Cystic Fibrosis is a genetic condition that affects the regulation of how cells move salt and water around. This means that the body’s mucus becomes very sticky and thick. This mucus builds up in the lungs, airways, and digestive system, affecting breathing and digestion for people with CF. (1)

We mainly image CF patients in CT to monitor their lungs. This helps to track disease progression and adjust the patients treatment. 

Within the lungs, mucus build up can cause risks for chronic and repetitive bacterial infections and increased inflammation. This leads to the weakening of the bronchial walls and a condition called bronchiectasis. 

Scanning note: Patients who have CF cannot come into contact with the mucus of other CF patients. It is important that we don't book CF patients close together, wear protective precautions PPE and that we clean the room between patients. 

Is the abnormal distention of the bronchial tree caused by damage to the epithelial layers of the tissue. This is usually a result of chronic inflammation and/or the obstruction of the bronchial tree. 

Signs of bronchiectasis on CT include:

• Visualisation of bronchi within 1cm of pleura (usually too small to see)

• Lack of tapering of the bronchi the more distal it becomes from the carina

• Bronchi adjacent to pulmonary arteries should be no more than the same size. If the exceed the size by 1.5 times it is indicative of bronchiectasis (3)

Other signs include:

• Air trapping distal will often occur as the diseased bronchus will be less efficient at expelling air

• Bronchial wall thickening from inflammation and mucus build up

<-- See all of these in the image across

Can be pathological or can be caused by poor inspiratory effort.

<--  In the top image you can see atelectasis in the posterior aspect of the lung shown by thickened and dense lung tissue. This can make it difficult to interpret pathology hidden within this collapsed tissue (mass's, fluid and nodules)

<-- In this image, the patient has provided a larger inspiration and the atelectasis has cleared mostly on the right and completely on the left. 

<-- In this image the lungs are fully inflated showing no areas of collapse. It shows the importance of obtaining good inspiratory efforts for all patients when assessing the lung tissue. 

Note for scanning: This is why for patients who cannot stay still and/or provide a good inspiration, we cannot perform chest CT imaging under sedation. There lungs would not be well seen as they would be still but only in a natural breathing cycle. We must perform it using GA, as the anaesthetist can provide us with good inspiratory breath holds to better evaluate the lung tissue. 

Lung nodules are small opacities (<30mm) within the lung tissue. Nodules are generally homogenous and well defined. 

There are multiple reasons they form such as cancer, infection, scarring and lymph nodes. Once seen on CT, these patient will require follow up CT imaging to monitor size and growth of the nodules. As we are performing this regularly, we can often perform these scans at a lower dose, providing the nodules are staying consistent in size

(4)