Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Anomalous systemic arterial supply to the normal lung
- Radiologic Findings
- Chest simple radiographs show ill-defined retrocardiac opacity corresponding to the anomalous artery.
Contrast enhanced axial chest CT scan shows arterial supply from thoracic aorta and enlarged draining right pulmonary vein in basal segment of LLL and mild interlobular and intralobular septal thickening in LLL with GGO, suggesting an area of relative hypervascularity and/or intra-alveolar hemorrhage.
- Brief Review
- Systemic arterialization of the lung without pulmonary sequestration is the rarest form of anomalous systemic arterial supply to the lung. This condition is characterized by an aberrant arterial branch arising from the aorta which supplies an area of lung parenchyma with normal bronchopulmonary anatomy.
The basal segments of left lower lobe are the most commonly affected site, although rarely other sites can be affected. The systemic artery most commonly arises from the thoracic aorta, but can arise from abdominal aorta or celiac axis and even more rarely from left subclavian and internal mammary artery.
Most patients are asymptomatic. The most common symptom is hemoptysis. Other manifestations include exertional dyspnea, murmur.
A retrocardiac tubular structure or a focal area of consolidation may be evident on chest X-Ray. Computed tomography may reveal a focal area of ground glass density, indicating an area of relative hypervascularity and/or intra-alveolar hemorrhage. CT can also demonstrate an aberrant systemic arterial supply to part of the lung. Thoracic CT is the most useful test in the evaluation of patients with suspected abnormal systemic arterial supply to the lung, as it demonstrates both the bronchial and vascular anatomy of the lung. CT angiography can clearly depict the origin of the aberrant systemic artery. MRI has also been reported to be useful in identifying an anomalous vessel originating from the aorta.
The radiological differential diagnoses include true sequestration and, less likely, hypogenetic lung syndrome. On plain radiograph, intralobar sequestration usually manifests as an intrapulmonary lesion in the left lower lobe. Extralobar sequestration commonly appears as a single, well-defined homogenous opacity located in the pleural space between the left lower lobe and the diaphragm. Evidence of a homogenous or heterogeneous lung mass supplied by a systemic arterial branch on CT should raise suspicion of lung sequestration. MRI can be useful to differentiate the cystic, solid, hemorrhagic and mucous components of the lung mass, as well as providing details of the venous drainage and the abnormal systemic artery. On the other hand, hypogenetic lung syndrome is associated with volume loss of the right lung, which is usually evident on chest X-Ray. CT angiography and MRI reveal the typical vascular abnormalities of this rare condition.
Treatment options include surgery (lobectomy and segmentectomy), when aberrant systemic artery is the only supply, and occlusion of the aberrant vessel by surgical ligation or endovascular treatment.
- References
- 1. Kyung-Hyun Do, Jin Mo Goo, Jung-Gi Im, Kyoung Won Kim, Jin Wook Chung, Jae Hyung Park. “Systemic Arteri al Supply to the Lungs in Adults: Spiral CT Findings” Radiographics 2001
2. Marcela Mautone, Parm Naidoo. “A case of systemic arterial supply to the right lower lobe of the lung: imaging findings and review of the literature” J Radiol Case Rep. 2014 Mar; 8(3): 9–15.
3. Ashu Seith Bhalla, Pankaj Gupta, Amar Mukund, Arvind Kumar, and Mudit Gupta. “Anomalous Systemic Artery to a Normal Lung: A Rare Cause of Hemoptysis in Adults” Oman Med J. 2012 Jul; 27(4): 319–322.
4. Bo Ra Kim, MD, Jeong-Hyun Jo, MD, Byeong-Ho Park, MD. Transarterial Embolization Treatment for Aberrant Systemic Arterial Supply to the Normal Lung: A Case Report and Literature Review. J Korean Soc Radiol 2017;76(6):395-402.
- Please refer to
- Case 824
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- Keywords
- Vascular, congenital,