Search

Background Sacral neuromodulation (SNM) is an established treatment option for patients with faecal incontinence. The location of the stimulating electrode is considered to be essential for treatment success. The purpose of this study was to evaluate the position of SNM electrodes after using a standardized fluoroscopy-guided implantation technique. Methods For this cadaver study, SNM electrodes were implanted bilaterally in 5 lower body specimens. The lower edge of the sacroiliac joint and the medial edge of the sacral foramina were marked using fluoroscopy to draw an ‘H’ with the crossing points identifying S3. After electrode placement the pelvis was dissected to describe the exact position of the SNM electrodes. Results The electrodes were inserted at an angle with a median degree measure of 60° (range 50–65°) to the skin, with a median distance of 9 mm (range 0–13 mm) from the S3 marking. All electrodes entered the third sacral foramen. The median distance of the electrodes to the sacral nerve was 0 mm (range 0–3 mm) for the most proximal, 0.5 mm (range 0–5 mm) for the second, 2.25 mm (range 0–11 mm) for the third and 1.75 mm (range 0–16 mm) for the most distant electrode. There was neither a significant difference in the proximity of the electrodes to the nerve between the right and left side (proximal to distal electrode: p = 0.18, p = 0.16, p = 0.07, p = 0.07) nor between male and female cadavers (p = 0.25, p = 0.21, p = 0.66, p = 0.66). Conclusions A standardized fluoroscopy-guided implantation technique enables a close contact between electrode and nerve. This can potentially result in an improved clinical outcome.

Background: Spina bifida aperta (SBA) is a birth defect associated with severe anatomical changes in the developing fetal brain. Brain magnetic resonance imaging (MRI) atlases are popular tools for studying neuropathology in the brain anatomy, but previous fetal brain MRI atlases have focused on the normal fetal brain. We aimed to develop a spatio-temporal fetal brain MRI atlas for SBA. Methods: We developed a semi-automatic computational method to compute the first spatio-temporal fetal brain MRI atlas for SBA. We used 90 MRIs of fetuses with SBA with gestational ages ranging from 21 to 35 weeks. Isotropic and motion-free 3D reconstructed MRIs were obtained for all the examinations. We propose a protocol for the annotation of anatomical landmarks in brain 3D MRI of fetuses with SBA with the aim of making spatial alignment of abnormal fetal brain MRIs more robust. In addition, we propose a weighted generalized Procrustes method based on the anatomical landmarks for the initialization of the atlas. The proposed weighted generalized Procrustes can handle temporal regularization and missing annotations. After initialization, the atlas is refined iteratively using non-linear image registration based on the image intensity and the anatomical land-marks. A semi-automatic method is used to obtain a parcellation of our fetal brain atlas into eight tissue types: white matter, ventricular system, cerebellum, extra-axial cerebrospinal fluid, cortical gray matter, deep gray matter, brainstem, and corpus callosum. Results: An intra-rater variability analysis suggests that the seven anatomical land-marks are sufficiently reliable. We find that the proposed atlas outperforms a normal fetal brain atlas for the automatic segmentation of brain 3D MRI of fetuses with SBA. Conclusions: We make publicly available a spatio-temporal fetal brain MRI atlas for SBA, available here: https://doi.org/10.7303/syn25887675. This atlas can support future research on automatic segmentation methods for brain 3D MRI of fetuses with SBA.

