were remarkable for a leukocytosis of 16,000 per mm3 (81 polymorphonuclear leukocytes, 16 lymphocytes, 3 basophils), an erythrocyte sedimentation rate of 86 mm/hr (normal <12 mm/hr), and serum uric acid of 13.4 mg/dl (normal: 4—8 mg/ dl). Aspiration ofthe right knee yielded 30 cc of serosanguin eous fluid with 52,000 leukocytes per mm3 (93 polymorpho nuclear leukocytes, 5 monocytes, 1 lymphocyte, 1 eosinophil) as well as sheets of urate crystals. Gram stain of the aspirate was negative. Cultures of the aspirate were reported as no growth. The diagnosis of polyarticular acute gouty arthritis was made, and intravenous (i.v.) colchicine therapy was be gun. On the second day after admission, the patient became febrile to 39°C, and his leukocyte count rose to 23,000 per mm3. An ‘ ‘ ‘In-labeled leukocyte study was requested to cx dude superimposed infection. Twenty-four hours postinjection of 18.5 MBq (500 @iCi) of autologous white cells labeled with @ ‘In-oxine according to the method of Thakur et al. (1), whole-body imaging was performed on a large field of view gamma camera, equipped with a medium-energy collimator. Energy discrimination was accomplished by 20% windows centered over the 174- and 247-keVphotopeaks of―‘In. Intense accumulation of labeled white cells was seen in both knees, ankles, and both first metatarsophalangeal joints, corresponding to the joints al'. fectedby acute gouty arthritis (Fig. 1). Blood and urine cultures performed at the same time were subsequently reported as no growth, and the patient was treated with i.v. ACTH and colchicine. Over the next 10 days he defervesced, his leukocyte count returned to normal, and there was marked clinical improvement as the acute attack subsided; minimal bilateral knee pain did persist however. Indium-i 11-leukocyte imaging repeated 12 days after the initial study revealed faint uptake in both knees, concordant with the clinical impression of resolving acute gouty arthritis (Fig. 2). DISCUSSION Gouty arthritis is a complication ofprolonged hyper uricemia; acutely it is characterized by recurrent epi sodes of severe joint inflammation which, if untreated, progress to tophaceous gout with joint deformities and disabilities, renal calculus formation and eventually, renal failure (2). The initial presentation ofacute gouty arthritis is usually monoarticular, and typically involves the lower extremities, especially the first metatarsopha langeal joints, the ankles, and the knees. Involvement ofthehips, spineandupperextremitiesisuncommon(3). Indium-i 11-labeled leukocyte scintigraphy was performed on a 66-yr-old male with polyarticular acute gouty arthritis. Images revealed intense labeled leukocyte accumulation in a pattern indistinguishable from septic arthritis, in both knees and ankles, and the metatarsophalangeal joint of both great toes, all of which were involved in the acute gouty attack. Joint aspirate as well as blood cultures were reported as no growth; the patient was treated with intra venous coichicine and ACTH for 10 days with dramatic improvement noted. Labeled leukocyte imaging, repeated 12 days after the initialstudy, revealed near total resolution ofjoint abnormalities, concordant with the patient's dinical improvement. This case demonstrates that while acute gouty arthritis is a potential pitfall in labeled leukocyte imaging, inthepresenceofknowngout,itmayprovidea simple, objective, noninvasivemethod ofevaluating patient response to therapy. JNucIMed 1990;31:682—687 ndium-1 11- (‘ ‘ ‘In) labeled leukocyte scintigraphy is a useful radionuclide procedure for the diagnostic eval uation of musculoskeletal sepsis. In order to maximize the utility of this procedure, individuals interpreting labeled leukocyte imaging must be aware of potential pitfalls that affect the sensitivity or specificity of the procedure. The following report presents the results of labeled leukocyte imaging in a case of acute gouty arthritis: as a potential pitfall, as well as a method of monitoring patient response to therapy. CASE REPORT A 66-yr-old male was admitted to our institution with a chief complaint of severe, polyarticular pain of six days du ration. Physical examination of the patient revealed marked erythema, swelling and tenderness of both knees and ankles, as well as the metatarsophalangeal joint of both great toes. Radiographs of the knees were normal. Laboratory values ReCeivedSept. 1, 1989;revisionaccepted Dec.8, 1989. For repiints contact: Christopher J. Palestro, MD, Mt. Sinai Medical Center, PhySicS-NUclear Medicine,Box 1141, One Gustave L.LevyPlace, New York,NY 10029. 682 The Journal of Nuclear Medicine • Vol. 31 • No. 5 • May1990 Appearance of Acute Gouty Arthritis on Indium-i 11-Labeled Leukocyte Scintigraphy Christopher J. Palestro, Amarilis Vega, Chun K. Kim, Alfred J. Swyer, and Stanley J. Goldsmith Andre Meyer Department ofPhysics-Nuclear Medicine, Mt. Sinai School ofMedicine, Mt. Sinai Medical Center, New York, New York