Abstract
Abstract
Purpose
Kerley A-lines are generally apparent in patients with pulmonary edema or lymphangitic carcinomatosis. There are two main thoughts regarding the etiology of Kerley A-lines, but no general agreement. Specifically, the lines are caused by thickened interlobular septa or dilated anastomotic lymphatics. Our purpose was to determine the anatomic structure represented as Kerley A-lines using 3D-CT lung segmentation analysis.
Materials and methods
We reviewed 139 charts of patients with lymphangitic carcinomatosis of the lung who had CT and X-ray exams with a maximum interval of 7 days. The presence of Kerley A-lines on X-ray was assessed by a radiologist. The A-lines on X-ray were defined as follows: dense; fine (< 1 mm thick); ≥ 2 cm in length, radiating from the hilum; no bifurcation; and not adjacent to the pleura. For cases with Kerley A-lines on X-ray, three radiologists agreed that the lines on CT corresponded with Kerley A-lines. The incidence of A-lines and the characteristics of the lines were investigated. The septal lines between lung segments were identified using a 3D-CT lung segmentation analysis workstation. The percentage of agreement between the A-lines on CT and lung segmental lines was assessed.
Results
On chest X-ray, 37 Kerley A-lines (right, 16; left, 21) were identified in the 22 cases (16%). Of these, 4 lungs with 12 lines were excluded from analysis due to technical reasons. Nineteen of the 25 lines (76%) corresponded to the septal lines on CT. Of these, 11 lines matched with automatically segmented lines (intersegmental septa, 4; intersubsegmental septa, 7) by the workstation. Two lines (8%) represented fissures. Four lines corresponded to the bronchial wall/artery (3 lines, 12%) or vein (1 line, 4%).
Conclusion
Kerley A-lines primarily represented thickened and continued interlobular septal lines that corresponded to the septa between lung segments and subsegments.
Publisher
Springer Science and Business Media LLC
Subject
Radiology, Nuclear Medicine and imaging
Reference13 articles.
1. Kerley PJ. Occupational disease of the lungs. In: Shanks C, Kerley P, editors. A text-book of X-ray diagnosis, vol. 2. 2nd ed. London: H. K. Lewis; 1951. p. 404.
2. Kerley PJ. The pulmonary circulation. In: Shanks C, Kerley P, editors. A text-book of X-ray diagnosis, vol. 2. 4th ed. London: H. K. Lewis; 1972. p. 40–7.
3. Felson B. The hila and pulmonary vessels. In: Chest roentgenology. Tronto: Atbs Publisher; 1973. p. 241–50.
4. Heitzman ER, Ziter FM, Markarian B, McClennan BL, Sherry HT. Kerley’s interlobular septal lines: roentgen pathologic correlation. Am J Roentgenol Radium Ther Nucl Med. 1967. https://doi.org/10.2214/ajr.100.3.578.
5. Grainger RG. Interstitial pulmonary oedema and its radiological diagnosis: a sign of pulmonary venous and capillary hypertension. Br J Radiol. 1958. https://doi.org/10.1259/0007-1285-31-364-201.