Ultrasound-An Easy Available and Useful Point-of-Care Adjunct for Clinical Decision-Making in Hand Infections: Review of the Literature and a Case Series.

ABSTRACT: Initial findings of hand infections warrant a thorough treatment strategy depending on the progress of the infection. The decision for surgical treatment can be unclear. Searching to improve the quality of diagnostics, we reviewed the literature regarding the use of point-of-care ultrasound (PCUS) in hand infections and analyzed patients undergoing decision-making with PCUS. We searched PubMed, Scopus, Cochrane Register, and Google Scholar for the use of PCUS in therapy planning in infections of the hand. In addition, we screened our patients from July 1, 2020, to November 30, 2020, to validate the potential benefit of ultrasound examination in suspected hand infections. We evaluated initial clinical examinations versus blinded sonographic assessments in the context of correct decision to proceed with surgery or conservative treatment. Two thousand forty-eight studies within the topic were identified, but only 9 studies were found eligible to be included with a total of 88 patients. The studies illustrate that ultrasound can be performed on all patients, including children and pregnant women, and can be performed in a timely manner. In our retrospective analysis of 20 patients with suspected hand infection, the clinical and ultrasound assessment led to surgery in 13 cases. Of those 13 patients, 7 revealed intraoperative pus. By retrospective assessment of solely the ultrasound images, surgery would have been indicated in 9 cases, including all 7 cases with intraoperative pus. Clinical examination and ultrasound can help in detecting infections of the hand. Ultrasound examination, however, seems to yield a lower false-positive rate than clinical examination. Ultrasound could be a valuable addition to clinical examination.

Ultrasound protocol in odontogenic infections: a new proposal

Background: Point-of-care-ultrasound can be applied to preview a difficult airway, detect the presence of fluid collection, and soft-tissue edema, and guide the drainage location, although is rarely used. The purpose of this study is to validate a protocol for the assessment of these clinical features on patients with severe odontogenic infections.Material and methods: This was a single-group prospective cohort study (n=20) including patients with the diagnosis of deep-neck propagation of odontogenic infection. A transcervical linear high-frequency probe transducer (13-6 MHz) was used to scan the structures of the upper airway and the infectious collections. The drainage was guided by ultrasound and the patients were daily evaluated, according to the protocol. The data were extracted and the airway volume, midline deviation, and other important data such as length of hospital stay, dysphagia, voice alteration, raised floor of the mouth, dyspnea, and neck swelling were registered.Results: The ultrasound examination was correlated with multiple clinical findings, such as dyslalia (p=0,069), dysphagia (p=0,028), dyspnea (p=0,001), among others. This protocol has an advantage as it can be used at bedside evaluation, allowing the assessment of severe and unstable patients, and predicting the increase of the hospitalization time (p=0,019).Conclusions: This protocol is reliable for the assessment of the upper airway, even in an emergency, predicting not only the severity of the clinical features but aids in the determination of the length of the hospitalization time. (AU)

Ultrasound protocol in odontogenic infections: a new proposal.

BACKGROUND: Point-of-care-ultrasound can be applied to preview a difficult airway, detect the presence of fluid collection, and soft-tissue edema, and guide the drainage location, although is rarely used. The purpose of this study is to validate a protocol for the assessment of these clinical features on patients with severe odontogenic infections. MATERIAL AND METHODS: This was a single-group prospective cohort study (n=20) including patients with the diagnosis of deep-neck propagation of odontogenic infection. A transcervical linear high-frequency probe transducer (13-6 MHz) was used to scan the structures of the upper airway and the infectious collections. The drainage was guided by ultrasound and the patients were daily evaluated, according to the protocol. The data were extracted and the airway volume, midline deviation, and other important data such as length of hospital stay, dysphagia, voice alteration, raised floor of the mouth, dyspnea, and neck swelling were registered. RESULTS: The ultrasound examination was correlated with multiple clinical findings, such as dyslalia (p=0,069), dysphagia (p=0,028), dyspnea (p=0,001), among others. This protocol has an advantage as it can be used at bedside evaluation, allowing the assessment of severe and unstable patients, and predicting the increase of the hospitalization time (p=0,019). CONCLUSIONS: This protocol is reliable for the assessment of the upper airway, even in an emergency, predicting not only the severity of the clinical features but aids in the determination of the length of the hospitalization time.

