The Patent Ductus Arteriosus in Adults with Special Focus on Role of CT

Figure 1. Representative case of small PDA initially diagnosed on non-gated chest CT in a 36-year-old male patient. A conically shaped protrusion (arrow on A,B) of PDA arising from the descending thoracic aorta at the 12 o’clock position is noted at the level of trachea on an axial CT image. The absence of calcification argues against a calcified ligamentum arteriosum. Note that the PDA is more easily identified on coronal (arrow on C,D) and sagittal CT images (arrow on E). AA, DA, A, and PA indicate ascending aorta, descending aorta, aorta, and pulmonary artery, respectively.

Figure 2. Representative cases of PDA subtypes (arrow on types A–D). ECG-gated curved multi-planar CT image (D) shows a peculiar Y-shaped PDA that has two openings at the pulmonic end of PDA. The case may be categorized as a type D or an unclassified subtype of PDA. DA, A, and PA indicate descending aorta, aorta, and pulmonary artery, respectively.

Figure 3. Representative cases of conically shaped PDA with a valve-like structure at the pulmonic end (arrow head on A) and in its absence (arrow on B). Amplatzer occluder device (arrow on C) was successfully administered in a patient with conically shaped PDA (Same patient as B).

Figure 4. A case of PDA with Eisenmenger syndrome initially diagnosed by non-ECG gated chest CT. Moderate to large sized PDA (window shaped type B) (arrows) is noted on an axial (A), coronal (B), and sagittal (C) CT image. A and PA indicate aorta and pulmonary artery, respectively. A possible discontinuity (not atrial septal defect, but patent foramen ovale) is noted in the inter-atrial septum, but is not definite in the absence of ECG-gating (arrow on D). Note enlargement of the right atrium and ventricle due to Eisenmenger syndrome. Prior transthoracic echocardiography (obtained on seven occasions) failed to diagnosis the PDA over a period of 15 years, resulting in delay in diagnosis and obviating the opportunity for surgical correction. On echocardiography, the increased pulmonary artery pressure was falsely assumed to be due to an atrial septal defect. In fact, a large atrial septal defect is typically not an associated abnormality in patients with a large PDA because the presence of large atrial septal defect would trigger closure of the PDA. This case demonstrates the value of CT identification of PDA in some cases of a large PDA. LA, LV, RA, and RV indicate left atrium, left…

Figure 5. Septic pulmonary infarction caused by embolization of vegetation or endarteritis of a PDA in a 42-year-old female with history of glioblastoma multiforme. Small conically shaped PDA (arrow) is noted on contiguous axial CT images (A–C). Note small nodular lesion (arrowhead on C) at the pulmonic end of the PDA, suggesting a vegetation or endarteritis. This finding was confirmed by subsequent echocardiography. Septic embolus is noted in the pulmonary artery in the left lower lobe (arrow on D) on a coronal CT image at the level of descending thoracic aorta. Septic pulmonary infarction with necrosis (arrowheads on D) is also demonstrated in the left lower lobe. This patient eventually died due to septic shock. A indicates aorta.

Figure 6. Typical case of calcified ligamentum arteriosum in a 32-year-old female patient. Calcification within the ligamentum arteriosum may be confused with a small PDA if only enhanced chest CT is obtained. Note calcification (arrow on A,B) within the ligamentum arteriosum at the level of tracheal bifurcation.

Figure 7. Representative case of a ductus diverticulum in a 60-year-old male, as demonstrated on a sagittal CT image at the level of aortic arch. Although a ductus diverticulum (arrow) may simulate the CT features of conically shaped PDA at the aortic end, it lacks a connection with the left main pulmonary artery.

Figure 8. PDA diagnosed initially by ECG-gated cardiac CT, leading to closure with Amplatzer duct occluder in a 46-year-old male patient who presented with dyspnea. Conically shaped PDA without valve-like structure at the pulmonic end is noted on axial (arrow on A) and sagittal (arrow on B) CT images. Left atrial and ventricular enlargement is demonstrated on an axial CT image at the level of the left ventricle (C). PDA closure by Amplatzer duct occluder was performed in this patient due to left atrial enlargement (dyspnea). ECG-gated cardiac CT angiography provided excellent anatomic detail and planimetry without motion artifact prior to PDA closure. DA, PA, LA, and LV indicate descending thoracic aorta, pulmonary artery, left atrium, and left ventricle, respectively.