B&H Flashcards
How to evaluate proper CXR technique?
PRIM
- penetration
- rotation
- inspiration
- motion
Utility of lateral decubitus CXR
- detect small pleural effusion on ispilateral side (5ml)
- detect small PTX on contralateral side (15ml)
- detect the free-flowing nature of pleural effusions
- detect air-trapping in check valve bronchial obstruction in a patient who is unable to cooperate for inspiratory/expiratory CXR
Normal tracheal caliber
- 25 mm in men
- 21 mm in women
- coronal : sagittal = 0.6 : 1.0
- if ratio < 0.6, then saber sheath trachea
- COPD
Maximal thickness of right paratracheal strip and posterior tracheoesophageal stripe?
- right paratracheal stripe < 4mm
- posterior tracheoesophageal stripe < 5mm
Bronchioles
terminal bronchioles –>
respiratory bronchioles –>
alveolar ducts and alveolar sacs
Pulmonary alveolar epithelial cellls
(pneumocytes)
- Type 1 pnemocytes
- 95%
- invisible by light microscope
- incapable of mitosis/repair
- Type 2 pneumocytes
- 5%
- visible by microscpe
- capable of mitosis, produces type 1 pneumocytes
- produces surfactant
Where does the minor fissure projects on a frontal PA CXR?
level of the right 4th rib
Azygos fissure
- due to incomplete migration of the azygos vein to its normal position at the right tracheobronchial angle
- 4 layers of pleura
- 2 visceral
- 2 parietal
Bronchial artery
- Right - 1 - posteriorly from aorta
- Left - 2 - anteriorly from aorta
- 2/3 - drains into the pulmonary venous system via the bronchial veins - small right to left shunt
- 1/3 - drains in to the azygos and hemiazygos systems
Approach to CXR
- Soft tissues
- Bones
- Mediastinum
- Lungs
Convexity to the azygoesophageal recess
- superior third - subcrinal lymph node or mass
- middle third - confluence of right pulmonary veins or the right border of the left atrium
- left atrial dilatation produces double density interface
- inferior third - sliding hiatal hernia
Pectus excavatum
- leftward cardiac displacement
- loss of the interface betwen right heart border and medial right middle lobe
- not to be confused with RML pneumonia
Aortic nipple
left superior intercostal vein
Heart borders on CXR

Left atrial appendage
- should be concave
- straightening or convexity is seen in patients with rheumatic mitral valve disease and left atrial enlargement
Good inspiration
10th posterior rib
6th anterior rib
Pericardium
- thin line represents the pericardial layers between the epicardial and pericardial fat
- nodularity or >2mm thick is abnormal
Diaphragmatic opening
- aortic hiatus
- esophageal hiatus
- IVC hiatus
- foramen of Morgagni
- foramen of Bochdalek
Aortic hiatus
- aorta
- thoracic duct
- azygos and hemiazygos veins
Esophageal Hiatus
- esophagus
- vagus nerve
Airspace communications
- pores of Kohn - intralveolar channels
- canals of Lambert - bridging terminal bronchioles with alveoli
Bat wing airspace opacities
- pulmonary edema
- pulmonary hemorrhage
Ventilated pts recieving 100% O2 can have completely collapsed lung in a few minutes
- bronchogenic carcinoma/endobronchial lesion
- endotracheal tube malposition
- mucus plugging
- foreign bodies
Pure O2 is absorbed fast by the lungs
Only direct radiographic sign of lobar atelectasis
Dispacement of an interlobar fissure
Indirect signs of lobar atelectasis
- increased density of the atelectic lung
- bronchovascular crowding
- ipsilateral diaphgragm elevation
- ipsilateral tracheal/mediastinal shift
- hilar elevation in upper lobe atelectasis
- hilar depression in lower lobe atelectasis
- compensatory hyperinflation of other lobes
- shifting granuloma - towards the collapsed side
- ipsilateral small hemithorax - close proximity of the ribs - only if chronic atelectasis
Rounded atelectasis
- pleural disease/thickening
- curvilinear bronchovascular bundle/comet tail
- acute angle with the pleura
- enhances following IV contrast
LUL collapse/atelectasis
- best seen in lateral projection
- lateral - major fissure shifts anteriorly and marginating a long narrow band of increased opacity paralleling the anterior chest wall - the collapsed LUL
- frontal - a veil of increased opacity over the left upper hemithorax
- Luftsichel sign - air sickel sign - overinflated superior segment of LLL interposed b/t aortic arch and the collasped LUL
Lobar atelectasis
vs
Lobar pneumonia
- atelectasis - volume loss; no airbronchogram - no air is the cause of the collapse
- consolidation - volume preserved - with pus and exudate; airbronchogram - consolidation orginates from the alveolar space
Mucoid impaction
aka
Bronchocele
- non-obstructive bronchiectasis
- cystic fibrosis
- ABPA
- obstructive bronchiectasis
- endobronchial tumor
- bronchial atresia
Pneumatocele
- thin-walled, gas-containing structures representing distended airspaces distal to a check-valve obstruction of a bronchus or bronchiole
- common - Staph aureus, trauma
- generally resolve in 4 - 6 mons
Focal lucent pulmonary lesions
- cavity - necrosis; communicating with airway
- > 1mm thick
- abscess, neoplasm
- bulla
- < 1mm thick
- > 1cm in diameter
- bleb
- < 1cm in diameter
- in visceral pleural surface, apical
- air cyst
- intraparenchymal gas collection
- > 1mm thick
- pneumatocele
- thin-walled cystic lesion
- staph infection or post-traumatic
- self-resolving
Non-pulmonary causes of
unilateral pulmonary hyperlucency
- pt rotation - increased density over the lung rotated away from the cassette
- Poland syndrome - congenital absence of pectoralis muscle
- mastectomy

Poland Syndrome

True/pulmonary
unilateral hyperlucent lung
- primary vascular abnormality
- pulmonary artery hypoplasia
- lobar resection
- pulmonary arterial obstruction
- shuting of blood away from abnormal lung
- check-valve effect from endobronchial mass/foreign body
- Swyer-James syndome

Swyer-James syndrome
- Adenoviral infection during infancy
- asymmetric bronchiolitis obliterans –> secondary decreased vascularity –> collateral air drift and airtrapping
- Unilateral hyperlucent lung
- Small or normal-sized hemithorax
- Overinflation of contralateral lung
- Diminutive pulmonary hilum
- Decreased peripheral pulmonary arteries
- Mediastinal shift toward the hyperlucent thorax

DDx of unilateral hyperlucent thorax
- technical
- rotation
- chest wall
- mastectomy
- Poland syndrome
- vasculature
- pulmonary artery hypoplasia/stenosis
- pulmonary embolism
- pleural disease
- anterior ptx
- airways
- emphysema
- large bulla
- endobronchial obstruction/FB
- congenital lobar emphysema
- post-infectious bronchiolitis obliterans - Swyer-James syndrome
Presence of calcification within an untreated mediastinal mass virtually excludes what?
Lymphoma

Pneumomediastinum
- most common finding is air outlining the left heart border
- contnous diaphgram sign
Upper limits of interlobar pulmonary artery
- men 17mm
- women 15mm
Classification of thymic tumors
- benign - thymoma
- invasive
- non-invasive (encapsulated)
- malignant - thymic carcinoma
Typical age of thymoma
45-50 years old
What is thymoma associated with
Myasthenia gravis
and other autoimmune dz
- pure red cell aplasia
- graves disease
- sjogren’s syndrome
Low grade
vs
high grade
thymomas
High grade thymomas
- larger
- irregular margins
- heterogenous enhancement
- necrosis
- calcification
- mediastinal nodal metastases
- drop metastasis to the dependent portions of the pleural space*
DDx of thymic masses
- thymoma - invasive vs noninvasive
- thymic carcinoma
- thymic cyst
- thymolipoma
- thymic hyperplasia
- thymic neuroendocrine tumors
- thymic lymphoma
Thymic cyst
- Congenital
- unilocular
- rare
- Acquired
- multilocular
- AIDS, post-radiation/sx, Sjogren syndrome, MG, aplastic anemia
- may mimic cystic degeneration of thymoma
Thymolipoma
- pliable nature
- envelopes the heart and diaphgram
- curable if resected

