title: Ultrasound Strain Elastography in Assessment of Muscle Stiffness in Acute Levodopa Challenge Test: A Feasibility Study.
abstract: To evaluate the feasibility of ultrasound strain elastography in assessing the response of muscle stiffness to the acute levodopa test, we prospectively performed strain elastography on the biceps brachii muscle (BBM) of 18 patients to diagnose Parkinson's disease. BBM and subcutaneous tissue strains (deformations) were produced by external compression with an ultrasound transducer and estimated using 2-D speckle tracking. We used the strain ratio (SR = BBM strain/reference strain) to assess BBM stiffness. The rate of increase in SR [rate = (SR after levodopa-SR before levodopa)/SR before levodopa] was used to assess the muscle stiffness response to levodopa. SR significantly increased after levodopa administration in 11 patients with Parkinson's disease (p = 0.02), whereas it did not in 7 patients with parkinsonian syndrome (from non-Parkinson's causes) (p = 0.14). The area under the receiver operating characteristic curve for the rate of increase in SR in determining Parkinson's disease was 0.96. The rate of increase in SR seems to be feasible in evaluating the effect of levodopa on muscle stiffness in the diagnosis of Parkinson's disease.
authors.affiliation: Department of Radiology, Weill Cornell Medical College, New York, New York, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Du
authors.affiliation: Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China. Electronic address: ttyyus@sina.com.
authors.forename: Wen
authors.initials: W
authors.lastname: He
authors.affiliation: Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Ling-Gang
authors.initials: LG
authors.lastname: Cheng
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents; D055119:Elastic Modulus / Q000187:drug effects; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007980:Levodopa; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000503:physiopathology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa
keywords: Acute levodopa challenge test; Muscle rigidity; Parkinson's disease; Speckle tracking; Ultrasound strain elastography