Deep learning based medical image segmentation models usually require large datasets with high-quality dense segmentations to train, which are very time-consuming and expensive to prepare. One way to tackle this challenge is using the mixed-supervised learning framework, in which only a part of data is densely annotated with segmentation label and the rest is weakly labeled with bounding boxes. The model is trained jointly in a multi-task learning setting. In this paper, we propose Mixed-Supervised Dual-Network (MSDN), a novel architecture which consists of two separate networks for the detection and segmentation tasks respectively, and a series of connection modules between the layers of the two networks. These connection modules are used to transfer useful information from the auxiliary detection task to help the segmentation task. We propose to use a recent technique called Squeeze and Excitation in the connection module to boost the transfer. We conduct experiments on two medical image segmentation datasets. The proposed MSDN model outperforms multiple baselines.
BACKGROUND AND PURPOSE: MR imaging is not routinely used to image the extracranial facial nerve. The purpose of this study was to determine the extent to which this nerve can be visualized with a CISS sequence and to determine the feasibility of using that sequence for locating the nerve relative to tumor.
MATERIALS AND METHODS:Thirty-two facial nerves in 16 healthy subjects and 4 facial nerves in 4 subjects with parotid gland tumors were imaged with an axial CISS sequence protocol that included 0.8-mm isotropic voxels on a 3T MR imaging system with a 64-channel head/neck coil. Four observers independently segmented the 32 healthy subject nerves. Segmentations were compared by calculating average Hausdorff distance values and Dice similarity coefficients.
RESULTS:The primary bifurcation of the extracranial facial nerve into the superior temporofacial and inferior cervicofacial trunks was visible on all 128 segmentations. The mean of the average Hausdorff distances was 1.2 mm (range, 0.3-4.6 mm). Dice coefficients ranged from 0.40 to 0.82. The relative position of the facial nerve to the tumor could be inferred in all 4 tumor cases.
CONCLUSIONS:The facial nerve can be seen on CISS images from the stylomastoid foramen to the temporofacial and cervicofacial trunks, proximal to the parotid plexus. Use of a CISS protocol is feasible in the clinical setting to determine the location of the facial nerve relative to tumor.
Objective
To evaluate the historical descriptive origins of the extracranial transnasal transsphenoidal route to the sphenoid sinus and sella turcica focusing on the works of two otolaryngologists: Markus Hajek (1861–1941) and Oskar Hirsch (1877–1965).
Data Sources
A collection of primary references of author publications, and contemporary references and textbooks.
Review Methods
Primary references were reviewed with specific focus on surgical routes to the sphenoid sinus and sella turcica. Chronology was cross‐referenced with contemporary publications by contemporaries. Translations from German were conducted by author AM when necessary.
Results
Markus Hajek elegantly described the surgical approach to the posterior ethmoids and sphenoid sinus in 1904 using a transnasal route. Building on this foundation, Oskar Hirsch described the fully extracranial endonasal transethmoid transsphenoidal approach in 1909. He was first to describe surgical entrance to the sella using this exclusively unilateral endonasal route, which he demonstrated on a cadaver. He reports performing this procedure on a live patient in April, 1910, under local anesthesia in stages over 5 weeks. For better exposure, Hirsch consolidated his method with Killian's submucosal window resection of the posterior nasal septum allowing for bilateral access to the sphenoid sinus and sella, and completed a single stage procedure on a patient in June 1910.
Conclusion
Oskar Hirsch was the first to describe and perform a stepwise surgical approach to the sella using an exclusively extracranial, endonasal, transethmoid, and transsphenoidal approach. He built upon his mentor Markus Hajek's approaches to the posterior ethmoid cells and sphenoid sinus.
Level of Evidence
NA: Background information, synthesis from multiple sources emphasizing factual information Laryngoscope, 133:807–813, 2023
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.