Artifacts in Musculoskeletal Ultrasonography: From Physics to Clinics

Ultrasonographic Evaluation of Solid Organ Sizes in Children with Primary Malnutrition: A Preliminary Study

Objectives: Malnutrition is a common health problem affecting overall body functions, growth, and development. The aim of the present study was to explore any potential changes in solid organ sizes due to malnutrition and, if so, their correlation with the degree of malnutrition. Materials and Methods: Solid organ sizes (liver, spleen, and kidneys) in patients with primary malnutrition were measured prospectively using ultrasonography. Results: A correlation was observed between changes in liver, spleen, and kidney sizes and left kidney parenchymal thickness and the degree of malnutrition in patients. Conclusions: The presence and degree of malnutrition were directly proportional to significant decreases in organ sizes. The present study is the first to reveal a positive correlation between anthropometric measurement Z scores and organ sizes.

Monitoring focused ultrasound ablation surgery (FUAS) using echo amplitudes of the therapeutic focused transducer

OBJECTIVE

B-mode sonography is commonly used to monitor focused ultrasound ablation surgery (FUAS), but has limitations in sensitivity. More accurate and reliable prediction of coagulation is required.

METHODS

The focused ultrasound (FUS) transducer was adapted for echo reception. Numerical simulations compared the normalized echo amplitudes from the FUS transducer and imaging probe at varying tissue depths and frequencies with a 3 mm necrosis at focus. An ex vivo experiment then evaluated echo changes from the FUS transducer and ultrasound imaging probe under different settings. Finally, coagulation prediction using FUS echo data was compared to sonography in a clinical ex vivo context.

RESULTS

The echo amplitudes from the FUS transducer exhibit a less pronounced decline with increasing tissue penetration depth compared to the ultrasound imaging probe. In ex vivo bovine liver experiments at depths of 2 cm and 4 cm, the FUS transducer detected normalized echo amplitudes that were significantly larger (i.e., 2∼3 folds) than those received by the ultrasound imaging probe. Moreover, multi-layered ex vivo tissue experiments that replicate clinical conditions revealed that coagulation prediction utilizing the FUS transducer's echo amplitudes achieved superior accuracy (91.2% vs. 60.3 %), sensitivity (92.1% vs. 54.5 %), and negative prediction (78.9% vs. 30.6 %), but similar specificity (88.2% vs. 84.6 %) and positive prediction (95.9% vs. 93.8 %) in comparison to sonography.

CONCLUSION

The echo amplitude of the FUS transducer serves as a sensitive and dependable metric for monitoring the FUAS outcomes. Its utilization may augment the procedure's safety and efficacy.

Diagnostic Musculoskeletal Ultrasound for Medial Collateral Ligament Injuries: Applications in Rehabilitation

Medial collateral ligament (MCL) injuries are prevalent in sports and other physical activities and constitute a significant cause of knee pain and dysfunction. Traditional diagnostic modalities such as magnetic resonance imaging (MRI) are often utilized for their detailed visualization capabilities. However, musculoskeletal ultrasound (MSK-US) has emerged as a pivotal diagnostic tool in the evaluation of MCL injuries due to its non-invasive nature, cost-effectiveness, and dynamic imaging capabilities. This article reviews the utility and advantages of MSK-US in diagnosing MCL injuries, with a specific focus on its implications for rehabilitation providers. We discuss the technical aspects of ultrasound (US) imaging, including the sonographic appearance of MCL injuries across various grades, and compare its diagnostic accuracy with other imaging modalities such as MRI. Additionally, the role of US in monitoring the healing process and guiding rehabilitation strategies is explored. This review emphasizes the practical application of MSK-US in clinical settings, offering rehabilitation providers a comprehensive understanding of how US can be integrated into patient management protocols to enhance outcomes in patients with MCL injuries.

