{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T15:46:54Z","timestamp":1775058414324,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,7,9]],"date-time":"2025-07-09T00:00:00Z","timestamp":1752019200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Canon Medical"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Imaging"],"abstract":"<jats:p>Ultrasound attenuation imaging (ATI) is a non-invasive method for quantifying hepatic steatosis, offering advantages over the hepatorenal index (HRI). However, its reliability can be influenced by factors such as measurement depth, ROI size, and subcutaneous fat. This paper examines the impact of these confounders on ATI measurements and discusses diagnostic considerations. In this study, 33 healthy adults underwent liver ultrasound with ATI and HRI protocols. ATI measurements were taken at depths of 2\u20135 cm below the liver capsule using small and large ROIs. Two operators performed the measurements, and inter-operator variability was assessed. Subcutaneous fat thickness was measured to evaluate its influence on attenuation values. The ATI measurements showed a consistent decrease in attenuation coefficient values with increasing depth, approximately 0.05 dB\/cm\/MHz. Larger ROI sizes increased measurement variability due to greater anatomical heterogeneity. HRI values correlated weakly with ATI and were influenced by operator technique and subcutaneous fat, the latter accounting for roughly 2.5% of variability. ATI provides a quantitative assessment of hepatic steatosis compared to HRI, although its accuracy can vary depending on the depth and ROI selection. Standardised imaging protocols and AI tools may improve reproducibility and clinical utility, supporting advancements in ultrasound-based liver diagnostics for better patient care.<\/jats:p>","DOI":"10.3390\/jimaging11070229","type":"journal-article","created":{"date-parts":[[2025,7,10]],"date-time":"2025-07-10T09:38:27Z","timestamp":1752140307000},"page":"229","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Depth-Dependent Variability in Ultrasound Attenuation Imaging for Hepatic Steatosis: A Pilot Study of ATI and HRI in Healthy Volunteers"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5988-9911","authenticated-orcid":false,"given":"Alexander","family":"Martin","sequence":"first","affiliation":[{"name":"Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, 8091 Zurich, Switzerland"}]},{"given":"Oliver","family":"Hurni","sequence":"additional","affiliation":[{"name":"Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, 8091 Zurich, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7288-877X","authenticated-orcid":false,"given":"Catherine","family":"Paverd","sequence":"additional","affiliation":[{"name":"Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, 8091 Zurich, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-6317-9087","authenticated-orcid":false,"given":"Olivia","family":"H\u00e4nni","sequence":"additional","affiliation":[{"name":"Institute of Anesthesiology and Perioperative Medicine, University Hospital Zurich, 8091 Zurich, Switzerland"}]},{"given":"Lisa","family":"Ruby","sequence":"additional","affiliation":[{"name":"Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, 8091 Zurich, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3295-6619","authenticated-orcid":false,"given":"Thomas","family":"Frauenfelder","sequence":"additional","affiliation":[{"name":"Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, 8091 Zurich, Switzerland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6317-4815","authenticated-orcid":false,"given":"Florian A.","family":"Huber","sequence":"additional","affiliation":[{"name":"Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, 8091 Zurich, Switzerland"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1038\/s41572-025-00599-1","article-title":"Metabolic dysfunction-associated steatotic liver disease in adults","volume":"11","author":"Huang","year":"2025","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1335","DOI":"10.1097\/HEP.0000000000000004","article-title":"The global epidemiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH): A systematic review","volume":"77","author":"Younossi","year":"2023","journal-title":"Hepatology"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Ho, G.J.K., Tan, F.X.N., Sasikumar, N.A., Tham, E.K.J., Ko, D., Kim, D.H., Yeo, Y.H., Srivastava, S., Thongngarm, T., and Wong, V.W.S. (Clin. Gastroenterol. Hepatol., 2025). High Global Prevalence of Steatotic Liver Disease and Associated Subtypes: A Meta-analysis, Clin. Gastroenterol. Hepatol., in press.","DOI":"10.1016\/j.cgh.2025.02.006"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1016\/j.tem.2024.02.007","article-title":"Current status and future trends of the global burden of MASLD","volume":"35","author":"Miao","year":"2024","journal-title":"Trends Endocrinol. Metab."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2296","DOI":"10.1016\/j.cgh.2021.11.004","article-title":"Clinical and Patient-Reported Outcomes From Patients with Nonalcoholic Fatty Liver Disease Across the World: Data From the Global Non-Alcoholic Steatohepatitis (NASH)\/Non-Alcoholic Fatty Liver Disease (NAFLD) Registry","volume":"20","author":"Younossi","year":"2022","journal-title":"Clin. Gastroenterol. Hepatol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1002\/hep.22742","article-title":"Liver biopsy","volume":"49","author":"Rockey","year":"2009","journal-title":"Hepatology"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Wibulpolprasert, P., Subpinyo, B., Chirnaksorn, S., Chattranukulchai Shantavasinkul, P., Putadechakum, S., Phongkitkarun, S., Sritara, C., Angkathunyakul, N., and Sumritpradit, P. (2024). Correlation between magnetic resonance imaging proton density fat fraction (MRI-PDFF) and liver biopsy to assess hepatic steatosis in obesity. Sci. Rep., 14.","DOI":"10.1038\/s41598-024-57324-3"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"763","DOI":"10.1002\/hep.29797","article-title":"Non-invasive, quantitative assessment of liver fat by MRI-PDFF as an endpoint in NASH trials","volume":"68","author":"Caussy","year":"2018","journal-title":"Hepatology"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1097\/RUQ.0000000000000605","article-title":"Liver Ultrasound Attenuation: An Ultrasound Attenuation Index for Liver Steatosis Assessment","volume":"38","author":"Gatos","year":"2022","journal-title":"Ultrasound Q."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1002\/jgh3.12615","article-title":"The ultrasound-guided attenuation parameter is useful in quantification of hepatic steatosis in non-alcoholic fatty liver disease","volume":"5","author":"Ogino","year":"2021","journal-title":"JGH Open"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1800409","DOI":"10.1109\/JTEHM.2020.3001488","article-title":"Ultrasound-Based Attenuation Imaging for the Non-Invasive Quantification of Liver Fat\u2014A Pilot Study on Feasibility and Inter-Observer Variability","volume":"8","author":"Jesper","year":"2020","journal-title":"IEEE J. Transl. Eng. Health Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2293","DOI":"10.1007\/s00330-019-06480-6","article-title":"Quantification of hepatic steatosis with ultrasound: Promising role of attenuation imaging coefficient in a biopsy-proven cohort","volume":"30","author":"Ronot","year":"2020","journal-title":"Eur. Radiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"997","DOI":"10.2214\/AJR.11.6677","article-title":"Hepatorenal index as an accurate, simple, and effective tool in screening for steatosis","volume":"199","author":"Marshall","year":"2012","journal-title":"Am. J. Roentgenol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Stahlschmidt, F.L., Tafarel, J.R., Menini-Stahlschmidt, C.M., and Baena, C.P. (2021). Hepatorenal index for grading liver steatosis with concomitant fibrosis. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0246837"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6053","DOI":"10.3748\/wjg.v25.i40.6053","article-title":"Ultrasound-based techniques for the diagnosis of liver steatosis","volume":"25","author":"Ferraioli","year":"2019","journal-title":"World J. Gastroenterol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2247","DOI":"10.1002\/jum.16242","article-title":"Liver Fat Quantification With Ultrasound: Depth Dependence of Attenuation Coefficient","volume":"42","author":"Ferraioli","year":"2023","journal-title":"J. Ultrasound Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1325","DOI":"10.1002\/jum.15512","article-title":"Performance of the Attenuation Imaging Technology in the Detection of Liver Steatosis","volume":"40","author":"Ferraioli","year":"2021","journal-title":"J. Ultrasound Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"81","DOI":"10.14309\/ctg.0000000000000081","article-title":"Detection of Liver Steatosis with a Novel Ultrasound-Based Technique: A Pilot Study Using MRI-Derived Proton Density Fat Fraction as the Gold Standard","volume":"10","author":"Ferraioli","year":"2019","journal-title":"Clin. Transl. Gastroenterol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/0301-5629(75)90038-1","article-title":"Ultrasonic attenuation in human tissue","volume":"2","author":"Chivers","year":"1975","journal-title":"Ultrasound Med. Biol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2113","DOI":"10.1121\/1.4962983","article-title":"Acoustic