ABSTRACT ID : IRIA

 30 yr old female came with c/o chest pain, shortness of breath, recurrent respiratory tract infections, anasarca,

CXR: Small right hemithorax with hyperlucency noted, Displacement of the mediastinum, to right side Absent hilar shadow and paucity of vascular markings on right lung field, Prominence of left hilum with pulmonary plethora Cystic lucencies noted in b/l lower zone hyperinflation of the left lung.

Right lung shows volume loss with mediastinal shift to right side Cystic bronchiectatic changes noted on right side

Enlarged main pulmonarey artery (3.8cm) and left pulmonary artery(2.4cm), Absent right pulmonary artery Decreased pulmonary vasculature noted on right side Pulmonary plethora on the left side.

Prominence of the left pulmonary artery branches The right pleural surface appears beaded because of the presence of prominent intercostal arteries serving as collateral vessels.

Reconstructed,VR images Patent ductus arteriosus Prominent main pulmonary artery,Left pulmonary artery

UNILATERAL ABSENCE OF PULMONARY ARTERY (Right pulmonary artery agenesis) Associated with Pulmonary hypertension Patent ductus arteriosus

 UAPA is estimated to be around 1 in 200,000 individuals  The main embryologic defect is an involution of the proximal sixth aortic arch of the affected side, leading to an absence of the proximal pulmonary artery.  Intrapulmonary vessels and distal portion of the affected pulmonary artery trunk can develop normally, and blood supply is achieved by systemic collaterals from bronchial, major aortopulmonary collaterals and other systemic arteries  UAPA is twice as common on the right side Symptoms-  Due to large systemic - pulmonary collaterals from bronchial,intercostal,internalmammary arteries.  Hemoptysis – 10% due to rupture of these hypertrophied collaterals.  Recurrent chest infections  Pulmonary hypertension - >40yrs.

Left-sided agenesis seems to be more frequently associated with cardiac abnormalities such as tetralogy of Fallot, septal defects, patent ductus arteriosus, coarctation of the aorta and transposition of great vessels and therefore early diagnosis and surgical repair are required during the first year of life. Patients with isolated right UAPA survive into adulthood with minimal symptoms, making the diagnosis of such cases more difficult.

The radiologic features Small hemithorax, Ipsilateral displacement of the mediastinum, Absence of the corresponding pulmonary artery, Reticular densities along the pleura and within the lung, - due to systemic collateral circulation. Ipsilateral hemidiaphragm elevation with volume loss of the affected lung, Absent hilar shadow, hyperinflation of the contralateral lung.

 Patient positioning Rotation Scoliosis  Chest wall defect Mastectomy Poland syndrome (absent pectoralis muscle)  Pneumothorax  C/L Pleural effusion  Airway obstruction Bronchial compression (hilar mass, cardiomegaly) Endobronchial obstruction with air trapping (foreign body, tumor) Obliterative bronchiolitis Swyer-James syndrome Pulmonary emphysema (asymmetric) Congenital lobar emphysema Pneumatocele  Pulmonary vascular cause Pulmonary embolism Pulmonary artery hypoplasia

 lack of an identifiable pulmonary artery.  enlarged intercostal arteries serving as collateral vessels to the lung  marked volume loss in the lung.  The pleural surface appears beaded because of the presence of prominent intercostal arteries serving as collateral vessels.  presence of smaller than usual branches of the inferior pulmonary vein compared with the normal-sized other side inferior pulmonary vein.  Pulmonary plethora on the other side.  High resolution CT scanning can evaluate the presence of bronchiectasis in cases of recurrent bronchopulmonary infections.  Pulmonary hypertension  Angiography remains the gold standard for the diagnosis of pulmonary artery agenesis.  With the development of CT, MRI and magnetic resonance angiographic techniques –it is rarely performed unless embolization is indicated for massive hemoptysis.

 Swyer-James-MacLead (SJM) syndrome should be considered in the differential diagnosis of pulmonary artery agenesis.  Perfusion scintigraphy or pulmonary angiography can be used for the differentiation.  The pulmonary artery is hypoplastic in patients with SJM syndrome, air trapping in expiration and ipsilateral lung perfusion is absent.  On the other hand,pulmonary artery can not be observed in patients with UAPA, but peripherally perfusion can be seen via collaterals.

 13 year old boy  Cough  Mild dyspnea  h/o ?near drowning  Pulmonary infection in early childhood Increased lucency on left side Small hilum on left side compared to right

INSPIRATION EXPIRATION – Increased lucency on left side due to Air trapping with mild mediastinal shift to right

 Hyperlucenct lung(Left)  Air trapping on expiration  Left small hilum  Diminished Left side pulmonary vascularity  Normal lung volume  h/o insult to bronchial tree Ruling out other conditions of diffuse air trapping

VOLUME RENDERED AND CORONAL RECONSTRUCTION - shows small left pulmonary artery. SWYER JAMES/ MACLEOD SYNDROME (UNILATERAL EMPHYSEMA,UNILATERAL LOBAR EMPHYSEMA,UNILATERAL HYPERLUCENT LUN G)

Swyer-James syndrome (McLeod syndrome) unilateral post infectious bronchiolitis obliterans in infancy and early childhood. presence of concentric fibrosis involving the submucosal and peribronchial tissues of terminal and respiratory bronchioles,resulting in bronchial narrowing or obliteration  Radiological features…  Nonspecific  Large lung volume  Small hilum  Increased lung lucency(60%)  Reduced size of peripheral vessels  Central bronchiectasis  HRCT – decreased lung attenuation -- decreased vessel caliber -- air trapping -- bronchiectasis / atelectasis

 Small hemithorax, Ipsilateral displacement of the mediastinum, Absence of the corresponding pulmonary artery, Reticular densities along the pleura and within the lung, - due to systemic collateral circulation,Absent hilar shadow, hyperinflation of the contralateral lung. UNILATERAL ABSENCE OF PULMONARY ARTERY  Unilateral hyperlucency with evidence of air trapping,reduced size of pulmonary vessels,small hilum,bronchiectasis and history of some insult to the bronchial tree during early childhood SWYER JAMES SYNDROME