A 72-year-old man with a history of recent hip fracture (immobilized for 2 weeks) presents with sudden-onset dyspnea, tachycardia (HR 118 bpm), and hypoxemia (SpO₂ 88% on room air). CTPA is performed and shows a large filling defect in the right main pulmonary artery extending into the right lower lobe segmental arteries. The right ventricle appears dilated. Which of the following CT findings would best indicate hemodynamic compromise and guide the decision for thrombolysis?