Lecture no. 3 Prepared by Dr.Salah Mohammad Fatih MBChB,DMRD,FIBMS(radiology)

Multiple focal lesions

 Metastases & multiple myeloma are most common cause of obvious multiple lytic lesions in the bone.

metastases  Is the commonest malignant bone tumor.  Those bones contains red marrow are the commonest site to be affected, namely spine, skull, ribs, pelvis, humeri & femora.

Types of metastases  Lytic secondary deposit;  Sclerotic metastases;  Mixed lytic & sclerotic secondary deposits; 

 Sclerotic bone metastases Most commonly arises from prostate cancer, but also arise from breast, lung and carcinoid

CT: Osteolytic lesions  Most commonly arises from breast, lung, thyroid, renal, melanoma, and gastrointestinal malignancies

CT: Mixed lesions / mixture of osteoblastic and osteolytic lesions / seen in breast cancer

Lytic secondary deposit;  in the adult most commonly from, breast & bronchus & less commonly from carcinoma of the thyroid, renal, colon in the children from neuroblastoma. Radiologically appear as a well-defined or ill-defined areas of bone destruction without sclerotic rim. Sclerotic metastases;  in the men most commonly from prostate & in the female from Ca breast, it appear as ill-defined areas of increased density of varying sizes with ill-defined margin. Mixed lytic & sclerotic secondary deposits;  they are most commonly from Ca breast

Notes;  bone expansion uncommon in metastases except in Ca thyroid & kidney.  periosteal reaction is uncommon with metastases except in neuroroblastoma.  Isotope scan is much more sensitive than plain film in detecting bone metastases & if multiple areas of increased activity are seen in a patient with known primary Ca, then the Dx of metastases is virtually certain.

 MRI is better than isotope scan for detecting & it shows more metastases but is more difficult to survey the whole skeleton with MRI.  CT less sensitive than MRI for detecting metastases, but can demonstrate lytic & sclerotic metastases & the image should be reviewed on bone windows.

Multiple myeloma  They are more commonly seen in active heamopoetic areas.  It is resemble lytic metastases but it is often better defined.  Diffuse marrow involvement may cause generalized loss of bone density producing a picture similar to that of osteoporosis.  Most meyloma deposite show increased activity on isotope scan

1. Osteoporosis. 2. Osteomalacia. 3. Hyperparathyroidism. 4. Multiple myeloma.

 Radiographic density of the bone depend on the amount of calcium present in the bone.  decrease in bone calcium lead to decrease in bone density.

 Osteoporosis is the consequence of a deficiency of protein matrix(osteoid) & decrease amount of the normal bone (i.e. loss of bone mass) while remaining bone is normally mineralized (microstructure of the bone remain normal & histologically also normal)

 Osteoporosis predispose to fractures, specially vertebral bodies & hips.

1-Idiopathic; according to the age, subdivided to;  Juvenile  Senile  Postmenopausal; up to 50% of female over 60 years of age have osteoporosis. 2-Cushing’s disease & steroid therapy. 3-disuse

 Change in bone density usually unapparent until % of the bone mass has been lost.  Decreased cortical thickness.  Decreased no. of the trabeculae present in the bone.

Empty box Prminent vertical trabicuale VB compression fracture Generalized decrease in bone density

 Changes best seen in the spine.  Resorption of the horizontal trabeculae.  Empty box ; apparent increased end plate density due to Resorption of the spongy bone.  VB compression fracture; wedged or biconcave types with apparent widening of the disc spaces

 Local decreased bone density caused by localized pain or immobilization of a fracture

Indistinctness of the cortex of the right femoral head and osteopenia of the entire femoral head

 There is poor mineralization of osteoid.  If occur before epiphyseal closure, it known as rickets.  If occur in adult,it known as osteomalacia.

