The chest CT or CT angiography (CTA) are well known as comprehensive,
non-invasive methods for evaluating hemoptysis,
including detection of the primary causes of hemoptysis,
determining the site of active bleeding,
and planning surgery or bronchial arterial embolism (BAE) [1,
5].
Hemoptysis has multiple causes categorized under parenchymal,
airway,
vascular diseases and coagulopathies.
Usually fiber optic bronchoscopy (FOB) is not modality of choice in cases of hemoptysis less than 300 ml.
in 24 h.
Moreover,
CT evaluation is essential when FOB evaluation is difficult or can be dangerous,
especially in emergencies [2].
Bleeding may originate from lungs or systemic vessels [3,
6].
Bleeding from the small vessels usually causes a focal or diffuse alveolar hemorrhage and is mainly due to immunologic,
vasculitic,
cardiovascular,
and coagulation causes.
Causes of bleeding from the large pulmonary or systemic vessels include infectious (Fig.
1,
2),
cardiovascular,
congenital,
neoplastic and vasculitic diseases (Fig.12,
13).
However,
the most frequent diseases causing hemoptysis are bronchiectasis (Fig.
5,
6),
tuberculosis (Fig.11),
fungal infections (Fig.3,
4),
and cancer (Fig.7,
8,
10) [4,
7].
Aortic aneurism is a rare but life – threatening reason of massive hemoptysis (Fig.14) [3,
5].
Role of CT on the hemoptysis
MDCT represents a noninvasive and highly useful imaging tool in the clinical context of hemoptysis and allows a comprehensive evaluation of the lung parenchyma,
airways,
and thoracic vessels by using contrast material [5,
6].
MDCT may identify the bleeding site in 63% to 100% of patients with hemoptysis and can uncover the potential underlying causes of bleeding,
such as bronchiectasis,
pulmonary infections,
lung cancer,
etc.,
being superior to bronchoscopy in this respect.
MDCT also has the advantage of showing distal airways beyond the level of the bronchoscope,
and it has a sensitivity of more than 90% in identifying endobronchial lesions [5-7].
Nevertheless,
there are some limitations in characterizing lesions such as endobronchial blood clots that may mimic a tumor and visualizing an endobronchial process in the presence of acute bleeding filling the bronchial lumen [5].
In these cases bronchoscopy remains an important complementary diagnostic tool (10).
It has been affirmed that the combined use of MDCT and bronchoscopy provides the best accuracy in assessing patients with hemoptysis [6].
Numerous authors have suggested that MDCT should be carried out before eventual bronchoscopy in all patients with hemoptysis [5].