Utility of Plasma Protein Biomarkers and Mid-infrared Spectroscopy for Diagnosing Fracture-related Infections: A Pilot Study.

OBJECTIVES: To compare a large panel of plasma protein inflammatory biomarkers and mid-infrared (MIR) spectral patterns in patients with confirmed fracture-related infections (FRIs) with those in controls without infection. DESIGN: Prospective case-control study. SETTING: Academic, Level 1 trauma center. PATIENTS: Thirteen patients meeting confirmatory FRI criteria were matched to 13 controls based on age, time after surgery, and fracture region. INTERVENTION: Plasma levels of 49 proteins were measured using enzyme-linked immunosorbent assay techniques. Fourier transform infrared spectroscopy of dried films was used to obtain MIR spectra of plasma samples. MAIN OUTCOME MEASUREMENTS: The main outcome measurements included plasma protein levels and MIR spectra of samples. RESULTS: Multivariate analysis-based predictive model developed using enzyme-linked immunosorbent assay-based biomarkers had sensitivity, specificity, and accuracy of 69.2% ± 0.0%, 99.9% ± 1.0%, and 84.5% ± 0.6%, respectively, with platelet-derived growth factor-AB/BB, C-reactive protein, and MIG selected as the minimum number of variables explaining group differences ( P < 0.05). Sensitivity, specificity, and accuracy of the predictive model based on MIR spectra were 69.9% ± 6.2%, 71.9% ± 5.9%, and 70.9% ± 4.8%, respectively, with 6 wavenumbers as explanatory variables ( P < 0.05). CONCLUSIONS: This pilot study demonstrates the feasibility of using a select panel of plasma proteins and Fourier transform infrared spectroscopy to diagnose FRIs. Preliminary data suggest that the measurement of these select proteins and MIR spectra may be potential clinical tools to detect FRIs. Further investigation of these biomarkers in a larger cohort of patients is warranted. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Non-cardiovascular findings on chest CT angiography in children with congenital heart disease: How important are they?

BACKGROUND: There are only a few publications about the non-cardiovascular findings in children with congenital heart diseases explored by chest CT angiography. The purpose of our study is to evaluate the prevalence of non-cardiovascular findings on chest CT angiographies in children with congenital heart disease and to raise awareness about their importance among the radiologists. METHODS: We retrospectively reviewed the 272 chest CT angiographies performed in our pediatric radiology department between January 2017 and march 2021 and extracted the data of the 180 patients positive for a congenital heart disease. Then from that pool, we sorted out the non-cardiovascular findings into significant and non-significant in regard of their relevance or not in the patient's management. RESULTS: Non-cardiovascular lesions were found in 58% (105/180) of our patients, and 49% (88/180) of them presented at least one significant non-cardiac lesion. Lung and airways abnormalities were found in 41% (74/180) of the cases, representing the majority of the non-cardiovascular findings. Syndromic associations were found in 17% (28/180) of our patients, including 14 cases of heterotaxic syndrome. CONCLUSION: Non-cardiovascular findings are common in children with congenital heart disease. Reporting these associated lesions is a requisite for an optimal therapeutic management of these children. Radiologists should never forget that a Chest CT angiography in children is first and foremost a chest CT.

Avoid the Phrase "No Drainable Fluid Collection" When Interpreting Examinations for Suspected Odontogenic Infection.

The phrase "no drainable fluid collection" harbors implicit management guidelines that may be inappropriate in regard to acute odontogenic infection. For many emergency department physicians, these words trigger a treatment plan involving antibiotics without drainage. However, many odontogenic infections require immediate drainage even when an abscess is not visible on imaging. As such, the phrase "no drainable fluid collection" should not be used when reporting on imaging performed for odontogenic infection.

