7. Mediastinal lines or stripes are interfaces between the soft tissue of
mediastinal structures and the lung, the aortopulmonary window is
the interface below the aorta and above the pulmonary trunk and is
concave or straight laterally
8. Anterior junction line results from the anterior apposition of the lungs, which lies behind the upper two-
thirds of the sternum, the line consists of four layers of pleura and a variable amount of
intervening fat, it appears as a thin oblique line projecting over the superior two-thirds of the
sternum and runs from the upper right to the lower left, it does not extend above the level of
clavicles, posterior junction line results from the apposition of the lungs posterior to the
esophagus and anterior to the 3rd to 5th thoracic vertebrae, similarly to anterior junction line, it is
formed by four layers of pleura, it appears as a thin straight line projecting through the trachea,
unlike anterior junction line, it can be seen above the clavicles
9. Mediastinal signs, frontal chest film (a) shows the hilum (arrow), which indicates
that the mass is either anterior or posterior to the hilum, this is the hilum
overlay sign in patient with lymphoma, frontal chest film (b) shows
enlargement of the right superior mediastinum, above the level of the
clavicles, the margins of the mass are sharp (arrow) due to the interface
with adjacent lung, indicating that the mass is located in the posterior
mediastinum
10. 1-Anterior Mediastinal Masses (5Ts)
a) Thymus Abnormalities
b) Thyroid Masses
c) Terrible Mediastinal Lymphoma
d) Germ Cell Tumors
e) Thoracic Aortic Aneurysm
f) Pericardial Cyst
g) Morgagni Hernia
h) Sternal Tumors
i) Pericardial Fat Pad
11. -The anterior mediastinum is that portion
of the mediastinum anterior to the
pericardium and below the level of
the clavicles
-It includes the thymus , lymph nodes and
may contain the portions of a retrosternal
thyroid
14. -On frontal chest radiographs in
infants and young children , the
thymus is strikingly large but
difficult to discriminate from the
cardiac silhouette
-The thymus usually has smooth
borders and remains visible on
radiographs through the age of 3
years
-The thymic wave sign , a scalloped
or wavy contour of the organ is
created by the impression of the
anterior reflection of the ribs
-The thymic sail sign , a triangular
slightly convex right lobe of the
thymus with a sharply demarcated
base caused by the minor fissure
15. -Typically , the thymus is
visible at CT and fills the
perivascular space
throughout the first 2
decades of life
-In children younger than 5
years , it typically appears
quadrilateral with convex
borders
-As children grow , the
thymus gradually
becomes triangular with
straight or concave
border
17. a) Incidence :
-Thymoma is the most common anterior
mediastinal tumor in the adult (very rare in
children)
18. b) Associations :
1-Myasthenia Gravis (35% of thymoma
patients have myasthenia gravis)
2-Aplastic Anemia (50% have thymoma)
3-Hypogammaglobulinemia
4-Red cell Aplasia
19. c) Pathology :
1-Benign Thymoma, 75% :
-Common in patients with myasthenia
2-Malignant Thymoma , 25% :
-Local spread into pleura but no
hematogenous metastases
-More common in patients without
myasthenia
21. 1-Plain Radiography :
-Presents as an anterior mediastinal mass
-Seen as a well defined lobulated soft tissue
density slightly towards one side of the
mediastinum
-Can demonstrate associated calcification
(commonly amorphous / flocculent)
22.
23.
24.
25.
26. 2-CT :
-Anterior mediastinal soft tissue mass :
1-Asymmetrical location on one side
2-Homogeneous density and signal intensity
3-Some have cystic components (40% of the cases and
are mostly focal)
4-Contrast medium enhancement
5-Invasive thymomas show growth through capsule into
adjacent tissue , drop metastases into pleural space are
common
6-Calcification , 20 %
27.
28.
29.
30.
31. CT shows anterior mediastinal masses with coarse calcifications (A) and a
circular peripheral calcification (B)
32. Cystic thymoma , CT+C shows a low attenuation lesion (arrow) in the anterior
mediastinum
34. Axial contrast-enhanced CT images showing a left anterior mediastinal
mass (arrows in a) associated with a left parietal pleural nodule
(arrow in b) and left diaphragmatic pleural nodules (arrows in c),
apperances are those of invasive thymoma with pleural «drop
metastases»
35. Thymoma with no signs of mediastinal fat invasion (A, arrows) , one year after
surgery , pleural metastasis was found (B, arrow)
37. a) Incidence :
-Is a rare benign anterior mediastinal
mass of thymic origin
-Comprises 2-9% of all thymic neoplasms
-Mean age of 22 years
-Tumors usually grow to large sizes (75%
are >500 g) with few or no symptoms
38. b) Associations :
1-Myasthenia Gravis (in 3 % of thymolipoma)
2-Aplastic Anemia
3-Hypogammaglobulinemia
4-Grave’s Disease
c) Pathology :
-Thymolipomas are composed of a mixture mature
adipose tissue with islands of thiymic tissue
40. 1-Plain Radiography :
-Typically these tumors appear as
large anterior mediastinal masses
-The larger tumors tend to hang down one
or either side of the pericardium and being
soft , they mold themselves to the
adjacent mediastinum and diaphragm and
often mimic cardiomegaly
41.
