Diagnostic Radiology of

Respiratory System

huilinzhao2013@163.com

Department of Radiology, Renji Hospital

Shanghai Jiao Tong University, School of medicine

赵辉林 Zhao Huilin

LEARNING OBJECTIVES

• 1. Knowledge degree: imaging methods of X-ray and CT

• 2. Master degree: X-ray and CT appearance of normal structure and basic lesion from respiratory system

• 3. Master degree: X-ray and CT appearance of pneumonia, pulmonary tuberculosis and lung cancer

• 4. Acquaintance degree: predilection site and radiologic appearance of mediastinal neoplasms

MAIN CONTENTS

• Examination methods

• Normal chest findings

• Essential lesions of chest

• X-ray、CT manifestation of bronchiectasis、pneumonia、lung abscess、pulmonary tuberculosis、pulmonary tumor and mediastinal tumor

Examination methods

of chest

---Introduction

General Examination Methods

a. Fluoroscopy

b. Chest X-ray filming

c. CT

•• PosteroanteriorPosteroanterior chest (Pchest (P--A)A)

Chest X-ray filmimg

Right Left

Lateral chestLateral chest

Chest X-ray filming

AnteroposteriorAnteroposterior

Used in weaken patientsUsed in weaken patients

Chest X-ray filming

•• Oblique chest Oblique chest

Chest X-ray filming

Normal Chest

a. The bony thorax

b. The soft tissues

c. The mediastinum

d. The diaphragm

e. Pleura

f. Trachea,bronchi

g. Lungs

h. Lung hilus

Normal anatomic structures

Nipple

Breast

The bony thorax

• Shoulder girdles

• Ribs

• Thoracic vertibral bodies

• Sternum

• Clavicles

1 2 3 4

5

6

7

8

9

10

11

12

Cervical rib

15

Bifurcation of rib

Fusion of ribsFusion of ribs

Pleura

• Parietal pleura

• Visceral pleura

• Major fissures

fissures on chest radiograph.

a. Horizontal fissure

b. Oblique fissure

lateral

Lung

.

• Lung fields

• Hilus

• Lung markings

Lung fields

•Inferior margin of 4th

rib

•Inferior margin of 2th

rib

Lung Hilus

• Blood vessls

• Bronchi structures

• Lymph vessls

• Two hili occupy 2nd - 4th

anteriorly intercost space.

• Left hilus is 1-2cm higher than right.

Lung markings

• Blood vessls

• Bronchi structures

• Lobe

• Segment

• Lobule

• Acinus

normal airway anatomy

Broncho-pulmonary segments

Right Left

Superior lobar bronchi Superior lobar bronchi

Apical segment Apicoposterior segment

Posterior segment Anterior segment

Anterior segment Superior lingular segment

Intermedial bronchus Inferior lingular segment

Middle lobar bronchi

Lateral segment

Medial segment

Inferior lobar bronchi Inferior lobar bronchi

Apical superior segment Apical superior segment

Medial basal segment Anteromedial basal segmeng

Anterior basal segment Lateral basal segment

Lateral basal segment Posterior basal segment

Posterior basal segment

Mediastinum

The mediastinum is divided by a line drawn horizontally from the sternal angle to the lower border of T4 into superior and inferior mediastina.The latter is further subdivided into anterior,middle and posterior mediastina.

• Superior

• Inferior

• Anterior

• Middle

• Posterior

Mediastinum

• Heart

• Blood vessels

• Trachea

• Main bronchus

• Esophagus

The diaphragm

• Separates the thorax from the

abdomen.

• The upper surface of the

diaphragm is smooth.

• The right dome lies in tenth

posterior rib,left is slightly lower.

• Costophrenic angles are sharp.

Systematic Approach

Hidden areas

Easily be overlooked:

apical zones

hilar zones

retrocardial zone

zone below the dome of diaphragm

CT CR/DR X-ray filming

Difference between X-ray filming and CT

• Normal chest CT

Inferior accessory fissure. Axial CT scan shows

the right inferior accessory fissure (larger

arrows), which separates the medial from the

other basilar segments of the right lower lobe,

and the left major fissure (smaller arrows).

