Guidance For Placement Research Articles

Development of risk mitigation guidance for sensor placement inside mechanically ventilated enclosures – Phase 1

Guidance on Sensor Placement was identified as the top research priority for hydrogen sensors at the 2018 HySafe Research Priority Workshop on hydrogen safety in the category Mitigation, Sensors, Hazard Prevention, and Risk Reduction. This paper discusses the initial steps (Phase 1) to develop such guidance for mechanically ventilated enclosures. This work was initiated as an international collaborative effort to respond to emerging market needs related to the design and deployment equipment for hydrogen infrastructure that is often installed in individual equipment cabinets or ventilated enclosures. The ultimate objective of this effort is to develop guidance for an optimal sensor placement such that, when integrated into a facility design and operation, will allow earlier detection at lower levels of incipient leaks, leading to significant hazard reduction. Reliable and consistent early warning of hydrogen leaks will allow for the risk mitigation by reducing or even eliminating the probability of escalation of small leaks into large and uncontrolled events. To address this issue, a study of a real-world mechanically ventilated enclosure containing GH2 equipment was conducted, where CFD modeling of the hydrogen dispersion (performed by AVT and UQTR, and independently by the JRC) was validated by the NREL Sensor laboratory using a Hydrogen Wide Area Monitor (HyWAM) consisting of a 10-point gas and temperature measurement analyzer. In the release test, helium was used as a hydrogen surrogate. Expansion of indoor releases to other larger facilities (including parking structures, vehicle maintenance facilities and potentially tunnels) and incorporation into QRA tools, such as HyRAM is planned for Phase 2. It is anticipated that results of this work will be used to inform national and international standards such as NFPA 2 Hydrogen Technologies Code, Canadian Hydrogen Installation Code (CHIC) and relevant ISO/TC 197 and CEN documents.

The Impact of a Comprehensive Simulation-Based Training and Certification Program on Resident Central Venous Catheter Complication Rates.

Millions of central venous catheters (CVCs) are placed annually in the United States, many by resident physicians. Simulation training has been proposed as a means to increase resident physician competence with CVC placement and decrease the incidence of line-associated mechanical complications. We aimed to evaluate the impact of a novel simulation-based CVC training program for resident physicians on CVC-associated mechanical complication rates. We hypothesized that the CVC-related mechanical complication rates would be lower among simulation-trained residents (STRs) compared with nonsimulation, traditionally trained residents (TTRs). A retrospective chart review was performed of patients with a CVC placed by a resident physician between October 2014 and January 2017 at MedStar Georgetown University Hospital in Washington, DC. Incidence of CVC mechanical complications, including pneumothorax, hemothorax, arterial injury, or retained guidewire, were extracted from the electronic medical record and compared between STR and TTR cohorts. In contrast to TTRs who were trained to place CVCs in a supervised clinical setting, STRs underwent a CVC training program using online modules, a hands-on simulation training and testing checklist, and a series of successful supervised insertions before being credentialed to place lines independently. Nine hundred twenty-four CVCs placed by resident physicians during the study period were analyzed. There was no statistically significant difference in total mechanical complication rates between the STRs and TTRs in this study period (2.4% vs. 2.2%, P = 1). Simulation-trained residents were more likely to use ultrasound guidance when indicated during CVC insertion compared with TTRs (94.8% vs. 70.5%, P < 0.001). Mechanical complication rates associated with CVC insertion were similar between the simulation and TTRs and were consistent with previously published literature. These findings suggest that residents who underwent simulation training and certification demonstrated performance on par with more experienced TTRs. In addition, they were more likely to use best practices including ultrasound guidance in line placement.

Use of ultrasound guidance in central venous catheter placement by emergency physicians in Saudi Arabia.