Current status of dynamic musculoskeletal ultrasound for application to treatment of orthopedic diseases

In recent years, dynamic musculoskeletal ultrasound (DMUS) technology has demonstrated great potential in the diagnosis and treatment of orthopedic diseases. As a non-invasive, real-time imaging technique, it provides a dynamic view of joints and soft tissues, offering crucial insight for evaluating muscle injuries and bone damage caused by motion. This article comprehensively reviews the latest research in the field of DMUS, discussing its significant roles in managing orthopedic diseases and enhancing clinical practice. The application of DMUS is wide-ranging, including but not limited to the diagnosis of tendon injuries, ligament tears, arthritis, and soft tissue diseases. Additionally, DMUS has significant value in monitoring treatment progress and evaluating post-operative recovery. Furthermore, we discuss the use of DMUS for improving the accuracy and effectiveness of orthopedic surgeries. DMUS can provide high-quality diagnostic and therapeutic services for patients without a need for expensive equipment or complex procedures. Despite its promising outlook in orthopedics, broader clinical adoption remains limited by factors such as the steep learning curve associated with its use, the demand for specialized skills in interpreting high-quality images, and the need for extensive clinical validation. Future research should focus on standardizing operational procedures, improving the automation of image analysis, and validating its application in different orthopedic diseases through clinical trials.

Ultrasound imaging in crystal arthropathies: a pictorial review

OBJECTIVE

The prevalence of crystal arthropathies in the general population is rising. The purpose of this pictorial study is to describe the sonographic elements of the most prevalent crystal arthropathies by emphasizing particular sonographic findings using illustrative images and cases while considering technical details and common pitfalls.

METHODS

Using established recommendations, specialists in the fields of sonography and crystal arthropathies agreed by consensus on the unique ultrasound signs associated with each of the conditions.

RESULTS

Gout, calcium pyrophosphate deposition arthropathy, and hydroxyapatite arthropathy are the three most prevalent crystal arthropathies. Today's high-resolution sonography enables reliable evaluation of the underlying crystal deposits, post-inflammatory changes, and a precise description of joint inflammation.

CONCLUSIONS

High-prevalence crystal arthropathies are reliably detectable by ultrasound with current ultrasound equipment. It is necessary to have extensive ultrasound training, know specific sonographic findings, and understand all possible differential diagnoses for disorders affecting the musculoskeletal system.

Free scan real time 3D ultrasound imaging with shading artefacts removal

Ultrasound imaging (USI) is a widely adopted imaging method in clinical diagnosis owing to its low cost, convenience, and safety. However, due to the complex acoustic attenuation, two-dimensional (2D) USI lacks the capability to achieve a clear imaging result when the target is shaded by high echo tissues. This paper proposes a three-dimensional (3D) free-scan real-time ultrasound imaging (FRUSI) method. By integrating 2D ultrasound image sequences around the region of interest (ROI) with a real-time and spatially accurate probe tracking method, the proposed FRUSI system provides clear and accurate ultrasound images for medical study. The experiment results on reconstruction precision and accuracy show the potential ability of our proposed system to provide high-quality 3D ultrasound imaging. Moreover, previously shaded targets can be discerned clearly in the same scan plane in both phantom studies and in vivo studies on the human finger joint. The performance of the proposed FRUSI system has demonstrated its potential value for clinical diagnosis to provide high ultrasound imaging quality and rich details in spatial information. Due to the convenient setup, the FRUSI system might potentially be expanded to other ultrasound imaging modalities.

Ultrasound-guided injection of the hip: Cadaveric description for the lateral approach

BACKGROUND

Ultrasound (US)-guided intraarticular hip joint injections are commonly performed using an in-plane anterior approach, which has several limitations.

OBJECTIVE

To describe and report a "lateral" (lateral to medial) approach for US-guided intraarticular hip injection.

DESIGN

Cadaveric investigation.

SETTING

Academic institution, department of anatomy.

PARTICIPANTS

One cadaveric specimen.

METHODS

Both hips of a single cadaver were injected using the US-guided lateral approach. In the left hip, the needle was inserted and kept in situ. The right hip was injected with white-colored water-diluted latex dye. Subsequently, a layer-by-layer anatomical dissection was performed.

MAIN OUTCOME MEASURES

Presence and distribution of latex dye and location of needle tip within the joint capsule of the hip.

RESULTS

Anatomical dissection of the left and right hips confirmed the correct intraarticular position of the needle tip and the placement of the latex dye, respectively. During layer-by-layer dissection of the left hip, positions of the lateral cutaneous nerve and the lateral circumflex femoral artery were observed anterior to the needle, 30 mm for the nerve and 8 mm for the artery.

CONCLUSIONS

This preliminary study demonstrated that the US-guided lateral approach is a convenient technique to access the hip joint in a cadaveric specimen. Compared with the "classical" anterior technique, the lateral approach may provide several advantages, including improved needle visibility, theoretically decreased risk of vascular injury, and less risk of needle contamination. Because injury to the lateral epiphyseal arteries is possible when lateral approach is used, caution is required, especially in children. These preliminary conclusions will need to be validated in future/larger clinical studies.

Anatomy and Sonographic Examination for Lateral Epicondylitis: EURO-MUSCULUS/USPRM Approach

OBJECTIVE

The aim of the study is to define a standardized comprehensive sonographic approach for evaluating the different histoanatomical compartments of the lateral elbow.

DESIGN

Using high-frequency ultrasound probes, we tried to match the anatomical features of the lateral elbow and its different sonographic patterns in patients with the diagnosis of lateral epicondylitis. Moreover, high-sensitive color/power Doppler assessments have also been performed to evaluate the microcirculation.

RESULTS

Modern ultrasound equipment seems to provide an extremely detailed sonographic assessment of the different anatomical layers located in the lateral compartment of the elbow. Moreover, high-sensitive color/power Doppler imaging allows for clear visualization of the perfusion patterns in pathological conditions.

CONCLUSIONS

In clinical practice, high-frequency B-mode and high-sensitive color/power Doppler imaging can be integrated with the clinical findings to better define the pain generator(s) for optimizing the management of patients with lateral epicondylitis.

Ultrasound Imaging and Guidance for Cervical Myofascial Pain: A Narrative Review

Cervical myofascial pain is a very common clinical condition in the daily practice of musculoskeletal physicians. Physical examination is currently the cornerstone for evaluating the cervical muscles and identifying the eventual presence of myofascial trigger points. Herein, the role of ultrasound assessment in precisely localizing them is progressively mounting in the pertinent literature. Moreover, using ultrasound, not only the muscle tissue but also the fascial and neural elements can be accurately located/evaluated. Indeed, several potential pain generators, in addition to paraspinal muscles, can be involved in the clinical scenario of cervical myofascial pain syndrome. In this article, the authors extensively reviewed the sonographic approach for cervical myofascial pain in order to better diagnose or guide different procedures that can be performed in the clinical practice of musculoskeletal physicians.

Mnemonics and Metaphorical Videos for Detecting/Diagnosing Musculoskeletal Sonopathologies

ABSTRACT

Musculoskeletal ultrasound identifies a broad range of pathologies. Typical sonographic images of certain pathological/abnormal conditions can be rendered and "highlighted" for the daily practice/language of musculoskeletal sonographers. The following text and accompanying figures/videos represent a collection of findings pertaining to commonplace pathological conditions. This article is the second part of a series-after the characteristic/metaphoric descriptions of normal musculoskeletal structures.

From Histoanatomy to Sonography in Myofascial Pain Syndrome: A EURO-MUSCULUS/USPRM Approach

ABSTRACT

Myofascial pain is a common clinical condition, whereby accurate physical examination is usually considered as the cornerstone to identify/diagnose the "trigger point complex," that is, the characteristic finding of this syndrome. Considering the emerging role of ultrasound examination as the natural extension of physical assessment for musculoskeletal disorders, we briefly revise the histological/anatomical features of trigger points and propose a standardized, multistep sonographic approach to myofascial pain. We also imply that the integrated clinical-ultrasound evaluation could be considered as a potential tool to discriminate different phases/subsets of this challenging pathology.

From histology to sonography in synovitis: EURO-MUSCULUS/USPRM approach

OBJECTIVES

The aim of the present study was to propose a methodologically innovative sonographic approach for optimal evaluation of synovial tissues (starting from histopathology).

METHODS

Using high-frequency ultrasound probes and high-level ultrasound machines, we matched the histological microarchitecture of synovial tissues with multiple sonographic patterns in physiological and pathological conditions. Likewise, high-sensitive color/power Doppler assessments have also been performed to evaluate the microcirculation.

RESULTS

Modern equipment allows for a macroscopic classification of synovial pathologies recognizing different morphological patterns; however, intimal and subintimal layers of the synovium cannot be distinguished from each other on ultrasound. High-sensitive Doppler imaging clearly defines the microvascular pattern, especially in patients with hypertrophic synovial pathologies.

CONCLUSIONS

In clinical practice, using adequate technological equipment i.e. high-frequency B-mode and high-sensitive Doppler imaging, detailed sonographic assessment of synovial tissues can be performed - defining the main sono-histological patterns.

Ultrasound imaging of bone fractures

Ultrasound imaging is widely used to evaluate the neuromusculoskeletal system, and recently, a particular interest is mounting in assessing the bone tissue and fractures. Ultrasound can be considered a valuable diagnostic tool to perform a first-line evaluation of bone tissue, especially in particular settings without direct access to X-ray imaging and/or in emergency conditions. Moreover, different healing phases of bone fractures can be accurately assessed by combining the B-mode modality and (high-sensitive) color/power Doppler optimizing the management of patients-e.g., planning of progressive loads and rehabilitation procedures. In this review, we summarized the role of ultrasound imaging in the management of bone fractures and described the most common sonographic signs encountered in the daily practice by assessing different types of bone fractures and the progressive phases of the healing process.

Performance Evaluation of an Ultrasonic Imaging System Using Tissue-Mimicking Phantoms for Quality Assurance

Diagnostic ultrasound or sonography is an image that can provide valuable information for diagnosing and treating a variety of diseases and conditions. The aim of this research study is to examine the performance and accuracy of the ultrasonic imaging system for the guarantee of diagnosis quality assurance, and to adjust the penetration settings to minimize the time of repeat scans and maintenance duration during research experiments. Measurements in this experiment included the resolution (axial and lateral) and focal zones. Moreover, the evaluation was done by completing all the measurements at different depths on a multipurpose phantom model 539. The phantom was bought from the market and was not fabricated by the author. The measurements were achieved by applying two different transducers: curved and linear (flat). The ultrasound images were obtained and tested by using calipers (electronic), and the estimations and observations were read by using all the taken measurements and images. As a result, because the phantom depths were different, the penetration settings were different too, indicating that the depth impacted the penetrations of the created ultrasound image. Moreover, after the comparison of the recorded measurements and results, it was found that all measurements were within the accepted (standard) value and that the true value was specified by the production of the phantom.

Assessing/Imaging the Subcoracoid Space: From Anatomy to Dynamic Sonography

In the pertinent literature, standardized sonographic protocols have been widely described to evaluate the different compartments of the shoulder. However, the subcoracoid space is a complex anatomical region-usually not included/described in basic ultrasound approaches. Accordingly, starting from its anatomy, we describe a two-phase dynamic ultrasound protocol to scan the subcoracoid space. This way, we aim to optimize the diagnosis and management of patients with anterior shoulder pain and subcoracoid effusion.

From physical to ultrasound examination in lymphedema: a novel dynamic approach

In daily practice, medical history and physical examination are commonly coupled with anthropometric measurements for the diagnosis and management of patients with lymphatic diseases. Herein, considering the current progress of ultrasound imaging in accurately assessing the superficial soft tissues of the human body; it is noteworthy that ultrasound examination has the potential to augment the diagnostic process. In this sense/report, briefly revisiting the most common clinical maneuvers described in the pertinent literature, the authors try to match them with possible (static and dynamic) sonographic assessment techniques to exemplify/propose an 'ultrasound-guided' physical examination for different tissues in the evaluation of lymphedema.

Comparisons between skeletal muscle imaging techniques and histology in tracking midthigh hypertrophic adaptations following 10 weeks of resistance training

This study had two aims. AIM1 was to determine the agreement between mid-thigh vastus lateralis (VL) cross-sectional area measured by ultrasound (mCSA_US) versus magnetic resonance imaging (mCSA_MRI) at a single time point, and the ability of each to detect hypertrophic changes. AIM2 was to assess the relationships between pre-to-post training changes in thigh lean mass determined by DXA, VL mCSA_US, ultrasound-determined VL thickness (VL_Thick), and VL mean myofiber cross-sectional area (fCSA) with changes in VL mCSA_MRI. Twelve untrained males (Age: 20±1 y, BMI: 26.9±5.4 kg/m²; n=12) engaged in a 10-week resistance training program (2x/week) where right mid-thigh images and VL biopsies were obtained prior to and 72-hours following the last training bout. Participants' VL mCSA_MRI (p=0.005), DXA thigh lean mass (p=0.015), and VL_Thick (p=0.001) increased following training, whereas VL mCSA_US and fCSA did not. For AIM1, mCSA_US demonstrated excellent concordance (CCC = 0.830) with mCSA_MRI, albeit mCSA_US values were systematically lower compared to mCSA_MRI (mean bias: -2.29 cm²). Additionally, PRE-to-POST VL mCSA changes between techniques exhibited good agreement (CCC = 0.700; mean bias: -1.08 cm²). For AIM2, moderate, positive correlations existed for PRE-to-POST changes in VL mCSA_MRI and DXA thigh lean mass (r=0.580, p=0.048), mCSA_US (r=0.622, p=0.031), and VL_Thick (r=0.520, p=0.080). A moderate, negative correlation existed between mCSA_MRI and fCSA (r=-0.569, p=0.054). Our findings have multiple implications: i) resistance training-induced hypertrophy was dependent on the quantification method, ii) ultrasound-determined mCSA shows good agreement with MRI, and iii) tissue-level changes poorly agreed with mean fCSA changes and this requires further research.

EURO-MUSCULUS/USPRM Dynamic Ultrasound Protocols for Elbow

ABSTRACT

In this dynamic protocol, ultrasound examination of the elbow using different maneuvers is described for several/relevant elbow problems. Scanning videos are coupled with real-time patient examination videos for better understanding. The authors believe that this practical guide-prepared by an international consensus of several experts (EURO-MUSCULUS: European Musculoskeletal Ultrasound Study Group and USPRM: Ultrasound Study Group of ISPRM [International Society of Physical and Rehabilitation Medicine])-will help musculoskeletal physicians perform a better and uniform/standard approach.

Ultrasound-guided lumbar medial branch blocks and intra-articular facet joint injections: a systematic review and meta-analysis

Supplemental Digital Content is Available in the Text.

In this systematic review and meta-analysis, ultrasound-guided lumbar medial branch blocks and facet joint injections were associated with significant risk of incorrect needle placement.

There is great interest in expanding the use of ultrasound (US), but new challenges exist with its application to lumbar facet–targeted procedures. The primary aim of this systematic review and meta-analysis was to determine the risk of incorrect needle placement associated with US–guided lumbar medial branch blocks (MBB) and facet joint injections (FJI) as confirmed by fluoroscopy or computerized tomography (CT). An a priori protocol was registered, and a database search was conducted. Inclusion criteria included all study types. Risk of bias was assessed using the Cochrane risk of bias tool for randomized controlled trials and the National Heart, Lung, and Blood tool for assessing risk bias for observational cohort studies. Pooled analysis of the risk difference (RD) of incorrect needle placement was calculated. Pooled analysis of 7 studies demonstrated an 11% RD (P < 0.0009) of incorrect needle placement for US-guided MBB confirmed using fluoroscopy with and without contrast. Pooled analysis of 3 studies demonstrated a 13% RD (P < 0.0001) of incorrect needle placement for US-guided FJI confirmed using CT. The time to complete a single-level MBB ranged from 2.6 to 5.0 minutes. The certainty of evidence was low to very low. Ultrasound-guided lumbar MBB and FJI are associated with a significant risk of incorrect needle placement when confirmed by fluoroscopy or CT. The technical limitations of US and individual patient factors could contribute to the risk of incorrect needle placement.