Left minor fissure. Axial CT scan shows the left

minor fissure (solid arrow) separating the lingula

from the other upper lobe segments. The left

major fissure (dashed arrow) is shown more

posteriorly.

fissures on chest axial CT

What structure is indicated by the arrow?

a. Costal cartilage calcification

b. ScapulaScapula

c. Sternumc. Sternum

d. Thorax vertebrad. Thorax vertebra

SELF-ASSESSMENT QUESTIONS

Pulmonary basic lesions

a. Bronchial obstruction

b. Exudative consolidation lesion

c. Nodular lesion

d. Calcification

e. Cavity

f. Mass

g. Interstitial lesion

h. Pleural effusion

i. Pneumothorax

j. Pleural thickening and calcification

Bronchial obstruction

• Hyperinflaton and emphysema

• Obstructive atelectasis

Hyperinflaton and emphysema

• Intrinsic factors

Intraluminal neoplasm

Foreign body

Congenital or infectives stenossis

Edema

Blood clot

Spasmodic contraction

• Extrinsic factors

Obstructive emphysema

X-ray appearances

• The lungs show increased adiolucency.

• Windening of the intercostal spaces.

• Lung markings reduced.

• Mediastinum and heart become narrowed and elongated.

Emphysema

X-ray

CT

Emphysema

CT X-ray

• Bullae

Complete obstruction

from intrinsic or extrinsic causes

Obstructive atelectasis

Lobar atelectasis

X-ray findings

Triangle homogeneous shadow of increased

density and one-angle connect lung hilus.

Intercostal spaces narrowing.

Mediastinum shifted toward the

Diaphragm is elevated.

Adjacent and opposite lung may be compensatory

emphysema.

Lobar atelectasisLobar atelectasis

Superior lobar atelectasis Middle lobar atelectasis

Inferior lobar atelectasis Superior lobar atelectasis

A: PA chest radiograph of a man with right upper lobe bronchogenic carcinoma. The endobronchial tumor causes

collapse of the right upper lobe and upward displacement of the minor fissure (solid arrow). The tumor mass

produces a convex margin toward the lung at the right hilum (dashed arrow). The contour of the displaced fissure

and central mass creates a reverse S shape. Note the elevation of the right hemidiaphragm, another sign of right

upper lobe volume loss. B: CT of the chest shows tumor encasing and occluding the right upper lobe bronchus

(solid arrow) and collapse of the right upper lobe, with superior and medial displacement of the minor fissure

(dashed arrow).

Superior lobar atelectasis

Golden S sign

Inferior lobar atelectasis

shows partial loss of the contours of the hemidiaphragms

LOBAR ATELECTASISLOBAR ATELECTASIS

Inferior lobar atelectasis

shows downward and medial displacement of the left major

fissure. a triangular area of increased opacification over the left

heart, and loss of the left medial diaphragmatic contour.

complete collapse of the left lung.

The left hemithorax is completely opaque and the mediastinum is

shifted to the left.

Left lung collapse

Exudative and consolidated lesion

Air spaces are filled with exudative fluid,protein, cells, mainly by fluid.

Poorly defined border, low homogeneous density patch.

If the lesion becomes chronic then the density is increased.

Key-findings on the X-ray:

--- ill-defined homogeneous opacity obscuring vessels

--- Silhouette sign: loss of lung/soft tissue interface

--- Air-bronchogram

--- Extention to the pleura or fissure, but not crossing it

--- No volume loss

Consolidation --Lobar pneumonia

Consolidation

--lobar pneumonia

Diffuse Consolidation --heart failure

Proliferative lesion

Chronic infection of the lung may

develop intogranulomatous tissue.

Radiologically defined border nodule.

MiliaryMiliary nodulesnodules

F, 64y

Cough, renal tuberculosisCough, renal tuberculosis

history history

Fibrotic lesion

Healing of chronic infection, proliferative lesion of the lung .

X-ray findings

a. Strike,reticular, or linear lesion

b. Well-defined border,

somewhat rigid with high density

c. Diffuse pulmonary fibrosis, irregular,

reticular or honeycomb shadows.

