Migration of a pericardial drainage catheter into the right main pulmonary artery.

Migration of a pericardial drainage catheter into the right main pulmonary artery. If clinical symptoms of cardiac tamponade are unresolved and dense hemorrhagic fluid is evacuated after pericardial drain placement, this rare but lethal complication is a possibility.

Primary anastomosing hemangioma as a preoperative diagnostic mimicker of retroperitoneal cavernous hemangioma: A case report.

Anastomosing hemangioma (AH) is rare and a newly recognized variant of capillary hemangioma that is mostly found in the genitourinary tract. Additionally, AH is sometimes difficult to diagnose without pathological specimens. It is difficult to diagnose preoperatively due to the lack of specific clinical and radiologic appearance. The present report describes the imaging features from a radiological perspective and outlines the clinicopathologic features and treatment options. A 67-year-old woman was referred to Dokkyo Medical University Saitama Medical Center (Koshigaya, Japan) for a retroperitoneal tumor that was identified at a medical checkup 4 years prior. The patient had no symptoms, no abnormal physical signs and no past medical or specific family history. Routine blood tests were all within the normal ranges. A nonenhanced CT scan showed a circular, homogenous, well-circumscribed retroperitoneal tumor that was ~32×23 mm in size, between the abdominal aorta and the inferior vena cava, and just below the left renal vein. On a contrast-enhanced multidetector CT scan, the tumor showed heterogeneous septal enhancement in the arterial phase and persistent enhancement in the portal phase. The tumor was diagnosed as a benign neurogenic tumor or a retroperitoneal cavernous hemangioma at the time, and the patient was intended to be followed up at the outpatient clinic. However, it gradually increased to a maximum diameter of 35 mm over 4 years. Finally, it was completely resected by open laparotomy and pathologically diagnosed as AH. Retroperitoneal hemangioma is extremely rare in adulthood and has been confirmed in only 1-3% of all retroperitoneal tumors. To the best of our knowledge, only 6 cases of para-aortic AH have been reported. The incidence of this variant is very low. However, AH may be included in the differential diagnosis when a slowly progressing heterogeneous mass appears in the para-aortic region that exhibits a CT-enhanced pattern similar to a typical cavernous hemangioma.

A Case of Castleman's Disease with a Marked Infiltration of IgG4-Positive Cells in the Renal Interstitium.

Multicentric Castleman's disease (MCD) is a benign lymphoproliferative disorder with heterogenous clinical symptoms, and involves systemic organs in addition to lymph nodes. Herein, we present the case of a 55-year-old man with MCD characterized by an extensive infiltration of IgG4+ plasma cells in the kidneys. The patient presented to our hospital with a high fever and diarrhea. On admission, laboratory analysis revealed anemia, renal dysfunction (eGFR 30 mL/min/1.73 m2), polyclonal gammopathy (IgG 7130 mg/dL), elevated serum IgG4 level (2130 mg/dL), and increased C-reactive protein (8.0 mg/dL). An enlargement of lymph nodes in the axillary, mediastinal, para-aortic, and inguinal regions was observed on abdominal computed tomography. Axillary lymph node biopsy revealed interfollicular expansion due to dense plasma cell infiltration. Renal biopsy demonstrated significant plasma cell infiltration into the tubulointerstitium. Immunohistochemical analysis showed a 40% IgG4-positive/IgG-positive plasma cell ratio, meeting the diagnostic criteria for an IgG4-related disease. Amyloid A deposition was observed along vessel walls, and immunofluorescence analysis indicated granular positivity of IgG and C3 along the glomerular capillary wall. Elevated levels of interleukin-6 (21 pg/mL) and vascular endothelial growth factor (VEGF; 1210 pg/mL) were noted. Based on these findings, and the histological finding of the lymph node biopsy, idiopathic MCD was diagnosed. Corticosteroid monotherapy was only partially effective. Subsequently, tocilizumab administration was initiated, leading to sustained remission, even after discontinuation of prednisolone. Due to the diverse responses to steroid therapy and the varying prognoses observed in MCD and IgG4-related disease, it is essential to carefully diagnose MCD by thoroughly assessing the organ distribution of the disease, its response to steroid therapy, and any additional pathological findings.

Sex Disparities in Applied Force on Maxillary Incisors Among Novices During Laryngoscopy Using a High-Fidelity Simulator: A Prospective Observational Study.