Common and Uncommon Errors in Emergency Ultrasound

Errors in emergency ultrasound (US) have been representing an increasing problem in recent years thanks to several unique features related to both the inherent characteristics of the discipline and to the latest developments, which every medical operator should be aware of. Because of the subjective nature of the interpretation of emergency US findings, it is more prone to errors than other diagnostic imaging modalities. The misinterpretation of US images should therefore be considered as a serious risk in diagnosis. The etiology of error is multi-factorial: it depends on environmental factors, patients and the technical skills of the operator; it is influenced by intrinsic US artifacts, poor clinical correlation, US-setting errors and anatomical variants; and it is conditioned by the lack of a methodologically correct clinical approach and excessive diagnostic confidence too. In this review, we evaluate the common and uncommon sources of diagnostic errors in emergency US during clinical practice, showing how to recognize and avoid them.

Musculoskeletal Imaging for Dermatologists: Techniques in the Diagnosis and Management of Psoriatic Arthritis

Psoriatic arthritis is an inflammatory condition affecting up to 30% of patients with psoriasis. Patients may experience irreversible joint damage if not treated early, and diagnostic delays of even 6 months are associated with radiographic progression and impaired function. Therefore, early detection and intervention are of critical importance in patients with psoriatic arthritis. Given that psoriasis often precedes symptoms of psoriatic arthritis, dermatologists are uniquely positioned to identify patients with psoriatic arthritis early in their disease course, before permanent damage has occurred. Several screening tools have been developed to help dermatologists identify patients who may have psoriatic arthritis, but these tools may not capture patients with subclinical disease or quantify the type and severity of the underlying tissue insult, which is often the presenting sign of psoriatic arthritis. In these cases, a combination of clinical assessment and musculoskeletal imaging (e.g., ultrasound) is required. This review summarizes three common musculoskeletal imaging techniques used in the diagnosis and management of patients with psoriatic arthritis: conventional radiography, ultrasound, and magnetic resonance imaging. Further understanding of musculoskeletal imaging will assist dermatologists in making treatment decisions and allow them to have a more active role in the detection of psoriatic arthritis.

Ultrasound Frequency-Based Monitoring for Bone Healing

Correct assessment of the bone healing process is required for the management of limb immobilization during the treatment of bone injuries, including fractures and defects. Although the monitoring of bone healing using ultrasound poses several advantages regarding cost and ionizing radiation exposure compared with other dominant imaging methods, such as radiography and computed tomography (CT), traditional ultrasound B-mode imaging lacks reliability and objectivity. However, the body structures can be quantitatively observed by ultrasound frequency-based methods, and therefore, the disadvantages of B-mode imaging can be overcome. In this study, we created a femoral bone hole model of a rat and observed the bone healing process using the quantitative ultrasound method and micro-CT, which provides a reliable assessment of the tissue microstructure of the bone. This study analyzed the correlation between these two assessments. The results revealed that the quantitative ultrasound measurements correlated with the CT measurements for rat bone healing. This ultrasound frequency-based method could have the potential to serve as a novel modality for quantitative monitoring of bone healing with the advantages of being less invasive and easily accessible. Impact statement Bone healing monitoring with ultrasound is advantageous as it is less invasive and easily accessible; however, the traditional B-mode method lacks reliability and objectivity. This study demonstrated that the proposed ultrasound frequency-based monitoring method can quantitatively observe bone healing and strongly correlates with the computed tomography measurements for rat bone healing. This method has the potential to become a reliable modality for monitoring bone healing.

Sarcopenia Is Associated With Increased Risks of Rotator Cuff Tendon Diseases Among Community-Dwelling Elders: A Cross-Sectional Quantitative Ultrasound Study

Backgrounds: Recently, the association between sarcopenia and various musculoskeletal disorders, such as lumbar spine stenosis and fibromyalgia, has been highlighted. However, the relationship between sarcopenia and rotator cuff tendon diseases has rarely been investigated. This study aimed to evaluate whether sarcopenia was associated with shoulder pain and to determine whether rotator cuff tendons differed in echotexture between the sarcopenic and non-sarcopenic populations.

Methods: The thickness and echogenicity ratio of the tendon vs. the overlying muscle (ER_TM) or subcutaneous tissue (ER_TT) were measured using high-resolution ultrasonography in 56 sarcopenic patients and 56 sex- and age- matched controls. The association between ultrasound measurements of the rotator cuff tendon complex and sarcopenia was investigated using the generalized estimating equation (GEE).

Results: The sarcopenic group had an increased prevalence of shoulder pain. Based on the GEE analysis, sarcopenia was significantly associated with an increase in supraspinatus tendon thickness (β coefficient = 0.447, p < 0.001) and a decrease in the ER_TM for the biceps long head and rotator cuff tendons. A negative trend of association was observed between sarcopenia and ER_TT in the supraspinatus tendons (β coefficient = −0.097, p = 0.070). Nevertheless, sarcopenia was not associated with an increased risk of rotator cuff tendon tears.

Conclusions: Patients with sarcopenia have a higher risk of shoulder pain. A consistent tendinopathic change develops in the supraspinatus tendons in sarcopenic patients. However, sarcopenia is less likely to be associated with serious rotator cuff pathology, such as tendon tears. Prospective cohort studies are warranted to explore the causal relationship between sarcopenia and shoulder disorders.

Point-of-care ultrasound for the early diagnosis of emphysematous pyelonephritis: A case report and literature review

BACKGROUND

Emphysematous pyelonephritis (EPN) is a rare but fatal necrotic infection of the kidney, which usually leads to septic shock. Therefore, early diagnosis and optimized therapy are of paramount importance. In the past two decades, point-of-care ultrasound (POCUS) has been widely used in clinical practice, especially in emergency and critical care settings, and helps to rapidly identify the source of infection in sepsis. We report a rare case in which a “falls” sign on POCUS played a pivotal role in the early diagnosis of EPN.

CASE SUMMARY

A 57-year-old man presented with fever and lumbago for 3 d prior to admission. He went to the emergency room, and the initial POCUS detected gas bubbles in the hepatorenal space showing a hyperechoic focus with dirty shadowing and comet-tail artifacts. This imaging feature was like a mini waterfall. His blood and urine culture demonstrated Escherichia coli bacteremia, and EPN associated with septic shock was diagnosed. The patient did not respond to broad-spectrum antibiotic treatment and a perirenal abscess developed. He subsequently underwent computed tomography-guided percutaneous catheter drainage, and fully recovered. We also review the literature on the sonographic features of POCUS in EPN.

CONCLUSION

This case indicates that a “falls” sign on POCUS facilitates the rapid diagnosis of severe EPN at the bedside.

A Narrative Review of the Classification and Use of Diagnostic Ultrasound for Conditions of the Achilles Tendon

Enthesitis is a cardinal feature of spondyloarthropathies. The Achilles insertion on the calcaneus is a commonly evaluated enthesis located at the hindfoot, generally resulting in hindfoot pain and possible tendon enlargement. For decades, diagnosis of enthesitis was based upon patient history of hindfoot or posterior ankle pain and clinical examination revealing tenderness and/or enlargement at the site of the tendon insertion. However, not all hindfoot or posterior ankle symptoms are related to enthesitis. Advanced imaging, including magnetic resonance imaging (MRI) and ultrasound (US), has allowed for more precise evaluation of hindfoot and posterior ankle conditions. Use of US in diagnosis has helped confirm some of these cases but also identified other conditions that may have otherwise been misclassified without use of advanced imaging diagnostics. Conditions that may result in hindfoot and posterior ankle symptoms related to the Achilles tendon include enthesitis (which can include retrocalcaneal bursitis and insertional tendonopathy), midportion tendonopathy, paratenonopathy, superficial calcaneal bursitis, calcaneal ossification (Haglund deformity), and calcific tendonopathy. With regard to classification of these conditions, much of the existing literature uses confusing nomenclature to describe conditions in this region of the body. Some terminology may imply inflammation when in fact there may be none. A more uniform approach to classifying these conditions based off anatomic location, symptoms, clinical findings, and histopathology is needed. There has been much debate regarding appropriate use of tendonitis when there is no true inflammation, calling instead for use of the terms tendinosis or tendonopathy. To date, there has not been clear examination of a similar overuse of the term enthesitis in conditions where there is no underlying inflammation, thus raising the need for more comprehensive taxonomy.