Feasibility and Usefulness of Intra-Cavitary Contrast-Enhanced Ultrasound in Percutaneous Nephrostomy

Intracavitary Applications for CEUS in PTCD

Intracavitary contrast-enhanced ultrasound is widely accepted as a highly informative, safe, and easily reproducible technique for the diagnosis, treatment, and follow-up of different pathologies of the biliary tree. This review article describes the diverse applications for CEUS in intracavitary biliary scenarios, supported by a literature review of the utilization of the method in indications like biliary obstruction by various etiologies, including postoperative strictures, evaluation of the biliary tree of liver donors, and evaluation of the localization of a drainage catheter. We also provide pictorial examples of the authors' personal experience with the use of intracavitary CEUS in cases of PTCD as a palliative intervention. Intracavitary CEUS brings all the positive features of US together with the virtues of contrast-enhanced imaging, providing comparable accuracy to the standard techniques for diagnosing biliary tree diseases.

Ultrasound contrast agent assisted ultrasonography guidance percutaneous nephrostomy for non-hydronephrotic kidney

BACKGROUND

Given the limited success rate and considerable challenges associated with conventional ultrasonography (US) guidance for percutaneous nephrostomy (PCN) in non-hydronephrotic kidneys, this study proposed a solution with ultrasound contrast agent to enhance the success rate and mitigate the difficulties.

MATERIALS AND METHODS

From January 2017 to August 2023, a total of thirteen patients diagnosed with non-hydronephrotic kidney were included in the study. Following routine ultrasonography examination, no significant dilatation of the renal collecting system was observed. US-guided percutaneous nephrostomy PCN was performed with the assistance of ultrasound contrast agent (UCA). The patients were subsequently monitored to assess the improvement of symptoms and postoperative recovery.

RESULTS

The success rate was found to be 100% for all patients (13/13) and kidneys (20/20). The average volume of UCA solution used was 19 ± 6.7 mL (range, 11-35 mL), while the mean duration of the operation was 18.92 ± 8.96 min (range, 7-36 min). A majority of the patients (12/13) underwent a single puncture procedure. Throughout the follow-up period, no serious complications were observed, and surgery resulted in significant alleviation of symptoms in all patients.

CONCLUSION

The use of UCA-assisted US guidance PCN has been shown to be effective in achieving urinary diversion and alleviating associated clinical symptoms in non-hydronephrotic kidneys. In comparison to traditional methods, this approach demonstrates a high success rate and safety profile, while also offering a simplified operative procedure. Consequently, it presents a novel method and concept for managing non-hydronephrotic kidneys afflicted by urine leakage.

Contrast-enhanced ultrasound versus conventional ultrasound-guided percutaneous nephrolithotomy in patients with a non-dilated collecting system: results of a pooled analysis of randomized controlled trials

BACKGROUND

Contrast-enhanced ultrasound in percutaneous nephrolithotomy (CEUS-PCNL) is an economical and practical technique for the treatment of patients with renal stones without significant collecting system dilatation. The aim of this systematic review is to compare the safety and efficacy of CEUS-PCNL and conventional ultrasound (US)-guided (US-PCNL) treatment of patients with renal calculi without significant hydronephrosis.

METHODS

This review was conducted with strict adherence to the PRISMA guidelines. Comparative studies on CEUS-PCNL and US-PCNL published in PubMed, SinoMed, Google Scholar, Embase, and Web of science until March 1, 2023, were systematically searched. RevMan 5.1 software was used for meta-analysis. Pooled odds ratios (ORs), weight mean differences (WMDs) and standard mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using the fixed-effects or random-effects model. Publication bias was evaluated using funnel plots.