Endotracheal intubation (ETI) is a common and crucial intervention. Whether the performance of ETI differs according to the sex of the laryngoscopist remains unclear. The aim of this study was to assess sex disparities in markers of ETI performance among novices using a high-fidelity simulator. This prospective observational study was conducted from April 2017 to March 2019 in a public medical university. In total, 209 medical students (4th and 5th grade) without clinical ETI experience were recruited. Of the 209 students, 64 (30.6%) were female. The participants used either a Macintosh direct laryngoscope or C-MAC video laryngoscope in combination with a stylet or gum-elastic bougie to perform ETI on a high-fidelity simulator. The primary endpoint was the maximum force applied on the maxillary incisors during laryngoscopy. The secondary endpoint was the time to ETI. The implanted sensors in the simulator automatically quantified the force and time to ETI. The maximum force applied on the maxillary incisors was approximately 30% lower in the male than female group for all laryngoscopes and intubation aids examined (all P < 0.001). Similarly, the time to ETI was approximately 10% faster in the male than female group regardless of the types of laryngoscopes and intubation aids used (all P < 0.05). In this study, male sex was associated with a lower maximum force applied on the maxillary incisors during both direct and indirect laryngoscopy performed by novices. A clinical study focusing on sex differences in ETI performance is needed to validate our findings.

Severe acute interstitial nephritis induced by α-glucosidase inhibitor miglitol in an elderly patient with type 2 diabetic nephropathy.

A 79-year-old male patient with type 2 diabetic nephropathy and hypertension was admitted to our hospital because of acute kidney injury with significantly elevated serum creatinine (8.12 mg/dL) and urinary ß2-microglobulin (ß2MG, 31,748 µg/L) levels. α-Glucosidase inhibitor (α-GI) miglitol, started two weeks prior to presentation, was discontinued because drug-induced acute interstitial nephritis (AIN) was suspected. Renal biopsy revealed AIN and diabetic nephropathy. The drug-induced lymphocyte stimulation test for miglitol was also positive. After the discontinuation of miglitol, the urinary ß2MG levels decreased to the normal range. This case raises the possibility that α-GI miglitol can worsen the renal function in patients with underlying renal dysfunction.

Pediatric IgA-Dominant Infection-Related Glomerulonephritis.

The concept of infection-related glomerulonephritis (IRGN) has been introduced as adults diagnosed with glomerulonephritis often have coexisting active infections. Furthermore, IgA-dominant IRGN is associated with staphylococcal infections in adults with comorbidities, which often progress to end-stage renal disease. Little is known about IgA-dominant IRGN in children, and no consensus for a management strategy of this condition has been reached. We describe the case of a 9-year-old boy with IgA-dominant IRGN that was diagnosed using specific staining for nephritis-associated plasmin receptor (NAPlr)/plasmin activity and galactose-deficient IgA1 (Gd-IgA1), a marker of IgA nephropathy. The patient was successfully treated using a combination of prednisolone, mizoribine (an immunosuppressive drug), and lisinopril (an angiotensin-converting enzyme inhibitor) and three courses of methylprednisolone pulse therapy. The patient was admitted to our hospital with generalized edema, gross hematuria, proteinuria, hypertension, and renal dysfunction. Hypocomplementemia contributed to a diagnosis of IRGN, although the causative organism was unknown. A renal biopsy performed when the patient presented with nephrotic syndrome showed IgA deposition, positive staining for NAPlr, and negative staining for Gd-IgA1, in addition to findings consistent with IRGN, leading to a pathologic diagnosis of IgA-dominant IRGN. The histological staining for NAPlr/plasmin activity and Gd-IgA1, together with clinical symptoms, could be helpful for diagnosing IgA-dominant IRGN. Our findings indicate that otherwise healthy children can also develop IgA-dominant IRGN. Therefore, early diagnosis and aggressive treatment should be considered when IgA-dominant IRGN is suspected to avoid the possibility of incomplete recovery of renal function.

Attempted Suicide Is Independently Associated with Increased In-Hospital Mortality and Hospital Length of Stay among Injured Patients at Community Tertiary Hospital in Japan: A Retrospective Study with Propensity Score Matching Analysis.

