Mandatory medical device diagnostics.
- X-ray examination of the affected joint (should always be done on both sides) – is not only used for the current diagnosis, but is mainly part of the follow-up of a gout patient. The signs of gout develop slowly and often painlessly, so the X-ray examination may be perfectly normal at the first attack. On the other hand, clear gout-typical changes in the affected joint and in the opposite or other joints may already be evident during the first gout attack. During the first gout attack, X-ray imaging of the feet, hands and knee joints is recommended. Notice. Because uric acid crystals are not visible radiologically, only indirect evidence of gouty tophi (reactive change in the context of gout; it is nodular thickening of cartilaginous tissue inside or near affected joints) can be seen on x-ray – such as usures (wear and tear; atrophy of bones), cysts, calcifications, and osteoplastic reactions of the periosteum (thin layer of tissue covering the outer surface of all bones).
- Renal sonography (ultrasound examination of the kidneys) including the urinary tract – to detect kidney stones or renal parenchymal damage.
Optional medical device diagnostics – depending on the results of the history, physical examination, laboratory diagnostics and obligatory medical device diagnostics – for differential diagnostic clarification.
- Soft tissue sonography – allows detection of the extent of a gouty tophus and its differentiation from cystic processes or rheumatoid nodules. Sodium urattophi present as solid, mixed low-echo to high-echo nodules sometimes with acoustic shadowing, whereas rheumatoid nodules are generally low-echo and without acoustic shadowing.
- Arthrosonography (ultrasonography of joints) – can provide information about joint effusion and possible ligamentous rupture [hyperechogenic synovial fluid with “blizzard” aspect; double contour signs on articular cartilage, deposition of tophi, bony erosions, and signs of synovitis/inflammation of synovial membrane ]
- Abdominal sonography (ultrasound examination of the abdominal organs) – liver parenchymal damage and/or chronic pancreatitis (inflammation of the pancreas) indicate an existing alcohol problem; if malignancy (malignancy) is suspected as a possible cause of hyperuricemia, sonographic examination of the abdomen (abdominal organs) serves to find a tumor.
- Urography – imaging of the urinary tract to exclude uric acid stones.
- Polarized microscopic examination of the joint punctate.
- Dual-energy computed tomography (DECT); radiological procedure that can display characteristic imaging properties of uric acid depots by using two energetically different X-ray tubes and special image processing – for the detection of uric acid deposition [sensitivity (percentage of diseased patients in whom the disease is detected by the application of the procedure, i.e., a positive finding occurs) 87%; specificity (probability that actually healthy persons who do not suffer from the disease in question are also detected as healthy in the test) 84%]