Thymic neuroendocrine tumor
aka
Thymic carcinoid
- most common histology - thymic carcinoid
- carcinoid -> atypical caricnoid -> small cell
- 40% - cushing syndrome due to ectopic ADTH secretion
- can’t be distinguished from thymoma on CT
Thymic hyperplasia
- most common in children
- rebound effect in response to
- an antecedent stress
- discontinuation of chemoRx
- treatment of hypercortisolism
Thymic lymphoma
- most ocmmonly involved in nodular sclerosing subtype of Hodgkins dz
- presence of other lymphadenopathy suggest the Dx
Hodgkin disease
vs
NHL
- Hodgkin disease
- almost always involves mediastinal/hilar nodes
- contiguous nodal spread
- localized - radiation
- widespread - chemo Rx
- NHL
- only involves one mediastinal/nodal group
- multifocal disorder; unpredictable
- Calcification in untreated lymphoma is extremely uncommon
- Lung parenchymal involvement is due to direct extranodal extension from hilar nodes along the bronchovascular lymphatics
Solid teratoma
vs
cystic teratoma
solid teratoma
- usually malignant
- exclusively in male
What does mediastinal lymphadenopathy look like
for patients with lymphoma?
bilateral LAD
but asymmetric
Isolated posterior mediastinal LAD
Usually only seen in patients with NHL
Sarcoidosis
vs
Lymphoma and metastases
- sarcoidosis - bilateral and symmetric;
- enlarged lymph nodes do NOT coalesce
- lymphoma/mets - bilateral but asymmetric
- intranodal tumor extends through the nodal capsule to form conglomerate enlarged nodal masses
Castleman disease
Angiofollicular lymph node hyperplasia
aka
Castleman disease
- intense enhancement
Foregut cysts
- bronchogenic cyst
- enteric cyst
- complications
- secondary infection
- rapid enlargement due to hemorrhage
- CT appearance
- well-defined, thin-walled mass
- fluid density 0-10 HU
- does not enhance
- > 40 HU due to mucoid material, milk of calcium, blood
Pericardial cyst
- right anterior cardiophrenic angle
- CT - smooth, sharply marginated, low-attenuation mass
- MR or US - subxyphoid approach - simple cyst
Lymph nodes with central calcification
- TB
- Fungal
Lymph nodes with peripheral calcification
aka
eggshell calcification
- sarcoidosis
- silicosis/CWP
Lymph nodes that are hypervascular
intensely enhancing
- carconoid tumor/small cell carcinoma
- Kaposi sarcoma
- metastases
- RCC
- thyroid
- Castlman disease
Lymph nodes that are centrally necrotic
- mycobacteria/TB
- fungus
- metastases
- squamous cell carcinoma
- seminoma
- lymphoma
DDx for anterior mediastinal mass
- thymic masses
- thyroid masses
- germ cell neoplasms
- lymphoma/lymph nodes
- ectopic parathyroid mass
- mesenchymal tumor
- lipoma
- hemangioma
- leiomyoma
- liposarcoma
- angiosarcoma
DDx of middle medistinal mass
- lymph node masses
- malignancy
- infection
- idiopathic - sarcoidosis/Castleman
- foregut or mesothelial cysts
- bronchogenic cyst
- pericardial cyst
- foregut duplication cyst
- tracheal and central bronchial lesions
- diaphragmatic hernias
- Morgagni hernia
- traumatic diaphragmatic hernia
- vascular lesions
- arterial
- venous
DDx of posterior mediastinal mass
- neurogenic tumors
- esophageal lesions
- foregut cysts
- vertebral lesions
- lateral thoracic meningocele
- pancreatic pseudocyst
Neurogenic tumors in the posterior mediastinum
- peripheral (intercostal) nerves
- neurofibroma
- schwannoma
- sympathetic ganglia
- ganglioneuroma - benign
- ganglioneuroblastoma
- neuroblastoma - highly malignant, < 5yo
- paraganglion cells
- chemodectoma
- pheochromocytoma
Multiple lesions in the mediastinum, particularly bilateral apicoposterior mass
neurofibromatosis

