PT  - JOURNAL ARTICLE
AU  - Tokihiro Yamamoto
AU  - Sven Kabus
AU  - Jens von Berg
AU  - Cristian Lorenz
AU  - Michael Goris
AU  - Billy Loo
AU  - Paul Keall
TI  - Comparison of four-dimensional (4D) CT ventilation imaging with SPECT V/Q scans
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - 1438
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/1438.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/1438.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - Background: A novel ventilation imaging method based on 4D-CT has advantages over existing methods. However, little validation has been performed.Purpose: To compare 4D-CT ventilation imaging (VCT) with SPECT ventilation (VSPECT) and perfusion (QSPECT) scans.Methods: VCT, VSPECT and QSPECT were acquired for 3 patients. VCT was compared with VSPECT and QSPECT. The spatial overlap of defects was assessed using the dice coefficient (DC). The defects were determined by (1) thresholding the SPECT images with 20%, 30% or 40% of the maximum value in the lung and (2) segmenting the same volume with lower values in VCT.Results: VCT was of higher resolution than SPECT. Figure shows example images. Visually, regions of both agreement and disagreement were identified.Table shows DCs (mean±SD) between the VCT and VSPECT or QSPECT defects. VSPECT suffered from central airway depositions of aerosols, which drove extremely high correlations. There were moderate correlations with QSPECT in all patients. Lower thresholds yielded consistently lower DCs due to differences in low-value regions.View this table:Conclusions: The 4D-CT ventilation moderately correlated with the SPECT V/Q. Ongoing studies focus on investigating more patients and spatial characteristics of the differences.