title: [Contrast-enhanced Ultrasound in Diagnostic Imaging of Muscle Injuries: Perfusion Imaging in the Early Arterial Phase].
abstract: BACKGROUND
  Ultrasound is a standard procedure widely used in the diagnostic investigation of muscle injuries and widely described in the literature. Its advantages include rapid availability, cost effectiveness and the possibility to perform a real-time dynamic examination with the highest possible spatial resolution. In the diagnostic work-up of minor lesions (muscle stiffness, muscle strain), plain ultrasound has so far been inferior to MRI. The case presented by us is an example of the possibilities offered by contrast-enhanced ultrasound (CEUS) in the imaging of muscle injuries compared with plain B-mode image ultrasound and MRI imaging of the affected region.
  
  
  METHODS
  This case report is about a high-performance football player who sustained a muscle injury. He underwent an ultrasound examination (S 2000, 9L4 Probe, Siemens, Germany), which was performed simultaneously in the conventional and contrast-enhanced mode at the level of the lesion. An intravenous bolus injection of 4.8 ml of intravascular contrast agent (SonoVue(®), Bracco, Italy) was given via a cubital intravenous line. After that, the distribution of contrast agent was visualised in the early arterial phase. In addition, a plain magnetic resonance imaging scan of both thighs was performed for reference.
  
  
  RESULTS
  On conventional ultrasound, the lesion was not clearly distinguishable from neighbouring tissue, whereas contrast-enhanced ultrasound demonstrated a well delineated, circumscribed area of impaired perfusion with hypoenhancement compared with the surrounding muscles at the clinical level of the lesion in the arterial wash-in phase (0-30 sec, after intravenous administration). The MRI scan revealed an edema signal with perifascial fluid accumulation in the corresponding site.
  
  
  CONCLUSIONS
  The use of intravascular contrast agent enabled the sensitive detection of a minor injury by ultrasound for the first time. An intramuscular edema seen in the MRI scan showed a functional arterial perfusion impairment on ultrasound, which was sensitively detected in the early phase. Further examinations must be performed on muscle injuries of various degrees of severity in order to validate the application of this procedure and to standardise the examination process.
authors.affiliation: Abteilung für Orthopädische Rheumatologie, Orthopädische Universitätsklinik Friedrich-Alexander-Universität Erlangen-Nürnberg.
authors.forename: T
authors.initials: T
authors.lastname: Hotfiel
authors.affiliation: Abteilung für Orthopädische Rheumatologie, Orthopädische Universitätsklinik Friedrich-Alexander-Universität Erlangen-Nürnberg.
authors.forename: H D
authors.initials: HD
authors.lastname: Carl
authors.affiliation: Abteilung für Orthopädische Rheumatologie, Orthopädische Universitätsklinik Friedrich-Alexander-Universität Erlangen-Nürnberg.
authors.forename: B
authors.initials: B
authors.lastname: Swoboda
authors.affiliation: Klinikum Osnabrück, Klinik für Orthopädie, Unfall- und Handchirurgie, Osnabrück.
authors.forename: M
authors.initials: M
authors.lastname: Engelhardt
authors.affiliation: Institut für Radiologie, Universitätsklinikum Erlangen.
authors.forename: M
authors.initials: M
authors.lastname: Heinrich
authors.affiliation: Medizinische Klinik 1, Ultraschallabteilung, Universitätsklinikum Erlangen.
authors.forename: D
authors.initials: D
authors.lastname: Strobel
authors.affiliation: Medizinische Klinik 1, Ultraschallabteilung, Universitätsklinikum Erlangen.
authors.forename: D
authors.initials: D
authors.lastname: Wildner
mesh_terms: D001265:Athletic Injuries / Q000000981:diagnostic imaging*; D003287:Contrast Media; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000293:injuries*; D055420:Perfusion Imaging / Q000379:methods*; D010743:Phospholipids; D012916:Soccer / Q000293:injuries*; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride