Consideration of the diameter of superficial temporal arteries related to filler injections in the temporal region.

BACKGROUND: The concavity of the temple due to adipose tissue atrophy from aging accentuates the zygomatic arch and lateral orbital rim, leading to an aged appearance. The use of hyaluronic acid filler in the temporal region has gained popularity due to its procedural simplicity and consistent outcomes. OBJECTIVE: To evaluate the safety of administering hyaluronic acid filler in the temporal region concerning the frontal branch of the superficial temporal artery, which is at risk of injury. METHODS: Empirical observations were conducted on the internal diameter of the frontal branch of the superficial temporal artery, a critical anatomical site for potential injury. RESULTS: A significant proportion of the artery segments exhibited an internal diameter below 1 mm. Given that the outer diameter of an 18-gauge cannula is 1.27 mm, this method can be considered a relatively secure approach for enhancing the temporal region. CONCLUSION: The use of an 18-gauge cannula for hyaluronic acid filler administration in the temporal region appears to be a safe and effective method, with the potential risk to the frontal branch of the superficial temporal artery being minimal.

Piriformis syndrome as an overlooked cause of pain in a patient with axial spondyloarthritis: a case report.

Piriformis syndrome is a neuromuscular disorder characterized by hip, buttock, and leg pain. Axial spondyloarthritis is a rheumatic disease primarily affecting the sacroiliac joint and the spine. Due to their anatomical proximity, the potential relationship between piriformis syndrome and sacroiliitis has been discussed for some time. However, literature review revealed that there is no study on piriformis syndrome in individuals with axial spondyloarthritis. Here, we present the case of a 30-year-old female with axial spondyloarthritis who developed severe low back, hip, and buttock pain that persisted despite initial treatment for axial spondyloarthritis. We first re-evaluated her condition through physical examination, magnetic resonance imaging, and an injection test for piriformis syndrome. Following a comprehensive assessment, the patient was diagnosed with both axial spondyloarthritis and piriformis syndrome. Subsequently, a tailored treatment plan was devised, addressing both conditions, and after a 3-month course of treatment, we obtained significant reduction in pain of the patient. This is the first case report in literature, where we used injection test to confirm the diagnosis of the piriformis syndrome in a patient with axial spondyloarthritis. We therefore strongly advocate considering piriformis syndrome as a potential etiology for pain in individuals with axial spondyloarthritis consistently. This recognition is important as piriformis syndrome does not respond adequately to non-steroidal anti-inflammatory drugs and may lead to unnecessary use of biological disease-modifying antirheumatic drugs. Timely identification and intervention are imperative in ensuring optimal patient care.

Ultrasonography is an effective tool for breast cancer screening in individuals with severe motor and intellectual disabilities.

BACKGROUND: Individuals with severe motor and intellectual disabilities have become an aging population, and high cancer morbidity and mortality are critical issues affecting their survival. Cancer screening is a crucial method of resolving this issue; however, a suitable screening method for them has not been established. METHODS: We used ultrasonography alone and performed breast cancer screening for women over 30 years old in our facility from 2016 to 2023. We observed the outcomes and calculated the recall/detection rate in this screening. RESULTS: Three cases among 379 tested positive in this screening, all of which underwent radical surgery. They are alive and well without relapse present. We detected these breast cancer cases with a low recall rate. CONCLUSION: We were able to successfully detect breast cancer cases using ultrasonography alone. Ultrasonography is an effective and feasible tool for breast cancer screening in individuals with severe motor and intellectual disabilities.

Duplex ultrasound and pedal acceleration time as tools to evaluate foot perfusion: a literature review.