Suicide is an increasingly important public healthcare concern worldwide. Studies examining the effect of attempted suicide on clinical outcomes among patients with trauma are scarce. We conducted a retrospective cohort study at a community emergency department in Japan. We included all severely injured patients with an Injury Severity Score > 15 from January 2002 to December 2021. The primary outcome measure was in-hospital mortality. The other outcome of interest was hospital length of stay. One-to-one propensity score matching was performed to compare these outcomes between suicide attempt and no suicide attempt groups. Of the 2714 eligible patients, 183 (6.7%) had trauma caused by a suicide attempt. In the propensity score-matched analysis with 139 pairs, the suicide attempt group showed a significant increase in-hospital mortality (20.9% vs. 37.4%; odds ratio 2.27; 95% confidence intervals 1.33-3.87) compared with the no suicide attempt group. Among survivors, the median hospital length of stay was significantly longer in the suicide attempt group than that in the no suicide attempt group (9 days vs. 12 days, p = 0.0076). Because of the unfavorable consequences and potential need for additional healthcare, increased attention should be paid to patients with trauma caused by a suicide attempt.

Repetitive abdominal pain in a reproductive-aged woman.

We report a young woman with ileocecal endometriosis who presented with repeated abdominal pain. Under hormonal effects, the endometrium may proliferate and cause bleeding in the bowel wall, leading to cyclical abdominal pain. When recurring abdominal pain is observed in reproductive-aged women, physicians should always be aware of gastrointestinal endometriosis.

Ultrasound-based upper limb muscle thickness is useful for screening low muscularity during intensive care unit admission: A retrospective study.

BACKGROUND & AIMS: Malnutrition is associated with poor outcomes. Muscle mass is an important malnutrition indicator included in Global Leadership Initiative on Malnutrition (GLIM) criteria. Although bioelectrical impedance analysis and dual-energy X-ray absorptiometry are common muscle mass assessment methods, they are unreliable during intensive care unit (ICU) admission due to the influence of dynamic fluid changes. We hypothesized that ultrasound-based upper limb muscle assessment would be useful for assessing muscularity at ICU admission. METHODS: We retrospectively analyzed prospectively obtained ultrasound data from patients admitted to an ICU. We excluded patients without computed tomography (CT) imaging of the third lumbar vertebra within 2 days of ICU admission. Primary outcomes were the diagnostic utility of ultrasound-based upper limb muscle thickness for assessing low muscularity by CT. Low muscularity was defined as a skeletal muscle index of 36.0 cm2/m2 for males and 29.0 cm2/m2 for females at the cross-sectional area of the third lumbar vertebrae. Secondary outcomes of this study included the relationships between upper limb muscle thickness and biceps brachii muscle cross-sectional area, quadriceps femoris thickness, rectus femoris cross-sectional area. RESULTS: Among 64 patients assessed by ultrasound, 52 had CT examination records and were included in the analysis. The mean age was 70 ± 13 years, and the mean body mass index was 23.3 ± 4.2 kg/m2. Upper limb muscle thickness had the discriminative power to assess low muscularity at an area under the curve of 0.77 (95% CI [confidence interval], 0.63-0.91); the cutoff value (26.8 cm) had 84.6% sensitivity and 66.7% specificity. The upper limb muscle index had the discriminative power to assess low muscularity at an area under the curve of 0.80 (95% CI, 0.68-0.93); the cutoff value (9.9 mm/m2) had 76.9% sensitivity and 71.8% specificity. Upper limb muscle thickness was correlated with upper limb muscle cross-sectional area, quadriceps femoris muscle thickness, rectus femoris muscle cross-sectional area (r = 0.39-0.76, p < 0.01, n = 52). CONCLUSIONS: Ultrasound-based upper limb muscle thickness assessments can screen for low muscularity upon ICU admission.

Gender Disparities in First Authorship at Three Medical Universities in an Area Affected by the Great East Japan Earthquake.

The Great East Japan Earthquake that occurred on March 11, 2011, was one of the largest natural disasters in modern times. Publication in medical journals is important aspects of the academic promotion process, and is thus important for all scientists. However, little is known about whether and how substantial natural disasters affect gender disparities in academic productivity in disaster-affected areas. We hypothesized that the Great East Japan Earthquake widened the existing disparities in scientific publishing between male and female researchers. To test this hypothesis, this retrospective observational study using existing databases was conducted. We extracted from the MEDLINE database all types of biomedical articles published from March 11, 2007, to March 11, 2015, by three medical universities in a disaster-affected area of Japan. Differences in the proportion of female first authorship during the 4 years before and after the Great East Japan Earthquake were compared. A total of 5,873 papers were analyzed. The proportion of female first authors significantly declined after the Great East Japan Earthquake (20.5% vs. 14.1%; odds ratio 0.64; 95% confidence interval 0.56-0.73). A similar trend was identified across all prespecified subgroups, including clinical department; original article; public medical university; and prestigious journal with impact factor >6. Reference data from two medical universities minimally affected by the Great East Japan Earthquake showed the opposite trend. These results collectively suggest that large natural disasters can reinforce existing gender disparities in first authorship in biomedicine.

