Ultrasonic Imaging · 1993 · 171 citations · 0 references
Veterinary MedicineBioengineeringBiomedical EngineeringBiomedical ImagingDiagnostic ImagingUltrasonographyBreast UltrasonographyDiagnostic UltrasonographyElastographyUltrasonicsUltrasound ImagingUltrasound PhysicsBreast ElastographyBreast Ultrasound ElastographyElasticityElasticity Imaging AssessmentLinear Array TransducersMuscle ElastographySingle-element TransducersUltrasonic Elastography
Tissue elasticity correlates with pathology, yet small or deep lesions are often undetectable by palpation or ultrasound, prompting the development of elastography—a method that images tissue elasticity using ultrasound. The study introduces a new linear‑array transducer elastography system designed for in‑vivo scanning. The system estimates local strain from one‑dimensional displacement, combines it with stress estimates to compute elastic modulus, and displays the result as a gray‑.
Changes in tissue elasticity are generally correlated with its pathological state. In many cases, despite the difference in elasticity, the small size of a lesion or its location deep in the body preclude its detection by palpation. In general, such a lesion may or may not posses echogenic properties that would make it ultrasonically detectable. Elastography is an ultrasonic method for imaging the elasticity of compliant tissues. The method estimates the local longitudinal strain of tissue elements by ultrasonically assessing the one dimensional local displacements. This information can be combined with first order theoretical estimates of the local stress to yield a quantitative measure of the local elastic properties of tissue. The elasticity information is displayed in the form of a gray scale image called an elastogram. An experimental system for elastography in phantoms based on a single element transducer has been described previously [1]. Here we introduce a new elastography system based on a linear array transducer that is suitable for in vivo scanning. We describe tissue mimicking phantom experiments and preliminary in vivo breast and muscle elastograms confirming the feasibility of performing elastography in vivo. An elastogram of a breast containing an 8 mm palpable cancer nodule clearly shows the lesion. Elastograms and their corresponding sonograms show some similarities and differences in the depiction of tissue structures.