Respiratory Flashcards
Helpful videos
https://www.youtube.com/watch?v=ikwN7CLTBlY
COPD https://www.youtube.com/watch?v=qn0KHo8Y6B4
ASTHMA
https://www.youtube.com/watch?v=NbfevYRM2vQ
RSV AND BRONCHIOLITIS
https://www.youtube.com/watch?v=Y62TCz3reZc
COR PULMONALE
https://www.youtube.com/watch?v=UQGRcg35Dmk
PLEURAL EFFUSION
https://www.youtube.com/watch?v=gASiQ2I_4KY
LUNG CANCERS
https://www.youtube.com/watch?v=5DmUfK5gz5g
TB
https://www.youtube.com/watch?v=6P6zBHpWiGA
PNEUMONIA
https://www.youtube.com/watch?v=IAQp2Zuqevc
CF
https://www.youtube.com/watch?v=CqFsAwCFvCM
EMPHYSEMA
https://www.youtube.com/watch?v=TEuSV_7gWA8
CHRONIC BRONCHITIS
https://www.youtube.com/watch?v=Y29bTzKK_P8
COVID 19
https://www.youtube.com/watch?v=DqnrqV6ogGw
Lateral CXR
Taken in left lateral position.
Right ribs magnified and posterior.
Black hole on lateral is LUL bronchus, in front of this is RPA and on top is LPA.
On frontal, left hilum always 1cm higher than right.
Retrotracheal triangle (Raiders triangle) on lateral. Opacity in here is aberrant right subclavian artery
Prosthetic cardiac valves
Pulmonic valve most superior
Tricuspid valve most anterior
Aortic in front of mitral on lateral
Azygos lobe fissure
Variant anatomy. Happens when azygos vein is displaced laterally during development. Resuts in deep fissure is RUL. Not an accessory lobe but variant of RUL. 4 layers of pleura
Segmental lung
RUL
apical, anterior, posterior
RML
Medial, lateral
RLL
Superior, posterior, lateral, anterobasal, medial basal
LUL
anterio, apical posterior
LUL-L
superior, inferior
LLL
Superior, posterior, lateral, antero-medial basal
Variant airway anatomy
PIG/TRACHEAL BRONCHUS
Comes off right trchea prior to bifurctaion. Means nothing clinically but can get air trapping or recurrent infections from impaired ventilation. Recurrent RUL penumonia in kid.
CARDIAC BRONCHUS
Bronchus off bronchus intermedius, opposite to origin of RUL bronchus. Usually blind ending and is supernumary. Means nothing clinically but can get recurrent infection
Mediastinal anatomy
SUPERIOR
Inf border is oblique plane from sternomanubrial junction
ANTERIOR
Posterior border is pericardium
MIDDLE
Heart, pericardium and bifurcation of trachea are all included. Posterior to trachea and anterior to vertebral bodies
POSTERIOR
Back of heart to spine. Contains esophagus, thoracic duct and descending aorta
Mediastinal variant anatomy
PULMONARY VEINS
Pulmonary vein anatomy is variable. Typically 2 upper and 2 lower on each side. Main variant is separate vein draining RML
PROX INTERRUPTION OF PULMONARY ARTERY
Congenital absence of right of left PA with more distal pulmonary vasculature present. Could be shown as volume loss in one hemithorax then contrast CT with only one PA. Seen on opposite side to aortic arch. Associated with PDA. Interrupted left PA is seen with TOF and truncus. Recurrent infections due to lack of blood supply
Atelectasis (incomplete lung expansion)
OBSTRUCTIVE/ABSORPTIVE
Complete obstruction of an airway. No air entering, current air eventually absorbed. Obstructing neoplasm, mucous plugging, foreign body
COMPRESSIVE
Direct mass effect on lung. Usually from pleural effusion or next to mass/hiatal hernia/bleb/tortuous aorta etc
FIBROTIC
Fromscarring/fibrosis which fails to allow lung to collapse completely. Usually TB, radiation or other infections. Anything with fibrosis.
ADHESIVE
Loss of surface tension/inadequate pleural adherence of alveolar walls - surfactant deficiency. Alveoli become unstable and collapse. Causes RDS (premmies), ARDS, PE
Atelectasis primary and secondary signs
SHADOW
Shadow made by opacified collapsed lung. Direct sign, most obvious.
SILHOUETTE
Loss of interface between opacity and adjacent normal structures. Usefull in localization
SHIFT
Movement of structrues as they are pulled toward site of volume loss. Space occupying things push away, atelectasis pulls toward
Lobar patterns collapse
RML
Increased density right heart border with loss of that border. Lateral shows anterior density over heart
- RML/Lady Windermere syndrome is chronic collapse with MAI syndrome in elderly women too proper to cough. Additional nodules and bronchiectasis. Lungula often involved.
RLL
Increased density right heart border similar to RML but you still have right heart border visible. Mediastinal vessels can be pulled to right creating triangle of opacity rightward of trachea (superior triangle sign).
RLL and RML
Sneaky. Loss of visualization of right hemidiaphragm and right heart border. Reverse S sign of Golden is RUL collapse with obstructing mass
RUL
Horizontal fissure bows upward. Hilum may elevate.
Lobar patterns collapse continued
LUL
More subtle with increased density medially. No wel defined borders. Non visualization of aortic knob. May get peaking of diaphragm from upward traction.
Air Sickle sign of hyperinflated apical segment of LLL pinned between medial edge of collapsed segment and aortic arch
LLL
Opacity hidden behind heart. Lateral more obvious with triangle opacity. Flat waist sign is flattened appearance of the contours of hilum and heart border
CXR localization
CERVICOTHORACIC SIGN
Takes advantage of posterior junction line. Things above the clavicles are in posterior mediastinum
HILUM OVERLAY SIGN
Mass at level of hilum arising from hilum with obliterate silhouette of pulmonary vessels. If you can see vessels through mass then it is either anterior or posterior.
PULMONARY vs MEDIASTINAL ORIGIN
Pulmonary will have air bronchograms and make an acute angle with lung. Mediastinal will make an obtuse angle with lung
Bacterial infection
STREP PNEUMONIAE
Lobar consolidation.Favours lower lobes. Most common in AIDS
STAPH AUREUS
Bronchopneumonia, patchy opacity. Bilateral, can make abscess, endocarditis.
KLEBSIELLA
Bulging fissure, exuberant inflammation. Pleural effusions, empyema, cavitates. Currant jelly sputum. Alcoholics, nursing home patients.
HAEMOPHILUS INFLUENZA
Bronchitis, bilat lower lobes. COPD, asplenic patients.
PSEUDOMONAS
Patchy opacities with abscess. ICUers on ventilators. Cavitates in immunosuppressed.
ASPIRATION
Anaerobes, can cavitate. Posterior lower lobes when supine. Favours right side. Empyema, can get bronchopleural fistula.
ACTINOMYSES
Peripheral lower lobes. Can be aggressiveand invade chest wall. Dental procedure gone bad, mandible osteo, aspiration.
MYCOPLASMA
Fine reticular pattern on CXR, patchy airspace opacity. Tree in bud.
Post bone marrow transplant
Pulmonary infections in nearly 50% people after bone marrow transplant. Most common cause of death in this group.
EARLY NEUTROPENIC
0-30 days. Pulmonary oedema, haemorrhage, drug induced lung injury. Fungal pneumonia (invasive aspergillosis)
EARLY
30-90 days. PCP, CMV.
LATE
>90 days. Bronchiolotis obliterans, cryptogenic organizing pneumonia
AIDS related pulmonary infection
PCP
Most classic AIDS infection. Ground glass opacities bilaterally in perihilar regions with sparing of periphery. Thin walled cysts can occur.
Most common airspace opacity - Strep Pneumonia
Ground glass - PCP
Flame shaped perihilar opacity - Kaposi Sarcoma
Persistent opacity - Lymphoma
Lung cysts - LIP
Lung cysts and ground glass and PTX - PCP
Hypervascular LNs - Castleman or Kaposi
AIDS infection by CD4
> 200 bacterial infections, TB
<200 PCP, atypical mycobacterial
<100 CMV, disseminated fungal, mycobacterial
TB
PRIMARY
Inhaled bug, causes necrosis. Body attacks and causes granuloma (Ghon focus). End up with bulky nodal expansion which can calcify and form Ranke complex. Bulky nodes cause compression leading to atelectasis. If node ruptures get endobronchial or haematogenous spread. Haematogenous spread manifests asmiliary patten. Cavitation not common in primary.
PRIMARY PROGRESSIVE
Local progression with development of cavitation (at initial site of infection and/or haematogenous spread. Primary progression uncommon. HIV a risk factor along with anything that akes you immunosuppressed such as transplant patients, steroids. Similar to post primary disease.
LATENT
Positive PPD with a negative CXR and no symptoms. If ou have TB vaccine, considered latent.
POST PRIMARY/REACTIVATION
5% of time this happens. Endogenous reactivation of latent infection. Classic location apical and posterior upper lobe and superior lower lobe (more oxygen, less lymphatics). Post primary infection tend to have progression. Development of cavities. Rasmussed aneurysm is in close by vessel in setting of TB cavitation
TB facts
Pleural invovlement can happen at any time after intitial infection. Pleural fluid usually negative need to biopsy pleura.
Primary = no cavity
Post primary/primary progressive = cavity
Ghon lesion = calcified TB granuloma and sequale of primary TB
Ranke complex = calcified TB granuloma and calcified hilar LNs, healed primary TB
Bulky hilar and paratracheal LNs = in kids
Reactivation TB = posterior/apical upper lobes, superior lower lobes
Miliary spread = haematogenous dissemination
Reactive TB pattern = cavitation seen in HIV patient CD4<200
Primary progressive pattern = adenopathy, consolidation, miliary spread
Non TB mycobacteria
CAVITATORY(CLASSIC)
Usually MAC. Favours old white man with COPD. Looks like reactivatin TB. Upper lobe cavitatory lesion with adjacent nodules
BRONCHIECTATIC (NON CLASSIC)
Lady Windermere. Favours old white lady. Asymptomatic, dont cough. Tree in bud with cylindrical bronchiectasis in RML and lingula
HIV PATIENTS
CD4<100. GI infection disseminated in blood. Big spleen and liver. Can look like anything. Mediastinal LNs common.
HYPERSENSITIVITY PNEUMONITIS
Hot tub lung. Aerosolized bugs. Ill defined ground glass centrilobular nodules.
Aspergillus
NORMAL IMMUNE Fungus ball (aspergilloma) in pre-existing cavity. Didnt make the cavity, found it. Cavity can be from any cause.
SUPPRESSED IMMUNE
Invasive aspergillus. AIDS or transplant patients.
‘halo’ sign is cosolidation with ground glass halo - halo is invasive component.
‘air crescent sign’ is thin cresecent of air within consolidative mass, represents healing as necrotic lung separates from parenchyma.
HYPERIMMUNE
ABPA allergic bronchopulmonary aspergillosis. Long standing asthma or CF. Central sacuular bronchiectasis with mucoid impaction ‘finger in glove’. Need elevated serum immunoglobulin E or positive skin hypersensitive test against fungus. Total IgE >1000
Mucormycosis
Aggressive fungal infection usually in impared patients (AIDS, steroids, diabetics). Invasion of mediasitnum, pleura and chest wall
CMV
Two scenarios:
- Reactivation of latent virus after prolonged suppression (post bone marrow transplant)
- Infusing of CMV positive marrow or in other blood products.
Timing for bone marrow patients is 30-90 days. Get multiple nodules, ground glass or consolidative.
Viral trivia
MEASLES
Multifocal GGO with small nodular opacities. Pneumonia befor or after skin lesions. Complications higher in preg and immunocompromised.
INFLUENZA
Coalescent lower lobe opacity. Pleural effusion rare.
SARS-CoV1
Lower lobe predominant GGO
VARICELLA
Multiple peripheral nodular opacities. Small round calcific lung nodules in healed version. Chickenpox in kids. Pneumonia in immunicompromised adults.
EBSTEIN BARR
LN enlargement. Uncommonly affects lung. Big spleen.
Covid 19/SARS CoV 2
SARS CoV 2 is the virus,COVID 19 refers to 2019 pandemic. Increased risk of DVT, PE, stroke, MI or arterial or venous clots. Increased risk of barotrauma from mechanical ventilation.
CXR
Bilateral peripheral lower zone multifocal opacities. Pleural effusion uncommon.
CT ACUTE
Bilateral peripheral GGO, bronchovascular thickening. Crazy paving and reverse halo.
CT LATE >14 DAYS
Fibrous stripes in regions of previous disease
Septic emboli
Multiple causes. Infected tricuspid valves, infection in body, infected catheters, teeth etc.
Lower lobe predominant, peripheral nodular densities and wedge shaped densities (can infarct). Can cavitate. Feeding vessel sign is nodule with big vessel going into it. Empyema and PTX complications.
LEMIERRE SYNDROME
Jugular vein thrombosis with septic emboli usually after oropharyngeal infection or ENT surgery.
Most common bacteria is fusobacterium necrophorum
CAVITY is acronym Cancer Auto immune (Wegeners/Rheumatoid/Caplan) Vascular septic or bland emboli Infection TB Trauma pneumatocoele Y young or congenital CCAM sequestration
Lung cancer risk factors
RISK FACTORS
>30yo, exposure to harmful chemicals, lung fibrosis, COPD and family history. Fibrosis increases risk 10x. Smoking remains main risk factor
Solitary pulmonary nodule SPN
Round/oval lesion <3cm. Surrounded by lung parenchyma with no adenopathy or effusion. Can have numerous “solitary’ nodules on lungs.
4 benign calc patterns
Solid/diffuse, laminated, central, popcorn.
Eccentric calc is most suspicious calc. Part solid lesion with GG component is most suspicious morphology
BENIGN
Presence of fat, rapid doubling time <1 month, slow doubling time stable at 2 years
MALIGNANT
SPiculate margins, air bronchogram through nodule (think adenocarcinoma in situ), partially solid with GG component
PET for >1cm
Solid nodule HOT cancer, COLD benign
GG nodules HOT infection, COLD cancer
SPN/cancer trivia
Lung cancer more common right lung.
70% cancers in upper lobe, except in pulmonary fibrosis where lower is more common.
SPN in setting of H&N cancer is more likely to be primary bronchogenic carcinoma than metastasis (similar risk factors)
Lung cancer rare <40 (unless AIDS)
Air bronchograms 5x more common in malignant SPN
Air bronchograms 50% BACs
Lung cancer subtypes
SMALL CELL
Central. Most common lung ca to cause SVC obstruction and paraneoplastic syndromes. Bad prognosis. Paraneoplastic syndromes associated with SIADH and ACTH. Lamberteon Eaton syndrome is paraneoplastic syndrome with proximal muscle weakness.
NON SMALL CELL - SQUAMOUS
Central. Strong association with smoking. Cavitation classic. No TTF1 expression. Paraneoplastic syndromes can be associated with ectopic parthyroid hormone.
NON SMALL CELL - LARGE CELL
Peripheral. Least common. Usually large >4cm.. ad prognosis
NON SMALL CELL - ADENOCARCINOMA
Peripheral. Most common 35%. Favours upper lobe. ost likely to present as SPN. Most common in non smoker. Association with pulmonary fibrosis and smoking. May only present with lymphadenopathy.
Central tumours haemoptysis, peripheral tumours pleuritic chest pain.
Bronchoalveolar carcinoma (adenocarcinoma in situ spectrum)
PREINVASIVE LESION SPECTRUM Atyical adenomatous hyperplasia of lung (AAH) Adenocarcinoma in situ Minimally invasive adenocarcinoma (MIA) Invasive mucinous adenocarcinoma
The larger the solid component within a part solid nodule is the more likely it is to be malignant.
Superior sulcus/Pancoast tumour
Typically non small cell cancer. SHould be apical tumour with at least shoulder pain, sometimes C8-T2 radiculopathy and Horner syndrome.
MRI is tool of choice for staging.
Contraindication to surgical resection is invasion of vertebral body, invasion of spinal canal, involvement in upper brachial plexus, diaphragm paralysis or distal mets
Lung cancer staging
Use TNM staging
TUMOUR
T1 = <3cm
T2 = 3-5cm, invading pleura, invading main bronchus, obstruction extending to hilum
T3 = 5-7cm, invades chest wall, invades pericardium, invades phrenic nerve, satellite nodule in same lung lobe
T4 = >7cm, invades mediastinal fat or great vessels, invades diaphragm, involves carina, satellite nodules in another lobe
NODES
N1 = ipsilateral within lung up to hilar nodes
N2 - ipsilateral mediastinal or subcarinal nodes
N3 = contralateral mediastinal or contralateral hilum or scalene/supraclavicular nodes
Lung cancer staging continued
CT unreliable for staging. PETCT far superior regardless of size and threshold. Important boundary to identify is distinction between level 1 and 2 nodes as this may change resectability
Level 1 nodes are above line from lower clavicles to upper manubrium (thoracic inlet).
CONTRAINDICATIONS TO RESECTION Growth through a fissure Invasion of pulmonary vasculature Invasion of main bronchus Invasion of both upper and lower lobe bronchi N2 if tumour is >5cm and N3 disease. Multilobar disease Malignant pleural effusion
Distinction between 3a and 3b is critical as 3b is unresectable.
Lung cancer treatment
WEDGE RESECTION VS LOBECTOMY
If 1a or 1b is peripheral and <2cm can consider wedge resection. Advantage over lobectomy is preserving pulmonary reserve. If >3cm, lobectomy normally done.
BRONCHOPLEURAL FISTULA
Uncommon complication of pneumonectomy. Normally space fills with fluid, if this preogressively fills with air thats a fistula.
COMPENSATORY EMPHYSEMA
Post pneumonectomy syndrome. Vocab used to describe hyperexpansion of one lung to compensate for other.
RADIATION CHANGE
Appearance of radiation pneumonitis is variable and based on volume of lung involved/how much radiation given and if chemo also used. Ribs within field are susceptible to degradation and fracture. In RFA and MWA normal to see bubbles in lesion immediately after.
RECURRENT DISEASE
Recurrence rates relatively high. Look at periphery of radiation bed, regional nodes and bronchial stump. Radiaiton morphology is not round so if you see something round consider recurrence. Other suspicious findings are enhancing solid tissue along resection line which is enlarging. New enlarged mediastinal LNs, new pleural effusion
Mimics/other cancers
PULMONARY HAMARTOMA
Macroscopic fat and popcorn calcification. Most common benign lung mass. Usually incidental. Can be hot on PET but still benign.
