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Fifth stage 

Radiology 

Lec-1

 

 

  زهراء

9/3/2016

 

 

Mediastinum and Heart 

 

Mediastinum 

mediastinum is a space in the thorax that contains a group of non-delineated organs and 
their surrounding connective tissue. It lies in the midline of the chestbetween the pleural 
surfaces 
of each lung and extends from the sternum to the vertebral column.

    

The mediastinum contains all the thoracic viscera except the lungs: heart and 
great vessels,
 oesophagus, trachea, phrenic nerve, cardiac nerve, thoracic 
duct,
 thymus, and mediastinal lymph nodes. 

Anatomical division 

The mediastinum can be divided into parts based on their relationship to thepericardium: 

1.  superior mediastinum: is an artificially divided compartment of 

the mediastinumlocated between the thoracic plane inferiorly and the thoracic 
inlet 
superiorly  

2.  anterior mediastinum: anterior to the pericardium 

3.  middle mediastinum: within the pericardium 

4.  posterior mediastinum: posterior to the pericardium  

Relations 

1.  superiorly: continuous with the loose connective tissue of the neck 
2.  anteriorly: chest wall 
3.  laterally: lungs and pleura 
4.  posteriorly: thoracic spine 
5.  inferiorly: diaphragm 

 

 

 

 

 

 


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Mediastinal lesion 

The differential diagnosis for an anterior mediastinal mass includes: 

1.  thymus 

a.  thymoma: most common primary neoplasm of the antero superior 

mediastinum 

b.  thymic cyst 

2.  thyroid and parathyroid 

a.  thyroid neoplasms 
b.  thyroid goitre 
c.  parathyroid neoplasms 

3.  lymphoma 

a.  Hodgkin lymphoma  
b.  non-Hodgkin lymphoma (NHL) 

4.  germ cell tumours 
5.  mediastinal teratoma 
6.  teratocarcinoma (malignant teratoma) 

 

Normal thymus gland   ( sail shape sign ) 

 


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Retro sternal goiter 

Radiographic features 

Chest radiograph 

It may show a superior mediastinal radio-opacity causing the deviation of trachea to 
opposite site. The superior

 

margin of the radio-opacity/mass is untraceable (cervicothoracic 

sign)

 

 

Middle mediastinum 

Related Pathology 

1.  malignancy 
2.  lymphadenopathy 
3.  hiatus hernia 
4.  thoracic aortic aneurysm 
5.  thyroid mass 
6.  bronchogenic cysts 

 

 

 


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Lymph adeno pathy 

The spectrum of conditions than can result in mediastinal lymph adenopathy is exhaustive 
and includes: 

1.  primary lung lung cancer 
2.  metastatic malignancies to the mediastinum from other sites common 

a.  oesophageal cancers 
b.  breast cancers 
c.  thyroid cancers 

3.  mediastinal lymphoma 

primary mediastinal large B-cell lymphom 

4.  Sarcoidosis 
5.  infective (acute suppurative) 
6.  reactive 

a.  follicular hyperplasia 
b.  granulomatous TB  , fungal infection 
c.  neoplastic 
d.  drugs: e.g. cyclosporin, phenytoin, methotrexate 

 

 

Lymphoma  
is a malignancy arising from lymphocytes or lymphoblasts. Lymphoma can be 
restricted to the lymphatic system or can arise as extra nodal disease. This, along 
with variable aggressiveness results in a diverse imaging appearance. 

 

Nodal disease 
Hodgkin's disease is usually almost entirely confined to the lymph nodes.  

 

Extra nodal disease  
Extra nodal HD although uncommon may be found in any organ system, either as a 
primary manifestation or as dissemination of systemic disease. 
 
 


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Hodgkin lymphoma of te middle mediastinum 

 

 

The differential diagnosis for      a posterior mediastinal mass includes: 

1.  neoplasm 

a)  neurogenic tumours  most common nerve sheath tumours 
b)  schwannoma 
c)  neurofibromaa 
d)  non-neurogenic tumours 
e)  oesophageal neoplasm 
f)  lymphoma 

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g)  metastasis 

2.  infection : paraspinal abscess 

3.  inflammation 


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a)  mediastinitis 

b)  sarcoidosis 

c)  lymphoid hyperplasia 

d)  pancreas pseudocyst 

4.  vascular : descending aortic aneurysm 
5.  hernias  

a)  hiatus hernia 
b)  Bochdalek hernia 

6.  trauma  
7.  paraspinal hematoma 
8.  lymphadenopathy 
9.  extramedullary haematopoiesis 
10. foregut duplication cysts 
11. neurenteric cyst 
12.  oesophageal duplication cyst  

Heart   

Assessment & measurement

  

The heart has a somewhat conical form and is enclosed by pericardium. It is positioned 
posteriorly to the body of the sternum with one-third of it is  situated on the right and two-
thirds on the left of the midline . 

The heart has four borders: 

1)  right border: IVC, right atrium, SVC 
2)  left border: left ventricle, left atrium, pulmonary trunk and arch of aorta 
3)  inferior border: right ventricle 
4)  superior border: right and left atria, SVC, ascending aorta and pulmonary trunk  

Cardiothoracic ratio (CTR) = Cardiac Width : Thoracic Width 

A CTR of greater than 1:2 (50%) is considered abnormal. This however, assumes the 
projection is Posterior-Anterior (PA), and that cardiac size is not exaggerated by factors 
such as patient rotation or an incomplete breath in . 

The cardiothoracic ratio aids in the detection of cardiomegaly, or more 
broadly,enlargement of the cardiac silhouette.  

 

 

 


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Enlargement of the cardiac silhouette on chest x-ray can be due to a number of causes : 

1.  cardiomegaly (most common cause by far) 
2.  pericardial effusion 
3.  anterior mediastinal mass 
4.  prominent epicardial fat pad 

Causes of cardiomegaly 
There are many aetiologies for cardiomegaly. The list includes: 

1.  Mitral valve disease  
2.  Congestive heart failure  
3.  Congenital heart disease  

a.  -tetralogy of Fallot 
b.  -Ebstein anomaly 

Mitral valve disease 

Radiographic features 

Plain film 

Typical radiographic features of mitral regurgitation include : 

frontal projection 

1.  left atrial enlargement 

convexity or straightening of the left atrial appendage just below the main 
pulmonary artery (along left heart border) 

2.  double density sign: the right side of the enlarged left atrium pushes into the 

adjacent lung and creates an addition contour superimposed over the right heart 

3.  elevation of the left main bronchus and splaying of the carina 
4.  upper zone venous enlargement due to pulmonary venous hypertension 
5.  left ventricular enlargement is also eventually present due to volume overload 
6.  Features of pulmonary oedema may also be present. 


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Congestive cardiac failure (CCF) 

is a form of cardiac failure which is primarily 

manifested by the heart inability to pump the volume of blood. It can affect the left 
(common) or right cardiac chambers or both. 

Radiographic features 

Chest radiograph   

With left sided congestive cardiac failure, the features are that of pulmonary edema which 
includes: 

1.  central pulmonary venous congestion ( prominent hilum ) 
2.  cephalisation of pulmonary veins ( upper lobe pulmonary venous diversion ) 
3.  pulmonary interstitial oedema 
4.  pulmonary alveolar oedema 
5.  Cardiomegaly 
6.  Pleural effusion   

 

Pulmonary edema

 is a broad descriptive term and is usually defined as an abnormal 

accumulation of fluid in the extra-vascular compartments of the lung . 

Radiographic features 

Septal lines, also known as Kerley lines, are seen when the interlobular septa in the 
pulmonary interstitium become prominent. This may be because of lymphatic engorgement 
or edema of the connective tissues of the interlobular septa. They usually occur when 
pulmonary capillary wedge pressures reach 20-25 mmHg , 

 

 


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Classification 

1.  Kerley A lines 

These are 2-6 cm long oblique lines that are      <1 mm thick and course towards 
the hila. They represent thickening of the interlobular septa  

2.  Kerley B lines 

These are 1-2 cm thin lines in the peripheries of the lung. They are perpendicular 
to  and extend out to the pleural surface . They represent thickened sub pleural 
interlobular septa and are usually seen at the lung bases.  

 

Interstitial pulmonary edema 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


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radiograph include if pressure > 25 mmHg the findings of : 

1.  cardiac size/cardio-thoracic ratio: useful for assessing for an underlying 

cardiogenic cause or association 

2.  bat wing pulmonary opacities 
3.  presence of peri-bronchial cuffing 
4.  septal lines: Kerley lines become more prominent  
5.  pleural effusions 
6.  pulmonary venous engorgement/pulmonary blood flow distributionupper lobe 

pulmonary venous diversion 

 

Alveolar pulmonary edema 


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Pericardial effusions

 occur when fluid collects in the pericardial space (a normal 

pericardial sac contains approximately 30-50 mL of fluid). 

Radiographic features 

Plain radiograph 

a very small pericardial effusion can be occult on plain film 

there can be globular enlargement of the cardiac  shadow giving a water bottle 
configuration 
known as Globe shape heart or pumpkin shape heart   . 

 

  

 

 

 

 

 

 

 

 

 

 


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Congenital heart disease 

A . CCHD 

A number of entities can present as cyanotic congenital heart disease. These can be divided 
into those with increased or decreased pulmonary vascularity. They include: 

1)  increased pulmonary vascularity 

a)  total anomalous pulmonary venous return (TAPVR) (types I and II
b)  transposition of the great arteries (TGA) 
c)  truncus arteriosus (types I, II and III) 
d)  large AVSD 
e)  single ventricle without pulmonary stenosis 

2)  decreased pulmonary vascularity 

a)  tetralogy of Fallot  
b)  pentalogy of Cantrell 
c)  many other combined and infrequent anomalies such as 
d)  Ebstein anomaly with atrial septal defect 

B . ACCHD 

There are numerous causes of acyanotic congenital heart disease and can be divided into 
those that have increased pulmonary vascularity and those that do not. They include: 

1)  increased pulmonary vascularity 

a)  ventricular septal defect (VSD) 
b)  atrial septal defect (ASD) 
c)  atrioventricular septal defect (AVSD) 
d)  patent ductus arteriosus (PDA) 

2)  normal pulmonary vascularity 

a)  small shunts (see above) 
b)  aortic valve stenosis 
c)  aortic coarctation 
d)  pulmonary stenosis 

 

Tetralogy of Fallot (TOF)

 is one of the most common cyanotic congenital heart 

conditions and continues to be a major source of morbidity . 