Calcification

Well-demarcated border

Very high density

Varying shape

punctuated,massive or globular.

Mass

Most of masses are round or lobulated.

Benign tumor has a sharp contour.

Single lobulated mass with short,fine

spiculations is primary carcinoma.

Most of the multiple cotton ball-like masses

are metastatic tumors.

Non-tumorous lesions such as

tuberculoma,inflammatory pseudotumor,cyst.

Mass

Mass

Popcotton calcification

Collection of fat

Cavity

frequently arise within a mass or an area of

consolidation as a result of necrosis

Thick-walled cavity

Thin-walled cavity

Thick-walled cavity

Thick-walled cavity

Thin-walled cavity

Air containing space-cyst

differential diagnosis

• Cavity - lucency with a thick wall

• Cyst - lucency with a thin wall

• Emphysema - lucency without a visible wall

Interstitial lesion

It occurs around the bronchial tree, blood

vessels ,the alveolar septa,and interlobular setpa.

X-ray findings

Linear,reticular,or honeycombing.

Interstitial lung disease

Pleural effusion Etiology

TB,infection,thoracic trauma,heart failure

hypoproteinemia,malignancy.

Free pleural effusion

Localization of the effusion

Encapsulated effusion

Interlobar effusion

Infrapulmonary effusion

X-ray examiantion

can disclose the presence of pleural effusion,

but can not differentiate its nature.

Free pleural effusion

Small effusion

Cost-diaphragmatic angle is blunting (>300ml).

Moderate effusion

Cost-diaphragmatic angle completely disappear

Upper surface being curved,outer side is high,

inner is low.

Large effusion

• Upper border is over inferior margin of the

anterior second rib.

• Displacement of the trachea, mediastinum

and heart to the healthy side.

• Increasing intercostal spaces and depression

of the diaphram.

mild moderate severe

Pleural changes

Encapsulated effusion

Adhesion of visceral and parietal pleura may

cause localization of the effusion.

X-ray

Spindle-shaped homogeneous density.

Encapsulated effusion

Interlobar effusion

Pneumothorax & Hydropneumothorax

Air or fluid collected in the pleural cavity

X-ray findings

a. The radiolucent area has no pulmonary markings.

b. Inner side shows the visceral pleural line.

c. In large pneumothorax, the affected lung retracts toward the hilum.

d. Displacement of the mediastinum to healthy side.

e. Widening of intercostal spaces and depression of the diaphragm.

f. Hydrophneumothorax.

Fluid level presents horizontal level.

Air

Fluid

Compressed lung

Air

Pleural thicken, Adhesion, Calcification

Accumulation of fibrinous exudate and granulation.

Pleural thickening is always accompanied by pleural adhesion.

Commonly seen at costophrenic angle.

X-ray findings

Pleural thicken,Adhesion

Obliteration of the costophrenic angle.

Massive pleural thickening

Uniform,band-like density along the inner surface of the thoracic wall.

Pleural calcification

patchy,irregular,stippled or streaky

calcified shadow.

A. Right middle lobe atelectasis

B. Right middle lobe pneumonia

C. Anterior mediastinal lymphoma

D. Right pleural effusion

SELF-ASSESSMENT QUESTIONS

1. What is the most likely diagnosis?

.

2. PA chest radiograph of an 18-year-old man with cystic fibrosis shows a large

right hydropneumothorax and severe bilateral cystic bronchiectasis. What is the

most likely diagnosis?

SELF-ASSESSMENT QUESTIONS

A. Atelectasis

B. Pneumonia

C. Anterior mediastinal lymphoma

D. Primary spontaneous pneumothorax

What is the most likely diagnosis?

A. Left pleural effusion

B. Left lung collapse

C. Right pneumothorax

D. Left pneumonectomy

SELF-ASSESSMENT QUESTIONS

Diagnosis of Common Disease Diagnosis of Common Disease

Bronchiectasis

Chronic irreversible dilatation of diseased bronchi.Chronic irreversible dilatation of diseased bronchi.

