Random_19 Flashcards
endemic
vs
epidemic
endemic - found in a certain geographic region or in a specific race of people
epidemic - a disease that is widespread, affecting an “atypically large number of individuals within a population, community, or region at the same time,”
Congenital lobar emphysema.
A, Radiograph obtained at 1 day of age shows diffuse lucency and enlargement
of left upper lobe (arrows). B, CT scan shows hyperlucent and enlarged left upper lobe with asymmetric attenuation of vascular structures and increased space between interstitial septa.
Congenital lobar emphysema
- over-expansion of alveoli
- most common site: LUL
- CXR:
- hyperlucent, hyperexpanded lobe
- initially may appear to be a soft tissue density due to retained fetal lung fluid. It then resolves and is replaced by progressive hyperlucency
- CT:
- air is in the alveoli
- interstitial septa and bronchovascular bundles pushed to the periphery
- air spaces are larger than adjacent normal lung
- pulmonary vessels are attenuated
- Rx: lobectomy
Congenital pulmonary airway malformation / CPAM
Congenital cystic adenomatoid malformation / CCAM
Figure:
Type 1 congenital cystic adenomatoid malformation. A, Coronal fetal MR image shows hyperexpanded, high-signal lesion (arrows) in left lobe. Note lower signal in normal right lung (R). B, Chest radiograph after birth shows lucent, multicystic lesion in left lung with rightward mediastinal shift. C, CT soon after birth shows large, lucent, multicystic lesion in left lung.
Congenital pulmonary airway malformation / CPAM
- majority are detected prenatally
- majority are present with resp distress at birth
- communicate with the bronchial tree at birth and fill with air within the first hours of life
- NO lobar predilection
- vs congenital lobar emphysema (LUL most common)
- 3 types
- Type 1 - >2cm large cysts
- Type 2 - mixed
- Type 3 - <5mm microcysts, solid appearing
- management
- symptomatic - surgical resection
- asymptomatic - controversial. ? risk of infection and malignancy
Pulmonary sequestration
Pulmonary sequestration
- most commonly presents with recurrent pneumonia, usually in late childhood
- do not communicate with the bronchial tree unless they become infected - usually appear as radiopaque mass or resp distress in newborn period
- most common location - LLL
Lobar predilection for:
- CPAM
- congenital lobar emphysema
- pulmonary sequestration
- PVPVR
Lobar predilection for:
- CPAM- NO lobar predilection
- congenital lobar emphysema - LUL
- pulmonary sequestration- LLL
- PVPVR - RUL
Bronchogenic cyst
Bronchogenic cyst
- can occur in the middle mediastinum (most common) or within the lung parenchyma (mainly perihilar in location)
- almost always solitary lesions
- common compress the distal trachea and bronchi
- do NOT contain air until they become infected
- well-defined soft tissue attenuation or cystic masses
Hyperinflation in an infant are much more easily evaluated on the lateral than on the frontal views
Hyperinflation in an infant are much more easily evaluated on the lateral than on the frontal views
Viral lower respiratory infection in a young child.
A, Frontal view shows increased perihilar markings and bandlike density (arrow) in right middle lobe, representing subsegmental atelectasis. B, Lateral view better shows marked hyperinflation with flattened hemidiaphragms, increased anterior-to-posterior diameter of the chest (chest is wider than it is tall), and barrel shape of chest. Increased perihilar markings make hila appear prominent.
Viral pneumonia
- Viral infections affect the airways, causing inflammation of the small airways and peribronchial edema.
- This peribronchial edema appears on radiography as increased peribronchial opacities—symmetric course markings that radiate
from the hila into the lung. - The central portions of the lungs appear to be ‘‘dirty’’ or ‘‘busy.’’ It is one
of the most subjective findings in radiology. - In addition, the combination of the bronchial wall edema, narrowed airway lumen, and necrotic debris and mucus in the airway leads
to small airway occlusion. This results in both hyperinflation and areas of subsegmental atelectasis.
The common causal agents of lower respiratory
tract infections in children vary greatly
with age.
- In all age groups, viral infections are much more common than bacterial infections.
- preschool (4/12 - 5y/o) - 95% viral
- school-age (6y/o - 16y/o) - most still viral; but increased streptococcal pneumonia and mycoplasma pneumonia
*
Bacterial pneumonia.
