Small renal masses: the value of contrast-enhanced colour Doppler imaging

Renal cell carcinoma: real-time contrast-enhanced ultrasound findings

OBJECTIVE

To investigate the findings of renal cell carcinomas (RCCs) on contrast-enhanced ultrasound (CEUS).

METHODS

CEUS features of 84 RCCs confirmed by pathologic examination in 81 patients were retrospectively analyzed. A contrast-specific mode and a sulfur hexafluoride-filled microbubble contrast agent were used for CEUS. The enhancement pattern, extent, and dynamic change in the cortical, corticomedullary, and late phases were evaluated.

RESULTS

On CEUS, the emergence of tumor enhancement was earlier in two nodules (2.4%), simultaneous in 71 (84.5%), and later in 11 (13.1%), in comparison with the adjacent renal cortex. Seventy-four RCC nodules (88.1%) showed hyper-enhancement (n = 2) or iso-enhancement (n = 72) during the cortical phase, and the remaining 10 (11.9%) showed hypo-enhancement. Twenty-three nodules (27.4%) showed homogeneous enhancement and 61 (72.6%) inhomogeneous enhancement. In the corticomedullary phase, the nodules showed hypo-enhancement in 68 (81.0%) and iso-enhancement in 16 (19.0%). In the late phase, all RCCs showed the same enhancement pattern as that shown in the corticomedullary phase. Seventy-two (85.7%) nodules showed a clear perilesional rim-like enhancement in late phase.

CONCLUSIONS

Hyper- or iso-enhancement during the cortical phase, subsequent washout in late phase, inhomogeneous enhancement, and perilesional rim-like enhancement are clues for RCCs, which might be useful for characterization of RCCs.

Incidence and predictive factors of benign renal lesions in Korean patients with preoperative imaging diagnoses of renal cell carcinoma

The present study was performed to determine the incidence and predictive factors of benign renal lesions in Korean patients undergoing nephrectomy for presumed renal cell carcinoma on preoperative imaging. We analyzed the pathologic reports and medical records of 1,598 eligible patients with unilateral, nonmetastatic, and nonfamilial renal masses. Of the 1,598 renal masses, 114 (7.1%) were benign lesions, including angiomyolipoma in 47 (2.9%), oncocytoma in 23 (1.4%), and complicated cysts in 18 (1.1%) patients. On univariate analysis, the proportion of benign lesions was significantly higher in female patients, and in patients with smaller tumors, cystic renal masses, and without gross hematuria as a presenting symptom. When renal lesions were stratified by tumor size, the proportion of benign as opposed to malignant lesions decreased significantly as tumor size increased. On multivariate analysis, female gender, smaller tumor size, and cystic lesions were significantly associated with benign histological features. The findings in this large cohort of Korean patients show a lower incidence (7.1%) of benign renal lesions than those of previous Western reports. Female gender, cystic renal lesions, and smaller tumor size are independent predictors of benign histological features.

Imaging angiogenesis of genitourinary tumors

Angiogenesis is a key process in the growth and metastasis of cancer, and genitourinary tumors are no exception. The evolution of angiogenesis as an important target for novel anticancer therapeutics has brought with it new challenges for in vivo imaging. Most imaging techniques quantify physiological parameters, such as blood volume and capillary endothelial permeability. Although CT, PET and ultrasonography have shown promise, MRI is the most common method used to evaluate angiogenesis in clinical trials of genitourinary tumors. Pilot studies of MRI, CT and ultrasonography in patients with renal cancer have produced promising results; reductions in vascular permeability and blood flow have been correlated with progression-free survival. The vascular characteristics of prostate cancer have been evaluated by MRI, and this has been suggested as a means of assessing tumor response to hormone deprivation therapy. Current evidence highlights the potential of angiogenesis imaging in the diagnosis, staging and possibly response monitoring of bladder cancer. In the future, assessment of the angiogenic process at the structural, functional and molecular levels, before, during and after antiangiogenic therapy will undoubtedly be integrated into wider clinical practice.

Imaging findings of genitourinary tumors in the elderly

Aging-correlated pathologies are atherosclerosis, arterial hypertension, diabetes mellitus, bacterial infections, and malnutrition. The progressive impairment of renal function is the cause of the drug-induced renal pathologies: direct damage induced by nephrotoxic drugs or indirect damage induced by decreased renal excretion of serum molecules. In the elderly, an increase in different pathologies occurs in the genitourinary tract. Among these pathologies, an increase in neoplastic disorders is present; at the same time, several non-neoplastic pathologies are more frequent in old patients. This article considers first the neoplastic genitourinary pathologies and second the non-neoplastic genitourinary pathologies.

Contrast-enhanced ultrasound for diagnosis of prostate cancer and kidney lesions

PURPOSE OF REVIEW

Conventional ultrasonography of both, kidney and prostate, is limited due to the poor contrast of B-mode imaging for parenchymal disease and limited sensitivity of colour Doppler for the detection of capillaries and deep pedicular vessels. Contrast-enhanced ultrasound (CEUS) overcomes these limitations.

RECENT FINDINGS

CEUS investigates the blood flow of the prostate, allows for prostate cancer visualization and for targeted biopsies. Comparisons between systematic and CEUS-targeted biopsies have shown that the targeted approach detects more cancers with a lower number of biopsy cores and with higher Gleason scores compared with the systematic approach. Also the kidney offers promising applications as CEUS improves the detection of abnormal microvascular and macrovascular disorders.

SUMMARY

In recent literature CEUS has shown its value for diagnosis of both, prostate cancer and kidney lesions. This paper describes recent improvements and future perspectives of CEUS.