scholarly journals Anatomic Landmarks and Morphometric Measurements for Accurate Localization of the Sphenopalatine Ganglion via the Transnasal and Infrazygomatic Approaches: A Cadaveric Study

2014 ◽  
Vol 48 (1) ◽  
pp. 14-18
Author(s):  
Daisy Sahni ◽  
Anjali Aggarwal ◽  
Tulika Gupta
Keyword(s):  
Intraoperative Imaging ◽  
Average Distance ◽  
Cadaveric Study ◽  
Anatomical Landmarks ◽  
Sphenopalatine Ganglion ◽  
Needle Placement ◽  
Anatomic Landmarks ◽  
Morphometric Measurements ◽  
Accurate Localization ◽  
Anterior Nasal Spine

ABSTRACT Objective Sphenopalatine ganglion (SPG) block is used for a variety of craniofacial pain syndromes either through the trans-nasal route or via the infrazygomatic approach. Intraoperative imaging can identify the pterygopalatine fossa (PPF) but not the exact position of the SPG. Accurate localization of the PG requires knowledge of the relevant anatomical landmarks. Materials and methods Thirty mid sagittal head and neck cadaveric sections were studied and the morphometric data was te correct SPG localization via trans-nasal roach and infrazygomatic approach. Results The sphenopalatine foramen (SPF) was located at an average distance of 55 mm from the anterior nasal spine at a mean angle of 22°. It was at or just superior to the midpoint of a line joining the skull base and the hard palate. The SPG was located 4 mm posterior and 4.7 mm lateral to the SPF at a mean distance of 6.3 mm from the SPF at an inclination of about 50° in both the sagittal and coronal planes. In the infrazygomatic approach, the SPG was between 4.5 and 6.3 cm the skin and an angle of about 7° posterior and inferior. Conclusion These morphometric measurements will be of help to the clinician for accurate electrode or needle placement for SPG block and in avoiding complications related to inaccurate needle placement. How to cite this article Gupta T, Aggarwal A, Sahni D. Anatomic Landmarks and Morphometric Measurements for Accurate Localization of the Sphenopalatine Ganglion via the Transnasal and Infrazygomatic Approaches: A Cadaveric Study. J Postgrad Med Edu Res 2014;48(1):14-18.

scholarly journals Landmarks For Accurate Sphenopalatine Ganglion Block Via the Transnasal and Infrazygomatic Approaches: A Cadaveric Study

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Tulika Gupta ◽  
Daisy Sahni
Keyword(s):  
Intraoperative Imaging ◽  
Average Distance ◽  
Anatomical Landmarks ◽  
Sphenopalatine Ganglion ◽  
Needle Placement ◽  
Ganglion Block ◽  
Sphenopalatine Foramen ◽  
Accurate Localization ◽  
Anterior Nasal Spine ◽  
Exact Position

Abstract INTRODUCTION Sphenopalatine ganglion (SPG) block is used for a variety of craniofacial pain syndromes either through the transnasal route or via the infrazygomatic approach. Intraoperative imaging can identify the pterygopalatine fossa (PPF) but not the exact position of the SPG. Accurate localization of the SPG requires knowledge of the relevant anatomical landmarks. METHODS A total of 30 mid sagittal head and neck cadaveric sections were studied. The specimens were fixed in anatomical position and the morphometric data was collected to facilitate correct SPG localization via trans-nasal approach and infrazygomatic approach. The metrical parameters were taken with the help of a digital vernier caliper accurate up to 0.02 mm. RESULTS The sphenopalatine foramen (SPF) was located at an average distance of 55 mm from the anterior nasal spine at a mean angle of 22°. It was at or just superior to the midpoint of a line joining the skull base and the hard palate. The SPG was located 4 mm posterior and 4.7 mm lateral to the SPF at a mean distance of 6.3 mm from the SPF at an inclination of about 50° in both the sagittal and coronal planes. In the infrazygomatic approach, the SPG was between 4.5 and 6.3 cm from the skin and at an angle of about 7° posterior and inferior. These two angles were remarkable in being almost same for all specimens in both the measured planes. CONCLUSION These morphometric measurements will be of help to the clinician for accurate electrode or needle placement for SPG block and in avoiding complications related to inaccurate needle placement.

