No abstract

CRMO is a polymorphous disorder in which whole-body MRI is extremely useful for showing subclinical edema. Vertebral collapse requires long-term monitoring.

The thoracic outlet includes three compartments (the interscalene triangle, costoclavicular space, and retropectoralis minor space), which extend from the cervical spine and mediastinum to the lower border of the pectoralis minor muscle. Dynamically induced compression of the neural, arterial, or venous structures crossing these compartments leads to thoracic outlet syndrome (TOS). The diagnosis is based on the results of clinical evaluation, particularly if symptoms can be reproduced when various dynamic maneuvers, including elevation of the arm, are undertaken. However, clinical diagnosis is often difficult; thus, the use of imaging is required to demonstrate neurovascular compression and to determine the nature and location of the structure undergoing compression and the structure producing the compression. Cervical plain radiography should be performed first to assess for bone abnormalities and to narrow the differential diagnosis. Computed tomographic (CT) angiography or magnetic resonance (MR) imaging performed in association with postural maneuvers is helpful in analyzing the dynamically induced compression. B-mode and color duplex ultrasonography (US) are good supplementary tools for assessment of vessel compression in association with postural maneuvers, especially in cases with positive clinical features of TOS but negative features of TOS at CT and MR imaging. US may also allow analysis of the brachial plexus. However, MR imaging remains the method of choice when searching for neurologic compression.

Teaching points• Osseous involvement in children with LCH is very similar to that seen in multiple myeloma.• A solitary lytic lesion of the cranial vault is a typical radiographic finding of LCH.• A vertebra plana appearance in the spine is another typical radiographic finding.• Extensive signal intensity changes within bone marrow on MRI are a helpful sign for the diagnosis.• In long bones, endosteal scalloping may be responsible for a “budding appearance”.