Individual Patient Anatomy Research Articles

Accuracy of Preoperative Cochlear Duct Length Estimation and Angular Insertion Depth Prediction.

In cochlear implantation with flexible lateral wall electrodes, a cochlear coverage of 70% to 80% is assumed to yield an optimal speech perception. Therefore, fitting the cochlear implant (CI) to the patient's individual anatomy has gained importance in recent years. For these reasons, the optimal angular insertion depth (AID) has to be calculated before cochlear implantation. One CI manufacturer offers a software that allows to visualize the AID of different electrode arrays. Here, it is hypothesized that these preoperative AID models overestimate the postoperatively measured insertion angle. This study aims to investigate the agreement between preoperatively estimated and postoperatively measured AID. Retrospective cross-sectional study. Single-center tertiary referral center. Patients undergoing cochlear implantation. Preoperative and postoperative high-resolution computed tomography (HRCT). The cochlear duct length was estimated by determining cochlear parameters ( A value and B value), and the AID for the chosen electrode was (i) estimated by elliptic circular approximation by the software and (ii) measured manually postoperatively by detecting the electrode contacts after insertion. A total of 80 HRCT imaging data sets from 69 patients were analyzed. The mean preoperative AID estimation was 662.0° (standard deviation [SD], 61.5°), and the mean postoperatively measured AID was 583.9° (SD, 73.6°). In all cases (100%), preoperative AID estimation significantly overestimated the postoperative determined insertion angle (mean difference, 38.1°). A correcting factor of 5% on preoperative AID estimation dissolves these differences. The use of an electrode visualization tool may lead to shorter electrode array choices because of an overestimation of the insertion angle. Applying a correction factor of 0.95 on preoperative AID estimation is recommended.

Assessing the Variability of the Twelfth Rib as a Landmark for Percutaneous Nephrolithotomy Using Computed Tomography.

The variability in length of the twelfth rib is mentioned in the literature but has never been formally studied. The highly variable rib length provides a challenge for urologists seeking a consistent landmark for Percutaneous Nephrolithotomy (PCNL). We set out to determine whether the twelfth rib is safe to use as a consistent landmark for surgery. Single centre, cross-sectional retrospective observational study and analysis of CT scans of 100 adults who had imaging between 23rd March and 12th April 2020. The distance from the mid-sagittal line to the twelfth rib tip in the axial plane was measured as was the distance from the twelfth rib tip to the kidney, spleen and liver. Length from the mid-sagittal line to the right twelfth rib tip varied from 46 (percentile 95% CI 40 to 57) to 136mm (percentile 95% CI 133 to 138). On the left, the distances varied from 55 (percentile 95% CI 50 to 64) to 134mm (percentile 95% CI 131 to 135). Twenty-three percent of people had an organ lying between the tip of the twelfth rib and the kidney on the right and 11% on the left. The twelfth rib is highly variable in length. Similar variability was recorded in the distance from the tip to intra-abdominal organs. Due to the frequency of organs lying between the tip of the rib and the kidney it should not be used as a landmark for accessing the kidney without prior knowledge of an individual patient's anatomy as seen on imaging.

Modeling the effect of patient size on cerebral perfusion during veno-arterial extracorporeal membrane oxygenation.

A well-known complication of veno-arterial extracorporeal membrane oxygenation (VA ECMO) is differential hypoxia, in which poorly-oxygenated blood ejected from the left ventricle mixes with and displaces well-oxygenated blood from the circuit, thereby causing cerebral hypoxia and ischemia. We sought to characterize the impact of patient size and anatomy on cerebral perfusion under a range of different VA ECMO flow conditions. We use one-dimensional (1D) flow simulations to investigate mixing zone location and cerebral perfusion across 10 different levels of VA ECMO support in eight semi-idealized patient geometries, for a total of 80 scenarios. Measured outcomes included mixing zone location and cerebral blood flow (CBF). Depending on patient anatomy, we found that a VA ECMO support ranging between 67-97% of a patient's ideal cardiac output was needed to perfuse the brain. In some cases, VA ECMO flows exceeding 90% of the patient's ideal cardiac output are needed for adequate cerebral perfusion. Individual patient anatomy markedly affects mixing zone location and cerebral perfusion in VA ECMO. Future fluid simulations of VA ECMO physiology should incorporate varied patient sizes and geometries in order to best provide insights toward reducing neurologic injury and improved outcomes in this patient population.

Injection technique of the upper face with onabotulinumtoxinA in chronic migraine.

The objective is to review the technique of onabotulinumtoxinA injection treatment in the glabellar and frontal regions using the PREEMPT (Phase III REsearch Evaluating Migraine Prophylaxis Therapy) paradigm, with review of the aesthetic issues related to the procedure. OnabotulinumtoxinA is an effective medication for the prevention of chronic migraine. The PREEMPT injection paradigm has been validated in randomized clinical trials and real-world settings. This treatment includes injections in the forehead and glabella area. In addition, for aesthetic uses, glabella onabotulinumtoxinA injections are done in similar muscles specifically the procerus, corrugator supercilii, and frontalis muscles. Often patients who have been injected with onabotulinumtoxinA for chronic migraine have concerns about their appearance and will ask if they can see an aesthetic injector to improve this. This is a difficult issue as onabotulinumtoxinA should be injected with an interval of 10-12 weeks to avoid development of antibodies against onabotulinumtoxinA, so all injections (migraine and aesthetic) should ideally be done close together; however, if an aesthetic injection is done on the same day as a PREEMPT injection, the effect of the PREEMPT injection will not yet be visible as it takes time for onabotulinumtoxinA effects to be seen. Thus, there is a risk of a potential overdose in a particular area if aesthetic injections are done without input from the PREEMPT injector. This is a narrative review supported by photographic documentation showing the technique of onabotulinumtoxinA injection of the upper face, considering anatomical differences between patients, and combining the needs in neurology and aesthetic medicine fields. Practitioners treating chronic migraine often modify some of the principles of the PREEMPT paradigm. Many practitioners are unsure about injections in the glabellar and frontal areas. The authors present a technique for using the PREEMPT protocol and adapting this to the individual patient's anatomy to prevent an unsightly appearance or ptosis. In addition, sites are provided where an aesthetic injector could inject to improve the patient's appearance without overlapping with the PREEMPT injection sites. Adherence to the PREEMPT injection protocol provides an evidence-based approach to achieving clinical benefit for patients with chronic migraine. Aesthetic elements of the treatment of the glabella and forehead require additional attention. The authors provide practical considerations and recommendations regarding this.

Patient anatomy-specific trade-offs between sub-clinical disease coverage and normal tissue dose reduction in head-and-neck cancer

PurposeRisk of subclinical disease decreases with increasing distance from the GTV in head- and-neck squamous cell carcinoma (HNSCC). Depending on individual patient anatomy, OAR sparing could be improved by reducing target coverage in regions with low risk of subclinical spread. Using automated multi-criteria optimization, we investigate patient-specific optimal trade-offs between target periphery coverage and OAR sparing. MethodsVMAT plans for 39 HNSCC patients were retrospectively created following our clinical three-target-level protocol: high-risk (PTV1), intermediate-risk (PTV2, 5 mm expansion from PTV1), and elective (PTV3). A baseline plan fulfilling clinical constraints (D 99 % ≥95 % for all PTVs) was compared to three plans with reduced PTV2 coverage (goals: PTV2 D 99 % ≥90 % or 85 %, or no PTV2) at the outer edge of PTV2. Plans were compared on PTV D 99 %, OAR D mean, and NTCP (xerostomia/dysphagia). ResultsTrade-offs between PTV2 coverage and OAR doses varied considerably between patients. For plans with PTV2 D 99 % -goal 90 %, median PTV2 D 99 % was 91.5 % resulting in xerostomia (≥grade 4) and dysphagia (≥grade 2) NTCP decrease of median [maximum] 1.9 % [5.3 %] and 1.1 % [4.1 %], respectively, compared to nominal PTV2 D 99 % -goal 95 %. For PTV2 D 99 % -goal 85 % median PTV D 99 % was 87 % with NTCP improvements of 4.6 % [9.9 %] and 1.5 % [5.4 %]. For no-margin plans, PTV2 D 99 % decreased to 83.3 % with NTCP reductions of 5.1 % [10.2 %] and 1.4 % [6.1 %]. ConclusionClinically relevant, patient-specific reductions in OARs and NTCP were observed at limited cost in target under-coverage at the outermost PTV edge. Given the observed inter-patient variations, individual evaluation is warranted to determine whether trade- offs would benefit a specific patient.

