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To assess the value of combined transvaginal/transabdominal ultrasonographic evaluation performed by experienced examiners for deep infiltrating endometriosis (DIE) lesions of the retrocervical (torus uterinus and uterosacral ligaments) and parametrial areas and summarize the features and anatomic criteria for identification of these lesions and their extent in the above-mentioned pelvic compartments.Retrospective study.A specialized endometriosis center in Avellino, Italy.A retrospective cohort of patients who underwent laparoscopic surgery for clinically suspected DIE between January 1, 2014, and December 31, 2018, with a dedicated ultrasound (US) evaluation performed no more than 1 month before the intervention.Preoperative US findings and surgical reports were reviewed. Using the findings of laparoscopic surgery as the gold standard, the sensitivity and specificity of preoperative US evaluation for retrocervical and parametrial endometriotic lesions were calculated with the corresponding 95% confidence intervals.A total of 4983 patients were included. US evaluation showed high diagnostic accuracy for DIE detection in the examined pelvic compartments, with sensitivity and specificity of 97% to 98% and 98% to 100%, respectively, for both retrocervical (torus uterinus and uterosacral ligaments insertion) and parametrial lesions.Parametrial extension of DIE indicates major surgical technical difficulties and risk of complications, and urologic and nerve-sparing procedures may be required in such cases. Preoperative evaluation of such scenarios will allow proper counseling of patients and facilitate adequate surgical planning in referral centers; moreover, when necessary, it can guide the constitution of a dedicated multidisciplinary surgical team as an alternative to treatment by a pelvic surgeon alone. Detailed imaging evaluation of DIE lesions and their extension is crucial for clinical management of affected patients. It can facilitate optimization of surgical timing and strategies, thereby potentially preventing ineffective, or even harmful, repeated procedures.

Background Occipital artery–posterior inferior cerebellar artery (OA–PICA) bypass is a challenging procedure and not frequently performed due to difficulties in occipital artery (OA) harvest. To facilitate the harvest, the intersection between the sternocleidomastoid and splenius capitis (known as the “OA triangle”) is used as the anatomical landmark to identify the OA segment that carry the highest risk of damage. This clinical study aimed to demonstrate the efficacy and safety of OA harvest using this landmark. Methods Eighteen patients who underwent the OA harvest using the OA triangle as a landmark for treatment of vertebral artery and PICA aneurysms were retrospectively evaluated for the safety and patency of OA after the harvest and OA–PICA bypass. Results Eighteen patients experienced ruptured and unruptured vertebral artery and PICA aneurysms. Thirteen patients (72.2%) underwent OA–PICA bypass and 5 patients (27.8%) did not undergo bypass. The OA was completely harvested without damage in all patients. After the harvest, the OA was patent in 17 patients (94.4%) and was occluded in one patient due to vasospasm, who then underwent recanalization resulting in good patency of the OA–PICA bypass thereafter. The patency rate of the OA–PICA bypass was 100%. Conclusions The OA triangle, which is the anatomical landmark of the proximal end of the transitional segment of OA, facilitated the OA harvest using the distal-to-proximal harvest technique with safety and good patency. To the best of our knowledge, this is the first study of OA harvest in the clinical cases.

Summary Background The measurement of anatomical structures is critical in plastic and reconstructive surgery. However, few detailed and standardized measurements have been widely used in the periorbital region. This study aimed to evaluate the feasibility of a novel detailed and standardized protocol with 2D and 3D technologies, and explore the relationship between them and direct measurements. Methods Fifty healthy Caucasians (100 eyes) between 20 and 68 years old were recruited and captured for 3D photographs by VECTRA M3 3D Imaging System. Subsequently, 24 landmarks were located on each 3D photographs following a standardized protocol, and then 19 linear and 3 angular periorbital variables were measured. Furthermore, two-dimensional (2D) and direct measurements were conducted on each subject and compared with 3D measurements and one another. Results The grand r means across all measurements were 0.77, 0.78, and 0.88 for direct vs. 2D values, direct vs. 3D values, and 3D vs. 2D values, respectively. The mean absolute differences were 1 mm (ranging from 0.2 mm to 3.7 mm) between direct and 3D measurements, 1 mm (ranging from 0.04 mm to 2.4 mm) between direct and 2D measurements, and 1 mm and 6.6° (ranging from 0.04 mm or 0.5° to 3 mm or 12.8°) between 2D and 3D measurements. Conclusions This study verified the feasibility of this detailed and standardized landmark localization protocol for assessing the periorbital morphology with 2D and 3D technologies. This protocol may work as a bridge communicating with all studies involving any of the three technologies in the future.

Masseter injections for cosmetic or pathological reasons are increasingly common, as are filler injections using dual or multiplane techniques in the lateral facial regions or for jawline contouring. The occurrence of blindness following these procedures often remains unexplained. This study aimed to determine the anatomical explanation for this debilitating complication by investigating the transverse facial artery and its relation to the masseter. For this purpose, we dissected 35 cheek specimens with latex injections and 10 specimens without latex. The external carotid artery was dissected up to its bifurcation into the maxillary and superficial temporal arteries. Results showed that the transverse facial artery arose from the superficial temporal or external carotid artery that runs between the zygomatic arch and the parotid duct. Three types of transverse facial arteries were observed: type I: a short artery that did not extend beyond the masseter muscle; type II: a transverse artery that ran to the nasolabial fold and anastomosed to the facial artery; and type III: a sizable transverse artery that substituted the hypoplastic facial artery, continued as the angular artery, and then anastomosed to the dorsal nasal artery. Knowledge of these three types of transverse facial arteries is a prerequisite to study the vascular territory. Type III provides an explanation for the occurrence of blindness after lateral face injections. We consequently define a line that runs from the tragus to the outer quarter of the upper lip as the risk area, while the safe zone is located on either side of this line.

Summary The nasal aesthetic subunit principle has been widely accepted as the standard for nasal reconstruction with forehead flaps. However, in our experience, one's impression of a reconstructed face can easily be represented by the nose's entire appearance rather than a single nasal component. Accordingly, we hypothesized that total nasal reconstruction focusing more on the facial aesthetic subunit principle would be superior to focal nasal subunit partial reconstruction. Here, we investigated the indication range of total nasal reconstruction and analyzed its effectiveness. Between July 2006 and December 2017, 32 patients who underwent total or subtotal nasal reconstruction were recruited. The total nasal reconstruction group (n = 20) was treated according to our modified facial aesthetic unit concept, while the subtotal reconstruction group (n = 16) was treated according to the nasal aesthetic subunit principle. Using retrospective reviews, we compared surgical details and aesthetic, and functional outcomes with visual analog scale scores. In aesthetic evaluation, nose contour (p = 0.009), nasal symmetry (p = 0.001), and nostril shape (p = 0.041) were superior in the total nasal reconstruction group. Satisfaction regarding the nose (p = 0.036) was significantly higher than that regarding the forehead and labial folds in the total group. Regarding function, there were no significant intergroup differences in nasal airflow, snoring, or olfaction. We suggest that total nasal reconstruction is not a strategy to avoid because of its aggressive nature. For selected suitable patients, the use of the total nose reconstruction focusing on our one nose concept can be a successful surgical option, and the reconstructed nose can be visualized as a real part of the face.

Since its initial description in 1996 by Yii and Niranjan, the internal pudendal perforator flap (also known as the Singapore flap, the gluteal fold flap, and the lotus petal flap) has become a workhorse in perineal soft tissue reconstruction. In 2001, Hashimoto described the presence of three to five perforators in the perineal anogenital triangle. The ischial tuberosity has thus become a useful anatomic landmark for the safe boundary of medial dissection during flap elevation, in order to avoid damaging the perforator vessels. The objective of the present study was to evaluate the perforators’ positions within the anogenital triangle by using color Doppler ultrasound. In a study of 15 subjects in the lithotomy position, we identified a total of 24 perforator vessels with a diameter greater than 5 mm. We noted the vessels’ positions using orthonormal measurements, according to the distance from the midline and the distance on a straight line between the two ischial tuberosities (i.e. consistent bony anatomic landmarks that are independent of the patient's height and body mass index). The mean distance between the ischial tuberosity and the internal pudendal perforator was 27.3 mm. Based on our present results, we consider that routine ultrasound identification and dissection of the perforators is not always required before pudendal flap harvesting. This decreases the operating time and simplifies the flap harvesting procedure.