Acute Interstitial Nephritis with Glomerular Capillary IgA Deposition Following SARS-CoV-2 mRNA Vaccination.

We herein report a case of acute kidney injury (AKI) presenting as acute interstitial nephritis (AIN) after the first dose of the BNT162b2 mRNA vaccine against coronavirus disease 2019 (COVID-19). A 69-year-old man with a history of diabetes and hypertension presented with AKI 4 days after receiving the vaccine. Despite the administration of methylprednisolone pulse treatment, his renal function worsened, which prompted us to initiate temporal hemodialysis. His renal function subsequently improved, and a renal biopsy confirmed AIN and glomerular capillary IgA deposition without apparent crescents. The clinical history and histological findings suggest a relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and AIN as a rare side effect.

Increased Interleukin-17-Producing γδT Cells in the Brain Exacerbate the Pathogenesis of Sepsis-Associated Encephalopathy and Sepsis-Induced Anxiety in Mice.

Overactivated microglia play a key role in sepsis-associated encephalopathy (SAE), although the involvement of T cells is unclear. γδT cells in the brain and meninges regulate normal fear responses via interleukin (IL)-17 in healthy mice. In our sepsis model, the mice showed exacerbated anxious behavior at 10 days post-induction (dpi). At 8 dpi, IL-17 mRNA was significantly upregulated in the brains of septic mice compared with those of control mice. Simultaneously, the number of γδT cells increased in the brains of septic mice in a severity-dependent manner. Additionally, IL-17-producing γδT cells, expressing both the C-X-C motif receptor (CXCR) 6 and the C-C motif receptor (CCR) 6, increased in mice brains, dependent on the severity of sepsis. The frequency of γδT cells in the meninges fluctuated similarly to that in the brain, peaking at 8 dpi of sepsis. Behavioral tests were performed on septic mice after the continuous administration of anti-γδTCR (α-γδTCR) or anti-IL-17A (α-IL-17A) antibodies to deplete the γδT cells and IL-17A, respectively. Compared with IgG-treated septic mice, α-γδTCR- and α-IL-17A-treated septic mice showed suppressed microglial activation and improvements in anxious behavior. These results suggested that CCR6+CXCR6+ IL-17-producing γδT cells in the brain and meninges promote the exacerbation of SAE and sepsis-induced psychological disorders in mice.

Impact of the coronavirus disease 2019 (COVID-19) pandemic on the operational efficiency of emergency medical services and its association with out-of-hospital cardiac arrest survival rates: A population-based cohort study in Kobe, Japan.

Aim: To identify whether the coronavirus disease 2019 (COVID-19) pandemic affects the operational efficiency of emergency medical services (EMS) and the survival rate of out-of-hospital cardiac arrest (OHCA) in prehospital settings. Methods: We conducted a population-based cohort study in Kobe, Japan, between March 1, 2020, and September 31, 2022. In study 1, the operational efficiency of EMS, such as the total out-of-service time for ambulances, the daily occupancy rate of EMS, and response time, was compared between the pandemic and nonpandemic periods. In study 2, the impacts of the changes in EMS operational efficiency were investigated among patients with OHCA, with 1-month survival as the primary outcome and return of spontaneous circulation, 24-h survival, 1-week survival, and favorable neurological outcomes as the secondary outcomes. Logistic regression analysis was conducted to identify the factors associated with survival among patients with OHCA. Results: The total out-of-service time, occupancy rate, and response time significantly increased during the pandemic period (p < 0.001). The response time during the pandemic period increased significantly per pandemic wave. Regarding OHCA outcomes, 1-month survival rates during the pandemic period significantly decreased compared with those during the nonpandemic period (pandemic 3.7% vs. nonpandemic 5.7%; p < 0.01). Similarly, 24-h survival (9.9% vs. 12.8%), and favorable neurological outcomes significantly decreased during the pandemic period. In the logistic regression analysis, response time was associated with lower OHCA survival in all outcomes (p < 0.05). Conclusion: The COVID-19 pandemic has been associated with reduced operational efficiency of EMS and decreased OHCA survival rates. Further research is required to improve the efficiency of EMS and OHCA survival rates.

Clinical utility of artificial intelligence assistance in histopathologic review of lymph node metastasis for gastric adenocarcinoma.