Currently, the standard non-invasive test for diagnosing Peripheral Arterial Disease is the Ankle-Brachial Index. However, this test becomes unfeasible in a certain population. New evidence proposes the pedal acceleration time, an ultrasound index, as an alternative test. An integrative bibliographic review was carried out between June 3, 2022 and January 8, 2023, to investigate this new index as a tool to assess foot perfusion. Papers published in English, Portuguese, or Spanish between 2012 and 2022 were searched on PubMed, Google Scholar, and Scielo, using the keywords "Peripheral Arterial Disease" AND "Acceleration Time" AND (Pedal OR Plantar). Research that didn't assess foot perfusion using the methods of interest or did not present human data and also case series or reports were excluded. Seven out of the sixty-six articles identified in the searches were selected for the review, all of which had notable methodological limitations. Pedal acceleration time seems to be able to diagnose and stratify and may reflect prognosis.

Atualmente, o teste não invasivo padrão para diagnosticar a doença arterial periférica é o índice tornozelo-braquial, porém, em uma determinada população, este torna-se inviável. Novas evidências propõem o tempo de aceleração plantar, que é um índice ultrassonográfico, como alternativa. Para investigá-lo no contexto do estudo da perfusão do pé, uma revisão bibliográfica integrativa foi realizada entre 03/06/2022 e 08/01/2023. Artigos em inglês, português ou espanhol, publicados entre 2012 e 2022 foram pesquisados através das ferramentas PubMed, Google Scholar e SciELO, com as palavras-chave "Peripheral Arterial Disease" AND "Acceleration Time" AND (Pedal OR Plantar). Pesquisas que não avaliaram a perfusão do pé pelos métodos de interesse, sem dados em humanos e relatos ou séries de casos, foram excluídos. Dos 66 artigos, 7 foram selecionados; todos com notáveis limitações metodológicas. O tempo de aceleração plantar aparenta ser capaz de diagnosticar, estratificar e prognosticar os doentes.

Epidermoid cyst of the testis: A report of three cases.

Testicular epidermoid cysts have characteristic findings. Testicular tumor markers are negative in patients with epidermoid cysts. Clear margins and sole and small testicular tumors (20 mm or less) suggest the possibility of epidermoid cyst. Testicular-sparing surgery with intraoperative frozen section examination should be performed when suspecting epidermoid cysts. Testicular epidermoid cysts are rare tumors that account for 1% of all testicular tumors and are often clinically misdiagnosed as malignant lesions. We report three cases of epidermoid cysts. The chief manifestations were scrotal induration in two patients and pruritus scrotum in one. The median age of the patients was 23 years (18-30). All tumors were determined to be sole lesions (<20 mm in diameter). Testing for tumor markers in all patients revealed negative results. We could not rule out malignancy; hence, we performed high inguinal orchiectomy in all cases. Histologically, the inner walls of the cysts were lined with stratified squamous epithelium; their contents were keratinized. All patients were diagnosed with epidermoid cysts.

Ultrasonographic Contrast and Therapeutic Effects of Hydrogen Peroxide-Responsive Nanoparticles in a Rat Model with Sciatic Neuritis.

Purpose: Peripheral nerve damage lacks an appropriate diagnosis consistent with the patient's symptoms, despite expensive magnetic resonance imaging or electrodiagnostic assessments, which cause discomfort. Ultrasonography is valuable for diagnosing and treating nerve lesions; however, it is unsuitable for detecting small lesions. Poly(vanillin-oxalate) (PVO) nanoparticles are prepared from vanillin, a phytochemical with antioxidant and anti-inflammatory properties. Previously, PVO nanoparticles were cleaved by H2O2 to release vanillin, exert therapeutic efficacy, and generate CO2 to increase ultrasound contrast. However, the role of PVO nanoparticles in peripheral nerve lesion models is still unknown. Herein, we aimed to determine whether PVO nanoparticles can function as contrast and therapeutic agents for nerve lesions. Methods: To induce sciatic neuritis, rats were administered a perineural injection of carrageenan using a nerve stimulator under ultrasonographic guidance, and PVO nanoparticles were injected perineurally to evaluate ultrasonographic contrast and therapeutic effects. Reverse transcription-quantitative PCR was performed to detect mRNA levels of pro-inflammatory cytokines, ie, tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2. Results: In the rat model of sciatic neuritis, PVO nanoparticles generated CO2 bubbles to increase ultrasonographic contrast, and a single perineural injection of PVO nanoparticles suppressed the expression of tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2, reduced the expression of F4/80, and increased the expression of GAP43. Conclusion: The results of the current study suggest that PVO nanoparticles could be developed as ultrasonographic contrast agents and therapeutic agents for nerve lesions.

Ultrasound-guided arthrocentesis for condylar head fracture: a technical report.

OBJECTIVES: Double puncture arthrocentesis (DPA) of the temporomandibular joint (TMD) is considered an effective preservative option for managing mandibular condylar head fractures. However, the procedure is commonly performed by a traditional "blind" method using anatomical characteristics. In the present study, an ultrasonography (US) device was applied for the treatment of a case with a fractured mandibular condyle. METHODS: A 79-year-old female was diagnosed right side condylar head fracture complaining pain of right TMD and reduced mouth opening range: inter-incisor distance of 20 mm. Since the fracture position was high and inoperable, the decision was made to perform DPA of the TMD. The US probe was positioned parallel and slightly oblique to the major axis of the mandibular ramus. Both the posterior and anterior insertions into the joint space were performed according to the axis mentioned above, which enabled the operator to visualize the entirety of the needle. RESULTS: The device offered safety and ensured accuracy by providing real-time visual aid to the surgeon. The procedure provided an early increase in the inter-incisor distance (31 mm) and pain relief. CONCLUSIONS: Hence, for the preservative treatment of mandibular condylar head fractures, based on the present study, we recommend US-guided arthrocentesis as a safe, feasible, and effective therapeutic option instead of the conventional "blind" method.

Unveiling the potential of strain elastography in perihilar cholangiocarcinoma biopsies.

PURPOSE: This study was conducted to investigate the effectiveness of strain elastography in guiding precise and sufficient tissue sampling for perihilar cholangiocarcinoma (CCA) biopsies. METHODS: Our retrospective analysis included 23 liver biopsies conducted between March 2019 and July 2022 for suspected perihilar CCA. An experienced radiologist performed the biopsies via an ultrasound machine with elastography configuration. Tissue stiffness color maps were used for guiding when the biopsies were performed. Strain index value calculations were made by radiologists on recorded images. RESULTS: Patient demographics revealed a mean age of 65.17 ± 9.25 years, with a gender distribution of six females and 17 males. Gray-scale examinations unveiled diverse echogenic characteristics in liver lesions. Elastography-guided biopsies demonstrated no need for repeats, while gray-scale biopsies necessitated re-biopsy in four patients, resulting in cholangiocarcinoma diagnosis (P = 0.037). Strain index values showcased strong inter- and intra-observer agreements (P < 0.001). Notably, no post-biopsy complications emerged in either study group. CONCLUSION: The diagnostic advantage of elastography, particularly in enhancing accuracy in challenging isoechoic lesions, was demonstrated, although the substantial overlap between strain index values of benign and malignant liver masses limits clinical usefulness of this technique.

Evaluation of the thickness of masticatory muscles in patients with chronic periodontitis by ultrasonography.

OBJECTIVES: Periodontitis is one of the most common chronic inflammatory diseases. It causes changes in the biting abilities of individuals. However, periodontal treatment has positive effects on masticatory function. The aim of this study is to determine the effect of periodontitis and periodontal treatment on masticatory abilities by measuring masseter and temporal muscle thicknesses with ultrasonography before and after periodontal treatment in chronic periodontitis patients. METHODS: The patients included in the study were determined by clinical and radiological examination. The thickness of the masseter and temporal muscles of the patients were measured by ultrasonography. Periodontal measurements and treatments of the patients were completed by a single physician. IBM SPSS 20.0 (IBM Corp., Armonk, NY) statistical program was used for statistical analysis. RESULTS: A statistically significant difference was found between the values of periodontal measurements before and after treatment (p<0.05). In the ultrasonography measurements of the thickness of masseter and anterior temporal muscles, a statistically significant increase was observed in both rest and contraction values at all time intervals (p<0.05). Muscle thicknesses of male patients were higher than female patients. CONCLUSIONS: Periodontitis negatively affects the masticatory performance of individuals. Chronic periodontitis patients should be referred for periodontal treatment without wasting time.

