title: Comparison of transient arterial occlusion and muscle exercise provocation for assessment of perfusion reserve in skeletal muscle with real-time contrast-enhanced ultrasound.
abstract: OBJECTIVE
  Contrast-enhanced ultrasound (CEUS) is able to quantify muscle perfusion and changes in perfusion due to muscle exercise in real-time. However, reliable measurement of standardized muscle exercise is difficult to perform in clinical examinations. We compared perfusion reserve assessed by CEUS after transient arterial occlusion and exercise to find the most suitable measurement for clinical application.
  
  
  METHODS
  Contrast pulse sequencing (7 MHz) during continuous IV infusion of SonoVue(®) (4.8 mL/300 s) was used in 8 healthy volunteers to monitor muscle perfusion of the gastrocnemius muscle during transient (1 min) arterial occlusion produced by a thigh cuff of a venous occlusion plethysmograph. Isometric muscle exercise (50% of individual maximum strength for 20s) was subsequently performed during the same examination, and several CEUS parameters obtained from ultrasound-signal-intensity-time curves and its calculation errors were compared.
  
  
  RESULTS
  The mean maximum local blood volume after occlusion was 13.9 [∼mL] (range, 4.5-28.8 [∼mL]), and similar values were measured after sub-maximum exercise 13.8 [∼mL], (range, 4.6-22.2 [∼mL]. The areas under the curve during reperfusion vs. recovery were also similar (515.2±257.5 compared to 482.2±187.5 [∼mLs]) with a strong correlation (r=0.65), as were the times to maximum (15.3s vs. 15.9s), with a significantly smaller variation for the occlusion method (±2.1s vs. ±9.0s, p=0.03). The mean errors for all calculated CEUS parameters were lower for the occlusion method than for the exercise test.
  
  
  CONCLUSIONS
  CEUS muscle perfusion measurements can be easily performed after transient arterial occlusion. It delivers data which are comparable to CEUS measurements after muscle exercise but with a higher robustness. This method can be easily applied in clinical examination of patients with e.g. PAOD or diabetic microvessel diseases to assess perfusion reserve.
authors.affiliation: German Cancer Research Center, Research Program Imaging and Radiooncology, Department of Radiology, INF 280, D-69120 Heidelberg, Germany. martin.krix@kabelbw.de
authors.forename: Martin
authors.initials: M
authors.lastname: Krix
authors.forename: Holger
authors.initials: H
authors.lastname: Krakowski-Roosen
authors.forename: Erick
authors.initials: E
authors.lastname: Amarteifio
authors.forename: Erick
authors.initials: E
authors.lastname: Armarteifio
authors.forename: Susanne
authors.initials: S
authors.lastname: Fürstenberger
authors.forename: Stefan
authors.initials: S
authors.lastname: Delorme
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Weber
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000502:physiology*; D055420:Perfusion Imaging / Q000379:methods*; D010743:Phospholipids; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride