The utility of ultrasound for diagnosing purulent infections of the upper extremity

Use of CEUS for Imaging Evaluation of Pediatric Peritonsillar Abscess

PURPOSE

Peritonsillar abscess can be diagnosed by B-mode ultrasound and cross-sectional imaging. The latter (with MRI being the modality of first choice in children) is associated with higher effort and risk for pediatric patients due to the administration of X-rays and/or the need of sedation. The purpose of this study is to evaluate whether the introduction of CEUS into the diagnostic algorithm for suspected pediatric peritonsillar abscess is suitable and advantageous.

MATERIALS AND METHODS

Single-institution retrospective review of data of pediatric patients who were presented to the department of pediatric radiology for sonographic evaluation under the suspicion of peritonsillar abscess. Diagnostic performance of CEUS was evaluated by using surgical exploration or clinical follow-up as the reference standard.

RESULTS

284 children included in the study underwent B-mode ultrasound. Mean age of all patients was 6,23 years. Peritonsillar abscess was the diagnosis in 42 patients. Diagnosis of peritonsillar abscess was made by B-mode ultrasound alone in 13 of 42 patients (31 %). In 17 of 42 patients (40 %), diagnosis was made by a combination of B-mode ultrasound and CEUS. Sensitivity rose from 37 % to 86 % in cases where B-mode ultrasound remained unclear and CEUS was used.

CONCLUSION

Contrast-enhanced ultrasound (CEUS) is suitable and efficient for the diagnosis of peritonsillar abscess in pediatric patients. It increases the sensitivity for the diagnosis of peritonsillar abscess and thereby reduces the need of additional cross-sectional imaging for the pediatric patients.

The Utility of Musculoskeletal Ultrasonography in Diagnosing Pyomyositis: A Comparison With Surgically and Conservatively Treated Cases

Objective:

The study aimed to determine the accuracy of sonography in diagnosing pyomyositis.

Methods:

A retrospective review of pyomyositis cases in a government hospital between January 1, 2016 and June 30, 2019 was done. All cases underwent a sonogram for the indication of pyomyositis. Positive purulence for surgical cases and improved laboratory parameters for conservative cases were confirmatory for pyomyositis. Comparison with sonographic results using a 2 × 2 contingency table was done to determine sensitivity and specificity.

Results:

A total of 122 cases were included. The sonographic results corresponded with 95% of surgical cases and 89% of conservative cases. A lack of false and true negatives for surgical cases resulted in a sensitivity of 100% (95% confidence interval [CI] = 93%–100%) and a specificity of 0% (95% CI = 0%–71%). In conservative cases, sonography had a sensitivity of 92% (95% CI = 82%–97%) and a specificity of 0% (95% CI = 0%–84%) due to a lack of true negatives.

Conclusion:

Sonography is not limited to primarily as a screening tool but a capable diagnostic imaging choice for pyomyositis, particularly in low-resource settings. The results show the strength of sonography, particularly in the suppurative stage of pyomyositis. [Box: see text]

Preclinical Evaluation of Photoacoustic Imaging as a Novel Noninvasive Approach to Detect an Orthopaedic Implant Infection

INTRODUCTION

Diagnosing prosthetic joint infection (PJI) poses significant challenges, and current modalities are fraught with low sensitivity and/or potential morbidity. Photoacoustic imaging (PAI) is a novel ultrasound-based modality with potential for diagnosing PJI safely and noninvasively.

MATERIALS

In an established preclinical mouse model of bioluminescent Staphylococcus aureus PJI, fluorescent indocyanine green (ICG) was conjugated to β-cyclodextrin (CDX-ICG) or teicoplanin (Teic-ICG) and injected intravenously for 1 week postoperatively. Daily fluorescent imaging and PAI were used to localize and quantify tracer signals. Results were analyzed using 2-way analysis of variance.

RESULTS

Fluorescence clearly localized to the site of infection and was significantly higher with Teic-ICG compared with CDX-ICG (P = 0.046) and ICG alone (P = 0.0087). With PAI, the photoacoustic signal per volumetric analysis was substantially higher and better visualized with Teic-ICG compared with CDX-ICG and ICG alone, and colocalized well with bioluminescence and fluorescence imaging.

CONCLUSION

Photoacoustic imaging successfully localized PJI in this proof-of-concept study and demonstrates potential for clinical translation in orthopaedics.