Critically ill patients often experience significant skeletal muscle wasting due to prolonged bed rest, metabolic disorders, inflammatory responses and malnutrition, which affects the patient's mobility and may also lead to increased mortality. Timely and accurate assessment of muscle status is important for optimizing treatment strategies and improving patient prognosis. There are various limitations in the current methods of assessing muscle mass, and muscle ultrasound, as a noninvasive, convenient, low-cost and suitable technique for bedside monitoring, has received increasing attention for its application in muscle assessment of critically ill patients. However, there are still a number of challenges in its practical application, such as the lack of uniform standards for the measurement method, the high dependence on the operation, and the reproducibility of the data that needs to be optimized, and so on. The aim of this article is to systematize the research progress of muscle ultrasound in muscle assessment of critically ill patients, and to discuss the advantages and limitations of its clinical application, in order to provide a scientific basis for future research and clinical practice.
Humans ; Critical Illness ; Ultrasonography ; Muscle, Skeletal/diagnostic imaging*

Hepatocellular carcinoma (HCC) is one of the most common malignancies and is a major cause of cancer-related mortalities worldwide (Forner et al., 2018; He et al., 2023). Sarcopenia is a syndrome characterized by an accelerated loss of skeletal muscle (SM) mass that may be age-related or the result of malnutrition in cancer patients (Cruz-Jentoft and Sayer, 2019). Preoperative sarcopenia in HCC patients treated with hepatectomy or liver transplantation is an independent risk factor for poor survival (Voron et al., 2015; van Vugt et al., 2016). Previous studies have used various criteria to define sarcopenia, including muscle area and density. However, the lack of standardized diagnostic methods for sarcopenia limits their clinical use. In 2018, the European Working Group on Sarcopenia in Older People (EWGSOP) renewed a consensus on the definition of sarcopenia: low muscle strength, loss of muscle quantity, and poor physical performance (Cruz-Jentoft et al., 2019). Radiological imaging-based measurement of muscle quantity or mass is most commonly used to evaluate the degree of sarcopenia. The gold standard is to measure the SM and/or psoas muscle (PM) area using abdominal computed tomography (CT) at the third lumbar vertebra (L3), as it is linearly correlated to whole-body SM mass (van Vugt et al., 2016). According to a "North American Expert Opinion Statement on Sarcopenia," SM index (SMI) is the preferred measure of sarcopenia (Carey et al., 2019). The variability between morphometric muscle indexes revealed that they have different clinical relevance and are generally not applicable to broader populations (Esser et al., 2019).
Humans ; Aged ; Sarcopenia/diagnostic imaging* ; Carcinoma, Hepatocellular/diagnostic imaging* ; Muscle, Skeletal/diagnostic imaging* ; Deep Learning ; Prognosis ; Radiomics ; Liver Neoplasms/diagnostic imaging* ; Retrospective Studies

Objective To investigate the clinical value of high-frequency ultrasound in the diagnosis of pronator teres syndrome (PTS). Methods The high-frequency ultrasound was employed to examine and measure the median nerve of the pronator teres muscle in 30 patients with PTS and 30 healthy volunteers (control group).The long-axis diameter (LA),short-axis diameter (SA) and cross-sectional area (CSA) of the median nerve were measured.The receiver operating characteristic curve of the median nerve ultrasonic measurement results was established,and the area under the curve (AUC) was calculated.The diagnostic efficiency of each index for PTS was compared with the surgical results as a reference. Results The PTS group showed larger LA[(5.02±0.50) mm vs.(3.89±0.41) mm;t=4.38,P=0.013],SA[(2.55±0.46) mm vs.(1.70±0.41) mm;t=5.19,P=0.009],and CSA[(11.13±3.72) mm² vs.(6.88±2.68) mm²;t=8.42,P=0.008] of the median nerve than the control group.The AUC of CSA,SA,and LA was 94.3% (95%CI=0.912-0.972,Z=3.586,P=0.001),77.7% (95%CI=0.734-0.815,Z=2.855, P=0.006),and 78.8% (95%CI=0.752-0.821,Z=3.091,P=0.004),respectively.With 8.63 mm² as the cutoff value,the sensitivity and specificity of CSA in diagnosing PTS were 93.3% and 90.0%,respectively. Conclusion High-frequency ultrasound is a practical method for diagnosing PTS,and the CSA of median nerve has a high diagnostic value.
Humans ; Forearm/innervation* ; Muscle, Skeletal/innervation* ; Median Nerve/diagnostic imaging* ; Ultrasonography/methods* ; Sensitivity and Specificity

