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

Abstract

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.

Seeing and Sensing the Hepatorenal Syndrome (HRS): The Growing Role of Ultrasound-Based Techniques as Non-Invasive Tools for the Diagnosis of HRS

“…This technique represents a quantitative assessment of ultrasound contrast agent kinetics (UCA) in a specific region of interest (ROI), generated using time intensity curve (TIC) analysis. Two main parameters were measured: amplitude (linked to blood volume) and time (related to blood flow) [60]. D-CEUS, with the blood flow analysis of the hepatic parenchyma, was used as a non-invasive tool to predict the stage of liver fibrosis and the clinical portal hypertension in patients with compensated advanced liver disease, as seen in some of the previous studies [61][62][63].…”

Current Developments and Role of Intestinal Ultrasound including the Advent of AI

“…There are two ways to generate quantitative estimates: the first one is called disruptionreplenishment analysis, which relies on the continuous injection of the contrast for 5-20 min and the analysis of microbubble replacement kinetics after destruction with ultrasound waves. The second, more frequently utilized method is the wash-in/wash-out analysis, in which thanks to the data acquired during continuous registration after the bolus injection of the contrast agent, a time-intensity curve (TIC) is generated to estimate different measures such as the time to peak (TTP), peak intensity (PI), area under the curve (AUC), washin slope (P w ), and mean transit time (MTT), all these different data being presented in log-normal to reduce the range of values and make them more manageable [46].…”

Transabdominal ultrasound for the diagnostic workup of parenchymal pancreatic diseases

“…Die Time-Intensity-Curve stellt die Möglichkeit einer quantitativen Analyse der CEUS dar. Die Technik wird am Pankreas bisher fast ausschließlich zur Charakterisierung fokaler Läsionen eingesetzt 26 . In Zukunft könnte dieses Tool jedoch auch zur Einschätzung des Schweregrades und damit zur Risikostratifizierung bei akuter Pankreatitis beitragen.…”

“…The time intensity curve allows quantitative analysis of CEUS. With respect to the pancreas, the technique is currently used almost exclusively to characterize focal lesions [26]. However, in the future, this tool could also help to evaluate severity and thus for risk stratification in acute pancreatitis.…”