Technical note: Flat panel proton radiography with a patient specific imaging field for accurate WEPL assessment.

Proton radiography (PR) uses highly energetic proton beams to create images where energy loss is the main contrast mechanism. Water-equivalent path length (WEPL) measurements using flat panel PR (FP-PR) have potential for in vivo range verification. However, an accurate WEPL measurement via FP-PR requires irradiation with multiple energy layers, imposing high imaging doses. A FP-PR method is proposed for accurate WEPL determination based on a patient-specific imaging field with a reduced number of energies (n) to minimize imaging dose. Patient-specific FP-PRs were simulated and measured for a head and neck (HN) phantom. An energy selection algorithm estimated spot-wise the lowest energy required to cross the anatomy (Emin) using a water-equivalent thickness map. Starting from Emin, n was restricted to certain values (n=26, 24, 22, …, 2 for simulations, n=10 for measurements), resulting in patient-specific FP-PRs. A reference FP-PR with a complete set of energies was compared against patient-specific FP-PRs covering the whole anatomy via mean absolute WEPL differences (MAD), to evaluate the impact of the developed algorithm. WEPL accuracy of patient-specific FP-PRs was assessed using mean relative WEPL errors (MRE) with respect to measured multi-layer ionization chamber PRs (MLIC-PR) in the base of skull, brain, and neck regions. MADs ranged from 2.1mm (n=26) to 21.0mm (n=2) for simulated FP-PRs, and 7.2mm for measured FP-PRs (n=10). WEPL differences below 1mm were observed across the whole anatomy, except at the phantom surfaces. Measured patient-specific FP-PRs showed good agreement against MLIC-PRs, with MREs of 1.3±2.0%, -0.1±1.0%, and -0.1±0.4% in the three regions of the phantom. A method to obtain accurate WEPL measurements using FP-PR with a reduced number of energies selected for the individual patient anatomy was established in silico and validated experimentally. Patient-specific FP-PRs could provide means of in vivo range verification.

Right ventricular cardiac resynchronization therapy in patients with right ventricular conduction delay and heart failure

Right ventricular cardiac resynchronization therapy in patients with right ventricular conduction delay and heart failure

Equation predicting tibial-tuberosity to trochlear-groove distance following supratubercle osteotomy: Radiographic proof of concept

BackgroundSupratubercle tibial rotational osteotomies are useful in patellar stabilizing procedures with high tibial-tuberosity to trochlear-groove distance caused by excessive external tibial torsion. An investigation determined one degree of internal tibial rotation results in 0.68 mm reduction of tibial-tuberosity to trochlear-groove distance, but did not account for anatomical variability. MethodsThis is a radiographic proof of concept for equation validation. We compared two different derived equations, a complex four-variable and simplified two-variable equation, to the literature relationship and true measured value from CT imaging. Bilateral pre-operative CTs of 37 patients, evaluated for malalignment, were reviewed retrospectively. We virtually simulated derotations of five, ten and fifteen degrees, and compared the reduction in tibial-tuberosity to trochlear-groove distance measured radiologically from CTs to the one predicted by our equation. FindingsThe difference between the true change in tibial-tuberosity to trochlear-groove distance and that obtained using our four-variable was statistically insignificant for all derotation angles (p > 0.05), and the two-variable equation it was statistically insignificant for five and fifteen degrees of derotation (p > 0.05). Conversely, the true values were statistically different from those found using the published relationship (p < 0.05 for all). InterpretationThis new equation accounts for individual patient anatomy, for a more accurate relationship between internal rotation of the distal segment of the tibia and the subsequent decrease in the tibial-tuberosity to trochlear-groove distance. The change was overestimated using the linear relationship, which may result in under correction. Future studies will assess true post-operative distance change following osteotomy.

Trunnions and Modularity in Total Hip Arthroplasty: A Historical Review With Current Clinical Implications.

Trunnion in total hip arthroplasty refers to the interface between the neck of a femoral stem and the femoral head. Clinical complications arising from damage to this junction, whether it be due to mechanical wear, corrosion, or a combination, are referred to as mechanically assisted crevice corrosion (MACC), also commonly known as trunnionosis. With the use of modular hip prostheses, which help customize offset and leg length to an individual patient's anatomy, the incidence of MACC and revision due to MACC has increased in recent years. Although the cause of MACC is multifactorial, with patient factors and technique factors contributing to this condition, taper design and geometry, metallurgical properties of implants, and size mismatch of the bearing couple are some of the implant factors that have also been implicated in this clinical phenomenon. Understanding the history of taper design and geometry, the track record of older implants, and the rationale behind the development of current prostheses can help surgeons choose the right implants for their patients and accurately assess the pros and cons of new implants being introduced to the market each year.

Transradial Versus Transfemoral Intraoperative Cerebral Angiography for Open Cerebrovascular Surgery: Effectiveness, Safety, and Learning Curve.

Intraoperative cerebral angiography (IOA) is a valuable adjunct in open and hybrid cerebrovascular surgery. Commonly, transfemoral access (TFA) is used. Lately, transradial access (TRA) has gained popularity for neurointervention. However, the TRA has not yet been compared with the TFA for IOA. To compare the effectiveness and safety of the TRA and TFA for IOA. In addition, the learning curve for implementing the TRA for IOA was evaluated. Between July 2020 and 2022, 92/1787 diagnostic cerebral angiographies met inclusion criteria for IOA. Sheath run time to primary target vessel run time (STT), amount of contrast dye (CD), fluoroscopy time (FT), and dose-area products (DAPs) were compared between TRA and TFA, different aortic arch types, and both study years. One case required transitioning from TRA to TFA (1/26, 3.8%) because of a minute proximal radial vasculature. The STT, CD, FT, and DAP were similar for the TRA (n = 25) and the TFA groups (n = 67) (p = ns). One groin hematoma (1.5%) was observed in the TFA group. No other complications or any change in modified Rankin Scale were observed. Aortic arch type II/III was associated with longer STT ( P = .032) but not CD, FT, or DAP. There was a nonsignificant decline of STTs among the TRA cases ( P = .104) but stable STTs among TFA cases ( P = .775). The TRA and TFA represent equally effective and safe routes for IOA. In addition, expertise with the TRA can rapidly be gained and facilitates tailoring the access for IOA to patient's individual anatomy and surgeon's needs.

Innovative training modality for sacral neuromodulation (SNM): Patient-specific computerized tomography (CT) reconstructed 3D-printed training system: ICS School of Modern Technology novel training modality.

