Early clinical experience with a touchless image navigation interface for the endovascular suite.

Introduction: The inability to having comprehensive access to all pertinent imaging data related to an endovascular procedure in the sterile field is an unmet need, and its absence may have deleterious effects on decision-making, outcomes and workflow. Current image navigation solutions rely on traditional personal computing interfaces which are difficult to use in the sterile field. Innovative technological solutions are needed to address this need.Material and methods: Utilizing novel hardware and software integration, a human computer interaction (HCI) based platform has been developed through an iterative design and development process, that allows intuitive real-time access to imaging data in the sterile field. Following validation and pre-clinical testing, the platform has been introduced to the endovascular suite for clinical use.Results: Three prospective case-based observational reviews are presented that demonstrate the utility of touchless image navigation in the sterile field in facilitating decision-making and resource utilization during endovascular procedures, while avoiding the cognitive and workflow disturbances inherent in leaving the sterile field or involving non-scrubbed third persons in the image navigation process.Conclusion: Physician engagement and 'needs-based' technological innovation is needed to improve human computer interaction in the endovascular suite, in hopes of positively affecting procedural decision-making, outcomes, and workflow.

Pathophysiology of right ventricular failure in acute pulmonary embolism and chronic thromboembolic pulmonary hypertension: a pictorial essay for the interventional radiologist.

Pulmonary embolus (PE) is the third most common cause of cardiovascular death with more than 600,000 cases occurring in the USA per year. About 45% of patients with acute PE will have acute right ventricular failure, and up to 3.8% of patients will develop chronic thromboembolic pulmonary hypertension (CTEPH) with progressive, severe, chronic heart failure. The right ventricle (RV) is constructed to accommodate a low-resistance afterload. Increases in afterload from acute massive and submassive PE and CTEPH may markedly compromise the RV function leading to hemodynamic collapse and death. The purpose of this educational manuscript is to instruct on the pathophysiology of RV failure in massive and submassive PE and CTEPH. It is important to understand the pathophysiology of these diseases as it provides the rationale for therapeutic intervention by the Interventional Radiologist. We review here the pathophysiology of right ventricular (RV) failure in acute massive and submassive PE and CTEPH.

Retrievable Inferior Vena Cava Filters: A Tertiary Centre Perspective and Quality Assurance Study.

PURPOSE: To conduct a retrospective review and quality assurance study of inferior vena cava (IVC) filter retrieval over a two-year period at a tertiary care centre. METHODS: Patients who underwent IVC filter placement or retrieval over a two-year period were identified. Medical records were reviewed for patient characteristics, filter indication, time to filter retrieval, and complications. RESULTS: IVC filters were placed in 229 patients between January 1, 2015 and December 31, 2016. 113 retrievals were attempted and 101 filters were successfully retrieved (89.4%). Median time to first retrieval attempt was 48 days (range of 5-728). Seventy-one patients died in the interval after filter insertion before a retrieval attempt at a median time of 27 days (range of 3-430). In 17 patients, retrieval was complicated by or delayed because of penetration of IVC wall (n = 6), large thrombus burden trapped by filter (n = 5), filter tilt or migration (n = 3), and unclear reasons (n = 3). Time-to-first unsuccessful retrieval attempt was 141 days (median). Of all filters placed, 55.9% were never retrieved. Excluding deceased patients with in-situ filters (n = 71) and unsuccessful retrievals left in-situ as permanent filters (n = 5), there remains 52 patients (33%), with a median filter in-situ time of 488 days. CONCLUSION: Our study indicates that as many as 33% of patients may have been lost to follow-up of their in-situ IVC filter. Considering widespread reports of long-term complications and the recent safety alert issued by Health Canada, it is evident that a unified strategy is needed to track patients post filter insertion.

Half-dose gadobenate dimeglumine versus standard-dose gadodiamide in dynamic magnetic resonance imaging of non-cirrhotic livers: a retrospective intra-individual crossover comparison.

PURPOSE: The purpose of this study was to compare enhancement characteristics of half-dose gadobenate dimeglumine (0.05 mmol kg(-1)) with standard-dose gadodiamide (0.10 mmol kg(-1)), in the assessment of hepatic vessels and lesions, using retrospective intra-individual crossover comparison methodology. METHODS: Ethics committee approval was obtained. From 2004 to 2012, 21 patients underwent MRI examination with both standard-dose gadodiamide and half-dose gadobenate dimeglumine, using the same liver MRI protocol at 1.5 T. Eighteen patients whose scans showed no artifacts were selected. Quality of liver lesion [12 hemangiomas, 7 focal nodular hyperplasias (FNHs)] and liver vessel enhancement, and the global diagnostic quality of studies were ranked on a scale of 1-4 by two independent radiologists. Contrast-to-noise ratio (CNR) and % enhancement of liver vessels and lesions were calculated based on region of interest, signal intensity, and noise standard deviation measurements performed at 0, 20 s, 1, 3, and 5 min post-contrast injection. Qualitative and quantitative results were compared using the paired Wilcoxon signed rank and Student's t-tests, respectively. RESULTS: No qualitative differences were noted in enhancement of liver vessels, hemangiomas, and FNHs. There was no statistically significant difference between the global diagnostic qualities of scans performed with the two contrast agents. Quantitatively, liver vessels and hemangiomas did not demonstrate statistically significant differences in contrast enhancement. At 20 s, FNHs achieved higher CNR (P = 0.02) with gadodiamide. CONCLUSION: Half-dose gadobenate dimeglumine results in similar contrast enhancement compared to standard-dose gadodiamide in assessment of liver vessels, hemangiomas, and FNHs, and is a reasonable alternative to standard doses of extracellular agents in dynamic liver MRI.