Objective To determine the diagnostic accuracy of the intensity of fasciculation evaluated by muscle ultrasound in the differential diagnosis of amyotrophic lateral sclerosis (ALS). Methods We prospectively recruited patients who had ALS and neuropathy-radiculopathy attending Peking Union Medical College Hospital from 2017 to 2020. Healthy adults from a community were recruited as healthy controls. Muscle strength was assessed using the Medical Research Council (MRC) scale. At the first visit to the hospital, patients were assessed for maximal grade of fasciculations, total fasciculation score, and fasciculation grade in 16 muscle groups of bilateral upper and lower limbs using ultrasonography. The sensitivity and specificity of maximal grade of fasciculations, total fasciculation score, and fasciculation grade for the diagnosis of ALS were assessed by receiver operating characteristic analyses. Results The percentage of limb muscles with a maximal fasciculation grade higher than grade 2 in ALS patients and neuropathy-radiculopathy patients was 84.9% and 9.8%, respectively (χ² = 172.436, P < 0.01). Of the 16 limb muscles detected, the total fasciculation score [median (interquartile range)] was 29 (15, 41) in ALS patients and 3 (0, 8) in neuropathy-radiculopathy patients (Z = 9.642, P < 0.001). Remarkable fasciculations were seen in ALS patients whose muscles with a MRC score ranging from 2 to 4, followed by patients with MRC score 5, and then in those with MRC score 0 and 1. The sensitivity and specificity of total fasciculation score for diagnosis of ALS were 80.6% and 93.4%, respectively (cut-off value 14). In patients with ALS, for muscles with MRC score 4 and 5, the percentage of muscles with fasciculation grades ≥ 3 was 42.3% and 24.1% respectively, while in neuropathy-radiculopathy patients, the percentage for muscles with MRC score 4 and 5 was only 1.7% and 0, respectively. Conclusion A combined analysis of fasciculation intensity and MRC score of the limb muscles may be helpful for differential diagnosis of ALS.
Adult ; Humans ; Amyotrophic Lateral Sclerosis/diagnostic imaging* ; Fasciculation/diagnostic imaging* ; Radiculopathy ; Muscle, Skeletal/diagnostic imaging* ; Ultrasonography/methods*

OBJECTIVES: To summarize the skeletal muscle magnetic resonance imaging (MRI) features of the lower limbs in common subtypes of muscular dystrophy (MD) and the experience in the application of MRI in the diagnosis of MD. METHODS: A total of 48 children with MD who were diagnosed by genetic testing were enrolled as subjects. The muscle MRI features of the lower limbs were analyzed. Cumulative fatty infiltration score was calculated for each subtype, and the correlation of cumulative fatty infiltration score with clinical indices was analyzed for Duchenne muscular dystrophy (DMD). RESULTS: DMD was characterized by the involvement of the gluteus maximus and the adductor magnus. Becker muscular dystrophy was characterized by the involvement of the vastus lateralis muscle. Limb-girdle muscular dystrophy was characterized by the involvement of the adductor magnus, the vastus intermedius, the vastus medialis, and the vastus lateralis muscle. For DMD, the cumulative fatty infiltration score of the lower limb muscles was significantly correlated with age, course of the disease, muscle strength, and motor function (P<0.05), while it was not significantly correlated with the serum creatine kinase level (P>0.05). CONCLUSIONS Different subtypes of MD have different MRI manifestations, and MRI may help with the diagnosis and assessment of MD.
Child ; Humans ; Muscular Dystrophy, Duchenne/diagnostic imaging* ; Muscular Dystrophies, Limb-Girdle/pathology* ; Muscle, Skeletal/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Thigh/pathology*