Background: Caudal block is a popular regional anesthesia technique in pediatrics for anesthesia and perioperative analgesia. Conventional landmark-based technique is a simple technique with good success rate but associated with complications such as dural puncture and venous injection. Ultrasound-guided caudal block is known to improve the success rate and reduce the complications noted with the landmark technique. We aimed to compare the success rates of caudal block in landmark- and ultrasound-guided techniques. Methods: One hundred and twenty-four children under 10 years admitted for infraumbilical surgeries were randomly allocated to Group L and Group U caudal block was administered based on landmarks in Group L and by using ultrasound in Group U. In both the groups, observations noted were success of caudal block, visibility and palpability of sacral cornu; identification of hiatus; first attempt success; number of attempts; block performance time; and complications. In Group U, ultrasound visualization of sacral hiatus, needle, and distension of sacral canal with injection was also noted. Results: Success rates were 81.8% and 92.1% in Group L and Group U, respectively (P = 0.045). Complications noted in Group L were blood tap (23.8%), subcutaneous swelling (15.2%), dural puncture (1.5%), and rectal perforation (1.5%). In Group U, only blood tap (3%) was the complication noted. Block performance was faster in Group L than Group U. There was no significant difference in the first attempt success rate and number of attempts. Conclusion: Ultrasound-guided caudal block improves the success rate, reduces complications, and ensures safety.

BACKGROUND: Despite their emerging therapeutic relevance, there are many discrepancies in anatomical description and terminology of the articular nerves supplying the human knee capsule. This cadaveric study aimed to determine their origin, trajectory, relationship and landmarks for therapeutic purpose. METHODS: We dissected 21 lower limbs from 21 cadavers, to investigate the anatomical distribution of all the articular nerves supplying the knee joint capsule. We identified constant genicular nerves according to their anatomical landmarks at their entering point to knee capsule and inserted Kirschner wires through the nerves in underlying bone at those target points. Measurements were taken, and both antero-posterior and lateral radiographs were obtained. RESULTS: The nerve to vastus medialis, saphenous nerve, anterior branch of obturator nerve and a branch from sciatic nerve provide substantial innervation to the medial knee capsule and retinaculum. The sciatic nerve and the nerve to the vastus lateralis supply sensory innervation to the supero-lateral aspect of the knee joint while the fibular nerve supplies its infero-lateral quadrant. Tibial nerve and posterior branch of obturator nerve supply posterior aspect of knee capsule. According to our findings, five constant genicular nerves with accurate landmarks could be targeted for therapeutic purpose. CONCLUSION: The pattern of distribution of sensitive nerves supplying the knee joint capsule allows accurate and safe targeting of five constant genicular nerves for therapeutic purpose. This study provides robust anatomical foundations for genicular nerve blockade and radiofrequency ablation.

Surgery of the brainstem is challenging due to the complexity of the area with cranial nerve nuclei, reticular formation and ascending and descending fibers. Safe entry zones are required to reach the intrinsic lesions of the brainstem. The aim of this study was to provide detailed measurements for anatomical landmark zones of the ventrolateral surface of the human brainstem related to previously described safe entry zones. In this study, 53 complete and 34 midsagittal brainstems were measured using a stainless caliper with an accuracy of 0.01 mm. The distance between the pontomesencephalic and bulbopontine sulci was measured as 26.94 mm. Basilar sulcus-lateral side of pons (origin of the fibers of the trigeminal nerve) distance was 17.23 mm, transverse length of the pyramid 5.42 mm and vertical length of the pyramid 21.36 mm. Lateral mesencephalic sulcus was 12.73 mm, distance of the lateral mesencephalic sulcus to the oculomotor nerve 13.85 mm and distance of trigeminal nerve to the upper tip of pyramid 17.58 mm. The transverse length for the inferior olive at midpoint and vertical length were measured as 5.21 mm and 14.77 mm, consequently. The thickness of the superior colliculus was 4.36 mm, the inferior colliculus 5.06 mm; length of the tectum was 14.5 mm and interpeduncular fossa 11.26 mm. Profound anatomical knowledge and careful analysis of preoperative imaging are mandatory before surgery of the brainstem lesions. The results presented in this study will serve neurosurgeons operating in the brainstem region.

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.

Background: The current standard followed for assessing central venous catheter (CVC) tip placement location is through radiological confirmation using chest X-ray (CXR). Placement of CVCs under electrocardiogram (ECG) guidance may save cost and time compared to CXR. Objective: The objective of this study is to compare the accurate placement of the CVC tip using anatomical landmark technique with ECG-guided technique. Another objective is to compare CVC placement time and postprocedural complications between the two techniques. Methods and Materials: A total of 144 adult individuals, who were critically ill and required CVC placement in the Emergency Department, were included for the study. Study duration was 6 months. Anatomical landmark and ECG-guided groups were assigned 72 participants each. Analyses were performed using t and Chi square-tests. Results: It was observed that 13 (18%) in the landmark technique were malpositioned as compared to none in the ECG-guided technique (P = 0.000). The landmark group had 22 (30.6%) participants with arrhythmias during the procedure, compared to none in the ECG-guided group (P = 0.000). The landmark group revealed that 30 (41.7%) of the CVC were overinserted and required immediate repositioning, compared to none in the ECG-guided group (P = 0.000). Conclusion: ECG-guided technique was found to be more accurate for CVC tip placement than the anatomical landmark technique. Furthermore, the ECG-guided technique was more time-effective and had less complications than the anatomical landmark technique. Hence, ECG-guided CVC placement is relatively accurate, efficient, and safe and can be considered as an alternative method to conventional radiography for confirmation of CVC tip placement.

Deep brain stimulation has become an option for advanced Parkinson's disease treatment since the 1990s, but the first reports are from Benabid's team, a French neurosurgeon, in the 1980s. The subthalamic nucleus (STN), more specifically its dorsolateral portion, is the most commonly stimulated brain area. One of the major aspects for a good surgical result is the accurate location of this target. Therefore, the present article aimed to identify landmarks that facilitate and refine the location of the STN using nuclear magnetic resonance imaging (NMRI) of the skull. In order to achieve this goal, a search for articles was performed using the PubMed and Science Direct online databases, and articles regarding the use of NMRI to target STN were included. The precise location of the dorsolateral portion of the STN is fundamental to achieve the best possible effect on motor symptoms and to minimize side effects. One of the most used location methods is the NMRI, associated or not with tomography or ventriculography. The location strategies can be classified as direct and indirect. Landmarks are among the indirect strategies, and the most important ones (red nucleus, Sukeroku sign, dent internal capsule sign, supramammillary commissure, mammillothalamic tract, and interpeduncular cistern) are described in the present article. The various landmarks can be combined to locate with more accuracy the dorsolateral portion of the STN and the ideal position of the electrodes to achieve the best possible clinical result.

Background: There is good evidence that ultrasound (US) increases the accuracy of needle placement for joint aspiration and injection. However, considerable uncertainty remains as to whether US-guided injections (USGI) achieve better clinical outcome in rheumatic conditions compared with landmark-guided injections (LGI), and how any effect on outcome relates to accuracy. Methods: We conducted a literature search using PubMed, yielding 810 references. After applying randomised controlled trials (RCTs), human studies and relevance to rheumatic conditions as eligibility criteria, abstract review produced 26 studies. Study design quality was assessed using the Jadad scale. Results: The median sample size of the 26 studies was 58.5 (range 20–244) patients. Median Jadad score was low at 2.5 (1–5). Only 6 RCTs had an effective double blinding method, with sham-US/blindfolding of patients and a blinded outcome assessor. Sixteen of 26 (61.5%) trials showed superior outcome of USGI compared to LGI for one or more outcomes measuring pain, function or range of movement. The 3 RCTs with the lowest risk for bias failed to demonstrate clear USGI superiority for the main clinical outcomes. In 2 of the 4 studies that assessed both accuracy and efficacy, USGI did not show greater clinical efficacy overall, although they had superior accuracy and accurate injections were associated with better outcome of at least one clinical criterion. Conclusion: The majority of trials suggest US guidance associates with superior outcome of injections. However, higher quality RCTs and trials with similar accuracy between the two techniques fail to support this. There is need for further trials with better design and adequate sample power.

Bagheri, Hassan/0000-0002-6126-9543, WOS: 000498042800020, PubMed: 31660021, The upper segment of sacrum is an important for screw insertions of unstable lumbosacral spine. Measurements of the S1-S2 as sacral wings, pedicles, sacral foraminas and sacral canal were taken from 87 sacrums. the mean depths of S1 pedicle and sacral wing were estimated as 25.8 +/- 2.3 mm and 50.1 +/- 1.7 mm, respectively. Angles screw trajectory of sacral pedicle anteromedial and sacral wing were measured as 29.6 +/- 0.9 degrees and 29.7 +/- 2.1 degrees, respectively. To avoid injury to the vascular structures anteriorly and nerve roots medially, depth and angle of screw trajectory is important for the entrance off pedicular screw placement to the S1.

We would like to thank Tran et al1 for their interest in our paper2. They expressed their concerns about two of the five anatomical landmarks we proposed to target with increased accuracy for genicular nerve ablation: the superior medial (SMGN) and the superior lateral (SLGN) genicular nerves. We would like to respond to the issues raised and to clarify some anatomical and methodological disagreements.

Introduction The incisive papilla is one of the most stable landmarks for assessing the original position of certain key teeth. To place anterior artificial teeth back in its original position such as in denture construction and full mouth rehabilitation cases vertical and horizontal distance from incisive papilla in different arch forms, imparts a significant role. The average distance will be helpful for arrangement of teeth in its original position which not only provides a pleasing appearance and normal function but also will save the dentists' chair side effort. Aim To determine the average vertical and horizontal distance of the maxillary central incisors from the incisive papilla in dentate individuals with different arch forms. Materials and methods Primary impressions and casts were made for 72 dentate patients, sorted into different arch forms and mid point of the incisive papilla was established. The vertical and horizontal distances were measured with the digital vernier caliper. The mean and standard deviation were subjected to Students t-test. Results The range of horizontal distance was 4-7 mm, 6-8 mm, 5-8 mm and vertical distance was 4-6 mm in ovoid, square and tapered arch forms respectively. Conclusion Horizontal distance of the maxillary central incisors from the incisive papilla varies in different arch forms whereas, vertical distance is almost same in all the arch forms.

Objective To study the ideal patient's head positioning for the anterior circulation aneurysms microsurgery. Method We divided the study in two parts. Firstly, 10 fresh cadaveric heads were positioned and dissected in order to ideally expose the anterior circulation aneurysm sites. Afterwards, 110 patients were submitted to anterior circulation aneurysms microsurgery. During the surgery, the patient's head was positioned accordingly to the aneurysm location and the results from the cadaveric study. The effectiveness of the position was noted. Results We could determine mainly two patterns for head positioning for the anterior circulation aneurysms. Conclusion The best surgical exposure is related to specific head positions. The proper angle of microscopic view may minimize neurovascular injury and brain retraction. Objetivo Estudar o posicionamento da cabeça para a cirurgia de aneurismas cerebrais da circulação anterior. Método Dividimos o estudo em duas partes. Inicialmente, dez cabeças de cadáveres frescos foram posicionadas e dissecadas de modo a expor, de maneira ideal, os principais sítios de aneurismas na circulação anterior do cérebro. Posteriormente, 110 pacientes foram submetidos a microcirurgia para clipagem de aneurismas cerebrais da circulação anterior. Durante as cirurgias, as cabeças foram posicionadas de acordo com a localização específica de cada aneurisma e o resultado obtido no estudo dos cadáveres. Cada paciente teve sua posição avaliada quanto a sua eficácia. Resultados Obtivemos basicamente dois padrões de posicionamento da cabeça para cirurgias de aneurismas cerebrais da circulação anterior. Conclusão A melhor exposição cirúrgica está relacionada à posição específica da cabeça para cada localização aneurismática. O ângulo de visão microscópica adequado minimiza lesões neurovasculares e a excessiva retração cerebral.

