Using CycleGANs for effectively reducing image variability across OCT devices and improving retinal fluid segmentation

Optical coherence tomography (OCT) has become the most important imaging modality in ophthalmology. A substantial amount of research has recently been devoted to the development of machine learning (ML) models for the identification and quantification of pathological features in OCT images. Among the several sources of variability the ML models have to deal with, a major factor is the acquisition device, which can limit the ML model's generalizability. In this paper, we propose to reduce the image variability across different OCT devices (Spectralis and Cirrus) by using CycleGAN, an unsupervised unpaired image transformation algorithm. The usefulness of this approach is evaluated in the setting of retinal fluid segmentation, namely intraretinal cystoid fluid (IRC) and subretinal fluid (SRF). First, we train a segmentation model on images acquired with a source OCT device. Then we evaluate the model on (1) source, (2) target and (3) transformed versions of the target OCT images. The presented transformation strategy shows an F1 score of 0.4 (0.51) for IRC (SRF) segmentations. Compared with traditional transformation approaches, this means an F1 score gain of 0.2 (0.12).Comment: * Contributed equally (order was defined by flipping a coin) --------------- Accepted for publication in the "IEEE International Symposium on Biomedical Imaging (ISBI) 2019

High Variability of Acetabular Offset in Primary Hip Osteoarthritis Influences Acetabular Reaming—A Computed Tomography–Based Anatomic Study

Background: The objectives of the present study were to (1) evaluate the accuracy and reliability of native acetabular offset (AO) measurements performed on conventional supine anterior-posterior (ap) pelvis radiographs with reference to computed tomography (CT) in patients with end-stage hip osteoarthritis (OA); (2) determine the minimum and maximum amount of medialization of the center of rotation (COR) simulating different reaming techniques; and (3) identify patients at increased risk of excessive medialization of the COR.Methods: A consecutive series of corresponding 131 CT scans and radiographs of patients with primary hip OA was evaluated using validated software for three-dimensional acetabular and femoral measurements. We simulated the implantation of a hemispherical press-fit cup comparing anatomic and conventional reaming techniques and assessed corresponding changes in AO.Results: Standardized ap pelvis radiographs allowed for an accurate and reliable assessment of AO compared with CT. Cup placement in the most lateral position (anatomic reaming technique) resulted in a mean implant-related medialization of 5.9 ± 3.4 mm. Anatomic cup placement did not require reaming to the true floor in 64 hips (49%). With the conventional reaming technique, the total medialization of the COR (implant-related and reaming-related) was 6.8 ± 2.9, with 34% of cases having a medialization ≥8 mm.Conclusion: The present study highlights the variability of acetabular anatomy in patients with primary OA. AO can be accurately and reliably determined on conventional radiographs and appears to be independent of femoral shape and geometry. Depending on the preferred reaming technique a substantial number of patients appear at risk for excessive cup medialization

Curr Opin Ophthalmol

The application of artificial intelligence (AI) technologies in screening and diagnosing retinal diseases may play an important role in telemedicine and has potential to shape modern healthcare ecosystems, including within ophthalmology. In this article, we examine the latest publications relevant to AI in retinal disease and discuss the currently available algorithms. We summarize four key requirements underlining the successful application of AI algorithms in real-world practice: processing massive data; practicability of an AI model in ophthalmology; policy compliance and the regulatory environment; and balancing profit and cost when developing and maintaining AI models. The Vision Academy recognizes the advantages and disadvantages of AI-based technologies and gives insightful recommendations for future directions

Success and Shortfalls in Effort to Diversify N.F.L. Coaching

Todd Bowles had at least six interviews for N.F.L. head coaching jobs over the past five years. After each interview and rejection, he called an adviser to report who had been present, what questions had been asked, how long the interview had lasted and how he had performed

Success and Shortfalls in Effort to Diversify N.F.L. Coaching

Todd Bowles had at least six interviews for N.F.L. head coaching jobs over the past five years. After each interview and rejection, he called an adviser to report who had been present, what questions had been asked, how long the interview had lasted and how he had performed

Breaking convention: Essays on psychedelic consciousness

A multidimensional trip into psychedelic consciousness, science and culture, covering topics ranging from Neolithic worldviews, prehistoric rituals and Amerindian epistemology to weaponised hallucinogens, religious freedoms, trip-lit and the death of the '60s dream. This collection of 22 original essays transects a wide range of disciplines to offer empirical, mystical, imaginal, hermeneutic, queer, phenomenological and parapsychological perspectives on the exploration of psychedelics, taking in scientific debates on MDMA, manifestos and policy challenges

High Variability of Acetabular Offset in Primary Hip Osteoarthritis Influences Acetabular Reaming—A Computed Tomography–Based Anatomic Study

Background: The objectives of the present study were to (1) evaluate the accuracy and reliability of native acetabular offset (AO) measurements performed on conventional supine anterior-posterior (ap) pelvis radiographs with reference to computed tomography (CT) in patients with end-stage hip osteoarthritis (OA); (2) determine the minimum and maximum amount of medialization of the center of rotation (COR) simulating different reaming techniques; and (3) identify patients at increased risk of excessive medialization of the COR. Methods: A consecutive series of corresponding 131 CT scans and radiographs of patients with primary hip OA was evaluated using validated software for three-dimensional acetabular and femoral measurements. We simulated the implantation of a hemispherical press-fit cup comparing anatomic and conventional reaming techniques and assessed corresponding changes in AO. Results: Standardized ap pelvis radiographs allowed for an accurate and reliable assessment of AO compared with CT. Cup placement in the most lateral position (anatomic reaming technique) resulted in a mean implant-related medialization of 5.9 ± 3.4 mm. Anatomic cup placement did not require reaming to the true floor in 64 hips (49%). With the conventional reaming technique, the total medialization of the COR (implant-related and reaming-related) was 6.8 ± 2.9, with 34% of cases having a medialization ≥8 mm. Conclusion: The present study highlights the variability of acetabular anatomy in patients with primary OA. AO can be accurately and reliably determined on conventional radiographs and appears to be independent of femoral shape and geometry. Depending on the preferred reaming technique a substantial number of patients appear at risk for excessive cup medialization.</p