Musculo-skeletal   [back to the Category]

X-Rays, Scintigraphy, Scanner, MRI and Echographia   [read the french version]

Author :   Docteur Anne Thiescé

X-Rays, Scintigraphy, Scanner, MRI and Echographia

X-RAYS

Radiography allows us to visualize bones and calcifications. Fig 1: X-ray of L3 lysis.
It shows bone anomalies:
- holes in the bone (cysts, tumours, hyper-pressure geodes in arthrosis),
- solutions of bone continuity for fractures,
- bone condensations (tumours, sub-chondral bone condensations in arthrosic conditions),
- bone constructions (periosteum spissitude found in periostitis, bone calluses in consolidated fractures, lipping of vertebrae in arthrosis).

X-rays show concealed indications such as the diminution of space between osseus parts (articular joint pinching in arthrosis, discal collapse in spinal pathology).

X-rays also show tendon calcification, tendinopathy and osteoma soft tissue ossification.

Dynamic X-rays allow us to see the behaviour of an articulation in wide articular amplitude, and to visualize the loss of articular surface parallelism, as, for example, in sprains.

Radiography with intra-articular injection or arthrography: makes the intra-articular cavity opaque and prominently displays articular cartilage fissuring, injuries to intra-articular structures such as meniscal injuries or ligamentary ruptures. Fig 2: Arthrography.

SCINTIGRAPHY

Scintigraphy is a painless examination that takes about two and a half hours. A radioactive product (technetium-99m pyrophosphate) is injected which specifically fixes itself on developing osseus tissue. The radiation is recorded using a camera, the radiation sustained is negligible.
The hyper-fixation zones show active and recent bone injuries such as fractures, periostitis as well as bone tumours, infections and inflammations. Fig 3: Scintigraphy of L3 lysis.

SCANNER

The scanner is a painless examination that takes about 20mins. It is a special radiological process that combines X-rays and a computer. The scanner allows a very precise axial section study, of a given area. The scanner can be combined with intravenous or intra-articular injections.
The scanner can only be a second intention examination, it does not give an overall view of the area and certain structures of soft pathologies are badly differentiated. Fig 4: Scan of L3 lysis.

M.R.I.

Magnetic Resonance Imaging is also a painless examination that takes about 50mins. The principle of M.R.I. is to detect electromagnetic waves given off by certain atoms in the human body. The signal received by the computer reconstructs a sectioned image and visualizes the intensity of the signal. It is a radiation-free examination that requires the patient's co-operation – he must remain totally immobile, in blocks of approx. 5mins, for the length of time it takes to obtain the image.

M.R.I. allows a more comprehensive view than the scanner since it gives section images in 3D, but it is usually less efficient for bone injuries.

ECHOGRAPHIA

Echographia gives off ultrasounds which are reflected differently according to the structures encountered (cartilage, bone, muscles and liquid). There is no radiation. The examination takes about 15mins.

Echographia gives fairly accurate images of soft parts (tendons, effusion, haematoma) of the human body.