Overview: the current role of the vascular diagnostic laboratory.

摘要: T HE TESTING METHODS used in the noninvasive vascular diagnostic laboratory have evolved over last 40 years to bridge gap between subjective clinical assessment of disorders and invasive contrast studies arteries veins. Many early tests utilized continuous wave Doppler ultrasound detect blood flow. These were referred as indirect methods because they relied on detection major changes pressure or flow produced by arterial venous disease. Therefore, only hemodynamically significant lesions could be identified reliably. The included periorbital examination for extracranial carotid artery disease, evaluation deep vein thrombosis, segmental measurement extremities. Some these tests, such ankle systolic pressure, still are useful setting, but most given way direct approach duplex scanning. 1 principal advantage scanning is that it obtains both anatomic physiologic information directly from sites Since emerged 1980s preferred test advances technology extended its applications vessels abdomen This combination B-mode imaging spectral analysis pulsed signals provided first opportunity accurately characterize disease without resorting procedures. based concept produce localized disturbances patterns can characterized signals. Accordingly, image place a sample volume within vessel interest, local pattern assessed waveform analysis. Although may valuable identifying variants, wall thickening calcification, thrombi system, has not been possible determine degree narrowing alone. classification severity mainly interpretation waveforms. Color-flow an alternative displaying information. Within certain technical limitations, color-flow permits visualization moving plane image; helpful vessels, particularly when small, deeply located, anatomically complex. However, difficult assess alone, waveforms necessary accurate classification. While initially was interest