{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:38:43Z","timestamp":1787027923093,"version":"build-2736575974"},"reference-count":32,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,10,28]],"date-time":"2022-10-28T00:00:00Z","timestamp":1666915200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background: There is little consensus on ultrasound (US) normative values of cross-sectional area of median nerve (MN-CSA) in carpal tunnel syndrome (CTS) because of its dependency on anthropometric parameters. We aim to propose a novel anthropometric-independent US parameter: MN-CSA\/flexor radialis carpi CSA (FCR-CSA) ratio (\u201cNerve Tendon Ratio\u201d, NTR), in the diagnosis of clinically and electrodiagnostic (EDS)-defined CTS. Methods: 74 wrists of 49 patients with clinically defined CTS underwent EDS (scored by the 1\u20135 Padua Scale of electrophysiological severity, PS) and US of carpal tunnel with measurement of MN-CSA (at the carpal tunnel inlet), FCR-CSA (over scaphoid tubercle) and its ratio (NTR, expressed as a percentage). US normality values and intra-operator agreement were assessed in 33 healthy volunteers. Results: In controls, the mean MN-CSA was 5.81 mm2, NTR 64.2%. In 74 clinical CTS, the mean MN-CSA was 12.1 mm2, NTR 117%. In severe CTS (PS &gt; 3), the mean MN-CSA was 15.9 mm2, NTR 148%. In CTS, both MN-CSA and NTR correlated with sensitive conduction velocity (SCV) (p &lt; 0.001), distal motor latency (DML) (p &lt; 0.001) and PS (p &lt; 0.001), with a slight superiority of NTR vs. MN-CSA when controlled for height, wrist circumference and weight. In CTS filtered for anthropometric extremes, only NTR maintained a correlation with SCV (p = 0.023), DML (p = 0.016) and PS (p = 0.009). Diagnostic cut-offs were obtained with a binomial regression analysis. In those patients with a clinical diagnosis of CTS, the cut-off of MN-CSA (AUROC: 0.983) was 8 mm2 (9 mm2 with highest positive predictive value, PPV), while for NTR (AUROC: 0.987), the cut-off was 83% (100% with highest PPV). In patients with EDS findings of severe CTS (PS &gt; 3), the MN-CSA (AUROC: 0.876) cut-off was 12.3 mm2 (15.3 mm2 with highest PPV), while for NTR (AUROC: 0.858) it was 116.2% (146.0% with highest PPV). Conclusions: NTR can be simply and quickly calculated, and it can be used in anthropometric extremes.<\/jats:p>","DOI":"10.3390\/diagnostics12112621","type":"journal-article","created":{"date-parts":[[2022,10,29]],"date-time":"2022-10-29T23:45:00Z","timestamp":1667087100000},"page":"2621","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["A Novel Ultrasonographic Anthropometric-Independent Measurement of Median Nerve Swelling in Carpal Tunnel Syndrome: The \u201cNerve\/Tendon Ratio\u201d (NTR)"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2667-4866","authenticated-orcid":false,"given":"Paolo","family":"Falsetti","sequence":"first","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3974-6606","authenticated-orcid":false,"given":"Edoardo","family":"Conticini","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caterina","family":"Baldi","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emilio","family":"D\u2019Ignazio","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suhel Gabriele","family":"Al Khayyat","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Bardelli","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6658-1037","authenticated-orcid":false,"given":"Stefano","family":"Gentileschi","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roberto","family":"D\u2019Alessandro","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2368-5722","authenticated-orcid":false,"given":"Miriana","family":"D\u2019Alessandro","sequence":"additional","affiliation":[{"name":"Unit of Respiratory Diseases and Lung Transplantation, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caterina","family":"Acciai","sequence":"additional","affiliation":[{"name":"Neurorehabilitation Unit, San Donato Hospital, 52100 Arezzo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4862-7107","authenticated-orcid":false,"given":"Federica","family":"Ginanneschi","sequence":"additional","affiliation":[{"name":"Neurology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7352-1275","authenticated-orcid":false,"given":"Luca","family":"Cantarini","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bruno","family":"Frediani","sequence":"additional","affiliation":[{"name":"Rheumatology Unit, Department of Medical, Surgical Sciences and Neurosciences, University Hospital of Siena, 53100 Siena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,10,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.clinph.2021.12.012","article-title":"Expert consensus on the combined investigation of carpal tunnel syndrome with electrodiagnostic tests and neuromuscular ultrasound","volume":"135","author":"Pelosi","year":"2022","journal-title":"Clin. Neurophysiol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Yoshii, Y., Zhao, C., and Amadio, P.C. (2020). Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome. Diagnostics, 10.","DOI":"10.3390\/diagnostics10080596"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1177\/1558944718821417","article-title":"Comparing Diagnostic and Treatment Recommendations of Carpal Tunnel Syndrome Available on the Internet With AAOS Clinical Practice Guidelines","volume":"15","author":"Steimle","year":"2020","journal-title":"Hand"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/j.jht.2021.04.014","article-title":"The role of diagnostic ultrasound in the examination of carpal tunnel syndrome: An update and systematic review","volume":"35","author":"Erickson","year":"2022","journal-title":"J. Hand Ther."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1002\/mus.10227","article-title":"Sonography in the diagnosis of carpal tunnel syndrome: A critical review of the literature","volume":"27","author":"Beekman","year":"2003","journal-title":"Muscle Nerve"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1002\/art.23317","article-title":"Diagnostic utility of ultrasonography versus nerve conduction studies in mild carpal tunnel syndrome","volume":"59","author":"Mondelli","year":"2008","journal-title":"Arthritis Rheum."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"993","DOI":"10.7863\/ultra.16.05019","article-title":"Sonography of Carpal Tunnel Syndrome According to Pathophysiologic Type: Conduction Block Versus Axonal Degeneration","volume":"36","author":"Moon","year":"2017","journal-title":"J. Ultrasound Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1121","DOI":"10.1016\/j.ultrasmedbio.2012.02.026","article-title":"Ultrasonography for diagnosing carpal tunnel syndrome: A meta-analysis of diagnostic test accuracy","volume":"38","author":"Tai","year":"2012","journal-title":"Ultrasound Med. Biol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"793","DOI":"10.2214\/ajr.159.4.1529845","article-title":"Carpal tunnel syndrome: Diagnosis with high-resolution sonography","volume":"159","author":"Buchberger","year":"1992","journal-title":"AJR Am. J. Roentgenol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1016\/j.cnp.2017.07.004","article-title":"Standard median nerve ultrasound in carpal tunnel syndrome: A retrospective review of 1,021 cases","volume":"2","author":"Billakota","year":"2017","journal-title":"Clin. Neurophysiol. Pract."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1041","DOI":"10.1007\/s10072-019-03756-z","article-title":"The controversy of the normal values of ultrasonography in carpal tunnel syndrome: Diagnostic accuracy of wrist-dependent CSA revisited","volume":"40","author":"Meulstee","year":"2019","journal-title":"Neurol. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"864","DOI":"10.1002\/mus.23691","article-title":"Reference values for nerve ultrasonography in the upper extremity","volume":"47","author":"Won","year":"2013","journal-title":"Muscle Nerve"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1002\/mus.23912","article-title":"Normal values of median nerve cross-sectional area obtained by ultrasound along its course in the arm with electrophysiological correlations, in 100 Asian subjects","volume":"49","author":"Bathala","year":"2014","journal-title":"Muscle Nerve"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1089","DOI":"10.1007\/s11999-010-1637-5","article-title":"The sensitivity and specificity of ultrasound for the diagnosis of carpal tunnel syndrome: A meta-analysis","volume":"469","author":"Fowler","year":"2011","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Torres-Costoso, A., Mart\u00ednez-Vizca\u00edno, V., \u00c1lvarez-Bueno, C., Ferri-Morales, A., and Cavero-Redondo, I. (2018). Accuracy of Ultrasonography for the Diagnosis of Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis. Arch. Phys. Med. Rehabil., 99.","DOI":"10.1016\/j.apmr.2017.08.489"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/j.jhsa.2018.11.010","article-title":"False-Positive Rates for Nerve Conduction Studies and Ultrasound in Patients Without Clinical Signs and Symptoms of Carpal Tunnel Syndrome","volume":"44","author":"Fowler","year":"2019","journal-title":"J. Hand Surg. Am."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"577052","DOI":"10.3389\/fneur.2020.577052","article-title":"Augmented Diagnostic Accuracy of Ultrasonography for Diagnosing Carpal Tunnel Syndrome Using an Optimised Wrist Circumference-Dependent Cross-Sectional Area Equation","volume":"11","author":"Meulstee","year":"2020","journal-title":"Front. Neurol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"625565","DOI":"10.3389\/fneur.2021.625565","article-title":"Wrist Circumference-Dependent Upper Limit of Normal for the Cross-Sectional Area Is Superior Over a Fixed Cut-Off Value in Confirming the Clinical Diagnosis of Carpal Tunnel Syndrome","volume":"12","author":"Beekman","year":"2021","journal-title":"Front. Neurol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1353","DOI":"10.1016\/j.clinph.2008.01.101","article-title":"The ultrasonographic wrist-to-forearm median nerve area ratio in carpal tunnel syndrome","volume":"119","author":"Massey","year":"2008","journal-title":"Clin. Neurophysiol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"(1993). Practice parameter for carpal tunnel syndrome (summary statement). Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology, 43, 2406\u20132409.","DOI":"10.1212\/WNL.43.11.2406"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1447","DOI":"10.2105\/AJPH.88.10.1447","article-title":"Consensus criteria for the classification of carpal tunnel syndrome in epidemiologic studies","volume":"88","author":"Rempel","year":"1998","journal-title":"Am. J. Public Health"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"American Association of Electrodiagnostic Medicine, American Academy of Neurology, and American Academy of Physical Medicine and Rehabilitation (2002). Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: Summary statement. Muscle Nerve, 25, 918\u2013922.","DOI":"10.1002\/mus.10185"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1569","DOI":"10.1016\/j.clinph.2007.03.024","article-title":"Evidence of altered motor axon properties of the ulnar nerve in carpal tunnel syndrome","volume":"118","author":"Ginanneschi","year":"2007","journal-title":"Clin. Neurophysiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1111\/j.1600-0404.1997.tb00271.x","article-title":"Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome hands","volume":"96","author":"Padua","year":"1997","journal-title":"Acta Neurol. Scand."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Falsetti, P., Conticini, E., Gaggiano, C., Baldi, C., Tarsia, M., Bardelli, M., and Frediani, B. (2022). Doppler and Spectral Ultrasound of Sacroiliac Joints in Pediatric Patients with Suspected Juvenile Spondyloarthritis. Diagnostics, 12.","DOI":"10.3390\/diagnostics12040992"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Fu, T., Cao, M., Liu, F., Zhu, J., Ye, D., Feng, X., and Bai, Y. (2015). Carpal tunnel syndrome assessment with ultrasonography: Value of inlet-to-outlet median nerve area ratio in patients versus healthy volunteers. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0116777"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"726","DOI":"10.4329\/wjr.v8.i8.726","article-title":"Peripheral nerve imaging: Not only cross-sectional area","volume":"8","author":"Tagliafico","year":"2016","journal-title":"World J. Radiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3043","DOI":"10.1002\/jum.15012","article-title":"Diagnostic Accuracy of Ultrasound Parameters in Carpal Tunnel Syndrome: Additional Criteria for Diagnosis","volume":"38","author":"Fidel","year":"2019","journal-title":"J. Ultrasound Med."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2922","DOI":"10.2106\/JBJS.H.01653","article-title":"Ultrasound assessment of the displacement and deformation of the median nerve in the human carpal tunnel with active finger motion","volume":"91","author":"Yoshii","year":"2009","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1002\/mus.26624","article-title":"Ultrasound elastography for the evaluation of peripheral nerves: A systematic review","volume":"60","author":"Wee","year":"2019","journal-title":"Muscle Nerve"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2855","DOI":"10.1016\/j.ultrasmedbio.2019.07.409","article-title":"Utility of Ultrasound Elastography in Evaluation of Carpal Tunnel Syndrome: A Systematic Review and Meta-analysis","volume":"45","author":"Lin","year":"2019","journal-title":"Ultrasound Med. Biol."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Charles, S., Oommen, K., Ong, J., and Fowler, J.R. (2021). Use of Ultrasound in Patients With Carpal Tunnel Syndrome: A Cost-Effective Solution to Reduce Delays in Surgical Care. J. Hand Surg. Am., 47.","DOI":"10.1016\/j.jhsa.2021.08.008"}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/12\/11\/2621\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:04:52Z","timestamp":1760144692000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/12\/11\/2621"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,10,28]]},"references-count":32,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2022,11]]}},"alternative-id":["diagnostics12112621"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics12112621","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,10,28]]}}}