Radiograph shows focal lung consolidation (P) in lateral aspect of right lower lobe, consistent with bacterial pneumonia.
Bacterial pneumonia
- In contrast to the airway involvement in viral pneumonia, bacterial pneumonia occurs secondary to inhalation of the infectious agent into the air spaces.
- vs. viral pneumonia - affecting airways
- resultant progressive development of inflammatory exudate and edema within the acini, resulting in consolidation of the air spaces.
- air bronchograms
- a propensity for pneumonia to appear ‘‘round’’ in younger children
- more common in children younger than 8 years of age
- most often caused by S. pneumoniae
- related to poor development of pathways of collateral ventilation
- tends to be solitary and occurs more commonly posteriorly and
in the lower lobes - correlate clinically for infectious symptoms, and child should be treated with antibiotics and the chest radiograph repeated. It is best to avoid unnecessary CT examination in this clinical scenario.
- when a round opacity is seen in a child older than 8 years of age, other pathology should be suspected.
Figure:
Round pneumonia. Radiograph shows rounded opacity overlying the left hilum. This is the location of the superior segment of the left lower lobe.
Ultrasound may play a more useful role than CT in the early evaluation of parapneumonic effusions. It is not uncommon for ultrasound to show multiple septations and in the same case to show no evidence of septations on CT. We currently advocate ultrasound, rather than CT or decubitus radiographs, in the primary evaluation of parapneumonic effusions.
Figure:
Parapneumonic effusion (empyema) evaluated by CT and ultrasound. A, CT shows left parapneumonic effusion. There are no findings to suggest empyema on CT. There are no septations seen by CT, which is typical. B, Ultrasound shows consolidated lung (L) with surrounding band of pleural fluid (arrows). Note multiple echogenic septations consistent with complex effusion.
Ultrasound may play a more useful role than CT in the early evaluation of parapneumonic effusions. It is not uncommon for ultrasound to show multiple septations and in the same case to show no evidence of septations on CT. We currently advocate ultrasound, rather than CT or decubitus radiographs, in the primary evaluation of parapneumonic effusions.
Cavitary necrosis with bronchopulmonary fistula
formation.
CTshows consolidation of the right lung. Portions of the lung demonstrate cavitary necrosis (arrows). There are also areas of consolidated lung that enhance (L) and are not compromised. There is a pleural effusion (P) that contains both air and fluid. There is thickening and enhancement of the parietal pleura (white arrowhead) and thickening of the extrapleural space (black arrowhead), both findings that claimed to be suggestive of empyema rather than transudative effusion but were shown to be inaccurate.
Most common sequelae of acute pneumonia in children
Figure:
Chronic complications related to recurrent pneumonias. CT shows multiple round, soft tissue density lesions in medial right lower lobe (arrows) consistent with bronchiectasis with mucus plugging. In the left lower lobe, there is an area of air trapping (arrowheads) consistent with obliterative bronchiolitis. This area remained hyperlucent on expiratory images.
Most common sequelae of acute pneumonia in children
- bronchiectasis
- Swyer-James syndrome
- virus-induced necrotizing bronchiolitis
- oblieterative bronchiolitis
- hyperlucent and enlarged lung with air trapping; less prominent pulmonary vasculature
when lung consolidation is seen with associated lymphadenopathy or effusion in a child who is not acutely ill, there should be a high suspicion for tuberculosis. Most of the cases of pulmonary tuberculosis that I have seen have demonstrated unilateral hilar lymphadenopathy.
when lung consolidation is seen with associated lymphadenopathy or effusion in a child who is not acutely ill, there should be a high suspicion for tuberculosis. Most of the cases of pulmonary tuberculosis that I have seen have demonstrated unilateral hilar lymphadenopathy.
Tuberculosis in a 7-year-old boy.
A and B, Frontal and lateral radiographs of the chest demonstrate a left hilar mass (arrows) consistent with unilateral lymphadenopathy. There is also left upper lobe collapse. Note displaced major fissure on lateral view (arrowheads).
Fungal infection
Figure:
Fungal pneumonia in child after bone marrow transplantation for aplastic anemia. A, CT shows poorly defined nodules and associated ground-glass opacity. B, A CT taken earlier shows clear lungs. Note the striking change since this baseline study.