Sacral neuromodulation (SNM) is an effective treatment of urinary and bowel dysfunction, including secondary to neurological disorders. The learning curve for the optimal electrode placement for SNM is steep, expensive, and limited by patient factors such as obesity and previous injuries. We aim to create a patient specific 3-dimensional (3D) model for successful SNM training. A total of 26 urology residents who had different level of knowledge and experience were enrolled to the 3D SNM training program. The creation of 3D sacrum model has been started with evaluation of real patient computerized tomography images and creation of Digital Imaging and Communications in Medicinefiles. The segmented anatomic structures from the files then edited and stereolithographicfiles were generated for 3D-model prints via Mimics© software. The 3D-printed models were used for training and evaluation of participants during the SNM intervention was performed. The evaluation of 3D SNM model training was led by one mentor who is expert on SNM. On the preprinted 3D sacrum model all 26 participants were requested to perform the essential steps to complete a SNM procedure and individual procedure time was recorded. The mean and median scores were 18.8 and 19, respectively according to Likert scores (min 11 max 28). SNM is increasing in popularity as a treatment option with physicians and patients with refractory symptoms. Few experienced specialists exist, and more effective training methods are needed to tackle the increasing demand, and individual patient anatomy.

Abdominal Aortic Aneurysm: Can the Anaconda™ Custom-Made Device Deliver? An International Perspective.

IntroductionSince the introduction of endovascular aortic repair (EVAR), it has demonstrated excellent clinical outcomes and has replaced open surgical repair (OSR) in the treatment of abdominal aortic aneurysms (AAA). AAA is a life-threatening abnormal dilation of the abdominal aorta to 1.5 times its normal diameter. Several commercial EVAR devices exist on the global market, with the Terumo Aortic Fenestrated Anaconda™ graft showing superiority. In this study, we sought to provide an international perspective using multicenter-multinational data on the Anaconda™ device characteristics, design, and delivery, and discuss relevant literature.Materials and MethodsThis study represents a cross-sectional international analysis of custom-made fenestrated Anaconda™ device. Ethical and legal approval for data collection was obtained from each of the local authorities. For the statistical analysis, SPSS 28 for Windows and R were utilized. Pearson’s chi-square analysis was used to assess differences in cumulative distribution frequencies between select variables. Statistical significance for all two-tailed tests was set at p < 0.05.ResultsA total of 5,030 Anaconda™ devices were implanted during the 9-year study period in 27 countries spanning 6 continents. The predominant device category was bifurcate (83.6%), whereas the most common proximal ring stent configuration being standard (64.5%). All devices were delivered within 8 weeks of diagnosis, with most being implanted within 6–8 weeks (55.4%). The Anaconda™ was indicated in the 3,891 (77.4%) patients due to competitor rejection/inability to treat unsuitable/complex aortic anatomy. In the remaining 1,139 (22.6%) patients, it was utilized based on surgeon preference. Almost all devices (95%) were delivered along with a prototype. Of the total 5,030 Anaconda™ devices, 438 (8.7%) used 0–1 fenestrations, 2,349 (46.7%) used 2–3, while 2,243 (44.6%) utilized 4, 5, or 6 fenestrations.DiscussionThe Terumo Aortic Fenestrated Anaconda™ device features a highly unique and innovative design that enables it to treat highly complex aortic anatomy while achieving excellent results. The Anaconda™’s custom-made approach allows it to be tailored to individual patient anatomy, in addition to the device prototype provided by Terumo Aortic optimize clinical outcomes. Finally, the fenestrated Anaconda™ is a highly versatile device offering a wide range of device categories, configurations, and sizes.

Revascularization techniques in surgical treatment of large and giant anterior cerebral artery aneurysms: literature review

Despite common use of revascularization for aneurysms of other locations, the role of bypass has been ignored for long time. In this study we describe actual status of revascularization in surgical treatment of ACA aneurysms based on an analysis of current literature. Search of literature was performed in data bases PubMed and Web of Science. Treatment of 80 patients in 24 articles was evaluated. In situ A3‑A3 bypass and extra — intracranial bypass with the superficial temporal artery are the most used techniques. The contralateral superficial temporal artery is the most convenient interposition graft for bypasses performed in patients with ACA aneurysms. There are no significant differences between extra-intracranial and intra-intracranial bypasses in terms of bypass patency and ischemic complications. The choice between different bypass techniques is based on an individual patient anatomy and surgeon preference.

P.118 Radial to femoral “through and through” access for high grade ostial subclavian and innominate artery stenoses: a novel technique

Background: Endovascular approaches are typically preferred to open surgical techniques for symptomatic subclavian/innominate artery stenosis. Due to individual patient anatomy, endovascular treatment from a conventional femoral arterial approach can be technically challenging. Our alternative technique using a combined radial to femoral artery approach can facilitate an otherwise challenging revascularization procedure. Methods: Retrospective analysis between November 2017 to March 2021 yielded five procedures (in four patients) using a combined radial to femoral “through and through” access and stenting technique. Results: All patients presented with hypoperfusion symptoms, either to their extremities, brain, or both. Technical success was achieved in 100% of the five vessels treated in four patients with symptomatic subclavian/innominate artery stenosis using this approach. One of the patients developed a recurrent stenosis after 40 months, requiring a repeat procedure. Three patients received treatment to the left subclavian artery and one to the innominate artery. All of the patients experienced marked symptomatic improvement without significant complications. Conclusions: A combined radial to femoral “through and through” access technique is a simple and safe method to achieve successful recanalization of high grade symptomatic ostial stenoses of the subclavian and innominate arteries.

Electric field aspects in hypoglossal nerve stimulation for obstructive sleep apnea: A bilateral electrophysiological evaluation of unilateral electrode configuration changes.

Hypoglossal nerve stimulation is an established treatment option for obstructive sleep apnea in selected patients. A unilateral hypoglossal nerve stimulation system was approved a decade ago, yet the physiological effect of unilateral hypoglossal stimulation on bilateral tongue motion remains unclear. This study examined how electrode configuration, stimulation cuff position, or body mass index influenced the contralateral genioglossus electromyography (EMG) signal. Twenty-nine patients underwent three EMG recordings in a polysomnographic setting after being implanted with a unilateral hypoglossal nerve stimulator for at least 6 months. The ratio of EMG signals between the ipsi- and contralateral sides was evaluated. No difference in EMG signals was demonstrated based on electrode configurations, stimulation-cuff position, body-mass-index, or sleep apnea severity, even in patients with right tongue protrusion only. Our findings may be explained by a significant level of cross-innervation and by a smaller and less variable circumferential electric field than expected based on prior biophysical models. A patient's individual anatomy needs to be considered during therapy titration in order to achieve an optimal response.

Valve-sparing root replacement after the Ross procedure

ObjectivesThe Ross procedure is a preferred treatment for infants and children with aortic valve disease. Progressive neoaortic root dilation and neoaortic insufficiency can occur after the Ross procedure, and because of the young age of these patients, valve-sparing aortic root replacement procedures have advantages compared with the Bentall procedure. The aim of this study is to describe our experience with different techniques of aortic valve-sparing root replacement in this unique cohort of patients. MethodsPatients undergoing valve-sparing aortic root replacement with a history of the Ross procedure between January 2001 and March 2021 were identified. A retrospective chart review was performed, and clinical characteristics of these patients were analyzed. The results of different types of valve-sparing aortic root replacement were also compared. ResultsForty-two patients who had previously undergone a Ross procedure in childhood presented for reintervention for neoaortic root or valve pathology. Seventeen of these patients were considered for valve-sparing aortic root replacement but underwent bioprosthetic or mechanical valve replacement, and 25 patients underwent successful valve-sparing aortic root replacement. Patients who underwent valve-sparing aortic root replacement received a traditional aortic root remodeling procedure with or without suture annuloplasty (Yacoub technique, group 1, n = 7), an aortic root reimplantation procedure (David technique, group 2, n = 11), or a modified root remodeling procedure that also used a geometric annuloplasty ring (group 3, n = 7). Patient demographics and comorbidities were similar between groups. Mean follow-up for these 3 cohorts was 14 years, 4 years, and 1 year, respectively. Overall survival was good, with 1 early death due to hemorrhage in group 2 and 1 death due to malignancy in group 1. Eight patients (7 in group 1; 1 in group 2) required subsequent aortic valve replacements due to neoaortic insufficiency, whereas none in group 3 have required any reintervention. Overall, patients requiring valve replacement after valve-sparing aortic root replacement had lower grades of preoperative neoaortic insufficiency and higher grades of postoperative neoaortic insufficiency. Greater than mild postoperative neoaortic insufficiency was associated with the need for subsequent neoaortic valve replacement. ConclusionsValve-sparing aortic root replacement is safe in patients with a prior Ross procedure. Reimplantation offers superior durability compared with the traditional remodeling procedure. Greater than mild neoaortic insufficiency on postoperative echocardiogram should prompt additional attempts at valve repair. A modified remodeling procedure with geometric ring annuloplasty that is personalized to the patient's individual anatomy is safe with good short-term results, but longer follow-up is needed.