skeletal muscle and callus was evaluated using contrast-enhanced ultrasonography (CEUS) in a canine osteotomy model to determine the applicability of CEUS in the assessment of neovascularization during fracture healing and to compare the vascular signals on CEUS between external skeletal fixation and cast-applied dogs. In 6 Beagle dogs, a simple transverse osteotomy was performed at the left tibial shaft and external skeletal fixation (n = 3) or a cast (n = 3) was applied. Radiography, power Doppler ultrasonography (power Doppler), and CEUS were performed until complete union was achieved. On CEUS, vascular changes were quantitatively evaluated by measuring peak intensity (PI) and time to PI in the soft tissue and callus and by counting the vascular signals. Vascular signals from the soft tissue were detected on power Doppler and CEUS on day 2. Significantly more vascular signals were detected by CEUS than by power Doppler. On CEUS, PI in the surrounding soft tissue was markedly increased after the fracture line appeared indistinctively changed on radiography in all dogs. In the cast-applied dogs, vascular signals from the periosteal and endosteal callus were detected on CEUS before mineralized callus was observed on radiography. CEUS was useful in assessing the vascularity of soft tissue and callus, particularly in indirect fracture healing, and provided indications of a normally healing fracture.]]>
Animals ; Bony Callus ; Diagnostic Imaging ; Dogs ; Fracture Fixation ; Fracture Healing ; Microbubbles ; Miners ; Muscle, Skeletal ; Osteotomy ; Perfusion ; Radiography ; Ultrasonography ; Ultrasonography, Doppler

OBJECTIVE: To reconstruct a three-dimensional model of female urinary system based on magnetic resonance imaging (MRI) and tomography angiography (CTA) data. METHODS: MRI and CTA datasets were collected from 20 patients in our department in 2018 for reconstructing 3D models of the bladder urethra in resting state using Mimics19.0 software combined with engineering software. The metric parameters of the bladder urethra were analyzed in the reconstructed 3D model. RESULTS: The bladder and urethra were successfully reconstructed using 10 MRI datasets, and the kidney, ureter and bladder were reconstructed using 10 CTA datasets. Using engineering software, we measured a number of cysto-urethral geometric parameters, including the cysto-urethral posterior angle (151.1±17.9°), beta angle (137.3±14.0°), urethral pubic angle (47.8± 12.1°), urethral tilt angle (21.5±7.3°), alpha angle (83.8±13.8°), the posterior pubic space (15.3±3.0 mm), and the urethral striated muscle thickness (2.6±0.6 mm). CONCLUSIONS Three-dimensional reconstruction of the anatomical model of the human urinary system provides a platform for studying the fine anatomy of the female urinary system and allows measurement of multiple parameters to better understand the functional differences of the bladder and urethra in different populations.
Female ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; Models, Anatomic ; Muscle, Skeletal ; Tomography, X-Ray Computed ; Urethra ; diagnostic imaging ; Urinary Bladder ; diagnostic imaging

To explore the value of conventional ultrasound combined with shear-wave elastography in the quantitative evaluation of sciatic nerve crush injury in rabbit models. Forty healthy male New Zealand white rabbits were randomly divided into four groups (=10 in each group):three crush injury (CI) groups (2,4,and 8 weeks after crush) and control group (without injury). The thickness and stiffness of the crushed sciatic nerves and denervated triceps surae muscles were measured at different time points and compared with histopathologic parameters. Inter-reader variability was assessed with intraclass correlation coefficients. Compared with the control group,the inner diameters of the sciatic nerves significantly increased in the 2-week CI group [(1.65±0.34) mm (0.97±0.15) mm,=0.00] but recovered to the nearly normal level in the 8-week CI group [(1.12±0.18) mm (0.97±0.15) mm,=0.06];however,compared with control group [(8.75±1.02)kPa],the elastic modulus of the nerves increased significantly in all the CI groups [2-week:(14.77±2.53) kPa;4-week:(19.12±3.46) kPa;and 8-week:(28.39±5.26) kPa;all =0.00];pathologically,massive hyperplasia of collagen fibers were found in the nerve tissues. The thickness of denervated triceps surae muscle decreased gradually,and the elastic modulus decreased 2 weeks after injury but increased gradually in the following 6 weeks;pathologically,massive hyperplasia of collagen fibers and adipocytes infiltration were visible,along with decreased muscle wet-weight ratio and muscle fiber cross-sectional area. The inter-reader agreements were good. Conventional ultrasound combined with shear-wave elastography is feasible for the quantitative evaluation of the morphological and mechanical properties of crushed nerves and denervated muscles.
Animals ; Crush Injuries ; diagnostic imaging ; Elastic Modulus ; Elasticity Imaging Techniques ; Male ; Muscle, Skeletal ; innervation ; pathology ; Rabbits ; Random Allocation ; Sciatic Nerve ; injuries ; Ultrasonography

