Chest

Anatomy

• Saber sheath trachea => coronal diameter of the trachea is narrowed to coronal/sagittal ration of < 0.6. Seen in patients with COPD.

• Subsegmental anatomy:

  • Secondary lobule is comprised of three to five pulmonary acini (supplied by three to five terminal bronchioles.)

    • Pulmonary acinus is comprised of respiratory bronchiol, alvoelar duct, alveolar sacs.

  • Interlobular septa separate secondary lobules from each other.

• Fissures

  • Superior accessory fissure => separates superior segment from the basal segments of the lower lobe.

  • Inferior accessory fissure (10-20%)

  • Azygous accessory fissure (0.4%)

• Ligaments

  • Inferior pulmonary ligament => extends from hilum superiorly to level just above the hemidiaphragm.

    • Contains inferior pulmonay vein.

  • Pericardiophrenic ligament => seen along posterior side of the right heart border.

    • Contains phrenic nerve and pericardiophrenic vessels.

• Bronchial arteries

  • One right sided

    • Usually arises at T5-T6 level (level of tracheal carina).

  • Two left sided

• Pulmonary interstitium

  • Axial interstitium

    • Extends from hila to cetrilobular regions and envelopes bronchovascular bundles

    • Thickening is seen as peribronchial cuffing.

  • Peripheral interstitium => subpleural interstitium and interlobular septa

    • Contains pulmonary veins and lymphatics

    • Thickening is seen as thickened fissures and Kerley B lines.

  • Intralobular interstitium bridges centrilobular and peripheral compartments.

    • Thickening may account for some cases of ground glass opacities.

• Canals of Lambert => bridge preterminal bronchioles

• Pores of Kohn => interalveolar channels

Mediastinum

• Situs inversus

  • Kartegener’s syndrome => immotile cilia syndrome (respiratory infections and male sterility) + situs inversus

• Absence of pericardium

• Thoracic inlet

  • Thyroid

    • Goiter

    • Thyromegaly due to thyroiditis

    • Malignancy

  • Parathyroid

    • Hyperplasia

    • Adenoma

    • Carcinoma

  • Lymphoma

  • Lymphangioma

• Cardiac

  • Anatomy

    • Coronary anatomy

      • RM => PDA + R marginal

      • LM

        • LAD => diagonal

        • LCx => obtuse marginals

    • RA

      • IVC => eustachian valve

      • Coronary sinus => thebesian valve

  • Lipomatous hypertrophy of interatrial septum

  • Arrhythmogenic right ventricular dysplasia

    • Replacement of right ventricular myocardium with fat or fibrous tissue

    • Focal wall thinning and aneurysm may also be seen

  • Cardiac aneurysm

    • False aneurysm => inferoposterior, narrow neck

    • True aneurysm => anteroapical, wide neck

  • Sinus of Valsalva aneurysm

    • Associated with aortic regurgitation

  • Mirror image right arch

    • Associated with TOF and truncus arteriosus

  • Mitral valve prolapse

    • In Marfan syndrome congenital prolapse occurs in the mitral and tricuspid valves

  • LAE in adult

    • Mitral stenosis

      • No cardiomegaly

    • Mitral regurgitation

      • Cardiomegaly

  • RAE in a female

    • ASD

  • Unilateral pulmonary arterial enlargement

    • Pulmonary stenosis

    • Pulmonary artery aneurysm

  • Central pulmonary enlargement

    • Primary pulmonary hypertension

    • Eisenmerger physiology

  • Pulmonary enlargement including peripheral vessels

    • Left-to-right shunts

      • ASD

      • VSD

      • TAPVR

• Anterior mediastinum

  • Peds => cystic hygroma

  • Thymus

    • Thymoma (age > 40)

      • Drop metastses to ipsilateral pleura can be seen with invasive thymoma

    • Thymolipoma

    • Thymic cyst

    • Thymic hyperplasia

    • Thymic neuroendocrine tumors (carcinoid)

