Subsegmental atelectasis is a term used on X-rays and CTs to indicate that a small part of the lung is collapsed or poorly expanded with air. This is often a benign finding that is not responsible for your symptoms.
Subsegmental atelectasis meaning
It means that small part of the lung is airless and collapsed. This is often caused by a small bronchus (tube that carries air to the lungs) is inflamed or blocked by mucus. In rare instances, a growth or tumor can cause subsegmental atelectasis.
The lung is split into 10 segments or parts on each side. By subsegmental, we mean that less then one of those parts is collapsed. It is more serious when an entire segment or more is collapsed.
What causes subsegmental atelectasis?
This can occur because you have been taking more shallow breaths like after surgery. Anything that suppresses the ability to cough can cause atelectasis. Atelectasis can occur when there is something that presses on the lung and does not let it expand fully like fluid, a big lymph node or tumor. A blocked airway or bronchus can cause atelectasis.
Subsegmental atelectasis symptoms
Most subsegmental atelectasis does not have symptoms. The larger and the more extensive the atelectasis is, the more likely a patient will have shortness of breath.
What does subsegmental atelectasis look like?
The appearance of subsegmental atelectasis is that of a thin small white line or white spot that looks like a band. Sometimes it can look more nodular which can then mimic more concerning abnormality.
Bibasilar subsegmental atelectasis
This is perhaps the most common location. Bibasilar means that it is seen at the bottom of both lungs or at the bases of the lower lobes. Subsegmental atelectasis can also be seen on the left or right side. It can also be seen anywhere in the lungs.
Mild subsegmental atelectasis
Mild subsegmental atelectasis is the least severe kind. This may be one or two spots of subsegmental atelectasis. More severe cases will be more extensive and involve both lungs.
Scattered subsegmental atelectasis
This means that the atelectasis is not in one spot in the lung but in multiple spots of the lung.
Subsegmental atelectasis treatment
Many cases will not require treatment. Promoting deep breathing and coughing will help. Relief of airway obstruction. For mucus, this can be done with suctioning or bronchoscopy. Growths or tumors which block the airway may need surgery, radiation or chemotherapy to relieve the blockage.
This is another term that means subsegmental atelectasis. Platelike atelectasis is another term that is used to mean the same thing. These terms often describe subsegmental atelectasis which looks linear on an X-ray. The causes are the same as is the imaging appearance.
Linear subsegmental atelectasis
This is another descriptive term that also includes how the atelectasis looks on imaging. This means it looks like a straight thin white line.
What else can look like subsegmental atelectasis on chest X-ray?
Subsegmental atelectasis can also look like small areas of scarring of the lung. This can be from a prior infection or other insult to the lung.
Sometimes subsegmental atelectasis can look more rounded or irregular. In these cases, follow up or further testing may be needed.
Can subsegmental atelectasis be serious?
Usually not if it is a small subsegmental area of atelectasis. The larger the atelectasis the more likely it is to cause symptoms.
In rare cases, a portion of a lung can collapse when a tumor blocks the tube or bronchus which lets air pass to it. A CT scan or bronchoscopy procedure may be needed for diagnosis.
Subsegmental atelectasis summary
Subsegmental atelectasis is a collapse of a small part of the lung. It is benign and asymptomatic most of the time. It is often from shallow breathing or suppressed cough. Rarely, this can result from something pressing on the lung or an obstructed bronchus. Treatment is usually not required, but can include deep breathing and relief of airway obstruction.