoplastic processes. Different pathologies may also coexist, for example, diabetic neuropathy and osteomyelitis. This pictorial review aims to highlight potential mimics of osteomyelitis and septic arthritis that are regularly encountered, with emphasis on specific imaging features that may aid the radiologist and clinician in distinguishing an infective from a noninfective aetiology.

Assessment of bone marrow fat fractions in the mandibular condyle head using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method

The prevalence of temporomandibular joint disorder (TMD) is gradually increasing, and magnetic resonance imaging (MRI) is becoming increasingly common as a modality used to diagnose TMD. Edema and osteonecrosis in the bone marrow of the mandibular condyle have been considered to be precursors of osteoarthritis, but these changes are not evaluated accurately and quantitatively on routine MRI. The iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method, as a cutting-edge MRI technique, can separate fat and water using three asymmetric echo times and the three-point Dixon method. The purpose of this study was to analyze the quantitative fat fraction (FF) in the mandibular condyle head using the IDEAL-IQ method. Seventy-nine people who underwent MRI using IDEAL-IQ were investigated and divided into 1) the control group, without TMD symptoms, and 2) the TMD group, with unilateral temporomandibular joint (TMJ) pain. In both groups, the FF of the condyle head in the TMJ was analyzed by two oral and maxillofacial radiologists. In the TMD group, 29 people underwent cone-beam computed tomography (CBCT) and the presence or absence of bony changes in the condylar head was evaluated. The FF measurements of the condyle head using IDEAL-IQ showed excellent inter-observer and intra-observer agreement. The average FF of the TMD group was significantly lower than that of the control group (p < 0.05). In the TMD group, the average FF values of joints with pain and joints with bony changes were significantly lower than those of joints without pain or bony changes, respectively (p < 0.05). The FF using IDEAL-IQ in the TMJ can be helpful for the quantitative diagnosis of TMD.

The "Balgrist Score" for evaluation of Charcot foot: a predictive value for duration of off-loading treatment

OBJECTIVE

To develop a new magnetic resonance imaging(MRI) scoring system for evaluation of active Charcot foot and to correlate the score with a duration of off-loading treatment ≥ 90 days.

METHODS

An outpatient clinic database was searched retrospectively for MRIs of patients with active Charcot foot who completed off-loading treatment. Images were assessed by two radiologists (readers 1 and 2) and an orthopedic surgeon (reader 3). Sanders/Frykberg regions I-V were evaluated for soft tissue edema, bone marrow edema, erosions, subchondral cysts, joint destruction, fractures, and overall regional manifestation using a score according to degree of severity (0-3 points). Intraclass correlations (ICC) for interreader agreement and receiver operating characteristic analysis between MR findings and duration of off-loading-treatment were calculated.

RESULTS

Sixty-five feet in 56 patients (34 men) with a mean age of 62.4 years (range: 44.5-85.5) were included. Region III (reader 1/reader 2: 93.6/90.8%) and region II (92.3/90.8%) were most affected. The most common findings in all regions were soft tissue edema and bone marrow edema. Mean time between MRI and cessation of off-loading-treatment was 150 days (range: 21-405). The Balgrist Score was defined in regions II and III using soft tissue edema, bone marrow edema, joint destruction, and fracture. Interreader agreement for Balgrist Score was excellent: readers 1/2: ICC 0.968 (95% CI: 0.948, 0.980); readers 1/2/3: ICC 0.856 (0.742, 0.917). A cutoff of ≥ 9.0 points in Balgrist Score (specificity 72%, sensitivity 66%) indicated a duration of off-loading treatment ≥ 90 days.

CONCLUSION

The Balgrist Score is a new MR scoring system for assessment of active Charcot foot with excellent interreader agreement. The Balgrist Score can help to identify patients with off-loading treatment ≥ 90 days.

Comparison of the diagnostic accuracy of diffusion-weighted and dynamic contrast-enhanced MRI with 18F-FDG PET/CT to differentiate osteomyelitis from Charcot neuro-osteoarthropathy in diabetic foot

PURPOSE

To compare the diagnostic accuracy of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) involving two region of interest (ROI) sizes with 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) to differentiate diabetic foot osteomyelitis (DFO) from Charcot neuro-osteoarthropathy (CN).