Dumbbell neurofibroma
- tumor extension from paravertebral space into the spinal canal via an enlarged intervertebral foramen
- high T2, high post gad
Esophageal pulsion diverticulum
- proximal
- at cervicothoracic junction
- Zenker’s diverticulum
- distal
- juxtadiaphgramatic mss with an air-fluid level
Hiatal hernia
2 types
- sliding hernia - gastric cardia
- paraesophageal hernia - gastric fundas
Lateral thoracic meningocele
is associated with which syndrome?
Neurofibromatosis
Most common posterior mediastinal mass
in patients with neurofibromatosis
lateral thoracic meningocele
Location of tear in
Boerhaave syndrome
- vertical tear
- left posterolateral wall
- esophagogastric junction
Causes of chronic sclerosing/fibrosing mediastinitis
- histoplasmosis
- TB
- radiation
- drugs - methysergide
Most commonly affect structure in
chronic sclerosing/fibrosing mediastinitis
- SVC
Most common CXR finding of
chronic sclerosing/fibrosing mediastinitis
asymmetric, lobulated widening
of the upper mediastinum
Most common cause of pneumomediastinum
air from the lungs
- sudden rise in intrathoracic and intraalveolar pressure
- air dissecting along the bronchovascular interstitium
- dissects centrally - pneumomediastinum
- Macklin effect
- dissects peripherally - pneumothorax
Causes of pneumomediastinum
- alveolar rupture
- tracheal/bronchial
- esophageal
- fistula formation
- recent sx - sternotomy, thoracotomy
- pneumoperitoneum
- along the internal mammary vascular sheaths
- pneumoretroperitoneum
- along the aortic hiatus
- subc emphysema in the neck, stab wound, laryngeal fracture
- dissect along the retrophayngeal space, prevertebral space, or along the great vessel sheaths

