Ga68 V/Q PET/CT for Pulmonary Embolism Diagnosis: a Diagnostic Accuracy Study vs CT Pulmonary Angiography

Gallium68 Ventilation/Perfusion PET/CT for Pulmonary Embolism Diagnosis: a Diagnostic Accuracy Study vs CT Pulmonary Angiography

This study evaluates the diagnostic accuracy (sensitivity, specificity) of V/Q PET/CT for the diagnosis of pulmonary embolism (PE), using CT pulmonary angiography as a reference standard.

V/Q PET/CT imaging is now possible by substituting 99mTc with 68Ga, a positron-emitting radionuclide, using the same carrier molecules as conventional V/Q imaging. Ventilation imaging can be performed with 68Ga-carbon nanoparticles using the same synthesis device as Technegas. Perfusion imaging can be performed with 68Ga-macroaggregated albumin (68Ga-MAA).Technical advantages of PET compared to SPECT include higher sensitivity, higher spatial and temporal resolution and superior quantitative capability. This offers the opportunity to improve the accuracy of V/Q imaging in patients with suspected PE, while decreasing the acquisition time.

The aim is to perform a formal diagnostic accuracy study of V/Q PET/CT for PE, using CTPA as a reference standard.

Patients with suspected acute PE undergo CTPA and V/Q PET/CT imaging within 24 hours.

V/Q PET/CT images are not used for patients management.

After completion of inclusion, central readings of scans will be conducted independently.

Inclusion Criteria:

• Patient with suspected first episode of acute PE,
• Age ≥ 18 years .
• Insured patient.

Exclusion Criteria:

• Patients with a clinically suspected massive PE.
• Contraindication to contrast media (including renal insufficiency with creatinine clearance < 30 ml/min).
• Inability to perform CTPA and V/Q PET/CT within 24 hours.
• History of deep vein thrombosis or PE
• Unable/unwilling to give informed consent.
• Pregnancy / breast-feeding.
• Patient under guardianship or curatorship