Anatomical landmarks for localizing the otic ganglion: A possible new treatment target for headache disorders

Background: The otic ganglion (OG) is a cranial parasympathetic ganglion located in the infratemporal fossa under the foramen ovale (FO) and adjacent to the medial part of the mandibular nerve. Parasympathetic innervation of intracranial vessels from the OG has been shown both in animal and human models and evidence suggests that the OG plays an important role in the cranial vasomotor response. We review the evidence that positions the OG as a viable target for headache disorders. The OG is a small structure and not detectable on medical imaging. The FO is easily identifiable on CT scans and the mandibular nerve on MRI, hence, the position of the OG may be predicted if the mean distance from the FO is known. Objective: The objective is to describe the average distance between the FO and the OG in a sample of 18 infratemporal fossae from 21 cadavers. Methods: A total of 21 high definition photographs of 21 infratemporal fossae from 18 cadavers were analyzed. The distance between the inferior edge of the medial part of the FO to the OG was measured. Results: Four photographs of infratemporal fossae of four cadavers were excluded due to the inability to localize the inferior edge of the FO. A total of 15 infratemporal fossae from 17 cadavers were measured. The mean distance from the FO to the OG was 4.5 mm (SD 1.7), range 2.1–7.7 mm. Conclusions: We have described the average distance from the OG to an easily identifiable anatomical landmark that is visible in CT scans, the FO. This anatomical study may aid in the development of strategies to localize the OG in order to explore its role as a therapeutic target for headache disorders.

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A radiographic computed tomography–based study to determine the ideal entry point, trajectory, and length for safe fixation using C-2 pars interarticularis screws

Journal of Neurosurgery Spine ◽

10.3171/2009.12.spine09543 ◽

2010 ◽

Vol 12 (6) ◽

pp. 602-612 ◽

Cited By ~ 11

Author(s):

Daniel J. Hoh ◽

Charles Y. Liu ◽

Michael Y. Wang

Keyword(s):

Entry Point ◽

Ct Scans ◽

Lateral Mass ◽

Transverse Foramen ◽

Inferior Aspect ◽

Significant Difference ◽

Pars Interarticularis ◽

Entry Points ◽

The Mean ◽

Inferior Edge

Object Effective methods for fixation of the axis include C1–2 transarticular and C-2 pedicle screw placement. Both techniques pose a risk of vertebral artery (VA) injury in patients with narrow pedicles or an enlarged, high-riding VA. Pars screws at C-2 avoid the pedicle, but can cause VA injury with excessively long screws. Therefore, the authors evaluated various entry points and trajectories to determine ideal pars screw lengths that avoid breaching the transverse foramen. Methods Both pars were studied on 50 CT scans (100 total). Various pars lengths were assessed using 2 entry points and 3 trajectories (6 measurements). Entry point A was the superior one-fourth of the lateral mass. Entry point B was 3-mm rostral to the inferior aspect of the lateral mass. Using entry points A and B, Trajectory 1 was the minimum distance to the transverse foramen; Trajectory 2 was the maximum distance to the transverse foramen; and Trajectory 3 was the steepest angle to the pars/C-2 superior facet junction without transverse foramen breach. Results The mean patient age was 46 ± 17 years, and 84% of the CT scans reviewed were obtained in men. There was no significant difference in right or left measurements. Entry point B demonstrated greater pars lengths for each trajectory compared with entry point A (p < 0.0001). For both entry points, Trajectory 3 provided the greatest pars length. Using Trajectory 3 with entry point B, 84, 95, and 99% had a pars length that measured ≥ 18, 16, and 14 mm, respectively. Using Trajectory 3 with Entry point A, only 41, 64, and 87% had a pars length that measured ≥ 18, 16, and 14 mm, respectively. Conclusions Using an entry point 3-mm rostral to the inferior edge of the lateral mass and a trajectory directed toward the superior facet/pars junction, 99% of partes interarticularis in this study would tolerate a 14-mm screw without breach of the transverse foramen.

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The use of an O-arm in endonasal endoscopic operations of the skull base

BMC Surgery ◽

10.1186/s12893-021-01066-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Vlastimil Novák ◽

Lumír Hrabálek ◽

Jan Valošek ◽

Jakub Jablonský ◽

Jiří Hoza ◽

...

