Imaging of Musculoskeletal Soft-Tissue Infections in Clinical Practice: A Comprehensive Updated Review

Comparison between ZOOMit DWI and conventional DWI in the assessment of foot and ankle infection: a prospective study

OBJECTIVE

The study aimed to compare ZOOMit diffusion-weighted imaging (DWI) MRI with conventional DWI MRI for visualizing small bones in the foot, soft tissue abscesses, and osteomyelitis.

MATERIALS AND METHODS

The cohort consisted of a consecutive series of patients with potential foot and ankle infections referred for MR imaging. Patients were imaged using both conventional and ZOOMit DWI in the same setting. Blinded reads were then conducted in separate settings and independent of known clinical diagnosis by two expert radiologists. The results from the reads were compared statistically using paired t-tests and with biopsy specimen analysis, both anatomopathological and microbiological.

RESULTS

There was improvement in fat suppression using ZOOMit sequence compared to conventional DWI (p = .001) with no significant difference in motion artifacts (p = .278). ZOOMit had a higher rate of concordance with pathology findings for osteomyelitis (72%, 31/43 cases) compared with conventional DWI (60%, 26/43 cases). ZOOMit also identified 46 additional small bones of the foot and ankle (405/596, 68.0%) than conventional DWI (359/596, 60.2%). Conventional DWI however exhibited a more negative contrast-to-noise ratio (CNR) than ZOOMit (p = 0.001).

CONCLUSION

ZOOMit DWI improves distal extremity proton diffusion assessment and helps visualize more bones in the foot, with less image distortion and improved fat saturation at the expense of reduced CNR. This makes it a viable option for assessing lower extremity infections.

CLINICAL RELEVANCE STATEMENT

This study highlights the novel utilization of ZOOMit diffusion-weighted imaging (DWI) for the assessment of lower extremity lesions compared to conventional DWI.

KEY POINTS

• Distal extremity diffusion-weighted imaging (DWI) is often limited. • ZOOMit DWI displayed improved fat suppression with less motion artifacts and better visualization of the lower extremity bones than conventional DWI. • ZOOMit shows decreased contrast-to-noise ratio than conventional DWI.

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.

Lower extremity infections: Essential anatomy and multimodality imaging findings

In modern practice, imaging plays an integral role in the diagnosis, evaluation of extent, and treatment planning for lower extremity infections. This review will illustrate the relevant compartment anatomy of the lower extremities and highlight the role of plain radiographs, CT, US, MRI, and nuclear medicine in the diagnostic workup. The imaging features of cellulitis, abscess and phlegmon, necrotizing soft tissue infection, pyomyositis, infectious tenosynovitis, septic arthritis, and osteomyelitis are reviewed. Differentiating features from noninfectious causes of swelling and edema are discussed.

Imaging features for the evaluation of skin and nail infections

Clinical manifestations of dermatological and musculoskeletal conditions can sometimes overlap, leading to confusion in diagnosis. Patients with nail and skin infections may undergo imaging examinations with suspicions of muscle, tendon, or joint injuries. Dermatological infections often involve soft tissues and musculoskeletal structures, and their etiology can range from fungi, bacteria, viruses, to protozoa. Relying solely on physical examination may not be sufficient for accurate diagnosis and treatment planning, necessitating the use of complementary imaging exams. The objective of this paper is to present and discuss imaging findings of the main infectious conditions affecting the nail apparatus and skin. The paper also highlights the importance of imaging in clarifying diagnostic uncertainties and guiding appropriate treatment for dermatological conditions.