42. Thymolipoma : a) Chest radiograph showing a widening of the cardiac
silhouette , b) CT confirms the presence of a heterogeneous mass
with fatty components growing in caudal direction
43.
44. 2-CT :
-On CT thymolipomas typically appears
almost entirely fatty with some areas of
inhomogeneous soft tissue density that
represent thymic tissue
45.
46.
47. CT show a large and well defined mass (arrows) that has extensive fat content
and contains small amounts of thin fibrous septa
50. a) Pathology :
-It can be subdivided into two forms :
1-True Thymic Hyperplasia
2-Lymphoid Hyperplasia
51. b) Causes :
1-True Thymic Hyperplasia :
a) Rebound hyperplasia to chemotherapy ,
thymic rebound hyperplasia (3 to 10
months after the start of chemotherapy)
b) Radiation Therapy
c) Burns
d) Other Severe Systemic Stresses (e.g.
pneumonia)
52. 2-Lymphoid Hyperplasia :
a) Myaesthenia Gravis
b) SLE
c) Rheumatoid Arthritis
d) Scleroderma
e) Graves Disease
53. c) Radiographic Features :
-Diffuse symmetric enlargement of the gland is
the key morphologic feature of hyperplasia
(neoplasm tends to manifest as a focal mass)
-Size and morphology of normal thymus :
>20 years of age : <13 mm
>30 years of age : Convex margins are abnormal
-No increase in size over time
54. Thymic rebound hyperplasia in an 18 month old girl recovering from pneumonia
(a) Frontal chest radiograph shows air trapping and bilateral perihilar peribronchial infiltrates (arrows) ,
findings consistent with viral pneumonia
(b) Follow-up radiograph shows thymic rebound hyperplasia (arrowheads) and resolution of the
pneumonic infiltrates (arrows)
55. Thymic rebound hyperplasia in an 11 year old girl with Hodgkin lymphoma
(a) CTC shows right sided mediastinal adenopathy (arrow) , Arrowhead = thymus
(b) CT scan obtained after completion of chemotherapy shows regression of the
adenopathy (arrow) , there is early thymic rebound hyperplasia (arrowhead)
(c) CT scan obtained 1 month after chemotherapy shows that the nodal mass has almost
resolved (arrow) and the thymic rebound hyperplasia is nearly complete (arrowhead)
56. Dramatic thymic rebound hyperplasia in a 14 year old boy who
completed chemotherapy for primary mediastinal T-cell lymphoma 6
months earlier
60. a) Causes :
1-Congenital :
-Contains thymic tissue in wall : often unilocular
2-Acquired : often multilocular
a) Secondary to thoracotomy
b) Following chemotherapy or radiotherapy for
mediastinal malignancy
c) Inflammatory
64. 2-CT :
-Thin walls and no solid component and
show no contrast enhancement
65. CT+C shows inhomogenous unilocular low attenuation mass (arrows)
in the anterior mediastinum
66. A well marginated mass with a homogeneous attenuation usually in the
range of water attenuation (0–20 HU) and without an enhancement
of the wall or infiltrative appearance
67. Cystic changes of the thymus and lymph nodes at diagnosis in a 19
year old man with Hodgkin lymphoma , CT+C shows a solid (arrow
in a) and cystic (arrows in b) thymic mass , by the time the patient
completed chemotherapy , the cystic nodes had resolved but the
cystic areas in the thymus remained unchanged
68. Cystic change of the thymus in a 28 year old man with Hodgkin
lymphoma treated 3 years earlier , CT+C shows a thymic cyst
(arrow) and thymic rebound hyperplasia (arrowhead)
74. CXR of a partial substernal goiter compressing the trachea from the right side
75.
76.
77.
78. b) CT :
-Mass is contiguous with cervical thyroid and is
well defined
-Heterogeneous density by CT : calcium , iodine
(70 to 120 HU) , colloid cysts
-Marked and prolonged contrast enhancement
-They don’t usually project below the arch of the
aorta (differentiating them from thymomas and
teratoma)
-Nuclear scan with either 99mTc or 123I confirms
the diagnosis
79. Frontal (a) view of the chest radiograph shows an opacity on the right side of
the trachea (arrow), which appears shifted contralaterally and reduced in
caliber, unenhanced CT scans (b-d) demostrate a heterogenous mass
which goes down into the anterior mediastinum referred to a goiter
80. Substernal Thyroid Goiter , CT+C of the chest shows a large contrast
enhancing mass in the anterior mediastinal containing calcifications
and areas of necrosis
81. CT of a partial substernal goiter compressing the trachea from the left side
83. 1-Incidence :
-Lymphomas are responsible for 45%
of anterior mediastinal masses in children
-Only 10% of lymphomas which involve the
mediastinum are primary (i.e.
mediastinum involvement not part of
systemic disease) and the majority are
Hodgkin lymphomas (50-70%)
87. a) Plain Radiography :
-A soft tissue mass may be clearly visible or more
frequently the mediastinum is widened and
the retrosternal airspace is obscured
-The hilum overlay sign refers to an appearance on
frontal chest radiographs of patients with a mass
projected at the level of the hilum which is in fact either
anterior or posterior to the hilum , when a mass arises
from the hilum, the pulmonary vessels are in contact with
the mass and as such their silhouette is obliterated , the
ability to see the edges of the vessels through the mass
implies that the mass is not contacting the hilum and is
therefore either anterior or posterior to it , most of these
masses are found to be in the anterior mediastinum
94. b) CT :
-Soft tissue attenuating mass with smooth or
lobulated margins which conforms to
surrounding structures (prevascular ,
paratracheal) involvement
-Other features include :
1-Parenchymal invasion , uncommon
2-Pleural effusion
3-Pericardial effusion
4-Chest wall invasion
95. -Calcification is usually seen following
therapy and can have varying morphology
including irregular , diffuse or even egg
shell
-Lymphomas have areas of necrosis but
they usually do not have cystic areas ,
thymic cysts can occur after irradiation of
mediastinal lymphomas or chemotherapy
96. Large soft tissue mass in the anterior mediastinum which
arises in the thymus , there is associated paratracheal
adenopathy (arrow)
101. 28 year old woman with Hodgkin disease , chest radiograph shows an
anterior mediastinal mass (A, arrow) which on axial CT is irregular
and shows areas of necrosis (B, arrows)
107. 1-Incidence :
-Germ cell tumors are the most common
cause of a fat containing lesions in the
anterior mediastinum and the second
most common cause of an anterior
mediastinal mass in children
108. 2-Pathology :
-Tumors arise from rests of primitive cells and are
of variable malignant potential (SECTE)
a) Seminoma
b) Embryonal cell carcinoma
c) Choriocarcinoma
d) Teratoma (70% of germ cell tumors) ,
teratocarcinoma
e) Endodermal sinus tumors (yolk sac tumors)
114. Teratoma in a 39 year old man , PA chest film shows an anterior
mediastinal mass (A, arrows) , CT shows a large area of fat within
the mass (B, arrow)
115.
116. b) CT :
-Benign teratoma (90%) is a well defined thick wall
cystic mass containing a variable mixture of :
Calcification , 30%
Fat , fat-fluid levels
Cystic areas
Soft tissue
-Mature teratoma can be very large and still be
benign
-Malignant teratoma (10%) tends to have irregular
or nodular walls and a predominance of soft
tissue components , may show pulmonary or
liver metastases and chest wall invasion
117. Extensive mediastinal involvement (A,B, white arrows) , cystic upper
mediastinal mass (A,B red arrows) , immature tooth (B, yellow arrow)
118. 42 year old man with a teratoma , note the coarse calcifications (A,B,
white arrows) and areas of fat attenuation measuring -103 HU (A,B,
red arrows)
119. CT+C shows large septated anterior mediastinal mass
containing fat and bony elements
120. CT+C shows an anterior mediastinal mass containing calcification (black arrow)
, fat (white arrow) and soft tissue components (dotted white arrow)
131. a) Plain Radiography :
-The thoracic aorta can usually be seen on
both frontal and lateral chest radiographs
and aneurysms are often obvious
-Mural calcification is seen both in
atherosclerotic disease as well as various
causes of aortitis
132.
133.
134.
135. b) CT :
-CTA is the work horse of aneurysm assessment
-Typically aneurysms appear as dilatations of the
lumen , the walls may be thin or thickened by
presence of mural thrombus (circumferential or
more frequently eccentric)
-Calcified atherosclerotic disease is often identified
not only in the wall of the aneurysm but in
adjacent arteries
-If rupture or leak has occurred hematoma / fluid
may be seen adjacent to the aorta , in the left
pleural cavity or in the pericardium
140. 1-Incidence :
-Uncommon benign congenital anomaly of
the anterior mediastinum
-Incidental findings in asymptomatic patients
, usually after age 30
141. 2-Location :
-Found in the right anterior cardiophrenic
angle but can be found almost anywhere
adjacent to the heart
143. a) Plain Radiography :
-Well defined round or oval masses located
in the normally clear cardiophrenic angle
144.
145.
146.
147.
148. b) CT :
-Usually appears as a well defined non-
enhancing low (water) attenuating
rounded mass next to the pericardium
149.
150.
151.
152.
153.
154. Typical benign pericardial cyst with serous content in a 46-year-old
woman, (a) Coronal T1 shows a round low-signal-intensity cyst with
a regular thin wall, (b) T2 shows a homogeneous high-signal-
intensity cyst without septation or a mural nodule
155. 4-Differential Diagnosis : From cystic mediastinal mass :
1-Congenital :
a) Bronchogenic cyst , usually subcarinal or right
paratracheal site
b) Enteric cyst , paraoesophageal site
c) Neuroenteric cyst , associated anomaly of spine
2-Pericardial cyst , usually cardiophrenic angle
3-Thymic cyst , can develop following radiotherapy for
Hodgkin’s disease
4-Cystic tumors :
a) Lymphangioma
b) Teratoma
c) Teratodermoid
5-Pancreatic pseudocyst , can track up into mediastinum
6-Meningocele , 75% association with NF
7-Chronic abscess
8-Old hematoma
157. Morgagni hernia in a 2 year old child , lateral chest radiograph shows
herniation of a bowel loop (arrows) in a classic location through an
anteromedial defect
158.
