A Minimally-Interactive Watershed Algorithm Designed for Efficient CTA Bone Removal

Background: Percutaneous endoscopic lumbar discectomy (PELD) is one of the most sophisticated operative procedures for the treatment of lumbar disc herniation (LDH). Endoscopic techniques are now becoming standard in many areas due to expanded technical possibilities of full-endoscopic transforaminal or interlaminar resection of herniated lumbar discs as well as stenosis. However conventional percutaneous endoscopic interlaminar discectomy (PEID) disc operations may sometimes result in subsequent untoward complications due to unnoticed iatrogenic trauma to neural structures, which is mostly related to an anatomical limitation during endoscope insertion.Methods: An appropriate operative indication of the PEID without bone removal or laminectomy can be used to treat LDH cases with an enough interlaminar space (at least ≥ 20 mm by bi-facetal distance) from the reported evidences. Otherwise, there might be several indications for requirement of bone removal; a narrow interlaminar space, disappearance of the concave shape of the upper vertebral laminae, high-grade migration of LDH, recurrent LDH, obesity, or an immobile nerve root.Conclusion: The significance of PEID lies also in its minimal damage to surrounding structures such as muscle, bone, and ligaments. A discrete radiographic evaluation from the patient preoperatively is mandatory before choosing a proper endoscopic surgical modality for the sake of optimal clinical outcome after PEID.

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Aumento de coroa estética sem elevação de retalho – abordagem minimamente invasiva

Full Dentistry in Science ◽

10.24077/2020;1245-cj3439 ◽

2020 ◽

Vol 12 (45) ◽

pp. 34-39

Author(s):

Flavia Sukekava ◽

Julia Helena Luiz ◽

Paloma Palma ◽

Jaques Luiz

Keyword(s):

Minimally Invasive ◽

Correct Diagnosis ◽

Case Series ◽

Minimally Invasive Techniques ◽

Bone Removal ◽

Use Of Technology ◽

Treatment Plans ◽

Invasive Techniques ◽

Crown Lengthening ◽

Gummy Smile

Gummy smile is a characteristic in which the patient exposes more than 2 mm of keratinized gingiva in forced smile. With a multifactorial cause, its correct planning depends directly on the correct diagnosis. Usually, the procedures that involve manipulation and the enlargement of the aesthetical crown lengthening are surgical. The objective of this case series was to show the advantages of surgical crown augmentation surgery in aesthetic areas with minimally invasive techniques. Three cases of gummy smile were presented, with different treatment plans and techniques for execution. In the 3 cases, bone removal was performed with piezoelectric ultrasound, which made the postoperative more comfortable for patients. These cases illustrate the use of technology to reduce morbidity in patients who need to undergo bone removal to treat gingival smile.

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Segmentation In Medical Resonance images to extract the cancerous nodule for early diagnosis on cancer

INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY ◽

10.24297/ijct.v3i2a.2816 ◽

2012 ◽

Vol 3 (2) ◽

pp. 253-255

Author(s):

Raman Brar

Keyword(s):

Human Lung ◽

Research Work ◽

Vital Role ◽

Watershed Algorithm ◽

Segmentation Method ◽

Resonance Imaging ◽

Segmentation Methods ◽

Segmentation Accuracy ◽

Background Segmentation ◽

Lung Mri

Image segmentation plays a vital role in several medical imaging programs by assisting the delineation of physiological structures along with other parts. The objective of this research work is to segmentize human lung MRI (Medical resonance Imaging) images for early detection of cancer.Watershed Transform Technique is implemented as the Segmentation method in this work. Some comparative experiments using both directly applied watershed algorithm and after marking foreground and computed background segmentation methods show the improved lung segmentation accuracy in some image cases.

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Surgical Treatment of Diffuse Idiopathic Skeletal Hyperostosis (DISH) Involving the Cervical Spine: Technical Nuances and Outcome of a Multicenter Experience

Global Spine Journal ◽

10.1177/2192568220988272 ◽

2021 ◽

pp. 219256822098827

Author(s):

Giorgio Lofrese ◽

Alba Scerrati ◽

Massimo Balsano ◽

Roberto Bassani ◽

Michele Cappuccio ◽

...

