Musculoskeletal System

Question 1

What conditions show soft tissue calcification and or ossification?

Answer 1

Generalized conditions 1. Metabolic disorders With hypercalcaemia Hyperparathyroidism Hypervitaminosis D Idiopathic hypercalcaemia Milk-alkali syndrome
Without hypercalcaemia Chronic renal disease with secondary hyperparathyroidism Hypoparathyroidism Pseudo- and pseudopseudohypoparathyroidism Gout Ochronosis (alkaptonuria)

2. Vascular disorders
   Arterial and venous Connective tissue associated with oedema
3. Infection
   Bacterial Miliary tuberculosis Leprosy (nerves) Parasitic Cysticercosis Guinea worm (dracunculosis) Loa-loa Armillifer armillatus
4. Connective tissue disorders
   Congenital
   Fibrodysplasia ossificans progressiva Ehlers–Danlos syndrome Pseudoxanthoma elasticum Werner’s syndrome Acquired
   Calcium pyrophosphate deposition disease (CPPD) Hydroxyapatite deposition disease (HADD) Dermatomyositis Progressive systemic sclerosis (scleroderma) CREST syndrome (calcification, Raynaud’s phenomenon, oesophageal dysmotilpity, scleroderma, telangiectasia)
5. Miscellaneous
   Tumoral calcinosis Renal osteodystrophy Idiopathic calcinosis universalis Sarcoidosis with hypercalcaemia

Localized conditions
1. Soft tissue necrosis
Injection sites Thermal injuries (burns and frostbite)

2. Trauma
   Haematoma/subperiosteal Haematoma/cephalhaematoma Myositis ossificans Neurogenic heterotopic ossification
3. Tumours
   Benign
   Haemangioma (phleboliths) Lipoma Soft tissue chondroma Soft tissue aneurysmal bone cyst
   Malignant
   Synovial sarcoma Soft tissue osteosarcoma Soft tissue chondrosarcomah

Question 2

What are the ultrasound features of an abscess?

Answer 2

appear as predominantly cystic structures, often of a complex multiloculated nature. Posterior acoustic enhancement will be seen. The cyst contents can vary considerably in echogenicity depending on the nature of the collection and on the amount of soft tissue debris present, and may be shown to swirl around with gentle probe pressure. Although the collection itself will not show any Doppler signal, the tissues surrounding the collection may appear markedly hypervascular

Question 3

What is the grading system of muscle injuries?

Answer 3

grade 1 tear or strain represents microscopic tearing of muscle fibres, usually without loss of muscle strength. No macroscopic tear in the muscle fibres is seen, but oedema and haemorrhage may occur within the muscle. Appearances are usually normal on US although occasionally a mild increase in reflectivity can be seen

Grade 2 tears represent partial tears where there is macroscopic but incomplete separation of muscle or muscle and tendon. In these more severe muscle injuries the muscle belly will be retracted at the site of the tear, opening a gap which will be filled with haematoma or fluid

Grade 3 tears represent a full thickness tear of the muscle with complete separation of the torn ends of the muscle, or more commonly the muscle from the tendon

Question 4

What are the MRI findings of malignant Vs benign on soft tissue masses?

Answer 4

Homogeneous lesions on T1- and T2-weighted images tend to be benign, whereas malignant lesions are usually heterogeneous, particularly on T2-weighted images