159. h) Sternal Tumors :
-Metastases are the most common (breast ,
bronchus , kidney & thyroid)
-Malignant primary tumors (chondrosarcoma
, myeloma , reticulum cell sarcoma and
lymphoma) are more common than benign
(chondroma , Aneurysmal bone cyst and
Giant cell tumor)
160.
161.
162. i) Pericardial Fat Pad :
-Especially in obese people
-A triangular opacity in the cardiophrenic
angle on the PA view
-It appears less dense than expected
because of the fat content
163. Epicardial fat pad , (a) PA chest radiograph shows loss of the cardiac
silhouette at the border of the right side of the heart and an
epicardial fat pad with relatively low density (arrow) , (b) CT scan
shows the fat pad (arrow) as an area of homogeneous fat
attenuation adjacent to the right border of the heart
165. 2-Middle Mediastinal Masses : (A+B)
1-Adenopathy
2-Aortic Aneurysm
3-Bronchogenic Cyst
4-Carcinoma of the Bronchus
166. 1-Adenopathy :
-The paratracheal , bronchopulmonary and / or
subcarinal nodes may be enlarged
-This may be due to :
a) Neoplasm (Lymphoma , Leukemia & Mets)
b) Infection (most commonly T.B. , Histoplasmosis
or coccidiodomycosis)
c) Sarcoidosis
d) Hyperplasia (Castleman’s disease)
167. a) Neoplasm (Lymphoma , Leukemia & Mets) :
-See Lung neoplasms
b) Infection (most commonly T.B. ,
Histoplasmosis or coccidiodomycosis) :
-See Pulmonary Infections
c) Sarcoidosis :
-See Diffuse Lung Lesions
168.
169. PA chest radiograph shows the right paratracheal stripe (arrow) , the azygos vein is seen at the
inferior margin of the stripe at the tracheobronchial angle (arrowhead) , (b) CT shows the right
wall of the trachea with medial and lateral air soft tissue interfaces caused by air within the
tracheal lumen and right lung (arrow) , these interfaces create the right paratracheal stripe , note
the position of the SVC (arrowhead) which explains why the paratracheal stripe is seen projecting
through the SVC at radiography , (c) CT obtained at the level of the azygos arch shows that the
azygos vein (arrow) disrupts the lung tracheal wall interface at the tracheobronchial angle
170. Lymphadenopathy , (a) PA chest radiograph , the right paratracheal stripe is not
seen having been obliterated by a right paratracheal mass (arrowheads) ,
(b) CT shows right paratracheal lymphadenopathy (arrow) which obliterates
the air soft tissue interface between the right lung and the tracheal wall , this
finding explains the obliteration of the right paratracheal stripe in a
171. PA chest radiograph , the AP window reflection (arrowhead) extends from the aortic knob
to the left pulmonary artery and has a normal concave appearance , the aortic
pulmonary reflection (arrow) is a more anterior line and extends from the aortic arch
to the level of the left main bronchus
172. AP window lymphadenopathy , (a) Chest radiograph shows the AP
window with an abnormal convex border (arrow) , (b) CT shows
lymphadenopathy (arrow) which accounts for the distortion of the AP
window in a
174. Frontal Chest X-ray (a,b) shows a slightly convex border of the aortopulmonary
window (arrow) suspicious for the presence of a mass in the middle
mediastinum, CT scan shows enlarged lymphnodes in the aortopulmonary
window (arrow), causing the abnormality seen on chest radiography, it was
a lymphoma in a 11-year-old-girl
177. Frontal (a) and lateral (b) chest X-ray show a bilateral hilar enlargement, more
evident on the right, CT+C (c,d) showing bilateral hilar lymph nodes in
patient with sarcoidosis
181. 3-Radiographic Features :
-Bulky mediastinal mass lesion (3 to 12 cm) :
anterior > middle > posterior mediastinum
-Dense homogeneous contrast enhancement is
the key feature (vascular lesions)
-On CT, 5% to 10% of Castleman disease showed
intralesional calcifications, typically being
discrete in morphology
-Dynamic CT demonstrates early rapid
enhancement with washout in the delayed phase
182. PA chest Radiograph shows
widening of upper
mediastinum ,
aortopulmonary and
azygos adenopathy and
enlargement of hila
(arrows) with extension of
lesion below right hilum
183.
184. Unenhanced CT using bone window setting reveals posterior
mediastinal mass (arrow) with typical arborizing pattern of
intralesional calcifications
185. CT+C shows matted lymphadenopathy (arrows) formed by confluence
of inhomogeneously enhancing enlarged lymph nodes confined to
anterior mediastinum
188. Aneurysm of the aortic arch. (a) PA chest radiograph shows the AP window with a convex
border (arrow) , (b) CT reveals an aneurysm (arrow) arising laterally from the aortic
arch , a finding that accounts for the abnormality seen in a
191. (a) PA chest radiograph demonstrates a subcarinal abnormality with increased
opacity (*) , splaying of the carina and abnormal convexity of the upper and
middle thirds of the azygoesophageal line (arrowheads) , (b) Corresponding
CT scan helps confirm a subcarinal mass (arrow) which proved to be a
bronchogenic cyst
192.
