![]() ![]() ![]() The appearance of synovitis may be very different on B-mode ultrasound, changing from a hypoechoic to isoechoic pattern and progressing to a hyperechoic pattern. The amount of perfusion seen is very minimal compared with that seen in arthritis patients, but it shows that Doppler activity does not always equal inflammation. If the ultrasound unit has a very sensitive Doppler system, it may be possible to see flow even in normal joints-most frequently in the wrist joint, seldom in the metacarpophalangeal joints, and almost never in the proximal interphalangeal joints. Studies have shown that joints should be examined in the neutral position because full flexion or extension appears to minimize the Doppler activity. It may be related to the positioning of the shoulder during examination, because the investigated structures often can be seen only in extension (meaning strain on tendons and capsule), which may compromise the perfusion. The shoulder also shows less Doppler activity compared with similar superficial joints. The Doppler image is more sensitive to attenuation due to depth than the gray-scale image. The carpus (C) is partially shown.Īll joints may show Doppler activity when inflamed, but the hip joint rarely shows Doppler activity because of the deep location of the joint. The ulnar part of the wrist joint has synovial hypertrophy (stars) and shows Doppler activity, especially around the head of the ulna (U). With Doppler ultrasound, it is possible to see various degrees of perfusion, and as with synovial hypertrophy, it may be of interest to grade the degree of perfusion as a way of measuring changes in perfusion during treatment. The Doppler data provide information about perfusion ( Fig. That information is transformed by the ultrasound machine to color information displayed as the color pixels in the image. When the ultrasound beams are reflected by objects in motion (i.e., red blood cells), they change frequency, and the difference between the emitted frequency and the received frequency is called the Doppler shift ( Fig. When the transducer is held still and the patient is immobile, the only thing moving in the image plane is blood. Power Doppler and color Doppler are used, and in both cases, color information is superimposed on the gray-scale image. It aids the diagnosis of inflammatory activity in a joint (i.e., synovitis) that can be associated with the abnormal production of fluid. Studies have even shown that ultrasound is superior to clinical assessment of joint swelling and tenderness.ĭoppler ultrasound can be used to visualize a perfusion in the inflamed synovium. Ultrasound can be used to detect and diagnose synovitis and synovial hypertrophy. Synovitis is the term for synovial hypertrophy and hyperemia as demonstrated by Doppler activity. Synovial hypertrophy is swelling of the synovial lining, but the definition does not state whether there is hyperemia. It is important to maintain correct terminology. In the OMERACT definition, Doppler activity is not necessary to diagnose synovitis, taking into account that not all ultrasound equipment has a sensitive enough Doppler system to differentiate between inactive disease and active disease. ![]() The definition for synovitis is very broad, confirming that synovial hypertrophy is an abnormal intra-articular tissue that is nondisplaceable and poorly compressible. Anechoic fluid (stars) and echo-rich synovial hypertrophy (plus sign) can be seen. In the fossa olecrani in the elbow, synovial fluid pushes the capsule (arrowhead) upward. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |