Topology-Aware Loss for Aorta and Great Vessel Segmentation in Computed Tomography Images

Segmentation networks are not explicitly imposed to learn global invariants of an image, such as the shape of an object and the geometry between multiple objects, when they are trained with a standard loss function. On the other hand, incorporating such invariants into network training may help improve performance for various segmentation tasks when they are the intrinsic characteristics of the objects to be segmented. One example is segmentation of aorta and great vessels in computed tomography (CT) images where vessels are found in a particular geometry in the body due to the human anatomy and they mostly seem as round objects on a 2D CT image. This paper addresses this issue by introducing a new topology-aware loss function that penalizes topology dissimilarities between the ground truth and prediction through persistent homology. Different from the previously suggested segmentation network designs, which apply the threshold filtration on a likelihood function of the prediction map and the Betti numbers of the ground truth, this paper proposes to apply the Vietoris-Rips filtration to obtain persistence diagrams of both ground truth and prediction maps and calculate the dissimilarity with the Wasserstein distance between the corresponding persistence diagrams. The use of this filtration has advantage of modeling shape and geometry at the same time, which may not happen when the threshold filtration is applied. Our experiments on 4327 CT images of 24 subjects reveal that the proposed topology-aware loss function leads to better results than its counterparts, indicating the effectiveness of this use

Current status of cadaver sources in Turkey and a wake-up call for Turkish anatomists

Persisting difficulties in body procurement in Turkey led to the acquisition of donated, unclaimed, autopsied, and imported bodies regulated under current legislature. Yet, no study had investigated the extent of the on-going cadaver problem. This study was aimed to outline cadaver sources in anatomy departments and their effectiveness by means of an online survey. Additionally, official websites of each department were investigated regarding any information on body donation. Unclaimed cadavers (84.8%) were the major source for anatomy departments, followed by donated (50%) and imported cadavers (39.1%). Foundation-based medical faculties were more likely to import cadavers (P=0.008). There was a moderate increase (r(s)=0.567; P=0.018) in donation registrations to our department after 2000. The departments in cities with significantly higher City-Based Gross Domestic Product measures (US$9,900 vs. US$16,772, P=0.041), frequencies for mid- or high-school graduates (30.4% vs. 31.3%, P=0.041), and frequencies for under- or post-graduates (13.1% vs. 15.8%, P=0.24) had managed to use donated cadavers. Anatomy departments' major reasons for using unclaimed cadavers were education (45.9%), unclaimed cadavers being the only source (24.3%), and receiving inadequate donations (21.6%). Nine out of seventy-four departments (12.2%) provided information regarding body donation on their websites. Body procurement remains as a serious problem in Turkey and it is apparent that current legislature does not provide a sufficient cadaver inflow. Similarly, anatomy departments' effectiveness in public awareness of body donation and support in the National Body Donation Campaign seems questionable. Anat Sci Educ 11: 155-165. (c) 2017 American Association of Anatomists

ANATOMY OF THE NUTRIENT FORAMEN ON THE HUMERUS, RADIUS AND ULNA: A REVIEW

Objective: The nutrient foramina are reported as a cause for union defects in humerus, radius and ulna fractures. We aimed to review the relationship between the anatomy of the nutrient foramina and fractures of these bones

The amount of information provided in articles published in clinical anatomy and surgical and radiologic anatomy regarding human cadaveric materials and trends in acknowledging donors/cadavers

Appreciating the contribution of donor-cadavers to medical education is a well observed practice among anatomists. However, the appreciation of their contribution in research and scientific articles remains dubious. We aimed to evaluate how much data anatomists provide about specimens they have used and how frequently anatomists acknowledge their cadavers in published articles

A mixed-type intermesenteric trunk as a major contributor to the ascending, transverse, and descending colons: a case report.

We present a case in which a mixed-type intermesenteric trunk was the major arterial supply for the ascending, transverse, and descending colons

Anatomical relations between anterior coracoscapular ligament and suprascapular neurovascular structures and a proposal for classification

Objective: Although suprascapular nerve entrapment is rare, the most common site of compression is the suprascapular notch. The anterior coracoscapular ligament (ACSL), which lies inferior to the superior transverse scapular ligament (STSL), may also be a cause of entrapment. We aimed to investigate the presence of ACSL and its relations to the suprascapular nerve and vessels

The Relationship of the Superficial Radial Nerve and Its Branch to the Thumb to the First Extensor Compartment

Purpose The superficial radial nerve and its branches are vulnerable during surgery for de Quervain tenovaginitis. We studied the proximity of the nerve branches to the first extensor compartment