Keyword(s):

Skull Base ◽

Ct Scans ◽

Anatomical Landmarks ◽

Endoscopic Endonasal ◽

X Ray ◽

Mean Error ◽

Neuronavigation System ◽

Hypophyseal Adenoma ◽

The Mean ◽

Ct And Mri

Abstract Background Endoscopic endonasal transsphenoidal approaches are broadly used nowadays for a vast spectrum of pathologies sited in the anterior and middle cranial fossa. The usage of neuronavigation systems (neuronavigation) in these surgeries is crucial for improving orientations deeply inside the skull and increasing patient safety. Methods The aim of this study was to assess the use of optical neuronavigation, together with an intraoperative O-arm O2 imaging system, in a group of patients with hypophyseal adenoma that underwent a transnasal transsphenoidal surgery, and correlate the accuracy and its deviation during the navigational process against the use of conventional neuronavigation that uses preoperative MRI and CT scans. The overall group consisted of six patients, between 39 and 78 years old, with a diagnosis of hypophyseal adenoma. Patients were treated with an endoscopic transsphenoidal technique and all of them underwent preoperative MRI and CT scans of the brain. These images were used in the neuronavigation system StealthStation S7® during the surgery, where we defined two bony anatomical landmarks, such as a vomer or the origin of an intrasphenoidal septum, in each operated patient. The tip of the navigational instrument, under endoscopic control, pointed to these landmarks and the distance between the tip and the bony structure was measured on the neuronavigation system. Afterwards, intraoperative 3D x-ray imaging was performed via the mobile system O-arm O2® system with automatic transfer into the navigational system. Under endoscopic guidance, we localized the identical bony anatomical landmarks used in the previous measurement and re-measured the distance between the tip and bony landmark in images acquired by the O-arm. The results of both measurements were statistically compared. Results The mean error of accuracy during conventional neuronavigation with usage of preoperative CT and MRI scans was 2.65 mm. During the neuronavigation, with utilization of intraoperative 3D O-arm images, the mean error of accuracy 0 mm. These mean errors of accuracy (both measurement methods were compared by nonparametric Wilcoxon test) had a statistically significant difference (p = 0.043). Conclusions Based on this preliminary clinical study, we conclude that the O-arm is capable of providing intraoperative x-ray 3D images in sufficient spatial resolution in a clinically feasible acquisition. The mean error of accuracy during intraoperative navigation, based on 3D O-arm scans at the skull base, is significantly lower compared to the usage of navigation using conventional presurgical CT and MRI images. This suggests the suitability of this method for utilization during endoscopic endonasal skull base approaches.

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Relative position of the supra-acetabular bone to the crestal plane: a radiological analysis

Journal of the Royal Army Medical Corps ◽

10.1136/jramc-2019-001251 ◽

2019 ◽

pp. jramc-2019-001251

Author(s):

George Dehn ◽

N Hammer ◽

M C Wyatt ◽

S J Soltani ◽

D C Kieser

Keyword(s):

Relative Position ◽

Trauma Centre ◽

Ct Scans ◽

Anatomical Landmarks ◽

Rapid Reduction ◽

Acetabular Bone ◽

Pelvic Injuries ◽

Life Threatening ◽

The Mean ◽

Austere Environments

IntroductionDisplaced unstable pelvic injuries are life threatening and require rapid reduction and stabilisation, typically achieved with an external fixator. Recently, the benefits of supra-acetabular pins have been proven; however, these are usually inserted under fluoroscopic guidance. In austere environments and in extremis, this facility is limited and fixation using anatomical landmarks is required. Thus, the aim of this study is to determine the relative position of the supra-acetabular bone to the crestal plane and examine its consistency in military-aged European personnel.MethodsA radiological review of 50 randomised pelvic CT scans in European patients aged 18–30 years from a Level 1 trauma centre was performed. The CT scans were analysed using 3D rendering software. The relative position of the supra-acetabular bone to the crestal plane was determined.ResultsThe supra-acetabular bone relative to the crestal plane was approximately 28° caudal and 24° medial to the crestal plane. The mean minimum distance from the pin’s entry point to the sciatic notch was approximately 73 mm. There were no differences noted between genders or hemipelvic side.ConclusionsThe supra-acetabular bone maintains a consistent relative position to the crestal plane. Thus, with the surgeon’s thumb on the anterior superior iliac spine (ASIS) and index finger on the iliac tubercle, defining the crestal plane, a supra-acetabular pin can be inserted into the anterior inferior iliac spine, which lies 3 cm inferior and 2 cm medial to the ASIS, and advanced along the supra-acetabular bone by angling the pin 30° caudal and 25° medial to the crestal plane.

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Accuracy of the freehand pass technique for ventriculostomy catheter placement: retrospective assessment using computed tomography scans

Journal of Neurosurgery ◽

10.3171/jns/2008/108/01/0088 ◽

2008 ◽

Vol 108 (1) ◽

pp. 88-91 ◽

Cited By ~ 107

Author(s):

David R. Huyette ◽

Benjamin J. Turnbow ◽

Christian Kaufman ◽

Dale F. Vaslow ◽

Benjamin B. Whiting ◽

...

Keyword(s):

Computed Tomography ◽

Lateral Ventricle ◽

Third Ventricle ◽

Catheter Placement ◽

Ct Scans ◽

Anatomical Landmarks ◽

Retrospective Assessment ◽

Catheter Tip ◽

Interhemispheric Fissure ◽

The Mean

Object The standard method of ventriculostomy catheter placement is a freehand pass technique using surface anatomical landmarks. This study was undertaken to determine the accuracy of successful ventriculostomy procedures performed at a single institution's intensive care unit (ICU). The authors hypothesized that use of surface anatomical landmarks alone with successful results frequently do not correlate with desirable catheter tip placement. Methods Retrospective evaluation was performed on the head computed tomography (CT) scans of 97 patients who underwent 98 freehand pass ventriculostomy catheter placements in an ICU setting. Using the postprocedure CT scans of the patients, 3D measurements were made to calculate the accuracy of ventriculostomy catheter placement. Results The mean distance (± standard deviation [SD]) from the catheter tip to the Monro foramen was 16 ± 9.6 mm. The mean distance (± SD) from the catheter tip to the center of the bur hole was 87.4 ± 14.0 mm. Regarding accurate catheter tip placement, 56.1% of the catheter tips were in the ipsilateral lateral ventricle, 7.1% were in the contralateral lateral ventricle, 8.2% were in the third ventricle, 6.1% were within the interhemispheric fissure, and 22.4% were within extraventricular spaces. Conclusions The accuracy of freehand ventriculostomy catheterization at the authors' institution typically required 2 passes per successful placement, and, when successful, was 1.6 cm from the Monro foramen. More importantly, 22.4% of these catheter tips were in nonventricular spaces. Although many neurosurgeons believe that the current practice of ventriculostomy is good enough, the results of this study show that there is certainly much room for improvement.

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Metacarpal Bony Dimensions Related to Headless Compression Screw Sizes

Journal of Hand and Microsurgery ◽

10.1055/s-0039-3400443 ◽

2019 ◽

Vol 12 (S 01) ◽

pp. S39-S44

Author(s):

Michael Okoli ◽

Kevin Lutsky ◽

Michael Rivlin ◽

Brian Katt ◽

Pedro Beredjiklian

Keyword(s):

Computed Tomography ◽

Fracture Fixation ◽

Ct Scans ◽

Compression Screw ◽

Metacarpal Head ◽

Headless Compression Screw ◽

Metacarpal Bones ◽

Headless Compression Screws ◽

The Mean ◽

Distal Aspect

Abstract Introduction The purpose of this study is to determine the radiographic dimensions of the finger metacarpals and to compare these measurements with headless compression screws commonly used for fracture fixation. Materials and Methods We analyzed computed tomography (CT) scans of the index, long, ring, and small metacarpal bones and measured the metacarpal length, distance from the isthmus to the metacarpal head, and intramedullary diameter of the isthmus. Metacarpals with previous fractures or hardware were excluded. We compared these dimensions with the size of several commercially available headless screws used for intramedullary fixation. Results A total of 223 metacarpals from 57 patients were analyzed. The index metacarpal was the longest, averaging 67.6 mm in length. The mean distance from the most distal aspect of the metacarpal head to the isthmus was 40.3, 39.5, 34.4, and 31 mm for the index, long, ring, and small metacarpals, respectively. The narrowest diameter of the isthmus was a mean of 2.6, 2.7, 2.3, and 3 mm for the index, long, ring, and small metacarpals, respectively. Of 33 commercially available screws, only 27% percent reached the isthmus of the index metacarpal followed by 42, 48, and 58% in the long, ring, and small metacarpals, respectively. Conclusion The index and long metacarpals are at a particular risk of screw mismatch given their relatively long lengths and narrow isthmus diameters.