RESULTS

Four randomized controlled trials involving 334 patients (168 with CEUS-guided PCNL and 166 with US-guided PCNL) were identified. There was no statistically significant difference between CEUS-guided PCNL and US-guided PCNL in terms of the operation time (SMD: - 0.14; 95% CI - 0.35 to 0.08; p = 0.21), minor complications (p = 0.48), major complications (p = 0.28) and overall complications (p = 0.25). However, CEUS-guided PCNL had a higher stone-free rate (OR: 2.22; 95% CI 1.2 to 4.12; p = 0.01), higher success rate of single-needle punctures (OR:3.29; 95% CI 1.82 to 5.95; p < 0.0001), shorter puncture time (SMD: - 1.35; 95% CI - 1.9 to - 0.79; p < 0.00001), shorter hospital stay (SMD: - 0.34; 95% CI - 0.55 to - 0.12; p = 0.002) and lesser hemoglobin loss (SMD: - 0.83; 95% CI - 1.06 to - 0.61; p < 0.00001) as compared with conventional US-guided PCNL.

CONCLUSIONS

According to almost all pooled data, CEUS-guided PCNL is superior to US-guided PCNL in terms of the perioperative outcomes. However, many rigorous clinical randomized controlled studies are required to obtain more accurate results. Registration The study protocol was registered with PROSPERO (CRD42022367060).

Contrast-Enhanced Ultrasonography Value for Early Prediction of Delayed Graft Function in Renal Transplantation Patients

OBJECTIVES

Delayed graft function (DGF) is a common early complication after kidney transplantation. The aim of the present study was to evaluate the value of contrast-enhanced ultrasonography (CEUS) in the early prediction of DGF after kidney transplantation.

METHODS

A total of 89 renal transplant recipients were retrospectively enrolled and divided into DGF group or normal graft function (NGF) group according to the allograft function. Conventional Doppler ultrasound and CEUS examination data on the first postoperative day were collected and analyzed.

RESULTS

The resistive indices of segmental and interlobar artery in the DGF group were significantly higher than those in the NGF group (0.71 ± 0.17 versus 0.63 ± 0.08, P = .006; 0.70 ± 0.16 versus 0.62 ± 0.08, P = .004, respectively). The patients experiencing DGF had significantly lower PI-c (14.7 dB ± 6.1 dB versus 18.5 dB ± 3.3 dB, P = .001) and smaller AUC-c (779.8 ± 375.8 dB·seconds versus 991.0 ± 211.7 dB·seconds, P = .003), as well as significantly lower PI-m (12.6 dB ± 5.9 dB versus 15.9 dB ± 3.9 dB, P = .006), shorter MTT-m (30.7 ± 9.4 seconds versus 36.3 ± 7.1 seconds, P = .01), and smaller AUC-m (P = .007). Multivariate analysis demonstrated that PI-c, AUC-c, and MTT-m were independent risk factors for DGF. The area under the receiver operating characteristic curve values of the combined predicted value (PI-c + MTT-m, PI-c + AUC-c + MTT-m) of DGF incidence were bigger than that of PI-c, AUC-c, or MTT-m.

CONCLUSIONS

CEUS parameters of the cortex and medulla have a good value for an early prediction of DGF after renal transplantation.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

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.

Emergency Decompression of Obstructive Uropathy Using Percutaneous Nephrostomy: Disease Pattern and Treatment Outcome at Two Urology Centers in Ethiopia

PURPOSE

Obstructive uropathy (OU) is a potentially life-threatening urologic emergency that requires urgent decompression. Percutaneous nephrostomy (PCN) is a commonly performed procedure to decompress OU. The objective of this study is to assess disease patterns and treatment outcome at two urologic centers in Ethiopia.

METHODS

A cross-sectional study was conducted on 110 patients who underwent emergency PCN from October 1, 2019 to September 30, 2020. Data were collected by a retrospective chart review. SPSS 25 was used for analysis. Descriptive statistics and logistic regression were utilized to assess disease pattern and significant predictors. A p-value of <0.05 on multivariate logistic regression was considered statistically significant.