Tetralogy of Fallot is classically characterised by four features which are: 

1)  ventricular septal defect (VSD) 

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2)  right ventricular outflow tract obstruction (RVOTO) due to:pulmonary artery 

stenosis 

3)  overriding aorta 


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4)  right ventricular hypertrophy 

 

Radiographic features 

Plain film 

Plain films may classically show : 

1)  "boot shaped" heart with an upturned cardiac apex due to right ventricular 

hypertrophy and concave pulmonary arterial segment.  

2)  Pulmonary oligaemia due to decreased pulmonary arterial flow.  
3)  Right sided aortic arch is seen in 25%. 

"boot shaped" heart ( TOF ) 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


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Transposition of the great arteries (TGA) 

is the most common cyanotic congenital 

cardiac anomaly with cyanosis in first 24 hours of life. It accounts for up to 7% of all 
congenital cardiac anomalies 

 

Chest radiograph 

A frontal chest radiograph classically shows cardiomegaly with a cardiac contours classically 
described as appearing like an egg on a string . There is often an apparent narrowing of the 
superior mediastinum as result of the aortic and pulmonary arterial  configuration . 

 Egg-on-a-string sign ( TGA ) 

 

 

 

 

 

 

 

 

 

 

 

Ventricular septal defects (VSD) 

They represent one of the most common congenital 

cardiac anomalies and up to 40% associated with such anomalies .  They are considered the 
most common congenital cardiac abnormality diagnosed in children and the second most 
common diagnosed in adults

 

Ventricular septal defects (VSD)

 

represent defects in the inter ventricular septum that allow 

a hemodynamic communication between the right and left ventricles. It typically results in 
a left to right shunt.

 

 


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Radiographic features 

Plain film 

The chest radiograph can be normal with a small VSD. 

Larger VSDs may show 

1)  cardiomegaly (particularly left atrial enlargement although the right and left 

ventricle can also be enlarged).  

2)  A large VSD may also show features of pulmonary arterial hypertension. 
3)  pulmonary oedema  
4)  pleural effusion and/or increased pulmonary vascular markings.   

 

Pulmonary arterial hypertension

  

results from elevation of the resistance in the pulmonary arterial bed, usually at the 
arteriolar level. It is characterized radiographically by enlargement of the pulmonary trunk 
and right and left main pulmonary arteries with disproportionately small peripheral vessels 
This has been referred to as "pruning" of the pulmonary arteries   

So the Plain radiograph 

1)  elevated cardiac apex due to right ventricular hypertrophy 
2)  enlarged right atrium 
3)  prominent pulmonary outflow tract 
4)  enlarged pulmonary arteries 
5)  pruning of peripheral pulmonary vessels 

Pulmonary venous hyper tension 

Pulmonary venous hypertension (PVH) results from an increase in pressure in the 
pulmonary veins, usually as a result of left atrial hypertension. This is measured clinically as 
an increase in the pulmonary capillary wedge pressure (PCWP) over the normal 12 to 14 
mmHg. 

Mild elevation of the PCWP results in redistribution of the pulmonary blood flow to the 
non-dependent lung zones 

As the pressure approaches 20 mmHg, interstitial edema develops 

Common causes of PVH:  

1)  1.obstruction to LV inflow,  
2)  2.LV systolic dysfunction,  
3)  3.severe mitral regurgitation,  
4)  4.acute pulmonary and systemic volume overload.  


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Eisenmenger syndrome 

is a complication of an uncorrected high-flow, high-

pressure congenital heart anomaly leading chronic pulmonary arterial hypertension and 
shunt reversal

 . 

Important Complications of VSD  

Eisenmenger phenomenon with shunt reversal (i.e. L to R becomes R to L) 

Very important to consider 

1)  figure of 3 sign: contour abnormality of the aorta with  inferior rib notching 

: Roesler sign in Coarctation of the aorta 

2)  "box shape"  heart in Ebstein anomaly  
3)  boot shaped heart  ( TOF ) 
4)  Egg-on-a-string sign ( TGA ) 
5)  figure of 8 heart or cottage loaf heart in Total 

anomalous pulmonary venous return (TAPVR) 

 

 

"box shape"  heart in Ebstein anomaly 

 

 

 




رفعت المحاضرة من قبل: ابراهيم محمد فوزي الشهواني
المشاهدات: لقد قام 4 أعضاء و 95 زائراً بقراءة هذه المحاضرة








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