193. CT+C : well circumscribed unilocular water attenuation cyst in the
middle mediastinum , the cyst has smooth imperceptible walls with
no enhancement
195. CT Scanogram (a) shows an oval, huge, mass (arrows) that cause a widening
and distortion of azygoesophageal recess, coronal (b) and sagittal (c) MPR
reconstruction demonstrate a cyst with uniform water attenuation and with
an imperceptible wall, this was a bronchogenic cyst
196. Bronchogenic cyst in a 49-year-old man with a 2-week history of fever and
cough, (a) Chest radiograph shows a round mass (arrow) that displaces the
right primary bronchus superiorly, as well as pneumonia of the middle lobe
and pleural effusion, (b) Contrast material-enhanced CT scan shows a cyst
with uniform water attenuation and with an imperceptible wall.
197. Bronchogenic cyst in a 44-year-old woman with a 3-year history of
chest pain, CT scan shows a thin-walled water-attenuation cyst in
the posterior mediastinum (arrow)
202. a) A 55 yr old dyspnoeic
female , chest radiograph
shows widened
mediastinum particularly
on the right with reduced
vascularity of the right
lung
b) CT+C shows central
mediastinal mass
invading the right
pulmonary artery , small
cell carcinoma was
confirmed on
percutaneous biopsy
204. 1-Posterior Mediastinal Neural Tumors :
a) Incidence
b) Peripheral Nerve Sheath Tumor
c) Sympathetic Ganglia Tumors
d) Paraganglioma
205. a) Incidence :
-Neurogenic tumors are the cause of
approximately 90% of posterior mediastinal
masses
-They can be subdivided into three groups by their
location and involvement of peripheral nerves or
sympathetic chain :
1-Peripheral Nerve Sheath Tumors
2-Sympathetic Ganglia Tumors
3-Paraganglioma
-Peripheral nerve sheath tumors and
paragangliomas are far more common in
adults while the sympathetic ganglia tumors
are commoner in children
207. 1-Incidence :
-These tumors manifest as round paravertebral
masses that span one or two vertebral bodies
-They are homogenous soft tissue attenuation
masses at CT and the commonest cause of
posterior mediastinal and paravertebral masses
-They may cause widening of the neural foramen
and thickening of the adjacent posterior rib
211. a) Incidence :
-Are benign tumors of schwann cell origin
and are the most common tumor of
peripheral nerves
-Peak presentation is in the 5th-6th decades
-When they occur in patients with
neurofibromatosis type 2 (NF2)
schwannomas usually present by the 3rd
decade
216. 1-Plain Radiography :
-Both benign and malignant tumors may erode ribs
-They may enlarge the neural foramina (dumbbell
shaped lesion)
-Scalloping of posterior vertebral bodies may occur
-They may produce a scoliosis
-Pleural effusion may occur with benign as well
as malignant neural tumor
217. There is an opacity in the left posterior mediastinum , there is associated
widening of the 4th intercostal space posteriorly with scalloping of the
inferior margin of the 4th rib , there is also some coarse calcification within
the lesion
218.
219.
220.
221. Cervical X-Ray (a-b) demonstrate a marginated and round opacity
(white arrows), with disrupting of left paravertebral stripe, CT scan
(c) confirms a left hypodense and homogeneous paravertebral
mass, this mass revealed features consistent with schwannoma
222. 2-CT :
-Isodense round or oval mass , <2 vertebral
bodies long
-Dense contrast enhancement :
Small tumors show homogeneous
enhancement
Larger tumors may show heterogeneous
enhancement
228. 3-MRI :
*T1 : 70% hypointense , 30% isointense
*T2 : Very hyperintense , may show small
internal low signal foci (calcification) and
areas of necrosis
*T1+C : Dense enhancement :
-Homogeneous if small
-Heterogeneous if large
232. Coronal T2 shows well defined paravertebral mass with peripheral high signal
intensity and relatively low signal intensity centrally , mass has peripheral
low signal intensity rim (arrows) that reflects tumor capsule
233. Axial T2 shows well defined mass with heterogeneous high signal intensity in
right paravertebral region , mass protrudes toward adjacent right neural
foramen (arrow) and shows “dumbbell” configuration , mass has low signal
intensity rim (arrowhead) in periphery
234. Axial T1+C shows heterogeneous enhancement that is relatively strong
in center of mass
239. A, Coronal T2 shows well-
defined mass in right
paravertebral region ,
mass has very high signal
intensity area (arrow) in
center and low signal
intensity rim (arrowhead)
in periphery
B, Coronal T1+C fat-
suppressed shows no
enhancement of central
area (arrow) which
reflects cystic change in
mass
241. a) Incidence :
-Are benign peripheral nerve sheath tumors
-Peak presentation is between 20 and 30
years of age
-The majority of neurofibromas are solitary
and sporadic , however there is an
association with NF1
244. 1-Plain Radiography :
-Both benign and malignant tumors may erode ribs
-They may enlarge the neural foramina (dumbbell
shaped lesion)
-Scalloping of posterior vertebral bodies may occur
-They may produce a scoliosis
-Pleural effusion may occur with benign as well
as malignant neural tumor
252. 3-MRI :
*T1 :
-Hypointense
*T2 :
-Hyperintense
-A hyperintense rim and central area of low signal