METHOD

Thirty-one diabetic patients were included in this prospective study. Two readers independently evaluated DWI (apparent diffusion coefficient [ADC] and high-b-value signal pathological-to-normal bone ratio [DWIr]) and DCE-MRI parameters (K^trans, K_ep, V_e, internal area under the gadolinium curve at 60 s [iAUC₆₀] and time intensity curve [TIC]) using two different ROI sizes, and ¹⁸F-FDG PET/CT parameters (visual assessment, SUV_max, delayed SUV_max, and percentage changes between SUV_max and delayed SUV_max). Techniques were compared by univariate analysis using the area under the receiver operating characteristic curve [AUC]. Reliability was analyzed with Kappa and Intraclass correlation [ICC].

RESULTS

DWIr, K^trans and iAUC₆₀ showed better diagnostic accuracy (AUC = 0.814-0.830) and reliability (ICC > 0.9) for large than for small ROIs (AUC = 0.736-0.750; ICC = 0.6 in K^trans, 0.8 in DWIr and iAUC₆₀). TIC showed moderate diagnostic performance (AUC = 0.739-0.761) and reliability (κ 0.7). Visual assessment of ¹⁸F-FDG PET/CT demonstrated a significantly higher accuracy (AUC = 0.924) than MRI parameters. Semi-quantitative ¹⁸F-FDG PET/CT parameters did not provide significant improvement over visual analysis (AUC = 0.848-0.903).

CONCLUSION

DWIr, K^trans and iAUC₆₀ allowed reliable differentiation of DFO and CN, particularly for large ROIs. Visual assessment of ¹⁸F-FDG PET/CT was the most accurate technique for differentiation.

Diabetic Foot Infections: The Diagnostic Challenges

Diabetic foot infections (DFIs) are severe complications of long-standing diabetes, and they represent a diagnostic challenge, since the differentiation between osteomyelitis (OM), soft tissue infection (STI), and Charcot’s osteoarthropathy is very difficult to achieve. Nevertheless, such differential diagnosis is mandatory in order to plan the most appropriate treatment for the patient. The isolation of the pathogen from bone or soft tissues is still the gold standard for diagnosis; however, it would be desirable to have a non-invasive test that is able to detect, localize, and evaluate the extent of the infection with high accuracy. A multidisciplinary approach is the key for the correct management of diabetic patients dealing with infective complications, but at the moment, no definite diagnostic flow charts still exist. This review aims at providing an overview on multimodality imaging for the diagnosis of DFI and to address evidence-based answers to the clinicians when they appeal to radiologists or nuclear medicine (NM) physicians for studying their patients.

Adult Acquired Flatfoot Deformity: Anatomy, Biomechanics, Staging, and Imaging Findings

Adult acquired flatfoot deformity (AAFD) is a common disorder that typically affects middle-aged and elderly women, resulting in foot pain, malalignment, and loss of function. The disorder is initiated most commonly by degeneration of the posterior tibialis tendon (PTT), which normally functions to maintain the talonavicular joint at the apex of the three arches of the foot. PTT degeneration encompasses tenosynovitis, tendinosis, tendon elongation, and tendon tearing. The malaligned foot is initially flexible but becomes rigid and constant as the disorder progresses. Tendon dysfunction commonly leads to secondary damage of the spring ligament and talocalcaneal ligaments and may be associated with injury to the deltoid ligament, plantar fascia, and other soft-tissue structures. Failure of multiple stabilizers appears to be necessary for development of the characteristic planovalgus deformity of AAFD, with a depressed plantar-flexed talus bone, hindfoot and/or midfoot valgus, and an everted flattened forefoot. AAFD also leads to gait dysfunction as the foot is unable to change shape and function adequately to accommodate the various phases of gait, which require multiple rapid transitions in foot position and tone for effective ambulation. The four-tier staging system for AAFD emphasizes physical examination findings and metrics of foot malalignment. Mild disease is managed conservatively, but surgical procedures directed at the soft tissues and/or bones become necessary and progressively more invasive as the disease progresses. Although much has been written about the imaging findings of AAFD, this article emphasizes the anatomy and function of the foot's stabilizing structures to help the radiologist better understand this disabling disorder. Online supplemental material is available for this article. ^©RSNA, 2019.

The amputation and survival of patients with diabetic foot based on establishment of prediction model

OBJECTIVE

The objective of this paper is to study the establishment of predictive models and the amputation and survival of patients with diabetic foot.

METHODS

A total of 200 inpatients with diabetic foot were selected as the research subject in this study. The amputation and survival status of diabetic foot patients were followed up by telephone. The relevant indicators were screened by cluster analysis. The predictive model was established respectively based on proportional hazard regression analysis, back propagation neural network (BPNN) and BPNN based on genetic algorithm optimization, and the reliability of the three prediction models (PM) was evaluated and compared.

RESULTS

The risk factors for amputation were severe ulcer disease, glycosylated hemoglobin and low-density lipoprotein cholesterol. The risk factors for death were cerebrovascular disease, severe ulcer disease and peripheral arterial disease. In case that the outcome was amputation, the PM of BPNN and the PM of BPNN based on genetic algorithm optimization have obviously higher AUC (area under the receiver operating characteristic curve) than the PM of proportional hazard regression analysis, and the difference was statistically significant (P < 0.05). Among the three PMs, the PM based on BPNN had the highest AUC, sensitivity and specificity (SAS). In case that the outcome was death, the PM of BPNN and the PM of BPNN based on genetic algorithm optimization had almost the same AUC, and were obviously higher than the PM based on proportional hazard regression analysis. The difference was statistically significant (P < 0.05). The PM based on BPNN and the BPNN based on genetic algorithm optimization had higher SAS than the PM based on COX regression analysis.

CONCLUSION

The PM of BPNN and BPNN based on genetic algorithm optimization have better prediction effect than the PM based on proportional hazard regression analysis. It can be used for amputation and survival analysis of diabetic foot patients.

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis and treatment of foot infection in persons with diabetes and updates the 2015 IWGDF infection guideline. On the basis of patient, intervention, comparison, outcomes (PICOs) developed by the infection committee, in conjunction with internal and external reviewers and consultants, and on systematic reviews the committee conducted on the diagnosis of infection (new) and treatment of infection (updated from 2015), we offer 27 recommendations. These cover various aspects of diagnosing soft tissue and bone infection, including the classification scheme for diagnosing infection and its severity. Of note, we have updated this scheme for the first time since we developed it 15 years ago. We also review the microbiology of diabetic foot infections, including how to collect samples and to process them to identify causative pathogens. Finally, we discuss the approach to treating diabetic foot infections, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and for bone infections, when and how to approach surgical treatment, and which adjunctive treatments we think are or are not useful for the infectious aspects of diabetic foot problems. For this version of the guideline, we also updated four tables and one figure from the 2016 guideline. We think that following the principles of diagnosing and treating diabetic foot infections outlined in this guideline can help clinicians to provide better care for these patients.

Dual energy CT and research of the bone marrow edema: Comparison with MRI imaging

Aims

To evaluate the diagnostic accuracy of the Dual Energy Computed Tomography (DECT) in the research of the bone marrow edema.

Methods and Material

The MRI images of 100 patients with episodes of articular and or bone pains with or without traumatic lesion were prospectively evaluated during a period between March 2018 and February 2019. In the presence of bone marrow edema, a DECT was performed. The measurement of the density of the bone marrow edema in the DECT was compared with healthy bone in the same patient by two operators.

Result

The DECT and MRI images of 15 patients with bone marrow edema were compared. The mean of pathologic bone marrow edema was 1008.20 (Standard Deviation (SD) 23.00), for healthy bone marrow 947.53 (SD 16.42), and t = 11.75, with a statistical significance P < 0.05 (Statistical significance 95%). The agreement between the measurements of the two radiologists has a statistical significance (P < 0.05).

Conclusion

The DECT presents an excellent diagnostic accuracy to detect the bone marrow edema, comparable to MRI. The utility of these recent possibilities is maximum where access to MRI is still very difficult.

[Rheumatoid arthritis-mimics : When appearances are deceptive]

Rheumatology represents a discipline full of differential diagnoses. Even for classical diseases, such as rheumatoid arthritis as the most frequent chronic inflammatory joint disease and described so clearly in many textbooks, it is not uncommon that it can be a diagnostic challenge in daily practice. This applies to arthritic joint involvement and also to frequently associated extra-articular manifestations. The patient history and results of the clinical examination are essential; however, laboratory and imaging findings often make a significant contribution to confirming the diagnosis, especially in early phases of the disease. This article, which makes no claims to completeness, focuses on diseases that in the opinion of the authors can imitate rheumatoid arthritis due to similar joint and other organ manifestations. These include metabolic, inflammatory infective and non-infective as well as tumorous diseases. A misinterpretation as rheumatoid arthritis as a rule leads to long-term and severe consequences for affected patients. Thus, the diagnosis of rheumatoid arthritis should be questioned and re-evaluated in cases of unusual accompanying symptoms, atypical course of disease and a lack of response to standard treatment approaches.

The Charcot foot: a pictorial review

Charcot foot refers to an inflammatory pedal disease based on polyneuropathy; the detailed pathomechanism of the disease is still unclear. Since the most common cause of polyneuropathy in industrialized countries is diabetes mellitus, the prevalence in this risk group is very high, up to 35%. Patients with Charcot foot typically present in their fifties or sixties and most of them have had diabetes mellitus for at least 10 years. If left untreated, the disease leads to massive foot deformation. This review discusses the typical course of Charcot foot disease including radiographic and MR imaging findings for diagnosis, treatment, and detection of complications.

The many facets of neuropathic arthropathy

Neuropathic arthropathy, also known as Charcot arthropathy, refers to progressive and occasionally rapid joint destruction that results from underlying disorders of the nervous system. This pictorial essay aims to illustrate various radiologic findings in neuropathic arthropathy using various examples in the upper and lower limbs and in the spine. Pearls for radiologic diagnosis, clinical differential considerations and possible complications are discussed individually for each joint. MR imaging techniques for differentiating infection and neuropathic arthropathy are explained with examples. Management issues are outlined.

Added value of MRI to X-ray in guiding the extent of surgical resection in diabetic forefoot osteomyelitis: a review of pathologically proven, surgically treated cases

OBJECTIVE

This study retrospectively evaluated the added value of MRI over X-ray in guiding the extent of amputation in a cohort of patients with surgically treated, pathologically proven osteomyelitis.

MATERIALS AND METHODS

A database search revealed 32 cases of pathology-proven diabetic forefoot osteomyelitis between 2006 and 2016, in which X-ray, MRI, and surgery occurred within 30 days. Data collection included extent of osteomyelitis reported on imaging and extent of subsequent amputation using a point system. Added value of MRI over X-ray in guiding surgical resection was stated if the X-ray was negative, MRI was positive, and there was MRI-surgical concordance; if both modalities were positive, X-ray was discordant whereas the MRI was concordant; or if MRI detected an abscess. Two-tailed Fisher's exact test compared proportions.

RESULTS

In 9 cases that were positive on both modalities, MRI identified an average of 1.2 additional bone segments of disease. There was surgical agreement with X-ray in 3 out of 31 cases (9.7%, 95%CI 0-20.1) and with MRI in 17 out of 31 cases (55%, 37.3-72.4; p < 0.0001). There was an added value of MRI over X-ray in guiding surgical treatment in 64.5% of cases (95% CI 47.7%-81.4%). MRI added value in 5 out of 9 X-rays positive for osteomyelitis and in 15 out of 22 negative (p value was not significant).

CONCLUSION

Magnetic resonance imaging demonstrated added value over X-ray in guiding surgical management in both X-ray-negative and -positive cases. Although multiple factors are involved in determining the degree of surgical excision, MRI is a clinically useful component of the diagnostic algorithm in patients who undergo surgical treatment.

Radiographic Musculoskeletal Findings Indicating Opioid Misuse: An Overview for Orthopedic Surgeons

BACKGROUND

Given the high prevalence of musculoskeletal conditions in the USA, it is important for orthopedic surgeons to promptly identify patients who may be at risk for opioid misuse.

QUESTIONS/PURPOSES

The aim of this literature review was to elucidate various musculoskeletal pathologies and complications, as seen on imaging, that may indicate opioid misuse or opioid use disorder.

METHODS

A literature search was conducted using the PubMed, Scopus, and Cochrane Library databases for articles related to imaging findings associated with chronic opioid use or misuse in orthopedic patients. Two independent reviewers conducted the search utilizing pertinent Boolean operations.

