Musculoskeletal ultrasonography in rheumatic diseases

Abstract

Ultrasonography is an imaging technique based on sound waves used for the evaluation of soft tissues. Sound waves have been used for a long time in nonmedical fields, including military defense systems, radar systems, and detection of icebergs. Technological advances resulted in new techniques becoming available for medical imaging, including ultrasonography, magnetic resonance imaging, and computed tomography. Nowadays, the use of imaging has become a gold standard protocol in the diagnosis of many diseases, and recently developed diagnosis and therapy options provide more efficient treatment of rheumatic diseases. Thus, it has become possible to prevent structural damage and disability in patients with rheumatic disease. Musculoskeletal ultrasonography is becoming a preferred imaging technique for rheumatic diseases, as it has many advantages. Among its advantages are being inexpensive, being radiation-free, having a dynamic image capacity, helping to detect disease activity, and helping with early detection and diagnosis of structural damage. This review summarizes the use of ultrasonography in rheumatic diseases.

Keywords: Musculoskeletal ultrasonography; crystal arthritis; rheumatoid arthritis; spondyloarthropathies.

Figure 1

An anechoic effusion in the second MCP joint in an RA patient (a), and fluid disappearing when pressure is applied to the skin with a US probe (b). The stars indicate synovial fluid, “mkp” is the metacarpophalangeal joint, and “phalanks” is phalanx.

Figure 2

The joint fluid has disappeared with compression (a), but the synovial tissue is not displaced and has a hypoechoic appearance (b). The stars indicate synovial fluid, and the arrow is a synovial hypertrophy.

Figure 3

Thickening of the tendon and a hypoechoic appearance at the Achilles attachment site, with calcaneal erosion and increased Doppler activity involving the retrocalcaneal area. The star indicates the calcaneal erosion.

Figure 4

Tenosynovitis image of an RA patient at wrist level shows active (grade 3) tenosynovitis with both axial and longitudinal gray (a) and Doppler scales (b). Stars indicate synovial fluid.

Figure 5

Erosion in the 5th MTP foot joint of an early RA patient. There is cortical continuity deterioration in two planes (a: longitudinal; b: transversal scans). The arrows indicate erosion.

Figure 6

US image of a 42-year-old patient with complaints of pain and swelling in the knee and diagnosed with prepatellar bursitis. The hypoechoic line is below the patella, and the bursa containing anechoic fluid material is above the patella. The star indicates synovial fluid.

Figure 7

US image of the wrist of a 36-year-old patient with a 5-year diagnosis of RA, with no joint sensitivity or swelling, and using methotrexate 20 mg/week and hydroxychloroquine 200 mg/day. Sedimentation rate is 2 mm/s, CRP is 0.1 mg/dL, DAS is 28, ESR is 0.49, SDAI is 2, and CDAI is 2. Gray scale (a) shows fluid in the joint space, and there is a weak Doppler signal on the wrist (b). This patient is in remission clinically but not sonographically. The stars indicate synovial fluid.

Figure 8

MSU crystals deposited on the cartilage surface: distal femur cartilage (a), talus cartilage (b), active gout arthritis, positive Doppler signal (c), and double contours seen in the 1st MTP joint in a gout patient (d). Arrowheads indicate double contours, and asterisks indicate a snowstorm.

Figure 9

Calcium pyrophosphate dihydrate crystals accumulated in the hyaline and fibrocartilage in the knee joint. Unlike in gout, these crystals accumulate mostly inside the cartilage. The star indicates cartilage, the arrows show calcium pyrophosphate dihydrate crystals, qt: Qudriceps tendon and b is the distal femur bone.

Figure 10

Gray scale (a) and Doppler scale (b) US performed on a shoulder with PMR diagnosis, the patient has edema and an anechoic effusion area around the shoulder with a thickened biceps tendon in both planes (axial and longitudinal). Stars indicate synovial hypertrophy, and bt shows the biceps tendon.

Figure 11

Sonographic findings in knees with OA include osteophytes (white arrowheads), suprapatellar effusion (e), protrusion of the medial meniscus (mm) with displacement of the medial collateral ligament, a Baker’s cyst (star), and decreased cartilage (c) thickness (arrow).

Figure 12

Wrist injection in RA patients (a). The arrowheads show the needle, r is the radius, s is the scaphoid, et is extensor tendon, the stars indicate synovial fluid, and the arrow in (b) shows the postinjection steroid crystal deposits.