Benefits of contrast-enhanced ultrasonography for interventional procedures

Postoperative Spinal Cord Ischemia Monitoring: A Review of Techniques Available After Endovascular Aortic Repair

BACKGROUND

Spinal cord ischemia is one of the complications that can occur after open and endovascular thoracoabdominal aortic repair. This occurs despite various perioperative approaches, including distal aortic perfusion, hybrid procedures with extra anatomical bypasses, motor-evoked potential, and cerebrospinal fluid drainage. The inability to recognize spinal ischemia in a timely manner remains a devastating complication after thoracoabdominal aortic repair.

OBJECTIVES

This review aims to look at novel technologies that are designed for continuous monitoring to detect early changes that signal the development of spinal cord ischemia and to discuss their benefits and limitations.

METHODS

We conducted a systematic review of the technologies available for continuous monitoring in the intensive care unit (ICU) for early detection of spinal cord ischemia. Studies were eligible for inclusion if they used different technologies for monitoring spinal ischemia during the postoperative period. All articles that were not available in English were excluded. To ensure that all relevant articles were included, no other significant restrictions were imposed.

RESULTS

We identified 59 studies from outset to December 2022 to be included in our study. New techniques have been studied as potentially useful monitoring tools that could provide simple and effective monitoring of the spinal cord. These include Near-infrared spectroscopy, Contrast-enhanced ultrasound, Magnetic Resonance Imaging, fiber optic monitoring of the spinal cord, and CSF biomarkers.

CONCLUSION

Despite the development of new techniques to monitor for postoperative spinal cord ischemia, their use remains limited. We recommend more future research to ensure rapid intervention for our patients.

The Clinical Value of Multimodal Ultrasound for the Differential Diagnosis of Hepatocellular Carcinoma from Other Liver Tumors in Relation to Histopathology

Recent advances in the field of ultrasonography offer promising tools for the evaluation of liver tumors. We aim to assess the value of multimodal ultrasound in differentiating hepatocellular carcinomas (HCCs) from other liver lesions. We prospectively included 66 patients with 72 liver tumors. The histological analysis was the reference standard for the diagnosis of malignant liver lesions, and partially for benign tumors. All liver lesions were assessed by multiparametric ultrasound: standard ultrasound, contrast-enhanced ultrasound (CEUS), the point shear wave elastography (pSWE) using shear wave measurement (SWM) method and real-time tissue elastography (RTE). To diagnose HCCs, CEUS achieved a sensitivity, specificity, accuracy and positive predictive value (PPV) of 69.05%, 92.86%, 78.57% and 93.55%, respectively. The mean shear-wave velocity (Vs) value in HCCs was 1.59 ± 0.29 m/s, which was lower than non-HCC malignancies (p < 0.05). Using a cut-off value of 1.58 m/s, SWM achieved a sensitivity of 54.76%, and 82.35% specificity, for differentiating HCCs from other malignant lesions. The combination of SWM and CEUS showed higher sensitivity (79.55%) compared with each technique alone, while maintaining a high specificity (89.29%). In RTE, most HCCs (61.53%) had a mosaic pattern with dominant blue areas corresponding to type "c" elasticity. Elasticity type "c" was 70.59% predictive for HCCs. In conclusion, combining B-mode ultrasound, CEUS, pSWE and RTE can provide complementary diagnostic information and potentially decrease the requirements for other imaging modalities.

Radiation Dose Reduction Opportunities in Vascular Imaging

Computed tomography angiography (CTA) has been the gold standard imaging modality for vascular imaging due to a variety of factors, including the widespread availability of computed tomography (CT) scanners, the ease and speed of image acquisition, and the high sensitivity of CTA for vascular pathology. However, the radiation dose experienced by the patient during imaging has long been a concern of this image acquisition method. Advancements in CT image acquisition techniques in combination with advancements in non-ionizing radiation imaging techniques including magnetic resonance angiography (MRA) and contrast-enhanced ultrasound (CEUS) present growing opportunities to reduce total radiation dose to patients. This review provides an overview of advancements in imaging technology and acquisition techniques that are helping to minimize radiation dose associated with vascular imaging.

Diagnostic Performance of Contrast-Enhanced Ultrasound in the Evaluation of Small Renal Masses: A Systematic Review and Meta-Analysis

Ultrasound (US) is a highly sensitive imaging tool in the detection of renal masses. However, the detection rate of small renal masses (SRMs) (<4 cm) is still limited. In this scenario, contrast-enhanced ultrasound (CEUS) is a relatively novel, but increasingly utilized, diagnostic modality which aims to increase the overall diagnostic ability in the identification of SRMs. In consequence, we performed a systematic review (SR) and pooled meta-analysis to investigate the diagnostic performance of CEUS in the evaluation of SRMs confirmed by pathology. A SR up to April 2022 was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The diagnostic performance of CEUS was evaluated basing on malignant vs. benign SMRs. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) from eligible studies were pooled, and summary receiver operating characteristic (SROC) curves were constructed for each endpoint. Overall, five qualified studies were deemed suitable for this meta-analysis. Finally, diagnostic performance of CEUS showed an accuracy of 0.93 in detecting malignant masses (sensitivity of 0.94, PPV of 0.95, specificity of 0.78, and NPV of 0.73). Taken together, CEUS may represent a promising minimally invasive diagnostic tool for characterization of SMRs, since it allows clinicians to identify malignant lesions.

Contrast enhancement for ultrasound-guided interventions: when to use it and what to expect?

The use of contrast-enhanced ultrasonography (CEUS) has recently become synonymous with high-standard ultrasonography (US). From expanding the reach of US diagnostics to improving the precision of various invasive procedures, CEUS is rapidly becoming a standard in numerous niches. However, proficiency in CEUS comes with a cost, both from a learning curve and material standpoint, and as every growing field, lacks firm evidence and standardization. Therefore, in the current paper, we aim to provide an evidence-based review of available methods and to discuss the advantages and pitfalls of CEUS in interventional procedures, trying to provide strong evidence whenever available, or at least an educated expert opinion if data are lacking.

Ablation Difficulty Score: Proposal of a new tool to predict success rate of percutaneous ablation for hepatocarcinoma

PURPOSE

Identify the factors related to failure ablation after percutaneous ultrasound guided single electrode radiofrequency ablation (RFA) for hepatocarcinoma (HCC) and propose a score for improving patient selection and treatment allocation.

METHODS

From 2010 to 2020 585 HCC nodules treated with RFA were prospectively collected. Ablation Difficulty Score (ADS) was built-up according to clinical and radiological factors related to failure ablation identified by Cox-logistic regression analysis. The study population was stratified in low risk (ADS 0), intermediate risk (ADS 1), and high risk (ADS ≥ 2) of failure ablation.

RESULTS

Overall ablation success rate was 85.5%. Morbidity and mortality rates were 3.5% and 0.0%. According to per nodule analysis the following factors resulted related to failure ablation: size > 20 mm (p = 0.002), sub-capsular location (p = 0.008), perivascular location (p = 0.024), isoechoic appearance (p = 0.008), and non-cirrhotic liver (p = 0.009). The ablation success rate was 93.5% in ADS 0, 85.8% in ADS 1 and 71.3% in ADS ≥ 2 (p < 0.001). The 1-year local tumor progression (LTP) free survival was 90.2% in ADS 0, 80.6% in ADS 1, and 72.3% in ADS ≥ 2 (p = 0.009). Nodule's size > 20 mm (p = 0.014), isoechoic appearance (p = 0.012), perivascular location (p = 0.012) resulted related to lower LTP free survival.

CONCLUSION

Ablation Difficulty Score could be a simple and useful tool for guiding the treatment decision making of HCC. RFA in high risk nodules (ADS ≥ 2) should be carefully evaluated and reserved for patients not suitable for surgery or liver transplantation.