Objectives:To determine the ultrasound guidance for central venous catheter (USG-CVC) placement rate of emergency physicians (EPs) in Kingdom of Saudi Arabia.Methods:A cross-sectional survey study regarding the respondents’ demographic profiles, formal and informal training in USG-CVC placement, experiences, and attitudes towards the procedure was emailed to all EPs registered with the Saudi Commission for Health Specialties (SCFHS) between October and December 2018.Results:In total, 234/350 SCFHS-registered EPs completed the survey; the response rate was 66.9%. Most respondents (70.5%) were board-certified in emergency medicine (EM). Ninety percent indicated that US device for CVC placement assistance was available. Most EPs (78.2%) had performed USG-CVC placement; the US usage rate correlated significantly with recent graduation from residency (p=0.048). In total, 83.3% received formal training during residency. Of the 234 respondents, 53.8% felt extremely comfortable with CVC placement with USG and 19.7% without USG (p<0.01). Nevertheless, most respondents desired further USG-CVC training.Conclusion:Despite existing evidence and a consensus on its superiority over the landmark technique, USG-CVC placement has not been adopted by a small proportion of EPs into clinical practice. Formal training, education, and institutional provision of permanent onsite US machines may address any barriers.

Role of intraoperative ultrasound in robotic-assisted radical nephrectomy with inferior vena cava thrombectomy in renal cell carcinoma.

To determine the impact of intraoperative ultrasound on robotic-assisted radical nephrectomy with inferior vena cava (IVC) tumor thrombectomy in renal cell carcinoma (RCC). We retrospectively analyzed intraoperative records of 27 patients with RCC and invasion of the IVC who underwent robotic-assisted nephrectomy with tumor thrombectomy at our center between December 2017 and July 2018. Diagnostic utility and impact of intraoperative transesophageal echocardiography (TEE), intraoperative robotic-assisted ultrasonography, and intraoperative contrast-enhanced ultrasound (CEUS) on surgical management were extracted from the surgical notes and intraoperative ultrasound reports. Twenty-seven patients with thrombus had intraoperative ultrasound. Complete tumor removal was achieved in 22 patients, IVC transection in 5 patients, and no residual tumor was observed in all patients. Intraoperative TEE changed the robotic surgical strategy in three patients by monitoring thrombus-level regression. Downstaging of the thrombus level occurred in three patients: Levels IV to III in one and Levels III to II in two. Intraoperative robotic-assisted ultrasonography has facilitated safe VC clamp placement and identification and protection of collateral vessels during IVC transection in five patients. Intraoperative CEUS helped to differentiate the boundary between tumor thrombus (enhancement and small vessel pulsation) and bland thrombus (hypoechoic or no enhancement) in eight (29.6%) patients with bland thrombus. Intraoperative ultrasound is a safe, minimally invasive technique that can provide accurate real-time information regarding the presence and extent of IVC involvement and guidance for placement of a vena cava clamp, confirming the character of the thrombus to plan an optimal surgical approach.

Radiographic assessment of the cup orientation after total hip arthroplasty: a literature review.

Optimal acetabular cup orientation is of substantial importance to good long-term function and low complication rates after total hip arthroplasty (THA). The radiographic anteversion (RA) and inclination (RI) angles of the cup are typically studied due to the practicability, simplicity, and ease of interpretation of their measurements. A great number of methods have been developed to date, most of which have been performed on pelvic or hip anteroposterior radiographs. However, there are primarily two influencing factors for these methods: X-ray offset and pelvic rotation. In addition, there are three types of pelvic rotations about the transverse, longitudinal, and anteroposterior axes of the body. Their effects on the RA and RI angles of the cup are interactively correlated with the position and true orientation of the cup. To date, various fitted or analytical models have been established to disclose the correlations between the X-ray offset and pelvic rotation and the RA and RI angles of the cup. Most of these models do not incorporate all the potential influencing parameters. Advanced methods for performing X-ray offset and pelvic rotation corrections are mainly performed on a single pelvic AP radiograph, two synchronized radiographs, or a two-dimensional/three-dimensional (2D-3D) registration system. Some measurement systems, originally developed for evaluating implant migration or wear, could also be used for correcting the X-ray offset and pelvic rotation simultaneously, but some drawbacks still exist with these systems. Above all, the 2D-3D registration technique might be an alternative and powerful tool for accurately measuring cup orientation. In addition to the current methods used for postoperative assessment, navigation systems and augmented reality are also used for the preoperative planning and intraoperative guidance of cup placement. With the continuing development of artificial intelligence and machine learning, these techniques could be incorporated into robot-assisted orthopaedic surgery in the future.

Intracavitary electrocardiogram guidance for placement of peripherally inserted central catheters in premature infants.

