A Novel Method to Increase Tumor Ablation Zones With RFA by Injecting the Cationic Polymer Solution to Tissues: In Vivo and Computational Studies.

Objective: This study aims to examine, for the first time, the introduction of cationic polymer solutions to improve radiofrequency ablation (RFA) in terms of a potentially enlarged ablation zone.

Methods: By using in vivo and computational RFA studies, two cationic polymers, Chitooligosaccharides (COS) and carboxymethyl chitosan (CMC), diluted in deionized water, were injected into tissues separately surrounding the RF bipolar electrode prior to power application. A total of 9 rabbits were used to 1) measure the increase in electrical conductivity of tissues injected with the cationic polymer solutions, and 2) explore the enhancement of the ablation performance in RFA trials.

Tumor Ablation Enhancement by Combining Radiofrequency Ablation and Irreversible Electroporation: An In Vitro 3D Tumor Study.

We hypothesized and demonstrated for the first time that significant tumor ablation enhancement can be achieved by combining radiofrequency ablation (RFA) and irreversible electroporation (IRE) using a 3D cervical cancer cell model. Three RFA (43, 50, and 60 °C for 2 min) and IRE protocols (350, 700, and 1050 V/cm) were used to study the combining effect in the 3D tumor cell model. The in vitro experiment showed that both RFA enhanced IRE and IRE enhanced RFA can lead to a significant increase in the size of the ablation zone compared to IRE and RFA alone.

Design of a Novel Electrode of Radiofrequency Ablation for Large Tumors: In Vitro Validation and Evaluation.

In a prior study, we proposed a novel monopolar expandable electrode (MEE) for use in radiofrequency ablation (RFA). The purpose of our work was to now validate and evaluate this electrode using on in vitro experimental model and computer simulation. Two commercially available RF electrodes (conventional electrode (CE) and umbrella electrode (UE)) were used to compare the ablation results with the novel MEE using an in vitro egg white model and in vivo liver tumor model to verify the efficacy of MEE in the large tumor ablation, respectively.

Steerable catheters for minimally invasive surgery: a review and future directions.

The steerable catheter refers to the catheter that is manipulated by a mechanism which may be driven by operators or by actuators. The steerable catheter for minimally invasive surgery has rapidly become a rich and diverse area of research. Many important achievements in design, application and analysis of the steerable catheter have been made in the past decade.

Development of a statistical model for cervical cancer cell death with irreversible electroporation in vitro.

Purpose: The aim of this study was to develop a statistical model for cell death by irreversible electroporation (IRE) and to show that the statistic model is more accurate than the electric field threshold model in the literature using cervical cancer cells in vitro.

Methods: HeLa cell line was cultured and treated with different IRE protocols in order to obtain data for modeling the statistical relationship between the cell death and pulse-setting parameters. In total, 340 in vitro experiments were performed with a commercial IRE pulse system, including a pulse generator and an electric cuvette.

A new approach to feedback control of radiofrequency ablation systems for large coagulation zones.

Aim: The aim of this study was to investigate the feasibility of achieving relatively large coagulation zones (i.e. ≥3 cm in diameter) with radiofrequency ablation (RFA) by using a broad control system.

Numerical analysis of the relationship between the area of target tissue necrosis and the size of target tissue in liver tumours with pulsed radiofrequency ablation.

Purpose: Radiofrequency ablation (RFA) is currently restricted to the treatment of target tissues with a small size (<3 cm in diameter). To overcome this problem with RFA, some phenomena need to be understood first. The study presented in this paper investigated the relationship between the area of target tissue necrosis (TTN) and the size of target tissue in pulsed radiofrequency ablation (PRFA).

Small vessel disease/white matter disease of the brain and its association with osteoporosis.

Background: Evidence now suggests the role of neural effect on bone mass control. The effect of small vessel disease of the brain on osteoporosis has not been studied. The aim of this study was to investigate the association of white matter disease (WMD) of the brain with osteoporosis in the elderly.

Study of the relationship between the target tissue necrosis volume and the target tissue size in liver tumours using two-compartment finite element RFA modelling.

Purpose: The aim of this study was to investigate the relationship between the target tissue necrosis volume and the target tissue size during the radiofrequency ablation (RFA) procedure.

Materials And Methods: The target tissues with four different sizes (dxy = 20, 25, 30 and 35 mm) were modelled using a two-compartment radiofrequency ablation model. Different voltages were applied to seek the maximum target tissue necrosis volume for each target tissue size.

Evaluation of the current radiofrequency ablation systems using axiomatic design theory.

This article evaluates current radiofrequency ablation systems using axiomatic design theory. Due to its minimally invasive procedure, short-time hospital stay, low cost, and tumour metastasis treatment, the radiofrequency ablation technique has been playing an important role in tumour treatment in recent decades. Although the radiofrequency ablation technique has many advantages, some issues still need to be addressed.

White matter disease severity of the brain and its association with geriatric syndromes.

Background And Aim: White matter disease (WMD) of the brain is considered to be secondary to small vessel ischemia and can be a single unifying risk factor for the development of geriatric syndromes. The aim of our study was to investigate the association of the global and regional severity of WMD in the brain with geriatric syndromes burden.

Methods: In our retrospective study, consecutive outpatient charts from patients seen between January 2010 and June 2011 at University of Alberta Hospital Seniors Clinic were reviewed.

Modeling and in vitro experimental validation for kinetics of the colonoscope in colonoscopy.

Colonoscopy is the most sensitive and specific means for detection of colon cancers and polyps. To make colonoscopy more effective several problems must be overcome including: pain associated with the procedure, the risk of perforation, and incomplete intubation colonoscopy. Technically, these problems are the result of loop formation during colonoscopy.

Methicillin-resistant Staphylococcus aureus: implications for the radiology department.

Objective: The purpose of this article is to discuss some of the implications of methicillin-resistant Staphylococcus aureus (MRSA) for the radiology department.

Conclusion: MRSA is an infectious organism that has been increasing in prevalence and has presented a challenge to hospitals worldwide due to its drug resistance and propensity to cause serious infections. The radiology department is a site of high patient traffic and regularly encounters MRSA-positive patients.

Idiopathic infantile arterial calcification in a 12-year-old girl presenting as chronic mesenteric ischemia: imaging findings and angioplasty results.

We report an unusual case of chronic mesenteric ischemia presenting in a 12-year-old girl with idiopathic infantile arterial calcinosis (IIAC). This is the first reported case in the literature of chronic mesenteric ischemia in the setting of IIAC. The girl presented with a classical history of postprandial abdominal pain.