Rickets

The anterior ends of the ribs are quite abnormal in this patient, with splaying at the costochondral junction Rickets (rachitic rosary)

 The changes are maximal where bone growth is occur, so they best seen in the knees, wrists & ankles 1. Loss of provisional zone of calcification. 2. Indistinct metaphyses & metaphyses become irregular and cupped. 3. Wide growth plate. 4. decreased bone density. 5. Deformities of the bones occur because of bone softening. 6. Greenstick fractures are common

Osteomalacia with looser’s zone

 Radiological findings; 1. Decreased bone density. 2. Looser’s zones; are short lucent band running through the cortex at the Rt angles & may have sclerotic margin, commonest site are scapula, medial aspect of femurs,& pubic rami & ribs 3. Bone deformity due to bone softening e.g. biconcave vertebra bodies

 Cause mobilization of the calcium from the bone, resulting in a decreased bone density.  Hyperparathyroidism could be primary hyperparathyroidism (90 percent due to an adenoma) or secondary hyperparathyroidism due to renal dysfunction.

 Many patients with primary hyperparathyroidism present with renal stone & minority present with radiologically detected bone changes.

 Features of both primary & secondary hyperparathyroidism are similar except that brown tumors are much rarer & vascular calcification is commoner in secondary hyperparathyroidism

Hyperparathyroidism from renal osteodystrophy.

1. Generalized decrease in bone density. 2. The hallmark of hyperparathyroidism is subperiosteal bone Resorption. 3. Soft tissue calcification; vascular & chondrocalcification sometime occur. 4. Brown tumor are occasionally present which are small lytic lesion which could be single or multiple

 Causes; 1. Sclerotic metastases, commonest cause. 2. Osteopetrosis (marble bone disease); congenital, bone sclerotic & brittle leading to multiple fractures. 3. Myelosclerosis;there is replacement of the bone marrow by fibrous tissue & lay down of the bone which is usually appear as patchy areas of sclerosis

Osteopetrosis

1.Paget’s disease 2.hemolytic anemia

 Usually is the chance finding in elderly.  One or more bones may be affected, the usual sites are pelvis, spine, skull & long bones

Paget’s disease

Paget's dsease

 Cardinal features are ;  thickening of the trabeculae & the cortex, causing increase in bone density & loss of corticomedullary differentiation.  Enlargement of the affected bone.  Bone softening causes bowing & deformity of the bones & pathological fracture may occur

 There are many types of hemolytic anemia, but radiological changes are seen in main two types; thalassaemia & sickle cell disease.  Both causes bone marrow hyperplasia, but sickle cell disease also may show evidence of bone infarction & infection

Thalassemia

 Thinning of the cortex & bone expansion.  Resorption of some trabeculae & remaining trabeculae become thick & prominent.  In the skull; it cause widening of the deploe & perpendicular striation occur which is known as ‘ Hair-on-end’.  The ribs may enlarged & phalanges may become rectangular.

Prepared by Dr.Salah Mohammad Fatih MBChB,DMRD,FIBMS(radiology)

Imaging technique  Plain film remains important for imaging the joint, but MRI is being increasingly used & specially useful for;  Meniscal & ligamentous tear in the knee.  Rotator cuff tear of the shoulder.  Avascular necrosis in the hip joint.  Septic arthritis

 Arthrography; involve injection of the contrast media in to the joint space.  MR arthrography has role in the shoulder & wrist joints.

Plain film signs indicating presence of arthritis 1-Joint space narrowing. 2-Soft tissue swelling. 3-Osteoporosis.

1-Joint space narrowing;  It occur in all forms of joint diseases except avascular necrosis.

2-Soft tissue swelling;  Periarticular soft tissue swelling is a feature of inflammatory & infective arthritis.  Discrete asymmetrical periarticular soft tissue swelling can be seen in gout due to gouty tophi

3-Osteoporosis;  Occur in many type of painful conditions & underuse of the bones is an important cause.

 Diagnosis of arthritis

To Dx arthritis, it is important to have the following information; 1- Is more than one joint involved? RA, typically involve several joint while infection & synovial tumors usually involve single joint.

2-Which joints are involved? RA virtually involve the hand & feet, principally MCP, PIP, wrist joint &MTP. Psoriatic arthritis usually affect the DIP. Gout typically involve MTP of the big toe. OA when seen in the hands,it almost always involves DIP& often affect the CM joint of the thumb & in the large joints, it commonly involve hip& knee, but relatively rare in the ankle, shoulders & elbow joints unless there is some underlying causes. Neuropathic arthritis ; Diabetic affect ankles & feet while syringomyelia affect shoulders, elbows & hands

3-Is a known disease present ? e.g hemophilia, DM