Keyword(s):

Cervical Spine ◽

Clinical Outcome ◽

Waiting Times ◽

Diffuse Idiopathic Skeletal Hyperostosis ◽

Surgical Techniques ◽

Rare Condition ◽

Surgical Strategies ◽

Bone Removal ◽

Mild Dysphagia

Study Design: Retrospective multicenter. Objectives: diffuse idiopathic skeletal hyperostosis (DISH) involving the cervical spine is a rare condition determining disabling aero-digestive symptoms. We analyzed impact of preoperative settings and intraoperative techniques on outcome of patients undergoing surgery for DISH. Methods: Patients with DISH needing for anterior cervical osteophytectomy were collected. Swallow studies and endoscopy supported imaging in targeting bone decompression. Patients characteristics, clinico-radiological presentation, outcome and surgical strategies were recorded. Impact on clinical outcome of duration and time to surgery and different surgical techniques was evaluated through ANOVA. Results: 24 patients underwent surgery. No correlation was noted between specific spinal levels affected by DISH and severity of pre-operative dysphagia. A trend toward a full clinical improvement was noted preferring the chisel ( P = 0.12) to the burr ( P = 0.65), and whenever C2-C3 was decompressed, whether hyperostosis included that level ( P = 0.15). Use of curved chisel reduced the surgical times ( P = 0.02) and, together with the nasogastric tube, the risk of complications, while bone removal involving 3 levels or more ( P = 0.04) and shorter waiting times for surgery ( P < 0.001) positively influenced a complete swallowing recovery. Early decompressions were preferred, resulting in 66.6% of patients reporting disappearance of symptoms within 7 days. One and two recurrences respectively at clinical and radiological follow-up were registered 18-30 months after surgery. Conclusion: The “age of DISH” counts more than patients’ age with timeliness of decompression being crucial in determining clinical outcome even with a preoperative mild dysphagia. Targeted bone resections could be reasonable in elderly patients, while in younger ones more extended decompressions should be preferred.

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Posterior Midline Approach for a C2 Schwannoma: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opaa409 ◽

2020 ◽

Author(s):

Sorin Aldea ◽

Abdu Alkhairy ◽

Irina Joitescu ◽

Caroline Le Guerinel

Keyword(s):

Posterior Approach ◽

Main Step ◽

Surgical Removal ◽

Posterior Arch ◽

Favorable Result ◽

Lateral Compression ◽

Bone Removal ◽

Far Lateral ◽

Midline Approach ◽

Posterior Midline

Abstract C2 schwannomas are rare lesions that may develop in the spinal canal, in the area of the C2 ganglion situated posterior to the C1C2 articulation, in the extraspinal area or in a combination of these 3 sectors.1,2 The surgical removal of these lesions is delicate because of the intimate relationships the schwannomas develop with the V3 segment of the vertebral artery. A variety of lateral, far-lateral, or extreme lateral approaches have been described in order to tackle these lesions. We use a posterior midline approach that takes advantage of the predominantly extradural development of C2 schwannomas. In this technique, the main step is the debulking of the posterior articular sector of the tumor, which is easily accessible through a midline posterior approach and necessitates minimal bone removal. In most cases, removal of the homolateral posterior arch of C1 is sufficient in order to create an adequate access. These maneuvers create the necessary space for dissecting both the intradural and extraspinal sectors of the schwannoma. We present this technique through a case with a minimal intradural component exerting mainly a lateral compression of the spinal cord. The tumor was operated through the midline mini-invasive posterior approach with a favorable result. We demonstrate the surgical technique in video and discuss the nuances.

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A Novel Vegetation Point Cloud Density Tree-Segmentation Model for Overlapping Crowns Using UAV LiDAR

Remote Sensing ◽

10.3390/rs13081442 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1442

Author(s):

Kaisen Ma ◽

Yujiu Xiong ◽

Fugen Jiang ◽

Song Chen ◽

Hua Sun

Keyword(s):

Point Cloud ◽

Local Maximum ◽

Window Size ◽

Point Clouds ◽

High Density ◽

Watershed Algorithm ◽

Canopy Area ◽

Individual Trees ◽

Optimal Window ◽

Cloud Density

Detecting and segmenting individual trees in forest ecosystems with high-density and overlapping crowns often results in bias due to the limitations of the commonly used canopy height model (CHM). To address such limitations, this paper proposes a new method to segment individual trees and extract tree structural parameters. The method involves the following key steps: (1) unmanned aerial vehicle (UAV)-scanned, high-density laser point clouds were classified, and a vegetation point cloud density model (VPCDM) was established by analyzing the spatial density distribution of the classified vegetation point cloud in the plane projection; and (2) a local maximum algorithm with an optimal window size was used to detect tree seed points and to extract tree heights, and an improved watershed algorithm was used to extract the tree crowns. The proposed method was tested at three sites with different canopy coverage rates in a pine-dominated forest in northern China. The results showed that (1) the kappa coefficient between the proposed VPCDM and the commonly used CHM was 0.79, indicating that performance of the VPCDM is comparable to that of the CHM; (2) the local maximum algorithm with the optimal window size could be used to segment individual trees and obtain optimal single-tree segmentation accuracy and detection rate results; and (3) compared with the original watershed algorithm, the improved watershed algorithm significantly increased the accuracy of canopy area extraction. In conclusion, the proposed VPCDM may provide an innovative data segmentation model for light detection and ranging (LiDAR)-based high-density point clouds and enhance the accuracy of parameter extraction.

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