Validation of RAH VQ SPECT/CT lobar quantification program using a modified version of GE Q lung

Area of Science:

• Pulmonary Medicine
• Radiology
• Medical Imaging

Background:

• Ventilation-perfusion (VQ) SPECT/CT lobar quantification is crucial for pre-operative lung assessments.
• Bronchoscopic lung volume reduction (BLVR) for emphysema relies on accurate lobar targeting.
• RAH ventilation perfusion SPECT/CT quantification (RAHVQSQ) software has shown reproducibility but requires accuracy validation.

Purpose of the Study:

• To validate the accuracy of the in-house RAHVQSQ software.
• To compare RAHVQSQ quantitative results with a modified commercial program (GE Q lung).
• To assess the reliability of RAHVQSQ for pre-operative lung volume reduction planning.

Main Methods:

• Retrospective analysis of VQ SPECT/CT data from 19 subjects with advanced emphysema.
• Independent and blinded re-analysis using a modified GE Q lung software by two technologists.
• Statistical analysis including intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement (LoA) to determine interobserver variation.

Main Results:

• High ICC values (0.63–0.97) were observed for lobar differential ventilation, perfusion, and volume percentages.
• Mean differences in LoA were close to zero for all parameters, indicating good concordance.
• RAHVQSQ demonstrated strong agreement with the blinded GE Q lung assessment.

Conclusions:

• The RAHVQSQ software accurately estimates differential lobar ventilation, perfusion, and volume percentages.
• Close concordance with a validated commercial program supports the accuracy of RAHVQSQ.
• The validated RAHVQSQ methodology is reliable for pre-operative assessment in patients with advanced airway disease.