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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., (© 2024. The Author(s).)

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., (© 2024. The Author(s).)

Background: Skin and soft tissue infections (SSTIs) are commonly encountered in clinical practice. Point-of-care ultrasound (POCUS) is becoming an increasingly valuable tool in hospital medicine, especially with advancements in ultrasound technology that make it easier to perform. POCUS can augment the history and physical exam in patients with suspected SSTIs. POCUS can detect deeper infections, such as abscesses, and expedite time to surgical debridement for life-threatening infections such as necrotizing fasciitis (NF)., Objectives: This review provides an introduction on how to perform and interpret a skin and soft tissue POCUS exam, the key sonographic findings for SSTIs, and how to incorporate these findings into clinical reasoning and management., Methods: SSTI POCUS literature was reviewed using PubMed. All relevant studies with a defined protocol and reported sensitivity and specificity pertaining to the use of POCUS to diagnose SSTIs in adults were included. The authors provide additional input based on their ultrasound expertise and clinical experience., Results: A total of seven studies met the criteria to be included in this review., Conclusions: Soft tissue POCUS is a valuable tool for hospitalists to improve diagnostic accuracy and patient care when assessing suspected SSTIs. Access to equipment, POCUS training, and experience are barriers to widespread use. However, performing a soft tissue POCUS exam is straightforward. It requires less training compared to other POCUS exams, and it has notable potential for routine future practice in the evaluation and management of suspected SSTIs and other dermatologic conditions., (© 2024 Society of Hospital Medicine.)

Skin and soft tissues are among the most common sites of infections. Infections can involve the superficial epidermis to deep muscles and bones. Most infections spread through contiguous structures, although hematogenous spread can occur in the setting of an immunocompromised state and with atypical infections. While clinical diagnosis of infections is possible, it often lacks specificity, necessitating the use of imaging for confirmation. Cross-sectional imaging with US, CT, and MRI is frequently performed not just for diagnosis, but to delineate the extent of infection and to aid in management. Nonetheless, the imaging features have considerable overlap, and as such, it is essential to integrate imaging features with clinical features for managing soft tissue infections. Radiologists must be aware of the imaging features of different infections and their mimics, as well as the pros and cons of each imaging technique to properly use them for appropriate clinical situations. In this review, we summarize the most recent evidence-based features of key soft tissue infections., (© 2024. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

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., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Bedside point-of-care ultrasound (POCUS) has a high utility in clinical settings for scanning soft tissue-related conditions such as skin and soft tissue infections, identifying abscesses or necrotizing soft tissue infections, localization and extraction of embedded foreign bodies, and assessing hospitalized patients for sarcopenia. Regular use of POCUS in patients with soft tissue conditions can improve clinical efficiency and care., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: To demonstrate the usefulness of ultrasonography for differentiating soft tissue infections with or without osteomyelitis in pediatric patients who underwent ultrasonography and subsequent magnetic resonance imaging (MRI)., Methods: Twenty-three patients were classified into 2 groups: 12 patients with and 11 patients without osteomyelitis based on MRI. Osteomyelitis using ultrasound is characterized by the presence of bone cortex irregularity and/or subperiosteal abscess formation. The diagnostic performance of ultrasonography for detecting osteomyelitis and subperiosteal abscess formation was compared with that of MRI. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated with 95% confidence intervals (CIs)., Results: Of 12 osteomyelitis cases, 11 had abnormal bone marrow enhancement (one residual case did not undergo contrast enhancement study) and 5 had subperiosteal abscesses. The diagnostic accuracy of ultrasonography for osteomyelitis was 82.6% (number of correct diagnosis of osteomyelitis/total number = 19/23; 95% CI, 61.2-95.0) and for detecting periosteal abscess was 95.7% (number of correct diagnosis of periosteal abscess/total number = 22/23; 95% CI, 78.1-99.9), respectively. The sensitivity and specificity of ultrasonography for detecting osteomyelitis were 66.7% (95% CI, 34.9-90.1) and 100% (95% CI, 71.5-100), respectively. The sensitivity and specificity of ultrasonography for detecting periosteal abscess were 80% (95% CI, 28.4-99.5), and 100% (95% CI, 81.5-100), respectively. One-third of osteomyelitis cases could not be detected using ultrasonography., Conclusions: Ultrasonography may be useful for diagnosing osteomyelitis in pediatric patients; however, the technique appears limited by low sensitivity. However, it is more accurate for diagnosis of periosteal abscess in these patients., (© 2024 American Institute of Ultrasound in Medicine.)

Purpose: To assess the diagnostic contribution of different imaging studies to diagnose necrotizing soft tissue infections (NSTIs) and the time to surgery in relation to imaging with the hypothesis that imaging studies may lead to significant delays without being able to sufficiently dismiss or confirm the diagnosis since a NSTI is a surgical diagnosis., Methods: A retrospective multicenter cohort study of all NSTI patients between 2010 and 2020 was conducted. The primary outcome was the number of cases in which imaging contributed to or led to change in treatment. The secondary outcomes were time to treatment determined by the time from presentation to surgery and patient outcomes (amputation, intensive care unit (ICU) admission, length of ICU stay, hospital stay, and mortality)., Results: A total of 181 eligible NSTI patients were included. The overall mortality was 21% (n = 38). Ninety-eight patients (53%) received imaging in the diagnostic workup. In patients with a clinical suspicion of a NSTI, 81% (n = 85) went directly to the operating room and 19% (n = 20) underwent imaging before surgery; imaging was contributing in only 15% (n = 3) by ruling out or determining underlying causes. In patients without a clinical suspicion of a NSTI, the diagnosis of NSTI was considered in 35% and only after imaging was obtained., Conclusion: In patients with clinically evident NSTIs, there is no role for standard imaging workup unless it is used to examine underlying diseases (e.g., diverticulitis, pancreatitis). In atypical presenting NSTIs, CT or MRI scans provided the most useful information. To prevent unnecessary imaging and radiation and not delay treatment, the decision to perform imaging studies in patients with a clinical suspicion of a NSTI must be made extremely careful., (© 2024. The Author(s).)

Significance: Necrotizing soft-tissue infections (NSTIs) are life-threatening infections with a cumulative case fatality rate of 21%. The initial presentation of an NSTI is non-specific, frequently leading to misdiagnosis and delays in care. No current strategies yield an accurate, real-time diagnosis of an NSTI., Aim: A first-in-kind, observational, clinical pilot study tested the hypothesis that measurable fluorescence signal voids occur in NSTI-affected tissues following intravenous administration and imaging of perfusion-based indocyanine green (ICG) fluorescence. This hypothesis is based on the established knowledge that NSTI is associated with local microvascular thrombosis., Approach: Adult patients presenting to the Emergency Department of a tertiary care medical center at high risk for NSTI were prospectively enrolled and imaged with a commercial fluorescence imager. Single-frame fluorescence snapshot and first-pass perfusion kinetic parameters-ingress slope (IS), time-to-peak (TTP) intensity, and maximum fluorescence intensity (IMAX)-were quantified using a dynamic contrast-enhanced fluorescence imaging technique. Clinical variables (comorbidities, blood laboratory values), fluorescence parameters, and fluorescence signal-to-background ratios (SBRs) were compared to final infection diagnosis., Results: Fourteen patients were enrolled and imaged (six NSTI, six cellulitis, one diabetes mellitus-associated gangrene, and one osteomyelitis). Clinical variables demonstrated no statistically significant differences between NSTI and non-NSTI patient groups ( p -value ≥ 0.22 ). All NSTI cases exhibited prominent fluorescence signal voids in affected tissues, including tissue features not visible to the naked eye. All cellulitis cases exhibited a hyperemic response with increased fluorescence and no distinct signal voids. Median lesion-to-background tissue SBRs based on snapshot, IS, TTP, and IMAX parameter maps ranged from 3.2 to 9.1, 2.2 to 33.8, 1.0 to 7.5, and 1.5 to 12.7, respectively, for the NSTI patient group. All fluorescence parameters except TTP demonstrated statistically significant differences between NSTI and cellulitis patient groups ( p -value < 0.05 )., Conclusions: Real-time, accurate discrimination of NSTIs compared with non-necrotizing infections may be possible with perfusion-based ICG fluorescence imaging., (© 2024 The Authors.)

There are multiple opportunities for the use of ultrasonography in the diagnosis of skin and soft tissue differentials. Ultrasonography is inexpensive, easily reproducible, and able to provide real-time data in situations where condition changes and progression are common. Not only does bedside ultrasonography provide the clinician an in-depth look beyond epidermal structures into body cavities, it remains a safe, nonionizing radiating, effective, cost-efficient, reliable, and accessible tool for the emergency management of life- and limb-threatening integumentary infections. Unnecessary invasive procedures are minimized, providing improved patient outcomes. Integumentary abnormalities secondary to trauma, surgery, and hospitalization are common among critical care patients. This article provides a brief overview and evidence-based recommendations for the use of ultrasonography in the critical care setting for integumentary system conditions, including common skin and soft tissue differentials, foreign bodies, and burn depth assessment., (©2023 American Association of Critical-Care Nurses.)

Emphysematous osteomyelitis (EO) is a rare condition identified through the presence of intraosseous gas. It is frequently fatal even with prompt recognition and management. We report a case of EO presenting with a necrotizing soft tissue infection of the thigh in the setting of prior pelvic radiation. The purpose of this study was to highlight the unusual association between EO and necrotizing soft tissue infection., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Orthopaedic Surgeons.)

Soft tissue necrosis can occur at different tissue levels, with numerous underlying causes. In this pictorial review, we highlight myonecrosis, and its accompanying stages, fat necrosis, devitalized soft tissue seen with infection, and necrotizing soft tissue infections. Imaging examples are provided with each entity., (© 2023. The Author(s), under exclusive licence to American Society of Emergency Radiology (ASER).)

Objective: Skin and soft tissue infections (SSTI) are commonly diagnosed in the emergency department (ED). While most SSTI are diagnosed with patient history and physical exam alone, ED clinicians may order CT imaging when they suspect more serious or complicated infections. Patients who inject drugs are thought to be at higher risk for complications from SSTI and may undergo CT imaging more frequently. The objective of this study is to characterize CT utilization when evaluating for SSTI in ED patients particularly in patients with intravenous drug use (IVDU), the frequency of significant and actionable findings from CT imaging, and its impact on subsequent management and ED operations., Methods: We performed a retrospective analysis of encounters involving a diagnosis of SSTI in seven EDs across an integrated health system between October 2019 and October 2021. Descriptive statistics were used to assess overall trends, compare CT utilization frequencies, actionable imaging findings, and surgical intervention between patients who inject drugs and those who do not. Multivariable logistic regression was used to analyze patient factors associated with higher likelihood of CT imaging., Results: There were 4833 ED encounters with an ICD-10 diagnosis of SSTI during the study period, of which 6% involved a documented history of IVDU and 30% resulted in admission. 7% (315/4833) of patients received CT imaging, and 22% (70/315) of CTs demonstrated evidence of possible deep space or necrotizing infections. Patients with history of IVDU were more likely than patients without IVDU to receive a CT scan (18% vs 6%), have a CT scan with findings suspicious for deep-space or necrotizing infection (4% vs 1%), and undergo surgical drainage in the operating room within 48 h of arrival (5% vs 2%). Male sex, abnormal vital signs, and history of IVDU were each associated with higher likelihood of CT utilization. Encounters involving CT scans had longer median times to ED disposition than those without CT scans, regardless of whether these encounters resulted in admission (9.0 vs 5.5 h), ED observation (5.5 vs 4.1 h), or discharge (6.8 vs 2.9 h)., Discussion: ED clinicians ordered CT scans in 7% of encounters when evaluating for SSTI, most frequently in patients with abnormal vital signs or a history of IV drug use. Patients with a history of IVDU had higher rates of CT findings suspicious for deep space infections or necrotizing infections and higher rates of incision and drainage procedures in the OR. While CT scans significantly extended time spent in the ED for patients, this appeared justified by the high rate of actionable findings found on imaging, particularly for patients with a history of IVDU., Competing Interests: Declaration of Competing Interest All authors report no conflict of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Although superficial infections can often be diagnosed and managed clinically, physical examination may lack sensitivity and specificity, and imaging is often required to evaluate the depth of involvement and identify complications. Depending on the area of involvement, radiography, ultrasound, CT, MR imaging, or a combination of imaging modalities may be required. Soft tissue infections can be nonnecrotizing or necrotizing, with the later having a morbid and rapid course. Infectious tenosynovitis most commonly affects the flexor tendon sheaths of the hand, characterized by thickened and enhancing synovium with fluid-filled tendon sheaths., Competing Interests: Disclosure The authors have no conflicts of interest to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Musculoskeletal infections involve bones, joints, and soft tissues. These infections are a common clinical scenario in both outpatient and emergent settings. Although radiography provides baseline findings, a multimodality approach is often implemented to provide more detailed information on the extent of infection involvement and complications. MRI with intravenous contrast is excellent for the evaluation of musculoskeletal infections and is the most sensitive for diagnosing osteomyelitis. MRI, CT, and ultrasound can be useful for joint and soft tissue infections. When MRI or CT is contraindicated, bone scans and the appropriate utilization of other nuclear medicine scans can be implemented for aiding in the diagnostic imaging of infection, especially with metal hardware and arthroplasty artifacts on MRI and CT. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation., (Copyright © 2022 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Aims: To evaluate the effect of point-of-care ultrasound (POCUS) for the diagnosis of an abscess and to compare the diagnostic accuracy of POCUS and physical examination (PE) in paediatric patients with skin and soft tissue infections (SSTI) in the emergency department., Material and Methods: A comprehensive literature search was carried out to identify Englishlanguage studies on POCUS for differentiating an abscess from cellulitis in paediatric patients with SSTI. The quality of the study was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 tool, and pooled sensitivity and specificity of various POCUS findings were determined., Results: Seven studies with a total of 870 patients were included. There was significant heterogeneity across the included studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for the diagnosis of abscess by POCUS were 0.90 (95% confidence interval [CI], 0.82-0.95), 0.80 (95% CI, 0.72-0.86), 4.5 (95% CI, 3.1-6.4), 0.13 (95% CI, 0.07-0.23), and 36 (95% CI, 17-75), respectively, with an area under the curve (AUC) was 0.89 (95% CI, 0.86-0.91). Four studies provided data regarding the PE method. The pooled sensitivity, specificity, and AUC of PE for the abscess were 0.84 (95% CI, 0.80-0.88), 0.69 (95% CI, 0.62-0.76), and 0.85 (95% CI, 0.81-0.88)., Conclusions: POCUS is useful in identifying abscesses in paediatric patients with SSTI in emergency department, especially when PE is equivocal and outperforms PE alone.

Objective: To systematically review the accuracy of MRI and CT in diagnosing necrotizing soft tissue infection (NSTI)., Methods: MEDLINE and Embase were searched for original studies which reported the diagnostic performance of MRI or CT in detecting NSTI. Individual study quality was assessed using the QUADAS-2 tool. Sensitivity and specificity of MRI and CT were calculated and, if supported by data from at least two studies, pooled using a bivariate random-effects model., Results: Six MRI studies and 7 CT studies were included. There were no major concerns with regard to study quality and applicability. The included studies used multiple diagnostic criteria, with sensitivities and specificities of both MRI and CT ranging between 0 and 100%. T2 hyperintensity of deep fascia was the most commonly used diagnostic MRI criterion (5 studies), yielding a pooled sensitivity of 86.4% (95% confidence interval [CI] 76.1-92.7%) and a pooled specificity of 65.2% (95% CI 35.4-86.6%). Presence of gas was the most commonly used diagnostic CT criterion (3 studies), yielding a pooled sensitivity of 48.6% (95% CI 37.1-60.2%) and a pooled specificity of 93.2% (95% CI 73.3-98.5%)., Conclusion: T2 hyperintensity of deep fascia at MRI has high sensitivity and moderate specificity in diagnosing NSTI. Presence of gas at CT has low sensitivity but high specificity. A combination of diagnostic criteria may improve diagnostic performance, but this needs further investigation., (© 2021. ISS.)

Foot infections associated with soft tissue emphysema, or the radiographic appearance of gas, are widely considered to necessitate urgent decompression with excisional debridement of the necrotic and infectious tissue burden. The objective of this investigation was to describe anatomic features and clinical outcomes associated with the presence of soft tissue emphysema in foot infections. A retrospective chart review was performed of 62 subjects meeting selection criteria. These were primarily male (74.2%), with a history of diabetes mellitus (85.5%), and without a history of previous lower extremity revascularization (98.4%). The primary radiographic location of the soft tissue emphysema was most frequently in the forefoot (61.3%), followed by the midfoot (21.0%), and rearfoot (16.1%). The soft tissue emphysema was most frequently observed primarily in the dorsal foot tissue (49.2%), followed by both dorsal and plantar foot tissue (27.4%), and the plantar foot tissue (24.2%). The soft tissue emphysema was confined to the primary anatomic location in 74.2% of subjects, while 25.8% of cases demonstrated extension into a more proximal anatomic area. Eighty-two percent of subjects underwent a bedside incision and drainage procedure on presentation in the emergency department, and 95.2% underwent a formal incision and drainage procedure in the operating room at 1.05 ± 0.79 (0-5) postadmission days. Twenty-seven percent of subjects had an unplanned 30-day readmission and 17.7% underwent an unplanned reoperation within 30 days following the index discharge. Fifty-two percent of subjects underwent a minor or major amputation during the index admission, while 33.9% eventually resulted in major limb amputation within 12 months. We hope that this investigation adds to the body of knowledge and provides expectations with respect to the evaluation and treatment of foot soft tissue infections complicated by the presence of radiographic soft tissue emphysema., (Copyright © 2021 the American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: The aim: To detect the ultrasonographic signs of necrotizing fasciitis (NF) suitable for its early diagnosis., Patients and Methods: Materials and methods: Eigty two patients with soft tissue infection, including 14 with necrotizing faciitis, were examined by ultrasonography at the admission. Ultrasonografic features were compared to intraoperative findings by the same surgeon., Results: Results: The thickening of subcutaneous tissue had high sensitivity (100%), but low specificity (5.8%). The hypoechoic and hyperechoic zones had the shape of "cobblestone" with sensitivity - 78.5%, specificity - 33.8%. Higher specificity (69.1%) had sign of "cobblestone separation" on two layers. The presence of fluid above the fascia (sensitivity - 71.4%; specificity - 69.1%), thickening of the fascia (sensitivity - 85.7%; specificity - 58.8%), indistinctness of the fascia edges (sensitivity - 85.7%; specificity - 66.1%) and loss of fascial homogeneity (sensitivity - 71.4%, specificity - 66.1%) were noted in early stages of NF. Advanced cases of NF were accompanied by the dissection of thick¬ened fascia with a strip of fluid (sensitivity - 57.1%, specificity - 92.6%) and accumulation of a fluid under the fascia (sensitivity - 28.5%, specificity - 95.5%). The muscles thickening (sensitivity - 28.5%; specificity - 67.6%), skin thickening (sensitivity - 57.1%; specificity - 58.8%), and loss of the skin's lower edge clarity (sensitivity - 57.1%; specificity - 63.2%) don't have diagnostic value without other signs of NF., Conclusion: Conclusions: Point-of-care ultrasonography allows visualization of soft tissue changes that may be hidden in the initial stages of necrotizing fasciitis and should be recommended for implementation as mandatory method of examination in patients with suspected surgical soft tissue infection.

Objective: To investigate which computed tomography (CT) criteria are most useful in diagnosing necrotizing soft tissue infection (NSTI) and how CT performs with respect to the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score., Methods: Patients who underwent CT for suspected NSTI were eligible for inclusion. LRINEC score was assessed. CT scans were evaluated for subcutaneous edema, fluid along superficial fascia, fluid along deep fascia, blurring of intermuscular fat planes, fluid collection, and air in the soft tissues. Surgical findings or clinical follow-up served as reference standard., Results: Fourteen patients with NSTI and 34 patients with non-NSTI were included. LRINEC score was significantly higher in patients with NSTI (median of 7.5 vs. 6, p = 0.039). Fluid along the deep fascia was significantly more frequently present in patients with NSTI (46.2% vs. 5.9%, p = 0.001). In multiple logistic regression analysis, presence of fluid along the deep fascia was significantly associated with NSTI (odds ratio [OR] = 10.28, 95% CI: 1.57 to 67.18, p = 0.015), whereas the LRINEC score was not significantly associated with NSTI (OR = 1.27, 95% CI: 0.92 to 1.74, p = 0.146). Using presence of fluid along the deep fascia as diagnostic criterion for NSTI, sensitivity was 46.2% (95% CI, 23.2 to 70.9%) and specificity was 94.1% (95% CI, 80.9 to 98.4%)., Conclusion: Fluid along the deep fascia was the only CT criterion which was significantly associated with NSTI and appeared more useful than the LRINEC score. In the right clinical setting, presence of this CT finding is highly suggestive for NSTI. Its absence, however, does not rule out NSTI., Key Points: • The presence of fluid along the deep fascia at CT is highly suggestive for NSTI in suspected patients. Its absence, however, does not rule out NSTI. `• The use of fluid along the deep fascia as a criterion appears to be more useful than the LRINEC score in diagnosing NSTI., (© 2021. European Society of Radiology.)

The epitrochlear lymph nodes (ELN) are rarely examined clinically and are difficult to identify radiologically in healthy patients. They are, therefore, generally under appreciated as a source of significant pathology. Despite this, enlargement of an ELN is almost always secondary to a pathological process, the differential for which is relatively narrow. The following pictorial review illustrates the spectrum of infectious, inflammatory and malignant conditions affecting the ELN, some of which are quite specific to this location. We also emphasise the importance of distinguishing enlarged ELNs from benign and malignant non-nodal soft tissue masses, which can have very similar clinical presentation and imaging appearances.

Background: This study aimed to assess the risk factors, management, imaging validity, Laboratory Risk Indicator for Necrotising infection (LRINEC) score and outcomes of necrotising soft tissue infection (NSTI) at a western Sydney tertiary hospital., Methods: A retrospective study was conducted of all patients with NSTI from 2012 to 2019 at our institution. Patient characteristics, imaging, microbiology and site, LRINEC score, surgical management and outcomes/disposition were collected., Results: Thirty-six patients met the inclusion criteria with mean age of 52 years and body mass index of 38.1; 55.6% were male, 48% of Polynesian descent and 55.6% were diabetic. The most frequent sites of NSTI were perineal (30.6%), lower limb (30.6%), perianal (19.3%) and trunk (11.1%). A total of 64% of patients underwent computed tomography radiological imaging with diagnostic accuracy of 50%. The mean LRINEC score was 7 (1-20). A total of 52.8% were transferred from another facility or non-surgical teams which delayed surgical review by 11.4 h (P < 0.03) and operating time by 12.4 h (P < 0.04) compared with direct emergency department referrals to the on-call surgical team. There was no statistical difference in outcomes in both groups. The overall average time to surgical debridement was 16.2 h (standard deviation 19.6, range 3.4-105.1). The mean hospital length of stay was 20.9 days; 44.4% of patients were transferred for rehabilitation or plastic reconstruction with a single mortality from multi-organ failure., Conclusion: The optimal management of NSTI requires a high index of suspicion and LRINEC score is a useful adjunct in aiding a clinician's decision. Early surgical debridement within 24 h of diagnosis and a multidisciplinary approach is associated with a lower mortality rate., (© 2021 Royal Australasian College of Surgeons.)

Competing Interests: Competing interests: None declared.

Background: Skin and soft tissue infections (SSTIs) are an increasingly common complaint in the emergency department (ED), but physical examination does not reliably identify abscesses or accurately determine which skin lesions require incision and drainage. Point-of-care ultrasound (POCUS) improves management of soft tissue skin infections by detecting occult abscess, preventing unnecessary procedures, and identifying more complex disease requiring further imaging., Case Report: Here, we report a case in which POCUS drastically changed the management of what initially appeared to be an uncomplicated superficial skin abscess but was actually a much more serious mediastinal infection. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case underscores the importance and utility of POCUS to enhance the physical examination in suspected SSTIs. Because POCUS is easy, accurate, low risk, and can change management, we recommend its consideration as a standard component of the ED work up for SSTIs., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Skin and soft tissue infections (SSTIs) are a common complaint in the ambulatory setting and pose a significant burden on the health care system., Objectives: We sought to determine the accuracy of ultrasound for detecting soft tissue abscesses by emergency medicine associate providers (APs)., Methods: This was a prospective observational study of adult patients with suspected SSTI in the emergency department of a rural tertiary care academic medical center. The AP performed and interpreted point-of-care ultrasound (POCUS) of the suspected infected area. Ultrasound images and interpretation were reviewed by the attending emergency physician with either rejection or agreement of the image interpretation, diagnosis, and management. If incision and drainage was performed, presence or absence of purulent drainage was recorded., Results: Sixty-four patients with suspected SSTI were enrolled: 29 had POCUS-proven abscesses and 33 had cellulitis; 2 were excluded. AP clinical evaluation alone for identifying abscess revealed sensitivity of 92.3 (74.9-99.1), specificity of 67.7 (49.5-82.6), positive predictive value of 68.6 (57.0-78.2), and negative predictive value of 92.0 (81.4-100). The use of POCUS by APs in addition to clinical examination demonstrated sensitivity of 96.2 (80.4-99.9), specificity of 93.9 (79.8-99.3), positive predictive value of 92.6 (76.5-98.0), and negative predictive value of 96.9 (81.9-99.5). p values were <0.05 for test characteristics. Ultrasound results changed SSTI management decisions in 10 of 62 (16.1%) patients, with the most common change being a new incision and drainage or needle aspiration. Agreement of the POCUS interpretation between APs and attending physicians was 96.8% with a κ of 0.94 (0.85-1.00)., Conclusion: With modest training, APs can successfully use POCUS to identify abscesses in patients in the emergency department with SSTIs. POCUS increases the ability to rule in the diagnosis and changes management in a clinically relevant number of patients with SSTIs., (Copyright © 2020. Published by Elsevier Inc.)

The aim of the present study was to investigate clinical results and medico-legal aspects related to the surgical procedure of mini breast augmentation. In the present case, a 28-year-old young woman with bilateral mammary hypoplasia underwent surgery, under local anesthesia, with the placement of 150 cc breast implants in the sub-glandular plane. We report a case of dramatic isolated subcutaneous emphysema without pneumothorax and pneumomediastinum to be related in terms of a causal link to the surgical procedure which the patient underwent. The plastic surgeon proceeded to replace a breast implant that presumably, represented the vehicle of transmission of the suspected pathogen responsible for the infection, to become a causal role for the infectious manifestation. This case report is an emblematic example of the need for a careful and correct surgical procedure, in order to avoid serious consequences as in the case in question, burdened by the occurrence of unsafe conditions for the patient. Compliance with the guidelines and the technical datasheet of breast implants is essential in order to avoid the concrete hypothesis of professional liability. KEY WORDS: Aesthetic breast augmentation, Breast implant, Iatrogenic subcutaneous emphysema.

Objective: There is increasing evidence for the use of point-of-care ultrasound (POCUS) in pediatric patients with skin and soft tissue infections (SSTI), but there is a lack of sufficient data on its impact on SSTI outcomes. The objective of this study was to determine whether POCUS use is associated with fewer complications after discharge from the pediatric emergency department., Methods: This was a prospective cohort study in patients presenting to the emergency department with SSTI between the ages of 2 months and 19 years old. Adverse outcomes included hospitalization after discharge, change in antibiotics, subsequent procedures, or reevaluation by a medical professional. Outcome information was obtained 1 week later. Descriptive statistics and χ 2 tests were used., Results: Of 456 patients screened, 250 were enrolled. POCUS was performed on 113 (45%) patients. The median age was 5 years, with more females in the non-POCUS group compared with the POCUS group (58% vs. 52%). Cellulitis without abscess was more commonly diagnosed in the POCUS group than in the non-POCUS group (26% vs 14%, P = 0.02.) The patients in the non-POCUS group were more likely to undergo incision and drainage than those in the POCUS group (62% vs 45%, P = 0.008). Overall, a greater number of patients in the POCUS group did not undergo any procedure (45% vs 27%, P = 0.003). The outcomes at 1 week did not differ significantly between the two groups., Conclusions: POCUS use may lead to fewer procedures, but it does not lead to significantly better outcomes. Large randomized controlled trials are needed to confirm or refute our findings.

Competing Interests: Competing interests: None declared.

Melioidosis is endemic in many rural areas in Southeast Asia where facilities for culture and identification of Burkholderia pseudomallei are often limited. We performed a prospective observational study in patients presenting with fever to Mahosot Hospital, the primary referral hospital in Laos, to establish whether the detection of abscesses on ultrasound could support a presumptive diagnosis of melioidosis. All patients underwent ultrasound examination to detect abscesses in the liver, spleen, prostate, or, if indicated, subcutaneous tissue. We enrolled 153 patients, including 18 patients with melioidosis. Of these, 11 (61%) had an abscess at one or more sites, including five (28%) with splenic and/or liver abscesses. Absence of abscesses cannot rule out melioidosis, but the positive predictive value of abscesses for melioidosis was high at 93% (88-96%). Therefore, in endemic areas, the presence of abscesses in febrile patients should prompt empiric antibiotic therapy for melioidosis even in the absence of culture confirmation.

Hand infections can lead to significant morbidity if not treated promptly. Most of these infections, such as abscesses, tenosynovitis, cellulitis, and necrotizing fasciitis, can be diagnosed clinically. Laboratory values, such as white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and recently, procalcitonin and interleukin-6, are helpful in supporting the diagnosis and trending disease progression. Radiographs should be obtained in all cases of infection. Ultrasound is a dynamic study that can provide quick evaluation of deeper structures but is operator dependent. Computed tomographic and MRI studies are useful for evaluating deep space or bony infections and preoperative surgical planning., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Although MRI is the gold-standard imaging method in the diagnosis of spondylodiscitis, role of follow-up imaging is debated and there can be discrepancies with regard to the significance of bony or soft tissue responses to treatment. Purpose of our study is to test whether the MRI changes on follow-up imaging correlate with laboratory findings of treatment response., Methods: A total of 48 patients with pyogenic spondylodiscitis who underwent baseline and follow-up MRI were retrospectively reviewed. The extent of bone marrow edema, paravertebral soft tissue inflammation, and disc height were compared on baseline and follow-up MRIs with the C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels obtained from the medical records at baseline and on follow-up. Relationships between the MRI and laboratory changes were analyzed using the Spearmann correlation test., Results: The mean MRI follow-up period was 42.25 days. Based on the CRP (resolved: n = 19, resolving: n = 19, and aggravated: n = 10), there was significant correlation between the laboratory results and the changes in the bone and soft tissues (p < 0.01, both). The correlation was best with soft tissue changes (rho: 0.48) followed by bony changes (rho: 0.41). Based on the ESR (resolved: n = 8, resolving: n = 22, and worsened: n = 18), the correlation was stronger with bone changes (rho: 0.45, p < 0.01) than it was with soft tissue changes (rho: 0.39, p = 0.01)., Conclusion: Follow-up MRI findings of pyogenic spondylodiscitis show variable tissue responses. CRP was best correlated with soft tissue changes, while ESR showed the best association with bony changes.

Study Objective: Skin and soft tissue infections are a common chief complaint in the emergency department. Research has shown that clinical examination alone can be unreliable in distinguishing between cellulitis and abscesses, a distinction that is important because they each require different treatments. Point-of-care ultrasonography has been increasingly studied as a tool to improve the diagnostic accuracy for these skin and soft tissue infections. The primary objective of this systematic review is to evaluate the diagnostic accuracy of point-of-care ultrasonography for abscesses. Subgroup analyses are performed for adult versus pediatric patients and high suspicion versus clinically unclear cases. Secondary objectives include the percentage of correct versus incorrect changes in management and reduction in treatment failures because of point-of-care ultrasonography., Methods: PubMed, Scopus, Latin American and Caribbean Health Sciences Literature database, Cumulative Index of Nursing and Allied Health, Google Scholar, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were assessed from inception to July 26, 2019, for all prospective studies assessing the diagnostic accuracy of point-of-care ultrasonography for evaluation of skin and soft tissue abscesses. Data were dual extracted into a predefined work sheet and quality analysis was performed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Diagnostic accuracy was reported as sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR-), with 95% confidence intervals (CIs)., Results: We identified 14 studies comprising 2,656 total patients. Point-of-care ultrasonography was 94.6% sensitive (95% CI 89.4% to 97.4%) and 85.4% specific (95% CI 78.9% to 90.2%), with an LR+ of 6.5 (95% CI 4.4 to 9.6) and LR- of 0.06 (95% CI 0.03 to 0.13). Among cases with a high pretest suspicion for abscess or cellulitis, point-of-care ultrasonography was 93.5% sensitive (95% CI 90.4% to 95.7%) and 89.1% specific (95% CI 78.3% to 94.9%), with an LR+ of 8.6 (95% CI 4.1 to 18.1) and LR- of 0.07 (95% CI 0.05 to 0.12). Among cases that were clinically unclear, point-of-care ultrasonography was 91.9% sensitive (95% CI 77.5% to 97.4%) and 76.9% specific (95% CI 65.3% to 85.5%), with an LR+ of 4.0 (95% CI 2.5 to 6.3) and LR- of 0.11 (95% CI 0.03 to 0.32). Among adults, point-of-care ultrasonography was 98.7% sensitive (95% CI 95.3% to 99.8%) and 91.0% specific (95% CI 84.4% to 95.4%), with an LR+ of 10.9 (95% CI 6.2 to 19.2) and LR- of 0.01 (95% CI 0.001 to 0.06). Among pediatric patients, point-of-care ultrasonography was 89.9% sensitive (95% CI 81.8% to 94.6%) and 79.9% specific (95% CI 71.5% to 86.3%), with an LR+ of 4.5 (95% CI 3.1 to 6.4) and LR- of 0.13 (95% CI 0.07 to 0.23). Point-of-care ultrasonography led to a correct change in management in 10.3% of cases (95% CI 8.9% to 11.8%) and led to an incorrect change in management in 0.7% of cases (95% CI 0.3% to 1.1%)., Conclusion: According to the current data, point-of-care ultrasonography has good diagnostic accuracy for differentiating abscesses from cellulitis and led to a correct change in management in 10% of cases. Future studies should determine the ideal training and image acquisition protocols., (Copyright © 2020 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.)

