From Juergen Hetzel and colleagues: VPCT measurements of lung lesions

http://www.ncbi.nlm.nih.gov/pubmed/21794997

Eur J Radiol. 2011 Jul 25. [Epub ahead of print]
Intraobserver and interobserver agreement of volume perfusion CT (VPCT) measurements in patients with lung lesions.
Sauter AW, Merkle A, Schulze M, Spira D, Hetzel J, Claussen CD, Horger MS.
Source
Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tuebingen, Germany.

Abstract
OBJECTIVES:
To evaluate intraobserver and interobserver agreement of manually encompassed lung lesions for perfusion measurements using volume-perfusion computed tomography (VPCT).

MATERIALS AND METHODS:
Institutional review board approval and informed consent were obtained. HIPAA guidelines were followed. A 65-s dynamic study was acquired with scan parameters 80kV, 60mAs (80mAs for patients ≥70kg), 128×0.6mm collimation. Blood flow (BF), blood volume (BV) and K(trans) parameters were determined by syngo volume perfusion CT body with 88 lesions analyzed retrospectively.

RESULTS:
Within-subject coefficients of variation for intraobserver agreement (range 6.59-12.82%) were superior to those for interobserver agreement (range 21.75-38.30%). Size-dependent analysis revealed lower agreements for lesions <4cm as compared to larger lesions. Additionally, agreements of the upper, middle and lower lung zones were different.

CONCLUSIONS:
Intraobserver agreement was substantial for VPCT lung cancer perfusion measurements encouraging the use for tumor characterization and therapy response monitoring. Interobserver agreement is limited and unexperienced readers should be trained before using this new method.