Quantitative Perfusion Analysis of Contrast-enhanced Ultrasound Might Help Differentiate Benign and Malignant Solid Cystic Lesions of the Kidney: A Case Report and Literature Review

BACKGROUND

Mixed epithelial and stromal tumor of the kidney (MESTK) is a rare benign lesion that appears as a solid cystic renal lesion or complex renal cystic lesion on medical imaging. There are no definite imaging criteria for METSK diagnosis.

CASE PRESENTATION

We present a case of a solid cystic renal mass that was evaluated by contrast-enhanced ultrasound (CEUS) during an imaging workup. The patient underwent nephrectomy and histopathological confirmation of MESTK. The lesions showed hypoenhancement during the process. Quantitative perfusion analysis showed the septation of the solid cystic lesion to have lower peak enhancement with a longer rise time compared to the normal renal cortex.

DISCUSSION

CEUS can visualize the microcirculation of the organ and reconstruction of the vessels. By providing a more detailed visualization of the microvessel, CEUS is a useful tool for further characterizing renal lesions that show indeterminate enhancement on CT. This study determined the time to peak to be shorter for the cancerous lesion than the normal renal cortex, while peak intensity did not differ between the cancerous lesion and the normal renal cortex.

CONCLUSION

Quantitative perfusion analysis of CEUS may be useful for differentiating benign and malignant solid cystic renal masses. Further investigation is needed to determine whether peak intensity is a useful parameter in differentiating benign and malignant solid cystic lesions of the kidney.

Dynamic contrast enhanced ultrasound in gastrointestinal diseases: A current trend or an indispensable tool?

Contrast enhanced ultrasound (CEUS) has been widely implemented in clinical practice because of the enormous quantity of information it provides, along with its low cost, reproducibility, minimal invasiveness, and safety of the second-generation ultrasound contrast agents. To overcome the limitation of CEUS given by the subjective evaluation of the contrast enhancement behaviour, quantitative analysis of contrast kinetics with generation of time-intensity curves has been introduced in recent years. The quantification of perfusion parameters [named as dynamic-CEUS (D-CEUS)] has several applications in gastrointestinal neoplastic and inflammatory disorders. However, the limited availability of large studies and the heterogeneity of the technologies employed have precluded the standardisation of D-CEUS, which potentially represents a valuable tool for clinical practice in management of gastrointestinal diseases. In this article, we reviewed the evidence exploring the application of D-CEUS in gastrointestinal diseases, with a special focus on liver, pancreas, and inflammatory bowel diseases.

Characterization of Pancreatic Tumors with Quantitative Perfusion Analysis in Contrast-Enhanced Harmonic Endoscopic Ultrasonography

OBJECTIVES

This study evaluated whether quantitative perfusion analysis with contrast-enhanced harmonic (CH) endoscopic ultrasonography (EUS) characterizes pancreatic tumors, and compared the hemodynamic parameters used to diagnose pancreatic carcinoma.

METHODS

CH-EUS data from pancreatic tumors of 76 patients were retrospectively analyzed. Time-intensity curves (TIC) were generated to depict changes in signal intensity over time, and 6 parameters were assessed: baseline intensity, peak intensity, time to peak, intensity gain, intensity at 60 s (I60), and reduction rate. These parameters were compared between pancreatic carcinomas (n = 41), inflammatory pseudotumors (n = 14), pancreatic neuroendocrine tumors (n = 14), and other tumors (n = 7). All 6 TIC parameters and subjective analysis for diagnosing pancreatic carcinoma were compared.

RESULTS

Values of peak intensity and I60 were significantly lower and time to peak was significantly longer in the groups with pancreatic carcinomas than in the other 3 tumor groups (p < 0.05). Reduction rate was significantly higher in pancreatic carcinomas than in pancreatic neuroendocrine tumors (p < 0.05). Areas under the receiver-operating characteristic curves for the diagnosis of pancreatic carcinoma using subjective analysis, baseline intensity, peak intensity, intensity gain, I60, time to peak, and reduction rate, were 0.817, 0.664, 0.810, 0.751, 0.845, 0.777, and 0.725, respectively. I60 was the most accurate parameter for differentiating pancreatic carcinomas from the other groups, giving values of sensitivity/specificity of 92.7/68.6% when optimal cutoffs were chosen.

CONCLUSIONS

In pancreatic carcinomas, TIC patterns were markedly different from the other tumor types, with I60 being the most accurate diagnostic parameter. Quantitative perfusion analysis is useful for differentiating pancreatic carcinomas from other pancreatic tumors.