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The role of exudation in chronic subdural hematomas

Journal of Neurosurgery ◽

10.3171/jns-07/08/0290 ◽

2007 ◽

Vol 107 (2) ◽

pp. 290-295 ◽

Cited By ~ 31

Author(s):

Mehmet Tokmak ◽

A. Celal Iplikcioglu ◽

Sirzat Bek ◽

Cem Atilla Gökduman ◽

Mustafa Erdal

Keyword(s):

Outer Membrane ◽

Clinical Status ◽

Ct Scans ◽

Subdural Hematomas ◽

The Mean ◽

Grade 3 ◽

Age Range ◽

Exudation Rate

Object Chronic subdural hematomas (SDHs) are a local inflammatory process that causes the formation of a granulation tissue often referred to as the external or outer membrane. This membrane has abnormally permeable macrocapillaries. Therefore, exudation from the macrocapillaries in the outer membrane of chronic SDH may play an important role in the enlargement of chronic SDH. In this study the authors investigated the role of exudation in chronic SDH. Methods The authors examined 24 patients (16 men and eight women; age range 38–86 years [mean age 61.4 years]) with 27 chronic SDHs. The clinical status of the patients was evaluated according to the classification described by Markwalder. The diagnosis was established on computed tomography (CT) scans in all cases. The authors also used the Nomura Classification for judging the lesion's appearance on CT scans. Immediately after the diagnosis, all patients were administered 20 mCi (740 mBq) technetium-99m human serum albumin. Four hours later, blood and SDH samples were taken and radioactivity levels were measured in each. The ratio of activity of the samples taken from chronic SDH to the radioactivity of blood was determined as a percentage and defined as the exudation rate. On the follow-up CT scan obtained on postoperative Day 20, subdural collections thicker than 5 mm were determined to be a reaccumulation. Results The correlations between the exudation rate and age of the patients, clinical grades, CT appearances, and amount of reaccumulation were investigated. In this series the average exudation rate was 13.24% (range 2.05–28.88%). The mean exudation rates according to the clinical grades assigned to patients were as follows: Grade 0, 8.67 ± 5.64% (three patients); Grade 1, 5.07 ± 1.43% (eight patients); Grade 2, 17.87 ± 3.73% (seven patients); and Grade 3, 19.65 ± 7.67% (six patients). Exudation rates in patients with Grades 2 and 3 were significantly higher than those in Grades 0 and 1 (p < 0.05). The mean exudation rates according to the lesion's appearance on CT scans were found as follows: hypodense appearance, 6.55 ± 4.52% (eight patients); isodense appearance, 11.07 ± 6.32% (five patients); hyperdense appearance, 19.47 ± 13.61% (three patients); and mixed-density appearance, 17.40 ± 5.80% (nine patients). The differences among the groups were significant (p < 0.05). The average exudation rate was statistically higher in the patients with reaccumulation (16.30 ± 8.16%) than that in the patients without reaccumulation (9.96 ± 6.84%) (p < 0.05). Conclusions The exudation rate in chronic SDH is correlated with a higher clinical grade (Markwalder Grade 2 or 3), mixed-density CT appearance, and reaccumulation. Therefore, exudation from macrocapillaries in the outer membrane of chronic SDH probably plays an important role in the pathophysiology and the growth of chronic SDH.