Objective To provide precise description of the dorsal and ventral roots orientation along with the main spinal cord anatomical measurements and their segment-specific variations. Patients and Methods We collected and analyzed the measurements of the spines, spinal cords, and dorsal and ventral roots (C2-L5) of nine adult cadavers (five males and four females). Results This study for the first time provides analysis of the dorsal and ventral roots orientation along with spinal cord anatomical measurements and their segment-specific distribution. The results of this study showed less variability in rostral root angles compared with the caudal. Dorsal and ventral rootlets were oriented mostly perpendicular to the spinal cord at the cervical level and had more parallel orientation to the spinal cord at the thoracic and lumbar segments. The number of rootlets per root was greatest at dorsal cervical and lumbar segments. Spinal cord transverse diameter and width of the dorsal columns were largest at cervical segments. The strongest correlation between the spinal cord and vertebrae structures was found between the length of intervertebral foramen to rostral rootlet distance and vertebral bone length. Conclusion These results demonstrate consistent variation in spinal cord anatomical features across all tested subjects. The results of this study can be used to locate spinal roots and main spinal cord landmarks based on bone marks on computed tomography or X-rays. These results could improve stereotactic surgical procedures and electrode positioning for neuromodulation procedures.

Current decision about when to operate abdominal aortic aneurysms (AAAs) is based only on the maximum aneurysm diameter (MAD). However, small aneurysms still rupture and we can observe very large AAA without any symptom. A simple morphologic analysis could be a tool to assess the risk of rupture. The main objective of this study was to assess the relevance of ratios between MAD and healthy aorta on computed tomography (CT) as a risk factor of AAA rupture. The secondary objective was to evaluate CT signs as risk factors of AAA rupture.Retrospective observational bicentric study comparing CT scans of a ruptured AAA group and a control group treated electively was conducted. Appariement 1:1 based on MAD was applied. Ratios between healthy aorta diameters at several levels, celiac trunk (CTR), superior mesenteric artery (SMA), highest renal artery (RA), and the MAD were calculated. The presence of blebs, crescent signs, ruptures of calcifications of the aneurysm sack, and draped aorta were notified.From 2010 to 2016, 38 ruptured AAA and 38 controls were included. Ratios were superior in the rupture group, respectively: MAD/CTR [2.77 (±0.5) versus 2.58 (±0.4) P 0.095], MAD/SMA [2.92 (±0.7) versus 2.74 (±0.5) P 0.194], and MAD/RA [3.02 (±0.70) versus 2.76 (±0.5) P 0.054] but not significatively. Receiver operating characteristic curve analysis demonstrated optimal threshold to detect rupture at 2.8 for the ratio MAD/CTR (area under the curve (AUC) 0.593, sensitivity 47.4%, specificity 78.9%), at 3.3 for the ratio MAD/SMA (AUC 0.564, sensitivity 31.6%, specificity 92.1%), and at 3.3 for the ratio MAD/RA (AUC 0.591, sensitivity 31.6%, specificity 94.7%). Bivariate analysis for rupture risk factor showed significance for the three ratios (MAD/CTR 2.8 [OR = 11 (1.42; 85.20) P 0.0217], MAD/SMA 3.3 [OR = 10 (1.28; 78.12) P 0.0281], and MAD/RA3.3 [OR = 11.00 (1.42; 85.20) P 0.0217]). One scannographic sign was more present in the rupture group: crescent sign 36.8% versus 5.3%, P = 0.0007, as well in bivariate analysis [OR = 7 (1.59; 30.80) P 0.0326].In our experience, specific ratios when they exceed calculated threshold, seem to be more prone to rupture. We could consider that these measures, easy to apply in clinical practice, would be complementary keys for rupture risk individual assessment.

Objectives 1) Determine the concurrent validity of using automated 2D video analysis relative to 3D motion capture for assessing frontal and sagittal-plane knee kinematics during landing, 2) compare the accuracy of visually estimating joint center locations (2D Manual) with computing joint center locations using anatomical markers (2D Automatic), and 3) compare landing kinematics between a controlled laboratory setting and a non-laboratory setting. Design Validity/repeatability study. Settings Biomechanics research laboratory and non-laboratory athletic facility. Participants Thirty uninjured recreational athletes. Main Outcome Measures Peak knee flexion, knee flexion range of motion, peak knee frontal plane projection angle, and knee frontal plane projection angle range of motion during bilateral and unilateral landing were measured simultaneously in 3D using motion capture and in 2D using two low-cost video cameras during the first study session (biomechanics research laboratory), and in 2D only during the second study session (non-laboratory athletic facility). Results There was good to excellent agreement between 3D motion capture and both 2D Manual (ICC = 0.86–0.99) and 2D Automatic (ICC = 0.89–0.99) video analysis methods. There was good to excellent agreement between data collected in a laboratory and non-laboratory setting (ICC = 0.75–0.95). Conclusion The methods introduced in this study are inexpensive, reliable, and feasible for use in non-laboratory settings.

Background The inferolateral triangle is a surgical skull base triangle used as a neurosurgical landmark. There are few reports of its measurements with little attention paid to anatomic variations. Methods The inferolateral triangle was measured in 10 adult human cadaveric heads via dissection then direct measurement and 5 participants undergoing neuroimaging using tracing features. Results In the cadavers, mean lengths (mm) of the superior, anterior, and posterior borders were 17.0 (±5.5), 12.9 (±1.7), and 17.8 (±3.3), respectively, with mean area of 97.85 (±28.17) mm2. In the participants, mean lengths (mm) of the superior, anterior, and posterior borders were 17.35 (±4.01), 14.36 (±1.36), and 18.01 (±2.43), respectively, with mean area of 113.6 (±25.46) mm2. No statistical difference in triangle areas between groups was found. Conclusions Intimate understanding of the inferolateral triangle is essential to skull-based surgery; knowing its anatomy and variations aids in surgical planning and understanding of regional pathology.

Objective We analyzed cortical landmarks, trajectory of approach, and various fiber tracts in the vicinity of our earlier described approach through the orbital/basal surface of the frontal lobe to access tumors located in the region of the caudate nucleus. We also present a new lateral orbital trajectory to approach these tumors. Methods The orbital surfaces of 3 formalin fixed and frozen cadaveric brain specimens were dissected to decipher the white fibers in the region of the caudate nucleus. Safe trajectories to lesions of the head of the caudate nucleus were identified, and the anatomic landmarks of the approach were evaluated. Three patients with caudate head tumors were operated using this approach. Results The caudate head lies at an average distance of 34 mm from the tip of the frontal pole, 24 mm from the basal medial orbital surface of the frontal lobe, 35 mm from the basal lateral orbital surface, and 37 mm from the superior surface of the frontal lobe. Two avenues were identified to approach the caudate head: one by making a cortical incision in the lateral orbital gyrus (lateral orbital approach), and the second by making a corticectomy in the medial orbital gyrus (medial orbital approach) in line with the temporal pole. All 3 patients were operated successfully using this approach. Conclusions Surgical approach to the caudate head through the orbital surface of the frontal lobe as described by us provides the shortest trajectory and safe surgical route to access tumors of the caudate nucleus.

Optimal catheter tip position of a totally implantable venous access port (TIVAP) is important to maintain its function and to avoid severe complications. In this study, we aimed to assess the reliability of a modified surface measurement method to determine optimal tip position of a TIVAP catheter inserted through the right subclavian vein.Clinical and radiologic information of 105 patients who underwent TIVAP implantation through the right subclavian vein was collected retrospectively. The length of the implanted catheter was determined by a modified surface measurement method, as follows. The distance from the puncture point (point A) to the middle point of the sternal notch (point B), then from the middle point of the sternal notch (point B) to the middle point of Louis angle (point C) was added up. The equation for the catheter length is given by catheter length (cm) = AB + BC + 3. Postprocedure plain chest radiography (CXR) and enhanced chest computed tomography (CT) were used to check the catheter tip position and to calculate optimal position rate. Distance from the carina to the catheter tip and the length of the vertebral body unit were measured on both CXR and CT. Distances from carina to caval-atrial junction (CAJ) and from catheter tip to CAJ were measured on CT.Mean length of the implanted catheter of all patients was 17.0 ± 0.7 cm (male vs female, 17.3 ± 0.5 cm vs 16.7 ± 0.7 cm; P .001). On CXR, a catheter tip located within 2.4 vertebral body units below the carina was identified as the optimal position, and the optimal position rate was 97.1% (102/105 cases). On CT, two definitions of optimal position were used: within 2 cm above or below the CAJ and within 2 cm above or at the CAJ; the optimal position rate was 92.4% (97/105 cases) and 78.1% (82/105 cases), respectively. Median follow-up time was 9.4 months. During the follow-up, no severe cardiac complication was recorded.The modified surface measurement had high reliability in determining the optimal catheter length to accurately place the tip in the superior vena cava near the CAJ.

Introduction This study assessed the impact of dosimetry to both the target and normal tissue when either bony anatomy (BA) or prostate (PRO) was used as surrogates for image guidance for pelvis and prostate radiotherapy using a dose accumulation process. Methods Thirty patients who were prescribed 50–54Gy to the pelvic lymph nodes (PLN) and 78Gy to the prostate/seminal vesicles were included. Daily acquired CBCTs were rigidly registered to the CT using BA and PRO to simulate two different treatment positions. The accumulated delivered dose (DAcc) of PLN, prostate, bladder and rectum for each surrogate were compared with the planned dose. Deviation from the planned dose (ΔDAcc-Plan) of >5% was considered clinically significant. Results Prostate was displaced from bony anatomy by > 5 mm in 96/755 fractions (12.7%). Deviation between the mean DAcc and the planned dose for PLN and prostate was 0.2). In contrary, DAcc for rectum D50 was significantly greater than the planned dose when BA was used (Mean ΔDAcc-Plan = 6%). When examining individual patient, deviation from the planned dose for rectum D50 was clinically significant for 18 patients for BA (Range: 5–21%) and only 8 patients for PRO (Range: 5–8%). Conclusions The use of either BA or PRO for image guidance could deliver dose to PLN and prostate with minimal deviation from the plan using existing PTV margins. However, deviation for rectum was greater when BA was used.

Objective The aim of this study was to define the structural relationship between the arcuate eminence (AE) and a known fixed external bony landmark, the root of the zygoma (ZR), and to determine its reliability as a consistent guide for guiding surgical approaches. To our knowledge, this is the only anatomical study to quantify the relationship between the AE and the ZR. Method Twenty-one dry temporal bones were measured using digital calipers. The distance from the posterior aspect of the ZR to the midpoint of the AE was measured. Additionally, the anteroposterior distance between the ZR and AE and vertical distance between the two structures were measured. Student's t-test was used to compare the left and right sides. Result An AE was found in every specimen. The mean ZR to AE distance was 30.9 mm. On most sides (91%), the ZR was located more inferiorly than the AE with a mean distance of 3 mm between the two structures. The mean distance between the AE and ZR was 17 mm. On all sides, the AE was located posterior to the ZR. No significant differences were found between sides. No anatomical variations or pathological conditions were noted in any of the specimens. Conclusion The ZR is an easily identifiable and consistent bony landmark often used by skull base surgeons. In this investigation, we measured the anatomical relationships between the ZR and AE. Such data might assist in planning surgical trajectories and minimizing complications when skull base pathologies are approached.

Objective The specific anatomic characteristics of the iliac veins are often important reasons for stent failure. However, to the best of our knowledge, the inherent angles and configurations of the iliac veins have not been thoroughly studied. Methods Fifty patients without venous diseases who had undergone computed tomography urography for diagnosis of urolithiasis were included in this study. The pathways of the iliac veins were mapped out, and the major angles were measured. The factors associated with steep angles were also evaluated. Results There were two relatively constant angles on the right side and three on the left side along the common femoral vein, external iliac vein, and common iliac vein. All these were measured with the patients in the supine position. The angles at the inguinal region (γ) and internal-external iliac vein confluence (β) were at similar sites for both sides. There was a third angle in front of the fifth vertebra for the left side (α). The γ angle was 125.03 ± 11.68 degrees for the right side and 122.26 ± 9.64 degrees for the left side. The β angle was 136.91 ± 14.24 degrees for the right side and 125.61 ± 20.76 degrees for the left side. According to the β angle of the left side, the iliac veins could be categorized into three types. For type I, the angle was >150 degrees (14% [7/50]). For type II, it was 120 to 150 degrees (50% [25/50]). For type III, it was ≤120 degrees (36% [18/50]). The angles between the anterior border of the fifth vertebra and pelvic inlet plane (0.866; 95% confidence interval, 0.777-0.966) and age (1.087; 95% confidence interval, 1.004-1.177) were related to type III configurations on multilogistic regression analysis. Conclusions There were several relatively constant angles along the pathway of the iliac veins. The pathway of the left side was more complex than that of the right side. This difference in the angles might be related to the patients' age and bone structures. These angles should be considered in planning iliac vein stenting as well as in designing stents specifically for the iliac veins.

Thalassemia is the most common hereditary blood disorder across the world. This study aimed to identify some mandibular features of thalassaemic patients and compare them with unaffected counterparts.This retrospective case-control study was carried out on lateral cephalograms of 60 subjects (26 males, 34 females) with class II malocclusion and age range of 11 to 15 years. The control group consisted of 60 non-thalassaemic subjects with class II malocclusion and similar chronological age, gender and vertical facial dimension. Based on the Jarabak index, the case and control subjects were classified into hyperdivergent, normodivergent and hypodivergent growth patterns. Four linear (ramus height, ramus width, mandibular depth, and antegonial notch depth) and 3 angular (symphyseal angle, gonial angle, and mandibular arc angle) cephalometric parameters were measured to represent mandibular morphology. The data were analysed using Chi-square test and Student's t-test.No significant difference was found in linear measurements between thalassaemic patients and controls. The symphysis angle was significantly greater and the mandibular arc angle was significantly smaller in the total thalassaemic sample than the control individuals (P0.001 and P=0.004, respectively). The difference in symphysis angle was significant in both hyperdivergent and normodivergent subjects (P=0.004 and P=0.002, respectively), whereas the difference in mandibular arc angle was only significant in the normodivergent subgroup P=0.001).The smaller mandibular arc angle in the thalassaemic sample suggests a more superior than posterior growth direction of condyles compared with healthy individuals. The difference in symphyseal angle represents inherent differences in chin morphology between thalassaemic subjects and controls.

Background Intraoperative imaging is used to address the challenges of parathyroidectomy, but no standard modality has been established. This study aimed to assess whether carbon nanoparticle injection is useful in localizing parathyroid glands (PGs) during parathyroidectomy. Methods Patients who underwent total parathyroidectomy (TPTX) between September 2015 and November 2018 were included. The operative duration and intact parathyroid hormones (iPTH) were analyzed. Results A total of 61 patients were included; of these, 32 with carbon nanoparticle injection (TPTX + CN group) and 29 without (TPTX group). The operative duration in the TPTX + CN group was significantly shorter (90.6 ± 21.2 vs 101.4 ± 19.4 min, P = 0.042), which is more apparent in those with normal sized PGs. For those with four enlarged PGs, iPTH levels on 1 day and 1 year postoperatively were significantly lower in the TPTX + CN group (P = 0.032 and P = 0.036, respectively). Conclusion Carbon nanoparticles are useful in the identification normal sized PGs and complete resection of enlarged PGs.

The paramedian supracerebellar craniotomy is an underrecognized route to the midline and paramedian regions of the upper posterior brainstem. As compared with its midline supracerebellar counterpart, this less disruptive approach preserves the majority of the midline bridging veins, requires less cerebellar retraction, and is significantly more efficient. In this offering, I will emphasize the realities of this flexible route and its remarkable advantages in reaching deep-seated lesions.

Background Intravascular ultrasound (IVUS) provides endoluminal views and cross-sectional images of carotid arteries but lacks overview of vascular territory provided by angiography. Co-registration of IVUS with angiographic images may provide the potential to navigate both imaging modalities in a synchronous manner. The objective of this study is to evaluate the feasibility and accuracy of co-registering both imaging modalities in the carotid vasculature of the neck. Methods Fourteen patients with 15 cervical carotid artery lesions underwent angiography and subsequent treatment. In each case, an IVUS catheter was advanced to the target lesion and a reference angiography sequence was acquired. This was followed by an electrocardiography-triggered fluoroscopy sequence that was initiated upon IVUS catheter pullback. IVUS data collected during pullback were registered with fluoroscopy and evaluated for error and clinical usability. Results A total of 32 landmarks were identified that demonstrated reasonable agreement during IVUS–angiography co-registration. There was a mean registration error distance of 3.36 mm (SD 2.82 mm) between targets. The longitudinal extent and severity of the disease through the target segment could be easily evaluated after co-registration. Conclusion Semiautomatic tracking and co-registration of angiography and IVUS is a new technology and has the potential to increase the use of IVUS in carotid disease and to proivde the opportunity to optimize procedural outcomes.

Effective epidural needle placement and injection involves accurate identification of the midline of the spine. Ultrasound, as a safe pre-procedural imaging modality, is suitable for epidural guidance because it offers adequate visibility of the vertebral anatomy. However, image interpretation remains a key challenge, especially for novices. A deep neural network is proposed to automatically classify the transverse ultrasound images of the vertebrae and identify the midline. To distinguish midline images from off-center frames, the proposed network detects the left-right symmetric anatomic landmarks. To assess the feasibility of the proposed method for midline detection, a data set of ultrasound images was collected from 20 volunteers, whose body mass indices were less than 30. The data were split into two segments, for training and test. The performance of the proposed method was further evaluated using fourfold cross validation. Moreover, it was compared against a state-of-the-art deep neural network. Compared with the gold standard provided by an expert sonographer, the proposed trained network correctly classified 88% of the transverse planes from unseen test patients. This capability supports the first step of guiding the placement of an epidural needle.

Extraforaminal vertebral anomalies involve entry at cervical transverse foramina other than at C6 and can appear with other anatomic variations along the V2 segment. Such unexpected vessel courses can have implications on surgical planning. We sought to evaluate the incidence of anomalous V2 segment entries, as well as their associations with vessel dominance, medialization, and C7 pedicle width.We conducted a retrospective study on 1000 consecutive computed tomography angiograms, documenting level and laterality of vessel of entry, as well as vertebral dominance patterns. Patients with rostral C4 anomalies were assessed for medialization. The pedicle widths ipsilateral to caudal C7 anomalies were compared with those of contralateral and matched controls.A total of 157 patients were identified with extraforaminal entries, with 25 having bilateral findings. The most common alternative entry was at C5 (70.3%), followed by C4 (17.6%) and C7 (11.5%). Among patients with unilateral anomalies, there was an increased representation of contralateral vertebral dominance, relative to ipsilateral dominance (79.6% vs 20.4%, P0.0001). Among anomalous C4 entries, vertebral medialization was seen along the right (35%) and left sides (23.1%) spanning C6-T1. Among C7 anomalous entries there was no statistical difference in pedicle width.Extraforaminal anomalies may be more frequent than previously reported and are important considerations during subaxial cervical spine surgery planning. Particular attention should be paid to the contralateral dominance pattern within this subgroup. In patients with anomalous V2 segment entries, adherence to the standard, anatomic landmarks remains desirable.

Background The prevalence of a bovine aortic arch configuration is higher in patients treated for thoracic aortic aneurysms and type B dissection; its prevalence in aortic isthmic trauma has not been described. Methods A case control study was performed comparing consecutive patients treated at our institution for acute isthmic aortic transection after blunt trauma between 2002 and 2019 and a control group of consecutive sex-matched individuals undergoing imaging for nonaortic disease. Imaging and clinical findings were reviewed. Subjects were divided into bovine and nonbovine groups and prevalence was compared. The length of the aortic segment between the left subclavian artery (LSA) and the next proximal great vessel was measured in the control population and a comparison was performed between bovine and nonbovine aortic arch subjects. Results Thirty-three consecutive (30 male) patients were reviewed, 66 individuals (60 male) were included in the control group. A higher incidence of bovine arch in trauma patients was found: 57.6% vs. 34.8% (P = 0.007). The median (range, mm) and mean (SD) distance between the bovine trunk and the LSA were 13 mm (2–27) and 12.4 mm (5.9), respectively, compared with 5 mm (1–27) and 7.8 mm (6.1) between the left common carotid and LSA in nonbovine aortic arches (P Conclusion A higher incidence of bovine arch in patients reaching out for surgical treatment for traumatic isthmic aortic transection was found in our population. Clinical interpretation of this finding can lead to several alternatives. Confirmation with larger series and data on prevalence of this anatomic variation in nonsurvivors is needed to provide a better understanding of this finding.

In standard lateral wrist radiographs, the radiocarpal joint is often obscured because of the angulation of the radial styloid process. A modified lateral projection at a 20° angle has been shown to demonstrate the distal radius in profile in postoperative patients without superimposing of the orthopedic hardware used in open reduction and internal fixation procedures over the wrist joint. We assessed whether this 20° axial-lateral view is advantageous in a wider patient group.Consenting adults receiving wrist radiographs in a tertiary hospital radiology department for any indication underwent posteroanterior, posteroanterior-oblique, 0° lateral, and 20° lateral views. A musculoskeletal radiologist and a radiology technologist, blinded to clinical data and to which view was 0°/20°, both evaluated 0°/20° images in random order for whether the radiocarpal joint was obscured by radial styloid, radiocarpal articular margins, or ulnar styloid process, and which view was preferred.In 124 cases, the radiocarpal joint was shown clearly on more 20° than 0° views (75/124 vs. 23/124, P.001). Orthopedic hardware obscured joint lines in fewer 20° than 0° views (12/124 vs. 28/124, P.001). There was a trend to the ulnar styloid process obscuring part of the radiocarpal joint less in 0° view (28/124 vs. 78/124 in 20°; P = .088), primarily in 20° laterals of wrists with positive ulnar variance. The 20° view was preferred by the radiologist in 76% (95/124) and preferred by the technologist in 83% (104/124).The 20° lateral view was superior to the current 0° lateral view in a wide range of patients, with the radiocarpal joint obscured significantly less by hardware or adjacent anatomy, and preferred by both the blinded radiologist and technologist.

Objective Localization of the temporal horn of the lateral ventricle (TH) may be required during temporal lobe and ambient cistern surgery. Most available anatomic landmarks for TH localization are based on adjacent cortical landmarks that are inherently variable or subtle. This study aimed to localize the anterior tip of the TH relative to adjacent bony landmarks. Methods The TH was exposed on 21 sides of 11 cadaveric heads via removal of the middle temporal gyrus. Two lines were defined: (1) a perpendicular line to the zygomatic arch projected from the anterior concavity of the posterior zygomatic root (line A), and (2) a parallel line passing through the anterosuperior corner of the external auditory canal (line B). Sagittal distances from lines A and B to a parallel line passing through the anterior recess of the TH (line H) were measured. Results Mean (standard deviation) distances from lines A and B to line H were 13.3 (2.5) mm and 11.9 (2.2) mm, respectively. Line H was at 53% (8%) of the line A–line B interval measured from line A. The best way to search for the TH was to start approximately 15 mm posterior to line A and progress posteriorly such that a more posteriorly located TH tip would not be missed. Conclusions The zygomatic-meatal landmark is a reliable tool to localize TH during various approaches. It is independent from the approach trajectory. This landmark may be used as an ancillary tool in conjunction with other cortical landmarks and image guidance.

Summary Objective Understanding craniofacial growth and development is important for accurate diagnosis, treatment planning and post-treatment evaluation of orthodontic cases. Paramount to this is knowledge of the cranial base growth and development, since it is the foundation upon which the remaining facial structures develop. The purpose of this study was to analyse different anatomical structures in the posterior cranial base and determine its changes during the adolescent years (13–15 year of age) using CBCT. Materials and methods Sixty CBCT images of the adolescent population that received orthodontic treatment at two time-points (mean age T1: 13.1 years/T2: 14.6 years) were used to assess growth related dimensional changes using 33 selected landmarks. Inter-rater, intra-rater and accuracy of 33 selected landmarks in the posterior cranial base and surrounding area were then evaluated via three-dimensional (3D) cone-beam computed tomography (CBCT). Linear differences were then calculated among the different landmarks to determine the changes present in the sample. Results The selected landmarks in the posterior cranial base and surrounding area were found to be reliably and accurately located in 3D. Over the growth period studied (17.5 months), minor statistically significant changes occurred, but they were deemed clinically irrelevant. Conclusions The studied landmarks in the posterior cranial base and surrounding area showed minor clinically insignificant changes over the study period. The observed changes could be attributed to measurement error. The posterior cranial base is deemed to be stable in all three dimensions of study during the adolescent growth period studied.