Skull Localization using Ultrasound for Navigated Neurosurgery

2018 ◽  
Author(s):  
Grace Underwood
Keyword(s):  
Average Distance ◽  
Surface Registration ◽  
Optical Tracking ◽  
Line Of Sight ◽  
Clinical Test ◽  
Anatomical Landmarks ◽  
Accurate Localization ◽  
Skull Model ◽  
Tracked Ultrasound ◽  
Innovation And Technology

Image-guided navigation for neurosurgery requires accurate localization of the skull. Localization can be problematic when the patient is in a facedown position. The posterior skull lacks unique identifiable landmarks, which complicates standard localization methods using a tracked pointer. In addition to the lack of anatomical landmarks, trying to access facial surfaces is error-prone when working under the table and problems arise with line-of-sight of the optical tracker. We proposed the use of ultrasound to perform localization and investigated the accuracy of this process. A simulation study was performed to test the feasibility of ultrasound for localization on a plastic skull. An initial localization, using an optically tracked pointer, was performed to partially align pre-operative images and the skull model. Skull surface points were localized by optically tracked ultrasound and used in a surface registration algorithm. Accuracy and reproducibility was then investigated. Evaluation of the proposed localization method found that the average distance of points off the skull surface was 0.6 ± 0.1mm, which meets the same standards set by current commercially available systems for face-up positions. Using tracked ultrasound for registration is feasible for patients in facedown position. We provided a non-invasive method of registration that could be accomplished using one optical tracking camera, and maintains a constant line-of-sight. This project was performed in cooperation with Dr. Gernot Kronreif and the Austrian Center for Medical Innovation and Technology. Dr. Kronreif and his staff are preparing for a clinical test of this localization process.

scholarly journals A cadaveric study of the location and morphology of the central patellar ridge for bone-patellar tendon-bone graft

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Thanathep Tanpowpong ◽  
Thun Itthipanichpong ◽  
Thanasil Huanmanop ◽  
Nonn Jaruthien ◽  
Nattapat Tangchitcharoen
Keyword(s):  
Patellar Tendon ◽  
Cancellous Bone ◽  
Average Distance ◽  
Cadaveric Study ◽  
Anterior Cortex ◽  
Length Width ◽  
Central Ridge ◽  
The Mean ◽  
Bone Patellar Tendon ◽  
And Cartilage

Abstract Introduction The central ridge of the patella is the thickest area of patella and varies among patients. This cadaveric study identified the location and thickness of the bone at the central patella ridge for bone-patellar tendon-bone (BPTB) harvesting. Materials and methods Fifty cadaveric knees were assessed. First, the morphology, length, width, and location of the central patellar ridge were recorded. Then, we transversely cut the patella 25 mm from the lower pole and measured the thickness of the anterior cortex, cancellous bone, and cartilage from both the mid-patella and the central ridge location. Finally, the depth of the remaining cancellous bone at the mid-patella was compared to the bone at the central ridge. Results The location of the central-patellar ridge deviated medially from the mid-patella in 46 samples with an average distance of 4.36 ± 1 mm. Only 4 samples deviated laterally. The mean patella length was 41.19 ± 4.73 mm, and the width was 42.8 ± 5.25 mm. After a transverse cut, the remaining cancellous bone was significantly thicker at the central ridge compared to the bone at the mid-patella. Conclusions Most of the central patellar ridge deviated medially, approximately 4 mm from the mid-patella. Harvesting the graft from the central ridge would have more remaining bone compared to the mid-patella.

Fluorescein-Enhanced Characterization of Additional Anatomical Landmarks in Cerebral Ventricular Endoscopy

Neurosurgery ◽  
2013 ◽  
Vol 72 (5) ◽  
pp. 855-860 ◽  
Author(s):  
Pierluigi Longatti ◽  
Luca Basaldella ◽  
Francesco Sammartino ◽  
Alessandro Boaro ◽  
Alessandro Fiorindi
Keyword(s):  
Choroid Plexus ◽  
White Light ◽  
Area Postrema ◽  
Functional Anatomy ◽  
Circumventricular Organs ◽  
Third Ventriculostomy ◽  
Cancer Tissue ◽  
Anatomical Landmarks ◽  
Fluorescein Sodium ◽  
Anatomic Landmarks