CausesCauses

•• Postinfectious:bateria,viruses,etcPostinfectious:bateria,viruses,etc..

•• Mechanical Mechanical obstruction:foreignobstruction:foreign body,mucoidbody,mucoid

impaction,tumour,inflammatoryimpaction,tumour,inflammatory stenosis.stenosis.

•• CongenitalCongenital

•• ImmunodeficiencyImmunodeficiency

•• Granulomas and fibrosisGranulomas and fibrosis

•• IdiopathicIdiopathic

Bronchiectasis

Classical features

• Production of large volumes of purulent sputum

• Recurrent haemoptysis

• Frequent infective exacerbation

Bronchiectasis

Clssification

• Cylindrical bronchiectasis

• Varicose bronchiectasis

• Cystic bronchiectasis

Bronchiectasis

XX--ray findingsray findings

Plain filmPlain film Increasing and thickening of lung markings.Increasing and thickening of lung markings.

CTCT Cylindrical,varicoseCylindrical,varicose, or cystic appearance., or cystic appearance.

Bronchiectasis

Bronchiectasis

Bronchiectasis

shows dilated bronchi and bronchioles, forming a “cluster of grapes”

Pneumonia

Classification

Lobar pneumonia

Bronchopneumonia—Lobular pneumonia

Interstitial pneumonia

Lobar pneumonia Bronchopneumonia Interstitial pneumonia

Lobar pneumonia

• This has become less common since the advent of penicillin.

Causes

• Streptococcus pneumonia,

• Klebsiella pneumonia

• Legionella pneumonia

• Mycoplasma pneumonia

Lobar pneumonia

Clinical manifestation

• Abrupt onset high fever

• shaking chill

• cough

• purulent sputum, or rusty sputum

Lobar pneumonia

X-ray findings

• The typical radiological pattern—

Air-space consolidation involving an entire lobe

• Air bronchograms

Lobar pneumonia

• It may occur in previously normal lungs or be superimposed

on underlying bronchitis or other respiratory diseae,e.g.

bronchiectasis or carcinoma.

• It is preceded by bronchial infection and is commonest in

children and the elderly.

• In normal adults it may follow respiratory viral infections.

BronchopneumoniaBronchopneumonia

Causes

• Staphylococcus aureus

• Gram-negativeorganisms such as

Pseudomonas aeruginosa

BronchopneumoniaBronchopneumonia

Clinical manifestations

• History of acute bronchitis

• Commonly seen in children and eldly people

• Fever

• Productive cough,

• Infected (yellow or green) sputum.

• Corse crepitations

• Dullness to percussion

• Bronchial breathing

BronchopneumoniaBronchopneumonia

Pathological changes

• Lobular consolidation

• Edema and thickening of walls of the smaller bronchioles.

• The distribution of the lesions is usually lobular.

X-ray findings

• A scattered appearance of heterogeneous opacities

• A homogeneous opacification

• Atelectasis

BronchopneumoniaBronchopneumonia

Bronchopneumonia

Bronchopneumonia

Lung abscess

-- Focal areas of necrosis

caused by various suppurative inflammation, then develops lung abscess

Pathways

• Aspirated

• Haematogenous

• Infective

Clinical manifestations

Fever,shaking chill,pulurent sputum.

Lung abscess

Early stage

Exudative and consolidative shadow.

Acute stage

Abscess cavity with fluid level;

The wall thick and irregular.

Chronic stage

Thick and well-defined wall;

The cavity with or without fluid level.

a b c

Lung abscessLung abscess

Pulmonary tuberculosis

• Infection with the acid alcohol fast bacillus (AAFB) of

Mycobacterium tuberculosis affects predominantly the lungs, lumph

nodes and gut.

• Some features of the disease vary with the patient’s sensitivity to

tuberculin.

Pulmonary tuberculosis

Classification

Type I Primary pulmonary TB

Type II Haematogeneous pulmonary TB

Type III Secondary pulmonary TB

Type IV Tuberculous pleurisy

Type V Other

Primary pulmonary TB (Type I)

This is the syndrome produced by infection with M.tuberculosis in nonsensitive patients,i.e.in those who have not previously been infected.

