Facing the challenge of venous thromboembolism prevention in patients undergoing major abdominal surgical procedures for gastrointestinal cancer

Table 2 Imaging modalities for pulmonary embolism verification

PE	ECG	CTPA	V/Q Scan	MRA
Findings	Sinus tachycardia Non-specific ST-T disorders S1Q3T3 pattern Atrial fibrillation Right heart strain	Intraluminal filling defect of pulmonary artery after injection of contrast material	Ventilated area not perfused	Increased signal intensity of pulmonary thrombi within pulmonary artery after injection of gadolinium
Advantages	Immediate Costless	Criterion standard for diagnosis	Radiation dose lower than CTPA	High sensitivity and specificity for central, lobar, and segmental emboli
Disadvantages	Low sensitivity and specificity	Invasiveness Hypersensitivity reactions Renal toxicity	-	Inadequate for subsegmental emboli

CTPA: CT pulmonary angiography; V/Q: Ventilation/perfusion; MRA: Magnetic resonance angiography.