BACKGROUND: Late-onset multiple acyl-coA dehydrogenase deficiency (MADD) is an autosomal recessive inherited metabolic disorder. It is still unclear about the muscle magnetic resonance image (MRI) pattern of the distal lower limb pre- and post-treatment in patients with late-onset MADD. This study described the clinical and genetic findings in a cohort of patients with late-onset MADD, and aimed to characterize the MRI pattern of the lower limbs. METHODS: Clinical data were retrospectively collected from clinic centers of Peking University People's Hospital between February 2014 and February 2018. Muscle biopsy, blood acylcarnitines, and urine organic acids profiles, and genetic analysis were conducted to establish the diagnosis of MADD in 25 patients. Muscle MRI of the thigh and leg were performed in all patients before treatment. Eight patients received MRI re-examinations after treatment. RESULTS: All patients presented with muscle weakness or exercise intolerance associated with variants in the electron transfer flavoprotein dehydrogenase gene. Muscle MRI showed a sign of both edema-like change and fat infiltration selectively involving in the soleus (SO) but sparing of the gastrocnemius (GA) in the leg. Similar sign of selective involvement of the biceps femoris longus (BFL) but sparing of the semitendinosus (ST) was observed in the thigh. The sensitivity and specificity of the combination of either "SO+/GA-" sign or "BFL+/ST-" sign for the diagnosis of late-onset MADD were 80.0% and 83.5%, respectively. Logistic regression model supported the findings. The edema-like change in the SO and BFL muscles were quickly recovered at 1 month after treatment, and the clinical symptom was also relieved. CONCLUSIONS This study expands the clinical and genetic spectrums of late-onset MADD. Muscle MRI shows a distinct pattern in the lower limb of patients with late-onset MADD. The dynamic change of edema-like change in the affected muscles might be a potential biomarker of treatment response.
Adolescent ; Adult ; Biopsy ; methods ; Carnitine ; analogs & derivatives ; blood ; Electron-Transferring Flavoproteins ; genetics ; Female ; Hamstring Muscles ; diagnostic imaging ; metabolism ; pathology ; Humans ; Iron-Sulfur Proteins ; genetics ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Multiple Acyl Coenzyme A Dehydrogenase Deficiency ; diagnostic imaging ; genetics ; pathology ; Muscle, Skeletal ; diagnostic imaging ; metabolism ; pathology ; Oxidoreductases Acting on CH-NH Group Donors ; genetics ; Retrospective Studies ; Young Adult

Muscle is one of the most important tissues of human body, which is distributed around various organs and bones. Skeletal muscle plays an important role in human activities and its functional changes are closely related to its own morphological structure. The study of the relationship between musculoskeletal structure and function can help us to understand the physiology basics of force and to guide clinical practices. Ultrasonography has been widely used in the research of muscle properties since it is real-time, fast, nonradiative and inexpensive. In recent years, there emerges various researches on image processing method for musculoskeletal ultrasonography, especially for dynamic ultrasonography. This paper presents a brief overview of the existing methods and key steps of ultrasound image processing of musculoskeletal.
Humans ; Image Processing, Computer-Assisted ; Muscle, Skeletal ; diagnostic imaging ; Ultrasonography