Dilated left or right descending pulmonary artery associated with pulmonary infarction and pulmonary hypertension following pulmonary embolism
1962 – Extensive review of 1,085 consecutive chest X-rays to determine the average diameter of the left and right descending pulmonary artery on a PA chest XR. Determined the upper limit of normal for right descending as 16mm in males; 15mm in females and for the left descending <17mm as normal. Measurements made at the widest point of the artery usually at the level of the 8/9 rib.
1965 – Published findings of 23 consecutive patients with pulmonary infarcts diagnosed at the Man Memorial Hospital between 1959 and 1962. Dilatation of a descending pulmonary artery occurred in all of 23 consecutive instances of pulmonary infarction. Dilation ranged from 17-22mm on the right (19 cases) and 17-26mm on the left (4 cases)
Example: Case 1/23
29 year old female post D&C for incomplete miscarriage
- a) Preoperative CXR. Right descending pulmonary artery 12 mm.
- b) Pulmonary infarction. Homogeneous density in right lower lobe. Dilated right descending pulmonary artery measuring 17 mm suggesting acute pulmonary hypertension
- c) Five days later. Right pleural effusion and persistent densities in the right lower lobe. Right descending pulmonary artery 17 mm
- d) Two months later. Decreased right pleural fluid and resolving pulmonary infarcts with linear scars. Right descending pulmonary artery again 12 mm.
- Nils Westermark (1892 – 1980) [Westermark sign 1938]
- Aubrey Otis Hampton (1900 – 1955) [Hampton hump 1940]
- Felix George Fleischner (1893 – 1969) [Fleischner sign 1959]
- C. H. Joseph Chang (1929 – 2017) [Chang sign 1965]
- Antonio Palla (1950 – ) [Palla sign 1983]
- Chang’s sign
- Palla sign
- Chang CH. The normal roentgenographic measurement of the right descending pulmonary artery in 1,085 cases. Am J Roentgenol Radium Ther Nucl Med. 1962 May;87:929-35. [PMID 13878070]
- Chang CH, Davis WC. A Roentgen sign of Pulmonary Infarction. Clin Radiol. 1965 Apr;16:141-7. [PMID 14272525]
- Palla A, Donnamaria V, Petruzzelli S, Rossi G, Riccetti G, Giuntini C. Enlargement of the right descending pulmonary artery in pulmonary embolism. AJR Am J Roentgenol. 1983 Sep;141(3):513-7. [PMID 6603760] [Palla sign]