    • Thymic carcinoma

  • Lymphoma

  • Germ cell tumors

  • Thyroid

  • Parathyroid

  • Mesenchymal tumors

    Lipoma	Hemangioma
    Liposarcoma	Leiomymoma
    	Hemangiosarcoma

  • Cardiophrenic angle masses

    • Epicardial fat pad

    • Lipoma

    • Pericardial cyst

    • Foramen of Morgagni hernia

• Middle mediastinum

  • Lymph node enlargement

    • Infection

    • Malignancy

      • Metastases

        • Bronchogenic carcinoma

      • Lymphoma

      • Leukemia

      • Kaposi’s

    • Idiopathic

      • Castelmans

      • Sarcoidosis

      • Angioimmunoblastic lymphadenopathy

  • Foregut cysts

    • Bronchogenic cyst

      • Subcarinal and right paratracheal are most common.

      • Homogenous near water attenuation

  • Pericardial cyst

  • Tracheal lesions

  • Vascular

• Posterior mediastinum

  • Neurogenic

    Peripheral	Ganglia	Paraganglia
    Neurofibroma	Ganglioneuroma	Chemodectoma
    Schwannoma	Neuroblastoma	Pheochromocytoma
    	Ganglioneuroblastoma

  • Esophagus

  • Foregut cysts

    • Enteric

    • Neurenteric

  • Vertebral

  • Lateral thoracic meningocele

  • Pancreatic pseudocyst

  • Non-Hodgkins lymphoma

  • Extramedullary hematopoesis

• Diffuse mediastinal disease

  • Infection

  • Chronic sclerosing fibrosing mediastinitis

  • Hemorrhage

  • Medistinal lipomatosis

  • Malignancy

• Pneumomediastinum

Hilum

• Large

  • Unilateral enlargement

    • Infection

      • TB

    • Malignancy

      • Small cell carcinoma

    • Pulmonary artery enlargement

    • Bronchogenic cyst

  • Bilateral hilar enlargement

    • Sarcoidosis

    • Infection

      • TB

      • Fungal: histoplasmosis, coccidiomycosis

      • Bacillus anthracis

      • Yersenia pestis (plaque)

    • Malignancy

    • Berylliosis, silicosis

    • Bilateral pulmonary arterial enlargement

• Small

  • Unilateral

    • Hypoplasia or absence of pulmonary artery

    • Swyer-James

    • Hypoplastic or hypogenic lung

    • Compression or invasion

      • Cyst

      • Neoplasm

      • Fibrosing mediastinitis

    • Lobar resection

  • Bilateral

    • Emphysema

    • Pulmonary outflow obstruction

      • Fibrosing mediastinitis

      • Tetralogy of Fallot

      • Valvular pulmonic stenosis

      • Ebsteins anomaly

Trachea

• Tracheal narrowing

  • Saber-Sheath trachea (COPD)

  • Amyloidosis

  • Tracheobronchopathia Osteochondroplastica

    • Multiple submucosal osseous and cartilagenous deposits within trachea and bronchi of elderly men

    • Lesions arise as cartilage enchondromas

    • Calcified plaques involve anterior and lateral walls of the trachea

    • Posterior wall is spared in contrast to amyloid

  • Relapsing polychondritis

    • Systemic autoimmune disorder of the cartilage

• Tracheal dilatation

  • Tracheobronchomegaly (Mournier-Kuhn syndrome)

    • Congenital disorder of the elastic and smooth muscle components

    • Associated with Ehlers-Danlos syndrome

    • Trachea measured more than 3 cm

  • Tracheobronchomalacia

    • COPD

    • Chronic bronchitis

    • Cystic fibrosis

    • Relapsing polychondritis

• Tracheal neoplasms

  • Benign

    • Chondroma

      • Arises from cartilage

      • Stippled cartillagenous calcification on CT

    • Fibroma

    • Squamous cell papilloma

      • Young age (HPV)

      • Mucosal

      • Papillomatosis of the lung if causative agent spreads via bronchi

    • Hemangioma

      • Cervical trachea

      • Young age

    • Granular cell myoblastoma

      • Arises from neural elements

  • Malignant => 90% of primary tumors of the trachea in adults are malignant

    • Squamous cell carcinoma (most common) => 50%

    • Adenoid cystic carcinoma (cylindroma) => 40%

      • Arises from salivary glands

      • Involves posterolateral wall of distal 2/3 of the trachea or main or lobar bronchi

    • Mucoepidermoid carcinoma, carcinoid, lymphoma, small cell carcinoma, leiomyosarcoma, fibrosarcoma, chondrosarcoma

Bronchi

• Congenital

  • Bronchial stenosis or atresia

    • Mucus filled dilated bronchus (mucocele) with distal lung hyperlucency (from collateral air drift)

    • Apicoposterior segment of LUL most commonly involved

• Broncholithiasis

  • Calcified peribronchial lymph nodes erode into bronchial lumen

• Bronchiectasis

  • Three groups

    • Cylindrical

    • Varicose

    • Saccular

  • Causes

    • Bronchial stenosis or atresia

    • Cystic fibrosis

      • Elevated Na+ in the sweat

      • Infertility more common in males

    • Dysmotile cilia syndrome

    • Postinfectious

    • Allergic Bronchopulmonary Aspergillosis

    • Bronchial obstruction

    • Peribronchial fibrosis

• Bronchial neoplasms

  • Benign

    • Hamartoma

      • Fatty center covered by fibrous tissue

  • Malignant

    • Carcinoma

    • Carcinoid

      • Kulchitzky cell spectrum KCC-1 (low-grade) to KCC-3 (highly malignant)

      • No FDG avid

    • Gland neoplasms

    • Adenoid cystic carcinoma

    • Mucoepidermoid carcinoma

• Small airway disease

  • Bronchiolitis

  • Bronchiolitis obliterans

Lungs

• Distribution

  • Upper lungs

    • EG

    • Sarcoid

    • Silicosis

    • TB or histo

    • Brochiectasis from CF

  • Basilar

    • Asbestosis

    • Scleroderma

    • Rheumatoid

    • UIP, DIP

• Opacity

  • Air space

    • Acute

      • Pulmonary edema

        • Cardiogenic

        • Non-cardiogenic

          • ARDS

          • AIP

      • Inflammation

      • Hemorrhage

    • Chronic (GAB)

      • Granulomatous diseases

      • Alveolar proteinosis

      • Bronchioloalveolar carcinoma (other neoplasms).

  • Reticular

    • Acute

      • Interstitial edema

      • Inflammatory: viral, mycoplasma, PCP

    • Chronic

      • Scleroderma

      • Rheumatoid

      • UIP, DIP, LIP

      • LCH

      • Sarcoidosis

      • IF

      • Collagen vascular diseases (scleroderma, SLE)

  • Nodular (SESWEP)

    • Silicosis (large or fine)

    • LCH (fine)

    • Sarcoidosis (fine)

    • Wegener’s (large)

    • Eosinophilic pneumonia (peripheral)

    • Papillomatosis => nodular opacities with cavitations

  • Atelectasis

    • Mechanism

      • Obstrutive

      • Passive – mass effect from pleural space. Compressive – intrapulmonary process

      • Cicatricial – parenchymal fibrosis results in volume loss

      • Adhesive – surfactant deficiency

    • Extent

      • Lobar

      • Segmental

      • Subsegemental

      • Rounded

    • Location (RUL, RML, RLL, LUL, LLL)

• Lucency

  • Focal

    • Congenital

      • Bronchogenic cysts

      • Intrapulmonary sequestration

    • Bronchiectatic cysts

    • Cavity wall should be more than 1mm thick

      • Multiple cavities can result from necrosis after infection

      • TB, histoplasmosis, coccidiomycosis

      • Metastases

      • Vascular occlusions

        • Thromboembolism

        • Septic embolism

        • Vasculitis

          • Wegeners

          • Rheumatoid

    • Bulla = >1 cm with wall <1mm

      • Type 1 => Superficial, narrow neck

      • Type 2 => Parenchymal, vascularity present

      • Type 3 => Deep intraparenchymal

    • Air cyst = wall >1mm thick

      • Traumatic air cyst

      • Bronchiectatic cysts

    • Bleb = <1cm within layers of visceral pleura

    • Pneumatocele = distended air spaces

      • Healing phase of PNA

      • Post-traumatic pneumatocele from pulmonary laceration

    • PE => Westermark sign

      • Ischemic necrosis can result in a cavity

  • Diffuse

    • Unilateral

      • Swyer-James syndrome = adenoviral infection, asymmetric obliterative bronchiolitis, air trapping, unilateral pulmonary artery hypoplasia

    • Bilateral

      • Emphysema

        • Pathologic classification

          • Centrilobular

          • Panlobular

            • Alpha-1-antitrypsin deficiency

          • Paraseptal

          • Paracicatricial

      • Asthma

• HRCT

  • Interlobular (Septal) thickening (ELIS)

    • Edema

    • Lymphangitic spread

    • IPF

    • Sarcoidosis

  • Intralobular

    • IPF

    • NSIP

    • Collagen vascular disease

    • HP – chronic

    • Sarcoidosis

  • Nodular

    • Perilymphatic (supleural and peribronchovascular) (SSL)

      • Sarcoidosis

      • Silicosis, Beryliosis

      • Lymphangitic spread

    • Centrilobular (HER SIP)

      • HP

      • LCH

      • RB

      • Sarcoidosis

      • Infection (via endobronchial spread, including TB)

      • Pneumoconiosis

    • Random (HM)

      • Hematogenous metastasis

      • Miliary TB

  • Cystic

    • IPF

    • LAM

    • LCH

    • LIP

    • DIP

    • PCP

    • BAC

  • Ground glass

    • HP

    • DIP

    • AIP

    • NSIP

    • Connective tissue disease

      • SLE

    • Drug induced

    • Hemorrhage

  • Consolidation

    • COP

    • Eosinophillic PNA – chronic

    • Lymphoma

    • BAC

    • Acute disease

  • Mosaic

    • Small airway disease

    • Pulm vascular disease

• Lung malformations

  • Bronchopulmonary sequestration

  • Bronchogenic cysts

  • Congenital cystic adenomatoid malformation

  • Pulmonary agenesis (lungs and associated tissues are absent)

  • Pulmonary aplasia (no lung parenchyma, but rudimentary main bronchus present)

  • Scimitar (Radiology 210 (1): 288)

    • Scimitar syndrome => always right-sided lobar hypoplasia or aplasia

      • Combination of

        • Anomalous venous drainage of all or most of the right lung to the right atrium or IVC

        • Hypoplasia of the right lung

        • Systemic arterial collateral vessels to the right lung

      • Associated with sequestration, cystic adenomatoid malformation, foregut malformations, ASD, VSD, TOF, PDA, accessory diaphragm, horseshoe lung

    • Scimitar vein

      • Vertical curvilinear vein that drains all or portion of the right lung to the right atrium or IVC

    • Scimitar sign

      • Scimitar vein visible on a chest radiograph

  • Unilateral pulmonary hypoplasia (normal main bronchus, rudimentary lung)

  • Congenital lobar emphysema

    • Results from any check valve bronchial obstruction

    • Hyperlucent lobe (as opposed to hyperlucent segment in bronchial stenosis or atresia)