This paper proposes a review of the methods to detect and represent the human symmetry line. In the last years, the development of 3D scanners has allowed to replace the traditional techniques (marking based methods) with modern methodologies that, starting from a 3D valid discrete geometric model of the back, perform the posture and vertebral column detection based on a complex processing of the acquired data. The purpose of the paper is a critical discussion of the state of the art in order to highlight the real potentialities and the limitations still present of the most important methodologies proposed for human symmetry line detection.

Context: Comprehensive understanding of the anatomic position of pulp canal orifices and the measurements of the molar pulp space may maintain the pulp health during conservative tooth preparation and minimize the possibility of mishaps during endodontic therapy. Aims: The idea of the present study was to analyze the morphological measurements of anatomical landmarks in human maxillary first molar pulp chambers and evaluation of number of pulp canal orifices using three-dimensional spiral computed tomography (SCT). Subjects and Methods: One hundred and thirty extracted intact human adult maxillary first molars were chosen from the North Indian population and were analyzed using SCT in axial and coronal sections. Statistical Analysis Used: Standard deviation, mean, and coefficient of variance were calculated. Interobserver reliability was evaluated using kappa value to avoid any bias. Results: The results from our study showed that 69.23% of the sample teeth had four canal orifices, the mesial and distal pulp horns were present at an average distance of 0.80 ± 0.36 mm and 0.41 ± 0.34 mm, respectively, above the cementoenamel junction (CEJ), and the mean distance from the central groove of central fossa to furcation and the central groove of central fossa to the pulp chamber's roof was 8.37 ± 0.33 mm and 3.87 ± 0.29 mm, respectively. The average distance of the pulp chamber's floor from the furcation was found to be 2.47 ± 0.11 mm. The highest degree of variance was observed in case of relation of CEJ to pulp horns, i.e., 44.85% and 82.60%. Conclusions: The dimensions observed in this study and its resemblance to the various studies reported in literature shift the fundamental anatomic approach to a more systemic quantifiable approach to the endodontic maxillary first molar access preparation.

Dental implants are widely used for the rehabilitation of edentulous spaces. Diagnostic images of the surgical site is essential for preoperative planning, intra-operative assessment, and postoperative evaluation. At present, Cone-Beam Computed Tomography(CBCT) is the best imaging modality for qualitative and quantitative analysis of the surgical site for implant placement. It allows pragmatic planning and subsequent post operative evaluation with submillimetric accuracy. CBCT software enables simulation of implant placement to choose the ideal dimension, position and orientation. This article briefly describes why CBCT is crucial for dental implants and explains how to utilise its advantages. Radiological pictures of a few cases have been discussed to highlight the merits and demerits of this imaging modality for pre-surgical and post surgical evaluation of implant placement.

Background: Dental implants and metal fillings may cause artifacts in cone-beam computed tomography (CBCT) images and reduce image quality and anatomic accuracy. The purposes of this study are a subjective evaluation of anatomic landmarks and linear bone measurements after applying artifact removal (low–medium) option on CBCT images. Materials and Methods: In this cross-sectional study, thirty CBCT images from thirty qualified patients were selected in a private radiology center. Low and medium artifact removal was applied to images. Three radiologists assessed the visibility of the mandibular canal, mental foramen, and lamina dura in images. Crestal width and bone length were also measured in three groups of images and was compared by exact McNemar test. ICC test (two-way random model, absolute agreement types) was calculated for comparison of linear bone measurements in three images groups. P ≤ 0.05 was considered statistically significant. Results: Percent agreement of determining mental foramen (outline and location), mandibular canal (outline and location), and lamina dura between three groups of images were 100%, 100%, 83.3%, 96.7%, and 56.6%, respectively. The results of exact McNemar test revealed that medium artifact removal group had a statistical difference in lamina dura observation with none and low artifact removal groups (P < 0.001). Intraclass correlation coefficient showed no statistical differences in crestal width and bone length between groups (P < 0.001). Conclusion: Applying artifact removal does not affect the visibility of large anatomical structures and linear bone measurements, but delicate structures such as lamina dura may become less clear after artifact removal.