KAPOSI SARCOMA
Most common lung tumour in AIDS CD4 <200 (lymphome is 2nd). Tracheobronchial mucosa and perihilar lung are favoured. Buzzword is flame shaped. Most common lung tumour in AIDS, most common hepatic neoplasm in AIDS. Slow growth, asymptomatic patient despite bad look. Blood pleural effusion common 50%. Thallium positive, gallium negative
Metastases
DIRECT INVASION
Most common is esophageal carcinoma, lymphoma or germ cell tumour. Seen in cancer of mediastinum, pleura or chest wall.
HAEMATOGENOUS
Most common manifestation is pulmonary nodules in random distribution favouring lower lobes. Canonball mets classic from RCC or chorio. Nodules smoother than primary. Main culprits breast, kidney, thyroid, colon, H&N squam. Feeding vessel sign is prominent pulmonary vessel heading into nodule but can be seen in septic emboli too.
LYMPHANGITIC CARCINOMATOSIS
Most common casue of unilateral LC is actually BAC invading lymphatics. Most common extrathoracic is breast, stomach, panc and prostate. Nodular thickening of interlobular septa and subpleural intersititium. Does not distort pulmonary lobule
Pulmonary lymphoma
PRIMARY
Rare, usually NHL. 80% low grade MALT
SECONDARY
Pulmonary involvement of systemic lymphoma. Much more common than primary. NHL more common overall but HL more common to involve lungs. HL get nodes and parenchyma, NHL parenchyma only.
PTLD
After solid organ or stem cell transplant. Usually within a year. B Cell lymphoma with a relationship with EB virus. Nodal and extra nodal disease. Typical look is well defined pulmonary nodules/mass, patchy air space consolidation, halo sign, interlobular septal thickening.
AIDS RELATED PULMONARY LYMPHOMA
Second most common lung tumour in AIDS (Kaposi first). High grade NHL. Relationship with EBV. CD4 <100. Presentatin variable, nodules 1-5cm. AIDS patient with lung nodules, pleural effusion and lymphadenopathy = lymphoma
Pulmonary NHL vs HL
SECONDARY NHL
80-90% cases. 45% have intrathoracic disease at presentation. 25% have pulmonary parenchymal disease. Pulmonary involvement in absence of mediastinal disease frequently occurs.
SECONDARY HL
10-20% cases. 85% have intrathoracic disease at presentation. 40% have pulmonary parenchymal disease. Pulmonary involvement almost always associated with intrathoracic LN enlargement.
Nukes
THALLIUM
Potassium analog, anything with functioning Na/K/ATPase are alive and will be thallium positive.
GALLIUM
Iron analong. Iron is inflammatory marker acute phase reactant. Things that are inflamed - infection, active sarcoid, most cancers are Gallium HOT.
Lymphoma is Gall and Thall HOT
kaposi is Thall HOT Gall COLD
Congenital
POLAND SYNDROME
Unilateral absence of pec muscle. Causes hyperluscent lung. Can have other arm/hand abnormalities.
BRONCHIAL ATRESIA
Congenital obliteration of short segment of lobar, segmental or subsegmental bronchus near origin (usually apical posterior LUL). Vascular insult in utero. Nodule near hilum which is mucoid impaction in blind ending brochus. Hyperluscent segment. Asymptomatic unless receurrent pneumonia. Primary differential is endobronchial tumour
AVM
Can occur sporadically. For purpose of MCQ, think HHT (Osler Weber Rendu). Usually in lower lobe and can be a source of right to left shunt. (stroke and brain abscess). Treat once afferent vessel is 3mm.
PERSISTENT LEFT SVC
Most common congenital venous anomaly of chest. Confusing PICC/Pacemaker line location. Drains into coronary sinus or rarely into LA.
SWYER JAMES
Unilateral lucent lung. Typically after viral lung infection in childhood resulting in post infectious obliterative bronhiolitis. Size of effected lobe is smaller than than the other.
HORSESHOE LUNG
Connects at posterior basilar segments of lower lobes behind heart. Associated with scimitar
Cystic lung disease
PULMONARY LCH
Smoker, young 20-30. Centrilobular nodules upper lobe predominance. Nodules eventually cavitate into cysts which begin thin walled then get thicker. Bizarre shaped cysts when they merge. Upper/mid zone predominant. 50% case spontaneously resolve, especially if stop smoking. Spares costophrenic angles.
LYMPHANGIOMYOMATOSIS LAM Tuberous sclerosis (AMLs, tubers) and childbearing age women. Estrogen dependent. Thin walled round cysts. Uniform or diffuse distribution. Usually progressive despite attempts at hormonal therapy (tamoxifen). Association with chylothorax
BIRT HOGG DUBE (BHD)
Bilateral oncocytomas, chromophobe RCC. Bunch of gross skin stuff. Thin walled oval floppy cysts. Lower zone predominant.
Lymphocytic Interstitial Pneumonitis LIP
Benign lymphoproliferative disorder with infiltration into lungs. Association with autoimmune (SLE, RA, SJOGRENS) Sjogrens is in 25% cases. Other one is HIV which is LIP in young patient. Also association with Castlemans. Cystic lung disease is usually thin walled deep within lung parenchyma and predominantly with Sjogrens.
LIP = Sjogrens and HIV (kids)
Cysts and GG nodules
Pneumocystis pneumonia PCP
Most common opportunistic infection in AIDS. GG, predominantly in hilar and mid lung zones. Pneumatocoeles in 30% cases. May have bilateral thin walled upper lung predominant cysts. Gallium shows diffuse uptake.
AIDS and GG lungs = PCP
Cystic form of PCP (after aerosolized prophylaxis) has apical predominant thin walled cysts. High risk for PTX
Vanishing lung syndrome
Idiopathic cause of giant bullous emphysema resulting from avascular necrosis of lung parenchyma and hyperinflation. Favours bilateral upper lobes and is defined as bullous disease occupying at least one third of a hemithorax. Usually young man. 20% have alpha 1 antitrypsin deficiency. Tension PTX is complication.
RF are smoking, alpha 1 antitrypsin deficiency, male
Honeycomb lung
Should think of UIP straight away. However, honeycombing is seen with a variety of causes of end stage fibrotic lung processes. Tightly clustered subpleural cysts. Walls often thick.
Emphysema
Permanent enlargement of the airspaces distal to the terminal bronchioles accompanied by destruction of the alveolar wall without clear fibrosis.
CXR
Flattening of hemidiaphragms. AP diameter increases. Retrosternal clear spaces enlarges.Paucity or pruning of vessels.
COPD trivia
Diffuse coronal narrowing of trachea, sparing extrathoracic portion. Can have surgery to remove bad lung (volume reduction).
CENTRILOBULAR
By far most common. Asymptomatic elderly. Apical to basal gradient favouring upper zones of each lobe. Focl lucencies within secondary pulmonary lobule often with central dot representing central bronchovascular bundle. Central dot sign is buzzword. Dominant in smokers
PANLOBULAR
Favours lower lobes. More uniform distribution accross parts of secondary pulmonary lobule. Associatin with alpa 1 antitrypsin deficiency. Ritalin lung can have this pattern. Lower lobe predominance. Smoking accelerates process.
PARASEPTAL
Adjacent to pleura and septal lines with peripheral distribution within secondary pulmonary lobule. Affected lung is almost always subpleural and demonstrates small focal lucencies up to 10mm. Looks like honeycombing but less than 3 bubbles thick. Smoking vs idiopathic
Pneumoconiosis
Inhaled and upper lobe predominant. Centrilobular or perilymphatic nodules
Asbestos
ASBESTOS EXPOSURE
Similar to UIP. Parietal pleural thickening. Asbestosis is fibrosis associated with exposure not the the actual exposure. 20 year latency between initial exposure and develoment of lung cancer or mesothelioma. Association with extrapulmonary cancer including peritoneal mesothelioma, GI/renal/laryngeal cancer and leukemia. benign pleural effusions earliest phenomenon at 5 years past exposure.
BENIGN ASBESTOS RELATED CHANGES
Pleural effusion earliest and most common. Pleural plaques can develop 20-30 years after with calcs at 40 years. Plaques spare apices and costophrenic angles. Round atelectasis sometimes called asbestos pseudotumour
Malignant mesothelioma
Most common cancer of pleura. 80% have had asbestos exposure. Development not dose dependent. Lag time 30-40 years.
Circumferential pleural thickening extending to medial pleura near heart. Pleural thickness >1cm. Extension into fissure suggestive.
Silicosis
Miners and quarry workers.
SIMPLE
Multiple nodular opacities favouring upper lobes with egg shell calcification in LNs. Also get perilymphatic nodules
COMPLEX
Progressive massive fibrosis. Large masses in upper lobes with radiating strands. Can sometimes cavitate - raises suspicion of TB.
SILICOTUBERCULOSIS
Silicosis raises suspicion of TB 3 fold. If see cavitation, consider TB
Coal workers pneumoconiosis
Result of exposure to washed coal. Simplae and complicated form. Increased risk of TB.
SIMPLE
Multiple nodular opacities with calcifications showing a central dot. Perilymphatic distribution.
COMPLEX
Progressive massive fibrosis similar to silicosis.
Secondary pulmonary lobule
Basic unit of pulmonary structure and function. Smallest part of lung that is surrounded by connective tissue. In the middle runs a terminal bronhchiole with an accompanying artery. Around the periphery runs veins and lymphatics.
Nodules
PERILYMPHATIC
Subpleural and peribronchovascular.
Sarcoid, lymphangitic spread, silicosis
RANDOM
Pleural nodules, no predominance
Miliary TB, mets, fungal
CENTRILOBULAR
No pleural nodules
Infection, RB-ILD, Hypersensitivity pneumonitis
Interlobular septal thickening
Reticular abnormality that outlines the characteristic shape and size. Kerley B lines on CXR
SMOOTH/SYMMETRIC
Pulmonary oedema
NODULAR/ASYMMETRIC
Lymphangitis carcinomatosis
Honeycombing
Cystic areas of lung destruction in a subpleural location. Hallmark of UIP. Paraseptal emphysema is a mimic but distinction made by how many rows of bubbles
One row = paraseptal emphysema
2-3 rows = honeycombing
Idiopathic interstitial pneumonias
CAUSE Idiopathic Collagen vascular disease Medications Inhalation
ANSWER
UIP - bad prognosis
Not UIP - does ok
Usual interstitial pneumonia UIP
Most common ILD. If idiopathic, IPF. Reticular pattern with reduced lung volumes.
Traction bronchiectasis Honeycombing Heterogenous Reticular abnormalities Subpleural and basal predominant
Fibrosis and cancer
Pulmonary fibrosis is RF for cancer.
Cancer favours lower lobes in fibrosis
Favours interface between fibrotic syts and normal lung, Progressive wall thickening or developing nodule within a cyst is suspicous for cancer.
Non specific interstitial pneumonia NSIP
Less common than UIP. Homogenous inflammation or fibrosis (UIP heterogenous). Common in collagen vascular disease (esp scleroderma) and drug reactions. Cellular or fibrotic
Ground glass Gradient less obvious but still lower lobes Homogenous histology Micronodules Subpleural sparing
Lower lobe posterior peripheral predominance with subpleural sparing in 50%. Immediate subpleural sparing is highly suggestive. Ground glass is NSIP equivalent of honeycombing.
RB-ILD and DIP
Smoking related diseases.
RB-ILD
Apical centrilobular ground glass nodules. Upper lobe predominant. Respiratory bronchiolitis and symptoms = RB-ILD.
DIP (desquamative interstitial pneumonia)
More diffuse GGO with patchy or subpleural distribution. 50yo heavy smokers. Peripheral lower lobe predominant GGO with small cystic spaces
Sarcoid
Multi system disease that creates non-caseating granulomas. 20-40yo. lungs most commonly affected 90%.
Acute sarcoid is Lofgren syndrome. Bilateral hilar LN enlargement, arthritis (ankles) and erythema nodosum.
Mediastinal LNs seen 60-90% in 1-2-3 pattern (bilateral hilar and right paratracheal. Perilymphatic nodules with upper lobe predominance. Late changes include upper lobe fibrosis and traction bronchiectasis. Late stage can get aspergillomas.
CXR staging 0 = normal 1 = Hilar/mediastinal LNs only 2 = Nodes and parenchymal disease 3 = parenchymal disease 4 = end stage fibrosis
CHF
Can mimic ILD on CXR. CCF can occur due t cardiac failure, fluid overload, high resistance in circulation.
STAGE 1
Redistribution. Cephalization of vessels, big heart, big vascular pedicle.
STAGE 2
Interstitial edema. Kerley lines, peribronchial cuffing, less distinct contour of central vessels.
STAGE 3
Alveolar oedema. Airspace fluffy opacity Pleural effusion
Right heart failure
Less common than LHF. LHF is most common cause of RHF. LHF causes pulmonary venous HTN which causes pulmonary arterial HTN which causes RHF.
Also can be caused by chronic PE, right isded valve issues (tricuspid regurg).
Imaging sees dilated azygous vein, RA enlargement, SVC dilatation, ascites, big liver and contrast reflux into hepatic veins.
Swan Ganz catheter
Used to measure pressure in LA, evaluate cardiac output and help cardiogenic vs non cardiogenic ARDS forms of pulmonary oedema, Catheter normally positioned between MPA and interlobar arteries (can be prox right or left MPA).
Tip too far out can cause pulmonary infarcts. Too far in can cause arrythmias
Lung transplant
For end stage pulmonary disease.
IMMEDIATE <24 hours
Donor recipient size mismatch
Hyperacute rejection
EARLY 24 hours - one week
Reperfusion injury
Air leak/persistent pneumothorax
INTERMEDIATE 8 days - 2 months
Acute rejection
Bronchial anastomotic complications
LATE 2 - 4 months
CMV infection
LATER >4 months Chronic rejection Cryptogenic organizing pneumonia PTLD Upper lobe fibrosis
Transplant continued
CHRONIC REJECTION/BRINCHIOLITS OBLITERANS
Major late complication, affects at least half of the transplants at 5 years. Bronchiectasis, bronchial wall thickening, air trapping, and interlobular septal thickening. Air trapping on expiration after 6 months is chronic rejection
RECURRENCE OF PRIMARY
Sarcoid most common recurrent primary around 35%
LUNG CANCER AFTER TRANSPLANT
Native lung still diseased. Highest rate with pulmonary fibrosis. Most common RF heavy tobacco
Pulmonary alveolar proteinosis PAP
Aunt minnie. Crazy paving (interlobular septal thickening with ground glass. Primary 90% or secondary 10%. Secondary causes are cancer or inhalation (silico-proteinosis).
Increased risk of nocardia infections. Smoking is strongly associated. Can progress to pulmonary fibrosis. Treatment is bronchoalveolar lavage.
CRAZY PAVING
Interlobular septal thickening and GGO. Isnt always PAP. Differential includes common things like oedema, haemorrhage, BAC, acute interstitial pneumonia and COVID.
Lipoid pneumonia
Endogenous vs exogenous
EXOGENOUS
Seen in older people who drink/aspirate mineral oil. Can also be seen with aspiration of vegetable oil or other animal oils. Low attenuation/fat density in consolidation.
ENDOGENOUS
More common results from post obstructive processes. Build up of lipid lade macrophages.
Organizing pneumonia
Used to be called BOOP. Granulation tissue deposition within the alveolar spaces secondary to fibroblast proliferation. Responds to steroids and has good prognosis. Reverse halo sign is classic, consolidation around GGO centre.
Idiopathic, prior infection, drugs (amiodarone), collagen vascular disease, fumes etc.
Persistent symptoms following treatment for pneumonia.
Patchy air space opacification or GGO in a peripheral or peribronchial distribution. Opacities irregular in shape. Both OP and Chronic eosinophilic pneumonia can present as peripheral consolidation.
Chronic eosinophilic pneumonia
Idiopathic or with known antigen. Peripheral eosinophilia usually present. Asthma in 50%. Peripheral consolidation. Peripheral GGO or consolidation. Upper lobes favoured.
Halo signs
HALO Nodule with ground glass in it. Represents haemorrhage /invasion into surrounding tissues. Invasive aspergillosis is classic. Haemorrhagic mets. BAC Wegeners
REVERSE (ATOLL) Central ground glass with rim of consolidation COP is classic TB Pulmonary infarct Invasive funga and Wegeners COVID
Hypersensitivity pneumonitis
Common. Inhaled organic antigens. Acute, subacute and chronic stages.
SUBACUTE
Patchy GGO. Ill defined centrilobular ground glass nodules. Mosaic perfusion and air trapping.
CHRONIC
UIP with air trapping.
Tracheal diseases
Does it involve posterior membrane? Is it focal or diffuse? Are there calcs?
SABER SHEATH
Coronal diameter less than 2/3 sagittal diameter. COPD. Normal wall thickness and bronchi size.
RELAPSING POLYCHONDRITIS
Spares posterior membrane. Diffuse anterior and lateral thickening. No calcs. Recurrent cartilage inflammation and pneumonia
POST INTUBATION STENOSIS
Focal subglottic circumferential stenosis
WEGENERS
Circumferential thickening focal or long segment. No calcs
TRACHEOBRONCHOPATHIA OSTEOCHONDROPLASTICA (TBO) Spares posterior membrane. Cartilagenous and osseous nodules within submucosa of tracheal and bronchial walls.
AMYLOIDOSIS
Irregular focal or short segment thickening which can involve posterior membrane. Calcs common
Tracheal diseases continued
SPARES POSTERIOR MEMBRANE
Relapsing polychondritis
Tracheobronchopathia Osteochondroplastica TBO
DOES NOT SPARE POSTERIOR MEMBRANE
Amyloid
Post intubation
Wegeners
Tracheal tumours
CARCINOID
Rare. Central endobronchial location. Slow growing and locally invasive. Cause obstructive symptoms, can cause haemoptysis. No association with smoking. Octreotide scan useful. Can be cold on PET. Can cause carcinoid syndrome
ADENOID CYSTIC
Favours upper trachea. Variable look. Not associated with smoking. 2nd most common tracheal malignancy.
SQUAMOUS CELL
Most common tracheal malignancy. Associated with smoking. Favours lower trachea.
METS
Usually direct extension
SQUAMOUS CELL PAPILLOMA
Most common benign tumour of trachea. Single papilloma think smoking. Multiple think HPV.
Cystic fibrosis
Sodium pump doesnt work and end up with thick secretions and poor pulmonary clearance. Damage by recurrent infections.
Bronchiectasis - begins as cylindrical and progresses to varicoid. Apical predominance Hyperinflation Pulmonary artery HTN Mucus plugging (finger in glove)
Abnormal mucus, cilia cant move
Normal sperm, absent vas deferens
Primary ciliary dyskinesia
Cilia dont work so cant clear secretions. Bilateral lower lobe bronchiectasis. Chronic sinusitis and impaired fertility (sperm cant swim, girls get ectopics). Chronic mastoid effusions and conductive hearing loss. 50% have Kartageners
CF vs PCD
CF
Abnormal mucus, cilia cannot move it
Normal sperm, absent vas deferens.
Upper lobe bronchiectasis
PCD
Normal mucus, cilia dont work
Abnormal sperm (cant swim), normal vas deferens
Lower lobe bronchiectasis
Rare cases
WILLIAMS CAMPBELL SYNDROME
Congenital cystic bronchiectasis from deficiency of cartilage in 4-6th order bronchi
MOUNIER KUHN
Tracheobronchomegaly
Massive dilatation of trachea.
Small airways disease
INFECTIOUS BRONCHIOLITIS
Tree in bud with air trapping.
RB-ILD
Smokers, centrilobular GG nodules, upper lobe preodminant
SUBACUTE HYPERSENSITIVITY PNEUMONITIS
Inhaling dust, cetrilobular GG nodules
FOLLICULAR BRONCHIOLITIS
RA and Sjogrens, centrilobular GG nodules
CONSTRICTIVE BRONCHIOLITIS
Viral, drugs, transplant, inhalation, air trapping.
Aspiration pneumonia
Stroke patients and alcoholics. Posterior segment of upper lobes and superior segment of lower lobes if supine. Bilateral basal lower lobes if upright. May favour right side. Can get empyema with subsequent bronchopleural fistula
Aspiration patterns
GASTRIC ACID
Mendelsons syndrome. Airspace opacity.
WATER/NEUTRALIZED GASTRIC ACID
Fleeting opacity which resolves in hours
GERMS/MOUTH BUGS
Real pneumonia, parapneumonic effusion, empyema, bronchopleural fistula
OIL
Lipoid pneumonia
Collagen vascular disease
LUPUS
Pleural and pericardial effusions. Can get shrinking lung but fibrosis uncommon
RHEUMATOID
Looks like UIP and COP. Lower lobes favoured. Reticulation with or without honeycombing. Consolidative opacities.
SCLERODERMA
NSIP pattern. Lower lobe predominant. Look for dilated fluid filled esophagous
SJOGRENS
LIP pattern. GGO with thin walled cysts
ANKYLOSING SPONDYLITIS
Upper lobe fibrobullous disease. Unilateral progressing to bilateral
Caplan syndrome
Rheumatoid arthritis and upper lobe predominant lung nodules. Nodules can cavitate. and may get pleural effusion
Shrinking lung
Progressive loss of lung volume in patients with Lupus. Either diaphragm dysfunction of pleuritic chest pain
Hepatopulmonary syndrome
Liver patients, SOB when sitting (opposite of CCF). Develop distal vascular dilatation in lung bases which dont taper normally. When sitting up these engorge and shunt blood making them SOB.
Wegeners granulomatosis (granulomatosis with polyangitis)
Triad of upper tract (nasal septal perforation)(cavitatory nodules), lung and kidneys.
Nodules with cavitation. Random distribution. GGO which may represent haemorrhage.
Goodpasture syndrome
Autoimmune pulmonary renal syndrome which favours young men. Non specific look with bilateral coalescent airspace opacity representing haemorrhage. Resolves quickly. If recurrent haemorrhage they can get fibrosis. Pumonary haemosiderosis can occur from recurrent episodes of bleeding making sall ill defined nodules
Pleural cacifications
Asbestos - 20-30 year lag, spares costophrenic angles Old haemothorax Old infection TB Extraskeletal osteosarcoma
Mesothelioma
Most common cancer of pleura. 80% have asbestos exposure. Lag time 30-40 years from exposure. Pleural rind all way around lung. Extension into fisure is suggestive
Solitaryfibrous tumour of pleura
Solitary tumour arising from visceral pleura. Not associated with asbestos, smoking or other pollutants. Can get very large and be a source of chest pain although mostly incidentally seen. Usually benign even when large.Hypertrophic osteoarthropathy occures 30%.
Pleural mets
Adenocarcinoma most likely to met to pleura. Lung is most common with breast 2nd and lymphoma 3rd. Pleural effusion most common manifestation.
Pleural lipoma
Most common benign tumour of pleura. Feel urge to cough. Will not erode rib. Differential is extrapleural fat but this will be bilateral and symmetric.
Pleural effusion
Needs to be 175cc on frontal to see them and t5cc on lateral. Transudative or exudative based on protein concentration.
SUBPULMONIC EFFUSION
Pleural effusion between lung base and diaphragm. Mor common on right with lateralization of the diaphragmatic peak.
ENCYSTED PLEURAL EFFUSION
Pleural fluid collect between layers of pleura creating oval appearance.
Empyema vs pulmonary abscess
EMPYEMA
Lentiform shape. Split pleura sign. Treated with chest tube. Infection pleural effusion. Enhancement of pleura, septations or gas. EMPYEMA NECESSITANS eats through chest wall into soft tissues. TB or actinomyces.
PULMONARY ABSCESS
Round. Claw sign. Not treated with chest tube due to risk of bronchopleural fistula.
Diaphragmatic hernia
Acquired or congenital. Congenital are Bochdaek (back left) or Morgagni (front right). Traumatic more common on left as liver is protective.
Diaphragmatic paralysis
Idiopathic 70% time but can be from phrenic nerve cmpression from lung cancer. Normally right diaphragm higher. Fluoroscopic sniff test see paradoxical movement.
Anterior mediastinal masses
4 Ts Thyroid Teratoma Thymus Terrible lymphoma
Thymus
REBOUND
Can rebound from chemotherapy. Hot on PET
THYMIC CYST
Congenital or acquired. Acquired after thoracotomy, chemotherapy or HIV.
THYMOMA
Spectrum from non invasive to invasive to thymomic carcinoma. Calcs makes more aggressive. Carcinomas invade adjacent fat/structures. Can drop met to pleural and retroperitoneum.
THYMOLIPOMA
Fatty mass with interspersed soft tissue
Germ cell tumour
75% teratoma. Most common extragonadal germ cell tumour. Ocure in kids and adults 20-30. Benign but small risk of malignant transformation. Immature subtypes almost exclusively in men. Association of mature teratoma with Klinefelter. Usually 90% cystic with some fat. Can have calcs or teeth.
Pericardial cyst
Uncommon and benign. Usually right anterior cardiophrenic angle.
Fibrosing/sclerosing mediastinitis
Proliferation of fibrous tissue in mediastinum. Bot subtypes can cause SVC syndrome
GRANULOMATOUS
Classically by histoplasmosis. Others are TB and sarcoifd. Soft tissue mass with calcs infiltrating mediastinal fat.
NON GRANULOMATOUS
More rare. Idiopathic or as response to an autoimmune disease. Associated with retroperitoneal fibrosis. Lacks calcs and can enhance.
Bronchogenic cyst
Congenital and usually within mediastinum., usually subcarinal or less commonly intraparenchymal.
Lymphadenopathy
Mets, infection, reactive.
Mediastinal lipomatosis
Excess unencapsulated fat in patients with iatrogenic steroid use, cushings and obesity
Posterior mediastinal masses
NEUROGENIC
Most common posterior mediastinal masses are neurogenic. Includes schwannoma, neurofirboma and malignant peripheral nerve sheath tumours.
Extramedullary haematopoeisis is a response to failure of bone marrow to respond to EPO. Seen in CML, polycythemia vera, myelofibrosis, sickle cell ad thalasemia.
PE on CXR
Westermark sign: regional oligemia (translucency due to no vessels seen - central clot)
Fleischner sign: enlarged pulmonary artery
Hamptons hump: peripheral wedge shaped opacity
Pleural effusion: 30% of PEs
Acute vs chronic PE
ACUTE
Clot is central. Venous dilatation. Perivenous soft tissue oedema. Pleural effusion common. Sudden death from arrhythmia or acute RHF. CTPA exam of choice
CHRONIC
Clot if seen is more peripheral. Shrunken veins with collateral vessels. Calcs within thrmobi and venous walls. Mosaic attenuation. Pulmonary HTN. VQ superior to CT
Massive PE needs hypotension <90 SBP.
Right heart strain: Dilated RV with septal flattening or left bowing. Contrast felux hepatic veins
Pulmonary infarct mimic
Pulmonary infarct is wedge shaped opacity that resolves slowly but can cavitate. Differentials include cancer and TB.
Pulmonary veno-occlusive disease
Uncommon variant of pulmonary HTN that affects post capillary pulmonary vasculature. PAH and normal wedge pressure.
Pulmonary artery aneurysm
Iatrogenic from Swan Ganz.
Behcets lymphoma
Chronic PE
Hughes Stovin syndrome: Cause of pulm art aneurysms. Recurrent thrombophlebitis and Pulm art aneurysm and rupture
Rasmussen aneurysm: pseudoaneurysm secondary to pulmonary TB. Upper lobes in reactivation TB.
TOF repair: patch aneurysm from RVOT repair.
Pulmonary HTN
PRIMARY
Idiopathic, women in 20s. Uncommon
SECONDARY
Chronic PE. RHF/strain. Lung parenchymal problems (emphysema, fibrosis). COPD
IMAGING
Compare aorta and MPA. Calcs of central pulmonary arteries is Eisenmenger phenomenon. RV dilatation. Centrilobular GG nodules
Trauma
DIAPHRAGMATIC INJURY
Left side more common (liver protective). Most ruptures are radial and in posterolateral corner. Collar sign is waist like appearance of herniated organs.
TRACHEOBRONCHIAL INJURY
Uncommon. Within 2cm of carina. Close to carina causes pneumomediastinum rather than pneumothorax. Tracheal lacs are at juntion of cartilagenous and membranous portions of trachea.
MACKLIN EFFECT
Most common cause of pneumomediastinum in truama. Alveolar rupture from blunt trauma, air dissects along bronchovascular sheaths into mediastinum
BOERHAAVE
Rupture esophageal wall from vomiting resulting in pneumomediastinum/mediastinitis
FLAIL CHEST
3 or more segmental rib fractures or more than 5 adjacent. Paradoxical motion with breathing
Trauma continued
PTX
Dont miss tension. Inversion of flattening of ipsilateral diaphragm
MALPOSITIONED CHEST TUBE
Can be in parenchyma, most commonly if background lung disease or pleural adhesions. Bronchopleural fistula can occur.
HTX
Pleural fluid in trauma is probably blood. 35-70HU
EXTRAPLEURAL HAEMATOMA
Injury to chest wall without damage to parietal pleura. Persistent fluid collection after pleural drain/tube placement. Displaced extrapleural fat.
PULMONRY CONTUSION
Most common lung injury from blunt trauma. Alveolar haemorrhage without alveolar disruption. Non segmental ill defined areas of consolidation with subpleural sparing. Should disappear within 72 hours.
PULMONARY LACERATION
Tear in lung will look like pneumatocoele. Gas fluid level. Masked by surrounding haemorrhage early on. Laceration resolves more slowly than contusion.
AORTA
Injured most commonly at isthmus. Next is aortic root and diaphragm. Main mimic is ductus bump which is normal variant.
BLUNT CARDIAC INJURY
Haemopericardium in setting of trauma.
FAT EMBOLIZATION SYNDROME
Long bone fracture or rod placement. Fat embolized to lungs, brain and skin. 1-2 days after femur fracture. GG appearance without PE.
BAROTRAUMA
Positive pressure ventilation causing alveolar injury with air dissecting into mediastinum. Acute lung injury or COPD higher risk. Fibrosis protected as dont stretch.
Lines and devices
CENTRAL LINES
Abrupt bend near tip of cather at cavoatrial junction makes you think its in azygos. If on left of heart think either arterial or in duplicated SVC. Central lines are risk for SVC occlusion
ETT
Tip should be 5cm from carina. Tip will go down when chin tucked. Tube in right main bronchus most common problem which can lead to left lung collapse. Can purposefully intubate one lung if massive pulmonary hamorrhage in the other.
INTRA-AORTIC BALLOON PUMP IABP
Cardiogenic shock to help with diastolic augmentation. Provides back pressure to vessels of arch get back perfused. Used to decrease LV afterload and increase myocardial perfusion. Balloon should be prox descending aorta. below origin of LSA. Complications are dissection and obstruction of LSA
Cardiac conduction devices
Pacemakers, implantable cardiac defibrillator or mixed
RV lead: cross midline on frontal
RA and RV leads: anterior on lateral
LV lead: posterior on lateral
RA lead: courses down then back up to go into RA appendage
Most commonly fractured in region of clavicle and first rib.
Twiddler syndrome when geenrator gets flipped/rotated in pocket.