ABSTRACT
INTRODUCTION: Although transrectal ultrasound is routinely performed for imaging prostate lesions, colour Doppler imaging visualizing vascularity is not commonly used for diagnosis. The goal of this study was to measure vascular and echogenic differences between malignant and benign lesions of the prostate by quantitative colour Doppler and greyscale transrectal ultrasound. METHODS: Greyscale and colour Doppler ultrasound images of the prostate were acquired in 16 subjects with biopsy-proven malignant or benign lesions. Echogenicity and microvascular flow velocity of each lesion were measured by quantitative image analysis. Flow velocity was measured over several cardiac cycles and the velocity-time waveform was used to determine microvascular pulsatility index and microvascular resistivity index. The Wilcoxon rank sum test was used to compare the malignant and benign groups. RESULTS: Median microvascular flow velocity of the malignant lesions was 1.25 cm/s compared to 0.36 cm/s for the benign lesions. Median pulsatility and resistive indices of the malignant lesions were 1.55 and 0.68, respectively versus 6.38 and 1.0 for the benign lesions. Malignant lesions were more hypoechoic relative to the surrounding tissue, with median echogenicity of 0.24 compared to 0.76 for the benign lesions. The differences between the malignant and benign groups for each measurement were significant (p < 0.01). CONCLUSION: Marked differences were observed in flow velocity, microvascular pulsatility, microvascular resistance, and echogenicity of prostate cancer measured with quantitative colour Doppler and greyscale ultrasound imaging. Vascular differences measured together with echogenicity have the combined potential to characterize malignant and benign prostate lesions.
ABSTRACT
Ultrasonographically (US) guided percutaneous biopsy of a neck lesion is a cost-effective, safe, and diagnostically effective procedure without radiation exposure. The benefit of real-time visualization of the needle location allows for instantaneous maneuvering of the needle trajectory for safe and accurate tissue sampling with short procedural time. Effective US-guided biopsy requires technical experience, strong clinical acumen, and skillful biopsy technique. A neuroradiologist's knowledge of head and neck anatomy and pathology allows correlation with cross-sectional imaging and enhances the understanding of US imaging evaluation. Familiarity with a spectrum of neck surgeries and reconstructions and expertise in imaging evaluation of the treated neck are invaluable in accurate identification of the target for biopsy in patients with treatment-related altered anatomy using US guidance. After thyroid nodules, the common adult neck masses are lymphadenopathy, head and neck cancer, salivary neoplasms, nerve sheath tumors, and inflammatory and infectious pseudomasses. Diagnostic expertise in the imaging characteristics of these individual pathologic conditions and their differential diagnoses also play an important role in choosing the biopsy technique and in procuring an adequate sample for diagnosis, including material for ancillary laboratory testing. Using an anatomic zone approach, this article illustrates the practical considerations in patient selection, the methodical analysis of preprocedure cross-sectional imaging and its correlation with real-time US evaluation, general principles for optimizing US instrumentation, and biopsy technique. In skillful hands, the versatility and portability of US make it the valuable modality for histologic sampling of superficial head and neck lesions. Online supplemental material is available for this article.