MRI and Anatomical Determinants Affecting Neuroforaminal Stenosis Evaluation: A Descriptive Observational Study.

PurposeNeuroforaminal stenosis (NFS), a narrowing of the intervertebral foramen, is a cause of disability in the aging population. Formal magnetic resonance imaging (MRI) classification of NSF has been developed recently and contradictory findings have been reported. This study aims to assess whether in-plane, anatomically conformed two-dimensional (2D) views of the neuroforamen characterize NFS more accurately than traditional axial, coronal, and sagittal views in healthy individuals with and without simulated scoliosis.Patients and methodsThis observational study was approved by the designated institutional review board at our academic tertiary care center. Four volunteers underwent lumbar spine MRI twice, once in the supine position and once with intentionally introduced hip tilt. The latter resulted in lumbar curvature mimicking positioning errors approximating degenerative lumbar scoliosis. Anatomically oriented cuts such as axial with endplate correction and coronally obliqued parasagittals, also called coronal obliques, were performed. Standard sagittal and axial views were also performed in both the supine and rotated groups.ResultsCoronal oblique and anatomically oriented axial views demonstrated the highest correlation with true neuroforaminal caliber. Deviation from anatomical congruence resulted in false measurements of neuroforaminal size. The hip-tilt studies produced MR that were less favorable to characterization of the caliber of neuroforamina. Coronal sections demonstrated reliability only when performed at the mid-pedicular lines. Standard axial views were reliable only when taken at the upper one-third of the neuroforamen. Coronal oblique views demonstrated superiority when evaluating consecutive neuroforamen on one image compared to non-obliqued parasagittal slices.ConclusionTo minimize error in neuroforaminal analysis, imaging specialists should perform anatomically oriented cuts to conform to individual patient anatomy. When this cannot be performed due to a patient’s spine rotation or position, the MRI reader should view oblique, axial, and coronal images simultaneously and dynamically for proper foraminal characterization.

Posterior Cloaca: Multicenter Experience of a Very Rare and Unusual Anorectal and Genitourinary Malformation.