Only a few studies and images of Tc-besilesomab scintigraphy are documented in the literature. We present a Tc-besilesomab image consistent with soft tissue infection of the lower limbs in a febrile 67-year-old man.

Point-of-care ultrasonography (POCUS) is performed by a physician at the bedside and is standard practice in obstetric, emergency, and musculoskeletal medicine. When compared with formal sonography, POCUS is equivalent in screening for abdominal aortic aneurysm and as accurate in diagnosing deep venous thrombosis. POCUS has high accuracy for diagnosing pneumonia and detecting acute decompensated heart failure but is less accurate than computed tomography for identifying pulmonary embolism. POCUS confirmation of intrauterine pregnancy rules out an ectopic pregnancy. In the third trimester of high-risk pregnancies, umbilical artery Doppler ultrasonography can improve perinatal outcomes. Musculoskeletal POCUS is used to diagnose and guide treatment of many joint and soft tissue conditions. It is as accurate as magnetic resonance imaging in the diagnosis of complete rotator cuff tears. Ultrasound guidance improves outcomes in the placement of central venous catheters and fluid drainage from body cavities and lumbar punctures. Ultrasonography can reduce the use of CT for diagnosis of appendicitis; however, negative scan results do not rule out disease. POCUS can accurately diagnose and rule out gallbladder pathology, and is effective for diagnosing urolithiasis. Focused cardiac ultrasonography can detect pericardial effusion and decreased systolic function, but is less accurate than lung ultrasonography at diagnosing acute heart failure. Limited evidence demonstrates a benefit of diagnosing testicular and gynecologic conditions. The American College of Emergency Physicians, the American Institute of Ultrasound in Medicine, the Society for Academic Emergency Medicine, the American College of Radiology, and others offer POCUS training. Training standards for POCUS have been defined for residency programs but are less established for credentialing.

Introduction: Skin and soft tissue infections (SSTI) occur along a continuum from cellulitis to abscess. Point-of-care ultrasound (POCUS) is effective in differentiating between these two diagnoses and guiding acute management decisions. Smaller and more superficial abscesses may not require a drainage procedure for cure. The goal of this study was to evaluate the optimal abscess size and depth cut-off for determining when a drainage procedure is necessary., Methods: We conducted a retrospective study of adult patients with a SSTI who had POCUS performed. Patients were identified through an ultrasound database. We reviewed examinations for the presence, size, and depth of abscess. Medical records were reviewed to determine acute ED management and assess outcomes. The primary outcome evaluated the optimal abscess size and depth when a patient could be safely discharged without a drainage procedure. We defined a treatment failure as a return visit within seven days requiring admission, change in antibiotics, or drainage procedure., Results: A total of 162 patients had an abscess confirmed on POCUS and were discharged from the ED without a drainage procedure. The optimal cut-off to predict treatment failure by receiver operating curve analysis was 1.3 centimeters (cm) in longest dimension with a sensitivity of 85% and specificity of 37% (area under the curve [AUC] 0.60, 95% confidence interval [CI], 0.44-0.76), and 0.4cm in depth with a sensitivity of 85% and specificity of 68% (AUC 0.83, 95% CI, 0.74-93)., Conclusion: This retrospective data suggests that abscesses greater than 0.4 cm in depth from the skin surface may require a drainage procedure. Those less than 0.4 cm in depth may not require a drainage procedure and may be safely treated with antibiotics alone. Further prospective data is needed to validate these findings and to assess for an optimal size cut-off when a patient with a skin abscess may be discharged without a drainage procedure.

Bone and soft tissue infection involving the foot is a serious complication of diabetes mellitus and represents a major public health and socioeconomic burden to National Health Services worldwide. Research in the past decade has improved diagnosis and treatment of these frequent and potentially devastating complications of diabetic foot which often remain difficult to be diagnosed and treated despite the availability of various clinical, serological, and imaging modalities. Furthermore, neuropathic osteoarthropathy can share many clinical and imaging features of osteomyelitis, and infection is often superimposed in patients with neuropathic disease. Thus, distinguishing between the two abnormalities is further complicated. Although the reference standard for diagnosis remains microbiologic analysis of bone specimens, in most clinical practice, soft tissue and bone infection involving the diabetic foot is diagnosed solely on the basis of a combination of clinical evaluation, serum inflammatory markers, and imaging modalities. Correlation between imaging findings and clinical features is very important as well as a common knowledge base for treatment team members rather than a compartmentalized view. Thus, the primary purpose of this review article was to provide radiologist and clinician with important clinical knowledge and relevant radiological semiotics, respectively, in order to facilitate a prompt diagnosis and personalised treatment of diabetic foot infections.