Pediatric Musculoskeletal Infections: Imaging Guidelines and Recommendations.

Pediatric musculoskeletal infections often pose a diagnostic challenge due to their frequently vague and nonspecific clinical presentation. Imaging evaluation is a crucial component to diagnostic workup of these entities. Changed epidemiology of these infections over the past 2 decades has resulted in increases in both disease incidence and severity in the pediatric population. Prompt and accurate diagnosis is essential in order to reduce the risk of morbid sequelae, and to optimize patient management. In this article, the unique pathophysiology of musculoskeletal infections and characteristic imaging findings in children compared with adults are reviewed.

Role of thoracic and abdominal tomography in identifying a potential source of infection in patients with acute fever of unknown focus.

OBJECTIVES: The objective of this study was to evaluate the relationship between clinical features and the presence of infection on thoracic and abdominal tomography (CT) scans in emergency department (ED) patients with acute febrile illness without apparent source. METHODS: Patients aged 18 years and over who presented to ED with acute fever of unknown origin between January 1, 2020 and December 31, 2020 and underwent CT imaging (thoracic and abdomen) as a diagnostic test were included in the study retrospectively. Acute fever of unknown origin was defined as the absence of a history or physical examination finding that could explain the possible cause of fever, normal values of parameters that would suggest an infection in the urine analysis, and absence of infiltration on chest X-ray. The patients were divided into two groups according to the presence and absence of a source of infection on CT. The clinical and demographic data of the patients were evaluated. The effect of clinical factors on the presence of infection in CT scans was determined using the logistic regression analysis. RESULTS: Among the 173 patients included in the study, the CT scans were positive for the source of infection in 31.2% (n = 54) and negative in 68.8% (n = 119). In the multiple logistic regression analysis, age ≥ 65 years [odds ratio (OR): 2.72, 95% confidence interval (CI):1.15-4.35, p < 0.001), presence of comorbidity (OR:2.37, 95%CI:1.08-4.14, p = 0.033), and procalcitonin positivity (PCT) (OR: 2.54, 95%CI: 1.29-4.95, p = 0.006) were identified as risk factors for the presence of infection in CT. CONCLUSION: Patient's age, presence of comorbidity and PCT level should be considered when deciding on the use of CT in determining the source of infection in acute febrile patients without clinical clues.

Effect of a comprehensive deep-learning model on the accuracy of chest x-ray interpretation by radiologists: a retrospective, multireader multicase study.

BACKGROUND: Chest x-rays are widely used in clinical practice; however, interpretation can be hindered by human error and a lack of experienced thoracic radiologists. Deep learning has the potential to improve the accuracy of chest x-ray interpretation. We therefore aimed to assess the accuracy of radiologists with and without the assistance of a deep-learning model. METHODS: In this retrospective study, a deep-learning model was trained on 821 681 images (284 649 patients) from five data sets from Australia, Europe, and the USA. 2568 enriched chest x-ray cases from adult patients (≥16 years) who had at least one frontal chest x-ray were included in the test dataset; cases were representative of inpatient, outpatient, and emergency settings. 20 radiologists reviewed cases with and without the assistance of the deep-learning model with a 3-month washout period. We assessed the change in accuracy of chest x-ray interpretation across 127 clinical findings when the deep-learning model was used as a decision support by calculating area under the receiver operating characteristic curve (AUC) for each radiologist with and without the deep-learning model. We also compared AUCs for the model alone with those of unassisted radiologists. If the lower bound of the adjusted 95% CI of the difference in AUC between the model and the unassisted radiologists was more than -0·05, the model was considered to be non-inferior for that finding. If the lower bound exceeded 0, the model was considered to be superior. FINDINGS: Unassisted radiologists had a macroaveraged AUC of 0·713 (95% CI 0·645-0·785) across the 127 clinical findings, compared with 0·808 (0·763-0·839) when assisted by the model. The deep-learning model statistically significantly improved the classification accuracy of radiologists for 102 (80%) of 127 clinical findings, was statistically non-inferior for 19 (15%) findings, and no findings showed a decrease in accuracy when radiologists used the deep-learning model. Unassisted radiologists had a macroaveraged mean AUC of 0·713 (0·645-0·785) across all findings, compared with 0·957 (0·954-0·959) for the model alone. Model classification alone was significantly more accurate than unassisted radiologists for 117 (94%) of 124 clinical findings predicted by the model and was non-inferior to unassisted radiologists for all other clinical findings. INTERPRETATION: This study shows the potential of a comprehensive deep-learning model to improve chest x-ray interpretation across a large breadth of clinical practice. FUNDING: Annalise.ai.

