title: Imaging lung function in mice using SPECT/CT and per-voxel analysis.
abstract: Chronic lung disease is a major worldwide health concern but better tools are required to understand the underlying pathologies. Ventilation/perfusion (V/Q) single photon emission computed tomography (SPECT) with per-voxel analysis allows for non-invasive measurement of regional lung function. A clinically adapted V/Q methodology was used in healthy mice to investigate V/Q relationships. Twelve week-old mice were imaged to describe normal lung function while 36 week-old mice were imaged to determine how age affects V/Q. Mice were ventilated with Technegas™ and injected with (99m)Tc-macroaggregated albumin to trace ventilation and perfusion, respectively. For both processes, SPECT and CT images were acquired, co-registered, and quantitatively analyzed. On a per-voxel basis, ventilation and perfusion were moderately correlated (R = 0.58±0.03) in 12 week old animals and a mean log(V/Q) ratio of -0.07±0.01 and standard deviation of 0.36±0.02 were found, defining the extent of V/Q matching. In contrast, 36 week old animals had significantly increased levels of V/Q mismatching throughout the periphery of the lung. Measures of V/Q were consistent across healthy animals and differences were observed with age demonstrating the capability of this technique in quantifying lung function. Per-voxel analysis and the ability to non-invasively assess lung function will aid in the investigation of chronic lung disease models and drug efficacy studies.
authors.affiliation: Department of Medicine, Division of Respirology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Brian N
authors.initials: BN
authors.lastname: Jobse
authors.forename: Rod G
authors.initials: RG
authors.lastname: Rhem
authors.forename: Cory A J R
authors.initials: CA
authors.lastname: McCurry
authors.forename: Iris Q
authors.initials: IQ
authors.lastname: Wang
authors.forename: N Renée
authors.initials: NR
authors.lastname: Labiris
mesh_terms: D000818:Animals; D002908:Chronic Disease; D005260:Female; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D064847:Multimodal Imaging / Q000295:instrumentation / Q000379:methods*; D049268:Positron-Emission Tomography; D012123:Pulmonary Ventilation; D014057:Tomography, X-Ray Computed