title: CT of sclerotic bone lesions: imaging features differentiating tuberous sclerosis complex with lymphangioleiomyomatosis from sporadic lymphangioleiomymatosis.
abstract: OBJECTIVE
  To determine if sclerotic bone lesions evident at body computed tomography (CT) are of value as a diagnostic criterion of tuberous sclerosis complex (TSC) and in the differentiation of TSC with lymphangioleiomyomatosis (LAM) from sporadic LAM.
  
  
  METHODS
  Informed consent was signed by all patients in this HIPAA-compliant study approved by the institutional review board. Retrospective analysis was performed of the body CT studies of 472 patients: 365 with sporadic LAM, 82 with TSC/LAM, and 25 with TSC. The images were reviewed by using a picture archiving and communication system workstation with bone settings (window width, 1500 HU; window level, 300 HU) and fit-to-screen option. CT image characteristics assessed included shape, size, and distribution of sclerotic bone lesions with subsequent calculation of differences in the frequency of these lesions.
  
  
  RESULTS
  Most commonly the sclerotic bone lesions were round, measured 0.3 cm (range, 0.2-3.2), and were distributed throughout the spine. The frequencies differed among the three patient groups Four or more sclerotic bone lesions were detected in all 25 (100%) of those with TSC, with a sensitivity of .89 (72 of 82) and specificity of .97 (355 of 367) in the differentiation of sporadic LAM from TSC/LAM (P < .01).
  
  
  CONCLUSIONS
  The number of sclerotic bone lesions at body CT is of potential value in the diagnosis of TSC and in the differentiation of patients with sporadic LAM from those with TSC/LAM. (c) RSNA, 2010.
authors.affiliation: Radiology Service, Washington D.C. Veterans Affairs Medical Center, 50 Irving St NW, Room BH-223, Washington, DC 20422, USA. nilo.avila@va.gov
authors.forename: Nilo A
authors.initials: NA
authors.lastname: Avila
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Dwyer
authors.forename: Antoinette
authors.initials: A
authors.lastname: Rabel
authors.forename: Thomas
authors.initials: T
authors.lastname: Darling
authors.forename: Chien-Hui
authors.initials: CH
authors.lastname: Hong
authors.forename: Joel
authors.initials: J
authors.lastname: Moss
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D018192:Lymphangioleiomyomatosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014402:Tuberous Sclerosis / Q000000981:diagnostic imaging*