Purpose This study aimed to (1) quantitatively analyze the fibular footprints of the lateral collateral ligament (LCL) and popliteofibular ligament (PFL) and (2) evaluate whether a fibular tunnel can restore the LCL and PFL fibular footprints simultaneously without modification in anatomic posterolateral corner reconstruction of the knee. Methods In 20 cadaveric knees, anatomic characteristics, such as diameter, location and relationship with anatomic landmarks, of the LCL and PFL footprints were analyzed. Subsequently, a fibular tunnel that connected the LCL and PFL footprint centers was created with 1.5 mm drill bit, and tunnel depth, which is defined as the distance between the tunnel and the nearest cortex, was evaluated. An additional tunnel from the anteroinferior border of the LCL footprint to the posteroinferior border of the PFL footprint was created, and its tunnel depth was evaluated as well and compared with that of the original tunnel. Results The LCL footprint was longitudinally ovoid (8.4 ± 1.0 × 13 ± 1.0 mm), and its inferior margin corresponded well with the lateral apex of the fibula (distance, 1.0 ± 0.7 mm). The PFL footprint was round (9.7 ± 1.3 × 9.0 ± 1.1 mm), and its center was very close to the tip of the fibular styloid process (1.2 ± 0.8 mm). The tunnel depth of the original fibular tunnel was 1.8 ± 0.7 mm, and it was very shallow for tunnel reaming. On the contrary, the tunnel depth of the modified fibular tunnel (6.4 ± 1.1 mm) was significantly higher than that of the original tunnel (P Conclusions A single fibular tunnel cannot reproduce the LCL and PFL footprint centers simultaneously because the trajectory is too close to the cortex. A modified fibular tunnel, using the margins of the footprints, is recommended to avoid cortical blowout. Clinical Relevance A modified fibular tunnel that covers only portions of the LCL and PFL footprints, from the anteroinferior LCL footprint to the posteroinferior PFL footprint, is less likely to blow out the lateral fibula than is a similar tunnel using the anatomic footprint centers.

Statement of problem The anterior mandible has conventionally been deemed as a safe zone for dental implants. However, with the evolution of cone beam computed tomography (CBCT), several anatomic challenges have been identified that, if violated, can lead to surgical complications, including life-threatening hemorrhage. Purpose The purpose of this observational clinical study was to obtain standardized average values for the location of the sublingual artery (SLA), submental artery (SMA), and mandibular incisive canal (MIC) and to determine whether differences exist between dentate and edentulous individuals. In addition, the prevalence of these anatomic landmarks on CBCT images was determined. An additional objective was to study the cross-sectional morphology of the anterior mandible. Material and methods CBCT images of 125 edentulous and 100 dentate patients were studied at the anterior mandible for the prevalence of SLA, SMA, and MIC. Measurements of these 3 structures were then made from the inferior cortical border of the mandible to the superior border of each structure to obtain average anatomic measurements. The cross-sectional shapes of anterior mandibles were then categorized, and the prevalence of each shape in this sample was calculated. Results The prevalence of SLA across all 225 CBCT images was 100% for edentulous patients and 98% for dentate patients. The SLA was located approximately 15 mm above the inferior border of the mandible. The prevalence of SMA was 94% for edentulous patients and 88% for dentate patients. The SMA was located approximately 5 mm above the inferior border of the mandible. The prevalence of MIC was 61% for edentulous patients and 59% for dentate patients. The MIC was located approximately 11 mm above the inferior border of the mandible in edentulous patients and approximately 14 mm above the inferior border of the mandible in dentate patients. Five distinct shapes were observed for the cross-sectional morphology of the anterior mandible: hourglass (1%), pear (53%), sickle (4%), ovoid (26%), and triangular (17%). The distance from the crest of the residual ridge to a minimum 6-mm width in the anterior mandible was approximately 4 mm. Conclusions The SLA and SMA vascular structures were consistently identified in the anterior mandible on CBCT images, both in dentate and edentulous patients, whereas the mandibular incisive canal was not consistently visualized. Average values from the inferior border of the mandible to the SLA, SMA, and MIC were computable. The cross-sectional morphology of the anterior mandible is diverse in dentate and edentulous mandibles, with pear shaped being the most common in both. These findings should be taken into consideration when dental implants are planned in the anterior mandible.

Objective To review the microsurgical anatomy of the donor arteries for extracranial-intracranial bypass, namely, the superficial temporal artery (STA), occipital artery (OA), and internal maxillary artery (IMA). Methods Seven cadaveric specimens were dissected to identify the relationships between each artery and its surrounding structures. Nineteen computed tomographic angiographic images of Japanese adult patients (38 sides) were analyzed to examine the course of each artery and to measure the diameters and distances from various anatomic landmarks to each artery. Results The courses of the STA, OA, and IMA, which must be exposed during revascularization procedures, were shown via cadaver dissection with special reference to the following relationships to surrounding structures: STA, soft tissue layers of the temporoparietal region and facial nerve; OA, suboccipital muscles; and IMA, mandibular nerve. In addition, we measured the diameter of the anastomotic site for each artery and its relationship with surrounding muscles. Conclusions A precise understanding of the anatomic characteristics of the donor arteries and their relationships with surrounding structures provides safe access to these arteries.

Background Traditionally, rectal cancer radiation therapy uses bony landmark fields to cover common lymphatic drainage sites, including the internal iliac, presacral, and perirectal lymph nodes. We aimed to investigate if bony landmark borders sufficiently cover the internal iliac nodes and to compare tumor volume and normal tissue avoidance using classic bony landmarks (c3DCRT), contoured elective clinical target volume (f3DCRT), and volumetric modulated arc therapy (VMAT) planning in locally advanced rectal cancer. Methods Computed tomography datasets of 11 patients with locally advanced rectal cancer who had completed treatment in the prone position on a bellyboard in c3DCRT technique. The elective clinical target volumes and organs at risk were contoured, and a f3DCRT VMAT plan generated for all patients. Planning target volume, gross tumor volume, and normal tissue dose limits were evaluated. Results The mean planning target volume 95% coverages were significantly lower for c3DCRT plans, and the lymph node coverage was better for f3DCRT. No differences were found in PTV coverages between f3DCRT and volumetric modulated arc therapy plans. No significant differences among all techniques were found for organs-at-risk constraints. The bladder dosage was higher in the VMAT plan. The c3DCRT technique missed coverage of the internal iliac lymph nodes and exposed smaller bowel, compared with the other methods. Discussion and Conclusion Tumor volume coverage was improved by f3DCRT planning, without significant differences in doses to critical structures compared with c3DCRT and was noninferior to VMAT planning. It is recommended that f3DCRT be used in routine clinical practice in radiotherapy treatments for locally advanced rectal cancer.

Summary Objective The purpose of the study was to evaluate the reliability of the most common landmarks and variables in digital lateral cephalometric radiographies in fixed and natural head positions. Materials and methods Twenty-one patients with anterior or distal displacement of the mandible treated in the Postgraduate Orthodontic Clinic of the Aristotle University of Thessaloniki had a digital lateral cephalometric radiography in fixed and in natural head position. The images where digitized. The main investigator and 6 examiners, digitized 61 landmarks and analysed 34 variables. We examined the intra-observer and inter-observer variability. Results There was a significant difference in X-axis in the distribution (hence the mean results) according to the reliability of the landmarks and in only 2 variables in digital lateral cephalograms between fixed and natural head position. Conclusions Cephalometric landmarks and variables showed reliability in digital lateral cephalometric radiography in fixed and natural head position. In lateral cephalograms taken in fixed head position an anterior inclination of the head was noticed compared to those in natural head position.