Pathology

• Primary focus

• Lymphangitis

• Lymphadenitis

X-ray Findings

• Homogeneous air-space consolidation

• Ipsilateral hilar lymphadenopathy

• Pleural effusion

• Primary complex

Primary tuberculosis.

PA chest radiograph shows diffuse nodular airspace disease

Primary Complex

• Following infection,with the onset of tuberculin

sensitivity,the tissue reaction changes at both the focus and

in the nodes,to the characteristic caseating granuloma.

• The combination of a focus with regional lymph node

involvement is called the primary complex.

Primary tuberculosis. A: PA chest radiograph of a 71-year-old man with fever,

hemoptysis, and weight loss shows bilateral patchy airspace opacities, with areas of

cavitation in the upper lobes (arrows). Sputum contained numerous M.

tuberculosis organisms. B: PA chest radiograph taken 9 months later shows changes

of healing in upper lobes consisting of linear opacities (straight arrow) and thin-walled

cavities (curved arrows).

Intrathoracic lymph node TB

Lymph node enlargement may occur in the absence of a

radiographically visible parenchymal opacification.

Primary focus is easily resorbed.

Primary tuberculosis. CT shows low-density paratracheal

lymphadenopathy.

Hematogenous disseminated TB

(Type II)

Two types

• Acute miliary TB

• Subacute or chronic disseminated TB

Acute miliary TB

X-ray Findings

Clasical features --

• Diffused distribution

• Same size (1-2mm in diameter)

• Same density

Acute miliary TB

shows diffuse small nodules in the right lung, and cavitary disease on the left

associated with volume los

Subacute or chronic disseminated TB

X-ray findings

Heterogeneity of size,density and distribution.

Subacute or chronic disseminated TB

Secondary pulmonary TB(Type III)

X-ray findings

• Mostly seen in apical region,clavicular area and apical segment of the

lower lobes.

• Heterogeneous lesions

(exudation,consolidation,proliferation,dissemination,cavity,etc.)

unilateral or bilateral,scattered distribution,somewhat nodular

shape and indistinct margination.

• Reticulonodular opacities and associated volume loss.

• A “scarred” appearance in the upper lobe does not necessarily

mean inactivity.

• Tuberculomas.

Secondary pulmonary TB(Type III)Secondary pulmonary TB(Type III)

A: PA chest radiograph of a 28-year-old man with a prior history of right middle and lower lobectomy and

right pleurodesis, currently taking steroids for severe asthma, shows right apical opacity and a thin-walled

cyst (arrow) in the right upper lung. Both were new findings compared with prior chest radiographs. B: CT

shows the cyst and surrounding ill-defined nodules in the posterior right upper lobe.

Secondary pulmonary TB(Type III)Secondary pulmonary TB(Type III)

Tuberculomas

• Caseous lesion encapsulated by connective tissue.

• Round,solitary nodules;

• Commonly in the apical regions;

• Associated “satelite” foci.

CaseousCaseous pneumoniapneumonia

Chronic fibroChronic fibro--cavitarycavitary

pulmonary tuberculosispulmonary tuberculosis

Tuberculous pleurisy (Type IV)

a. Dry pleurisy

Pleura becomes thickened and rough.

b. Exudative pleurisy

Unilateral pleurisy is common

Manifestated as pleural effusion.

Tumor

Cassification

Primary and secondary

Malignant and benign

Lung cancer

Histology

• Squamous cell carcinoma

• Adenocarcinoma

• Small cell carcinoma

• Large cell undifferentiated carcinoma

Lung cancer

Classification by position

• Central tumor

• Peripheral tumor

• Bronchioalveolar cell carcinoma

X-ray Findings

Central tumours

• Obstructive emphysema

• Obstructive pneumonitis

• Obstructive atelectasis

PA (A) and lateral (B) chest radiographs of a 46-year-old woman with symptoms of

pneumonia show a mass in the left upper lobe. C: CT shows a 7.8-cm mass (T3)

arising from the left upper lobe bronchus (arrow). The patient underwent left

pneumonectomy. All nodes were negative.

