title: Prevalence of the juxtaphrenic peak after upper lobectomy.
abstract: OBJECTIVE
  The purpose of this study was to determine the prevalence of the juxtaphrenic peak after upper lobectomy in a large number of consecutive patients.
  
  
  METHODS
  Available chest radiographs of 172 of 199 sequential patients who had undergone upper lobectomy in a university hospital were evaluated for the presence of a juxtaphrenic peak. The study included 98 cases with right upper lobectomy and 74 with left upper lobectomy. Radiographs were grouped in three postoperative periods: period I, within 7 days after lobectomy (n = 142); period II, between 8 and 30 days (n = 113); and period III, 31 days or more after lobectomy (n = 101). Four experienced radiologists in consensus determined the prevalence of the "juxtaphrenic peak sign," in relation to age, sex, side of lobectomy, positioning (erect or supine), presence of juxtadiaphragmatic abnormalities, and time interval since surgery.
  
  
  RESULTS
  The prevalence of the juxtaphrenic peak sign gradually increased from 40.6% in period I to 71.9% in period III after right upper lobectomy (p < 0.01), and from 19% to 47.7%, respectively, after left upper lobectomy (p < 0.01). Its overall prevalence was significantly higher after right upper lobectomy (58.2%) than after left upper lobectomy (40.5%) (p = 0.02), and on erect chest films (51.4%) than on supine ones (28.9%).
  
  
  CONCLUSIONS
  The prevalence of the juxtaphrenic peak sign increases gradually during the weeks following lobectomy. It is more frequent on erect films and after right upper lobectomy. The juxtaphrenic peak may serve as an additional useful radiologic sign suggesting upper lobectomy.
authors.affiliation: Department of Diagnostic Imaging, Chaim Sheba Medical Center, Sackler School of Medicine, Tel-Aviv University, Tel Hashomer, 52621 Israel.
authors.forename: E
authors.initials: E
authors.lastname: Konen
authors.forename: J
authors.initials: J
authors.lastname: Rozenman
authors.forename: D A
authors.initials: DA
authors.lastname: Simansky
authors.forename: A
authors.initials: A
authors.lastname: Yellin
authors.forename: I
authors.initials: I
authors.lastname: Greenberg
authors.forename: O
authors.initials: O
authors.lastname: Konen
authors.forename: M
authors.initials: M
authors.lastname: Hertz
authors.forename: Y
authors.initials: Y
authors.lastname: Itzchak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy / Q000009:adverse effects*; D015995:Prevalence; D001261:Pulmonary Atelectasis / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000209:etiology; D011859:Radiography