Whole-body CT characteristics of patients with severe fever with thrombocytopenia syndrome.

purposeTo characterize the computed tomography (CT) features of severe fever with thrombocytopenia syndrome (SFTS) and to identify imaging features predictive of an adverse prognosis. MATERIALS AND

methodsThirty-one patients diagnosed with SFTS between July 2017 and August 2025 and who underwent whole-body CT (17 men, 14 women; mean age, 75.3 years; 24 survivors, 7 non-survivors) were retrospectively reviewed. CT findings of the chest, abdominal organs, and regional lymph nodes were assessed. Initial CT scans (n = 31) were obtained a mean of 3.8 days (range, 0-7) after symptom onset, and follow-up CT scans (n = 20) were performed in 17 patients a mean of 6.0 days (range 1-18) after the initial scan, giving a total of 51 examinations. Additionally, for three cases in which autopsy was performed, correlation analysis was performed between the CT findings and pathological findings.

resultsOn initial CT, the most frequent finding was regional lymphadenopathy (n = 30, 96.8%), most commonly involving inguinal (n = 17, 54.8%) and axillary nodes (n = 11, 35.5%). Perinodal fat stranding was observed in 29 patients (93.5%). The most common thoracic finding was ground-glass opacity (GGO) (n = 17, 54.8%), followed by bronchial wall thickening (n = 16, 51.6%) and interlobular septal thickening (n = 15, 48.4%). Among abdominal organs, splenomegaly was the most frequent finding (n = 25, 80.6%), followed by renal enlargement (n = 15, 48.4%). On follow-up CT, the most frequently observed changes compared with the initial CT were increased renal volume (n = 17, 85%) and increased hepatic volume (n = 14, 70%). GGO was significantly more frequent in non-survivors than in survivors.

conclusionsCharacteristic CT findings of SFTS include regional lymphadenopathy with perinodal fat stranding, followed by splenomegaly and GGO. GGO may be an imaging finding predictive of an adverse prognosis.