Radiology of Selected Diseases (Part 1) PDF

Radiology of Selected Diseases (Part 1)  Table of contents 01 Chest Wall Diseases. 02 Pleural Diseases. 03 Pulmonary Diseases. 04 Airway diseases. Chest wall diseases Rib fractures: -Due to trauma and can cause life threatening complications. -X-ray: -It shows d...

Radiology of Selected Diseases (Part 1)  Table of contents 01 Chest Wall Diseases. 02 Pleural Diseases. 03 Pulmonary Diseases. 04 Airway diseases. Chest wall diseases Rib fractures: -Due to trauma and can cause life threatening complications. -X-ray: -It shows discontinuity of the rib cortex and may miss up to 50%of rib fractures. Chest wall diseases CT: -More sensitive than plain radiography (x-ray) for the detection of rib fractures.  Chest wall diseases 2-Pectus Excavatum( funnel chest): -Congenital chest wall deformity characterized by concave depression of the sternum, resulting in cosmetic and radiographic alterations. -X-ray: -Blurring of right heart border (PA/AP film). -Increased density of the inferomedial lung zone. -Horizontal posterior ribs. -Vertical anterior ribs (heart-shaped). -Displacement of heart towards the left. -Obliteration of the descending aortic interface. Chest wall diseases CT: The diagnosis is obvious on CT with the degree of deformity and mediastinal shift often dramatic. -The Haller index (HI) (maximal transverse diameter/narrowest AP length of chest) is used to assess severity of incursion of the sternum into the mediastinum. Pleural diseases 1-Pleural effusion : -Abnormal accumulations of fluid within the pleural space. -May result from a variety of pathological processes which overcome the pleura's ability to reabsorb fluid. Plain radiography: -Blunting of the costophrenic angle. -Blunting of the cardiophrenic angle. -Fluid within the horizontal or oblique fissures. -With large volume effusions, mediastinal shift occurs away from the effusion. -If coexistent collapse dominates, mediastinal shift may occur towards the effusion). Pleural diseases CT: -Excellent at detecting small amounts of fluid. -Also able to identify the underlying intrathoracic causes (e.g. malignant pleural deposits or primary lung neoplasms) as well as subdiaphragmatic diseases (e.g.subdiaphragmatic abscess). Pleural diseases Ultrasound: Detection of small amounts of pleural locular fluid, with positive identification of amounts as small as 3 -5 mL. X-ray: -Detecting volumes above 50 mL of liquid. - Ultrasound allows an easy differentiation of loculated pleural fluid and thickened pleura. pleural - Effective fluid thoracocentesis in guiding and thickened even in small fluid collections. Pleural diseases 2- Pneumothorax: -Presence of gas (air) in the pleural space. -Constantly enlarging---- compression of mediastinal structures, it can be life threatening. Plain radiography: -Visible visceral pleural edge is seen as a very thin, sharp white line. -No lung markings are seen peripheral to this line. -Peripheral space is radiolucent compared to the adjacent lung. -Lung may completely collapse. -Mediastinum should not shift away from the pneumothorax unless a tension pneumothorax is present. -Subcutaneous emphysema &pneumomediastinum may also be present.  Pleural diseases CT: -Lung window: Pneumothorax is very easily identified on CT. -Bullous disease is present, a loculated pneumothorax may appear similar. Pulmonary diseases 1-Lobar pneumonia( non-segmental pneumonia or focal non-segmental pneumonia): -Homogeneous and fibrinosuppurative consolidation of one or more lobes of a lung in response to bacterial pneumonia. Pulmonary diseases Plain radiograph: -Homogeneous opacification in a lobar pattern. -The opacification can be sharply defined at the fissures. -More commonly there is segmental consolidation. -The non-opacified bronchus within a consolidated lobe will result in the appearance of air bronchograms. -Consolidation is not associated with volume loss; however, atelectasis can occur with small airway obstruction. Pulmonary diseases CT: -Appears as a focal dense opacification of the majority of an entire lobe with relative sparing of the large airways. -There may be additional associated areas of ground-glass opacity in a lobar or segmental pattern, likely representing areas of partial involvement or simply atelectasis. Pulmonary diseases 2-Covid 19: -is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). -Definitive diagnosis of COVID-19 requires a positive RT-PCR test. Current best practice advises that CT chest is not used to diagnose COVID-19 but may be helpful in assessing for complications. Plain radiograph: Normal in early/mild disease. Airspace opacities, whether described as consolidation or, less commonly, GGO. The distribution is most often bilateral, peripheral, and lower zone predominant. CT findings Ground-glass opacities (GGO): bilateral, subpleural, peripheral. Crazy paving appearance (GGOs and inter- /intra-lobular septal thickening). Air space consolidation. Bronchovascular thickening in the lesion. Traction bronchiectasis. CORADS Airway diseases 1-Bronchiectasis: -Irreversible abnormal dilatation of the bronchial tree. -It has a variety of underlyingcauses, with a common etiology of chronic inflammation. -High resolutionCT is the most accurate modality for diagnosis. Airway diseases -Subtypes: According