Lung function quantification with numerical ventilation/perfusion ratio

Nuklearmedizin - NuclearMedicine, vol. 62, pp. 134

Abstract

Ziel/Aim In normal lung tissue, ventilation and perfusion should be in the same ratio. In lung diseases, the ventilation/perfusion ratio (VQR) can be different from 1, which is represented in the VQR diagram by a change in the slope of the regression line. The aim of this study is to use 3D lung quantification software to show this VQR ratio for normal lung tissue compared to the entire study population. Methodik/Methods A group of n=100 patients were examined with ventilation/perfusion single photon emission tomography (V/Q-SPECT/CT on a SPECT/CT Optima NM/CT 640 (GE Healthcare). 3D lung quantification was performed using Q.Lung: Xeleris 4.0 software, GE Healthcare, Haifa, Israel. The numerical ventilation/perfusion ratio was determined for each lung lobe. A normalisation algorithm implemented in QLUNG takes into account the different activity ratios of ventilation and perfusion in the quantification. After evaluation of the SPECT/CT images by a consensus of physicians, patients with normal lung structure were identified. The slopes of the regression lines for patients with normal lung structure and abnormal lung structure were compared to the entire study population. Ergebnisse/Results A group of n=15 patients with normal lung structure were identified. For all five lung lobes (right upper lobe, right middle lobe, right lower lobe, left upper lobe, left lower lobe), the measure of the slope of the VQR quotient for patients with normal lung structure was: m=0.94+/-0.04, for patients with abnormal lung structure m=0.81+/-0.03 and for the whole study population: m=0.82+/-0.03. This inter-group difference is approximately 15%. Schlussfolgerungen/Conclusions From the analysis of the slope values, conclusions can be derived about the health status of the study population. A slope of about 0.81 suggests a proportion of patients with abnormal lung structure. A quotient of 0.94 mainly represents patients with normal lung structure. Publication History Article published online: 30 March 2023 © 2023. Thieme. All rights reserved. Georg Thieme Verlag Rüdigerstraße 14, 70469 Stuttgart, Germany

Authors 4

1. Julia Katharina Vogt

   University Medical Center Hamburg-Eppendorf

   Affiliation as printed

   Universitätsklinikum Hamburg-Eppendorf, GB Sicherheit & Compliance, Hamburg

2. Wolfgang Kurt Vogt

   Hochschule Düsseldorf University of Applied Sciences

   Affiliation as printed

   Hochschule Düsseldorf, Fachbereich Elektro- & Informationstechnik, Düsseldorf

3. Alexander Heinzel

   University Hospital in Halle

   Affiliation as printed

   Universitätsklinikum Halle (Saale), Nuklearmedizin, Halle (Saale)

4. Felix Manuel Mottaghy Aachen Klinik für Nuklearmedizin

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Universitätsklinikum RWTH Aachen, Klinik für Nuklearmedizin, Aachen