Fungal infection
The hallmark CT finding indicating fungal infection is the presence of nodules.
They are commonly clustered and may exhibit poorly defined margins, cavitation, or a surrounding halo that has the opacity of ground glass.
Figure:
Histoplasmosis infection. CT shows multiple nodules bilaterally. There is a biopsy site on the left, anteriorly.
Acute chest syndrome in a 6-year-old boy with
sickle cell anemia.
A, Chest radiograph obtained at admission shows low lung volumes and minimal focal opacity within the left lower lobe. B, Chest radiograph obtained 1 day later shows consolidation of a large portion of the left lung. C, Chest radiograph obtained 2 days after A shows complete left lung opacification.
Although it is debated whether the cause of such episodes is more often related to infection or infarction, many believe the lung opacities are related to rib infarction, splinting, and subsequent areas of atelectasis.
Radiography often shows segmental to lobar pulmonary opacities but can also be normal. There can be an associated increase in cardiomegaly. Bone scans may show rib infarcts.
Cystic fibrosis.
A, Radiograph shows areas of bronchial wall thickening and bronchiectasis, most prominent in the right upper lobe. B, High-resolution CT shows diffuse bronchiectasis and bronchial wall thickening within the upper lobes. There are also multiple areas of poorly defined opacities, particularly in the peripheral portions of the left upper lobe. These have a tree-in-bud appearance.
Cystic fibrosis
Imaging findings:
hyperinflation, increased peribronchial markings, mucus plugging, and bronchiectasis.
The hilar areas can become prominent because of a combination of lymphadenopathy secondary to the chronic inflammation and enlarged central pulmonary arteries related to the development of pulmonary arterial hypertension.
Lung contusion and laceration after a motor vehicle
accident.
CT shows characteristic findings of contusion on the left, including posterior location, crescent shape, nonsegmental distribution, and subpleural sparing (arrows). On the right, there is large pneumothorax (PTX) and consolidation of lung with an air-filled cyst (arrow) consistent with lung laceration.
Thymic cysts
vs
Thymic enlargement and calcifications
- Thymic cysts - associated with AIDS
- Thymic enlargement and calcificatins - associated with Langerhan cell histiocytosis
Figure:
Enlarged thymus with calcifications in child with Langerhans cell histiocytosis. CT shows prominent thymus with high-attenuation calcifications.
Pediatric thymus
“Sail sign” vs “Spinnaker sail sign”
Figure:
Normal, prominent thymus with ‘‘sail’’ sign. Radiograph shows prominent but normal thymus with rightward triangular extension (arrow).
Figure:
‘‘Spinnaker sail sign’’ in child with pneumomediastinum. Radiograph shows thymus (arrows) lifted off of mediastinum by air in mediastinum. The uplifted thymus resembles a spinnaker sail.
Lymphoma.
A, Frontal radiograph shows marked enlargement of superior mediastinum and associated right pleural effusion. B, Lateral radiograph shows posterior displacement, compression, and poor visualization of the trachea (arrow), further supporting the presence of an abnormal mediastinal mass. C, CT shows large anterior mediastinal mass (M) with compression and posterior displacement of trachea (arrow) and compression of the superior vena cava (arrowhead). Note right pleural effusion. D, Coronal CT again shows mass (M) and compression of superior vena cava (arrow).
NOTE: normal thymus will NOT cause mass effect on the adjacent structures!!
Lymphoma with pericardial effusion.
CT image from level of heart in a child with an anterior mediastinal mass; on more superior images shows extension of lymphoma mass (L) inferiorly. Note adjacent pericardial fluid (arrowheads) and bilateral pleural fluid (arrows).
Teratoma.
CT shows anterior mediastinal mass (M) that is of fat attenuation.
Neuroblastoma.
A, Radiograph shows a large mass in right upper hemithorax. There is widening (W) of the interspace between the right third and fourth ribs and erosion of the undersurface of the right third rib (arrow). The rib splaying and erosion document chest wall involvement and the posterior nature of the tumor. B, CT shows large mass (M) with compression of the trachea (arrow). The mass is so large it extends from anterior to posterior chest walls. C, MIBG scan shows avid uptake of radiotracer within the mass (arrows), consistent with a neurogenic tumor. D, Photograph taken during surgical resection shows a mass (M) arising
from the posterior chest.