RESULTS

Females accounted for 70% of cases and mean age at presentation was 48 ± 12.9 years. Bilateral OU was diagnosed in 60% of patients and 77.3% of obstructions occurred at the level of the ureter. Malignancies were diagnosed in >80% of patients among which cervical cancer was the commonest (37.3%) followed by bladder cancer (17.3%). Acute kidney injury (AKI) accounted for 70% of the presenting indications for PCN. Success rate after emergency PCN was 75.5% and 41.8% of the cases developed post-procedure complications. Factors that predicted successful outcome include male gender [AOR = 5.72 (1.13-28.92), 95% CI; p = 0.035], severe hydronephrosis pre-operatively [AOR = 7.12 (1.32-38.45), 95% CI; p = 0.022], and use of combined imaging (ultrasound and fluoroscope) to guide PCN [AOR = 12.91 (1.13-46.54), 95% CI; p = 0.039]. On the other hand, postoperative complication is a negative predictor [AOR = 0.26 (0.08-0.86), 95% CI; p = 0.027].

CONCLUSION

In this study, overall success of emergency PCN is low. Presence of severe hydronephrosis predicts technical ease and better outcome of PCN. Procedures performed under ultrasound and fluoroscope guidance also improve outcome. Postoperative complication rate is high in this study and mandates strict preventive measures as it predicts unfavorable outcome.

[Standardized contrast-enhanced ultrasound (CEUS) in clinical acute and emergency medicine and critical care (CEUS Acute) : Consensus statement of DGIIN, DIVI, DGINA, DGAI, DGK, ÖGUM, SGUM and DEGUM]

The present document describes the possible applications of contrast-enhanced ultrasound (CEUS) in emergency examinations. Guidelines on contrast medium ultrasound in acute and emergency care and intensive care medicine have not yet been published. Evidence-based CEUS guidelines were first provided by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and the World Federation for Ultrasound in Medicine and Biology (WFUMB). The presented recommendations describe the possible applications and protocols of CEUS in acute care.

Deep-learning-aided forward optical coherence tomography endoscope for percutaneous nephrostomy guidance

Percutaneous renal access is the critical initial step in many medical settings. In order to obtain the best surgical outcome with minimum patient morbidity, an improved method for access to the renal calyx is needed. In our study, we built a forward-view optical coherence tomography (OCT) endoscopic system for percutaneous nephrostomy (PCN) guidance. Porcine kidneys were imaged in our experiment to demonstrate the feasibility of the imaging system. Three tissue types of porcine kidneys (renal cortex, medulla, and calyx) can be clearly distinguished due to the morphological and tissue differences from the OCT endoscopic images. To further improve the guidance efficacy and reduce the learning burden of the clinical doctors, a deep-learning-based computer aided diagnosis platform was developed to automatically classify the OCT images by the renal tissue types. Convolutional neural networks (CNN) were developed with labeled OCT images based on the ResNet34, MobileNetv2 and ResNet50 architectures. Nested cross-validation and testing was used to benchmark the classification performance with uncertainty quantification over 10 kidneys, which demonstrated robust performance over substantial biological variability among kidneys. ResNet50-based CNN models achieved an average classification accuracy of 82.6%±3.0%. The classification precisions were 79%±4% for cortex, 85%±6% for medulla, and 91%±5% for calyx and the classification recalls were 68%±11% for cortex, 91%±4% for medulla, and 89%±3% for calyx. Interpretation of the CNN predictions showed the discriminative characteristics in the OCT images of the three renal tissue types. The results validated the technical feasibility of using this novel imaging platform to automatically recognize the images of renal tissue structures ahead of the PCN needle in PCN surgery.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

Comparison of contrast-enhanced ultrasound versus conventional ultrasound-guided percutaneous nephrolithotomy in patients with nondilated collecting system: a randomized controlled trial

OBJECTIVE

To compare the safety, effectiveness, and feasibility of contrast-enhanced ultrasound (CEUS) versus conventional ultrasound-guided percutaneous nephrolithotomy (PCNL) in patients with nondilated collecting system.