Abstract BACKGROUND: Fluorescein enhancement to detect retinal disorder or differentiate cancer tissue in situ is a well-defined diagnostic procedure. It is a visible marker of where the blood-brain barrier is absent or disrupted. Little is reported in the contemporary literature on endoscopic fluorescein-enhanced visualization of the circumventricular organs, and the relevance of these structures as additional markers for safe ventricular endoscopic navigation remains an unexplored field. OBJECTIVE: To describe fluorescein sodium–enhanced visualization of circumventricular organs as additional anatomic landmarks during endoscopic ventricular surgery procedures. METHODS: We prospectively administered intravenously 500 mg fluorescein sodium in 12 consecutive endoscopic surgery patients. A flexible endoscope equipped with dual observation modes for both white light and fluorescence was used. During navigation from the lateral to the fourth ventricle, the endoscopic anatomic landmarks were first inspected under white light and then under the fluorescent mode. RESULTS: After a mean of 20 seconds in the fluorescent mode, the fluorescein enhanced visualization of the choroid plexus of the lateral ventricle, median eminence–tuber cinereum complex, organum vasculosum of the lamina terminalis, choroid plexus of the third and fourth ventricles, and area postrema. CONCLUSION: Fluorescein-enhanced visualization is a useful tool for helping neuroendoscopists recognize endoscopic anatomic landmarks. It could be adopted to guide orientation when the surgeon deems an endoscopic procedure unsafe or contraindicated because of unclear or subverted anatomic landmarks. Visualization of the circumventricular organs could add new insight into the functional anatomy of these structures, with possible implications for the site and safety of third ventriculostomy.

Zone 2 Flexor Hallucis Longus Tendoscopy: A Cadaveric Study

2009 ◽  
Vol 30 (5) ◽  
pp. 447-451 ◽  
Author(s):  
Tun Hing Lui ◽  
Kwok Bill Chan ◽  
Lap Ki Chan
Keyword(s):  
Tibial Nerve ◽  
Average Distance ◽  
Cadaveric Study ◽  
Flexor Hallucis Longus ◽  
Posterior Tibial Nerve ◽  
Medial Plantar Nerve ◽  
Endoscopic Findings ◽  
Posterior Tibial ◽  
Anatomic Dissection ◽  
The Relationship

Background: The purpose of this study was to verify the safety and efficacy of zone 2 flexor hallucis longus tendoscopy with the patient in the prone position. Materials and Methods: The technique was performed in 12 cadaver feet (6 pairs). The endoscopic findings were compared to an anatomic dissection. The locations of the posteromedial and plantar portals were studied. The relationship between the medial plantar nerve and the tract of FHL tendoscopy was also studied. Result: The average distance of the posteromedial portal above the medial malleolar tip was 10.3 mm. The average distance between the posteromedial portal and the posterior tibial nerve was 9.9 mm. The average distance between the plantar portal and the intermalleolar line was 41.5 mm. The average distance between the rod simulating the tenoscope and the nerve was 4.8 mm. The nerve was medial to the rod in 4 specimens and lateral to the rod in 8 specimens. Conclusion: Zone 2 flexor hallucis longus tendoscopy was a feasible approach to the deep portion of the flexor hallucis longus tendon in this cadaveric study. There is potential risk of damage to the medial plantar nerve. Clinical Relevance: These findings can help guide a surgeon who is considering trying this clinically.

scholarly journals Assessment of penetration of dorsal screws after fixation of the distal radius using ultrasound: cadaveric study

2016 ◽  
Vol 98 (2) ◽  
pp. 138-142 ◽  
Author(s):  
D Williams ◽  
J Singh ◽  
N Heidari ◽  
M Ahmad ◽  
A Noorani ◽  
...  
Keyword(s):  
Distal Radius ◽  
Intraoperative Imaging ◽  
Accurate Method ◽  
Cadaveric Study ◽  
Dorsal Cortex ◽  
Volar Plating ◽  
Specificity And Sensitivity ◽  
Soft Tissue Impingement ◽  
Screw Penetration ◽  
Aids Diagnosis

Introduction Volar locking plates are used to treat unstable and displaced fractures of the distal radius. Potential advantages of stable anatomical reduction (eg early mobilisation) can be limited by penetration of dorsal screws, leading to synovitis and potential rupture of extensor tendons. Despite intraoperative imaging, penetration of dorsal screws continues to be a problem in volar plating of the distal radius. Ultrasound is a well recognised, readily available, diagnostic tool used to assess soft-tissue impingement by orthopaedic hardware. In this cadaveric study, we wished to ascertain the sensitivity and specificity of ultrasound for identification of protrusion of dorsal screws after volar plating of the distal radius. Methods Four adult, unpaired phenol-embalmed cadaveric distal radii were used. A VariAx™ Distal Radius Volar Locking Plate system (Stryker, Kalamazoo, MI, USA) was employed for instrumented fixation. A portable SIUI CTS 900 ultrasound machine (Providian Medical, Eastlake, OH, USA) was used to image the dorsal cortex to ascertain screw penetration. Results Specificity and sensitivity of ultrasound for detection of screw protrusion through the dorsal cortex was 100%. Conclusions Ultrasound was found to be a safe and accurate method for assessment of dorsal-screw penetration through the dorsal cortex of the radius after volar plating of the distal radius. It also aids diagnosis of associated tendon disorders (eg tenosynovitis) that might cause pain and limit wrist function.