resulting in a target sign may be seen due to a
dense central area of collagenous stroma
*T1+C :
-Heterogenous enhancement
253. T1+C , dumbbell shaped neurofibroma with intra and
extraspinal extension , note the displacement of the
adjacent thoracic cord (arrow)
254. Axial T2 shows well defined mass with homogeneous high signal intensity in left
paravertebral region , mass has thin low signal intensity rim (arrows) in
periphery
256. 4-Malignant Peripheral Nerve Sheath
Tumors (MPNST) :
-Are malignant forms of neurofibromas and
schwannomas
-Associated with NF1
-Imaging criteria are generally considered
unreliable in differentiating from a more
benign neurofibroma or schwannoma
257. c) Sympathetic Ganglia Tumors :
1-Incidence
2-Neuroblastoma
3-Ganglioneuroma
4-Ganglioneuroblastoma
258. 1-Incidence :
-These tumors tend to present as elongated
paraspinal masses that span multiple vertebral
levels
-Intratumoural calcification is common
-They are :
a) Neuroblastoma : young children
b) Ganglioneuroma : children and adults
c) Ganglioneuroblastoma : older children
-Neuroblastoma and ganglioneuroblastoma are
most commonly seen in children and in a child
they comprise the commonest neurogenic tumor
260. a) Incidence :
-Is a tumor of neuroblastic origin and the most
common extracranial solid childhood
malignancies and the third commonest
childhood tumor after leukemia and brain
malignancies
-The tumors typically occur in infants and very
young children (mean age of presentation being
22 months) with 95% of cases diagnosed before
the age of 10 years
263. 1-Plain Radiography :
-Appearances are non-specific , typically
shows an intrathoracic soft tissue mass
-Pressure on adjacent bones may cause
remodeling of ribs , vertebral bodies or
pedicle thinning
-Up to 30% may have evidence of
calcification on the plain film
264. Homogenous opacity lesion in the right upper and mid zone with broad base towards
mediastinum , the lesion is causing shift of mediastinum and trachea to the
contralateral side and compressing the trachea just above the carina (arrow head) ,
the lesion is extending above the clavicle (cervico-thoracic sign) and erosion of
posterior end of third and fourth ribs (Long arrow)
265. *N.B. : Cervico-thoracic sign
-A variant of the silhouette sign
-It helps to discern the anterior or posterior location of mass
in the superior mediastinum on frontal chest radiographs
-As the anterior mediastinum ends at the level of
the clavicles and as such the upper border an anterior
mediastinal lesions cannot be visualized extending
above the clavicles
-Any lesions with a discernible upper border above that
level must be located posteriorly in the chest ; i.e. apical
segments of upper lobes , pleura or posterior
mediastinum
266.
267.
268. 2-CT :
-The tumor typically is heterogeneous with calcifications
seen in 80 - 90% of cases
-Areas of necrosis are of low attenuation
-The morphology of is often most helpful with the mass
seen insinuating itself beneath the aorta and lifting it off
the vertebral column , it tends to encase vessels and
may lead to compression , adjacent organs are usually
displaced
-Lymph node enlargement is often present
-Calcification in a posterior mediastinal mass points to a
neural tumor in a kid rather than a met from somewhere
else
269. Heterogeneously enhancing mass lesion in the right posterior
mediastinum extending to middle mediastinum causing compression
of the trachea , the lesion is showing multiple small foci of
calcification (black arrows)
270.
271.
272.
273. 3-MRI :
*T1 :
- Heterogeneous and iso to hypointense
*T2 :
-Heterogeneous and hyperintense
-cystic / necrotic areas very high intensity
*T1+C :
-Variable and heterogeneous enhancement
274. 1 month old boy with mediastinal neuroblastoma , coronal T2 shows long
vertically oriented mass with homogeneous high signal intensity and
tapering appearance in left paravertebral region , invasion of vertebrae is
not seen
275. Axial T2 in a patient with a thoracic neuroblastoma shows a large right posterior
mediastinal mass extending into the spinal canal and displacing the cord laterally to
the left , the mass is hyperintense on T2
276. T1+C shows inhomogeneous enhancement of the mass which appears
to have a component arising from the neural foramen (white arrow)
278. a) Incidence :
-They tend to occur in the pediatric
population and are often asymptomatic
-Usually , patients are older than 10 years
old , compared to neuroblastoma which
occurs in patient younger than 3 years old
279. b) Location :
-Can potentially occur anywhere along the
peripheral autonomic ganglion sites , the
posterior mediastinum one of the
commonest locations (40%)
281. 1-Plain Radiography :
-All neuroblastic tumors (i.e.
ganglioneuroblastomas , ganglioneuromas
and neuroblastomas) look similar
-See Neuroblastoma
282. Chest radiograph shows a right paraspinal well-defined density in the
retrocardiac region , the right cardiophrenic angle appears normal
283. 2-CT :
-Typically seen as well circumscribed solid
encapsulated masses
-Tend to be iso to hypoattenuating to muscle
-May demonstrate calcifications (40%)
-Delayed heterogeneous uptake of contrast
284.
285.
286.
287. Paraspinal Ganglioneuroma, non-enhanced Axial CT scan reveals a
paraspinal homogeneous low attenuation fusiform mass which after
resection proved to be a ganglioneuroma
288. 3-MRI :
*T1 :
-Homogeneously low or intermediate signal
*T2 :
-Heterogenously intermediate or high signal
*T1+C :
-Ranging from none to heterogenous
enhancement
289. (a) Chest radiography shows an oblong mass in the right paraspinal region , the lateral
margins of the mass are indistinct & there is RT lower lobe pneumonia , (b) CT+C
shows that the mass is heterogenous and contains calcifications (c) T2 shows that
the mass is of high signal intensity
290. Coronal T2 shows long vertically oriented mass with heterogeneous
high signal intensity and tapering appearance in left paravertebral
region
291. , Coronal T1+C shows heterogeneous enhancement in
mass.
292. T1+C of a ganglioneuroma shows homogeneous enhancement of the
lesion , the lesion is extending from the right paraspinal region into
the epidural space through the neural foramina causing cord
compression
293. T1 of a ganglioneuroma , the sagittal views shows a well-defined solid
mass located slightly anterior to the midthoracic vertebral bodies ,
the mass extends into and widening multiple neural foramina , flow
voids within the lesion represents vascularity
295. a) Incidence :
-Uncommon peripheral neuroblastic tumor
- Most commonly in babies and in young
children
-Ganglioneuroblastoma have intermediate
malignant potential between that of
neuroblastomas and ganglioneuromas
296. b) Location :
-Can potentially occur anywhere along the
peripheral autonomic ganglion sites , the
posterior mediastinum one of the
commonest locations
300. 2-CT :
-See Ganglioneuroma + areas of bleeding
and necrosis may be as large as 4 cm and
appear to be of lower attenuation
301. CT without contrast of a ganglioneuroblastoma demonstrates a large
left heterogeneous paraspinal lesion with speckled calcifications that
are predominantly peripheral , the mass is displacing the
mediastinum to the right
302.
303. 3-MRI :
-See Ganglioneuroma + areas of hemorrhage
have a high T1 signal intensity and cystic areas
have a high T2 signal intensity
-Ganglioneuroblastomas , like neuroblastomas and
other malignant tumors have an enhancing
pattern of early enhancement followed by a
partial washout , early enhancement is indicative
of high vascularity
304. Axial T1 shows high signal intensity areas (arrowheads) that suggest
hemorrhage in center of mass
305. Axial T1+C shows heterogeneous enhancement in mass ,
enhancement is not seen in center of mass (arrowheads) and tumor
necrosis is suspected
306.
307.
308. MRI scan showing homogenous soft tissue density mass in the posterior
mediastinum
310. 1-Incidence :
-Rare tumors derived from chromaffin cells
(neuroectodermal cells) associated with
sympathetic ganglion of the autonomic
nervous system
-Paraganglioma (= chemodectoma ,
histologically similar to
pheochromocytoma) : functional tumors ,
may secrete catecholamines
311. 2-Location :
-They can arise from two major cluster of
sympathetic ganglion cells :
a) Paraaortic (aorticopulmonary)
b) Paravetebral(aorticosympathetic) location
312. -Normal anatomy of mediastinal
nervous tissues
-Most peripheral nerve tumors
originate from spinal or
proximal intercostal nerve in
posterior mediastinum
-Thoracic sympathetic trunks and
their associated ganglia are
located on side of vertebral
bodies
-Aortosympathetic paraganglia
are adjacent to sympathetic
chain in posterior mediastinum
whereas aortopulmonary
paraganglia are located along
great vessels
316. 29 year old man with posterior mediastinal paraganglioma ,
chest radiograph shows large lobulated mass in left
paraspinal area (arrow)
317. b) CT :
-Mediastinal paragangliomas are seen in as a
mass in a characteristic location in the
paraaortic region of the middle mediastinum or
paravetebral region of the posterior mediastinum
corresponding to major cluster of sympathetic
ganglion cells
-Uncomplicated mediastinal paragangliomas
demonstrate intense contrast enhancement
318. 29 year old man with posterior mediastinal paraganglioma , CT+C
shows hyperenhancing mass with cystic change (arrowhead) in left
posterior mediastinum
319. 29 year old man with posterior mediastinal paraganglioma , CT shows
linear and punctate foci of calcification (arrow) within tumor mass
320. Axial CT+C shows heterogeneous mass between ascending aorta and
pulmonary trunk , there are intratumoral vessels (arrows), which suggest
hypervascularity of tumor , pulmonary trunk is compressed by mass and
invasion is suspected
321.