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3D Volumetric Analysis and Anatomical Considerations for Sinus Bone Graft

Applied Sciences ◽

10.3390/app11030951 ◽

2021 ◽

Vol 11 (3) ◽

pp. 951

Author(s):

Ji Hyoung Kim ◽

Hyo Joon Kim ◽

Ye Joon Jo ◽

Jun Seok Choi ◽

Seong Yong Moon

Keyword(s):

Bone Graft ◽

Maxillary Sinus ◽

Alveolar Bone ◽

Lateral Wall ◽

Volumetric Analysis ◽

Ct Scans ◽

Sinus Floor Elevation ◽

Sinus Wall ◽

Sinus Floor ◽

The Mean

The aim of this study is to evaluate anatomical considerations and assess the volume of the maxillary sinus bone graft. There were sixty-three patients (eighty-three sinuses) who had taken CT scans for implant surgery. Patients included those whose height of the residual alveolar bone was less than 5 mm. The position of posterior superior alveolar artery, the thickness of the maxillary sinus wall, and the volume of the maxillary sinus according to the amount of sinus floor elevation were measured. The mean vertical distance of posterior superior alveolar artery was 11.91 ± 4.79 mm from 3.03 mm to 24.05 mm. The mean thickness of the lateral wall was 1.71 ± 0.55 mm in the range of 0.74 mm to 3.93 mm. The volume of 3 mm, 5 mm, 7 mm, and 10 mm from the sinus floor was 0.173 ± 0.11 cm3, 0.526 ± 0.25 cm3, 1.068 ± 0.43 cm3, and 2.184 ± 0.74 cm3 on average, respectively. The knowledge of the posterior superior alveolar artery position, the lateral wall thickness, and the volume of the maxillary sinus can help the clinician for sinus bone graft.

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

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02244-5 ◽

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.

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Comparison of standardized uptake values measured on 18F-NaF PET/CT scans using three different tube current intensities

Radiologia Brasileira ◽

10.1590/0100-3984.2014.0034 ◽

2015 ◽

Vol 48 (1) ◽

pp. 17-20 ◽

Cited By ~ 1

Author(s):

Agnes Araujo Valadares ◽

Paulo Schiavom Duarte ◽

Eduardo Bechtloff Woellner ◽

George Barberio Coura-Filho ◽

Marcelo Tatit Sapienza ◽

...

Keyword(s):

Attenuation Correction ◽

Lumbar Vertebra ◽

Ct Scans ◽

Femoral Diaphysis ◽

Standardized Uptake Values ◽

Pet Ct ◽

Tube Current ◽

The Mean ◽

Humeral Diaphysis ◽

Ct Studies

Objective: To analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on 18FNaF PET/CT scans. Materials and Methods: A total of 254 18F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Results: Mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: The three tube current values yielded similar results for SUV calculation.

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A Geometric Model of the Beating Heart

Methods of Information in Medicine ◽

10.1160/me9044 ◽

2007 ◽

Vol 46 (03) ◽

pp. 282-286 ◽

Cited By ~ 5

Author(s):

C. Lorenz ◽

J. von Berg

Keyword(s):

Computed Tomography ◽

A Priori ◽

Anatomical Landmarks ◽

Motion Model ◽

A Priori Information ◽

Average Accuracy ◽

Tomography Image ◽

The Mean ◽

Priori Information ◽

Computed Tomography Image

Summary Objectives : A comprehensive model of the human heart that covers multiple surfaces, like those of the four chambers and the attached vessels, is presented. It also contains the coronary arteries and a set of 25 anatomical landmarks. The statistical model is intended to provide a priori information for automated diagnostic and interventional procedures. Methods : The end-diastolic phase of the model was adapted to fit 27 clinical multi-slice computed tomography images, thus reflecting the anatomical variability to be observed in that sample. A mean cardiac motion model was also calculated from a set of eleven multi-phase computed tomography image sets. A number of experiments were performed to determine the accuracy of model-based predictions done on unseen cardiac images. Results : Using an additional deformable surface technique, the model allows for determination of all chambers and the attached vessels on the basis of given anatomical landmarks with an average accuracy of 1.1 mm. After such an individualization of the model by surface adaptation the centerlines of the three main coronary arteries may be estimated with an average accuracy of 5.2 mm. The mean motion model was used to estimate the cardiac phase of an unknown multislice computed tomography image. Conclusion : The mean shape model of the human heart as presented here complements automated image analysis methods with the required a priori information about anatomical constraints to make them work fast and robustly.

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