Musculoskeletal soft tissue infections are not uncommonly encountered in both the clinic and Emergency Department setting. The clinical diagnosis is not always evident as these infections can have variable presentations depending on the duration and depth of disease extension through the soft-tissue layers. Imaging often plays an important role in diagnosing the infection, defining the extent of involvement, directing tissue sampling, and in monitoring treatment response. After initial radiographs, ultrasound (US) is often the next modality utilized to evaluate patients with suspected soft tissue infections given its low cost, availability, portability, and potential for real-time guidance of fluid aspiration. The widespread use of cross-sectional imaging with magnetic resonance imaging (MRI) and computed tomography (CT) has greatly increased the radiological diagnosis in conditions where US may be limited. In addition, CT and MRI allow a thorough evaluation of disease extension, including assessment of joint spaces, tendons, and osseous changes indicative of bone involvement. This review will focus on the radiological findings of soft tissue infections on US, CT, and MRI., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Identifying infections of the deep neck spaces and understanding how they spread can be a diagnostic challenge that is complicated by complex anatomy and far-reaching clinical implications. Deep neck infections have the potential to quickly spread throughout the neck and chest, leading to widespread disease that can be rapidly fatal and resistant to treatment. This article provides a foundation for evaluating deep neck infections through a review of essential anatomy and a discussion of important diseases that interact with these spaces., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Nuclear medicine procedures, including Ga-67 and labeled leucocyte SPECT/CT as well as PET/CT using 18F-FDG and recently Ga-68 tracers, have found extensive applications in the assessment of infectious and inflammatory processes in general and in soft tissues in particular. Recent published data focus on summarizing the available imaging information with the purpose of providing the referring clinicians with optimized evidence based results. Guidelines and/or recommendations of clinical societies have incorporated nuclear medicine tests (using both labeled leucocytes and FDG) in their suggested work-up for evaluation of infective endocarditis and in certain patients with suspected vascular graft infections. Joint guidelines of the European and American nuclear medicine societies include fever of unknown origin, sarcoidosis, and vasculitis among the major clinical indications that will benefit from nuclear medicine procedures, specifically from FDG PET/CT. Limitations and pitfalls for the use of radiotracers in assessment of infection and inflammation can be related to patient conditions (eg, diabetes mellitus), or to the biodistribution of a specific radiopharmaceutical. Limited presently available data on the use of functional and/or metabolic monitoring of response to infectious and inflammatory processes to treatment and with respect to the effect of drugs such as antibiotics and glucocorticoids on the imaging patterns of these patients need further confirmation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Empyema necessitatis (EN) is a rare complication of empyema in which the pleural infection spreads outside the pleural space. Lower airway infections are common among children with cerebral palsy (CP). Although harmless to healthy individuals, Pseudomonas aeruginosa can cause invasive infections, including CP, in immunocompromised hosts. Mycobacterium tuberculosis and Actinomyces spp. have been reported as common causative organisms of EN. However, EN caused by P. aeruginosa has never been reported. We report the case of an 8-year-old girl with CP without tracheotomy who was admitted to our hospital with complaints of fever and increased epileptic seizures. First, she was diagnosed with pneumonia and treated with antibiotics. However, seven days after admission, a palpable mobile mass overlying the lower part of the shoulder blade was noticed. Enhanced magnetic resonance imaging revealed broad high signal area on T2-weighted and diffusion-weighted images, indicating empyema of the left lower lung that had penetrated the pleural wall and spread to the subcutaneous area of the left back. Thus, she was diagnosed with EN. Twelve days after admission, P. aeruginosa was detected from the pus culture. Patients with CP who have chronic lung diseases, such as pneumonia, atelectasis, or empyema, may need careful follow up., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Calf pain or swelling is a common presentation to the emergency department. The differential diagnoses are wide. Deep vein thrombosis (DVT) is often the first diagnosis to be excluded given its potentially fatal complications. Musculoskeletal causes of calf pain or swelling such as Baker's cyst, muscle or tendon tear, soft tissue infection, and inflammation are not uncommon and can often be confidently diagnosed with ultrasonography (US). Familiarity with these conditions and the sonographic findings would be useful in making timely and correct diagnosis.

Purpose: Characteristic swelling has been described as a differentiating sign of pyogenic flexor tenosynovitis (PFT) but has not been validated. We conducted a retrospective study of adults with finger infections to compare radiographic parameters of soft tissue dimensions. Our hypothesis was that in patients with digit infections, radiographic soft tissue thickness measurement would differ between PFT and non-PFT infected digits., Methods: Patients with a finger infection and radiographic evaluation were identified retrospectively at a large academic medical center and divided into 2 groups: PFT (n = 31) and non-PFT infections (n = 31). We defined PFT as purulence in the tendon sheath or positive culture growth from the sheath at surgery. Non-PFT infections included all other finger infections such as abscesses and cellulitis. A total of 15 radiographic measurements were made on all included digits. Ratios and differences were calculated to characterize the pattern of swelling for each infected finger. Bivariate analysis was performed to identify potential predictor variables between the PFT and non-PFT groups. Logistic regression was performed to reduce confounding and model potential relationships., Results: Neither presence of diffuse swelling nor the shape of finger swelling distinguished PFT from non-PFT infections. All finger infections resulted in diffuse swelling. Pyogenic flexor tenosynovitis was distinguished by differential volar soft tissue thickness minus dorsal soft tissue thickness on radiographs at the proximal phalanx level (9 ± 1 mm for PFT vs 5 ± 1 mm for non-PFT). This was an independent predictor of PFT. The area under the receiver operating curve was 0.83 (95% confidence interval, 0.73-0.94). A difference between volar and dorsal soft tissue swelling of 7 mm or greater had a positive predictive value of 82% with a sensitivity of 84% and specificity of 74%. A difference of 10 mm predicted PFT infection with 76% probability (95% confidence interval, 73% to 99%)., Conclusions: Pyogenic flexor tenosynovitis may result in uniform finger swelling, but this does not appear to distinguish PFT from other finger infections. Acute PFT swelling is distinguished by differential volar versus dorsal radiographic soft tissue thickness at the level of the proximal phalanx. The term "fusiform swelling" is a misnomer for the appearance of acute PFT because the finger is not spindle-shaped., Type of Study/level of Evidence: Diagnostic IV., (Copyright © 2019 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)