الفهرس 
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Abstract
Hemoptysis is the expectoration of blood originating from the tracheobronchial tree or pulmonary parenchyma.
Massive hemoptysis may be defined as bleeding of < 300 mL in 24 hours.
Bronchiectasis and tuberculosis were the most common causes of hemoptysis among Egyptian patients as in any other endemic developing country.
Multi–detector row CT provides extended volume coverage with higher image resolution and even greater scanning speed.
The aims of multi– detector row CT in the evaluation of hemoptysis as threefold: (a) to depict underlying disease with high sensitivity by means of detailed images of the lung parenchyma and mediastinum, and in particular to help detect early carcinoma; (b) to help assess the consequences of hemorrhage into the alveoli and airways, which may cause immediate clinical concerns as well as mask subtle underlying abnormalities; and (c) to provide a detailed ”road map” of the thoracic vasculature by means of twodimensional (2D) Maximum Intensity Projection (MIP) reformatted images and three-dimensional (3D) reconstructed images.
The role of MDCT in patients with hemoptysis to reach a diagnosis and in the depiction and traceability of bronchial and nonbronchial systemic arteries as well as pulmonary arteries.
Multi–detector row CT generates isotropic volumetric high-resolution data, allowing contiguous three dimensional (3D) visualization of the lung parenchyma, with the capacity to create high-quality two-dimensional (2D) and 3D reformatted images.
Two-dimensional reformatted images are now of equal importance with the 2D axial images in diagnosing specific diffuse lung diseases.
Post processing MDCT with high resolution data replaced conventional HRCT in patients with diffuse lung diseases including pulmonary edema, chronic infiltrative lung disease, emphysema, chronic obstructive pulmonary disease diffuse pulmonary hemorrhage, and pneumonitis.
Minimum intensity projection (MinIP) was also applied as postprocessing technique of choice for the detection and characterization of most patterns of diffuse lung disease.
Maximum intensity projection (MIP) allows the detection and characterization of micronodules; the recognition of enlarged pulmonary veins, which is extremely useful in the diagnosis of pulmonary edema and the assessment of mosaic perfusion; and differentiation between perilymphatic, miliary, and centrilobular distribution.
CT angiography was also very helpful in depicting bronchial arteries of ectopic origin.
The presence of bleeding was detected by abnormal CTA findings in the form of (1) ground-glass opacities and/or (2) alveolar consolidation; the latter abnormalities were considered to reflect the filling of the alveolar lumen with blood, and (3) atelectasis, induced by clots obstructing the bronchi. In the absence of alveolar filling, isolated cavitation and/or a mass were considered to be localizing lesions. The other combined findings including enlarged nonbronchial arteries, pleural thickening and parenchymal abnormalities are considered as nonbronchial source of bleeding.
The identification of a non bronchial systemic arterial supply at CT before embolization is important because it is helpful for selecting systemic vessels to be studied and embolized.
CT could replace FOB as the first-line tool of investigation in patients with large to massive hemoptysis.
VB located exactly the stenosis and/or obstruction in addition to underlying extraluminal pathology; it could also delineate the poststenotic or obstructed endoluminal lesions which could not be reached by FOB.
VB may also aid clinicians in visualizing external, nonmucosal compressions on the bronchial wall that cause bronchial stenosis. These compressions may be due to normal anatomic structures, such as the aortic arch or esophagus, or to pathologic structures, such as enlarged lymph nodes, fibrotic masses, and extraluminal tumor.
MDCT can replace FOB as the first line investigation for patients with large or massive hemoptysis where bronchoscopy, rigid or flexible fiberoptic endoscope, is useful in identifying a specific endobronchial site of bleeding, biopsy and bronchoalveolar lavage (BAL) and controlling the airway in patients with catastrophic hemorrhage.