Assessing the impact and resource implications of contrast-enhanced ultrasound on workflow of patients with incidental focal liver lesions on the UK national health service.

Background: Focal liver lesions (FLL) are abnormal growths that require timely identification. Contrast-enhanced ultrasound (CEUS) is a cost-effective imaging modality for characterising FLL with similar sensitivity to computed tomography (CT) and magnetic resonance imaging (MRI). Despite being recommended by NICE, its adoption within the national health service (NHS) is limited due to low clinical demand, limited referral, and lack of knowledge. Purpose: To evaluate the impact of CEUS on patients with incidental FLL and assess the resource implications of introducing CEUS as a diagnostic service within the NHS. Material and methods: A patient flow review and cost-minimisation analysis were conducted. This involved a targeted literature review, NHS Trust stakeholder consultations, and development of a Microsoft Excel cost-minimisation model to explore potential value of CEUS use versus CT and MRI by episode. A scenario analysis of the base-case explored increasing CEUS use to 50% and 90%. A sensitivity analysis was performed to assess how changes in assumptions impacted the model and the resulting cost estimates. Results: The model, comparing a world with and without CEUS, showed that current use (base-case: 5%) resulted in cost savings of £224,790/year. The sensitivity analysis indicated that regardless of changes to the assumptions, CEUS still resulted in cost savings to the NHS. By increasing CEUS use to 50% and 90%, cost savings of up to £2,247,894/year and £4,046,208/year could be achieved, respectively. Conclusion: By standardising CEUS use for characterising FLL, substantial cost savings could be realised, whilst reducing wait times and expanding diagnostic capacity, thus preserving limited CT and MRI capacity for high-priority cases.

Ultrasound-guided motor unit scanning electromyography.

INTRODUCTION/AIMS: Measuring the spatial dimensions of a single motor unit remains a challenging problem, and current techniques, such as scanning electromyography (EMG), tend to underestimate the true dimensions. In this study we aimed to estimate more accurately the dimensions of a single motor unit by developing a clinically applicable scanning EMG protocol that utilizes ultrasound imaging to visualize and target a transect through the center of a single motor unit. METHODS: Single motor unit twitches in the tibialis anterior muscles of healthy volunteers were elicited via stimulation of the fibular nerve, visualized with ultrasound, and targeted with an intramuscular EMG electrode. The electrode was moved by hand in small steps through the motor unit territory. Ultrasound video output was synchronized to EMG capture, and the needle position was tracked at each step. RESULTS: Eight recordings from six participants were collected. The technique was quick and easy to perform (mean time, 6.1 minutes) with reasonable spatial resolution (mean step size, 1.85 mm), yielding motor unit territory sizes between 1.53 and 14.65 mm (mean, 7.15 mm). DISCUSSION: Ultrasound-guided motor unit scanning EMG is a quick and accurate method for obtaining a targeted motor unit transect. This combination of two readily available clinical tools provides insights into the dimensions and internal structure of the motor unit as a marker for neuromuscular conditions.

Novel delivery of cellular therapy to reduce ischemia reperfusion injury in kidney transplantation.

Ex vivo normothermic machine perfusion (NMP) of donor kidneys prior to transplantation provides a platform for direct delivery of cellular therapeutics to optimize organ quality prior to transplantation. Multipotent Adult Progenitor Cells (MAPC® ) possess potent immunomodulatory properties that could minimize ischemia reperfusion injury. We investigated the potential capability of MAPC cells in kidney NMP. Pairs (5) of human kidneys, from the same donor, were simultaneously perfused for 7 hours. Kidneys were randomly allocated to receive MAPC treatment or control. Serial samples of perfusate, urine, and tissue biopsies were taken for comparison. MAPC-treated kidneys demonstrated improved urine output (P = .009), decreased expression of injury biomarker NGAL (P = .012), improved microvascular perfusion on contrast-enhanced ultrasound (cortex P = .019, medulla P = .001), downregulation of interleukin (IL)-1ß (P = .050), and upregulation of IL-10 (P < .047) and Indolamine-2, 3-dioxygenase (P = .050). A chemotaxis model demonstrated decreased neutrophil recruitment when stimulated with perfusate from MAPC-treated kidneys (P < .001). Immunofluorescence revealed prelabeled MAPC cells in the perivascular space of kidneys during NMP. We report the first successful delivery of cellular therapy to a human kidney during NMP. Kidneys treated with MAPC cells demonstrate improvement in clinically relevant parameters and injury biomarkers. This novel method of cell therapy delivery provides an exciting opportunity to recondition organs prior to transplantation.

Percutaneous Irreversible Electroporation (IRE) of Hepatic Malignancy: A Bi-institutional Analysis of Safety and Outcomes.

