Thoracic radiology

It is an examination performed with the use of X-rays to distinguish the major structures of the chest, namely the heart, vessels, lungs, and bones.

Main indications
Chest X-ray is useful, as an initial evaluation, if one suspects a:

• Infectious lung pathology (e.g., bronchopneumonia).
• Pathology of the pleura (e.g., effusion).
• Pathology of the interstitium (e.g., pulmonary fibrosis).
• Cardiac pathology (e.g., heart failure).
• Neoplastic pathology (e.g., lung, pleural, or mediastinal cancer).

If an abnormality is found, further investigation with CT examination of the chest may be necessary.

How it is performed
Appropriately positioned in front of the sensitive screen of the X-ray machine, the patient should take a deep breath, holding air and standing still for a few seconds. During this short interval, the X-ray will be performed.

Required preparation
Chest radiography does not require any specific preparation.

MRI does not require the use of X-rays: images of the human body are obtained using magnetic fields and radio waves.

Main indications
MRI of the chest finds an indication for the study of the heart (on indication of the cardiologist) or as an in-depth study after a CT scan of the chest, to better define a thoracic pathology, which affects the mediastinum (central part of the thoracic cavity where the heart and large vessels are located) or the lungs or the chest wall. There is an indication therefore in case of:

• Suspected neoplasm of the mediastinum.
• Need for better preoperative definition of a lung tumor.
• Pathology of the large vessels and heart.

How it is performed.
To perform the examination, the patient must lie supine on the MRI table, where a stand will be placed above the chest, containing the radiofrequency coils necessary to acquire the signal that will then form the images. During image acquisition there will be background noise, which will be attenuated by the use of special headphones. The examination typically lasts 20-30 min.

Preparation needed
It is necessary to check for items that prevent the MRI from being performed. In fact, it is important to know if the patient has a pace-maker/defibrillator, an insulin pump or other devices whose compatibility with the MRI needs to be checked, and if he or she has undergone previous surgery with placement of cardiac/vascular stents, heart valves, brain clips, metal orthopedic prostheses, or if he or she has body metal shrapnel and tattoos.
If you have a known allergy to the contrast medium, you should inform your attending physician, who will then agree with the radiologist on the next course of action.
In case of known kidney disease, the attending physician may request a blood test to check renal function i.e., the patient's ability to eliminate the paramagnetic contrast agent.

A CT scan of the chest is an examination that uses X-rays to visualize and study anatomical structures in considerably greater detail than an X-ray. It is generally performed as a Level II investigation after a chest X-ray.

Principal indications
CT scan of the chest is mainly performed for:

• Study of a neoplastic pathology of the lungs, pleura, and mediastinum.
• Study of a pathology of the lung parenchyma (tissue) (e.g., interstitial disease, bronchiectasis).

How it is performed
To perform the examination, the patient must lie supine on the couch with arms raised above the head. During the examination, the patient's cooperation in performing the respiratory acts (inhale-apnea-exhale) is requested. In specific cases it requires the use of an iodinated contrast agent (i.e., a substance visible with X-rays) introduced through a peripheral venous access. The examination usually lasts 5 min.

Preparation required
If contrast medium is to be administered, it is necessary to undergo a blood test (creatinine) to check renal function, i.e., the patient's ability to eliminate the contrast medium. Contrast medium injection may be contraindicated in case of severe renal insufficiency or previous moderate/severe allergic reaction to iodinated contrast medium.
In case of a known allergy, it is necessary to inform one's attending physician, who will then agree with the radiologist on the next course of action, including considering the possibility of choosing an alternative examination.

Ultrasound is an examination based on the use of ultrasound that allows the morphological and structural study of organs and tissues.

Main indications
Ultrasonography finds indication in the study of pathologies of the pleura, such as the presence of fluid in the thoracic cavity. Ultrasound can play a role in guiding nonvascular interventional procedures, such as drainage of a pleural effusion or biopsies on chest wall structures and lesions of the lung. In selected cases, it is useful for the diagnosis of pneumothorax (i.e., air leaking from the lung into the pleural cavity).

How it is performed
At the patient's side lying on the couch (sitting position is required for some procedures), the radiologist will use the ultrasound probe, sliding it over the part of the chest to be examined. The duration of the examination is generally 15 minutes.

Preparation needed
No specific preparation is required.