Echo-intensity characterization at implant sites and novel diagnostic ultrasonographic markers for peri-implantitis.

AIM: To apply high-frequency ultrasound (HFUS) echo intensity for characterizing peri-implant tissues at healthy and diseased sites and to investigate the possible ultrasonographic markers of health versus disease. MATERIALS AND METHODS: Sixty patients presenting 60 implants diagnosed as healthy (N = 30) and peri-implantitis (N = 30) were assessed with HFUS. HFUS scans were imported into a software where first-order greyscale outcomes [i.e., mean echo intensity (EI)] and second-order greyscale outcomes were assessed. Other ultrasonographic outcomes of interest involved the vertical extension of the hypoechoic supracrestal area (HSA), soft-tissue area (STA) and buccal bone dehiscence (BBD), among others. RESULTS: HFUS EI mean values obtained from peri-implant soft tissue at healthy and diseased sites were 122.9 ± 19.7 and 107.9 ± 24.7 grey levels (GL); p = .02, respectively. All the diseased sites showed the appearance of an HSA that was not present in healthy implants (area under the curve = 1). The proportion of HSA/STA was 37.9% ± 14.8%. Regression analysis showed that EI of the peri-implant soft tissue was significantly different between healthy and peri-implantitis sites (odds ratio 0.97 [95% confidence interval: 0.94-0.99], p = .019). CONCLUSIONS: HFUS EI characterization of peri-implant tissues shows a significant difference between healthy and diseased sites. HFUS EI and the presence/absence of an HSA may be valid diagnostic ultrasonographic markers to discriminate peri-implant health status.

Defining tibial anterior muscle morphology in first-ever chronic stroke patients using three-dimensional freehand ultrasound.

BACKGROUND: Drop foot is common post-stroke, elevating fall risks and mobility limitations. It is caused by weakness and lack of control of the tibialis anterior muscle (TA), for which various rehabilitation treatments are used. A reliable objective estimate of changes in TA muscle morphology and composition can enhance treatment optimization. OBJECTIVES: We aimed to ascertain 3D freehand ultrasound (3DfUS) reliability in measuring TA muscle volume, length, and echo intensity in stroke patients and healthy controls and its validity by comparing these features across legs, between patients and controls, and between clinical subgroups (i.e. patients with and without ankle contracture, spastic muscle overactivity, and foot dorsiflexor paresis). METHODS: We included 9 stroke patients and 9 healthy controls to define reliability and 26 stroke patients and 28 healthy controls to define validity. For reliability, data were collected and processed by 2 different operators and processors. For inter- and intra-rater reliability, intra-class correlation coefficient (ICC) and standard error of measurement (SEM) were used. For validity, Wilcoxon-Signed-Ranked and Mann-Whitney U tests were used for comparisons between groups and subgroups. RESULTS: All measurements showed good to excellent inter- and intra-rater reliability (ICC: 0.816 to 0.997, SEM: 0.5% to 7.8%). Comparison analyses revealed no differences in muscle features among legs, groups, or subgroups. CONCLUSION: While the 3DfUS is a reliable method to define TA morphology and composition, its clinical validity needs further investigation into factors influencing muscle property changes across various age groups and post-stroke time points. MESH TERMS: Stroke; Skeletal muscle morphology; muscle composition; 3D freehand ultrasonography, Anterior Tibial Muscle.

