title: Quantification of ventricular remodeling in the tight-skin mouse cardiomyopathy with acoustic microscopy.
abstract: To determine the role of ultrasonic tissue characterization for the detection of changes in myocardial architecture associated with cardiomyopathy, acoustic microscopy was performed on the hearts of 4- to 6-month-old tight-skin mice [TSK/+, C57-B10.D2 (58B)/SN strain], a model of cardiomyopathy characterized by diffuse interstitial fibrosis. Ultrasonic backscatter was measured from excised segments of left ventricular free walls of five TSK mice and five sex- and age-matched normal controls with a 50 MHz broad band focused piezoelectric transducer operated in a saline-filled water tank at room temperature. Forty-nine radio frequency (RF) lines were digitized from each specimen at 2 ns/sample. Power spectral analysis of RF data was performed and mean integrated backscatter (IB) computed. The TSK group demonstrated greater IB (-53.6 +/- 0.6 dB, n = 5) than did the control group (-56.6 +/- 0.7 dB, n = 5; p < 0.02). Myocardial collagen content determined by hydroxyproline assay increased by 11% in the TSK group (2.54 +/- 0.08 microgram/mg dry wt, n = 5) over that in controls (2.28 +/- 0.07 microgram/mg dry wt, n = 5; p < 0.05). A significant linear relationship was observed between myocardial hydroxyproline concentration and IB (r = 0.74; p < 0.02). Thus, ultrasonic tissue characterization permits sensitive detection of modest changes in the extent of interstitial fibrosis that accompany tissue remodeling in the early stages of cardiomyopathy.
authors.affiliation: Division of Cardiology, Washington University, St. Louis, MO.
authors.forename: A K
authors.initials: AK
authors.lastname: Wong
authors.forename: T G
authors.initials: TG
authors.lastname: Osborn
authors.forename: J G
authors.initials: JG
authors.lastname: Miller
authors.forename: S A
authors.initials: SA
authors.lastname: Wickline
mesh_terms: D000162:Acoustics; D000818:Animals; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology*; D051379:Mice; D008853:Microscopy / Q000379:methods; D014463:Ultrasonography