Guidelines for the use of contrast-enhanced ultrasound in hepatocellular carcinoma

Abstract Surveillance of patients at risk of developing hepatocellular carcinoma (HCC) relies on ultrasound (US) examinations performed at 6-month intervals. Early detection of HCC on a cirrhotic background is a challenging issue, since the US features of the different entities in the multi-step process of hepatocarcinogenesis – such as low-grade and high-grade dysplastic nodule – do overlap. Contrast-enhanced US allows reliable detection of arterial neo-angiogenesis associated with the malignant change. Several reports have shown that the ability of contrast-enhanced US to diagnose HCC currently approaches that of optimised multidetector computed tomography (CT) or dynamic magnetic resonance (MR) imaging protocols. The use of contrast-enhanced US to characterise nodular lesions in cirrhosis has recently been recommended by the clinical practice guidelines issued by the European Federation of Societies for Ultrasound in Medicine and Biology and the American Association for the Study of Liver Diseases. Contrast-enhanced US has also been successfully used to assess response of HCC to image-guided percutaneous ablation procedures. In this article, we discuss the advantages and limitations of contrast-enhanced US with respect to the other imaging modalities in the setting of HCC

A first look into radiomics application in testicular imaging: A systematic review

The aim of this systematic review was to evaluate the state of the art of radiomics in testicular imaging by assessing the quality of radiomic workflow using the Radiomics Quality Score (RQS) and the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). A systematic literature search was performed to find potentially relevant articles on the applications of radiomics in testicular imaging, and 6 final articles were extracted. The mean RQS was 11,33 ± 3,88 resulting in a percentage of 31,48% ± 10,78%. Regarding QUADAS-2 criteria, no relevant biases were found in the included papers in the patient selection, index test, reference standard criteria and flow-and-timing domain. In conclusion, despite the publication of promising studies, radiomic research on testicular imaging is in its very beginning and still hindered by methodological limitations, and the potential applications of radiomics for this field are still largely unexplored

Impact of European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines on the use of contrast agents in liver ultrasound

Conclusions: Despite the improvement in detection and characterization of focal liver lesions that can be achieved by using contrast-enhanced US, several issues remain to be resolved. First, contrast US will hardly replace CT or MR imaging for preoperative assessment of patients with liver tumors, as these techniques still offer a more comprehensive assessment of the liver parenchyma, which is mandatory to properly plan any kind of surgical or interventional procedure. Second, the daily schedule of each US laboratory doing liver examinations will have to be reformulated, and many such laboratories will have to update their equipment and provide proper training for their doctors. Last but not least, the cost of the introduction of contrast-enhanced US into daily practice will have to be taken into account. It can be argued that cost savings associated with patients who will no longer need CT or MR imaging of the liver after contrast-enhanced US could largely counterbalance the cost of the examination. However, an optimal use of contrast-enhanced US will require precise diagnostic flow charts for each clinical situation. Nevertheless, contrast-enhanced US has the potential to become the primary liver-imaging modality for early detection and characterization of focal lesions. Early diagnosis of primary and secondary liver malignancies greatly enhances the possibility of curative surgical resection or successful percutaneous ablation, resulting in better patient care and eventually in improved patient survival. © 2006 Springer-Verlag Italia

Contrast-Enhanced Doppler Ultrasound of Renal Artery Stenosis: Prologue to a Promising Future

Over the past few years, there has been extensive research for a reliable, noninvasive, and nonionizing imaging method to screen for renal artery stenosis (RAS). Doppler ultrasound (US) is one of many modalities that have been evaluated for the detection of RAS. The lack of standardization in examination protocols and diagnostic criteria, as well as the wide differences in reported accuracy among different laboratories, however, have prevented universal acceptance of this technique as a reliable screening test for RAS. Recently, the introduction of US contrast agents has substantially expanded the potentials of color Doppler US. The use of microbubble echo enhancers in combination with harmonic Doppler imaging has been shown to improve diagnostic confidence by improving the operator's ability to visualize the renal arteries, and to significantly reduce the number of equivocal examinations. In addition, contrast-enhanced harmonic Doppler US can currently provide objective functional assessment of RAS through analysis of time-intensity renal enhancement curve. State-of-the-art contrast-enhanced Doppler US seems to have the potential to become a useful screening test for patients at risk from renovascular hypertension and a tool for follow-up of patients who undergo revascularization procedure

Guidelines for imaging focal lesions in liver cirrhosis

Imaging cirrhotic patients for early detection of hepatocellular carcinoma remains a challenging issue despite many technological advances. In fact, nonmalignant hepatocellular lesions, such as regenerative or dysplastic nodules, may mimic a small tumor. Imaging protocols are aimed at showing the different vascular supply to the lesion. It is accepted that dynamic contrast-enhanced imaging techniques, including contrast ultrasound, multidetector computed tomography and magnetic resonance imaging, can establish the diagnosis of hepatocellular carcinoma in nodular lesions larger than 1 cm showing arterial hypervascularization with venous washout. Magnetic resonance imaging in combination with liver-specific contrast agents, including hepatocyte-targeted and reticuloendothelial system-targeted agents, may be useful to clarify questionable cases, due to its ability to show changes in hepatobiliary function or Kuppfer cell content associated with malignancy. However, even optimized imaging techniques remain relatively insensitive for the detection of tiny satellite nodules associated with the main tumor