Chest radiographs (CXRs) are the most common imaging investigations undertaken because of their value in evaluating the cardiorespiratory system. They play a vital role in intensive care units for evaluating the critically ill. It is therefore very common for the radiologist to encounter tubes, lines, medical devices and materials on a daily basis. It is important for the interpreting radiologist not only to identify these iatrogenic objects, but also to look for their accurate placement as well as for any complications related to their placement, which may be seen either on the immediate post-procedural CXR or on a follow-up CXR. In this article, we discussed and illustrated the routinely encountered tubes and lines that one may see on a CXR as well as some of their complications. In addition, we also provide a brief overview of other important non-cardiac medical devices and materials that may be seen on CXRs.
Among the various imaging modalities available for assessing the cardiothoracic system, the chest radiograph (CXR) is the most commonly used. In addition, the CXR is very useful in assessing the numerous tubes, lines, medical devices and materials, as well as for identifying any equipment-related complications. The American College of Radiology (ACR) recommends a CXR immediately after the placement of a medical tube, catheter or device, to check for malposition or for intra- or post-procedural-related complications. As any medical device has the potential for coiling, mispositioning, kinking or fracturing and malfunctioning, the complications that may ensue are often not immediately apparent clinically. Hence, it is of utmost importance to identify these on the immediate post-procedural CXR or follow-up CXRs for the physician or surgeon to replace or reposition these devices.
The endotracheal (ET) tube is inserted for maintaining the patency of the airways or to provide airway support. The accurate positioning of the ET tube is assessed by calculating the distance of the tip of the ET tube from the carina. An ideal position would be 5 cm above the carina (
(a) Magnified chest radiograph showing an accurately placed endotracheal tube with its distal end (arrow) located above the carina. Other lines and tubes visualised are the right internal jugular vein central venous catheter (star) and the nasogastric tube (arrow head); (b) chest radiograph showing a malpositioned endotracheal tube with its tip in the right main bronchus (arrow). A central venous catheter is noted in the right atrium (star).
A malpositioned ET tube (
Tracheostomy tubes (
Chest radiograph showing an accurately positioned tracheostomy tube (arrow).
The width of the tube should not exceed two-thirds of the tracheal width, and the cuff should not distend the tracheal wall. Complications associated with tracheostomy tubes include subcutaneous emphysema, haematoma and pneumomediastinum. Granulation tissue formation and fibrosis at the site of the stoma can lead to tracheal stenosis.
Nasogastric (NG) tubes are frequently used for suction of stomach contents, administration of medication and for feeding. The NG tube has multiple side holes and a thin radiopaque marker line along one side, enabling it to be identified on a radiographic study (
(a) Chest radiograph showing an accurately positioned nasogastric tube with its proximal side hole (arrowhead) and tip located beyond the gastroesophageal junction. In addition, an endotracheal tube (black arrow) and a right internal jugular vein central venous catheter (star) are noted on this chest radiograph; (b) a malpositioned Dobhoff tube (white arrow) in the right main bronchus. Additionally, a left central venous catheter (star) is noted with its tip in the superior vena cava.
(a) Chest radiograph showing an intercostal drainage (ICD) tube introduced for pneumothorax; (b) a pigtail catheter (arrow) in the right thorax inserted for pleural effusion. Additionally, a malpositioned right peripherally inserted central venous catheter (PICC) [star] is noted with its tip in the left brachiocephalic vein.
(a) Chest radiograph showing a right central venous catheter (arrow) with its end located in the SVC. In addition, bilateral intercostal drainage tubes (stars) and mediastinal drainage tube (arrow head) are noted; (b) chest radiograph showing a left-sided, peripherally inserted central catheter with its tip (arrow) in the right atrium; (c) a tunnelled right central venous catheter.
Magnified chest radiograph showing a malpositioned right central venous catheter in the left brachiocephalic vein.
Magnified chest radiograph showing a widened superior mediastinum secondary to central venous catheter induced haematoma.
Chest radiograph showing a Swan Ganz or pulmonary artery catheter (white arrow), with its tip in the right pulmonary artery. The other devices on this chest radiograph are an endotracheal tube (black arrow), a mediastinal drainage tube (arrow head) and a prosthetic aortic valve (star).
An intercostal drainage tube, also called tube thoracostomy, is commonly inserted for pneumothorax, haemothorax, pleural effusion, and empyema. It also enables instilling antibiotics (after port pneumonectomy for empyema), fibrinolytics, saline and sclerosing agents (pleurodesis).
Haemostatic packing in the right thorax in a 67-year-old male who underwent pneumonectomy. In addition, visualised are a tracheostomy tube (arrow head), a malpositioned Dobhoff tube (black arrow) in the mid-oesophagus, a right central venous catheter with its tip in the mid-SVC (star) and an intercostal drainage tube (white arrow).
Both anteroposterior (AP) and lateral CXRs are required for optimal assessment of an intercostal drain (ICD) tube. Like the NG tube, an ICD tube also contains side holes that can be identified by the interruption of its radiopaque outline on a CXR. The side holes of the ICD tubes should be in the thoracic cavity and not in the chest wall or outside the chest. Some of the complications associated with ICD tubes that may be seen on CXRs include: malpositioning (commonest complication), tube kinking, subcutaneous emphysema, pneumothorax and retained catheter fragment.
Chest radiograph showing heavily calcified breast implants obscuring the lung bases.
(a) Frontal radiograph of the head and neck of a typical shunt series showing the proximal catheter (arrow) in the right lateral ventricle; (b) lateral radiograph of the head and neck of a typical shunt series showing the proximal catheter (arrow) in the lateral ventricle; (c) chest radiograph of a typical (ventriculoatrial) shunt series showing the distal catheter (arrow) terminating at the cavoatrial junction (star) and (d) magnified image of an abdominal radiograph showing an abandoned ventriculoperitoneal shunt catheter in the pelvis (arrow).
A central venous catheter (CVC), also known as a central venous pressure (CVP) catheter or a central catheter or line, is a catheter (
Most clinicians prefer the CVC tip to be positioned at or just above the cavoatrial junction. As the cavoatrial junction may be difficult to identify on a CXR, the most commonly used and reproducible landmark is two vertebral body levels below the carina. An alternative landmark would be the reflection of the SVC contour with the right heart border and the point where the bronchus intermedius intersects the right heartborder.
A summary of the various central venous catheters, potential contraindications and complications.
Type of line | Site of insertion | Duration | Use | Potential contraindications | Complications |
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Non-tunnelled | Internal jugular vein, subclavian vein, axillary vein, femoral vein | Short term (several days to 3 weeks) | Difficult intravenous access; infusion of irritant drugs, vasopressors, inotropes; short-term total parenteral nutrition | Coagulopathy | |
Peripherally inserted | Basilic vein, cephalic vein, brachial vein | Medium term (weeks to months) | Difficult intravenous access; blood sampling; medium-term drug administration (for example, antibiotics); administration of irritant drugs (such as chemotherapy); total parenteral nutrition | Thrombocytopenia | |
Tunnelled (for example, Hickmann, Groshong) | Internal jugular vein, subclavian vein | Long term (months to years) | Long-term administration of irritant drugs (such as chemotherapy) | Ipsilateral haemothorax or pneumothorax | |
Totally implantable (such as implanted port) | Internal jugular vein, subclavian vein | Long term (months to years) | Long-term intermittent access (for example, regular hospital admissions with poor intravenous access); administration of irritant drugs (such as chemotherapy) | Vessel thrombosis, stenosis or disruption | |
- | - | - | - | Infection overlying insertion site | - |
- | - | - | - | Ipsilateral indwelling central vascular devices | - |
Pulmonary artery catheterisation involves inserting a catheter (Swan Ganz) through a central vein (mostly the subclavian or jugular vein and rarely through a femoral vein) into the right heart and finally into the pulmonary artery (
A vagal nerve stimulator, its electrode (arrow) and pulse generator (star) in a 10-year-old male patient diagnosed with Lennox-Gastaut syndrome and suffering from refractory seizures.
Medical devices and materials such as electrocardiogram (ECG) leads, ventilator tubing, syringes, clamps, temperature sensors, post-coronary artery bypass grafting (CABG) sternotomy wires, surgical clips, orthopaedic implants, gown snaps, etc. are commonly seen on CXRs. Because of its limited scope, we have not included cardiac devices in this article. However, there are other non-cardiac iatrogenic objects that can be seen on CXRs and these have been summarised in
A list of some of the other non-cardiac iatrogenic materials and medical devices that may be seen on chest radiographs.
Non-cardiac iatrogenic materials and medical devices | Their uses and how to assess them |
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Haemostatic agents | Use: to control intraoperative bleeding by forming artificial clots and facilitating platelet aggregation. |
As these materials can mimic an abscess or even a tumour on imaging, radiologists need to be aware of their appearance on CXRs ( |
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Breast implants | Use: mainly for cosmetic purposes, breast reconstruction post-mastectomy and for correction of congenital malformations. |
Radiologists need to aware of their appearance on CXR ( |
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Cerebrospinal fluid (CSF) shunts | Use: mainly placed for managing hydrocephalus. |
A basic CSF shunt comprises a proximal catheter, reservoir, valve and a distal catheter. The proximal catheter is placed in one of the lateral ventricles, and it exits through a burr hole, connected to the reservoir in the subcutaneous tissue. The distal catheter can theoretically be placed in any fluid reabsorbing body cavity. Shunts are commonly placed in the peritoneum (ventriculoperitoneal shunt), right atrium (ventriculoatrial shunt) or pleural space (ventriculopleural shunt). Ventriculoperitoneal (VP) shunts are by far the most preferred as they are associated with fewer complications. | |
A standard radiographic series (‘shunt series’) includes a frontal and lateral radiograph of the head and neck and frontal radiographs of the chest and abdomen to evaluate the entire shunt ( |
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Vagal nerve stimulator (VNS) | It is the only approved implantable device for long-term management of seizure in patients who are refractory to antiepileptic therapy. |
The device is battery operated and resembles a pacemaker. The device is implanted under the left clavicle. However, unlike a pacemaker or ICD, the lead is positioned in the neck to stimulate the left vagal nerve in the carotid sheath ( |
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Radiologists need to be aware of these devices so as to not get confused with a pacemaker or ICD. |
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Other extra cardiac stimulators that may be seen on CXRs include deep brain stimulation (DBS) devices, bone, diaphragmatic and spinal cord stimulators. |
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Non-coronary or non-cardiac metallic stents | Uses: for non-coronary vascular applications (e.g. thoracic aorta aneurysm repair [ |
As most of the stents are metallic, they are visible on radiographs. It is important that radiologists identify these devices appropriately and evaluate the radiographs for potential complications such as a stent fracture or migration. |
Endovascular stent graft in the thoracic aorta of a 75-year-old man, placed after aneurysm repair.
Oesophageal stent inserted in a 68-year-old female with dysphagia secondary to oesophageal carcinoma.
Transjugular intrahepatic portosystemic shunt stent in a 62-year-old female patient with portal hypertension.
A variety of tubes, lines and medical devices may be seen on CXRs of patients admitted in a hospital. A thorough evaluation of these CXRs is important. Radiologists need to recognise these medical materials, assess them for accurate placement and look for abnormal radiographic presentations, which will enable them to inform the relevant physician or surgeon in a timely manner and help avoid potential consequences.
The authors have declared that no competing interests exist.
R.P.M. was the project leader and wrote the manuscript. T.A. was the lead subject authority, supervised manuscript writing and helped acquire the images. V.P. did supervision of manuscript and helped acquire the images. G.L. did supervision of manuscript and helped acquire the images.
All ethical considerations have been taken into account. No patient identity or patient information has been revealed.
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Data sharing is not applicable to this article as no new data were created or analysed in this study.
The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of any affiliated agency of the authors.