Posterior cloacal malformations (PCMs) are distinguished from classical cloacal malformations by the posterior location of the common opening in the perineum. We aim to describe our experience of management of these rare and complex malformations. This study was a retrospective chart review of all patients with PCM who underwent treatment at Kalawati Saran Children's Hospital (KSCH), New Delhi, and Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, between 2013 and 2021. Individual anatomical variations and their impact on the clinical presentation, management, and final outcome (cosmesis and function) were recorded and analyzed. During the study period, four girls with a median age of 2 (range: 0-5) years presented to us with PCM. Three patients were referred to KSCH as ambiguous genitalia whereas one patient was born at SGPGIMS with an antenatal diagnosis of "urorectal septal defect." On examination, three patients had the urogenital sinus (UGS) opening immediately anterior to the normally located anal opening (2 orifices), whereas one had a single orifice at the normal location of the anus with the UGS opening in the anterior rectal wall. Associated anomalies included: (a) hydrocolpos (n = 3), which was managed by a tube vaginostomy; (b) urethral duplication with dorsal atretic urethra (n = 3); (c) uterine didelphys (n = 1); (d) bilateral grade 5 vesicoureteric reflux (n = 1); and (e) vaginal calculus (n = 1). Total urogenital mobilization (anterior sagittal approach) with feminizing genitoplasty was performed for patients with UGS and normal anus (n = 3). In the patient with a single opening at the normal location of the anus, posterior sagittal ano-recto-urethro-vaginoplasty was performed. At a median follow-up of 24 months, three patients are continent for urine and stool, whereas one patient is yet to be toilet trained. PCMs are unusual complex malformations that necessitate meticulous clinical examination, detailed diagnostic workup, and multistaged surgical management. Management should be tailored as per each individual patient's anatomy and clinical presentation for an optimal outcome.

Evaluation of Anatomoradiological Findings on Trigeminal Neuralgia Patients Using Computed Tomography and Cone-Beam Computed Tomography.

The study aimed to establish and evaluate anatomoradiological landmarks in trigeminal neuralgia patients using computed tomography (CT) and cone-beam CT. CT images of 40 trigeminal neuralgia (TN) and 40 healthy individuals were retrospectively analyzed and enrolled in the study. The width and length of the foramen rotundum (FR), foramen ovale (FO), foramen supraorbitale, and infraorbitale were measured. The distances between these foramen, between these foramen to the median plane, and between the superior orbital fissure, FO, and FR to clinoid processes were also measured bilaterally. Variations were evaluated according to groups. Significant differences were found for width and length of the foramen ovale, length of the foramen supraorbitale, and infraorbitale between TN and control subjects (p < 0.05). On both sides, FO gets narrower and the length of the infraorbital and supraorbital foramen shortens in the TN group. In most of the control patients, the plane which passes through the infraorbital and supraorbital foramen intersects with impression trigeminale; 70% on the right-side, and 67% in the left-side TN groups. This plane does not intersect with impression trigeminale and deviates in certain degrees. The determination of specific landmarks allows customization to individual patient anatomy and may help the surgeon achieve a more selective effect with a variety of percutaneous procedures in trigeminal neuralgia patients.

Effects of laser interstitial thermal therapy for mesial temporal lobe epilepsy on the structural connectome and its relationship to seizure freedom.

Laser interstitial thermal therapy (LITT) is a minimally invasive surgery for mesial temporal lobe epilepsy (mTLE), but the effects of individual patient anatomy and location of ablation volumes affect seizure outcomes. The purpose of this study is to see if features of individual patient structural connectomes predict surgical outcomes after LITT for mTLE. This is a retrospective analysis of seizure outcomes of LITT for mTLE in 24 patients. We use preoperative diffusion tensor imaging (DTI) to simulate changes in structural connectivity after laser ablation. A two-step machine-learning algorithm is applied to predict seizure outcomes from the change in connectomic features after surgery. Although node-based network features such as clustering coefficient and betweenness centrality have some predictive value, changes in connection strength between mesial temporal regions predict seizure outcomes significantly better. Changes in connection strength between the entorhinal cortex (EC), and the insula, hippocampus, and amygdala, as well as between the temporal pole and hippocampus, predict Engel Class I outcomes with an accuracy of 88%. Analysis of the ablation location, as well as simulated, alternative ablations, reveals that a more medial, anterior, and inferior ablation volume is associated with a greater effect on these connections, and potentially on seizure outcomes. Our results indicate (1) that seizure outcomes can be retrospectively predicted with excellent accuracy using changes in structural connectivity, and (2) that favorable connectomic changes are associated with an ablation volume involving relatively mesial, anterior, and inferior locations. These results may provide a framework whereby individual pre-operative structural connectomes can be used to optimize ablation volumes and improve outcomes in LITT for mTLE.