This study evaluated the accuracy of intracavitary electrocardiogram (IC-ECG) guidance for placement of peripherally inserted central catheters (PICCs) in premature infants, relative to chest X-ray.Premature infants (n = 173) underwent placement of a PICC monitored by ECG, and a stable heart rhythm was shown. Changes in the P wave of the ECG reflected the position of the catheter tip, and a characterized P wave indicated the correct position. The P wave results were compared with a chest X-ray.P wave changes were observed in 157 (90.75%) of the premature infants on the ECG. Among them, the catheter tips of 148 (85.55%) and nine (5.20%) patients were in the correct and non-correct position, respectively, which was confirmed by chest X-ray. No characteristic P wave changes were observed in 16 (9.32%) patients on ECG, in which the catheter tips of eight (4.62%) patients each were in the correct and non-correct position, according to the chest X-ray. The accuracy of IC-ECG guidance for placement of the PICC was 90.17%. The PICC tip location results of the IC-ECGs were statistically similar to that of the chest X-rays.IC-ECG guidance is accurate for placement of PICC in premature infants, and provides an economical assessment without radiation.

2006 Epigastric Artery Aneurysm Bleeding Post-Percutaneous Endoscopic Gastrostomy

INTRODUCTION: Percutaneous endoscopic gastrostomy (PEG) is commonly used to provide enteral nutrition in patients unable to maintain adequate nutrition orally. There is limited data on aneurysmal bleeding following PEG. When this occurs, it is typically severe and is a life-threatening complication leading to hemorrhagic shock. Prompt recognition and treatment are imperative to survival. Extensive literature review revealed five case reports of post-PEG pseudoaneurysm. We present a summary of reported cases and their respective management. CASE DESCRIPTION/METHODS: We present a case of a 50-year-old female, status post orthotopic liver transplant, who had a complicated post-op course and ICU stay. The patient developed a cerebral infarct in Pons region which led to dysphagia. Therefore underwent PEG tube placement by “pull” technique. Later on, the patient experienced recurrent episodes of PEG site bleeding. She underwent EGD which showed massive upper GI bleed from percutaneous endoscopic gastrostomy fistula tract. Hemostasis was initially achieved using bear claw but also required endoclips and surgical intervention in the end. CT imaging revealed a pseudoaneurysm at the PEG site within the rectus muscle, arising from the epigastric artery, measuring 19.8 mm × 17.8 mm. It was treated with thrombin injection. The resolution of aneurysmal bleed was confirmed on follow up imaging. DISCUSSION: We found 5 similar cases with patients 70 to 85 years old, who predominantly had a pull technique PEG tube placement. Imaging confirmed gastrostomy site pseudoaneurysm, involing left gastric or gastroepiploic artery, was a complication in all cases which were either treated by lipiodol injection, angiographic embolization and/or thrombin injection. Our patient had a pseudoaneurysm involving epigastric artery which is a novel presentation. Placement of PEG with transillumination carries a risk of rare complication if inserted in an upper triangle involving superior epigastric artery. Therefore an attempt must be made to keep PEG away from the superior epigastric triangle. Pull technique is used much more commonly and It is unlikely to be the cause of these aneurysmal complications however, data is limited and more review studies are needed. Also, more evidence is needed to compare outcomes of the transillumination method vs US/fluoroscopic guidance placement.

3D image-guided surgery for fragility fractures of the sacrum.

Stabilizing sacral fragility fractures without radiation exposure to the surgical team. Non-displaced or minimally displaced unilateral or bilateral transalar, transforaminal or central sacral fractures in weak and osteoporotic bone. Displaced or highly unstable sacral fractures. Patients under therapeutic anticoagulation. Patients needing fast track orthopedic surgery. Prone position. Reference clamp installation on posterior iliac crest. Initial 3D scan of posterior pelvic ring. Image-guided virtual determination of 2-3interforaminal iliosacroiliac trajectories in sacral vertebraeI andII. Lateral transgluteal mini-open approach. 3D image-guided insertion of 2-3guide wires along planned trajectories. 3D-scan for controlling guide wire positions. Virtual determination of screw lengths. Cortical drilling and cannulated screw insertion along guide wires. Radiological documentation. Clinical and radiological follow-up after 12weeks, 12 and 24months including radiographs in anteroposterior, lateral, inlet and outlet views. From October 2011 until October 2016 atotal of 124 sacral fracture sites (in sacral vertebraeI andII) were treated with 120 navigated sacral screws in 52patients (48females, 4males; mean age 76 ± 10 years, range 36-90 years) using 3D image guidance for screw placement. Image-guidance accuracy was 99.2% (119/120 screws correctly placed). Complications comprised revision surgery for subfascial hematoma evacuation (n = 1) and screw removal due to loosening after 12weeks (n = 2). Four patients died before final follow-up. Mean pain visual analogue scale (VAS) decreased from 8.9 ± 1.1 (presurgery value) over 3.6 ± 1.7 (postsurgery value) to 1.8 ± 1.9 (2-year follow-up value), mean Oswestry disability index (ODI) improved from 86.2 ± 4.9% (presurgery value) over 28.5 ± 9.5% (postsurgery value) to 23.3 ± 13.7% (2-year follow-up value).