RESULTS

We reviewed 36 full-text articles and categorized the radiographic evidence of opioid misuse as follows: soft-tissue radiologic findings, cellulitis, necrotizing fasciitis, abscess formation, retained needles, discitis, myopathy and rhabdomyolysis, osteomyelitis, septic arthritis, and septic thrombophlebitis.

CONCLUSION

Knowledge of the radiologic findings of opioid misuse will assist orthopedic surgeons in making timely diagnoses that may alter therapeutic regimens for their patients.

Dynamic contrast-enhanced magnetic resonance imaging for differentiating osteomyelitis from acute neuropathic arthropathy in the complicated diabetic foot

OBJECTIVE

The main purpose of this study was to investigate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating osteomyelitis from acute neuropathic arthropathy in the diabetic foot.

MATERIALS AND METHODS

This prospective study was carried out on 30 diabetic foot patients, with a mean age of 51 years. The patients all underwent clinical examinations, laboratory examinations and DCE-MRI. The DCE-MRI parameters (K^trans, K_ep and V_e) of the regions of acute neuropathic arthropathy and osteomyelitis were calculated. Receiver operating characteristic curves (ROCs) were used to identify the DCE-MRI parameters that showed the highest accuracy in differentiating the acute neuropathic arthropathy from the osteomyelitic regions. Pearson correlation coefficients were used to assess the correlations among the DCE-MRI parameters, the level of C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR).

RESULTS

The K^trans, K_ep and V_e values of the osteomyelitic regions were higher than those of the acute neuropathic arthropathy regions, and significant differences were found between the two groups (P = 0.000, P = 0.000, P = 0.000). The ROC analysis showed that K^trans and V_e performed best in differentiating osteomyelitis from acute neuropathic arthropathy, both with an area under the curve of 0.938. The Pearson correlation coefficients showed that the DCE-MRI parameters correlated significantly with the level of CRP and ESR (P = 0.000, P = 0.014, P = 0.000; P = 0.000, P = 0.000, P = 0.013).

CONCLUSIONS

Our results showed that DCE-MRI may provide reproducible parameters that can reliably differentiate osteomyelitis from acute neuropathic arthropathy.

MR Imaging of Joint Infection and Inflammation with Emphasis on Dynamic Contrast-Enhanced MR Imaging

Contrast-enhanced MR imaging (CE-MR imaging) is recommended for diagnosis and monitoring of infectious and most inflammatory joint diseases. CE-MR imaging clearly differentiates soft and bony tissue from fluid collections and infectious debris. To improve imaging information, a dynamic CE-MR imaging sequence (DCE-MR imaging) sequence can be applied using fast T1-weighted sequential image acquisition during contrast injection. Use of DCE-MR imaging allows robust extraction of quantitative information regarding blood flow and capillary permeability, especially when dedicated analysis methods and software are used to analyze contrast kinetics. This article describes principles of DCE-MR imaging for the assessment of infectious and inflammatory joint diseases.

New trends in the orthopaedic management of diabetic foot

Although there are various types of therapeutic footwear currently used to treat diabetic foot ulcers (DFUs), recent literature has enforced the concept that total-contact casts are the benchmark.Besides conventional clinical tests and imaging modalities, advanced MRI techniques and high-sensitivity nuclear medicine modalities present several advantages for the investigation of diabetic foot problems.The currently accepted principles of DFU care are rigorous debridement followed by modern wound dressings to provide a moist wound environment. Recently, hyperbaric oxygen and negative pressure wound therapy have aroused increasing attention as an adjunctive treatment for patients with DFUs.For DFU, various surgical treatments are currently available, including resection arthroplasty, metatarsal osteotomies and metatarsal head resections.In the modern management of the Charcot foot, surgery in the acute phase remains controversial and under investigation. While conventional fixation techniques are frequently insufficient to keep alignment postoperatively, superconstruct techniques could provide a successful fixation.Retrograde intramedullary nailing has been a generally accepted method of achieving stability. The midfoot fusion bolt is a current treatment device that maintains the longitudinal columns of the foot. Also, Achilles tendon lengthening remains a popular method in the management of Charcot foot. Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170073.