  • Congenital bronchial atresia

• Vascular malformations

  • Pulmonary AVM

    • Osler-Weber-Rendu disease

  • Scimitar vein

  • PAPVD

  • PA hypoplasia/atresia

• Inflammation

  • Lobar PNA

    • Starts in alveolar spaces, spreads through pores of Kohn

  • Broncho PNA

    • Starts in the airway, spreads through canals of Langerhans

  • Interstitial PNA

    • Linear => viral, mycoplasma, PCP

    • Ground glass => PCP, CMV, Mycoplasma

    • Nodular

    • Miliary => TB, fungal

  • Nodular/mass

    • Round PNA

    • Lung abcess

    • Granulomatous infection

    • Actinomyces/Nocardia

    • Parasitic infection

  • Infection in immunocompromised patient

    • Lobar => bacterial, TB, parenchymal lymphoma

    • Nodular/cavities => bacterial, fungal (hematologic malignancy), malignancy (post-transplant lymphoproliferative disease, metastases)

    • Diffuse => PCP, viral (CMV, herpes), drug-induced, non-specific interstitial pneumonitis, hemorrhage, pulmonary edema

  • Complications of PNA

    • Lung abcess (spherical, destruction of adjacent parenchyma)

    • Empyema (lenticular, compression of adjacent parenchyma)

  • TB

    • Rasmussen aneurysm => pulmonary artery aneurysm in the tuberculous cavity.

    • Ranke complex is seen in primary TB

    • Ghon focus

  • Eosinophilic lung disease

• Pulmonary alveolar proteinosis

  • Chronic alveolar proteinosis can have interstitial pattern

• Alveolar microlithiasis

• Alveolar septal amyloidosis

• Pulmonary Edema

  • Nomenclature

    • Kerley’s A = thickening of central connective tissue

    • Kerley’s B = thickening of peripheral interlobular septa

    • Kerley’s C = network of thickened interlobular septa

  • Hydrostatic

    • PCWP 8 – 12 = nl

    • PCWP 12-18 = constriction of lower lobe vessels and enlargement of upper lobe vessels

    • PCWP 19-25 = loss of vascular definition, peribronchial cuffing, Kerley’s lines

    • PCWP > 25 = alveolar filling, perihilar and lower lung zones bilateral air space opacities

    • Distribution is even from central to peripheral with over lower lung zones

    • Vascular pedicle (width at the level of SVC and LSCA) is > 53mm on PA

  • Permeability (ARDS)

    • Leakage of protein rich edema fluid

    • Distribution is peripheral with normal vascular pedicle width and normal heart size

    • Progression

      • 12-24 hours: patchy peripheral air space opacities

      • Several days: Confluent bilateral air-space opacities with ABGram

      • First week may improve from increasing PPV

      • > 1 week: Coarse reticulonodular pattern

      • > 1 mos: resolves or irreversible pulmonary fibrosis develops

  • Neurogenic = massive sympathetic discharge

    • Hydrostatic and increased permeability

  • High Altitude

  • Reexpansion

  • RUL pulmonary edema

    • Preferential regurgitant flow into right upper lobe pulmonary vein in patients with severe mitral valve regurgitation

  • Acute upper airway obstruction

  • Amniotic fluid embolus

    • Acute cor pulmonale from sudden pulmonary arterial HTN after emboli obstruction of PA by mucin and fetal squames

  • Fat embolism

    • 24-72 hours after FX of a long bone

• Pulmonary hemorrhage

  • Autoimmune (Radiographics 20(6), 1623)

    • Goodpasture’s

      • Hemorrhages

    • Wegener’s

      • Granulomatous vasculitis of upper and lower airways, diffuse small vessel vasculitis and focal glomerulonephritis

      • Ill-defined nodular masses that cavitate in 50% of patients

    • SLA

    • Rheumatoid Arthritis

    • Polyarteritis nodosa

  • Idiopathic

• PE

  • Westermark sign= oligemia

  • Hampton’s hump = infarction

• Pulmonary artery HTN

  • PAP > 30

  • Calcifications on pulmonary arteries are rare but specific

  • Transverse diameter of pulmonary artery on PA CXR > 16 mm

  • Transverse measurement of main pulmonary artery on CT or MR > 28.6 mm

  • Idiopathic or primary pulmonary hypertension

    • Plexogenic pumonary arteriopathy => medial hypertrophy and intimal fibrosis obliterate muscular arteries. (Dilated vascular channels within periphery of the obliterated vessels produce plexogenic lesions seen on biopsy

    • Recurrent microscopic pulmonary emboli

    • Pulmonary venocclusive disease => transmission of increased pressure to arterial side results in medial hypertrophy and obliteration of vessels.

• Solitary Pulmonary Nodule

  • Primary lung vs. metastasis

    • In the absence of known primary maligancy, SPN is unlikely to be a metastasis

    • In patients with melanoma, sarcoma and testicular carcinoma, SPN is 2.5 times more likely to be a metastasis than a primary lung cancer

    • In patients with head and neck squamous cell carcinoma, a malignant SPN is 8 times more likely to be a primary lung cancer.

  • Calcification patterns

    • Benign

      • Central nidus

      • Laminated

      • Popcorn

      • Diffuse

    • If a nodule smaller than 9mm is seen on CXR, it is likely to be diffusely calcified and benign

    • In patient’s with history of bone malignancy, malignant SPNs may have benign calcification pattern

    • Malignant

      • Eccentric

      • Stippled

      • Amorphous

      • Diffuse

  • Enhancement pattern

    • Enhancement of less than 15 HU indicates benignity.

  • Size

    • < 5mm => Follow up in 1 year

    • 5-9 mm => 3, 6, 12, 24 serial CT scans or FNA

    • 1 cm => PET and contrast study

  • Differential

    • Malignant neoplasms

    • Pulmonary Hamartoma

      • Popcorn calcification

    • Bronchogenic cyst

    • Pulmonary AVM

    • NHL

    • Granular cell myoblastoma

    • Leiomyoma/Leiomyosarcoma

    • Fibroma/Neurofibroma

    • Lipomas

    • Hemangiopericytoma

    • Plasma cell granulomas

    • Lipoid PNA

• Multiple pulmonary nodules

  • Sarcoidosis

  • Neoplasms

    • Lymphoma

    • Osteosarcoma => spontaneous PTX

• Neoplasms

  • Bronchogenic carcinoma

    • Adenocarcinoma 35%

      • Peripheral nodule

      • Bronchoalveolar carcinoma is a subtype of adenocarcinoma

        • Produces mucin

        • Not FDG avid

        • Has ground glass appearance because the tumor grows along interstitium without invasion (lepidic growth).

    • Squamous cell carcinoma 25%

      • Hilar mass

      • Atelectasis

    • Small cell carcinoma 25%

      • Hilar mass

      • Mediastinal mass

    • Large cell carcinoma

      • Large peripheral mass

      • Giant cell carcinoma is a subtype of large cell carcinoma

    • Mixed cell carcinomas

      • Adenosquamous carcinoma

      • Carcinosarcoma

  • Carcinoid

  • Sarcoma

  • Blastoma

  • Lymphoma

  • Metastasis to lungs

    • SPN

      • Rectosigmoid carcinoma

      • Osteosarcoma

      • RCC

      • Melanoma

    • Multiple – findings suggestive of metastastatis vs granulomas

      • Feeding vessel

      • No calcifications (except if known osseous lesion exists, calcifications can be malignant)

      • Presence of large nodule with miliary nodules

    • Lymphangitic carcinomatosis

      • Breast, stomach, pancreas, prostate

• Iatrogenic lung disease

  • Drug reactions

    • Nitrofurantoin

    • Bleomycin

    • Alkylating agents (Cytoxan and busulfan)

    • Methotrexate

    • Amiodarone

  • Radiation induced lung disease

    • Doses of nore than 2000 rads

• Pneumoconiosis

  • Silicosis

    • Acute: Bilateral perihilar consolidations/ground glass opacities/centrilobular nodules

    • Classic: 2mm-5mm nodules in the upper and posterior portions of the lungs in centrilobular, paraseptal and subpleural regions, some maybe calcified. Egg shell calcifications maybe present in the hilar and subcarinal lymph nodes.

  • Coal worker pneumoconiosis

    • Appearance is similar to silicosis

  • Asbestosis

    • Fibrosis at the lung bases. Prone imaging maybe needed to differentiate fibrosis related to asbestosis from dependent atelectasis.

  • Berryliosis

    • Hilar lymph node enlargement (similar to sarcoidosis)

    • Small nodules along bronchovascular bundles or interlobular septa

  • Hard-metal pneumoconiosis

    • Diffuse interstitial fibrosis

  • Talcosis

    • Generalized haziness, nodulation and reticulation with characteristic sparing of costophrenic sulci and apices.

  • Siderosis

    • Small perihilar centrilobular nodules

    • Branching linear structures, which are related to deposition of iron oxide particles can be seen.

• Cystic changes

  • LAM – diffuse

  • EG – perdominantly involving upper lobes

    • Associated with tuberous sclerosis

Pleura

• Spontaneous PTX associated with

  • Osteosarcoma metastasis

  • Cystic fibrosis

  • LAM

• Pleural effusion

  • Infectious

  • Cardiovascular

  • Neoplastic

    • Bronchogenic carcinoma

    • Metastases

    • Lymphoma

  • Immunologic

    • SLE

    • RA

    • Sarcoidosis

  • Trauma

  • Abdominal disease

• Focal pleural thickening

  • Fibrosis from

    • PNA

    • PE

    • Asbestos exposure

    • Trauma

    • Chemical pleurodesis

    • Drug related pleural disease

  • Calcification

    • Prior hemorrhage

    • Prior empyema (TB)

    • Asbestos

      • Plaques are found in parietal pleura

  • Tumors

    • Localized fibrous tumors of pleura

      • Associated with hypertrophic pulmonary osteoarthropathy and hypoglycemia

    • Lipomas

    • Mesotheliomas

      • Benign (no association with asbestos exposure)

      • Malignant (associated with asbestos exposure)

    • Metastasis

      • Usually adenocarcinomas (lung and breast primaries), melanoma or invasive thymoma

• Diffuse pleural thickening

  • Smooth

    • Fibrothorax

  • Lobulated

    • Multiloculated pleural effusion

    • Pleural malignancy

      • Mesothelioma

      • Metastases

Diaphragm

• Congenital

  • Diaphragmatic hernias

    • Hiatal hernia

    • Foramen of Bochdalek

      • Site of embryonic pleuroperitoneal canal (posterior)

      • Hernias are usually seen on the left side because of protective effect of liver

    • Foramen of Morgagni

      • Least common type of diaphragmatic hernia

      • Invariably right sided cardiophrenic angle mass

• Trauma

  • Left-sided in 90% of the cases, because liver protects the right hemidiaphragm

Patterns

• Apical cysts

  • Langerhan’s cell histiocytosis

  • Lymphangioleiomyomatosis

Mediastinum

• Congenital abnormalities

  • Anomalous right subclavian artery

    • Passes behind esophagus

    • Diverticulum of Kommerrel

  • Right aortic arch (descending aorta is usually left sided)

    • Mirror image

    • Right arch associated with anomalous left subclavian artery

  • Double aortic arch

    • No innominate artery

    • Symmetric appearance of great vessels

  • Coarctation and pseudocoarctation

    • Pseudocoarctation – kinked and somewhat narrowed but no significant pressure gradient exists

    • Both are associated with congenital bicuspid aortic valve

• Aortic aneurysm

  • Ascending aorta more than 4 cm

• Aortic dissection

  • Stanford Type A (DeBakey I – entire, and DeBakey II) and Type B (DeBakey III)