Introduction: Prosthodontic rehabilitation aims to achieve the best possible facial esthetic appearance for a patient. Attaining facial symmetry forms the basic element for esthetics, and knowledge of the midline of face will result in a better understanding of dentofacial esthetics. Currently, there are no guidelines that direct the choice of specific anatomic landmarks to determine the midline of the face or mouth. Most clinicians choose one specific anatomic landmark and an imaginary line passing through it. Thus, the clinician is left with no established guidelines to determine facial midline. Objective: The purpose of the study is to digitally determine the relationship of facial landmarks with midline of face and formulate a guideline for choosing anatomic landmark among Punjabi population. Materials and Methods: Three commonly used anatomic landmarks, namely nasion, tip of the nose, and tip of the philtrum, were marked clinically on 100 participants (age range: 21–45 years). Frontal full-face digital images of the participants in smile were then made under standardized conditions. Midline analysis was carried out digitally using an image analyzing software. The entire process of midline analysis was done by a single observer and repeated twice. Reliability analysis and one-sample t-tests were conducted. Results: The results indicated that each of the four landmarks deviated uniquely and significantly (P < 0.001) from the midlines of the face as well as the mouth. Conclusions: Within the limitations of the study, the hierarchy of anatomic landmarks closest to the midline of the face in smile was as follows: (1) Intercommissural midlines, (2) Tip of philtrum, (3) Nasion, (4) Tip of the nose, and (5) Dental midlines. The hierarchy of anatomical landmarks closest to the intercommissural/mouth midline was: (1) Tip of philtrum, (2) Tip of the nose, (3) Nasion, and (4) dental midline.

Purpose: While 3D patient-specific digital models are currently available, thanks to advanced medical acquisition devices, there is still a long way to go before these models can be used in clinical practice. The goal of this paper is to demonstrate how 3D patient-specific models of anatomical parts can be analysed and documented accurately with morphological information extracted automatically from the data. Part-based semantic annotation of 3D anatomical models is discussed as a basic approach for sharing and reusing knowledge among clinicians for next-generation CAD-assisted diagnosis and treatments. Methods: We have developed (1) basic services for the analysis of 3D anatomical models and (2) a methodology for the enrichment of such models with relevant descriptions and attributes, which reflect the parameters of interest for medical investigations. The proposed semantic annotation is ontology-driven and includes both descriptive and quantitative labelling. Most importantly, the developed methodology permits to identify and annotate also parts-of-relevance of anatomical entities. Results: The computational tools for the automatic computation of qualitative and quantitative parameters have been integrated in a prototype system, the SemAnatomy3D framework, which demonstrates the functionalities needed to support effective annotation of 3D patient-specific models. From the first evaluation, SemAnatomy3D appears as an effective tool for clinical data analysis and opens new ways to support clinical diagnosis. Conclusions: The SemAnatomy3D framework integrates several functionalities for 3D part-based annotation. The idea has been presented and discussed for the case study of rheumatoid arthritis of carpal bones; however, the framework can be extended to support similar annotations in different clinical applications.

Background and purpose: Accurate placement of an external ventricular drain (EVD) for the treatment of hydrocephalus is of paramount importance for its functionality and in order to minimize morbidity and complications. The aim of this study was to compare two different drain insertion assistance tools with the traditional free-hand anatomical landmark method, and to measure efficacy, safety and precision. Methods: Ten cadaver heads were prepared by opening large bone windows centered on Kocher's points on both sides. Nineteen physicians, divided in two groups (trainees and board certified neurosurgeons) performed EVD insertions. The target for the ventricular drain tip was the ipsilateral foramen of Monro. Each participant inserted the external ventricular catheter in three different ways: 1) free-hand by anatomical landmarks, 2) neuronavigation-assisted (NN), and 3) XperCT-guided (XCT). The number of ventricular hits and dangerous trajectories; time to proceed; radiation exposure of patients and physicians; distance of the catheter tip to target and size of deviations projected in the orthogonal plans were measured and compared. Results: Insertion using XCT increased the probability of ventricular puncture from 69.2 to 90.2% (p = 0.02). Non-assisted placements were significantly less precise (catheter tip to target distance 14.3 ± 7.4mm versus 9.6 ± 7.2mm, p = 0.0003). The insertion time to proceed increased from 3.04 ± 2.06min. to 7.3 ± 3.6min. (p

BackgroundThis study aimed to have international experts converge on a harmonized definition of whole hippocampus boundaries and segmentation procedures, to define standard operating procedures for magnetic resonance (MR)-based manual hippocampal segmentation.MethodsThe panel received a questionnaire regarding whole hippocampus boundaries and segmentation procedures. Quantitative information was supplied to allow evidence-based answers. A recursive and anonymous Delphi procedure was used to achieve convergence. Significance of agreement among panelists was assessed by exact probability on Fisher's and binomial tests.ResultsAgreement was significant on the inclusion of alveus/fimbria (P = .021), whole hippocampal tail (P = .013), medial border of the body according to visible morphology (P = .0006), and on this combined set of features (P = .001). This definition captures 100% of hippocampal tissue, 100% of Alzheimer’s disease-related atrophy, and demonstrated good reliability on preliminary intrarater (0.98) and inter-rater (0.94) estimates.DiscussionConsensus was achieved among international experts with respect to hippocampal segmentation using MR resulting in a harmonized segmentation protocol. published

The improvement in the knowledge of the main anatomical landmarks permits an evolution in the safety of the surgical treatment and a conceptual development of the geometrical anatomico-surgical characteristics of the infratemporal fossa. This conceptual evolution determines surgical and oncological advantages: firstly, improved comprehension of the anatomico-surgical limits of the resection and secondly the safeguarding of the oncological "en-bloc" dissection. The lateral approach of the infratemporal fossa gives a wider exposure of the surgical field, a shorter depth of work, a good control over the vessels and the possibility of carry out a microsurgical transfer. The surgical approaches correspond to the topographical location and the biology of the neoplasm in cases with infratemporal fossa and inferior compartment location the lateral transfacial approach is indicated. In cases with involvement of the superior compartment a lateral transcraniofacial subtemporal approach is necessary in order to remove the skull base. In cases with a neoplastic invasion of the skull base where the dura mater is the anatomical plane free from disease it is necessary to utilize an intradural approach. In patients with a secondary spread into the inferior compartment from the maxilla a combined antero-lateral transfacial approach is indicated. Finally, an orbitomaxillary involvement with secondary spread in the upper compartment of the infratemporal fossa necessitates an antero-lateral transcraniofacial subtemporal subfrontal approach.

International audience; In this paper, we present a computer-assisted method for facial reconstruction. This method provides an estimation of the facial shape associated with unidentified skeletal remains. Current computer-assisted methods using a statistical framework rely on a common set of extracted points located on the bone and soft-tissue surfaces. Most of the facial reconstruction methods then consist of predicting the position of the soft-tissue surface points, when the positions of the bone surface points are known. We propose to use Latent Root Regression for prediction. The results obtained are then compared to those given by Principal Components Analysis linear models. In conjunction, we have evaluated the influence of the number of skull landmarks used. Anatomical skull landmarks are completed iteratively by points located upon geodesics which link these anatomical landmarks, thus enabling us to artificially increase the number of skull points. Facial points are obtained using a mesh-matching algorithm between a common reference mesh and individual soft-tissue surface meshes. The proposed method is validated in term of accuracy, based on a leave-one-out cross-validation test applied to a homogeneous database. Accuracy measures are obtained by computing the distance between the original face surface and its reconstruction. Finally, these results are discussed referring to current computer-assisted reconstruction facial techniques.

