case_images: PMC7517663_01
case_images: Swelling and redness are seen at the wrist (a). Plain radiography shows an osteolytic lesion in the distal radius with soft tissue swelling (b). Magnetic resonance imaging shows low signal intensity on T1-weighted
  imaging (c) and high signal intensity on T2-weighted, fat-suppressed
  imaging (d) in both the osteolytic area and the surrounding bone marrow. A fluid collection is seen (e - top image, T1-weighted imaging; e - bottom image,
  T2-weighted imaging). Yellow arrows point to a rim of high signal intensity on T1-weighted imaging ("penumbra sign") (c, e - top image).
case_images: jbji-6-1-g01.jpg
case_images: PMC7517663_01_jbji-6-1-g01.jpg
case_images: Ch1.F1
case_images: On physical examination at our hospital, her wrist was swollen and the overlying skin was reddish and taut (Fig. 1a). Plain radiography revealed an ill-defined osteolytic lesion in the radius (Fig. 1b). The presence of a fluid collection in the soft tissue anterior to the distal radius, with low signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging, suggested an abscess (Fig. 1c-e). The diagnosis based on imaging findings was osteomyelitis.
case_images: One year after treatment, the previously osteolytic area is
  ossified (a). The lesion has homogenous, low signal intensity on T1-weighted
  imaging (b) and homogenous, high signal intensity on T2-weighted,
  fat-suppressed imaging (c). No fluid collection is present (d - top image,
  T1-weighted imaging; d - bottom image, T2-weighted imaging). Two years after treatment, no recurrence is seen (e).
case_images: jbji-6-1-g02.jpg
case_images: PMC7517663_01_jbji-6-1-g02.jpg
case_images: Ch1.F2
case_images: The osteolytic area became ossified, as seen on plain radiography performed 1 year after treatment (Fig. 2a). T2-weighted imaging, without any abnormal signal indicating edema of the bone marrow. The fluid collection had resolved (Fig. 2b-d). There was no recurrent infection observed 24 months after completing antibiotic therapy (Fig. 2e).