Arteria praebronchialis found on MDCT: potentially dangerous aberrant artery supplying the left lower lobe.
OBJECTIVE
To describe the incidence and CT features of a rare branching pattern of the pulmonary artery, the Arteria praebronchialis (AP): According to the initial description, the AP originates as the first branch of the left pulmonary artery, crosses the front of the left mainstem bronchus and then runs along the mediastinal margin as it gives off branches to one or more of the basal segments.


METHODS
Since the incidental discovery of the first patient, contrast-enhanced CT was screened by one radiologist for the presence of AP, until three more cases were identified. In those four patients, segmental and lobar branching patterns of the AP were assessed.


RESULTS
The estimated incidence of the AP was 0.03%. All four patients were men. Compared to the normal interlobar artery, the AP was smaller (n = 2), larger (n = 1), or of an equal size (n = 1). The segmental branches of the AP to the upper lobe (present in three patients) were A3 and A4 (n = 1), A3 and A5 (n = 1) and A4+5 (n = 1), respectively. Regarding the supply of the left lower lobe, AP gave off A7+8 and A9 (n = 2), A7+8 (n = 1), and A7 and A10 (n = 1), respectively. In two patients, a contralateral variant of pulmonary arterial branching was found, with (right) A7 arising as the first branch of right pulmonary artery.


CONCLUSIONS
The AP is extremely rare, but has a strong male predilection and highly diverse branching patterns in both the current study and the literature. Radiologists should familiarize themselves with the CT features of this surgically important variation, and be able to describe its lobar and segmental blood supply.
Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
Ji Hyun
JH
Hong
Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
Hyun Jung
HJ
Kim
Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea. lepolder@gmail.com.
Dae Hee
DH
Han
Department of Thoracic Surgery, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
Sook Hwan
SH
Sung
Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
Myeong Im
MI
Ahn
Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
Jung Im
JI
Jung
D000328:Adult; D000368:Aged; D003287:Contrast Media; D006801:Humans; D033162:Incidental Findings; D008168:Lung / Q000002:abnormalities / Q000098:blood supply* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement; D054079:Vascular Malformations / Q000000981:diagnostic imaging*
D003287:Contrast Media
Aberrant right A7; Anatomic variation; Arteria praebronchialis; Multi-detector computed tomography