Central tumor

A: PA chest radiograph of a 48-year-old man shows an irregular mass in the right upper

lobe abutting the mediastinum. B: CT shows the mass extending into the mediastinum.

The center of the mass is of low attenuation, secondary to tumor necrosis. C: CT at a

level inferior to (B) shows tumor along the posterior wall of the right upper lobe

bronchus. D: CT with lung windowing shows the spiculated mass and a background of

paraseptal and centrilobular emphysema.

Central tumor

A: PA chest radiograph of a 63-year-old

man with hemoptysis, cough, and dyspnea

on exertion shows collapse of the right lung.

The right main bronchus appears to be cut

off (arrow). The right hemithorax is opaque

and the mediastinum is shifted to the

right. B: CT shows a mass that almost

completely obliterates the lumen of the right

main bronchus (arrow). The large, low-

attenuation mass extends out into the right

lung. C: CT at a level inferior to (B) shows

anterior compression of the left atrium (LA)

by the mass. D: CT at a level inferior

to (C) shows tumor obliteration of the right

inferior pulmonary vein (solid arrow). Note

the normal left inferior pulmonary vein

(dashed arrow). The appearance of a

central tumor with postobstructive

pneumonia and atelectasis secondary to

total or partial bronchial obstruction is

typical of squamous cell carcinoma.

Central tumor

X-ray Findings

Peripheral tumours

• Ball-like lesions

• Homogeneous density

• Hazy margin,lobulation,spina,indentation

PA chest radiograph of a 72-year-old man with a 53 pack-year history of cigarette

smoking shows a mass in the right upper lobe.

CT shows a spiculated mass and a background of centrilobular emphysema.

Peripheral tumour

Bronchogenic adenocarcinoma.

CT scan shows a lobulated, spiculated

nodule in the right upper lobe (arrow).

Peripheral tumour

PA chest radiograph of a 45-year-old cigarette smoker with a cough for 3 months

shows an approximately 3-cm nodule in the left upper lobe (arrows), which was new

compared with prior chest radiographs.

CT scan shows that the nodule is slightly lobulated but fairly well circumscribed. The

tail sign is present (arrow); this is a nonspecific feature of peripherally located

pulmonary lesions that does not distinguish a benign from a malignant lesion.

Large-cell lung cancer.

X-ray Findings

Bronchioalveolar cell carcinoma

• A solitary pulmonary nodule with ill-defined and hazy contours.On CT,the

nodule frequently contains an air bronchogra,or small bubble-like lucences.

• Lobar consolidation mimicking pneumonia

• Multiple nodules scattered throughout both lungs

Metastatic pulmonary tumors

Pathways

Haematogenous

Lymphatic

Direct extension

Metastatic pulmonary tumors

Sources

The breast,colon,kidney,uterus,prostate, head and neck.

Choriocarcinoma,osteosarcoma,Ewing’s sarcoma,

testicular tumours,melanoma and thyroid carcinoma.

Metastatic pulmonary tumors

X-ray findigs

One or more nodules predominantly distributed in the

periphery of the lungs.

Usually well-defined outlines

Lymphangeitis -- beading changes

show numerous bilateral well-circumscribed pulmonary nodules of varying sizes,

typical of pulmonary metastases. Testicular carcinoma has a high incidence of

pulmonary metastases. Note on the PA view that some of the nodules are “hiding”

under the diaphragm (arrows) in the posterior lung bases. It is important to always

look carefully in this area for nodules, as they are more difficult to see when they are

not contrasted with the lucency of the air-filled anterior lung.

Trauma

man involved in a motor vehicle crash shows multiple right rib fractures creating a “flail

chest,” pleural opacification consistent with hemothorax, opacification of the right lung

from parenchymal injury, and numerous collections of air within the soft tissues of the

right chest wall

Anterior mediastinum

• Thymoma and thymic cyst

• Thyroid mass

• Germ cell neoplasm

Middle mediastinum

• Bronchogenic cyst

• Malignant lymphoma

Posterior mediastinum

• Neurogenic neoplasm

Mediastinal tumor

Thymoma (thymus tumor)

• Arising from thymic epithelium.

