Expanding the Role of Ultrasound for the Characterization of Renal Masses

Abstract

The incidental detection of renal masses has been steadily rising. As a significant proportion of renal masses that are surgically treated are benign or indolent in nature, there is a clear need for better presurgical characterization of renal masses to minimize unnecessary harm. Ultrasound is a widely available and relatively inexpensive real-time imaging technique, and novel ultrasound-based applications can potentially aid in the non-invasive characterization of renal masses. Evidence acquisition: We performed a narrative review on novel ultrasound-based techniques that can aid in the non-invasive characterization of renal masses. Evidence synthesis: Contrast-enhanced ultrasound (CEUS) adds significant diagnostic value, particularly for cystic renal masses, by improving the characterization of fine septations and small nodules, with a sensitivity and specificity comparable to magnetic resonance imaging (MRI). Additionally, the performance of CEUS for the classification of benign versus malignant renal masses is comparable to that of computed tomography (CT) and MRI, although the imaging features of different tumor subtypes overlap significantly. Ultrasound molecular imaging with targeted contrast agents is being investigated in preclinical research as an addition to CEUS. Elastography for the assessment of tissue stiffness and micro-Doppler imaging for the improved detection of intratumoral blood flow without the need for contrast are both being investigated for the characterization of renal masses, though few studies have been conducted and validation is lacking. Conclusions: Several novel ultrasound-based techniques have been investigated for the non-invasive characterization of renal masses. CEUS has several advantages over traditional grayscale ultrasound, including the improved characterization of cystic renal masses and the potential to differentiate benign from malignant renal masses to some extent. Ultrasound molecular imaging offers promise for serial disease monitoring and the longitudinal assessment of treatment response, though this remains in the preclinical stages of development. While elastography and emerging micro-Doppler techniques have shown some encouraging applications, they are currently not ready for widespread clinical use.

Current Imaging Techniques in Renal Cell Carcinoma

“…Current Imaging Techniques in Renal Cell Carcinoma DOI: http://dx.doi.org/10.5772/intechopen.107834 benign lesion (Figure 2). Difference of perfusion within the lesion and surrounding renal cortex helps to characterize solid lesions also [1].…”

“…analysis of time intensity curves help in distinction of various subtypes of RCC and from typical AML from RCC. However, there is considerable overlap in imaging features of these masses [1].…”

“…Renal cell carcinoma is the most common renal malignancy. The steady increase in incidental diagnosis of small renal cancers in last several decades can partly be dedicated to frequent abdominal imaging [1]. The risk benefit ratio has to be considered while resecting a renal mass for the presumption of cancer which can turn out to be of benign or indolent nature.…”

“…The risk benefit ratio has to be considered while resecting a renal mass for the presumption of cancer which can turn out to be of benign or indolent nature. Per cutaneous renal biopsy can be the gold standard for such pre surgical diagnosis; however it yields non diagnostic rate of 10-15% and the intra tumoral heterogeneity hampers its widespread use [1]. Hence, accurate pre surgical characterization of renal cancers is very needful to avoid over treatment and to facilitate the proper line of treatment to the surgeon.…”

“…The basic disadvantage of USG is its operator dependency. Though USG is sufficient to differentiate simple or minimally complex cystic masses as benign lesions, it is not reliable to differentiate more complex cystic and solid lesions [1]. Newer advances in USG like contrast enhanced Ultrasound, ultrasound molecular imaging, elastography and micro doppler techniques are nowadays being investigated for better accuracy of ultrasound and to expand its role in tumor characterization.…”