METHODS

Between July 2018 and July 2020, 160 kidney stone patients with nondilated collecting system planned for PCNL were randomly assigned into two groups, CEUS with retrograde ureteral contrast injection and conventional ultrasound with retrograde ureteral normal saline injection. Patient's demographics, the success rate of puncture, success rate of a single-needle puncture, number of punctures, puncture time, perioperative outcomes, stone-free rate, and incidence of complications were compared.

RESULTS

The success rate of a single-needle puncture for CEUS-guided PCNL was higher than that in the conventional ultrasound group (88.5% vs. 73.7%, p = 0.02). Patients performed with CEUS-guided PCNL required less needle passes (p = 0.02), shorter needle puncture time (p = 0.031), and shorter channel establishment time (p = 0.04) than those guided with conventional ultrasound. The postoperative hemoglobin decrease in the CEUS-guided PCNL group was less than that of the control group (p = 0.02). There was no significant difference in operating time, length of hospital stays, kidney function change, and complications between the two groups (p > 0.05). The 1-month stone-free rate was 94.9% in the CEUS group and 90.8% in the control group (p > 0.05).

CONCLUSIONS

Compared with conventional ultrasound, CEUS-guided PCNL may facilitate ultrasound-guided PCNL for patients without hydronephrosis, and benefited with a higher success rate of a single-needle puncture, less needle passes, shorter puncture time, and lower postoperative Hb drop.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR1800016981 KEY POINTS: • Compared with conventional ultrasound, CEUS-guided PCNL is a safe and efficacious procedure for kidney stone patients with nondilated collecting system. • Compared with conventional ultrasound, CEUS-guided PCNL benefited with a higher success rate of a single-needle puncture, less needle passes, shorter puncture time, and lower postoperative Hb drop. • CEUS-guided PCNL associated with the more accurate needle puncture and acceptable complications.

Impact of Implementing Contrast-Enhanced Ultrasound for Antegrade Nephrostogram After Percutaneous Nephrolithotomy

OBJECTIVES

To report results from a quality improvement (QI) project evaluating diagnostic performance, hospital resource use, and patient response data for postoperative contrast-enhanced ultrasound (CEUS) antegrade nephrostogram after percutaneous nephrolithotomy.

METHODS

For this Health Insurance Portability and Accountability Act-compliant, Institutional Review Board-approved study, QI data were deidentified and analyzed. On the first postoperative day after percutaneous nephrolithotomy, patients underwent both CEUS and fluoroscopic antegrade nephrostogram. For CEUS, 1.0 mL of Lumason (sulfur hexafluoride lipid type A microspheres; Bracco Diagnostics, Inc, Monroe Township, NJ) was injected via an indwelling nephrostomy tube, with ureteral patency confirmed by identifying intravesical ultrasound (US) contrast. Diagnostic performance for ureteral patency and contrast extravasation was calculated (with fluoroscopy as the reference standard). The examination time, room time, physician time, hospital costs, and patient response data were compared. The mean, standard deviation, 95% confidence interval, differences in mean, and 95% confidence interval of differences were calculated.

RESULTS

Eighty-one examinations were performed in 73 patients during the QI period. The sensitivity and specificity of CEUS for ureteral patency were 96% and 57%, respectively. There was no significant difference in time metrics between modalities, and the cost analysis showed lower direct and indirect costs for CEUS. Patient responses revealed lower levels of comfort for CEUS relative to fluoroscopy, without significant differences in reported pain or effort levels.

CONCLUSIONS

Contrast-enhanced US showed very high sensitivity for ureteral patency; the relatively low specificity may have resulted from false-negative results in fluoroscopy. The hospital costs and resource use of CEUS compared favorably to fluoroscopy. Contrast-enhanced US also offers inherent advantages, including portability and lack of ionizing radiation.

Assessment of the Contrast-Enhanced Ultrasound in Percutaneous Nephrolithotomy for the Treatment of Patients with Nondilated Collecting System

Purpose: To investigate the clinical value of contrast-enhanced ultrasound (CEUS) in percutaneous nephrolithotomy (PCNL) for kidney stone patients without hydronephrosis. Methods: Patients with nondilated collecting system kidney stones who underwent PCNL between October 2018 and December 2019 at our hospital were enrolled in this study. Patients who met the inclusion criteria were randomized into two groups: a CEUS-guided PCNL group and a conventional ultrasound (US)-guided PCNL group. The operation results of the two groups were compared, including the number of attempts for effective puncture, duration to effective puncture, stone clearance rate, blood loss, postoperative complications, and hospital stay. Results: Fifty-six patients with a nondilated collecting system who underwent PCNL for 60 kidneys were included in this study, including 4 patients who underwent bilateral PCNL due to bilateral renal stones. There were 30 kidneys in each group. All patients successfully underwent PCNL. The CEUS-guided PCNL group had more accurate punctures, with a higher effective rate of one puncture and shorter puncture time. There was no statistically significant difference in stone clearance rate between the two groups. Four cases of double channels were established in the conventional US-guided PCNL group, while there was only one case in the CEUS-guided PCNL group. In the CEUS-guided PCNL group, most cases (96.7%, 29/30) had no or only mild complications, which were significantly better than the conventional US-guided PCNL group (76.7%, 23/30). The mean postoperative hemoglobin loss in the CEUS-guided PCNL group was 9.5 (range 1-25) g/L, which was significantly lower than 15.5 (range 5-52) g/L in the conventional US-guided PCNL group. Conclusion: The CEUS technique can improve visibility of the nondilated renal collecting system, facilitate selection of suitable calix, and identify renal calix fornix. It also benefits needle placement in patients with a nondilated collecting system.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

Contrast-Enhanced Ultrasound Guidance for Interventional Procedures

Since its introduction, contrast-enhanced ultrasound (CEUS) has gained an important role in the diagnosis and management of abdominal and pelvic diseases. Contrast-enhanced ultrasound can improve lesion detection rates as well as success rates of interventional procedures when compared to conventional ultrasound alone. Additionally, CEUS enables the interventionalist to assess the dynamic enhancement of different tissues and lesions, without the adverse effects of contrast-enhanced computed tomography, such as exposure to ionizing radiation and nephrotoxicity from iodinated contrast material. This review article describes the various applications and advantages of the use of CEUS to enhance performance of ultrasound-guided interventions in the abdomen and pelvis.

Contrast-enhanced ultrasound (CEUS) nephrostogram: utility and accuracy as an alternative to fluoroscopic imaging of the urinary tract

AIM

To establish the feasibility and accuracy of contrast-enhanced ultrasound (CEUS) nephrostogram in comparison to the reference standard, fluoroscopic nephrostogram, in providing alternative imaging of the urinary tract post-nephrostomy insertion.

MATERIALS AND METHODS

This prospective study was approved by the institutional and national ethics committee. All patients for whom a fluoroscopic nephrostogram was requested were included. Fluoroscopic and CEUS nephrostograms were performed within 24 hours. Image analysis (nephrostomy position, opacification of pelvicalyceal system, ureter, and bladder) was performed by two reviewers, and the diagnostic accuracy of the CEUS nephrostograms was compared to fluoroscopic nephrostograms.

RESULTS

Sixty-two nephrostograms were performed in 48 patients from June 2011 to April 2016, (male: 25/48, 52.1%; mean age 65 years, range 28-90 years). Indications for nephrostomy were: malignancy (29/62; 46.8%), benign ureteric stricture (14/62; 22.6%), urinary diversion (8/62; 12.9%), renal calculus (5/62; 8.1%), haematoma (3/62; 4.8%) or pelvi-ureteric junction obstruction (3/62; 4.8%). Two nephrostomies were identified as displaced by both techniques. The pelvicalyceal system was visualised in 60/60 (100%) examinations in both fluoroscopic and CEUS nephrostograms. The entire ureter was visualised in 30/60 (50%) with CEUS compared to 32/60 (53.3%) fluoroscopically. The distal ureter was the least well-visualised segment for both techniques with no significant difference (p=0.815). Both CEUS and fluoroscopy could be used to correctly identify complications including entero-ureteric fistula or urine leak. Fluoroscopic nephrostogram demonstrated drainage into the bladder in 33/60 (55%), CEUS confirmed drainage in 34/60 (56.7%) cases (p=0.317).