pneumomediastinum
Ludwig angina
- infection of the floor of the mouth extending inferiorly to involve the mediastinum
- retrosternal chest pain
Hilar mass is often obscured by
adjacent lung collapse
obstructive pneumonits
Posterior mediastinal involvement in
extrathoracic malignancy
- RCC, testicular cancer
- retroperitoneal nodes –> thoracic duct –> posterior mediastinal nodes
- if valve incompetency –> anterior, hilar lymph nodes
Primary vs Secondary
pulmonary lymphoma
- Primary - parenchymal and pleural involvement
- Secondary - intrathoracic lymph node involvement
Post-primary TB does NOT have?
Hilar or mediastinal lymphadenopathy
Classic findings of pneumonic plague
Hyperdense mediastinal and hilar LAD on unenhanced CT due ot intronodal hemorrhage
What viral infections give medistinal and hilar LAD
Mononucleosis
Measles
Most common cause of BILATERAL hilar adenopathy?
small cell carcinoma
melanoma
lymphoma (Hodgkin dz)
DDx for small hilum (hila)
- Unilateral
- absence or hypoplasia of PA
- hypoplastic or hypogenetic lung - Scimitar syndrome
- Swyer-James syndrome
- lobar atelectasis
- lobar resection
- compression or invasion of PA
- Bilateral
- emphyema/COPD
- obstruction of the main PA flow
- sclerosing mediastinitis
- valvular pulmonary stenosis
- embstein anomaly
Pulmonary edema
interstitial edema
–>
alveolar (airspace) edema
–>
impaired oxygen and CO2 exchange
Kerley lines
- Kerley A - central connective tissue septal thickening
- Kerley B - peripheral interlobular septal thickening
- Kerley C - network of thickened interlobular septa
Causes of unilateral pulmonary edema
- positional - pt is decubitus; may shift with pt positioning
- protective effect - one pulmonary arterial flow is diminished by pulmonary embolus or extrinsic compression
- re-expansion pulmonary edema from ipsilateral pleurocentesis
Cause of alveolar pulmonary edema localized to RUL
Severe mitral valve regurgitation
Causes of pulmonary edema
- hydrostatic pulmonary edema
- increased capillary permeability edema (ARDS)
- neurogenic pulmonary edema
- high-altitude pulmonary edema
- re-expansion pulmonary edema
- acute upper airway obstruction edema
- amniotic fluid embolism
- fat embolism
Neurogenic pulmonary edema
- following head trauma, seizure, increased ICP
- massive sympathetic discharge from the brain
*
High-altitude pulmonary edema
- response to hypoxia
- scattered areas of pulmonary arterial spasm - pulmonary arterial hypertension
- over flow of lood at thigh pressure to uninvolved areas
- daage of capillary endothelium and increased permeability edema
- PATCHY in distribution
Re-expansion pulmonary edema
- negative intrapleural pressure
- free-radical injury upon reperfusion after prolonged collapse and ischemia
Causes of pulmonary hemorrhage
- spontaneous
- thrombocytopenia
- hemophilia
- anticoagulant therapy
- trauma
- pulmonary contusion
- embolic
- pulmonary embolism/infarction
- fat embolism
- vasculitis
- autoimmune
- Goodpasture syndrome
- Wegener’s granulomatosis
- idiopathic pulmonary hemorrhage
- SLE/RA
- infectious
- gram-ve bacteria
- influenza
- aspergillosis
- mucormycosis
- autoimmune
- drugs
- penicillamine*
Goodpasture syndrome
- cytotoxic Ab directed at the renal glomerular basement membranes and cross reacts with alveolar basement membrane
- young adult male
- recurrent hemorrhage leads to pulmonary fibrosis
- Dx - immunofluorescent studies of renal or lung tissue - smooth wavy line of fluorescent staining along the basement membrane
Goodpasture syndrome
vs
Idiopathic pulmonary hemorrhage
- Goodpasture syndrome
- young male
- anti-GBM Ab
- renal and pulmonary involvment
- Idiopathic pulmonary hemorrhage
- children, equal sex distribution
- no anti-GMB Ab
- no renal involvement
Pulmonary hemorrhage can lead to
Elevated CO diffusion capacity
Most common finding on CXR
in patients with PE
- Majority - abnormal
- most common finding - atelectasis - Type 2 pneumocytes ischemic -> surfactant deficiency
- Westermark sign
- Hampton hump
- 40% - normal
- Utility of performing CXR
- rule out pneumonia, PTX
- aid VQ scan
How to distinguish regular pulmonary arterial hypertension from the presence of a left-to-right shunt?
- PAH - pruning - enlarged main and hilar pulmonary arteries that taper rapidly toward the lung periphery
- Left-to-right shunt - pulm vascular resitance drops initially - enlargement of both central and periphal pulmonary arteries producing “shunt vascularity”
- later on, medial hyperplasia and intimal fibrosis –> regular PAH pruning
Shunt vascualrity
Initially if there is a left to right shunt, pulm vascular resistance drops to accomodate - shunt vascularity
later, as medial hyperplasia and intimal fibrosis -> increased pulm vascular resistance –> pruning
Pulmonary capillary hemangiomatosis
PCH