322. c) MRI :
-Mediastinal paraganglioma shows
enhancement on T1+C with conspicuity of
the lesion hightlighted by flow avoid in the
adjacent mediastinal vessels on spin-echo
sequences
323. Axial T2 fat-suppressed shows heterogeneous high signal intensity in
mass and flow voids (arrows) that reflect high flow in intratumoral
vessels
325. a) Causes :
-Is a response to erythropoiesis failure in bone
marrow :
1-Myeloproliferative Disorders :
-CML
-Polycythemia Vera
2-Haemoglobinopathies :
-Sickle cell disease
3-Thalassemia
326. b) Radiographic Features :
-Posterior mediastinal masses , these are
paraspinal masses that may be unilateral or
bilateral and have smooth sharply delineated
often lobulated margins
-Suspect diagnosis if :
1-Multiple bilateral posterior mediastinal masses
2-Cortical bone changes by CT
3-Clinical history of anemia
4-Marked contrast enhancement
327. Left : There are large paraspinal masses (white arrows) with smoothly
marginated lobulated contours , all of the ribs (red arrow) are
expanded and the overall bone density is increased
Right : Large paraspinal masses are seen (white arrows)
329. Frontal chest film (a) and scout view (b) show a bulging of the right
paraspinal line, CT scans (c-f) show bilateral soft-tissue paraspinal
masses, representing extramedullary hematopoiesis, in a young
thalassaemic patient
336. a) Causes :
-Infection of the soft tissues surrounding the
spine due to a suppurative bacterial or
mycobacterial infection with phlegmon
formation
337. b) Radiographic Features :
-High signal intensity fluid collections on T2
-Peripheral enhancement in areas of
reactive granulation tissue on post
contrast
-May be associated with intervertebral disc
space infection
-Tubercular abscesses may eventually
calcify
338. PA chest radiograph , the left paraspinal line (arrow) is seen separate
and distinct from the vertebral body (black arrowhead) and the
descending thoracic aorta (white arrowhead)
339. CT shows the left paraspinal line , the descending aorta holds the
pleural reflection (arrow) away from the vertebral body which allows
the lung soft tissue interface to be more tangential to the x-ray beam
and therefore visualized as a line
341. Paraspinal abscess , (a) PA chest radiograph shows a mass (arrow) effacing
the left paraspinal line , the lateral wall of the descending aorta is seen as a
separate entity (arrowhead) , (b) CT shows a paraspinal abscess (arrow)
effacing the paraspinal lines , the air soft tissue interface between the lung
and aorta remains intact (arrowhead) , thereby preserving the normal
radiographic appearance of the lateral aortic wall
343. Descending aortic aneurysm , (a) PA chest radiograph shows lateral
displacement of the lateral margin of the descending thoracic aorta
due to an aortic aneurysm (arrowheads) , (b) CT also demonstrates
the aneurysm (arrow)
347. Duplication cyst in a 10-year-old girl with cough, (a) Chest radiograph
shows a round area of increased opacity that deforms the
azygoesophageal recess (arrow), (b) CT+C shows a thin-walled
water-attenuation cyst adjacent to the esophagus (arrow)
350. Neurenteric cyst in a 30 year old female with flank pain , (a) Chest radiograph shows a
well defined round mass (arrow) in the lower thoracic region , (b- c) Both axial T1 and
coronal T2 show a large mass that is of homogenous high signal intensity in the right
paravertebral region (arrow) , the cyst presumably contains proteinaceous fluid
352. a) Incidence :
-This follows extension of a pancreatic
pseudocyst in the posterior mediastinum
-This occurs via the esophageal or aortic
hiatus and therefore lies adjacent to the
esophagus
-Most case are seen in adults with clinical
features of a chronic pancreatitis (it can
also occur in children following trauma)
355. Initial examination showed an intrathoracic mass overlying the left
margin of the heart (arrowheads) , no interstitial pulmonary edema
was noted ,small pleural effusions are shown
356. 2-CT :
-A thin walled cyst continuous with the
pancreas
-Left sided or bilateral effusions
357. Pancreatic pseudocyst in a 40 year old male with a 3 week history of
chest and epigastric pain , CT+C shows bilateral pleural effusion
and periaortic fluid collection (arrow) displacing the esophagus
(arrow)
358. Pancreatic pseudocyst in a 45-year-old woman with a 2-week history of
dysphagia and chest pain, (a) CT+C shows bilateral pleural effusion and a
thin-walled periaortic cystic lesion that displaces the esophagus (arrow)
anteriorly, (b) Axial T1 shows a low-signal-intensity cyst (arrow)
359. CT+C , a large cystic lesion is compressing the heart ,
predominantly the left ventricle (arrowheads)
361. Bochdalek Hernia: Axial CT of the lung bases shows abnormal
herniation of abdominal fat contents into the lower posterior left
hemithorax through the left hemidiaphragm (arrows)
362. On a frontal chest radiograph (a), the distal third of the
azygoesophageal recess demonstrates an abnormal contour and
bilateral convexity, lateral chest X-ray (b) demonstrates a
retrocardiac hyperlucency mass consistent with hiatal hernia
364. a) Incidence :
-A rare lesion due to protrusion of the spinal
meninges through an intervertebral
foramen
-Usually asymptomatic
-It is commonly associated with
neurofibromatosis (as neurofibroma)
366. 1-Plain Radiography :
-A posterior mediastinal mass (often with
pressure deformity on the adjacent bone)
-It is indistinguishable from neurofibroma
367. X Ray of the chest showing meningocele as a mass lesion‑
368. 2-CT :
-A fluid filled mass (rather than solid)
-Intrathecal contrast medium shows flow into
the lesion
369. Lateral thoracic meningocele in a 37-year-old man with
neurofibromatosis, CT scan shows a low-attenuation mass
protruding from the enlarged left intervertebral foramen