Emerging applications of clinical ultrasonography.

In this work, we introduce the numerous emerging areas and frontiers in the use of point-of-care ultrasonography. Of these, we review the following three: 1) the use of clinical ultrasonography in infectious and tropical diseases (we address its usefulness in the diagnosis and follow-up of the main syndromes, in tropical diseases, and in areas with scarce resources); 2) the usefulness of clinical ultrasonography in the assessment of response to volume infusion in severely ill patients (we review basic concepts and the main static and dynamic variables used for this evaluation); and 3) the use of clinical ultrasonography in the assessment of muscle mass in elderly patients with primary sarcopenia (we review the main muscles and measurements used for it).

Infection imaging using [18F]FDG-labelled white blood cell positron emission tomography-computed tomography.

Localizing the sites of infection in the body is possible in nuclear medicine using a variety of radiopharmaceuticals that target different components of the infective and inflammatory cascade. Gamma(γ)-emitting agents such as [67Ga]gallium citrate were among the first tracers used, followed by development of positron-emitting tracers like 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG). Though these tracers are quite sensitive, they have limited specificity for infection due to their concentration in sites of non-infective inflammation. White blood cells (WBC) labelled with γ or positron emitters have higher accuracy for differentiating the infective processes from the non-infective conditions that may show positivity with tracers such as 18F-FDG. We present a pictorial review of potential clinical applications of PET/CT using 18F-FDG labelled WBC.

MRI of the Morel-Lavallée lesion - a case series.

INTRODUCTION: The aim of the study was to review the appearances of Morel-Lavallée (ML) lesions on magnetic resonance imaging (MRI). PATIENTS AND METHODS: 14 patients diagnosed with the ML lesion on MRI were analysed retrospectively (mean age = 35 years). Mechanism of injury, time frame from injury to MRI, location, shape, T1 and proton-density fat-suppression (PDFS) signal intensity (SI), presence of a (pseudo)capsule, septations or nodules within the collection, mass effect and fluid-fluid levels were analyzed. The Mellado and Bencardino classification was utilized to classify the lesions. RESULTS: In most cases, mechanism of injury was distortion. Mean time frame between the injury and MRI was 17 days. Lesions were located around the knee in 9 patients and in the peritrochanteric region in 5 patients. Collections were fusiform in 12 patients and oval in 2 patients. 9 collections were T1 hypointense and PDFS hyperintense. 4 collections had intermediate T1 and high PDFS SI. 1 collection had intermediate T1 and PDFS SI. (Pseudo)capsule was noted in 3 cases. Septations or nodules were found in 4 cases. According to the Mellado and Bencardino, collections were classified as seroma (type 1) in 9, subacute hematoma (type 2) in 1 and chronic organizing hematoma (type 3) in 4 cases. CONCLUSIONS: Characteristic features of ML lesion include a fusiform fluid collection between the subcutaneous fat and the underlying fascia after shearing injury. Six types can be differentiated on MRI, with the seroma, the subacute hematoma and the chronic organizing hematoma being the commonest.

Role of C-reactive protein in effective utilization of emergent MRI for spinal infections.

PURPOSE: Emergent spinal MRI is recommended for patients with back pain and red flags for infection. However, many of these studies are negative due to low prevalence of spinal infections. Our purpose was to assess if C-reactive protein (CRP) can be used to guide effective utilization of emergent MRI for spinal infections. METHODS: 316/960 (33%) MRIs performed for infection by the emergency department over 75-month period had CRP levels obtained at presentation, after excluding patients receiving antibiotic or had spinal surgery in < 1 month. An MRI was considered positive when there was imaging evidence of spinal infection confirmed on follow-up by surgery/biopsy/drainage or definitive therapy. A CRP of ≤ 10 mg/L was considered normal and > 100 mg/L as highly elevated. RESULTS: CRP was normal in 95/316 (30%) and abnormal in 221/316 (70%) patients. MRI was positive in 43/316 (13.6%) patients, all of whom had abnormal CRP. CRP (p < 0.001) and intravenous drug use (IVDU; p = 0.002) were independently associated with a positive MRI. Receiver operator characteristic (ROC) analysis showed AUC of 0.76 for CRP, slightly improving with IVDU. Sensitivity, specificity, and negative predictive values for CRP level cut-off: 10 mg/L, 100%, 35%, and 100%, and 100 mg/L, 58%, 70% and 91%, respectively. CONCLUSION: Abnormal CRP, although extremely sensitive, lacks specificity in predicting a positive MRI for spinal infection unless highly elevated. However, a normal CRP (absent recent antibiotic or surgery) makes spinal infection unlikely, and its routine use as a screening test can help reducing utilization of emergent MRI for this purpose.

MRI monitoring of macaque monkeys in neuroscience: Case studies, resource and normative data comparisons.

Information from Magnetic Resonance Imaging (MRI) is useful for diagnosis and treatment management of human neurological patients. MRI monitoring might also prove useful for non-human animals involved in neuroscience research provided that MRI is available and feasible and that there are no MRI contra-indications precluding scanning. However, MRI monitoring is not established in macaques and a resource is urgently needed that could grow with scientific community contributions. Here we show the utility and potential benefits of MRI-based monitoring in a few diverse cases with macaque monkeys. We also establish a PRIMatE MRI Monitoring (PRIME-MRM) resource within the PRIMatE Data Exchange (PRIME-DE) and quantitatively compare the cases to normative information drawn from MRI data from typical macaques in PRIME-DE. In the cases, the monkeys presented with no or mild/moderate clinical signs, were well otherwise and MRI scanning did not present a significant increase in welfare impact. Therefore, they were identified as suitable candidates for clinical investigation, MRI-based monitoring and treatment. For each case, we show MRI quantification of internal controls in relation to treatment steps and comparisons with normative data in typical monkeys drawn from PRIME-DE. We found that MRI assists in precise and early diagnosis of cerebral events and can be useful for visualising, treating and quantifying treatment response. The scientific community could now grow the PRIME-MRM resource with other cases and larger samples to further assess and increase the evidence base on the benefits of MRI monitoring of primates, complementing the animals' clinical monitoring and treatment regime.

Cerebral protothecosis mimicking high-grade glioma.

Prototheca wickerhamii is a common, indolent alga that seldom causes central nervous system infections in humans. We report the first UK case of cerebral protothecosis in an immunocompetent 56-year-old woman who presented with a 5-month history of intermittent fatigue followed by a 2-week history of symptoms, including right arm and leg weakness, a loss of fine motor coordination, worsening gait, right facial tingling, diplopia and a metallic oral taste. MRI scans revealed a multifocal abnormality suggestive of high-grade glioma. Given the clinical presentation, absence of immunodeficiency and characteristic MRI features, a diagnosis of high-grade glioma was deemed most likely by the multidisciplinary team. Surgical biopsy provided material for histopathological and microbiological diagnosis. She underwent a 2-year course of antimicrobials with surveillance MRI scans. The patient made a good functional recovery but still retains mild neurological sequelae.

Management of deep neck infections from cervical esophageal perforation caused by foreign body: A case series study.