attenuation imaging of tissue bulk properties with a priori information","volume":"140","author":"Hooi","year":"2016","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/0301-5629(77)90064-3","article-title":"Computerized time-of-flight ultrasonic tomography for breast examination","volume":"3","author":"Glover","year":"1977","journal-title":"Ultrasound Med. Biol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2070","DOI":"10.1007\/s00330-021-08269-y","article-title":"Diagnostic performance of ultrasound attenuation imaging for assessing low-grade hepatic steatosis","volume":"32","author":"Jang","year":"2022","journal-title":"Eur. Radiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"S155","DOI":"10.1016\/j.acra.2023.05.033","article-title":"Quantitative Diagnosis of Nonalcoholic Fatty Liver Disease with Ultrasound Attenuation Imaging in a Biopsy-Proven Cohort","volume":"30","author":"Huang","year":"2023","journal-title":"Acad. Radiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1007\/s10396-021-01123-0","article-title":"Diagnostic accuracy of ultrasound-guided attenuation parameter as a noninvasive test for steatosis in non-alcoholic fatty liver disease","volume":"48","author":"Kuroda","year":"2021","journal-title":"J. Med. Ultrason."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1002\/ajum.12381","article-title":"Hepatic steatosis: Qualitative and quantitative sonographic assessment in comparison to histology","volume":"27","author":"Tan","year":"2024","journal-title":"Australas. J. Ultrasound Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1111\/1754-9485.13412","article-title":"Hepatic steatosis: Ultrasound assessment using attenuation imaging (ATI) with liver biopsy correlation","volume":"67","author":"Welman","year":"2023","journal-title":"J. Med. Imaging Radiat. Oncol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1088","DOI":"10.1016\/j.ultrasmedbio.2024.03.014","article-title":"WFUMB Guidelines\/Guidance on Liver Multiparametric Ultrasound. Part 2: Guidance on Liver Fat Quantification","volume":"50","author":"Ferraioli","year":"2024","journal-title":"Ultrasound Med. Biol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1007\/s10396-021-01124-z","article-title":"The most appropriate region-of-interest position for attenuation coefficient measurement in the evaluation of liver steatosis","volume":"48","author":"Sugimoto","year":"2021","journal-title":"J. Med. Ultrason."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2461","DOI":"10.1016\/j.ultrasmedbio.2018.07.019","article-title":"Quantitative Hepatic Fat Quantification in Non-alcoholic Fatty Liver Disease Using Ultrasound-Based Techniques: A Review of Literature and Their Diagnostic Performance","volume":"44","author":"Ozturk","year":"2018","journal-title":"Ultrasound Med. Biol."},{"key":"ref_30","first-page":"40","article-title":"Artificial intelligence in diagnostic ultrasonography","volume":"29","author":"Dicle","year":"2023","journal-title":"Diagn. Interv. Radiol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"885","DOI":"10.1002\/hed.25415","article-title":"Deep convolutional neural network for the diagnosis of thyroid nodules on ultrasound","volume":"41","author":"Ko","year":"2019","journal-title":"Head. Neck."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/S1470-2045(18)30762-9","article-title":"Diagnosis of thyroid cancer using deep convolutional neural networks: A multicohort study","volume":"20","author":"Li","year":"2019","journal-title":"Lancet Oncol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"466","DOI":"10.1007\/s11604-019-00831-5","article-title":"Using deep learning to distinguish between benign and malignant breast masses on ultrasound","volume":"37","author":"Fujioka","year":"2019","journal-title":"Jpn. J. Radiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1016\/j.diii.2019.02.009","article-title":"Diagnosis of focal liver lesions from ultrasound using deep learning","volume":"100","author":"Schmauch","year":"2019","journal-title":"Diagn. Interv. Imaging"}],"container-title":["Journal of Imaging"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2313-433X\/11\/7\/229\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:07:03Z","timestamp":1760033223000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2313-433X\/11\/7\/229"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,9]]},"references-count":34,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["jimaging11070229"],"URL":"https:\/\/doi.org\/10.3390\/jimaging11070229","relation":{},"ISSN":["2313-433X"],"issn-type":[{"value":"2313-433X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,9]]}}}