title: Case-control study to estimate the performance of dual-energy computed tomography for anterior cruciate ligament tears in patients with history of knee trauma.
abstract: OBJECTIVE
  Computed tomography (CT) is used to assess for fracture after knee trauma, but identification of ligamentous injuries may also be beneficial. Our purpose is to assess the potential of dual-energy computed tomography (DECT) for the detection of complete anterior cruciate ligament (ACL) disruption.
  
  
  METHODS
  Sixteen patients with unilateral traumatic ACL disruption (average of 58 days following trauma) confirmed by MRI, and 11 control patients without trauma, underwent DECT of both knees. For each knee, axial, sagittal, and oblique sagittal images (with DECT bone removal, single-energy (SE) bone removal, and DECT tendon-specific color mapping) were reconstructed. Four musculoskeletal radiologists randomly evaluated the 324 DECT reconstructed series (54 knees with 6 displays) separately, to assess for ACL disruption using a five-point scale (1 = definitely not torn, to 5 = definitely torn). ROC analysis was used to compare performance across readers and displays.
  
  
  RESULTS
  Sagittal oblique displays (mixed kV soft tissue, SE bone removal, and DECT bone removal) demonstrated higher areas under the curve for ACL disruption (AUC = 0.95, 0.93 and 0.95 respectively) without significant differences in performance between readers (p > 0.23). Inter-reader agreement was also better for these display methods (ICC range 0.62-0.69) compared with other techniques (ICC range 0.41-0.57). Mean sensitivity for ACL disruption was worst for DECT tendon-specific color map and axial images (24 % and 63 % respectively).
  
  
  CONCLUSIONS
  DECT knee images with oblique sagittal reconstructions using either mixed  kV or bone removal displays (either DECT or SE) depict ACL disruption in the subacute or chronic setting with reliable identification by musculoskeletal radiologists.
authors: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA, glazebrook.katrina@mayo.edu.
authors: Katrina N
authors: KN
authors: Glazebrook
authors: Lee J
authors: LJ
authors: Brewerton
authors: Shuai
authors: S
authors: Leng
authors: Rickey E
authors: RE
authors: Carter
authors: Peter C
authors: PC
authors: Rhee
authors: Naveen S
authors: NS
authors: Murthy
authors: B Mathew
authors: BM
authors: Howe
authors: Michael D
authors: MD
authors: Ringler
authors: Diane L
authors: DL
authors: Dahm
authors: Michael J
authors: MJ
authors: Stuart
authors: Cynthia H
authors: CH
authors: McCollough
authors: J G
authors: JG
authors: Fletcher
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging*; D000070598:Anterior Cruciate Ligament Injuries; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging*; D022125:Lacerations / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012422:Rupture, Spontaneous / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult