E³ 719 - Spine: osseous lesions
1. To establish a structured indication basing on clearly pre-defined questions.
2. To understand the distinct patterns of osseous spine lesions on projection radiographs and MRI.
Osseous lesions of the vertebra, mainly manifesting as signal alterations of the bone marrow, are challenging because of the sometimes only subtle differences among these entities. Indications drive the proper work-up especially in these situations: Spondylarthropathies may be suspected clinically with a sensitivity of more than 70 percent. Skeletal metastasis, plasmocytoma and primary bone tumours are in many cases part of a step-wise oncologic workup. Bone marrow hyperplasia can be better differentiated from hematopoetic diseases better when knowing the life-style parameters. The red-flags concept has only in part been proven helpful and may be replaced by more sophisticated questionnaires. The investigation with projection radiography and MRI should include in many of these cases the whole-spine. In rheumatic and infectious inflammatory diseases the sacrum and the sacroiliac joints must be included. The interpretation of focal spinal lesions relies on the differentiation of osteolytic or sclerotic bone lesions. Pitfalls may be avoided by exactly differentiating the localisation within the vertebra and the patterns of bone marrow edema. Tricky lesions are atypical hemangioma, metastasis with a mixed pattern, lytic-expansile fibrous dysplasia and SAPHO. Diffuse spinal abnormalities mainly manifest as osteoporotic on projection radiographs or bone marrow changes with MRI. Diffuse haematopoetic marrow hyperplasia may be due to chronic anaemia, infection, chemotherapy, adiposity in females, heavy smoking and long-distance running. In conclusion, the diagnostic workup of osseous spinal lesions, mainly the indications for imaging, has changed and is continuously changing.
1. To learn how to use MR parameters to suggest a specific diagnosis.
2. To learn how to use radiographic and clinical parameters to suggest a specific diagnosis.
3. To identify the new types of spinal tumours and their radiological features.
Metastases and myeloma are much more frequent than primary tumours of the spine. Only mature haemangiomas and enostosis are frequent asymptomatic incidental findings in the spine. In patients younger than 30 years, primary osseous tumours do occur with an incidence of <5% of primary osseous tumours, and may present with pain, associated scoliosis, or neurological symptoms. Most of these, with the exception of Ewing sarcoma (and its metastases) and osteosarcoma are benign and include osteoid osteoma, osteoblastoma, ABC, Langerhans cell histiocytosis, giant cell tumour, and vascular haemangiomas. These aforementioned tumours constitute 80% of all primary osseous tumours in the spine. In patients >30 years, some of these benign conditions are also seen (giant cell tumour), but malignant tumours (chordoma, lymphoma) are becoming more frequent. Benign lesions that are increasingly diagnosed and have specific features are hibernoma and benign notochord tumour. Normally primary osseous tumours of the spine can be differentiated using radiologic criteria from metastases and infection. Radiological features used in diagnosis that will be discussed include location in the spine (sacrum: chordoma, GCT. Location in posterior elements: osteid osteoma, osteoblastoma, osteochondroma), MR signal intensity (low SI in GCT), presence of marked reactive changes (osteoid osteoma, osteoblastoma, Langerhans cell histiocytosis, chondroblastoma), CT density, morphology, way of extending into nearby anatomical structures.
1. To discuss the advantages and disadvantages of MR, CT, and PET/CT in diagnosis.
2. To identify MR features in multiple myeloma and metastasis.
3. To know the imaging role in treatment planning and monitoring therapy of metastases and myeloma.
Multiple myeloma represents a malignant bone marrow neoplasia in which a monoclonal strain of atypical plasma cells proliferate. Due to various therapeutical options and due to the large variance in survival, the sensitive detection of myeloma involvement of the skeleton is mandatory to enable for an accurate staging. In MRI, 5 different infiltration patterns can be found. The most sensitive imaging method for multiple myeloma is MRI. Whole body MRI is superior to conventional skeletal survey and whole body MDCT. On the other hand, MDCT is the method of choice for displaying osteolysis and determining the fracture risk. Durie and Salmon staging system created in 1975 is the most widely used clinical staging system. It combines laboratory and imaging data (x-rays). In 2003, the Durie and Salmon PLUS staging system has been released, which includes whole body MRI and or PET-CT data. Bone metastases are the most common secondary bone tumours of the spine. CT can clearly demonstrate tumour matrix and the extent of osseous destructions. The radiologist should give a fracture risk assessment. MRI is the most sensitive method for metastasis detection by showing directly bone marrow involvement. Different pseudotumours and bone marrow lesions and variations can mimic metastases. Sometimes malignant collapse of a vertebra is the first sign of a malignancy. It is of clinical importance to differentiate it from an acute benign osteoporotic vertebral collapse. Morphologic as well as special sequences, such as DWI, can help in finding the correct diagnosis.