Transcript CONTRIBUTION OF MRI IN THE DIAGNOSIS OF MUSCLE HEMANGIOMA

Bouaziz.I, Abdelkefi.M , Guermazi Y , Haddar S,
Kobbi I, Abid H , Ben Mahfoudh KH , Mnif J
Radiology department,CHU Habib Bourguiba,Sfax
MK3
OBJECTIVE:
The purpose of this study was to determine whether MR
imaging features can suggest the diagnostic of muscular
hemangiomas.
MATERIALS AND METHODS:
We reviewed MR imaging studies of 2 patients aged 18
and 25, explored for a soft-tissue mass.
Masses were evaluated for signal intensity on T1 and T2
weighted images, for enhancement with gadolinium
administration, and for morphology (lobulation, septation,
central low-intensity dots).
 Case 1:
 30 old patient .
 Knee pain.
T1
T2
T2 FAT SAT
•On T1:low-to-intermediate signal intensity
,lobulated mass with peripheral high signal
intensity due to fat overgrowth.
T1 FAT SAT GADO
•On T2: areas of high signal intensity due to
vascular tissue and intermediate signal intensity
due to fat.
•Intense and homogenous enhancement
 Case 2:
 25 old patient.
 post traumatic pain in the left calf.
 Ultrasound: hyperechoic, hetregenous and vascularized,
oval mass, of the gastrocnemius left muscle.
 oval mass, of the
T1
gastrocnemius muscle,
hypointense on all sequences.
T2
 Accentuated hypointensity in
the periphery ,in relation with a
deposit of hemosiderin.
 T2 hyperintensity in the center,
T1
T1 FAT SAT GADO
with gradually enhancement
after gadolinium injection, in
connection with intralesional
venous maze.
 It is surrounded by a peripheral
hyperintensity in T1 and T2
canceled in fat sat.
DISCUSSION
 Soft-tissue hemangiomas are common neoplasms of benign
histologic origin.
 They are the most common of the angiomatous lesions and
represent up to 7% of all benign soft-tissue tumors in the
general population .
 Women are more often affected than men.
 Hemangiomas are the most frequently diagnosed soft-tissue
neoplasm in children.
 Histologically, soft-tissue hemangiomas are subdivided
into five categories, depending on the predominant type of
vascular channel identified.
 These subdivisions include capillary, cavernous,
arteriovenous, venous, and mixed variations .
 Of these categories, capillary hemangiomas are the most
common .
 They are usually diagnosed during the first few years of life
and are found in the skin, subcutaneous tissue, or vertebral
bodies. Microscopically, capillary hemangiomas are composed
of a disordered array of capillary-sized vessels. Most of these
hemangiomas spontaneously involute .
 Cavernous hemangiomas are larger and deeper and occur later
in life.
 They are often intramuscular.
 They are composed of dilated, blood-filled spaces lined by
flattened endothelium. Calcification is common.
 They do not spontaneously involute and therefore may require
surgical intervention .
 Arteriovenous hemangiomas may be deep or superficial.
 They represent an abnormal communication between arteries
and veins and can cause a variable degree of shunting. The
composition of these lesions reflects a persistent fetal capillary
bed.
 Venous soft-tissue hemangiomas typically involve deep
structures and can classically be found in the retroperitoneum,
mesentery, and extremities.
 Histologically, they are composed of thicker-walled vessels
containing smooth muscle cells.
 The term “haemangioma” is commonly misused to
describe any type of vascular abnormality, including
vascular malformation.
 In addition to their vascular components, angiomatous
tumors can contain thrombus, calcification,
hemosiderin, fat, smooth muscle, and fibrous tissue .
 This is particularly true of cavernous hemangiomas.
 The most common association is that of reactive fat
overgrowth. In fact, overgrowth of adipose tissue can
be so prominent that in the past, these lesions were
classified as angiolipomas.
 Venous malformation can occur in every muscle group
with pain and swelling being the usual complaints.
Vascular malformations are usually present at birth,
grows proportionally with the child and never
involutes.
 Intramuscular haemangiomas account for 0.8% of all
haemangiomas.
 It occurs most commonly in young adults with 80–90%
presenting in individuals younger than 30 years.
 Clinically they manifest with a mass without any diagnostic
features. Pain is a cardinal symptom in 60% of the cases,1
with the lower extremity being the commonest site of
involvement.
 The quadriceps is the most frequently affected muscle.
Intramuscular haemangiomas progressively enlarge but
never metastasize. There is a 9% recurrence rate after
surgical excision.
 Plain radiographs of soft tissue haemangioma may
appear only as a non-specific soft tissue mass and in
25–30% of cases it shows phlebolith.
 Periosteal reaction adjacent to the haemangioma may
mimic osteomylitis or bone tumour.
 At nonenhanced CT, an ill-defined mass of similar
attenuation to muscle may be identified. Phleboliths too
small to identify on radiographs can be revealed. After
administration of contrast material, significant
enhancement is typical.
 serpentine vascular structures may be depicted as well as
surrounding adipose overgrowth.
 US can demonstrate a complex mass. If phleboliths are
abundant, acoustic shadowing may also be
documented .
 Doppler evaluation may show low-resistance arterial
flow with forward flow during both systole and
diastole .
 Currently, the standard for imaging evaluation of soft-
tissue hemangiomas is MR imaging .
 MRI is important for further characterization of the
substance and extent of the soft tissue haemangioma.
 Typically, all sequences show a heterogeneous mass
(although lesions measuring under 2 cm tend to be
homogeneous), reflecting the mix of tissues present.
 T1-weighted images best reveal areas of high-signal-
intensity adipose tissue, most prominent along the
circumference of the vascular complex. This fatty
tissue may reflect muscle atrophy secondary to chronic
vascular insufficiency caused by the steal
phenomenon.
 In some patients, the fat overgrowth is so prominent
that these lesions are mistaken for lipomas .
 On T2-weighted images, hemangiomas have been
described as having a multilobulated high-signalintensity configuration interspersed with linear and
lacelike areas of low or intermediate signal intensity .
 the distinctive septate–lobulated appearance on T2-
weighted imaging correlated with fibrous and fatty
septa(low signal) between endothelial-lined vascular
channels (high signal) identified on histologic
examination.
 The central angiomatous core of the neoplasm shows
high signal intensity on T2-weighted images. As on
contrast-enhanced CT images, the serpentine nature of
the hemangioma may be depicted.
 If blood flow through these vascular channels is rapid
enough, the signal may remain low in intensity with all
MR imaging sequences. If gadolinium contrast material
is administered, prominent enhancement of the
angiomatous tumor is expected .
 Characteristic tubular or serpentine components are
orientated along the muscular long axis.
 Thrombi are hyperintense on T1-weighted and
hypointense on T2-weighted sequences
 Central low-intensity dot sign on T2-weighted imaging in
hemangiomas has been described . This sign is highly
specific for hemangiomas compared with malignant softtissue masses.
 These rounded foci of low signal intensity seen in
hemangiomas may represent fibrofatty septa seen in
cross section, or hyalinized or thrombosed vascular
channels
 Fast flow in blood vessels is a likely cause in some cases
because the central low-intensity dots disappear after
gadolinium administration .

This central low-intensity dot has also been described in
benign neurofibromas , where it produces a so-called
targetlike appearance.

The pattern of enhancement is helpful in distinguishing
between neurofibromas and hemangiomas. Because the
central low-intensity dot in benign neurofibromas is caused
by dense collagen, it is not likely to exhibit enhancement with
gadolinium as hemangiomas do.
 MRI may help to differentiate between types of
haemangiomas.
 Lesions with large cystic spaces are cavernous whereas
arteriovenous haemangiomas show more prominent
fast flow serpentine vessels. Venous haemangiomas,
on the other hand, show slow-flow serpentine vessels.
 MRI may also help to differentiate between haemangiomas
and malignant soft-tissue masses .
 The T2 signal intensity of hemangiomas is greater than
that of malignant soft-tissue masses.
Hemangiomas have high T2 values, which may reflect
pooling of the blood within cavernous spaces and slow flow
within dilated venous channels

Intense enhancement, is supportive of the diagnosis of
hemangioma but should be used in corroboration of other
findings to reach the diagnosis.
 Angiography should be considered if MRI has not
provided sufficient information about the relationship
between the tumour and a neurovascular bundle.
 In patients in whom excision is impractical,
embolization or radiotherapy should be considered. In
cases of recurrence adjuvant therapy (interferon-) may
be considered.
CONCLUSION
 Morphological caracterisations, signal intensity and
enhancement with gadolinium allowed to diagnose
muscular hemangiomas and differentiation from other
soft-tissue masses