{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T21:13:04Z","timestamp":1773263584265,"version":"3.50.1"},"reference-count":29,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2013,7,8]],"date-time":"2013-07-08T00:00:00Z","timestamp":1373241600000},"content-version":"vor","delay-in-days":7,"URL":"http:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Applied Clin Med Phys"],"published-print":{"date-parts":[[2013,7]]},"abstract":"The purpose of this study was to identify the normal variance of emphysema index (EI) measured in examinations acquired with 64 multidetector\u2010row computed tomography (64\u2010MDCT). A longitudinal, noninterventional study was performed retrieving all patients in our institution who are currently registered in our lung nodule protocol. All patients with clinical, functional, or significant radiological changes were excluded. We assumed that EI should remain unchanged within a short period of time. We reviewed 475 MDCTs in order to select 50 clinically stable patients who had two sequential chest MDCTs performed within a time interval of less than three months, and who presented at least one lung free of abnormalities but emphysema. CT densitovolumetry was used to calculate EI with thresholds set at Hounsfield units (HUs) (EI\u2010950) and HUs (EI\u2010970); on both studies from each patient. We observed the variation of total lung volume (TLV), mean lung density (MDL), and EI for measurements at the baseline and at follow\u2010up scans. Differences observed between baseline and follow\u2010up measurements were: ; ; ; ; ; and ; . The correlations obtained were the following: , , . Accepting that emphysema would remain unchanged within three months on stable patients, differences of less than 0.89% for EI\u2010950 and of less than 0.23% for EI\u2010970 are within the variance of the method.<\/jats:p>PACS number: 87.50.ct<\/jats:p>","DOI":"10.1120\/jacmp.v14i4.4215","type":"journal-article","created":{"date-parts":[[2017,2,27]],"date-time":"2017-02-27T23:08:54Z","timestamp":1488236934000},"page":"254-262","source":"Crossref","is-referenced-by-count":4,"title":["Normal variance in emphysema index measurements in 64 multidetector\u2010row computed tomography"],"prefix":"10.1002","volume":"14","author":[{"given":"Bruno","family":"Hochhegger","sequence":"first","affiliation":[{"name":"Radiology Division Federal University of Rio de Janeiro Rio de Janeiro Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Klaus L.","family":"Irion","sequence":"additional","affiliation":[{"name":"Radiology Division The Royal Liverpool and Broadgreen University Hospitals Liverpool United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giordano R.T.","family":"Alves","sequence":"additional","affiliation":[{"name":"Radiology Division University Hospital of Santa Maria Santa Maria Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"suffix":"Jr.","given":"Arthur S.","family":"Souza","sequence":"additional","affiliation":[{"name":"Radiology Division University of S\u00e3o Jos\u00e9 do Rio Preto S\u00e3o Jos\u00e9 do Rio Preto Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John","family":"Holemans","sequence":"additional","affiliation":[{"name":"Radiology Division The Royal Liverpool and Broadgreen University Hospitals Liverpool United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dhivya","family":"Murthy","sequence":"additional","affiliation":[{"name":"Radiology Division The Royal Liverpool and Broadgreen University Hospitals Liverpool United Kingdom"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Edson","family":"Marchiori","sequence":"additional","affiliation":[{"name":"Radiology Division Federal University of Rio de Janeiro Rio de Janeiro Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2013,7,8]]},"reference":[{"issue":"1","key":"e_1_2_6_2_1","first-page":"182","article-title":"The definition of emphysema. 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