CTpulmonalisangiografie

CT pulmonary angiography (CTPA) is a contrast-enhanced computed tomography examination that visualizes the pulmonary arteries. It is commonly used to evaluate suspected acute pulmonary embolism and to characterize thoracic pathology that may mimic or accompany embolic disease. In some radiology literature the procedure is also referred to as CT pulmonary arteriography or CT pulmonalis.

Technique and protocol: An iodinated contrast agent is injected intravenously and images are acquired during the arterial phase, typically with thin-slice data and multiplanar reformats. Scanning is performed with the patient in inspiration and breath-hold. Modern protocols may use automated bolus tracking and advanced reconstructions to improve visualization and, in some centers, perfusion assessment with dual-energy CT.

Interpretation and findings: The primary goal is to identify intraluminal filling defects within the pulmonary arteries, ranging from central to subsegmental emboli. Radiologists also assess for secondary signs of PE and for alternative diagnoses such as pneumonia, edema, pneumothorax, or aortic pathology. The exam has high accuracy for clinically significant emboli but can be limited by motion, poor inspiration, or very small clots.

Safety and limitations: Iodinated contrast carries a risk of allergic reaction and contrast-induced nephropathy, particularly in patients with kidney impairment. Radiation exposure is a consideration, especially for pregnant patients and younger individuals. Contraindications include severe contrast allergy and certain renal conditions. When CTPA is unsuitable, V/Q scintigraphy or MR angiography may be used as alternatives.