BACKGROUND: Advances in whole-slide image capture and computer image analyses using deep learning technologies have enabled the development of computer-assisted diagnostics in pathology. Herein, we built a deep learning algorithm to detect lymph node (LN) metastasis on whole-slide images of LNs retrieved from patients with gastric adenocarcinoma and evaluated its performance in clinical settings. METHODS: We randomly selected 18 patients with gastric adenocarcinoma who underwent surgery with curative intent and were positive for LN metastasis at Chiba University Hospital. A ResNet-152-based assistance system was established to detect LN metastases and to outline regions that are highly probable for metastasis in LN images. Reference standards comprising 70 LN images from two different institutions were reviewed by six pathologists with or without algorithm assistance, and their diagnostic performances were compared between the two settings. RESULTS: No statistically significant differences were observed between these two settings regarding sensitivity, review time, or confidence levels in classifying macrometastases, isolated tumor cells, and metastasis-negative. Meanwhile, the sensitivity for detecting micrometastases significantly improved with algorithm assistance, although the review time was significantly longer than that without assistance. Analysis of the algorithm's sensitivity in detecting metastasis in the reference standard indicated an area under the curve of 0.869, whereas that for the detection of micrometastases was 0.785. CONCLUSIONS: A wide variety of histological types in gastric adenocarcinoma could account for these relatively low performances; however, this level of algorithm performance could suffice to help pathologists improve diagnostic accuracy.

A case of eosinophilic pancreatitis in a patient with ulcerative colitis.

Eosinophilic pancreatitis (EP) is very rare and characterised by infiltration of eosinophils into the pancreatic parenchyma. A 40-year-old man was diagnosed with total-colitis-type ulcerative colitis at the age of 15 years. He was then diagnosed with steroid-dependent ulcerative colitis. He was given golimumab, which resulted in remission. Ten months after beginning golimumab, he was urgently hospitalised with a diagnosis of acute pancreatitis. Hence, endoscopic ultrasound-guided fine needle biopsy was performed to obtain a definitive diagnosis. Pathologically, abundant infiltration of eosinophils was observed in the edematous intralobular stroma of the pancreas. He was diagnosed with EP, and treated with corticosteroids.

Severe left kidney laceration after minor fall in a patient with lumbar spine scoliosis.

Background: The kidneys are one of the organs most commonly affected by blunt trauma; however, the anatomical variations that predispose kidney injury are poorly understood. Case Presentation: An 80-year-old Japanese woman with lumber scoliosis was brought to our hospital because of severe flank pain after a minor fall at home. Contrast-enhanced computed tomography showed a severe left kidney laceration at the level of an acute angle in the vertebral column caused by scoliosis. Extravasation of contrast medium from the left renal artery branches was also noted. Selective arterial embolization achieved hemostasis. The patient was transferred to a rehabilitation facility without sequelae. Conclusion: Patients with scoliosis could be at higher risk of severe kidney laceration because of intrusion of the vertebral column into the retroperitoneal space. Therefore, even after low-impact trauma, active exploration for kidney injury could be warranted in patients with spinal curvature disorders.

Long-Term Incidence and Timing of Splenic Pseudoaneurysm Formation after Blunt Splenic Injury: A Descriptive Study.

BACKGROUND: Nonoperative management (NOM) has become a standard strategy for hemodynamically stable patients with blunt splenic injury; however, delayed rupture of splenic pseudoaneurysm (SPA) is a serious complication of NOM. In medical literature, data regarding the long-term incidence of SPA are scarce, and the appropriate timing for performing follow-up contrast-enhanced computed tomography (CT) has not yet been reported. This study aimed to elucidate the long-term incidence and timing of SPA formation after blunt splenic injury in patients treated with NOM. METHODS: This descriptive study was conducted at a tertiary medical center in Japan. Patients with blunt splenic injury who were treated with NOM between April 2014 and August 2020 were included in the analysis. Included patients underwent repeated contrast-enhanced CT to detect SPA formation. The primary outcome was the cumulative incidence of delayed formation of SPA. We also evaluated differences in SPA formation between patients who received transcatheter arterial embolization (TAE; TAE group) and those who did not receive it (non-TAE group) on admission day. RESULTS: Among 49 patients with blunt splenic injury who were treated with NOM, 5 patients (10.2%) had delayed formation of SPA. All cases of SPA formation occurred within 15 days of injury. The incidence of SPA formation was not significantly different between the TAE and non-TAE groups (1/19 vs. 4/30, P = 0.67). CONCLUSIONS: SPA developed in 10% of patients within approximately 2 weeks after blunt splenic injury. Therefore, performing follow-up contrast-enhanced CT in this period after injury may be useful to evaluate delayed formation of SPA. Although our findings are novel, they should be confirmed through future studies with larger sample sizes.