to macroscopic morphology, also represent a spectrum of severity : Cylindrical bronchiectasis: o Bronchi have a uniform caliber, do not taper and have parallel walls (tram track sign and signet ring sign) o Commonest form. Varicose bronchiectasis: o Relatively uncommon. o Beaded appearances where dilated bronchi have interspersedsites of relative narrowing. Cystic bronchiectasis: o Severe form with cyst-like bronchi that extend to the pleural surface. o Air-fluid levels are commonly present. Airway diseases Plain radiograph: -Chest x-rays are usually abnormal but are inadequate in the diagnosis or quantification of bronchiectasis. -Tram-track opacities are seen in cylindrical Bronchiectasis. -Air-fluid levels may be seen in cystic bronchiectasis. -There appears to be an increase in bronchovascular markings, and bronchi seen end on may appear as ring shadows. -Pulmonaryvasculature appears ill-defined, thought to represent peribronchovascular fibrosis. Airway diseases CT: A number of features are helpful in diagnosing bronchiectasis : *Bronchus visualized within 1 cm of pleural surface: o Especially true of lung adjacent to costal pleura. o Most helpful sign for early cylindrical change. *Lack of tapering. *Increased bronchoarterial ratio: o Diameter of a bronchus should measure approximately 0.65 -1.0 times that of the adjacent pulmonary artery branch. o Greater than 1.5 indicates bronchiectasis Airway diseases *A number of ancillary findings are also recognized: Bronchial wall thickening: normally wall of bronchus should be less than half the width of the accompanying pulmonary artery branch. Mucoid impaction. Air-trapping and mosaic perfusion. *Signs described on CT include: Tram-track sign. Signet ring sign. String of pearls sign. Cluster of grapes sign. Airway diseases Airway diseases 2- Emphysema: -Abnormal permanent enlargement of the airspaces distal to the terminal bronchioles accompanied by destruction of the alveolar wall and without obvious fibrosis. -Emphysema is one of the entities grouped as chronic obstructive pulmonary disease. -Emphysema is best evaluated on CT. Subtypes: Centrilobular emphysema: 1 It is the most frequent type. 2 Affects the proximal respiratory bronchioles. 3 More in the upper zones. 4 Strongly associated with smoking in a dose-dependent way. Panlobular emphysema: 1 It affects the entire secondary pulmonary lobule. 2 More in the lower zones, matching areas of maximal blood flow. Paraseptal emphysema: 1 Affects the peripheral parts of the secondary pulmonary lobule. 2 Usually located adjacent to the pleural surfaces (including pleural fissures). 3 Associated with smoking, and can lead to the formation of subpleural bullae and spontaneous pneumothorax. Airway diseases Plain radiograph: *Exceptin the case of very advanced disease with bulla formation,chest radiography does not image emphysemadirectly, but suspect the diagnosis. Associated features : Hyperinflation: Vascular changes 1 Flattened hemidiaphragm(s): most 1 Paucity of blood vessels, often reliable sign. distorted. 2 Increased and usually irregular 2 Pulmonary arterial hypertension. radiolucency of the lungs. Pruning of peripheral vessels. 3 Increased retrosternal airspace. Increased caliber of central Increased anteroposterior diameter of the arteries. chest. Right ventricular enlargement. 4 Widely spaced ribs. 5 Sternal bowing. 6 Tenting of the diaphragm. Airway diseases  Airway diseases CT: *Able to discriminate between centrilobular, panlobular, and paraseptal emphysema. 1) Centrilobular emphysema: 1 Predominantlyin the upper zones of each lobe (i.e. apical and posterior segmentsof the upper lobes, and superiorsegment of the lower lobes). 2 Has a patchy distribution. 3 It appears as focal lucencies (emphysematous spaces) which measure up to 1 cm in diameter,located centrally within the secondary pulmonary lobule, often with a central or peripheral dot representing the central bronchovascular bundle. Airway diseases 2) Panlobular emphysema: 1 Predominantly located in the lower lobes. 2 Has a uniform distributionacross parts of the secondary pulmonarylobule. 3) Paraseptal emphysema: 1 Located adjacent to the pleura and septal lines. 2 Peripheral distribution within the secondary pulmonarylobule. 3 The affected lobules are almost always subpleural and demonstrate small focal lucencies up to 10 mm in size. *Any lucency >10 mm should be referred to as subpleural blebs/bullae (synonymous). *In all three subtypes, the emphysematous spaces are not bounded by any visible wall Airway diseases Airway diseases 3-Chronic Obstructive Pulmonary Disease (COPD) -Spectrum of obstructive airway diseases. -It includes two key components: 1- chronic bronchitis-small airways disease. 2-emphysema. Clinical phenotypes: emphysema predominant airways predominant o small airways predominant o large airways predominant mixed  Airway diseases -Plain radiograph: *Findings are non-specific: 1 Increased bronchovascular markings. 2 Cardiomegaly. 3-Emphysema manifests as lung hyperinflation with flattened hemidiaphragms, a small heart, and possible bullous changes. Airway diseases CT: Chronic bronchitis 1-Bronchial wall thickening may be seen in addition to enlarged vessels. 2-Repeated inflammation can lead to scarring with bronchovascular irregularity and fibrosis. Emphysema