• It is the most common cause of a thymic mass.

• The majority are benign lesions confined within a fibrous capsule.

• About 30% them may be more aggressive.

• Usually occur between the ages of 40 and 60 years old, in males or females

equally.

Thymoma (thymus tumor)

• Mass located in the anterior mediastinum.

• Benign thymomas: a round or oval mass, well-defined.

• Intratumoral calcifications are present in 20-30%.

• Maliganant thymomas appear as irregular masses.

Dermoid or teratoma

• Arises from germ cells.

• Almost all of them originate in the anterior mediastinum.

• The majority of germ cell neoplasms are benign including mostly

mediastinal teratoma and dermoid cysts.

• Benign teratomas contain elements of the three germinal

layer.

• Dermoid cysts contain only ectodermal layer elements.

Dermoid or teratoma

• Round or oval masses found in this situation.

• Heterogeneous density with well-defined margins.

• Fatty and cystic components are present in about

half of the cases.

• Curvilinear,spherical or irregular calcifications.

• Identification of a tooth,while rare,is diagnostic.

Benign teratoma.

CT scan shows an anterior mediastinal mass of homogeneous soft tissue

attenuation (M), compressing a narrowed superior vena cava (solid arrow)

and right pulmonary artery (dashed arrow), and right pleural effusion (E).

Malignant lymphoma

Primary malignant neoplasm

of the lymphoreticular system,particularly of the

lymphocytes and histiocytes and the derivatives of these

two cell types.

• Hodgkin`s lymphoma

• Non-Hodgkin`s lymphoma

Hodgkin’s Disease

Retrosternal thyroid

• Usually a colloid or adenomatous goitre,and

occasionally a carcimoma.

• The great majority represent a downward

extension of a thyroid mass that originates in the neck.

• Most patients are asymptomatic.

• However,symptoms may arise from compression

of the trachea and esophagus.

Retrosternal thyroid

X-ray Findings

• Intrathoracic thyroid masses:

well-defined spherical or lobular outline.

• Displaceand narrow the trachea and esophagus.

• The key feature for the diagnosis is demonstration of

continuity of the mass with the cervical thyroid.

PA chest radiograph shows a widened upper mediastinum .

CT scan shows a thyroid heterogeneous mass.

Bronchogenic cyst

• Cyst arising from an abnormality in the primitive

foregut development.

• It is lined with respiratory epithelium and contains

mucoid material.

• Most cysts arise in the mediastinum or hila.

• The middle mediastinum is the most common

site,adjacent to the major airways.

• Most cases are asympomatic,and discovered

incidentally.

Bronchogenic cyst

X-ray Findigs

• Smooth,sharply marginated mediastinal masses.

• On CT, round or oval homogeneous masses with well-defined margins.

• Half of them show an attenuation similar to that of water

and the remainder appear of soft tissue attenuation.

• On MRI, well-defined margins without any perceptible walls.

Frequently show a signal intensity higher than that of

muscle on T1WI and very bright on T2WI.

Bronchogenic cyst

PA (A) and lateral (B)

chest radiographs of a

23-year-old man show

a round left parahilar

mass (arrows).

C: CT scan shows

that the nonenhancing

left hilar mass is of

homogeneous fluid

attenuation, consistent

with a cyst (C).

Neurogenic neoplasm

The most common cause of a posterior mediastinal

mass,mainly in a paraspinal location.

Pathologically divided into three main groups:

a. Nerve sheath neoplasms

b. Ganglion cell neoplasms

c. Paraganglionic cell neoplasms

(Paragangliomas)

Neurogenic neoplasm

• A sharply circumscribed homogeneous mass.

• Rib erosion with a sclerotic border is suggestive of a benign lesion.

• Calcification may be present in all types of neurogenic neoplasm.

• On CT,homogeneous soft tissue density.

• On MRI,well-defined masses of homogeneous signal intensity.

• Relationships with vertebrae,ribs and the spinal canal.

Thanks for your attention!Thanks for your attention!