Variability in Manual Segmentation of Temporal Bone Structures in Cone Beam CT Images.

PURPOSE: Manual segmentation of anatomical structures is the accepted "gold standard" for labeling structures in clinical images. However, the variability in manual segmentation of temporal bone structures in CBCT images of the temporal bone has not been systematically evaluated using multiple reviewers. Therefore, we evaluated the intravariability and intervariability of manual segmentation of inner ear structures in CBCT images of the temporal bone. METHODS: Preoperative CBCTs scans of the inner ear were obtained from 10 patients who had undergone cochlear implant surgery. The cochlea, facial nerve, chorda tympani, mid-modiolar (MM) axis, and round window (RW) were manually segmented by five reviewers in two separate sessions that were at least 1 month apart. Interreviewer and intrareviewer variabilities were assessed using the Dice coefficient (DICE), volume similarity, mean Hausdorff Distance metrics, and visual review. RESULTS: Manual segmentation of the cochlea was the most consistent within and across reviewers with a mean DICE of 0.91 (SD = 0.02) and 0.89 (SD = 0.01) respectively, followed by the facial nerve with a mean DICE of 0.83 (SD = 0.02) and 0.80 (SD = 0.03), respectively. The chorda tympani had the greatest amount of reviewer variability due to its thin size, and the location of the centroid of the RW and the MM axis were also quite variable between and within reviewers. CONCLUSIONS: We observed significant variability in manual segmentation of some of the temporal bone structures across reviewers. This variability needs to be considered when interpreting the results in studies using one manual reviewer.

A survey of preoperative diagnosis and management of complicated appendicitis.

INTRODUCTION: Complicated appendicitis is a severe condition, requiring early diagnosis and intervention to prevent complications. We aimed to investigate how resident surgeons distinguish and manage complicated appendicitis and their perspectives on preoperative diagnostic markers. METHODS: The electronic survey was face validated. It contained questions about demographics, resident surgeons' considerations on the preoperative diagnosis of complicated appendicitis, and views on the need for and relevance of preoperative diagnostic markers. It was sent to all resident surgeons in the Eastern part of Denmark. RESULTS: Seven hospitals and their 92 resident surgeons received the survey, and 90% responded. Most resident surgeons used symptoms and signs of pain to diagnose suspected complicated appendicitis. Half of the surgeons used computed tomographies, and 95% used routine blood tests. Most surgeons (83%) would change the management of patients with preoperatively diagnosed complicated appendicitis in comparison to uncomplicated appendicitis. However, only 17% felt the need for a preoperative diagnostic marker. CONCLUSIONS: Resident surgeons in Eastern Denmark use non-specific diagnostic techniques to distinguish complicated from uncomplicated appendicitis and would change treatment if appendicitis was diagnosed preoperatively. However, despite limited interest, our results suggest a need for new diagnostic markers to differentiate between the severity of appendicitis, thus enhancing education and training in managing such cases. FUNDING: None. TRIAL REGISTRATION: None.