Beth Ripley | University of Washington (original) (raw)

Papers by Beth Ripley

BENTHAM SCIENCE PUBLISHERS eBooks, Feb 1, 2016

Applied Radiology, Apr 1, 2016

Journal of The American College of Radiology, Nov 1, 2022

Peripheral arterial disease (PAD) affects millions across the world and in the United States betw... more Peripheral arterial disease (PAD) affects millions across the world and in the United States between 9% to 23% of all patients older than 55 years. The refinement of surgical techniques and evolution of endovascular approaches have improved the success rates of revascularization in patients afflicted by lower extremity PAD. However, restenosis or occlusion of previously treated vessels remains a pervasive issue in the postoperative setting. A variety of different imaging options are available to evaluate patients and are reviewed within the context of asymptomatic and symptomatic patients with PAD who have previously undergone endovascular or surgical revascularization. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

3D printing in medicine, Jun 24, 2022

Background: 3D printing (3DP) has enabled medical professionals to create patient-specific medica... more Background: 3D printing (3DP) has enabled medical professionals to create patient-specific medical devices to assist in surgical planning. Anatomical models can be generated from patient scans using a wide array of software, but there are limited studies on the geometric variance that is introduced during the digital conversion of images to models. The final accuracy of the 3D printed model is a function of manufacturing hardware quality control and the variability introduced during the multiple digital steps that convert patient scans to a printable format. This study provides a brief summary of common algorithms used for segmentation and refinement. Parameters for each that can introduce geometric variability are also identified. Several metrics for measuring variability between models and validating processes are explored and assessed. Methods: Using a clinical maxillofacial CT scan of a patient with a tumor of the mandible, four segmentation and refinement workflows were processed using four software packages. Differences in segmentation were calculated using several techniques including volumetric, surface, linear, global, and local measurements. Results: Visual inspection of print-ready models showed distinct differences in the thickness of the medial wall of the mandible adjacent to the tumor. Volumetric intersections and heatmaps provided useful local metrics of mismatch or variance between models made by different workflows. They also allowed calculations of aggregate percentage agreement and disagreement which provided a global benchmark metric. For the relevant regions of interest (ROIs), statistically significant differences were found in the volume and surface area comparisons for the final mandible and tumor models, as well as between measurements of the nerve central path. As with all clinical use cases, statistically significant results must be weighed against the clinical significance of any deviations found. Conclusions: Statistically significant geometric variations from differences in segmentation and refinement algorithms can be introduced into patient-specific models. No single metric was able to capture the true accuracy of the final models. However, a combination of global and local measurements provided an understanding of important geometric variations. The clinical implications of each geometric variation is different for each anatomical location and should be evaluated on a case-by-case basis by clinicians familiar with the process. Understanding the basic segmentation and refinement functions of software is essential for sites to create a baseline from which to evaluate their standard workflows, user training, and inter-user variability when using patient-specific models for clinical interventions or decisions.

RadioGraphics, 2021

The adoption of three-dimensional (3D) printing is rapidly spreading across hospitals, and the co... more The adoption of three-dimensional (3D) printing is rapidly spreading across hospitals, and the complexity of 3D-printed models and devices is growing. While exciting, the rapid growth and increasing complexity also put patients at increased risk for potential errors and decreased quality of the final product. More than ever, a strong quality management system (QMS) must be in place to identify potential errors, mitigate those errors, and continually enhance the quality of the product that is delivered to patients. The continuous repetition of the traditional processes of care, without insight into the positive or negative impact, is ultimately detrimental to the delivery of patient care. Repetitive tasks within a process can be measured, refined, and improved and translate into high levels of quality, and the same is true within the 3D printing process. The authors share their own experiences and growing pains in building a QMS into their 3D printing processes. They highlight errors encountered along the way, how they were addressed, and how they have strived to improve consistency, facilitate communication, and replicate successes. They also describe the vital intersection of health care providers, regulatory groups, and traditional manufacturers, who contribute essential elements to a common goal of providing quality and safety to patients. ©RSNA, 2021.

Journal of Cerebral Blood Flow and Metabolism, 2007

Journal of Vascular and Interventional Radiology, 2015

The informed consent conversation is a key component of patient-centered medicine, a concept that... more The informed consent conversation is a key component of patient-centered medicine, a concept that emphasizes the importance of patients actively participating in their care. Studies reveal that many informed consent conversations throughout medical practice lack essential elements and leave patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; needs unmet. This review addresses these deficiencies, discusses solutions, and introduces a standardized checklist that values the patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s role in shared decision making during the informed consent conversation. The checklist could be particularly helpful to interventional radiologists and other consulting physicians who usually obtain informed consent early in their encounters with patients.