proliferation of capillaries throughout the pulmonary interstitium –> venular obstruction > increased pressure to pulmonary arterial side with medial hypertrophy and obliteration of vesel lumina
CXR - pulmonary artery hypertension but NO pulmonary venous hypertension
What kind of margin is strongly suggestive of malignancy
- notched/lobulated margin
- spiculated margin
Benign calcifications of
pulmonary nodule
- complete calcification
- central calcification - bull’s eye - histo/TB
- concentric/laminated calcification - granuloma
- periphralcalcification
- popcorn calcification - hamartoma (calcified cartilaginous componenet)
Pulmonary nodule that contains fat?
Dx of hamartoma
Solitary pulmonary nodules
- neoplasm
- bronchogenic carcinoma
- hamartoma, bronchial adenoma, granular cell myoblastoma, mesenchymal neoplasm
- lymphoma
- carcinoid
- solitary metastasis
- infection
- septic embolus
- round pneumonia
- lung abscess
- infectious granuloma
- parasitic - echinococcal cyst
- inflammation
- Wegener’s granulomatosis
- necrobiotic nodule (rheumatoid lung)
- vascular
- AVM
- PA aneurysm
- hematoma
- airways
- bronchogenic cyst
- foregut duplication cyst
- sequestration
- mucocele
- miscellaneous
- round atelectasis
- amyloidoma
Typical findings of a pulmonary hamartoma
- < 2.5 cm
- smooth or lobulated borders
- contain focal fat
- popcorn calcification - multiple clumps of calcifium dispersed throughout the lesion
- rule - hamartomas that contain calcium also contain fat!
Bronchogenic carcinoma types
- adenocarcinoma - most common
- BAC - lepidic growth*
- grow along pre-existing bronchiolar and alveolar without invasion or distortion of these structures
- solitary pulmonary nodule
- ground glass opacity
- squamous cell carcinoma
- hilar mass with obstructive pneumonitis
- small cell carcinoma
- large cell
- large peripheral mass
In order for a mass (squamous cell carcinoma)
to cavitate, what mus thapen?
Communication of the mass with the bronchial lumen
Bronchial neuroendocrine tumors
spectrum
- Kulchitsky cells (KCC)
- KCC-1 - typical carcinoid tumor
- KCC-2 - atypical carcinoid tumor
- KCC-3 - small cell carcinoma (most malignant)
Where do bronchogenic carcinomas arise from?
- small cell carcinoma and squamous cell carcinoma
- central bronchal epitheium
- adenocarcinoma and large cell carcinoma
- bronchial and alveolar epithelium
Manifestation of an endobronchial obstructing lesion
- lobar atelectasis, OR
- post-obstructive pneumonitis
- preserved volume or even increased volume
- bulging conexity/interlobar fissure
- “drowned lung”
- chronic inflammatory infiltrate - alveolar filling with lipid-laden macrophages - endogeneous lipoid pneumonia
- obstructed lung often obscures the underlying mass
- collapsed lung - enhancing
- mass - hypodense!
- distal to the endonbronchial obstructing lesion - mucus plugging - mucus bronchogram
How to differentiate a cavitating malignant lesion
from
a cavitating inflammatory lesion
Cavitating neoplasms tend to be thicker and more nodular than cavitating inflammatory lesions
What findings are suggestive of a BAC
air bronchograms
bubbly lucencies
mixed solid/GGO
CT angiogram sign
- Diffuse form of BAC
- low-density airspace opacification due to mucoid material produced by the malignant cells
- surrounding enhancement pulmonary vessels
- Other DDx for CT angiogram sign
- BAC
- lymphoma
- lipoid pneumonia
Isolated adrenal masses in patients with NSCLC
Twice likely to be benign adrenal adenomas than metastases
- CT
- unenhanced CT < 10 HU
- enhanced delayed CT > 60% washout
- MR
- chemical shift
- PET
- high sensitivity - if negative, r/o adrenal mets
- but low specificity - if positive, may still be adenoma
Pulmonary carcinoid tumor
- right upper and middle lobes
- hemoptysis due to hypervascularity
- main have
- atelectasis or post-obstructive pneumonitis
- hyperlucent lung due to collateral air flow and reflex hypoxic vasocontriction
- iceberg tumor - small intraluminal and large extraluminal soft tissue component
- marked contrast enhancement
- may have punctate calcification
Morphology of pulmonary metastsis
vs
bronchogenic carcinoma
- pulmonary metastasis - smooth in contour
- bronchogenic carcinoma - lobulated and spiculated
The likelihood that a solitary pulmonary nodule
SPN
represents a mets or bronchogenic carcinoma
- if synchronous extrathoracic malignancy - 50%
- if prior malignancy - almost always a primary bronchogenic carcinoma
How to confirm the Dx of lymphangitic carcinomatosis?
transbronchial bx
Nodular lymphoid hyperplasia
Not quite lymphoma yet
non-neoplastic reaction proliferation of lymphocytes in the lung
Lymphocytic interstitial pneumonitis
- infiltration of the pulmonary interstitium by lymphocytes
- associated with
- Sjogren syndrome
- hypogammaglobulinemia
- Castleman syndrome
- AIDS
- lower lobe predominance
- diffuse GGO with poorly defined centrilobular nodules, and thin walled cysts

Lymphocytic interstitial pneumonitis
LIP
Posttranslant lymphoproliferative disorder
PTLD
- solitary or multiple sharply marginated nodules or masses
- Rx: reduction in immunosuppression
Pulmonary kaposi sarcoma
- AIDS patients
- pulmonary involvement always follow skin, oropharyngeal, and/or visceral involvement
- small to medium, poorly marginated nodular and coarse linear opacities
- extending from hilum to mid and lowe rlung
- slow progression, relatively asymptomatic
How to differentite
Kaposi sarcoma
vs
pneumonia
vs
lymphoma
- pneumonia - both gallium and thallium avid
- lymphoma - gallium avid only
- KS - thallium avid only

Pulmonary blastoma
- young adults
- extremely large at presentation
3 potential routes of pulmonary infection
- tracheobronchial tree
- lobar pneumonia
- bronchopneumonia
- interstitial pneumonia
- pulmonary vasculature
- direct extension from the mediastinum, chest wall, and upper abdomen
Lobar pneumonia
- pneumococcal infection
- exudate begins within distal airspaces
- spread through pore of Kohn and canals of Lambert
- airways are usually spared
- air bronchograms
- volume loss unusual
Bronchopneumonia
- most common pattern of pneumonia
- staphylococcal pneumonia
- centered in and around lobular bronchi
- multifocal opacities that are roughly lobular in configuration - patchwork quilt
- exudate within the bronchi –> no air bronchograms
- when affected areas coalesce, may look like lobar pneumonia

Bronchopneumonia
Interstitial pneumonia
- viral or mycoplasma infection
- inflammatory thickening of bronchial and bronchiolar walls and the pulmonary interstitium –> CXR airway thickening and reticulonodular opacities
- alveolar spaces remain aerated –> no air bronchograms
- semental and subsegmental atelecatsis
Bacillus anthracis infection
- hemorrhagic lymphadenitis and mediastinitis - hyperdense lymph nodes
- hemorrhagic pleurla effusions - hyperdense
- peribronchial opacities

Anthrax
Legionella pneumophila
- gram negative bacteria
- air conditioning and humidifier system
- may present as ROUND PNEUMONIA
- may progress to lobar or multilobar pneumonia despite the intiation of abx rx
- radiographic resolution of pneumonia is often prolonged and lag behind symptomatic improvemen
Actinomycosis
- normal anaerobic organism in the human oropharynx
- causes disease when gaining access to devitalized or infected tissue
- dental - extension from mandibular osteomyelitis
- thoraic actinomycosis - spread contiguous tissue - pleura, chest wall, ribs
Mycoplasma
- most common atypical pneumonia
- CXR - fine reticular pattern –> segmental airspace –> lobar consolidatoin
- CT - tree-in-bud appearance - bronchiolitis
Primary TB
- most often affect children
- incidence in adults increases b/c AIDS
- most pts with primary TB are asymptomatic
- in some patients
- Ranke complex - calcified parenchymal focus (Ghon lesion) + nodal calcification
- parenchymal consolidation
- unilateral pleural effusion
- tuberculous empyema - may break thr the parietal pleura to form an extrapleural collection - empyema necessitatis
- hematogenous spread of infection during primary TB infection
- lung apices
- renal medulla
- bone marrow
Post-primary TB
- cough & constitutional sx
- vs. 1 TB asymtpomatic
- apical and posterior segments of upper lobes; superior segments of lower lobes
- cavitation
- transbronchial spread
- Rasmussen aneurysm - cavitary focus erodes into a branch of the pulmonary artery –> hemoptysis
- granulomatous response - parenchymal healing
- fibrosis
- bronchiectasis
- volume loss - cicatrizing atelectasis
- PAH
- mycetoma in TB cavity
- broncholith - erosion of calcified peribronchial lymph node into the bronchus
- bronchostenosis
Milliary TB
- can affect both primary or post-primary TB
- 2-3 mm nodules - randome distribution
- high mortality
Atypical mycobacterial infection
- most common - mycobacterium avium intracellulare (MAI)
- typical presentation
- like post-primary TB
- atypical presentation
- middle or elderly women
- middle lobe and lingula
- peribronchial nodules
- tree-in-bud
Viral pneumonia
- bronchopneumonia or interstitial pneumonia
- usually complete resolution
- but may have
- bronchiectasis
- bronchiolitis obliterans - Swyer James Syndrome
- interstitial fibrosis