Improved respiratory motion tracking through a novel fiducial marker placement guidance system during electromagnetic navigational bronchoscopy (ENB)

BackgroundStereotactic ablative radiotherapy (SABR) is a treatment option for patients with early stage non-small cell lung cancer (NSCLC) and recurrent or oligometastatic disease who are not surgical candidates. Due to the continuous motion of tumors within the lungs, implementing a strategy to track the target lesion is crucial. One method is to place fiducial markers which the robotic SABR system is able to track during treatment. However, placing these markers in a manner that maximizes tracking efficacy can be challenging. Using a novel fiducial placement guidance system (FPGS) during fiducial deployment may offer a way to improve the quantity of fiducials tracked by the robotic SABR system.MethodThis was an institutional, retrospective review identifying all patients who received robotic SABR for lung tumors from May 2015 until January 2017. The FPGS was instituted in May 2016. The median number of fiducials tracked and the rate of complication was compared between patients whose fiducials were placed using FPGS versus those that were not.ResultsA total of 128 patients with 147 treated lung lesions were identified. Of the lesions that utilized FPGS (n = 44), 28 had 2 tracked fiducials (63.6%), 14 had 3 (31.8%) and 2 had 4 (4.6%). Of the lesions treated without FPGS (n = 103), 5 had 1 tracked fiducial (4.9%), 91 had 2 (88.4%), 6 had 3 (5.8%), and 2 had 4 (1.9%). A significant improvement in the median number of fiducials tracked per fraction was observed for the lesions with fiducials placed using FPGS on Wilcoxon rank sum test (p < 0.001). The rate of complication was low and not statistically different between cohorts (p = 0.44).ConclusionsThe FPGS can be used during the deployment of fiducial markers and may increase the number of fiducials tracked.Trial registrationAn exemption for this retrospective review was granted by the East Carolina University IRB under UMCIRB 15-001726.

Relationship between forehead motion and the shape of forehead lines-A 3D skin displacement vector analysis.

Neuromodulator injections of the forehead are often performed using standardized protocols. This study was designed to identify the individual skin motion pattern of the forehead and to relate this pattern to the underlying frontalis muscle morphology to offer guidance for neuromodulator placement. Thirty-seven healthy volunteers (29 Caucasians, six African Americans, two Asians) with a mean age of 39.84±14.4years [range: 22-73] were enrolled. 3D images of the forehead were analyzed using a Vectra H1 camera system computing skin displacement vectors between the noncontracted and the maximally contracted forehead of the volunteers. Relationships between the shape of the horizontal forehead lines (straight vs wavy) and the forehead motion pattern were calculated. Independent of age or gender, a greater forehead motion angle was associated with the presence of wavy forehead lines 21.34°±5.9 with P<0.001, whereas straight forehead lines were associated with a smaller forehead motion angle 6.68°±2.9 P<0.001. Females had more frequently straight horizontal forehead lines versus males: 68.4% vs 44.4% (P=0.037). Young volunteers (<39.8years) did not differ in their mean forehead motion angle when compared to older volunteers (>39.8years): 13.70°±9.0 vs 12.39°±8.0 with P=0.530. Injections of neuromodulators in the forehead can be individualized by respecting the shape of the horizontal forehead lines. Wavy lines require injection points that are located more laterally, whereas straight lines require more centrally located injection points.

Barriers to ultrasound guidance for central venous access: a survey among Dutch intensivists and anaesthesiologists

Accumulating evidence shows that ultrasound (US) guidance improves effectiveness and safety of central venous catheter (CVC) placement. Several international guidelines therefore recommend the use of US for placement of CVCs. However, surveys show that the landmark-based technique is still widely used, while the percentage of physicians using US is increasing less than expected. The goal of this study was to investigate current practice for central venous catheterization in anaesthesiology and intensive care in the Netherlands, identify barriers for further implementation of US guidance and to evaluate whether personality traits are associated with the choice of technique. We conducted a web-based national survey, distributed among members of the Dutch societies of anaesthesiology (NVA) and intensive care (NVIC). The survey contained questions regarding physician and hospital characteristics, frequency of US use and reasons for use or non-use, as well as the NEO-FFI-3, a validated, translated questionnaire to characterize personality traits according to the ‘Big Five’ concept. Response rate was 22% (506/2291), of which 400 had also the personality questionnaire complete. Ultrasound guidance was used always or almost always in 68%; barriers for US use were working in a non-academic non-teaching hospital, providing cardiac anaesthesia and more years of physician experience. Reasons for not using US were perceived lack of benefit, increased procedure time, lack of US equipment and fear of loss of landmark technique skills. 13% of respondents had never experienced a complication during CVC placement, and 67% knew of a complication occurring the past year at their department. Ultrasound was thought not to be able to prevent the complication in half of these cases. Of the personality traits, only neuroticism and extraversion showed a minor positive association with US guidance. A majority of anaesthesiologists and intensivists uses US guidance for CVC placement, but a significant proportion of physicians still prefers the landmark technique. Most arguments from respondents against US guidance can be challenged. Personality traits most likely do not play a major role in the acceptance of US guidance for central venous catheterization. A potential intervention to increase US use could be formalizing local hospital policies mandating compliance with US guidance. Future research can perhaps focus on cognitive biases that currently limit more widespread use of US guidance.

Postdural Puncture Headache in a Postpartum Female With Previous Spinal Surgery—Successful Treatment With Caudal Epidural Blood Patch: A Case Report

The occurrence of a postdural puncture headache (PDPH) is a known risk associated with epidural procedures. The primary nonconservative treatment option for PDPH is the performance of an epidural blood patch. This case report describes the use of image guidance for placement of a caudal epidural to treat a PDPH in a postpartum patient. A caudal catheter was placed under real-time guidance and visualization of the deposition of the blood was obtained. By entering via the caudal foramen and utilizing a catheter, manipulations in catheter placement could be performed to adjust deposition of the blood.

Evaluation of Multi-Slice Spiral Computed Tomography in In vivo Simulation of Individualized Cervical Pedicle Screw Placement at C3-C7 in Chinese Healthy Population.

Background:Cervical pedicle screw fixation through posterior approach has shown greater cervical stability advantage. The cervical pedicle screw fixation technique through posterior approach is demanding. The key to the technique is the choice of point and angle of screw entrance. The angle of screw placement is variable. Morphometric measurements of the cervical pedicle are a prerequisite for individualized screw. CT imaging has become the most reliable and important means to obtain cervical pedicle's measurement data and morphology in vivo. This study explores the feasibility and application of precise in vivo measurements by multi-slice computed tomography (MSCT) for individualized cervical transpedicular screw placement at C3–C7 in Chinese healthy population.Materials and Methods:80 adults who underwent cervical examination by enhanced and nonenhanced computed tomography angiography, respectively, were selected and submitted to bone algorithm reconstruction for slice thickness and interval of 0.75 mm to acquire clear images and detailed bone structures. Simulation of individualized screw placement was performed with a 4.0 mm diameter screw with the help of postprocessing workstation. Pedicle transverse angle (PTA) and sagittal angle (PSA) were measured using the single- and double-line methods (analog nailing, 4.0 mm in diameter) in 160 pairs of C3–C7 pedicles, setting positive and negative values for cranial direction and foot side PSAs, respectively. Comparison of the measured change scope in PTA and PSA between the two methods was carried out; the range was defined as the error range.Results:Significantly, different results (P < 0.05) were obtained between the single- and double-line methods in the error ranges of PTA and PSA in C3–C7 pedicles. Interestingly, the double-line method was better in simulating the actual needs of individualized nailing. The mean values of PTA and PSA were 42.9°, 45.5°, 42.4°, 37.1°, 29.0° and 8.4°, 5.0°, −4.0°, and −7.8°, −8.1°, respectively, with the double-line method.Conclusion:MSCT reconstruction techniques can determine the direction and required parameters for individualized screw placement. In addition, accurate in vivo measurements of PTA and PSA, particularly PSA, provide the orthopedic surgeon with theoretical guidance and reliable basis in screw placement.

