Radiological Category Thoracic Chest Principal Modality 1 General

Radiological Category: Thoracic Chest Principal Modality (1): General Radiography Principal Modality (2): CT Case Report #0464 Submitted by: Bhumi Rawal, M. D. Faculty reviewer: Emma Ferguson, M. D. Date accepted: 15 February 2008

Case History 39 year old female with acute shortness of breath. Patient reports no history of trauma.

Radiological Presentations

Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Right pulmonary mass • Large right pleural effusion • Pneumonia • Total right lung collapse • Diaphragmatic hernia

Findings and Differentials Findings: There is near complete opacification of the right hemithorax with obscuration of the right heart border and right hemidiaphragm. The mediastinum is shifted to the left. The tip of a right subclavian central venous catheter projects over the junction of the right brachiocephalic vein and the superior vena cava. Differentials: • Right pleural effusion • Right pleural tumor • Pneumonia • Right pulmonary mass • Diaphragmatic hernia

Discussion The differential diagnosis for complete hemithorax opacification includes: – Pleural processes (pleural effusion, pleural tumors including mesothelioma, fibrothorax) – Atelectasis (usually due to a bronchial carcinoma) – Infectious, inflammatory, or neoplastic infiltration of a lung – Pulmonary agenesis – Pneumonectomy – Diaphragmatic hernia To narrow the differential, determine the volume of the opaque hemithorax: – Normal • Pneumia, neoplastic infiltration of a lung, atelectasis in combination with pleural effusion – Increased (signs include contralateral mediastinal shift, widened intercostal spaces, and hemidiaphragm depression) • Pleural effusion, pleural tumors, diaphragmatic hernia – Decreased (signs include ipsilateral mediastinal shift, narrowed intercostal spaces, and hemidiaphragm elevation) • Atelectasis, pulmonary agenesis, pneumonectomy, restrictive pleural processes such as fibrothorax

Discussion In this case, the mediastinum is shifted contralaterally, representing increased volume of the right hemithorax. Pneumonia and lung masses rarely cause increased hemithorax volume. Thus, the differential would include pleural effusion, pleural tumors, and diaphragmatic hernia. There is no bowel pattern in the opacified hemithorax to suggest diaphragmatic hernia. Comparison with the previous radiograph obtained two days earlier, after line placement, indicates an acute process. Thus, pleural tumors are excluded. Given the recent line placement, line complication with vascular injury and hemothorax must be considered.

Discussion CT following contrast administration through the subclavian central venous catheter demonstrated a large right pleural effusion with layering contrast, indicating contrast extravasation into the pleural space.

Discussion Injection through the central venous catheter demonstrates contrast extravasation into the pleural space. Injection into the subclavian vein does not demonstrate contrast extravasation. These findings indicate that there is extravascular placement of the catheter. No venous perforation was identified.

Discussion Central venous catheter-related complications occur in approximately 5 -20% of cases. The majority of these are related to insertion and positioning. Complications of central venous catheter placement include: Pneumothorax (up to 5%) Arterial puncture, with possible resultant extrapleural hematoma or pseudoaneurysm Extravascular placement of catheter Ectopic infusion of fluid into the mediastinal or pleural space Vascular or cardiac perforation Catheter fragmentation with subsequent central venous embolization Infections, early or late Venous thrombosis or catheter occlusion

Diagnosis Extravascular placement of central venous catheter with resultant large right pleural effusion

References Fisher KL, Leung AN. Radiographic Appearance of Central Venous Catheters. AJR 1996; 166: 329 -337 Lange S, Walsh G. Radiology of Chest Diseases, 2 nd ed. Stuttgart: Thieme, 1998: 281 -284 Mc. Loud TC. Thoracic Radiology: The Requisites. St. Louis, MO: Mosby, 1998: 155 -159