When diagnosing arthritic psoriasis, imaging tests are required, including X-ray, MRI and ultrasound. What exactly do the different tests do, what do you pay attention to during the tests and what are the abnormal results? After reading the following introduction, you will understand.
1.X-ray examination: what needs to be done, how to do it, precautions, and how to interpret abnormal results
Psoriasis patients with repeated skin damage will have symptoms such as swelling and soreness of the joints of the limbs, and joint invasion may occur, causing arthritic psoriasis, at which time X-ray examination is needed to clarify the presence of arthropathy, and X-ray examination can provide the corresponding imaging basis.
X-ray examination of joints
Specific operation method: Using a DR camera, routine postural X-ray examination is performed on the bilateral wrist, ankle and knee joints of the patient being followed, and then two experienced imaging physicians analyze and diagnose the patient’s clinical data and symptoms, and summarize the X-ray manifestations of arthritic psoriasis.
During the examination, there are cautions.
– X-ray examinations to a certain extent can cause radiation to the human body. When children undergo X-ray examinations, the perineum should be covered so as not to cause harm to the gonads.
– Pregnant or pregnant women should minimize X-ray examinations to avoid affecting egg quality and fetal development
– Metal objects such as earrings and necklaces should be removed during the examination.
In the examination results, if the distal interphalangeal joints show signs such as swelling of the surrounding soft tissues, fluid in the joint cavity, osteoporosis, bone erosion and osteophytes at the edges and central part of the joints, and narrowing of the joint space, it can be used as a characteristic X-ray performance for diagnosing arthritic psoriasis.
2.MRI examination: what to do, how to do it, precautions, and how to interpret abnormal results
Magnetic resonance imaging (MRI) can display images of joints in multiple directions, with high resolution of tissues, and can clearly show the signal changes of joint capsule, joint cavity, joint cartilage, ligaments, tendons, synovium and surrounding soft tissues, so when symptoms of joint swelling and dysfunction occur, arthritic psoriasis can be diagnosed through MRI.
Magnetic resonance imaging
Specific procedure: Using an MRI instrument, acquisition techniques include T1-weighted and T2-weighted imaging, inversion recovery sequences, compression lipid sequences, and other acquisition sequences. The soft tissues around the ankle joint are observed for abnormalities, tendons for lesions, bony joint surfaces for smoothness, bone destruction, joint cavity for effusion and bone marrow for abnormalities.
During the examination, there are some precautions that need to be known in advance.
– Metal objects carried on the body, such as metal jewelry, metal accessories, or cell phones, lighters, dentures, glasses, etc., should be removed before the examination.
– If there are metal implants (such as pacemakers, artificial valves, metal clips, metal birth control rings, etc.) in the body, you should inform the doctor in time, and the doctor will see if the MRI can be done according to the patient’s specific situation.
Among the examination results, bone marrow edema, tendon swelling and soft tissue edema around the tendon sheath are the early manifestations of arthritic psoriasis, and bone destruction, joint subluxation or osteophytes are the late manifestations of arthritic psoriasis, and bone erosion is manifested as interruption of bone cortex continuity.
3.Ultrasound examination: what needs to be done, how to do it, precautions, and how to interpret abnormal results
Ultrasonography can detect early characteristic manifestations of arthritic psoriasis, such as bursitis, inflammation of tendons or ligament ends, etc., with specificity.
With the continuous development and innovation of ultrasound technology, ultrasound technology has been more and more widely used in the diagnosis of bone and joint-related diseases, especially in the diagnosis of arthritic psoriasis, which has made breakthrough progress.
Ultrasound examination of joints
The specific operation method: the patient bends the knee, the sole of the foot naturally steps on the examination bed, relaxes the ankle joint, and scans the ankle joint from outside to inside with a color Doppler ultrasound diagnostic instrument or high-frequency ultrasound instrument to observe whether there is any abnormality on the bone surface, whether there is fluid in the joint cavity, whether there is thickening of tendons and tenosynovitis, whether there is swelling of the soft tissue around the joint, whether the joint surface is smooth and whether there is synovial hyperplasia. The ankle joint is then placed in the prone position, with the ankle on the edge of the examination bed and the toes naturally dropping, and the back of the ankle joint is scanned and abnormal sound images are recorded.
There are no special precautions for the ultrasound examination of arthritic psoriasis. Wear loose clothing before the examination to facilitate exposure of the examination area. Try to cooperate with the doctor during the examination to avoid violent injuries.
Psoriasis with joint damage may be indicated if the following abnormal findings are present in the examination results.
– The main findings of high-frequency ultrasound include diffuse subcutaneous soft tissue swelling, joint cavity effusion, bursal lesions, synovial thickening, hypoechoic tendon and ligament ends, and flexor tenosynovitis.
– Doppler ultrasound mainly shows increased blood flow signal, vascular erosion of tendon ligaments, cartilage changes and disruption of bony cortical continuity.
References
[1]Wang Jing,Pang Lina,Song Hongping. A comparative study of ultrasound, X-ray and MRI in detecting ankle lesions in psoriatic arthritis [J]. Journal of Clinical Ultrasound Medicine,2018,20(01):19-21.
[2]Liu Y,Li Shasha,Wu Xiaosong,Yin Jiancheng,Jin Weijun,Zhang Zhidong. Nuclear magnetic resonance-based plasma metabolomics in patients with common psoriasis[J]. Journal of the Second Military Medical University,2017,38(01):74-80.
[3]Zhang Lei,Liu Meihan,Wang Linlin,Wei Jiahui. The significance of ultrasound technology and MRI in psoriatic arthritis[J]. Chinese Experimental Diagnostics,2016,20(09):1554-1555.
[4]Ren P,Wang T,Chen L.G. Research progress in the application of MRI in psoriatic arthritis[J]. Journal of Medical Imaging,2013,23(08):1314-1316.