valsalva maneuver

1- the patient is asked to do valsalva maneuver while the common femoral vein is being imaged transversely.

2-a normal response results in complete retardation of flow within the vein and resultant venous dilatation , the diameter increasing by at least 50%.

3-absence of this normal response is seen in intra luminal venous thrombosis,or external pressure applied on the vein by a pelvic tumor .

4- it could be done also with congestive heart failure

respiratory variations of the spectral wave form

1- the external iliac artery and common femoral veins should have a phasic wave form.

2-if this is lost,and the wave form is flat,then this is suspicious of either external compression from a pelvic mass or a more proximal obstructing intra luminal thrombus.

calf vein imaging

1-this is not routinely performed at every centre.

2-essentially, each of the calf arteries is accompanied with pair of veins.

3-identify first the artery and then apply distal calf compression to visualise the paired veins.

4-spontaneous flow is generally absent below knee.

5-the posterior tibial vein can be visualised by placing the probe to the medial side of the tibia.these veins are more superficially placed than the deeper sets of peroneal veins.

6-the anterior tibial veins can be visualised along the lateral aspect of the tibia.as these veins lie superficially.deeper to it ,we can visualise peroneal veins.

7-peroneal veins could be seen posteriorly through the lower leg.

8-you can visualise the calf veins while the patient is in supine position,or the patient sit up and the legs is suspended over the edge of the table with the foot on a rest.this has the effect to improve visualisation.

9-diagnostic criteria for calf veins is the same as that of the veins above knee.

10-at present,the limitation of this technique as that it will only show global thrombosis either confined to one set of veins, or through out multiple calf veins.it will not reliably and routinely detect small focal segments of thrombosis.therefore,equivocal scans or persistent symptoms may require clarifying venogram.although this could be imperfect in detection of small focal calf thrombi due to poor or non filling of the affected segment.

calf vein imaging

1-this is not routinely performed at every centre.

2-essentially, each of the calf arteries is accompanied with pair of veins.

3-identify first the artery and then apply distal calf compression to visualise the paired veins.

4-spontaneous flow is generally abscent below knee.

lower limb veins thrombosis

a positive diagnosis of deep venous thrombosis using colour flow imaging depend upon a number of factors,which include:

1-lack of spontaneous flow.

2-presence of intra-luminal reflective material.

3-vein dilatation.

4-poor response to augmentation maneuver.

5-non compressibility of the vein.

color flow imaging

1-use linear array probe 5 - 7.5 mhz.
2-patient supine with slight abduction of the thigh 10-15 degree.
3-gel applied from groin to adductor canal.
4-first,imaging done in transverse plane to identify femoral vein(medial) and artery(lateral).
5-spectral doppler analysis of both vessels.
artery--->triphasic wave form.
vein --->monophasic wave form.
6-examine external iliac vein using spectral wave form by one or the two following
a - normally , it is monophasic wave form with increase with expiration and decrease with inspiration.
-absence of this variation means----->proximal thrombosis or
----->proximal compression of the vein.
b-by valsalva maneuver.
7-by this point,imaging will be done by longitudinal scan.
8-examination of--->common femoral vein.
--->superficial femoral vein.
--->profunda femoris vein.
we can increase doppler flow by--->compression technique
and by--->by power doppler imaging.
8-turn patient in lateral decubitus with knee flexed by 20-25 degrees.
9-popliteal vein is seen anterior to popliteal artery.
10-examine popliteal vein up to adductor canal and inferiorly to tibio-peroneal trunk.
11-diagnostic criteria
*sponteneous flow:
present in patent vessel
not present in thrombotic vessel.
*intraluminal reflective material:
not present in patent vessel.
present in thrombotic vessel.
*response to distal augmentation:
present in patent vessel.
not present in thrombotic vessel.
*response to probe compression:
present in patent vessel.
not present in thrombotic vessel.
*venous dilatation:
not present in patent vessel.
present in thrombotic vessel.
*spectral wave form:
present,phasic in patent vessel.
not present in thrombotic vessel.

iliac assessment:
spectral variation is seen in patent vessel.
not seen in thrombotic vessel.
response to valsalva maneuver is seen in healthy vein
not present in thrombotic vessel.

real time compression ultrasound

1- put the probe perpendicular to the vascular flow.
2-start at groin.
3-identify common femoral vein(medial) and artery(lateral).
4-use linear array probe 5-7.5 mhz.
5-make a light pressure so the vein will not be closed.
6-then put further pressure on the vein
if it is collapsed completely(both walls opposed to each other)---> it is a healthy vein
if it is not collapsed at all or collapsed partially---> vein contains thrombus.
7-reflective thrombus could be seen within the lumen of the vein.
8-apply this technique from the groin to the adductor canal with 1 cm intervals.
9-to examine the popliteal vein turn the patient into lateral decubitus position with knee flexed.
10-then from posterior fossa , the vein will be anterior to the artery.
11-popliteal vein is followed upward to adductor canal and inferiorly to tibio-peroneal trunk.
12-at this point , examination was ended.

