E4725. CT Lung Fused With Quantitative Lung Perfusion in Pre-Endobronchial Valve Replacement Surgery
  1. Johnny Yang; University of Mississippi Medical Center
  2. Logan Ryals; University of Mississippi Medical Center
  3. Jeffrey Roux; University of Mississippi Medical Center
  4. Gregory Vance; University of Mississippi Medical Center
  5. John Salvemini; University of Mississippi Medical Center
  6. Bradley Hathaway; University of Mississippi Medical Center
  7. Vani Vijayakumar; University of Mississippi Medical Center
Significant morbidity, mortality, and healthcare costs are associated with persistent air leaks (PAL). Endobronchial valve replacement (EBVR) serves as a relatively noninvasive procedure for managing PAL, spontaneous pneumothorax, emphysema, and hyperinflation. Towards the goals of improving outcomes and reducing risk and complications, EBVR patient selection requires multidisciplinary considerations. Several factors are considered in presurgical EBVR evaluation: selection of an appropriate target lobe and perfusion scintigraphy findings, such as hyperinflation associated with severe emphysema in regions of lung with little or no collateral ventilation, high ipsilateral nontarget lobe perfusion, and high heterogeneity index. When compared to perfusion lung scan, gold-standard quantitative CT (qCT) has been employed to model perfusion with higher anatomical detail. However, qCT is unable to identify target lobes in homogeneous diseases, whereas scintigraphy is better suited for this application.

Educational Goals / Teaching Points
Discuss refractory COPD and differentiating COPD phenotype employing CT. Review the causes of persistent air leak, etiologies, and traditional management approaches. Compare perfusion lung scintigraphy, qCT, and VQDI for perfusion modeling and prognostication. Elucidate the multidisciplinary approach for patient selection of EBVR.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
In combination with CT, ventilation-perfusion SPECT can characterize homogenous diseases like scintigraphy and simultaneously generate ventilation-perfusion differential index (VQDI), which quantitatively agrees with qCT for evaluating perfusion. VQDI report statistically significant changes in mean difference for FEV1, target lobe volume reduction, residual volume, and St. George’s Respiratory Questionnaire score.

Fused with CT chest changes, quantitative lung perfusion scan can serve as a prognostic tool for EBVR and further aid in preoperative patient selection. For homogenous emphysema without distinct lobar targets, VQ SPECT/CT serves a valuable similar role.