Healed varicella pneumonia
Varicella-zoster pneumonia
- severe pneumonia in adults
- diffuse bilateral ill-defined nodular opacities 5-10 mm
- usually resolve completely
- in some patients my involute and calcified - innumerable small 2-3mm calcified nodules
Spectrum of aspergillus caused pulmonary disease
aspergilloma
semi-invasive aspergillosis
invasive aspergillosis
ABPA

Waterlily sign
Hydatid disease - echinococcal cyst
Rim-enhancing lymph nodes with central necrosis on CT are characteristic finding for what?
TB in an AIDS patient

Halo sign
- angioinvasive aspergillosis
- surrounding edema and hemorrhage
What is the most common cause of fungal infection in the AIDS patients?
Cryptococcosis
- AIDS-defining opportunistic infection
- can affect any immunocompromised hosts
- RARELY affect immunocompetent pts
- 2 subtypes
- cryptococcus neoformans
- cryptococcus gattii
PJP
PCP
- fine reticular or gg pattern
- pregressive dz - confluent symmetric a/s opacification
- thin0walled cysts
- pleural effusion and LAD UNCOMMON
Pulmnoary complications post-BMT
- neutropenic phase (0-1mo)
- pulmonary edema
- alveolar hemorrhage
- fungal infection
- drug reaction
- early phase (1-3mo)
- fungal infection
- drug reaction
- CMV infection
- upper resp virus infection
- idiopathic pneumonia
- acute GVHD
- late phase (>3mo)
- bronchiolitis obliterans
- BOOP
- chronic GVHD
- upper resp virus infection
- idiopathic pneumonia

Subpleural band
- parallel the chest wall
- asbestosis >> IPF

Parenchymal band
- asbestosis
- sarcoidosis
- UIP
Honeycombing
- lined by bronchiolar epithelium - bronchiectasis
- IPF
- chronic HSP
- occasionally - sarcoidosis
Gound glass opacity
- pulmonary alveolar proteinosis
- pulmonary hemorrhage
- pulmonary edema
- infection - PCP, CMV
- interstitial lung dz
- UIP
- NSIP
- DIP
- HSP
- RB-ILD
Interstitial lung dz presents as
conglomerate masses
- sarcoidosis
- silicosis/CWP - PMF
- post-radiation fibrosis
- IVDU - talcosis, starch
Manifestations of RA lung diseases
- serositis
- pericardial effusion
- pleural effusion
- interstitial pneumonitis
- UIP
- necrobiotic nodules
- peripheral cavitating nodules, rheumatoid nodules
- Caplan syndrome
- bronchiolitis obliterans
- COP
- pulmonary arteritis
- pulmonary arterial hypertension, right heart enlargement
- pulm hemorrhage
- chest wall
- tapered distal clavicles
- GH joint arthropathy
- rotator tendon atrophy - high riding humeral head
- superior rib notching/erosion