Ultrasonography-Based Quantitative Evaluation of Second Metatarsophalangeal Joint Instability in Female Patients With Hallux Valgus.

BACKGROUND: Patients with moderate to severe hallux valgus (HV) sometimes exhibit second metatarsophalangeal (MTP) joint dislocation. Second MTP joint instability due to plantar plate (PP) injury has been suggested as one of the causes. However, there have been no reports that quantitatively evaluate this instability. This study aimed to evaluate second MTP joint instability in patients with HV without dislocation via ultrasonography and investigate its relationship with the presence of PP injury or foot form. METHODS: Between May 2018 and July 2023, symptomatic female patients with HV without any lesser toe deformity were included in this study. Second MTP joint instability was defined as the dorsal displacement ratio (DDR) of the passively subluxated proximal phalangeal articular surface on the metatarsal head articular surface. The presence of PP injury was assessed using ultrasonography. Foot "form" was determined by measuring standard foot bony angles on weight-bearing foot-ankle radiographs. The relationship between DDR or PP injury and radiographic measurements was investigated. RESULTS: Sixty-four patients (100 feet) were included. The average DDR of the second MTP joint in patients with HV without dislocation was 35.7%. There was an increase in the probability of PP injury, above a cutoff DDR value r of 35.4% (area under the curve = 0.712). The sensitivity, specificity, positive predictive value, and negative predictive value for the presence of PP injury based on this cutoff level were 63.9%, 74.4%, 79.6%, and 56.9%, respectively. Metatarsalgia was reported in 21 feet (21.0%), of which 15 feet (71.4%) showed PP injury. An increase in DDR was weakly associated with increased metatarsus adductus angle and decreased second metatarsal height. CONCLUSION: In female patients with HV without second MTP dislocation, we found ultrasonographic evidence of second MTP plantar plate injury and joint instability to be a relatively common finding with a high prevalence in those with localized metatarsalgia. LEVEL OF EVIDENCE: Level II, development of diagnostic criteria based on consecutive patients.

The automatic activity of abdominal muscles during stable and unstable standing postural tasks in older adults with and without low back pain- A cross-sectional study.

BACKGROUND: The postural control and abdominal muscles' automatic activity were found to be impaired in subjects with low back pain (LBP) during static activities. However, the studies are predominantly conducted on younger adults and a limited number of studies have evaluated abdominal muscles' automatic activity during dynamic standing activities in subjects with LBP. The present study investigated the automatic activity of abdominal muscles during stable and unstable standing postural tasks in older adults with and without LBP. METHODS: Twenty subjects with and 20 subjects without LBP were included. The thickness of the transversus abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles was measured during rest (in supine), static, and dynamic standing postural tasks. To estimate automatic muscle activity, each muscle's thickness during a standing task was normalized to its thickness during the rest. Standing postural tasks were performed using the Biodex Balance System. RESULTS: The mixed-model analysis of variance revealed that task dynamicity significantly affected thickness change only in the TrA muscle (P = 0.02), but the main effect for the group and the interaction were not significantly different (P > 0.05). There were no significant main effects of the group, task dynamicity, or their interaction for the IO and EO muscles (P > 0.05). During dynamic standing, only the TrA muscle in the control group showed greater thickness changes than during the static standing task (P < 0.05). CONCLUSIONS: Standing on a dynamic level increased the automatic activity of the TrA muscle in participants without LBP compared to standing on a static level. Further research is required to investigate the effects of TrA muscle training during standing on dynamic surfaces for the treatment of older adults with LBP.

Teaching Medical Students Rapid Ultrasound for shock and hypotension (RUSH): learning outcomes and clinical performance in a proof-of-concept study.