Neurology, 2001

To examine the specificity of low CSF hypocretin-1 levels in narcolepsy and explore the potential... more To examine the specificity of low CSF hypocretin-1 levels in narcolepsy and explore the potential role of hypocretins in other neurologic disorders. Methods: A method to measure hypocretin-1 in 100 L of crude CSF sample was established and validated. CSF hypocretin-1 was measured in 42 narcolepsy patients (ages 16-70 years), 48 healthy controls (ages 22-77 years,) and 235 patients with various other neurologic conditions (ages 0-85 years). Results: As previously reported, CSF hypocretin-1 levels were undetectably low (Ͻ100 pg/mL) in 37 of 42 narcolepsy subjects. Hypocretin-1 levels were detectable in all controls (224-653 pg/mL) and all neurologic patients (117-720 pg/mL), with the exception of three patients with Guillain-Barré syndrome (GBS). Hypocretin-1 was within the control range in most neurologic patients tested, including patients with AD, PD, and MS. Low but detectable levels (100-194 pg/mL) were found in a subset of patients with acute lymphocytic leukemia, intracranial tumors, craniocerebral trauma, CNS infections, and GBS. Conclusions: Undetectable CSF hypocretin-1 levels are highly specific to narcolepsy and rare cases of GBS. Measuring hypocretin-1 levels in the CSF of patients suspected of narcolepsy is a useful diagnostic procedure. Low hypocretin levels are also observed in a large range of neurologic conditions, most strikingly in subjects with head trauma. These alterations may reflect focal lesions in the hypothalamus, destruction of the blood brain barrier, or transient or chronic hypofunction of the hypothalamus. Future research in this area is needed to establish functional significance.

Journal of the American College of Radiology : JACR, 2017

Breast cancer is the most common malignancy in women in the United States. Breast reconstruction ... more Breast cancer is the most common malignancy in women in the United States. Breast reconstruction surgery is a commonly used therapy for patients with breast cancer. The technique for the deep inferior epigastric perforator flap uses a preserved rectus muscle, which decreases donor site morbidity. Accurate identification and measurement of the perforator branches of the deep inferior epigastric artery is pivotal during pre-operative planning so that the surgeon can prioritize the best vessel to use and ultimately improve clinical outcome. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Developme...

RadioGraphics, 2022

As the medical applications of three-dimensional (3D) printing increase, so does the number of he... more As the medical applications of three-dimensional (3D) printing increase, so does the number of health care organizations in which adoption or expansion of 3D printing facilities is under consideration. With recent advancements in 3D printing technology, medical practitioners have embraced this powerful tool to help them to deliver high-quality patient care, with a focus on sustainability. The use of 3D printing in the hospital or clinic at the point of care (POC) has profound potential, but its adoption is not without unanticipated challenges and considerations. The authors provide the basic principles and considerations for building the infrastructure to support 3D printing inside the hospital. This process includes building a business case; determining the requirements for facilities, space, and staff; designing a digital workflow; and considering how electronic health records may have a role in the future. The authors also discuss the supported applications and benefits of medical 3D printing and briefly highlight quality and regulatory considerations. The information presented is meant to be a practical guide to assist radiology departments in exploring the possibilities of POC 3D printing and expanding it from a niche application to a fixture of clinical care. An invited commentary by Ballard is available online. ©RSNA, 2022.

Current Cardiology Reports, 2020

Medical Engineering & Physics

Medical Radiology, 2016

Muti-row-detector CT (MDCT) is the primary modality for evaluation of both congenital and acquire... more Muti-row-detector CT (MDCT) is the primary modality for evaluation of both congenital and acquired chest wall disorders. Imaging data from MDCT examinations provide anatomical detail and delineate relationships between adjacent structures. Three-dimensional reconstructions from the raw data can be used to enhance visualization of complex three-dimensional (3D) anatomy and for volumetric quantification to aid in surgical planning. This chapter illustrates the technical and practical considerations of utilizing MDCT in the evaluation of chest wall lesions, tumors, infections, and trauma and highlights MDCT advances in surgical planning, including 4D imaging and three-dimensional modeling and printing.

Journal of Vascular and Interventional Radiology, 2016

laboratory liver toxicities in a subset of patients. To date, no study has evaluated safety and e... more laboratory liver toxicities in a subset of patients. To date, no study has evaluated safety and efficacy of locoregional therapy (LRT) with radiofrequency ablation (RFA), transarterial chemoembolization (TACE) and radioembolization (TARE) during and after SBT. We present our early single center experience. Materials: Patients that underwent LRT with RFA, TACE and/or TARE after completing SBT or within 30 days of initiating SBT were retrospectively reviewed. Patient demographics and performance data were obtained from medical records. Toxicity was evaluated during sofosbuvir treatment and within 30 days of LRT using CTCAE criteria. Tumor response was evaluated using mRECIST criteria on all available follow-up CT/MRI. Results: Twenty-one patients (age 62 ± 6.3 y; ECOG 0:6, 1:14, 2:1; Child Pugh A:17, B:4) with HCC were treated between 2/ 2014 and 7/2015 with RFA (n¼5), TACE (n¼19) and TARE (n¼16) during or after sofosbuvir (n¼12) or ledipasvir-sofosbuvir (n¼9) therapy. Total SBT course was 12 weeks (n¼4) or 24 weeks (n¼16); 1 patient terminated SBT at 10 weeks due to persistent abdominal pain. AEs attributable to SBT included grade 1 (n¼1) and grade 2 (n¼1) hyperbilirubinemia, grade 2 thrombocytopenia (n¼1), grade 1 pancytopenia (n¼1) and grade 1 headache (n¼1). AEs within 30 days of LRT included grade 1 hypertransaminasemia (n¼1), grade 1 nausea (n¼2) and grade 1 abdominal pain (n¼2) after TACE and grade 1 fatigue (n¼1) after TARE. Objective response rate was 73% (CR:15, PR:4, SD:4, PD:3). Disease control rate was 88%. Conclusions: Locoregional therapy with RFA, TACE and TARE during or after sofosbuvir-based therapy for HCV is safe and effective. Treatment with SBT should not be delayed due to planned LRT for HCC. Continued study is required to evaluate long term efficacy and overall survival.

Frontiers in Bioengineering and Biotechnology, 2022

Critical-sized defects of irregular bones requiring bone grafting, such as in craniofacial recons... more Critical-sized defects of irregular bones requiring bone grafting, such as in craniofacial reconstruction, are particularly challenging to repair. With bone-grafting procedures growing in number annually, there is a reciprocal growing interest in bone graft substitutes to meet the demand. Autogenous osteo(myo)cutaneous grafts harvested from a secondary surgical site are the gold standard for reconstruction but are associated with donor-site morbidity and are in limited supply. We developed a bone graft strategy for irregular bone-involved reconstruction that is customizable to defect geometry and patient anatomy, is free of synthetic materials, is cellularized, and has an outer pre-vascularized tissue layer to enhance engraftment and promote osteogenesis. The graft, comprised of bioprinted human-derived demineralized bone matrix blended with native matrix proteins containing human mesenchymal stromal cells and encased in a simple tissue shell containing isolated, human adipose micro...

3D Printing and Additive Manufacturing

Three-dimensional (3D) printing technologies are increasingly used to convert medical imaging stu... more Three-dimensional (3D) printing technologies are increasingly used to convert medical imaging studies into tangible (physical) models of individual patient anatomy, allowing physicians, scientists, and patients an unprecedented level of interaction with medical data. To date, virtually all 3D-printable medical data sets are created using traditional image thresholding, subsequent isosurface extraction, and the generation of .stl surface mesh file formats. These existing methods, however, are highly prone to segmentation artifacts that either overor underexaggerate the features of interest, thus resulting in anatomically inaccurate 3D prints. In addition, they often omit finer detailed structures and require time-and labor-intensive processes to visually verify their accuracy. To circumvent these problems, we present a bitmap-based multimaterial 3D printing workflow for the rapid and highly accurate generation of physical models directly from volumetric data stacks. This workflow employs a thresholding-free approach that bypasses both isosurface creation and traditional mesh slicing algorithms, hence significantly improving speed and accuracy of model creation. In addition, using preprocessed binary bitmap slices as input to multimaterial 3D printers allows for the physical rendering of functional gradients native to volumetric data sets, such as stiffness and opacity, opening the door for the production of biomechanically accurate models.

3D Printing in Medicine

Background: Medical 3D printing has brought the manufacturing world closer to the patient's bedsi... more Background: Medical 3D printing has brought the manufacturing world closer to the patient's bedside than ever before. This requires hospitals and their personnel to update their quality assurance program to more appropriately accommodate the 3D printing fabrication process and the challenges that come along with it. Results: In this paper, we explored different methods for verifying the accuracy of a 3D printed anatomical model. Methods included physical measurements, digital photographic measurements, surface scanning, photogrammetry, and computed tomography (CT) scans. The details of each verification method, as well as their benefits and challenges, are discussed. Conclusion: There are multiple methods for model verification, each with benefits and drawbacks. The choice of which method to adopt into a quality assurance program is multifactorial and will depend on the type of 3D printed models being created, the training of personnel, and what resources are available within a 3D printed laboratory.