title: First-pass perfusion of non-small-cell lung cancer (NSCLC) with 64-detector-row CT: a study of technique repeatability and intra- and interobserver variability.
abstract: OBJECTIVE
  This study was done to prospectively assess the repeatability and intra- and interobserver variability of first-pass perfusion with 64-detector-row computed tomography (CT) in non-small-cell lung cancer (NSCLC) with a maximum diameter of up to 8 cm.
  
  
  METHODS
  Twelve patients with NSCLC underwent 64-detector-row first-pass CT perfusion (CTP) of the whole tumour. Two different techniques were used according to lesion size (cine mode; sequential mode). After 24 h, each study was repeated to assess repeatability. Lesion blood volume (BV), blood flow (BF), mean transit time (MTT) and peak enhancement intensity (PEI) were automatically calculated by two chest radiologists in two different reading sessions. Intra- and interobserver variability was also assessed.
  
  
  RESULTS
  The first-pass CTP technique was repeatable and precise with within-subject coefficient of variation (WCV) of 9.3, 16.4, 11.2 and 14.9 %, respectively, for BV, BF, MTT and PEI. High intra- and interobserver agreement was demonstrated for each perfusion parameter, with Cronbach's α coefficients and intraclass correlation coefficients ranging from 0.99 to 1. Precision of measurements was slightly better for intraobserver analysis with WCV ranging between 1.05 and 3.03 %.
  
  
  CONCLUSIONS
  Non-small-cell lung cancer first-pass perfusion performed with 64-detector-row CT showed good repeatability and high intra- and interobserver agreement for all perfusion parameters and may be considered a reliable and robust tool for assessing tumour vascularisation.
authors.affiliation: Department of Bioimaging and Radiological Sciences, Catholic University, "A. Gemelli" Hospital, Largo A. Gemelli 8, 00168, Rome, Italy, anna.larici@rm.unicatt.it.
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Larici
authors.forename: Lucio
authors.initials: L
authors.lastname: Calandriello
authors.forename: Michele
authors.initials: M
authors.lastname: Amato
authors.forename: Roberta
authors.initials: R
authors.lastname: Silvestri
authors.forename: Annemilia
authors.initials: A
authors.lastname: del Ciello
authors.forename: Francesco
authors.initials: F
authors.lastname: Molinari
authors.forename: Chiara
authors.initials: C
authors.lastname: de Waure
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Vita
authors.forename: Giulia
authors.initials: G
authors.lastname: Carnassale
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bonomo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*