Early diagnosis of necrotizing fasciitis: Imaging techniques and their combined application

Necrotizing fasciitis is a clinical, surgical emergency characterized by an insidious onset, rapid progression, and a high mortality rate. The disease's mortality rate has remained high for many years, mainly because of its atypical clinical presentation, which prevents many cases from being diagnosed early and accurately, resulting in patients who may die from uncontrollable septic shock and multi-organ failure. But unfortunately, no diagnostic indicator can provide a certain early diagnosis of NF, and clinical judgement of NF is still based on the results of various ancillary tests combined with the patient's medical history, clinical manifestations, and the physician's experience. This review provides a brief overview of the epidemiological features of NF and then discusses the most important laboratory indicators and scoring systems currently employed to diagnose NF. Finally, the latest progress of several imaging techniques in the early diagnosis of NF and their combined application with other diagnostic indices are highlighted. We point out promising research directions based on an objective evaluation of the advantages and shortcomings of different methods, which provide a basis for further improving the early diagnosis of NF.

Imaging of MSK infections in the ER

Musculoskeletal infections in the ER are not an uncommon presentation. The clinical context is critical in determining the suspicion for infection and degree of tissue involvement which can involve all layers from the skin to bones. The location, extent, and severity of clinically suspected infection directly relate to the type of imaging performed. Uncomplicated cellulitis typically does not require any imaging. Localized and superficial infections can mostly be evaluated with ultrasound. If there is a diffuse site (an entire extremity) or suspected deeper involvement (muscle/deep fascia), then CT is accurate in diagnosing, widely available, and performed quickly. With potential osseous involvement, MRI is the gold standard for diagnosing acute osteomyelitis; however, it has the drawbacks of longer scan times, artifacts including patient motion, and limited availability.

The Usefulness of Magnetic Resonance Imaging in the Management of Acute Phlegmonous Esophagitis

Acute phlegmonous esophagitis is a rare life-threatening disease that often requires surgical intervention in case of complications, including esophageal abscess, perforation, or mediastinitis. We present a case of acute phlegmonous esophagitis, in which magnetic resonance imaging (MRI) proved useful in planning the treatment strategy. An 89-year-old woman was admitted to the emergency department with painful swallowing and respiratory distress. She was diagnosed with acute phlegmonous esophagitis and a hypopharyngeal abscess based on computed tomography (CT) findings. However, there was a discrepancy between the clinical course and CT findings. Given the improvement of the patient's condition with conservative treatment with ampicillin/sulbactam, the CT findings suggested an apparent abscess due to increased esophageal wall thickness. However, MR diffusion-weighted images showed a slightly high-intensity signal, suggesting that the enlargement was due to edema rather than an abscess. The patient recovered successfully following conservative treatment. Thus, our findings demonstrate the utility of MRI in the treatment planning of acute phlegmonous esophagitis, especially in cases with unreliable contrast-enhanced CT findings. However, future studies are warranted to explore the utility of MRI in the management of such cases.

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.

Phytoconstituent-Loaded Nanofibrous Meshes as Wound Dressings: A Concise Review

In the past, wounds were treated with natural materials, but modern wound dressings include functional elements to expedite the process of healing and to improve skin recovery. Due to their exceptional properties, nanofibrous wound dressings are now the most cutting-edge and desirable option. Similar in structure to the skin’s own extracellular matrix (ECM), these dressings can promote tissue regeneration, wound fluid transportation, and air ductility for cellular proliferation and regeneration owing to their nanostructured fibrous meshes or scaffolds. Many academic search engines and databases, such as Google Scholar, PubMed, and Sciencedirect, were used to conduct a comprehensive evaluation of the literature for the purposes of this investigation. Using the term “nanofibrous meshes” as a keyword, this paper focuses on the importance of phytoconstituents. This review article summarizes the most recent developments and conclusions from studies on bioactive nanofibrous wound dressings infused with medicinal plants. Several wound-healing methods, wound-dressing materials, and wound-healing components derived from medicinal plants were also discussed.

Soft Tissue Masses of the Hand: A Review of Clinical Presentation and Imaging Features

More than 15% of all soft-tissue tumors arise in the hand. Because of the location of these tumors, even small abnormalities may be alarming to patients on presentation. Although the majority of lesions are benign and can be diagnosed solely by history and physical examination, additional imaging workup may be required to confirm a diagnosis or define anatomic extent of involvement. This paper aims to review the basic epidemiology, clinical presentation, imaging findings, and treatment options of the more common soft-tissue tumors of the hand.