Three-dimensional (3D) preoperative planning and assisted surgery is increasingly popular in deformity surgery and arthroplasty. Reference ranges for 3D lower limb alignment are needed as a prerequisite for standardized analysis of alignment and preoperative planning in 3D, but are not yet established.On 60 3D bone models of the lower limbs based on computed tomography data, fifteen parameters per leg were assessed by standardized validated 3D analysis. Distribution parameters and differences between sexes were evaluated. Reference values were generated by adding/subtracting one standard deviation from the mean.Women had a significantly lower mean mechanical lateral distal femoral angle compared with men (86.4 ± 2.1° vs. 87.8 ± 2.0°; P .05) and significantly lower mean joint line convergence angle (-2.5 ± 1.4° vs. -1.3 ± 1.2; P .01), but higher mean hip knee ankle angle (178.9 ± 1.9° vs. 177.8 ± 2.3°; P .05) and mean femoral torsion (18.2 ± 9.5° vs. 13.2 ± 6.4°; P .05), resulting in a tendency towards valgus alignment and vice versa for men. Differences in mean medial proximal tibial angle were not significant. The mean mechanical axis deviation from the tibial knee joint center was 6.9 ± 7.3 mm medial and 1.4 ± 16.1 mm ventral without significant differences between sexes.We describe total and sex-related reference ranges for all alignment relevant axes and joint angles of the lower limb. There are sex-related differences in certain alignment parameters, which should be considered in analysis and surgical planning.

Central venous cannulation (CVC) is common and necessary in pediatric intensive care. However, this procedure is not without risks or complications. Although CVCs have classically been placed following anatomical landmarks, the use of ultrasound guidance has largely replaced the latter, given its better profile of efficacy and safety, demonstrated at least in adult populations.To compare the effectiveness and safety in the insertion of femoral central venous catheters guided by ultrasound (US) versus the anatomical method (LM) in critical care pediatric patients.100 patients were randomized: 50 were assigned to the US group and 49 to the LM group. In the LM group the traditional method consisted in palpating the femoral artery pulse as a; in the US group the CVC was inserted using a real time technique. Success at the first attempt, overall success in cannulation, number of attempts and arterial puncture were the variables studied in both groups.Success at the first attempt and overall success in cannulation were significantly higher in the US group versus the LM (US 42% vs. LM 18%, p 0.011, US 84% vs. LM 51% p0.001, respectively). The incidence of puncture of the femoral artery was lower in the US group (LM 12 vs. US 5, p 0.056) without achieving statistical significance.According to our results, the placement of central venous access via the femoral approach should be preferably performed under ultrasound guidance, however, further studies in larger populations are needed to confirm this findings.

Purpose To develop an accurate and reproducible method for establishment of a true en face view of the glenoid with a traumatic bone defect. Methods A total of 50 sets of computed tomography images of the glenoid were used for 3-dimensional reconstruction. Both a quantitative definition and a practical method were designed for creation of the true en face view of the glenoid with a traumatic bone defect. The accuracy and reliability of the quantitative definition and the practical method were evaluated by calculating the maximal projection area and the simulated bone defect size. Results The glenoid surface could be fit with a sphere with a radius of 26.11 ± 2.15 mm (P Conclusions This study provided a quantitative definition and a practical method for generation of the true en face view in the presence of a traumatic bone defect based on the best-fit sphere of the glenoid surface as well as the anatomic landmark of the supraglenoid and infraglenoid tubercles. This study may improve the reliability of the quantification of traumatic bone defects of the glenoid. Clinical Relevance The practical method for establishment of the true en face view of the glenoid would be useful in decision making for the treatment of traumatic anterior shoulder instability.

Background Surgical management of extensive skull base tumors, such as chordoma and chondrosarcoma, remains very challenging. The need for gross total removal to improve survival must be weighed against the risk of injury to neurovascular structures and the loss of stability at the craniovertebral junction. In cases of tumors that are already compromising craniovertebral junction stability, the occipital condyle can be exploited as a deep keyhole to reach the clivus, petrous apex, and sphenoid sinus. Methods We performed an anatomic study on 7 cadaveric specimens to describe the main landmarks and boundaries of the corridor. We also provide a clinical case to demonstrate the feasibility of the approach. Results In all specimens, using the space provided by the condyle, it was possible to drill the petrous bone up to the posterior wall of the sphenoid sinus following the direction of the inferior petrosal sinus. To successfully complete the approach, after the hypoglossal canal was exposed, endoscopic assistance was needed to overcome the narrowing of the visual field provided by the microscope. Conclusions In cases of invasive skull base tumor involving the craniovertebral junction and affecting its stability, the occipital condyle can be exploited as a deep keyhole to the homolateral and contralateral petrous apex, clivus, and sphenoid sinus.

Summary Background Defining three-dimensional (3D) normal craniofacial morphology in healthy children could provide craniofacial surgeons a reference point to assess disease, plan surgical reconstruction, and evaluate treatment outcome. The purposes of this study were to report normal craniofacial form and quantify craniofacial asymmetry of healthy children in Taiwan by implementing the 3D stereophotogrammetry technique. Methods Healthy Taiwanese elementary school children (n = 652) aged 6–12 years with no known craniofacial anomaly were recruited. After the 3dMD scanning procedure, 32 landmarks were manually placed on the 3D cranial images. Thin plate spline algorithm based on landmarks and closest point matching was applied to deform a symmetric 3D template into the scale of each scanned images. Skull asymmetry and facial asymmetry were calculated using 3dMD vultus and MATLAB. Average head shape models were also presented. Results Overall, the mean head transverse width, height, anteroposterior length, and circumferences were 163.02, 220.79, 179.07, and 526.55 mm, respectively. On average, the skull asymmetry and facial asymmetry were 2.47 ± 1.26 mm and 0.96 ± 0.53 mm, respectively, with no significant (all p > 0.05) differences found when comparing males and females. In the average head shape model, certain craniofacial areas on the right side were found to be more protruded than those on the left side. Conclusions This study shows that the baseline craniofacial form of the Taiwanese elementary school children is asymmetric with a tendency of more protrusion of the head on the right side.

Background The identification and precise removal of bony impingement lesions during arthroscopic debridement arthroplasty for elbow osteoarthritis is technically difficult. Surgical navigation systems, combined with preoperative 3-dimensional (3D) assessment of bony impingements, can provide real-time tracking of the surgical instruments and impingement lesions. This study aims to determine the registration accuracy of the navigation system for the humerus and ulna during elbow arthroscopy. Methods We tested the registration procedure using resin bone models of 3 actual patients with elbow osteoarthritis. We digitized bone surface points using navigation pointers under arthroscopy. We initially performed paired-point registration, digitizing 6 preset anatomical landmarks, and then refined the initial alignment with surface matching registration, digitizing 30 points. The registration accuracy for each trial was evaluated as the mean target registration error in each reference marker. Three observers repeated the registration procedure 5 times each with the 3 specimens (total, 45 trials). The median of the registration accuracy was evaluated in total (45 trials) as the accuracy of the registration procedure. The differences in the registration accuracy among the 3 observers (median of 15 trials) were also examined. Results The total registration accuracies were 0.96 mm for the humerus and 0.85 mm for the ulna. No significant differences were found in the registration accuracy for the humerus and ulna among the 3 observers. Conclusions This arthroscopic-assisted registration procedure is sufficiently feasible and accurate for application of the navigation system to arthroscopic debridement arthroplasty in clinical settings.

Background Restoration of anatomical relationship between talus and tibia is crucial for longevity of total ankle replacement (TAR). Weight-bearing (WB) radiographs are the standard for evaluating the sagittal balance alignment, but are prone to rotational misalignment and altered measurements. Metal artifact reduction sequence (MARS) MRI allows visualization of periprosthetic landmarks and alignment of the image plane to the true sagittal axis of the implant. The purpose of this study was to compare TAR sagittal balance measurements on MARS MRI and WB radiographs. Methods Twenty-three subjects with TAR [10 men/13 women, age 60 (41–73) years; 13 (3–24) months post-op] underwent MARS MRI and standard lateral WB radiographs. Standardized MARS MR images were aligned to the sagittal talar component axis. Three observers performed sagittal balance alignment measurements twice in an independent, random and blinded fashion. Lateral Talar Station (LTS), tibial axis-to-talus (T-T) ratio and normalized tibial axis-to-lateral-process (T-L) distance were measured. Concordance correlation coefficients (CCC) and intraclass correlation coefficients (ICC) were used for statistical analysis. In addition, mixed effects linear models were employed to assess overall concordance of the two image types. Results The intraobserver agreement was excellent for radiographic (CCC = 0.96) and MRI (CCC = 0.90–0.97) measurements. Interobserver agreements were good-to-excellent with overall slightly higher agreements for MRI (ICC = 0.78–0.94) than radiography (ICC = 0.78–0.90) measurements. The T-T ratios of radiographs and MRI showed a high degree of concordance, whereas LTS was significantly lower on MRI when compared with radiographs, and T-L distance showed notable disagreement between the two imaging types. Conclusion Sagittal balance measurements performed on standardized weight-bearing radiographs and standardized MARS MRI demonstrate substantial correlation and similarity. Given its high intra and interobserver agreement, MARS MRI may be helpful for the evaluation of TAR sagittal balance. Level of evidence: Level II - Prospective Comparative Study.

Purpose Lymphedema after regional nodal irradiation is a severe complication that could be minimized without significantly compromising nodal coverage if the anatomic region(s) associated with lymphedema were better defined. This study sought to correlate dose-volume relationships within subregions of the axilla with lymphedema outcomes to generate treatment planning guidelines for reducing lymphedema risk. Methods and Materials Women with stage II-III breast cancer who underwent breast surgery with axillary assessment and regional nodal irradiation were identified. Nodal targets were prospectively contoured per Radiation Therapy Oncology Group guidelines for field design. The axilla was divided into 8 distinct subregions that were retrospectively contoured. Lymphedema outcomes were assessed by arm circumferences. Multivariate Cox proportional hazards regression assessed patient, surgical, and dosimetric predictors of lymphedema outcomes. Results Treatment planning computed tomography scans for 265 women treated between 2013 and 2017 were identified. Median post–radiation therapy follow-up was 3 years (interquartile range [IQR], 1.9-3.6). Dose to the axillary-lateral thoracic vessel juncture (ALTJ; superior to level I) was most associated with lymphedema risk (maximally selected rank statistic = 6.3, P Conclusions Anatomic studies suggest the ALTJ region is typically traversed by arm lymphatics and appears to be an organ at risk in breast radiation therapy. Ideally, avoidance of the ALTJ may be feasible while simultaneously encompassing breast-draining nodal basins. Confirmation of this finding in future prospective studies is needed.

Background The Eustachian tube and sphenoid spine have been previously described as landmarks for endonasal surgical identification of the most distal segment of the parapharyngeal internal carotid artery (PhICA). However, the intervening space between the sphenoid spine and PhICA allows for error during exposure of the artery. In the present study, we have characterized endoscopic endonasal transmasticator exposure of the PhICA using the sphenoid spine, vaginal process of the tympanic bone, and the “tympanic crest” as useful anatomical landmarks. Methods Endonasal dissection was performed in 13 embalmed latex-injected cadaveric specimens. Two open lateral dissections and osteologic analysis of 10 dry skulls were also performed. Results A novel and palpable bony landmark, the inferomedial edge of the tympanic bone, referred to as the tympanic crest, was identified, leading from the sphenoid spine to the lateral carotid canal. Additionally, the vaginal process of the tympanic bone, viewed endoscopically, was a guide to the PhICA. The sphenoid spine was bifurcate in 20% of the skulls, with an average length of 5.98 mm (range, 3.9–8.2 mm), width of 5.81 mm (range, 3.0–10.6 mm), and distance to the carotid canal of 4.48 mm (range, 2.5–6.1 mm). Conclusion The sphenoid spine and pericarotid space has variable anatomy. Using an endoscopic transmasticator approach to the infratemporal fossa, we found that the closest landmarks leading to the PhICA were the tympanic crest, sphenoid spine, and vaginal process of the tympanic bone.

Background Navigated transcranial magnetic stimulation (nTMS) provides a reliable identification of “eloquent” cortical brain areas. Moreover, it can be used for diffusion tensor imaging fiber tracking of eloquent subcortical tracts. We describe the use of nTMS-based cortical mapping and diffusion tensor imaging fiber tracking for defining the “eloquence” of areas surrounding brain arteriovenous malformations (BAVMs), aiming to improve patient stratification and treatment. Methods We collected data of BAVMs suspected to be in eloquent areas treated between 2017 and 2019, and submitted to nTMS-based reconstruction of motor, language, and visual pathways for the definition of the eloquence of the surrounding brain areas. We describe the nTMS-based approach and analyze its impact on patient stratification and allocation to treatment in comparison with the standard assessment of eloquence based on anatomical landmarks. Results Ten patients were included in the study. Preliminarily, 9 BAVMs were suspected to be located in an eloquent area. After nTMS-based mapping, only 5 BAVMs were confirmed to be close to eloquent structures, thus leading to a change of the score for eloquence and of the final BAVMs grading in 60% of patients. Treatment was customized according to nTMS information, and no cases of neurological worsening were observed. Radiological obliteration was complete in 7 cases microsurgically treated, and accounted for about 70% in the remaining 3 patients 1 year after radiosurgical treatment. Conclusions The nTMS-based information allows an accurate stratification and allocation of patients with BAVMs to the most effective treatment according to a modern, customized, neurophysiological identification of the adjacent eloquent brain networks.

Purpose To report an iliac venous stent landing technique using only fluoroscopy in patients with May-Thurner syndrome (MTS). Material and Methods Sixty-five patients (69% female) who had self-expanding nitinol stents deployed for symptomatic MTS were retrospectively analyzed. Mean age was 50 years (range 18–80). The cephalic stent right lower corner was deployed to the right of the lumbar vertebra spinous process (SP), but not as far to the right as the right pedicle lateral border. Mode stent diameter and length were 14 mm (range 12–18) and 120 cm (range 60–180), determined by venography, respectively. The anatomical positions of the right common iliac artery, inferior vena cava (IVC), and stent were assessed relative to these bony landmarks on computed tomography venography. Results Position of the proximal right common iliac artery right lateral border lay a mean distance of 12 mm (±8 to the right of the SP and 13 mm (±7) left of the right pedicle lateral border. Mean position of the IVC right lateral wall lay 1 mm (±6) to the right of the right pedicle lateral border. Mean position of the cephalic stent right lower corner was 6 mm (±6) to the left of the right pedicle lateral border and 19 mm (±7) to the right of the SP. The mean space left between the cephalic stent right lower corner and the IVC right lateral wall was 5 mm (±5). Primary patency rate at 1 year was 88%. Conclusions Important vascular structures lie in predictable locations relative to bony landmarks, facilitating accurate venous stent placement using fluoroscopy only.

The goal of this work was to develop a method for accurate and robust automatic segmentation of the prostate clinical target volume in transrectal ultrasound (TRUS) images for brachytherapy. These images can be difficult to segment because of weak or insufficient landmarks or strong artifacts. We devise a method, based on convolutional neural networks (CNNs), that produces accurate segmentations on easy and difficult images alike. We propose two strategies to achieve improved segmentation accuracy on difficult images. First, for CNN training we adopt an adaptive sampling strategy, whereby the training process is encouraged to pay more attention to images that are difficult to segment. Secondly, we train a CNN ensemble and use the disagreement among this ensemble to identify uncertain segmentations and to estimate a segmentation uncertainty map. We improve uncertain segmentations by utilizing the prior shape information in the form of a statistical shape model. Our method achieves Hausdorff distance of 2.7 ± 2.3 mm and Dice score of 93.9 ± 3.5%. Comparisons with several competing methods show that our method achieves significantly better results and reduces the likelihood of committing large segmentation errors. Furthermore, our experiments show that our approach to estimating segmentation uncertainty is better than or on par with recent methods for estimation of prediction uncertainty in deep learning models. Our study demonstrates that estimation of model uncertainty and use of prior shape information can significantly improve the performance of CNN-based medical image segmentation methods, especially on difficult images.

Study Design Descriptive in situ cadaveric study. Introduction Performing accurately directed examination and treatment to the wrist requires clinicians to orient to carpal bone structures. Purpose of the Study To examine the anatomical relationships that exist within the wrist–hand complex and identify the accuracy of surface anatomy mapping strategies for localizing anatomical landmarks using a palmar approach. Methods Twenty-three embalmed cadavers were dissected using standardized procedures. Metal markers were placed in the most prominent palmar landmark of key carpal structures. Relationships between the most prominent palpation landmarks and the carpal bones of interest were visualized using fluoroscopy. Results The most successful methods of palmar capitate localization included the midpoint of a line from trapezium tubercle to pisiform; the midpoint of a line from scaphoid tubercle to hamate hook; or the intersection (cross) of these 2 diagonal lines, with successful capitate identification 100% (23/23) of the time. The most successful method for locating the lunate included the midpoint of a line from the radial styloid process to the ulnar styloid process, which identified the lunate in 100% (23/23) of cases. Discussion The results of this cadaveric anatomical relationship study support the use of the midpoint of a line from pisiform to trapezium tubercle, the midpoint of a line from scaphoid tubercle to hamate hook, or a combination (cross) of these lines to locate the capitate from a palmar approach. In addition, the anatomical relationships examined in this study support the use of the midpoint of a line from the radial styloid process to ulnar styloid process to locate the lunate from a palmar approach. Knowledge of these anatomical relationships may improve the clinician’s confidence in locating the capitate and lunate during intercarpal examination, special testing, and treatment. Conclusion Results of this study provide information of the anatomical relationships of the carpal bones from a palmar approach, giving clinicians a foundation for proper orientation to the carpal bones during clinical examination and intervention. Further research is needed to evaluate the reliability and accuracy of these methods for surface palpation on live patients.

We present hierarchical spherical deformation for a group-wise shape correspondence to address template selection bias and to minimize registration distortion. In this work, we aim at a continuous and smooth deformation field to guide accurate cortical surface registration. In conventional spherical registration methods, a global rigid alignment and local deformation are independently performed. Motivated by the composition of precession and intrinsic rotation, we simultaneously optimize global rigid rotation and non-rigid local deformation by utilizing spherical harmonics interpolation of local composite rotations in a single framework. To this end, we indirectly encode local displacements by such local composite rotations as functions of spherical locations. Furthermore, we introduce an additional regularization term to the spherical deformation, which maximizes its rigidity while reducing registration distortion. To improve surface registration performance, we employ the second order approximation of the energy function that enables fast convergence of the optimization. In the experiments, we validate our method on healthy normal subjects with manual cortical surface parcellation in registration accuracy and distortion. We show an improved shape correspondence with high accuracy in cortical surface parcellation and significantly low registration distortion in surface area and edge length. In addition to validation, we discuss parameter tuning, optimization, and implementation design with potential acceleration.

The determination of anatomic landmarks on the pelvis is an important procedure in orthopaedics, computational biomechanics and morphometrics. This study aimed to develop a robust method for determining the anatomic landmarks on the pelvis and demonstrate the application of the method in assessing the native acetabular orientation and developing multiscale computational modelling for hip biomechanics. Two Matlab algorithms, named "Pelvisor" and "Acetabulor", were developed to determine four anatomic landmarks on the pelvis and assess the acetabular orientation in the natural hip. The algorithms were then applied to: (1) assess the native acetabular orientations for a cohort of subjects; (2) develop a multiscale computational modelling to investigate the biomechanical behaviour of the biphasic cartilage in the natural hip joint. Results showed that the present method can accurately determine the key anatomic landmarks on the pelvis and assess the acetabular orientation in the natural hip joint. Significant differences in acetabular inclination and anteversion between males and females were identified, with larger orientations in females. The interstitial fluid pressure in the cartilage supported over 90% of loading during gait, and the stresses and strains within the solid matrix of the cartilage were as low as 1.8 MPa and 0.12, respectively.

Introduction Intravascular ultrasound (IVUS) is a useful adjunct to guide percutaneous coronary intervention (PCI). Correlating IVUS images with angiographic findings can be challenging. We evaluated the utility of a novel co-registration system for IVUS and coronary angiography. Methods and results A 3-D virtual catheter trajectory was constructed from separate angiographic imaging runs using bespoke software. Intravascular ultrasound images were obtained using a commercially available mechanical rotational transducer with motorized pullback. Co-registration of ultrasound and angiographic images was then performed retrospectively based on the length of pullback, the 3-D trajectory and the start position of the catheter. Validation was performed in a spherical phantom model and in vivo in the coronary circulation of patients undergoing coronary angiography and intravascular imaging for clinical purposes. 111 paired angiographic and IVUS runs were performed in 3 phantom models. The differences between the reference length and the length measured on the 3D reconstructed path was −0.01 ± 0.40 mm. Intra-observer variability was 0.4%. We enrolled 25 patients in 3 European hospitals and performed 35 co-registration attempts with an 86% success rate. 71 landmarks were selected by the first operator, 68 by the second. Differences between angiographic and IVUS landmarks were −0.22 ± 0.72 mm and 0.05 ± 1.01 mm, respectively. Inter-observer variability was 0.23 ± 0.63 mm. Conclusion We present a novel method for the co-registration of IVUS and coronary angiographic images. This system performed well in a phantom model and using images obtained from the human coronary circulation. Classifications Innovation, intravascular ultrasound, other technique

This study aims to investigate the feasibility of pig arytenoid cartilage as an animal model for simulating arytenoidectomy under microlaryngoscope by comparing the similarities and differences between pig arytenoid cartilage and human arytenoid cartilage.This is a methodological study on the excised pig arytenoid cartilage and human arytenoid cartilage.Five excised human adult cadaver larynges and five adult excised porcine larynges were dissected and all the soft tissue and mucous membrane attached to the arytenoid and cricoarytenoid joint were removed. The anatomical structure and morphology of the arytenoid cartilage were observed and measured with a vernier caliper. Measurements included cricoarytenoid articular facet major and minor diameter, cricoarytenoid articular facet center distance, cricoarytenoid facet major and minor diameter, length of vocal process and muscular process, and distance between tip of vocal process, muscular process, and junction/apex of arytenoid cartilage. Data were then compared across these major anatomic markers using student t test.The gross anatomy of the pig arytenoid cartilage was similar to the human. However, the size of the pig larynx arytenoid cartilage was obviously larger in total, and there was statistical significance for almost all measurements (P 0.05), except the mean value of cricoarytenoid articular facet center distance, the cricoarytenoid facet minor diameter, and the length of vocal process of pig and human, without statistically significant difference (P 0.05). Moreover, the biggest differences between the pig arytenoid cartilage and the human arytenoid cartilage were that the pig arytenoid cartilage apex had the angle winding structure toward the back, and that the posterior part of the bilateral arytenoid cartilages was partially connected. Whereas after the angle winding was removed from the junction, pig arytenoid cartilage and human arytenoid cartilage were shaped both like a triangular pyramid.The data of this metric comparative study indicate that pig arytenoid, after resecting the angle winding structure and incising the interarytenoid cartilage, is similar to the human's. Therefore, pig larynx is an appropriate experimental model for endoscopic arytenoidectomy. In addition, regarding the pig laryngeal angle winding structure, we still require further basic and clinical research to clarify its physiological function and significance.

Background Use of ultrasound-guidance for central venous access in adults is the standard of care. There is, however, less clarity in the role of routine ultrasound use in obtaining venous access in children. We sought to evaluate safety and efficiency of the placement of central lines utilizing an ultrasound-guided approach compared to the traditional, landmark approach in pediatric patients. Study design A single-institution retrospective chart review, using CPT codes, was performed for all tunneled central venous catheters in children between 2005 and 2017 by the same pediatric surgery group. During the study period, a practice change occurred from exclusively landmark-based line placement to ultrasound-guided line placement. Groups were divided into three phases: a traditional/landmark era (Phase 1), transitional period (Phase 2), and the ultrasound era (Phase 3). The primary outcomes analyzed were postoperative chest tube insertions and operative time. Results A total of 2010 tunneled central lines were included for analysis: Phase 1 (N = 930), Phase 2 (N = 313) and Phase 3 (N = 767). Venous access for chemotherapy was the most common indication (29%). Phase 1 had a chest tube placement rate of 9.7/1000 procedures, while Phase 2 had a rate of 6.4/1000 procedures, and Phase 3 had no chest tube insertions (p = 0.009). Phase 1 had longer OR times compared to Phase 2 (57 vs. 49, p = 0.0026) and Phase 3 (57 vs. 46 min, p Conclusions This study represents the largest analysis of ultrasound-guided access for children. A complete practice transition to the ultrasound-guided approach was feasible within a two-year period. The ultrasound-guided approach had a shorter operative time and less chest tube insertions than the traditional, landmark technique in children. Level III evidence.