CONCLUSIONS

CEUS nephrostogram can determine the correct positioning of a nephrostomy and assess drainage into the bladder with statistically comparable results to fluoroscopy.

Use of Ultrasound Contrast Agents in Relation to Percutaneous Interventional Procedures: A Systematic Review and Pictorial Essay

The aim of this article is to provide an inventory of the use of contrast-enhanced ultrasound (CEUS) in relation to percutaneous interventional procedures. The article is structured into a systematic literature review followed by a clinical part relating to percutaneous CEUS-guided procedures. A literature search identified 3109 records. After abstract screening, 55 articles were analyzed and supplemented with pictorial material to explain the techniques. In conclusion, the best-evidenced indications for CEUS-guided interventions are biopsy and ablation of inconspicuous or B-mode-invisible tumors, intraprocedural ablation control and follow-up, as well as percutaneous transhepatic cholangiography and drainage procedures.

Contrast-enhanced ultrasound (CEUS) in abdominal intervention

The introduction of ultrasound contrast agents has rendered contrast-enhanced ultrasound (CEUS) a valuable complementary technique to address clinically significant problems. This pictorial review describes the use of CEUS guidance in abdominal intervention and illustrates such application for a range of clinical indications. Clinical application of CEUS discussed include commonly performed abdominal interventional procedures, such as biopsy, drainage, nephrostomy, biliary intervention, abdominal tumor ablation and its subsequent monitoring, and imaging of vascular complications following abdominal intervention. The purpose of this article is to further familiarize readers with the application of CEUS, particularly its specific strength over alternative imaging modalities, in abdominal intervention.

How to perform Contrast-Enhanced Ultrasound (CEUS)

"How to perform contrast-enhanced ultrasound (CEUS)" provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

Contrast-enhanced US-assisted Percutaneous Nephrostomy: A Technique to Increase Success Rate for Patients with Nondilated Renal Collecting System

Purpose To perform a single-center study of contrast material-enhanced ultrasonography (US)-assisted percutaneous nephrostomy (PCN) for patients with nondilated renal collecting system. Materials and Methods An international review board approved this retrospective study with waiver of informed consent for participation, and the study was approved by the Ethical Committee. From November 2011 to September 2015, 47 patients (mean age, 51.9 years ± 16.2 [standard deviation]; range, 18-80 years) with clinical necessity of urinary drainage, urinary diversion, or provision of access to the collecting system and with nondilated renal collecting system who underwent contrast-enhanced US-assisted PCN for 48 kidneys were included. US contrast agent was injected through the puncture needle and the drainage catheter to confirm successful PCN. The technical success rate and complications were evaluated. Relative frequencies with 95% confidence intervals (CIs) were calculated. Results The technical success rate was 100% (47 of 47, 95% CI: 93.8%, 100%) per patient and 100% (48 of 48, 95% CI: 94.0%, 100%) per kidney. For each kidney, the mean number of needle passes was 1.4 ± 0.5 (range, 1-3). The mean duration of the complete procedure was 18.9 minutes ± 4.8 (range, 8-30 minutes). The mean dose of contrast agent was 12.9 mL ± 3.2 (range, 8-25 mL). No major complications were observed. After a follow-up of 1-30 days (mean, 18.4 days ± 10.3), only four patients (four of 47, 8.5%, 95% CI: 2.37%, 20.4%) had minor complications, including one perirenal hematoma seen at US 9 days after the procedure and three patients with transient macroscopic hematuria that lasted 1-2 days. Conclusion Contrast-enhanced US-assisted PCN in patients with nondilated renal collecting system is valuable with high technical success rate. ^© RSNA, 2017.