Fractal mathematics: method to quantitate the patterns seen in nature. The fractal dimension of tumor vasculature describes the relative volume of repeatable branching.
Power weighted pixel density: weighs the vascularity relative to the amplitude of the color signal.
Tumor neovascularity: microscopic network of abnormal vessels induced from host vasculature to supply a tumor.
Vascularity index: quantification of pixels containing color divided by total volume of tissue.
Transvaginal sonography (TVS) affords detailed assessment of the morphology of pelvic masses; however, the morphology of adnexal masses depicted by TVS is nonspecific at times. Color Doppler sonography (CDS) with spectral analysis has added to our understanding and characterization of these lesions based on its depiction of vascularity of the mass. Using two-dimensional (2D) and/or three-dimensional (3D) CDS, it is possible to demonstrate the origin of the mass and to detect areas of abnormal neovascularity.
Color Doppler sonography depicts the pelvic vessels supplying the ovary and uterus. Spectral analysis correlates a variety of anatomic and physiologic parameters such as:
Vessel characteristics such as the presence of a muscular media
Certain physiologic processes, such as vasodilation or vasoconstriction
Vascular configuration of certain parenchymal beds
Inherent interstitial pressure within the tumor
In general, CDS serves as an adjunct to the morphologic assessment of pelvic masses demonstrated on sonography (Figure 32-1). A double-blinded study from our institution showed that CDS added clinically important information in approximately 40% of the patients undergoing TVS for a pelvic mass.1 A combination of TVS and CDS provides assessment of adnexal masses on a physiologic, rather than on a merely morphologic, basis.2,3
Diagram showing transvaginal color Doppler sonography. The triplex image consists of a gray-scale depiction of the anatomy in the field of view, a duplex Doppler with a selectable sample volume over a vessel, and a Doppler waveform whose height is dependent in velocities versus time from a specific intraovarian vessel.
This chapter discusses and illustrates the technique for performing CDS on patients with pelvic masses. It also outlines the role of CDS in the diagnosis of the adnexal masses, including its differentiation of benign from malignant masses. Limitations in assessment of benign versus malignant histopathology and pitfalls of the examination are presented.4,5 Special indications including the use of this modality in screening programs and in postmenopausal women who have adnexal masses also are addressed.6
NORMAL OVARIAN ANATOMY AND FLOW
The ovary is an ovoid structure that is nestled between the roughly middle positioned uterus and the internal iliac vessels, which are located along the lateral pelvic sidewall. The volume of the ovary changes with the patient's hormonal status and has an average volume of 4.2 cm3 in the adolescent period, ...