Versatile utilization of real-time intraoperative contrast-enhanced ultrasound in cranial neurosurgery: technical note and retrospective case series.

OBJECTIVE: Intraoperative contrast-enhanced ultrasound (iCEUS) offers dynamic imaging and provides functional data in real time. However, no standardized protocols or validated quantitative data exist to guide its routine use in neurosurgery. The authors aimed to provide further clinical data on the versatile application of iCEUS through a technical note and illustrative case series. METHODS: Five patients undergoing craniotomies for suspected tumors were included. iCEUS was performed using a contrast agent composed of lipid shell microspheres enclosing perflutren (octafluoropropane) gas. Perfusion data were acquired through a time-intensity curve analysis protocol obtained using iCEUS prior to biopsy and/or resection of all lesions. RESULTS: Three primary tumors (gemistocytic astrocytoma, glioblastoma multiforme, and meningioma), 1 metastatic lesion (melanoma), and 1 tumefactive demyelinating lesion (multiple sclerosis) were assessed using real-time iCEUS. No intraoperative complications occurred following multiple administrations of contrast agent in all cases. In all neoplastic cases, iCEUS replicated enhancement patterns observed on preoperative Gd-enhanced MRI, facilitated safe tumor debulking by differentiating neoplastic tissue from normal brain parenchyma, and helped identify arterial feeders and draining veins in and around the surgical cavity. Intraoperative CEUS was also useful in guiding a successful intraoperative needle biopsy of a cerebellar tumefactive demyelinating lesion obtained during real-time perfusion analysis. CONCLUSIONS: Intraoperative CEUS has potential for safe, real-time, dynamic contrast-based imaging for routine use in neurooncological surgery and image-guided biopsy. Intraoperative CEUS eliminates the effect of anatomical distortions associated with standard neuronavigation and provides quantitative perfusion data in real time, which may hold major implications for intraoperative diagnosis, tissue differentiation, and quantification of extent of resection. Further prospective studies will help standardize the role of iCEUS in neurosurgery.

Unintentionally retained vascular devices: improving recognition and removal.

The increased demand for minimally invasive placement of intravascular medical devices has led to increased procedure-related complications, including retention of all or part of the implanted device. A number of risk factors can predispose to unintentionally retained vascular devices (uRVD); most are technical in etiology. Despite best efforts to insert and remove vascular devices properly, uRVD still occur. Prevention or early identification of uRVD is ideal; however, procedural complications are not always recognized at the time of device insertion or removal. In these cases, early radiologic diagnosis is important to enable expeditious removal and reduction of morbidity, mortality, and medicolegal consequences. The diagnostic radiologist's role is to identify suspected uRVD and ensure proper communication of the findings to the referring clinician. The diagnostic radiologist can implement various strategies to increase detection of uRVD and advise the referring clinician regarding the use of minimally invasive percutaneous techniques for safe removal of uRVD.

Intra-arterial contrast-enhanced ultrasound (IA CEUS) for localization of hepatocellular carcinoma (HCC) supply during transarterial chemoembolization (TACE): a case series.

Transarterial chemoembolization (TACE) is a proven catheter-based locoregional therapy for treatment of hepatocellular carcinoma (HCC). Drug-eluting bead TACE involves delivering micrometer-sized particles preloaded with doxorubicin directly to the tumor via its arterial blood supply and results in vascular embolization with intra-tumoral drug release. Effective therapy requires mapping of the tumor arterial supply, which in some cases cannot be accomplished with conventional angiographic techniques alone. Contrast-enhanced ultrasound (CEUS) is an imaging technique which utilizes microbubble contrast agents to demonstrate blood flow and tissue perfusion, enabling tumor visualization in real time. CEUS with intravenous contrast administration is well established for evaluation of HCC. Intra-arterial (IA) CEUS, on the other hand, is an emerging technique that allows more selective evaluation of the arterial supply to the tumor. The three cases in this report illustrate the utility of intra-procedural IA CEUS during TACE. Specifically, IA CEUS aided TACE in cases where the HCC showed poor arterial enhancement, an extrahepatic arterial supply, and a portal venous supply, respectively.

Abdominal radiograph pearls and pitfalls for the emergency department radiologist: a pictorial review.

Abdominal plain films are often the first imaging examination performed on a patient with abdominal pain in the emergency department. Radiograph findings can help guide clinical management and the need for advanced imaging. A pictorial review of a range of abdominal radiograph findings is presented, including bowel gas patterns, abdominal organ evaluation, pathologic gas, calcifications, implanted devices, and foreign bodies.

Role of contrast-enhanced ultrasound (CEUS) in evaluation of thermal ablation zone.

PURPOSE: Thermal ablation has emerged as a mainstay therapy for primary and metastatic liver malignancy. Percutaneous thermal ablation is usually performed under CT and/or ultrasound guidance. CT guidance frequently utilizes iodinated contrast for tumor targeting, with additional radiation and contrast required at the end of the procedure to ensure satisfactory ablation margins. Contrast-enhanced ultrasound (CEUS) is an imaging technique utilizing microbubble contrast agents to demonstrate blood flow and tissue perfusion. In this study, we performed a retrospective review to assess the utility of CEUS in the immediate post ablation detection of residual tumor. METHODS: Sixty-four ablations were retrospectively reviewed. 6/64 ablations (9.4%) had residual tumor on the first follow-up imaging after thermal ablation. There were two groups of patients. Group 1 underwent standard protocol thermal ablation with CT and/or ultrasound guidance. Group 2 not only had thermal ablation with a protocol identical to group 1, but also had CEUS assessment at the conclusion of the procedure to ensure satisfactory ablation zone. RESULTS: The residual tumor rate in group 1 was 16.7% and the residual tumor rate in group 2 was 0%. The difference between the groups was statistically significant with a p value of 0.023. The results suggest that using CEUS assessment immediately after the ablation procedure reduces the rate of residual tumor after thermal ablation. CONCLUSION: CEUS evaluation at the end of an ablation procedure is a powerful technique providing critical information to the treating interventional radiologist, without additional nephrotoxic contrast or ionizing radiation.

Multicenter Prospective Clinical Series Evaluating Radiofrequency Ablation in the Treatment of Painful Spine Metastases.

BACKGROUND: Radiofrequency ablation (RFA) of vertebral body metastases (VBM) has been reported as safe and effective in retrospective studies. This single-arm prospective multicenter clinical study evaluates RFA in the treatment of painful VBM. METHODS: Fifty patients with VBM were prospectively enrolled during a 13-month period at eight US centers under an IRB-approved study. Percutaneous RFA was performed under imaging guidance with cement augmentation at the discretion of the operator. Pain, disability and quality of life were evaluated at baseline, prior to discharge, days 3, 7, 30 and 90 using the Numerical Pain Rating Scale, Oswestry Disability Index (ODI), the Functional Assessment of Cancer Therapy-General 7 (FACT-G7) and Functional Assessment of Cancer Therapy Quality-of-Life Measurement in Patients with Bone Pain (FACT-BP). Adverse events were monitored throughout this time interval. RESULTS: Twenty-six male and 24 female patients (mean age 61.0) underwent 69 treatments (30 thoracic and 39 lumbar). Cement augmentation was performed in 96 % of reported levels. Significant improvement in mean scores for pain, disability and cancer-specific health-related quality of life from baseline to all time intervals was seen. NRPS improved from 5.9 to 2.1 (p < 0.0001). ODI improved from 52.9 to 37.0 (p < 0.08). FACT-G7 improved form 10.9 to 16.2 (p = 0.0001). FACT-BP improved from 22.6 to 38.9 (p < 0.001). No complications related to the procedure were reported. CONCLUSION: RFA with cement augmentation safely and effectively reduces pain and disability rapidly, while increasing quality of life in patients suffering from vertebral body metastases.