In the article Bone Tumors - Differential diagnosis we discuss a systematic approach to the differential diagnosis of bone tumors and tumor-like lesions. In this article we will discuss the differential diagnosis of well-defined osteolytic bone tumors and tumor-like lesions.
Abbreviations used:
-ABC = Aneurysmal bone cyst
-CMF = Chondromyxoid fibroma
-EG = Eosinophilic Granuloma
- GCT = Giant cell tumour
-FD = Fibrous dysplasia
- HPT = Hyperparathyroidism with Brown tumor
-NOF = Non Ossifying Fibroma SBC = Simple Bone Cyst


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On the above the most common well-defined bone tumors and tumor-like lesions.These lesions are sometimes referred to as benign cystic lesions, which is a misnomer since most of them are not cystic, except for SBC and ABC. It is true that in patients under 30 years a well-defined border means that we are dealing with a benign lesion, but in patients over 40 years metastases and multiple myeloma have to be included in the differential diagnosis



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On the above a table with well-defined osteolytic bone tumors and tumor-like lesions in different age-groups.

-Notice the following:

-In patients <>

-In patients > 40 years metastases and multiple myeloma are by far the most common well-defined osteolytic bone tumors.

- Patients with Brown tumor in hyperparathyroidism should have other signs of HPT or be on dialysis.

-Differentiation between a benign enchondroma and a low grade chondrosarcoma can be impossible based on imaging findings only.

- Infection is seen in all ages.

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- Most bone tumors present as well-defined osteolytic lesions, sometimes referred to as 'bubbly lesions'.
-It is important to have a good differential diagnostic approach to these lesions.
-You can use the table above, but another way to look at the differential diagnosis of well defined osteolytic bone lesions is to use the mnemonic Fegnomashic, which is popularized by Clyde Helms (1).
-Some prefer to use the mnemonic Fogmachines, which is formed by the same letters, but is a real word.


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Fibrous Dysplasia

Fibrous dysplasia
-Fibrous dysplasia is a benign disorder characterized by tumor-like proliferation of fibro-osseus tissue and can look like anything.
-FD most commonly presents as a long lesion in a long bone.
-FD is often purely lytic and takes on ground-glass look as the matrix calcifies.
-In many cases there is bone expansion and bone deformity.
-The ipsilateral proximal femur is invariably affected when the pelvis is involved.
-When FD in the tibia is considered, adamantinoma should be in the differential diagnosis. Discriminator:
If periosteal reaction or pain is present, exclude fibrous dysplasia, unless there is a fracture.


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Enchondroma

• left
Fat suppressed coronal PD-image of the knee. Typical enchondromas in the femur and tibia as seen frequently as coincidental finding in MR-examinations.
middle
Well-defined lytic lesion in the rib with cortical thinning.
right
Well-defined lytic lesion with a sclerotic margin and without calcifications in the end phalanx.

Enchondroma

Enchondroma
-Enchondroma is a benign cartilage tumor.
-Frequently it is a coincidental finding.
-In the phalanges of the hand it frequently presents with a fracture.
-It is the most common lesion in the phalanges, i.e. a well-defined lytic lesion in the hand is almost always an enchondroma.
-In some locations it can be difficult to differentiate between enchondroma and bone infarct.
-It is almost impossible to differentiate between enchondroma and low grade chondrosarcoma based on radiographic features alone.
-Ollier's disease is multiple enchondromas.
-Maffucci's syndrome is multiple enchondromas with soft tissue hemangiomas.
-Features that favor the diagnosis of a low-grade chondrosarcoma:
Higher age Size > 5 cm
Activity on bone scan
Fast enhancement on dynamic contrast enhanced MR series
Endosteal scalloping of the cortical bone
Discriminators :
Must have calcification except in phalanges.
No periostitis.


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EG

- is a non-neoplastic proliferation of histiocytes and is also known as Langerhans cell histiocytosis.

-It should be included in the differential diagnosis of any sclerotic or osteolytic lesion, either well-defined or ill-defined, in patients under the age of 30.

-The diagnosis EG can be excluded in age > 30.

-EG is usually monostotic, but can be polyostotic.

- left

Osteolytic lesion arising from the neurocranium with associated soft tissue swelling.

middle

Mixed lytic-sclerotic lesion, not well-defined with solid periosteal reaction.

right

Sharply defined osteolytic lesion of the skull. There is no 'button sequestrum', which is more or less pathognomonic.Discriminator: Must be under age 30.

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giant cell tumor

Giant cell tumor
-Giant cell tumor is a lesion with multinucleated giant cells.
-In most cases it is a benign lesion.
-Malignant GCT is rare and differentiation between benign or malignant GCT is not possible based on the radiographs.
-GCT is also included in the differential diagnosis of an ill-defined osteolytic lesion, provided the age and the site of the lesion are compatible.
-Discriminators:
Epiphyses must be closed.
Must be an epiphyseal lesion and abut the articular surface.
Must be well-defined and non-sclerotic margin. Must be eccentric.


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NOF: typical presentation as an eccentric, multi-loculated subcortical lesion with a central lucency and a scalloped sclerotic margin.

NOF
-NOF is a benign well-defined, solitary lesion due to proliferation of fibrous tissue.
-It is the most common bone lesion.
-NOF is frequently a coincidental finding with or without a fracture.
-NOF usually has a sclerotic border and can be expansile.
-They regress spontaneously with gradual fill in.
-NOF may occur as a multifocal lesion. The radiographic appearance is almost always typical, and as such additional imaging and biopsy is not warranted.
Discriminators:
Must be under age 30.
No periostitis or pain.


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osteoblastoma

Osteoblastoma
-Osteoblastoma is a rare solitary, benign tumor that produces osteoid and bone.
-Consider osteoblastoma when ABC is in the differential diagnosis of a spine lesion (figure).
-A typical osteoblastoma is larger than 2 cm, otherwise it completely resembles osteoid osteoma. Discriminator: Mention when ABC is mentioned.


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bone metastases

Metastases
-Metastases are the most common malignant bone tumors.
-Metastases must be included in the differential diagnosis of any bone lesion, whether well-defined or ill-defined osteolytic or sclerotic in age > 40.
-Bone metastases have a predilection for hematopoietic marrow sites: spine, pelvis, ribs, cranium and proximal long bones: femur, humerus.
-Metastases can be included in the differential diagnosis if a younger patient is known to have a malignancy, like neuroblastoma, rhabdomyosarcoma, retinoblastoma.
-Most common osteolytic metastases: kidney, lung, colon and melanoma.
-Most common osteosclerotic metastases: prostate and breast.
Discriminator: Must be over age 40.


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multiple myeloma

Multiple Myeloma
-Multiple myeloma must be included in the differential diagnosis of any lytic bone lesion, whether well-defined or ill-defined in age > 40.
-The most common location is in the axial skeleton (spine, skull, pelvis and ribs) and in the diaphysis of long bones (femur and humerus).
-Most common presentation: multiple lytic 'punched out' lesions.
-Multiple myeloma doe not show any uptake on bone scan.
-Discriminator: Must be over age 40.


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multiple myeloma

Multiple Myeloma (2)
Differential diagnosis:
multiple lesions: metastases.
solitary lesion: chondrotumor, GCT and lymphoma.
- On the above a CT-image of a patient with multiple myeloma.Notice the numerous osteolytic lesions and permeative cortical destruction pattern.
In the left sacral wing there is a larger lesion with a high density due to replacement of fatty bone marrow by myeloma (red arrow).


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SBC: well-defined osteolytic lesion without expansion of the proximal meta-diaphysis of the humerus with pathologic fracture

Solitary Bone Cyst
-Solitary bone cyst, also known as unicameral bone cyst, is a true cyst.
- Many well-defined osteolytic lesions are often called cystic, but this is a misnomer.
-SBC frequently presents with a fracture. Sometimes a fallen fragment is appreciated. Predilection sites: proximal humerus and femur.
-Usually less expansion compared with ABC.
-Differential diagnosis: ABC, FD when cystic. SBC may migrate from metaphysis to diaphysis during growth of the bone.
-Discriminators:
Must be under age 30.
Must be centric


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Hyperparathyroidism
-Brown tumors can occur in any bone and present as osteolytic lesions with sharp margins. Septa and ridges may be seen.
-Differential diagnosis: ABC, metastases and GCT depending on location and age.
-On the above a patient who had a nefrectomy for renal cell carcinoma and who was on dialysis. Multiple well-defined osteolytic lesions were found on a follow up CT scan.
-The differential diagnosis included metastases and Brown tumors in hyperparathyroidism. Biopsy revealed Brown tumor.
-Discriminators: Must have other signs of HPT.


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Infection
-Infection or osteomyelitis is the great mimicker of bone tumors.
-It has a broad spectrum of radiographic features and occurs at any age and has no typical location.
-In the chronic stage it can mimic a benign bone tumor (Brodies abscess).
-In the acute stage it can mimic a malignant bone tumor with ill-defined margins, cortical destruction and an aggressive type of periostitis.
-Only when there is a thick solid periosteal reaction we can recognize the non-malignant underlying process
-Discriminators:
None.


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Chondroblastoma: notice extensive edema (middle) and fluid-fluid level due to secondary ABC.

Chondroblastoma

-The patella, carpal and tarsal bones can be regarded as epiphysis conceirning.

- the differential diagnosis.

- On the above a chondroblastoma located in the patella.Discriminators :

- must be under age 30.

-must be in the epiphysis.

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Chondromyxoid Fibroma
-Chondromyxoid Fibroma is a rare lesion.
-CMF resembles NOF.
-Preferential sites: proximal tibia and foot.
- Although the name suggests that CMF is a chondroid lesion, calcifications are usually not seen. On the above images of a CMF.
- There is an eccentric osteolytic lesion in the metaphysis of the proximal tibia. On the inner side there is a sclerotic margin. On the outer side there is a regular cortical destruction with peripheral bone layer.
-The MR also shows a sclerotic margin with low signal intensity
-Discriminators : Mention when an NOF is mentioned.