title: Experimental muscle injury: correlation between ultrasound and histological findings.
abstract: BACKGROUND
  In this study we correlated ultrasound findings with histological changes taking place during experimentally induced degeneration-regeneration in rat skeletal muscle.
  
  
  METHODS
  Gastrocnemius muscles were injected with mepivacaine, and the progress of the muscle injury was monitored by ultrasound from day 1 to day 20. Muscles were extracted on the same days for histological examination.
  
  
  RESULTS
  The degenerative phase was characterized by increased echogenicity in the injured area; thereafter, echogenicity gradually diminished during the regenerative phase, attaining normal levels by 20 days postinjection. By this stage, histological examination revealed that regeneration was complete. The heteroechoic texture observed from day 4 to day 10 appeared to reflect the coexistence of degenerative and regenerative processes.
  
  
  CONCLUSIONS
  The results suggest that the degenerative and regenerative phases of muscle injury may be distinguished sonographically through differences in echogenicity and echotexture and, using Doppler ultrasound, differences in the degree of vascularization.
authors.affiliation: Laboratory of Performance and Sports Readaptation, Faculty of Sport Sciences, University of Castilla-La Mancha, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Jiménez-Díaz
authors.forename: Ignacio
authors.initials: I
authors.lastname: Jimena
authors.forename: Evelio
authors.initials: E
authors.lastname: Luque
authors.forename: Susana
authors.initials: S
authors.lastname: Mendizábal
authors.forename: Antonio
authors.initials: A
authors.lastname: Bouffard
authors.forename: Luis
authors.initials: L
authors.lastname: Jiménez-Reina
authors.forename: José
authors.initials: J
authors.lastname: Peña
mesh_terms: D000779:Anesthetics, Local / Q000009:adverse effects; D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D008619:Mepivacaine / Q000009:adverse effects; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D009135:Muscular Diseases / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology; D013997:Time Factors; D018608:Ultrasonography, Doppler
chemical_list: D000779:Anesthetics, Local; D008619:Mepivacaine