title: Diagnostic value of the radiographic muscle-to-bone thickness ratio between the pronator quadratus and the distal radius at the same level in undisplaced distal forearm fracture.
abstract: OBJECTIVE
  To investigate the value of the muscle-to-bone ratio (MBR), which is the ratio between the maximum pronator quadratus thickness (mPQT) and the distal radial thickness (DRT) at the same level, in comparison with mPQT in the diagnosis of undisplaced fractures in distal forearm (FDF) on radiographs.
  
  
  METHODS
  This study was conducted with 210 wrists of 210 volunteers (79 male, 131 female) and 106 wrists of 106 patients with acute undisplaced FDF (53 male, 53 female). The mPQT was measured on lateral radiographs, and the MBR was calculated for each wrist.
  
  
  RESULTS
  The mean mPQT (7.37 ± 1.99 mm) and MBR (0.55 ± 0.15) in the fracture group were significantly larger than those (4.70 ± 1.42 mm and 0.31 ± 0.09) in the control group respectively (all P<0.05). Sexual differences of mPQT were found in both control and fracture groups (all P<0.05). There were no gender differences of MBR in either control or fracture group (all P>0.05). ROC analysis revealed that the discriminating efficacy of MBR was significantly superior to that of mPQT (P<0.01). The most optimal diagnostic discrimination was obtained by a MBR cut-off value of 0.4.
  
  
  CONCLUSIONS
  The MBR can be used as a new index for the diagnosis of undisplaced FDF, as well as a complementary means to detect occult fractures. If the MBR is larger than 0.4 in a patient with suspected or occult FDF, a further MRI examination will be justifiably needed.
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China; Research Center for Sectional and Imaging Anatomy, Shandong University School of Medicine, Jinan 250012, Shandong, PR China; Shandong Key Laboratory of Advanced Medical Imaging Technologies and Application, Jinan 250012, Shandong, PR China. Electronic address: sunboy4554@163.com.
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China. Electronic address: lustar1976@163.com.
authors.forename: Dianxing
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China. Electronic address: gwx9899@163.com.
authors.forename: Wuxian
authors.initials: W
authors.lastname: Gong
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China. Electronic address: hst996@163.com.
authors.forename: Shiting
authors.initials: S
authors.lastname: Huang
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China. Electronic address: leilei_5143@163.com.
authors.forename: Qinhua
authors.initials: Q
authors.lastname: Luan
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China. Electronic address: yangjin_527@163.com.
authors.forename: Jinyong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Shandong Provincial Hospital Affiliated to Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China. Electronic address: wangd2013@163.com.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, 324 Jing Wu Road, Jinan 250021, Shandong, PR China. Electronic address: tian_jun1@126.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001837:Body Weights and Measures / Q000379:methods*; D005260:Female; D005542:Forearm / Q000000981:diagnostic imaging; D005543:Forearm Injuries / Q000000981:diagnostic imaging*; D005596:Fractures, Closed / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D011859:Radiography; D011884:Radius / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D014953:Wrist / Q000000981:diagnostic imaging; D055815:Young Adult
keywords: Muscle-to-bone ratio; Pronator quadratus; Radiograph; Undisplaced distal forearm fracture