AIM: Irreversible electroporation (IRE) is a non-thermal ablative option in patients unsuitable for standard thermal ablation, due to its potential to preserve collagenous structures (vessels and ducts) and a reduced susceptibility to heat sink effects. In this series from two large tertiary referral hepatobiliary centres, we aim to assess the safety/outcomes of hepatic IRE. MATERIALS AND METHODS: Bi-institutional retrospective, longitudinal follow-up series of IRE for primary hepatic malignancy; [hepatocellular carcinoma (n = 20), cholangiocarcinoma (n = 3)] and secondary metastatic disease; colorectal (n = 28), neuroendocrine (n = 1), pancreatic (n = 1), breast (n = 1), gastrointestinal stromal tumour (GIST, n = 1) and malignant thymoma (n = 1). Outcome measures included procedural safety/effectiveness, time to progression and time to death. RESULTS: Between 2013 and 2017, 52 patients underwent percutaneous IRE of 59 liver tumours in 53 sessions. All tumours were deemed unsuitable for thermal ablation. Cases were performed using ultrasound (US) or computed tomography (CT) guidance. A complete ablation was achieved in n = 44, (75%) of cases with an overall complication rate of 17% (n = 9). Of the complete ablation group, median time to progression was 8 months. At 12 months, 44% were progression-free (95% CI 30-66%). The data suggest that larger lesion size (> 2 cm) is associated with shorter time to progression and there is highly significant difference with faster time to progression in mCRC compared with HCC. Median survival time was 38 months. CONCLUSION: This bi-institutional review is the largest UK series of IRE and suggests this ablative technology can be a useful tool, but appears to mainly induce local tumour control rather than cure with HCC having better outcomes than mCRC.

The prevalence and significance of renal perfusion defects in early kidney transplants quantified using 3D contrast enhanced ultrasound (CEUS).

OBJECTIVES: Vascular complications are one of the most common causes of early kidney transplant dysfunction. Contrast enhanced ultrasound increases sensitivity to vascular changes. The aim of this study was to assess the prevalence and size of vascular abnormalities in early renal transplants using 3D CEUS and the significance of perfusion defects on renal function. METHODS: Ninety-nine renal transplant patients underwent 3D CEUS after surgery to quantify perfusion defects as percentage total renal volume (TRV). Serum creatinine and estimated glomerular filtration rate (eGFR) were recorded up to 3 months post-surgery. RESULTS: Twenty participants had focal perfusion defects (0.2-43%TRV). There was a meaningful difference in patients with perfusion defects in eGFR at 1 month (90% CI 2.7-19.2 mL/min/1.73 m2) and 3 months (90% CI 1.9-19.6 mL/min/1.73 m2) and creatinine at 3 months (90% CI -56 - -8 µmol/L) using a predetermined clinical threshold. Perfusion defect size correlated well with both serum creatinine and eGFR at 3 months (R = 0.80, p ≤ 0.000 and 0.58, p = 0.038). No correlation was seen prior to 3 months. CONCLUSIONS: Perfusion defects in kidney transplants were more common than expected and were highly likely to reduce renal function at 1-3 months, and the size of the defect affected the degree of functional change at 3 months. KEY POINTS: • Perfusion defects were more common than previously thought. • Perfusion defects could be quantified using 3D CEUS. • The presence of even small perfusion defects may affect kidney function. • Size of perfusion defects correlated with subsequent kidney function at 3 months. • Potentially useful in informing clinician expectations of kidney function post-surgery.

Intrarenal arteriovenous shunts in kidney transplants demonstrated by contrast-enhanced ultrasound.

The kidney can undergo several hemodynamic changes in response to physiological stressful conditions. Arteriovenous (AV) shunting is an example where renal blood flow is redistributed away from the cortex toward the metabolically vulnerable medulla. Identification of this phenomenon is important as it may reflect underlying pathology. Despite evidence of renal AV shunting, its existence has been questioned. To our knowledge, this case series demonstrates for the first time the presence of renal AV shunting using contrast enhanced ultrasound.

Can live bi-plane sonography reduce work-related musculoskeletal disorders of the wrist?

OBJECTIVES: Work-related musculoskeletal disorders (WMSDs) are a recognized problem affecting up to 81% of sonographers. Live bi-plane imaging is a new technology derived from matrix transducers, which allows the operator to scan in more than one plane simultaneously and can reduce the off-axis movement of the scanning arm when assessing abdominal organs. This study was performed to assess if using a bi-planar technique would reduce stressful movements of the wrist. METHODS: Twelve patients were scanned by three operators (four each) using both a standard scanning abdominal protocol and a live bi-plane abdominal protocol using an iu22 scanner (Philips Healthcare, Bothell, WA) and an X6-1 probe with a bi-axial flexible electrogoniometer measuring the postural stresses on the scanning wrist throughout the study. RESULTS: Significant flexion/extension and radial/ulnar deviations were markedly reduced using the bi-plane scanning protocol compared to the standard B-mode protocol, with an average reduction in significant repetitive wrist movements of 71.6% (p = <0.001). CONCLUSIONS: Bi-planar ultrasound scanning technique may reduce stressful movements on the scanning arm and might reduce the likelihood of WMSD assuming there are no other contributing factors.

Diagnosis of gallbladder problems using three-dimensional ultrasound.

OBJECTIVE: The purpose of this study was to determine whether offline reported three-dimensional ultrasound (3DUS) is as accurate as standard two-dimensional ultrasound (2DUS) with regard to demonstrating gallbladder disease. METHOD: The cohort comprised 80 consecutive patients referred for an abdominal ultrasound examination. The participants underwent routine 2DUS assessment of the gallbladder followed by the acquisition of two 3DUS volumes of the region of the gall bladder. The two techniques were reported independently of each other, and the diagnoses were compared for correlation. RESULTS: There was overall agreement of the two techniques in 89% of cases with a positive predictive value of 89%, negative predictive value of 91% and a specificity of 86%. Small polyps (sub-4 mm) were the only positive discrepancies. Cohen's kappa found that there was substantial agreement between the two techniques (p = 0.05 for a two-tailed kappa 0.67), and chi-squared test found no significant difference in diagnoses (p = 0.95). CONCLUSION: This study shows that 3DUS diagnosis correlates well with 2DUS with regard to most gallbladder problems and could be sufficient as a stand-alone technique.