Correlation of Doppler US tumor signals with neovascular morphologic features.

Abstract

Abnormal Doppler ultrasound signals were detected in 44 of 47 patients with primary malignant tumors of the liver, kidney, adrenal gland, or pancreas (94%). Two different signal types were noted: a high-velocity signal (n = 38) with Doppler shifts exceeding 3 kHz (at an insonating frequency of 3 MHz) and a very low-impedance signal (n = 9) demonstrating little systolic-diastolic variation. In three patients, both types were present. In 19 patients, histologic (n = 12) and/or angiographic (n = 16) correlation was available. Among 13 patients with angiographic studies and signals over 3 kHz, arteriovenous shunting was demonstrated in six. The ratio of the systolic to diastolic Doppler shift is a function of vascular impedance. This systolic/diastolic index was less than 3 in eight patients with histologic correlation. All eight had prominent vascular spaces, and the flow in such thin-walled, endothelium-lined spaces would account for the low-impedance signals. Of nine patients with systolic/diastolic indexes of 3 or less and angiographic correlation, three had marked and four had moderate tumor staining.

Dynamic assessment of antiangiogenic therapy by monitoring both tumoral vascularization and tissue degeneration

“…37 New interest has developed in contrast-enhanced ultrasound techniques as the unenhanced Doppler ultrasound applied within tumors only depict large vessels (4100 mm) confined to superficial parts of the body. 9,10 Even if previous studies have reported that unenhanced power-mode Doppler ultrasound system is capable of detecting the velocity of blood flow through tumor vessels as small as 10-20 mm in diameter, this imaging system used high frequencies Dynamic assessment of angiogenesis and necrosis in tumor mass C Magnon et al (50 MHz) and a focused transducer to improve the ultrasound signal resolution and focal characteristics. Nevertheless, this technique is not applicable in clinical settings because high frequency (20-100 MHz) decreases exploration depth, impeding the assessment of deep tumors.…”

“…7,8 The detection threshold of CDUS is approximately 100 mm in vessel diameter. 9,10 However, a new clinical approach consists in using microbubble contrast agents, such as Levovist, to increase acoustic signal sensitivity reflecting microvascular perfusion. [11][12][13] In order to predict antiangiogenic effects over a treatment period, contrast-enhanced HFCDUS was used in this study.…”

Soft-tissue hemangiomas in infants and children: diagnosis using Doppler sonography.

“…Very high Doppler shifts have been detected at the peripheiy of numerous malignant tumors, especially in the abdomen [10,11]. It is not likely thata malignant tumorwouldmimicthe high density ofvessels throughout its mass that is seen in hemangiomas.…”

Resistance to blood flow in ovarian tumors: correlation between resistance index and histological pattern of vascularization

“…Often the larger components of the microcirculation lack smooth muscle. They are described as large capillaries, sinusoids or, alternatively, as primitive vascular channels lacking smooth muscle and often consisting of an endothelial layer and connective tissue alone 14 . They show variation in caliber.…”

“…They show variation in caliber. Some vessels terminate in wide sinusoids (instead of minute capillaries) or form arteriovenous shunts 14,15 .…”