title: Radionuclide venography and its functional analysis in superior vena cava syndrome.
abstract: In addition to imaging, radionuclide venography maybe used for the functional assessment of superior vena cava (SVC) syndrome by applying the indices of transit time (TT), time of half-peak count (TH) and peak count ratio (PC ratio).
  
  
  METHODS
  Ten healthy subjects (Group N) and 107 patients with SVC syndrome (64 symptomatic and 43 asymptomatic) were studied. Images were visually assessed for collaterals or jugular venous reflux and values of the indices were calculated.
  
  
  RESULTS
  The 107 patients were subclassified into three groups according to the images obtained. Collateral circulation was seen in 37 patients (Group C). In 20 patients, jugular venous reflux was observed (Group J). Fifty patients who showed neither collaterals nor reflux were included in Group P. In comparison to Group N [3.6 +/- 0.56 see (sem)], TT values were significantly higher (p < 0.05) for Group J (7.13 +/- 1.16 sec) and Group C (7.00 +/- 0.87 sec). Values of TH were significantly prolonged (p < 0.05) for Group J (23.6 +/- 4.8 sec) and Group C (18.8 +/- 2.2 sec) in comparison to Group N (9.2 +/- 1.5 sec). PC ratio values were higher in all patient groups in comparison to Group N (3.4 +/- 0.57).
  
  
  CONCLUSIONS
  These indices are potentially useful in the initial diagnosis and post-therapeutic evaluation of SVC syndrome. In the absence of other causes, appearance of jugular venous reflux may be considered a sign of SVC syndrome.
authors.affiliation: Department of Respiratory Medicine, Tohoku University, Sendai, Japan.
authors.forename: A M
authors.initials: AM
authors.lastname: Mahmud
authors.forename: T
authors.initials: T
authors.lastname: Isawa
authors.forename: T
authors.initials: T
authors.lastname: Teshima
authors.forename: T
authors.initials: T
authors.lastname: Hirano
authors.forename: Y
authors.initials: Y
authors.lastname: Anazawa
authors.forename: M
authors.initials: M
authors.lastname: Miki
authors.forename: T
authors.initials: T
authors.lastname: Nukiwa
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D002283:Carcinoma, Bronchogenic / Q000150:complications; D016022:Case-Control Studies; D003097:Collateral Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D007601:Jugular Veins / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000150:complications; D008297:Male; D008479:Mediastinal Neoplasms / Q000150:complications; D008875:Middle Aged; D011877:Radionuclide Imaging; D013479:Superior Vena Cava Syndrome / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D013668:Technetium Tc 99m Aggregated Albumin; D013997:Time Factors
chemical_list: D013668:Technetium Tc 99m Aggregated Albumin