BACKGROUND: Point-of-care ultrasound (POCUS) is a critical diagnostic tool in various medical settings, yet its instruction in medical education is inconsistent. The Rapid Ultrasound for Shock and Hypotension (RUSH) protocol is a comprehensive diagnostic tool, but its complexity poses challenges for teaching and learning. This study evaluates the effectiveness of a single-day training in RUSH for medical students by assessing their performance in clinical scenarios. METHODS: In this prospective single-center observational proof-of-concept study, 16 medical students from Saarland University Medical Center underwent a single-day training in RUSH, followed by evaluations in clinical settings and on a high-fidelity simulator. Performance was assessed using a standardized scoring tool and time to complete the RUSH exam. Knowledge gain was measured with pre- and post-training written exams, and diagnostic performance was evaluated with an objective structured clinical examination (OSCE). RESULTS: Students demonstrated high performance in RUSH exam views across patients (median performance: 85-87%) and improved scanning times, although not statistically significant. They performed better on simulators than on live patients. Written exam scores significantly improved post-training, suggesting a gain in theoretical knowledge. However, more than a third of students could not complete the RUSH exam within five minutes on live patients. CONCLUSIONS: Single-day RUSH training improved medical students' theoretical knowledge and simulator performance but translating these skills to clinical settings proved challenging. The findings suggest that while short-term training can be beneficial, it may not suffice for clinical proficiency. This study underscores the need for structured and possibly longitudinal training programs to ensure skill retention and clinical applicability.

Screening of Undiagnosed Increased Lateral Ankle Laxity Using Stress Ultrasonography.

Background: Some patients with lateral ankle sprain (LAS) will experience chronic lateral ankle instability (CLAI). However, not all of those with residual increased lateral ankle laxity (ILAL) become symptomatic. There is a lack of evidence regarding the prevalence of undiagnosed ILAL in the general population. Purpose: To evaluate the prevalence of undiagnosed ILAL with the use of stress ultrasonography (US) and to investigate the percentage of ankle sprain copers (ASCs) with ILAL. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The anterior talofibular ligament (ATFL) lengths in college students without diagnosis of CLAI were measured consecutively in stress and nonstress positions. The ATFL ratio was calculated as an indicator of lateral ankle laxity according to a previously reported method. The manual anterior drawer test was also performed. The Cumberland Ankle Instability Tool (CAIT) and Ankle Instability Instrument (AII) were used to assess subjective impairments related to CLAI. The correlation between the ATFL ratio and CAIT score was evaluated. Results: A total of 207 ankles from 106 participants (mean age, 23.9 ± 2.2 years; male/female, 64/42) were included. Overall, 38 participants (35.8%; 50 ankles [24.2%]) were classified as having undiagnosed ILAL. Of the ankles with no history of LAS, 8% showed ILAL. Overall, 53 participants (50%) had a history of LAS and were all classified as ASCs. Of the 82 ankles from these ASCs, 40 (48.8%) were regarded as having undiagnosed ILAL. There was no correlation between the ATFL ratio and CAIT scores (r = -0.09, P = .414). Conclusion: The prevalence of undiagnosed ILAL by stress US screening was approximately one-third in young adults. In this study, 48.8% of the ankles from ASCs showed ILAL.

Optimal examination for traumatic nerve/muscle injuries in earthquake survivors: a retrospective observational study.

Background: Physiatrists are facing with survivors from disasters in both the acute and chronic phases of muscle and nerve injuries. Similar to many other clinical conditions, neuromusculoskeletal ultrasound can play a key role in the management of such cases (with various muscle/nerve injuries) as well. Accordingly, in this article, a recent single-center experience after the Turkey-Syria earthquake will be rendered. Methods: Ultrasound examinations were performed for various nerve/muscle lesions in 52 earthquake victims referred from different cities. Demographic features, type of injuries, and applied treatment procedures as well as detailed ultrasonographic findings are illustrated. Results: Of the 52 patients, 19 had incomplete peripheral nerve lesions of the brachial plexus (n=4), lumbosacral plexus (n=1), and upper and lower limbs (n=14). Conclusion: The ultrasonographic approach during disaster relief is paramount as regards subacute and chronic phases of rehabilitation. Considering technological advances (e.g., portable machines), the use of on-site ultrasound examination in the (very) early phases of disaster response also needs to be on the agenda of medical personnel.

Clinical Analysis of 76 Cases of Second Branchial Cleft Fistula.

Objective: To provide the experience of diagnosis and treatment of second branchial cleft fistula in children. Methods: The clinical data of 76 children with second branchial cleft fistulas admitted to Beijing Children's Hospital affiliated with Capital Medical University from January 2016 to December 2020 were retrospectively analyzed. All patients underwent cervical ultrasonography and resection of the second branchial cleft fistula, and their clinical manifestations, surgical methods, complications, recurrence condition, and lesion appearance of the patients were analyzed. Results: Among the 76 cases, the lesions of 43 cases were on the right side, 20 were on the left side, and 13 were bilateral, for a total of 89 lesions. There were 49 type I lesions, 28 type II lesions, 8 type III lesions, and 4 type IV lesions. Type I and type II cases underwent complete excision of the fistula through a small incision in the neck; 2 cases of type III branchial cleft fistulas were treated with trapezoidal incision; 2 cases of type III branchial cleft fistulas underwent single transverse incisions; single small incision-assisted endoscopic resection was adopted in 4 cases of type III and 4 cases of type IV branchial cleft fistulas. During the follow-up period of 6 to 60 months, only 3 cases developed postoperative infection, the others had no postoperative complications, and no cases had recurrence during postoperative follow-up. Conclusion: The incision of the second branchial fistula should be selected according to imaging examination to achieve removal of the fistula while maintaining esthetics.

Point of care ultrasonography as the new "Laennec Sthetoscope".

Point of care ultrasonography (POCUS) has evolved to become the fifth pillar of the conventional physical examination, and use of POCUS protocols have significantly decreased procedure complications and time to diagnose. However, lack of experience in POCUS by preceptors in medical schools and nephrology residency programs are significant barriers to implement a broader use. In rural and low-income areas POCUS may have a transformative effect on health care management.

Development and validation of a clinical and ultrasound features-based nomogram for preoperative differentiation of renal urothelial carcinoma and central renal cell carcinoma.

PURPOSE: This study aimed to develop and validate an ultrasound (US)-based nomogram for the preoperative differentiation of renal urothelial carcinoma (rUC) from central renal cell carcinoma (c-RCC). METHODS: Clinical data and US images of 655 patients with 655 histologically confirmed malignant renal tumors (521 c-RCCs and 134 rUCs) were collected and divided into training (n = 455) and validation (n = 200) cohorts according to examination dates. Conventional US and contrast-enhanced US (CEUS) tumor features were analyzed to determine those that could discriminate rUC from c-RCC. Least absolute shrinkage and selection operator regression was applied to screen clinical and US features for the differentiation of rUC from c-RCC. Using multivariate logistic regression analysis, a diagnostic model of rUC was constructed and visualized as a nomogram. The diagnostic model's performance was assessed in the training and validation cohorts by calculating the area under the receiver operating characteristic curve (AUC) and calibration plot. Decision curve analysis (DCA) was used to assess the clinical usefulness of the US-based nomogram. RESULTS: Seven features of both clinical features and ultrasound imaging were selected to build the diagnostic model. The nomogram achieved favorable discrimination in the training (AUC = 0.996, 95% CI: 0.993-0.999) and validation (AUC = 0.995, 95% CI: 0.974, 1.000) cohorts, and good calibration (Brier scores: 0.019 and 0.016, respectively). DCA demonstrated the clinical usefulness of the US-based nomogram. CONCLUSION: A noninvasive clinical and US-based nomogram combining conventional US and CEUS features possesses good predictive value for differentiating rUC from c-RCC.