PURPOSE: Esophageal perforation caused by foreign body is common in Chinese medical institutions, and resultant deep neck infections (DNI) is quite different from typical DNI. The purpose of this article was to share our experience on management of this particular type of DNI. MATERIAL AND METHODS: A retrospective review was conducted on a consecutive sample of such patients at Capital Medical University Beijing Friendship Hospital from 2015 to 2019. RESULTS: In total, 24 cases were recorded. CT scan of the neck and upper thorax was the most useful tool for early diagnosis. Gas formation was not predictive of a worse clinical course. Eleven patients with minor DNI were treated with antibiotics and foreign body removal; while 13 patients with major DNI were treated with neck incision and drainage, ICU observation, and prolonged usage of antibiotics. Outcome was generally good, but major complications, including sepsis and lingual artery rupture, could occur. CONCLUSIONS: Conservative management, focusing on prompt extraction of esophageal foreign body and adequate antibiotic coverage, can lead to good outcome for mild cases; while in addition to these measures, neck incision, cervical and superior mediastinal exploration, and high negative pressure drainage, should be performed for severe cases.

Value of antigranulocyte scintigraphy with Tc-99m-sulesomab in diagnosing combat-related infections of the musculoskeletal system.

AIM: Combat-related extremity injuries are regularly associated with long-term complications such as chronic infection, especially osteomyelitis. Clinical examination and laboratory parameters do not usually allow reliable diagnosis. In contrast, imaging techniques enable constructive assertions to be made about the location and extent of an infection of the peripheral musculoskeletal system. The aim of this study was therefore to determine the diagnostic reliability of three-phase bone scanning and antigranulocyte scintigraphy using Tc-99m-sulesomab (Leukoscan) in the diagnostic clarification of infections associated with combat-related extremity injuries. METHODS: Twenty-seven male patients (mean age 33.9 years) with suspected combat-associated infections of the extremities were included in this retrospective analysis. All patients underwent three-phase bone scanning using Tc-99m-HDP followed by antigranulocyte scintigraphy with Tc-99m-sulesomab. In 26 of the 27 patients, a CT scan of affected limb was obtained, where the secondary fusion with single photon emission CT data set was possible. The diagnostic reliability of imaging techniques was validated against microbiological samples obtained during surgery and used as gold standard. RESULTS: Three-phase bone scanning yielded a positive result in all patients, with 18 scans classified as true positive (TP) and nine scans as false positive (FP). This produced a sensitivity of 100%, a specificity of 0% and a positive predictive value (PPV) of 67%. Antigranulocyte scintigraphy recognised 13 patients as TP, 1 patient as FP, 8 patients as true negative (TN) and 5 patients as false negative (FN), which gave a sensitivity of 72%, a specificity of 88%, a PPV of 93%, a negative predictive value (NPV) of 62% and an accuracy of 78%. CT recognised in 7 cases a TP result, in 3 cases an FP, in 5 cases a TN and in 11 cases an FN result. This produced a sensitivity of 39%, a specificity of 63%, a PPV of 70%, an NPV of 31% and an accuracy of 46%. CONCLUSIONS: Three-phase bone scanning did not deliver any diagnostic benefit, since no result was able to differentiate unequivocally between infection-related and reactive changes. Antigranulocyte scintigraphy using Tc-99m-sulesomab represented a highly suitable technique for diagnostically clarifying combat-related infections of the extremities. It is superior to CT in sensitivity, specificity, PPV, NPV and accuracy.

MRI of Emergent Intracranial Infections and Their Complications.

Acute intracranial infections of the central nervous system and skull base are uncommon but time sensitive diagnoses that may present to the emergency department. As symptoms are frequently nonspecific or lack typical features of an infectious process, a high index of suspicion is required to confidently make the diagnosis, and imaging may not only serve as the first clue to an intracranial infection, but is often necessary to completely characterize the disease process and exclude any confounding conditions. Although computed tomography is typically the initial imaging modality for many of these patients, magnetic resonance imaging offers greater sensitivity and specificity in diagnosing intracranial infections, characterizing the full extent of infection, and identifying potential complications. The aim of this article is to serve as a review of the typical and most important imaging manifestations of these infections that can be encountered in the emergent setting.