scholarly journals Real-Time Back Surface Landmark Determination Using a Time-of-Flight Camera

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6425
Author(s):  
Daniel Ledwoń ◽  
Marta Danch-Wierzchowska ◽  
Marcin Bugdol ◽  
Karol Bibrowicz ◽  
Tomasz Szurmik ◽  
...  
Keyword(s):  
Real Time ◽  
Average Distance ◽  
Time Of Flight ◽  
Point Clouds ◽  
Diagnostic Methods ◽  
Detection Methods ◽  
Back Surface ◽  
Anatomical Landmarks ◽  
Real Time Analysis ◽  
Similar Accuracy

Postural disorders, their prevention, and therapies are still growing modern problems. The currently used diagnostic methods are questionable due to the exposure to side effects (radiological methods) as well as being time-consuming and subjective (manual methods). Although the computer-aided diagnosis of posture disorders is well developed, there is still the need to improve existing solutions, search for new measurement methods, and create new algorithms for data processing. Based on point clouds from a Time-of-Flight camera, the presented method allows a non-contact, real-time detection of anatomical landmarks on the subject’s back and, thus, an objective determination of trunk surface metrics. Based on a comparison of the obtained results with the evaluation of three independent experts, the accuracy of the obtained results was confirmed. The average distance between the expert indications and method results for all landmarks was 27.73 mm. A direct comparison showed that the compared differences were statically significantly different; however, the effect was negligible. Compared with other automatic anatomical landmark detection methods, ours has a similar accuracy with the possibility of real-time analysis. The advantages of the presented method are non-invasiveness, non-contact, and the possibility of continuous observation, also during exercise. The proposed solution is another step in the general trend of objectivization in physiotherapeutic diagnostics.

Ultralow Dose Radiation 3D Intraoperative Imaging: How Low Can We Go? An O-Arm®, CT Scan, Cadaveric Study

2016 ◽  
Vol 16 (10) ◽  
pp. S133
Author(s):  
Vishal Sarwahi ◽  
Andrew Lee ◽  
Terry D. Amaral ◽  
Stephen Wendolowski ◽  
Rachel Gecelter ◽  
...  
Keyword(s):  
Ct Scan ◽  
Intraoperative Imaging ◽  
Cadaveric Study ◽  
Ultralow Dose ◽  
Dose Radiation

scholarly journals Prediction of the sphenopalatine ganglion localization in computerized tomography images

2019 ◽  
Vol 2 ◽  
pp. 251581631882469
Author(s):  
Joan Crespi ◽  
Daniel Bratbak ◽  
David Dodick ◽  
Manjit Matharu ◽  
Kent Are Jamtøy ◽  
...  
Keyword(s):  
Computerized Tomography ◽  
Average Distance ◽  
Ct Images ◽  
Ct Scans ◽  
Sphenopalatine Ganglion ◽  
Ct Guided ◽  
Bony Landmarks ◽  
Therapeutic Outcomes ◽  
Vidian Canal ◽  
Caucasian Patients

Background: The sphenopalatine ganglion (SPG) is a target for several headache syndromes. Most of the groups targeting the SPG do not localize it directly, and this might account for some therapeutic failures. As the SPG cannot be seen on computerized tomography (CT) scans, magnetic resonance image (MRI) must be used to visualize the ganglion. It would be advantageous to be able to predict the location of the SPG on CT scans for those using fluoroscopy or CT-guided injections and for those in whom MRI is not accessible or contraindicated. Methods: We localized the SPG in 21 Caucasian patients (21 right and 17 left ganglia; total 38) in 3 tesla MR images subsequently fused with CT scans. We measured the distance from the SPG to two bony landmarks identified on CT scans. We then applied the average distances to find an estimated position of the SPG. The first landmark was the center of the anterior opening of the vidian canal (VC). The second landmark was a point on the sphenoidal bone, defined in an axial plane at the level of the center of the VC (S-point). The predicted position of the SPG measured from the VC and the sphenoidal bone were referred to as, respectively, vcSPG and sSPG. Finally, the distances between the SPG, as seen on MRI, and predicted vcSPG/sSPG were calculated. Results: The average distance between SPG as seen on the MRI images and the estimated position based on CT images were 1.82 mm (SD 0.83, range 0.22–3.57 mm) for vcSPG and 2.09 mm (SD 0.99, range 0.71–4.79 mm) for sSPG. Conclusions: The localization of the SPG can be predicted on CT images using bony landmarks. Localization of the SPG may be important in achieving successful therapeutic outcomes for treatments that are directed toward the SPG.

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