Publications by authors named "Ryan A Priest"

Background: Medium vessel occlusions (MeVOs) account for 25-40% of acute ischemic stroke. The Tenzing 5 (Route 92 Medical, San Mateo, California, USA) and FreeClimb 54 (Route 92 Medical, San Mateo, California, USA) catheter is a novel delivery-aspiration catheter combination designed to facilitate aspiration thrombectomy (AT) of MeVOs. We report our clinical experience using the Tenzing assisted delivery of aspiration (TADA) technique with FreeClimb 54 for first-line AT of MeVO.

View Article and Find Full Text PDF

Background: While endovascular thrombectomy (EVT) has become standard of care for patients' acute ischemic stroke (AIS) due to large vessel occlusion (LVO), many patients still suffer profound neurological disability, also termed futile recanalization (FR). The BAND score, which incorporates baseline disability, age, stroke severity, and treatment time window, is derived as a simple tool for upfront prediction of FR prior to EVT. This study aims to externally validate the BAND score and to incorporate upfront imaging biomarkers into the prediction tool.

View Article and Find Full Text PDF

Background: Treatment of large vessel occlusion (LVO) using mechanical thrombectomy with or without intravenous thrombolysis has demonstrated better outcomes compared to medical treatment alone. Large-bore aspiration catheters have been recently introduced. Their effectiveness and safety have not been demonstrated in a randomized trial.

View Article and Find Full Text PDF

Background: Increasing evidence supports the effectiveness of venous sinus stenting (VSS) with favorable outcomes, safety, and expenses compared with shunting for idiopathic intracranial hypertension. Yet, no evidence is available regarding optimal postoperative recovery, which has increasing importance with the burdens on health care imposed by the coronavirus disease 2019 pandemic. We examined adverse events and costs after VSS and propose an optimal recovery pathway to maximize patient safety and reduce stress on health care resources.

View Article and Find Full Text PDF

Background: Intra-arterial administration of chemotherapy with or without osmotic blood-brain barrier disruption enhances delivery of therapeutic agents to brain tumors. The aim of this study is to evaluate the safety of these procedures.

Methods: Retrospectively collected data from a prospective database of consecutive patients with primary and metastatic brain tumors who received intra-arterial chemotherapy without osmotic blood-brain barrier disruption (IA) or intra-arterial chemotherapy with osmotic blood-brain barrier disruption (IA/OBBBD) at Oregon Health and Science University (OHSU) between December 1997 and November 2018 is reported.

View Article and Find Full Text PDF

Prostate Dynamic-Contrast-Enhanced (DCE) MRI often exhibits fast and extensive global contrast reagent (CR) extravasation - measured by K(trans), a pharmacokinetic parameter proportional to its rate. This implies that the CR concentration [CR] is high in the extracellular, extravascular space (EES) during a large portion of the DCE-MRI study. Since CR is detected indirectly, through water proton signal change, the effects of equilibrium transcytolemmal water exchange may be significant in the data and thus should be admitted in DCE-MRI pharmacokinetic modeling.

View Article and Find Full Text PDF

The feasibility of shutter-speed model dynamic-contrast-enhanced MRI pharmacokinetic analyses for prostate cancer detection was investigated in a prebiopsy patient cohort. Differences of results from the fast-exchange-regime-allowed (FXR-a) shutter-speed model version and the fast-exchange-limit-constrained (FXL-c) standard model are demonstrated. Although the spatial information is more limited, postdynamic-contrast-enhanced MRI biopsy specimens were also examined.

View Article and Find Full Text PDF

Although neoadjuvant chemoradiation eradicates esophageal adenocarcinoma in a substantial proportion of patients, conventional imaging techniques cannot accurately detect this response. Dynamic contrast-enhanced magnetic resonance imaging is an emerging approach that may be well suited to fill this role. This pilot study evaluates the ability of this method to discriminate adenocarcinoma from normal esophageal tissue.

View Article and Find Full Text PDF