Sepsis causes neutrophil infiltration in muscle leading to muscle atrophy and weakness in mice.

Background: Sepsis-induced muscle atrophy leads to prolonged physical dysfunction. Although the interaction of muscle atrophy and macrophage has been reported in sepsis, the role of neutrophils in muscle atrophy has not been thoroughly investigated. This study sought to investigate the long-term changes in muscle-localized neutrophils after sepsis induction and their possible role in sepsis. Methods: Sepsis was induced in seven-week-old male C57BL/6J mice 8-12 (cecal slurry [CS] model) via intraperitoneal injection of 1 mg/g cecal slurry. The percentage change in body weight and grip strength was evaluated. The tibialis anterior muscles were dissected for microscopic examination of the cross-sectional area of myofibers or Fluorescence-activated cell sorting (FACS) analysis of immune cells. These changes were evaluated in the following conditions: (1) Longitudinal change until day 61, (2) CS concentration-dependent change on day 14 at the low (0.3 mg/g), middle (1.0 mg/g), and high (2.0 mg/g) concentrations, and (3) CS mice on day 14 treated with an anti-Ly6G antibody that depletes neutrophils. Results: Body weight and grip strength were significantly lower in the CS model until day 61 (body weight: 123.1% ± 1.8% vs. 130.3% ± 2.5%, p = 0.04; grip strength: 104.5% ± 3.8% vs. 119.3% ± 5.3%, p = 0.04). Likewise, cross-sectional muscle area gradually decreased until day 61 from the CS induction (895.6 [606.0-1304.9] µm2 vs. 718.8 [536.2-937.0] µm2, p < 0.01). The number of muscle-localized neutrophils increased from 2.3 ± 0.6 cell/mg on day 0 to 22.2 ± 13.0 cell/mg on day 14, and decreased thereafter. In terms of CS concentration-dependent change, cross-sectional area was smaller (484.4 ± 221.2 vs. 825.8 ± 436.2 µm2 [p < 0.001]) and grip strength was lower (71.4% ± 12.8% vs. 116.3% ± 7.4%, p = 0.01) in the CS High group compared with the control, with increased neutrophils (p = 0.03). Ly6G-depleted mice demonstrated significant increase of muscle cross-sectional area and grip strength compared with control mice (p < 0.01). Conclusions: Sepsis causes infiltration of neutrophils in muscles, leading to muscle atrophy and weakness. Depletion of neutrophils in muscle reverses sepsis-induced muscle atrophy and weakness. These results suggest that neutrophils may play a critical role in sepsis-induced muscle atrophy and weakness.

Current practice and barriers in the implementation of ultrasound-based assessment of muscle mass in Japan: A nationwide, web-based cross-sectional study.

Muscle mass is an important factor for surviving an illness. Ultrasound has gained increased attention as a muscle mass assessment method because of its noninvasiveness and portability. However, data on the frequency of ultrasound-based muscle mass assessment are limited, and there are some barriers to its implementation. Hence, a web-based cross-sectional survey was conducted on healthcare providers in Japan, which comprised four parts: 1) participant characteristics; 2) general muscle mass assessment; 3) ultrasound-based muscle mass assessment; and 4) the necessity of, interest in, and barriers to its implementation. Necessity and interest were assessed using an 11-point Likert scale, whereas barriers were assessed using a 5-point Likert scale, in which "Strongly agree" and "Agree" were counted for the analysis. Of the 1,058 responders, 1,026 participants, comprising 282 physicians, 489 physical therapists, 84 occupational therapists, 120 nurses, and 51 dieticians, were included in the analysis. In total, 93% of the participants were familiar with general muscle mass assessment, and 64% had conducted it. Ultrasound-based muscle mass assessment was performed by 21% of the participants. Necessity and interest scored 7 (6-8) and 8 (7-10), respectively for ultrasound-based muscle mass assessment. The barriers to its implementation included lack of relevant education (84%), limited staff (61%), and absence of fixed protocol (61%). Regardless of the necessity of and interest in ultrasound-based muscle mass assessment, it was only conducted by one-fifth of the healthcare providers, and the most important barrier to its implementation was lack of education.