International audience; In this paper, we focus on the automation of facial reconstruction. Since they consider the whole head as the object of interest, usual reconstruction techniques are global and involve a large number of parameters to be estimated. We present a local technique which aims at reaching a good trade-off between bias and variance following the paradigm of non-parametric statistics. The estimation is localized on patches delimited by surface geodesics between anatomical points of the skull. The technique relies on a continuous representation of the individual surfaces embedded in the vectorial space of extended normal vector fields. This allows to compute deformations and averages of surfaces. It consists in estimating the soft-tissue surface over patches. Using a homogeneous database described in [31], we obtain results on the chin and nasal regions with an average error below 1 mm, outperforming the global reconstruction techniques.

In this work, a new technique for symmetry line detection for non-erected postures, which can not be investigated with the other methods presented in the literature, is proposed. It evaluates the symmetry line by means an adaptive process in which a first attempt is modified step by step until the solution converges to the best estimation. The method here proposed is validated by analysing four different non-erected postures in which the spine does not lie onto sagittal plane, by the comparison with the traditional approach to symmetry line detection, having as reference the cutaneous marking. Results are analysed and critically discussed.

Identification of anatomical landmarks on skeletal tissue reconstructed from CT/MR images is indispensable in patient-specific preoperative planning (tumour referencing, deformity evaluation, resection planning, and implant alignment and anchoring) as well as intra-operative navigation (bone registration and instruments referencing). Interactive localisation of landmarks on patient-specific anatomical models is time-consuming and may lack in repeatability and accuracy. We present a computer graphics-based method for automatic localisation and identification (labelling) of anatomical landmarks on a 3D model of bone reconstructed from CT images of a patient. The model surface is segmented into different landmark regions (peak, ridge, pit and ravine) based on surface curvature. These regions are labelled automatically by an iterative process using a spatial adjacency relationship matrix between the landmarks. The methodology has been implemented in a software program and its results (automatically identified landmarks) are compared with those manually palpated by three experienced orthopaedic surgeons, on three 3D reconstructed bone models. The variability in location of landmarks was found to be in the range of 2.15–5.98 mm by manual method (inter surgeon) and 1.92–4.88 mm by our program. Both methods performed well in identifying sharp features. Overall, the performance of the automated methodology was better or similar to the manual method and its results were reproducible. It is expected to have a variety of applications in surgery planning and intra-operative navigation.

Background Back surface topography has gained acceptance in recent decades. At the same time, the motivation to use this technique has increased. From the view of the patient, the cosmetic aspect has played and still plays a major role as it provides a comprehensive documentation of cosmetic impairment. From the view of the medical practitioner, the aspect of reducing X-ray exposures in diagnosis and follow-up has been dominant and still prevails. Meanwhile, new aspects have emerged: due to the consequent three-dimensional view of the scoliotic condition, treatment success can be visualized convincingly. Clinical diagnosis is supported by information otherwise not supplied by X-rays, such as when functional examinations and diagnostic tests are recorded. Methods Like rasterstereography, most techniques of actual back surface measurement refer to photogrammetry and the triangulation method. However, with respect to the particular clinical application, a wide spectrum of implementations exists. Applications in a clinic require high accuracy of measurement in a short time and comprehensive analysis providing data to be used to supplement and compare with radiographic data. This is exemplified by rasterstereography; the procedures of surface analysis and localization of landmarks using curvatures and the reconstruction of the spinal midline will be described. Orthopaedic relevance Based on rasterstereographic analysis, different geometrical measures that characterize the back surface are given and underlying skeletal structures described. Furthermore, in analogy to radiological projection, a 3-D reconstruction of the spinal midline is visualized by a frontal and lateral projection, allowing comparison with pertinent X-rays. Conclusions Surface topography and, in particular, rasterstereography provide reliable and consistent results that may be used to reduce X-ray exposure. Unfortunately, the correlation of shape parameters with the radiological Cobb angle is poor. However, the wealth of additional applications substantially enhances the spectrum of clinical value.