Multiple refinements to the anaesthetic protocol for laparoscopic orthotopic kidney auto-transplantation in a pig model.

Fifty-four pigs ( Sus scrofa, Large White cross) from a commercial pig farm were anaesthetised over a six-year period from October 2011. The procedural stages included initial instrumentation for intra-operative monitoring, laparoscopic nephrectomy, preparation of the kidney graft, orthotopic auto-transplantation by either a laparoscopic approach or an open surgical approach, and ligation of the contralateral ureter. During the evolution and establishment of this pig model multiple refinements were introduced: (1) a heat pad was changed to a circulating warm air blanket; (2) routine administration of anticholinesterase and antimuscarinic drugs for reversal of neuromuscular blockade; (3) a technique for urethral catheterisation was developed; (4) ultrasound guidance for placement of a central venous line was learned; (5) intravenous infusions of morphine and ketamine were instituted for a more stable and balanced anaesthetic protocol; and (6) post-operative monitoring was performed by two technical staff for at least the first six hours after extubation of the trachea. The combination of refinements to the anaesthesia protocol for laparoscopic orthotopic kidney auto-transplantation over the first 54 pigs has translated to improved outcomes. This conclusion is entirely subjective as accurate measurement of the impact of each refinement is impossible. Nevertheless, refinement is a continuous process and should be applied to the entire range of procedures involved in animal use for scientific purposes.

Neuromuscular Ultrasound: A New Tool in Your Toolbox.

Neuromuscular ultrasound is a rapidly evolving technique for diagnosing, monitoring and facilitating treatment of patients with muscle and nerve disorders. It is a portable point-of-care technology that is non-invasive, painless and without ionizing radiation. Ultrasound can visualize muscle texture alterations indicating dystrophy or denervation, changes in size and anatomic continuity of nerve fascicles, and its dynamic imaging capabilities allow capturing of contractions and fasciculations. Ultrasound can also provide real-time guidance for needle placement, and can sometimes make a diagnosis when electromyography is not tolerated or not informative anymore. This review will focus on the technical and practical aspects of ultrasound as an imaging technique for muscles and nerves. It will discuss basic imaging principles, hardware and software setup, and provide examples of ultrasound use for visualizing muscle and nerve abnormalities with accuracy and confidence. The review is intended as a practical "how-to" guide to get started with neuromuscular ultrasound in daily practice.

Percutaneous Gastrostomy: How to Recognize, Avoid, or Get Out of Trouble

Placement of gastrostomy tubes can be done with different techniques. The radiologic-guided tube placement relies on image guidance for safe placement of the tube. A thorough knowledge of the immediate and delayed hazards is essential. This article outlines the potential complications and how to recognize, avoid, and treat them. Several clinical examples are included. Key Words: gastrostomy, complication, feeding tubes, image guidance.

Clinical Experience with Real-Time 3-D Guidance Based on C-Arm-Acquired Cone-Beam CT (CBCT) in Transjugular Intrahepatic Portosystemic Stent Shunt (TIPSS) Placement.

The aim of this study was to evaluate the feasibility of cone-beam computed tomography (CBCT)-based real-time 3-D guidance of TIPSS placement and its positioning compared to standard guiding methods. In a prospective, randomized, consecutive study design from 2015 to 2017, we included 21 patients in the CBCT guided group and 15 patients in the ultrasound (US) guided group. The prospective groups were compared in terms of success rate of intervention, portal vein puncture/procedure time, number of puncture attempts and applied dose. We furthermore retrospectively analyzed the last 23 consecutive cases with fluoroscopic guided portal vein puncture in terms of success rate, procedure time and applied dose, as it has been the standard method before US guidance. The median number of puncture attempts (CBCT: n=2, US: n=4, p=0.249) and the mean puncture time (CBCT: 32±45min, US: 36±45min, p=0.515) were not significantly different. There were furthermore no significant differences in the mean time needed for the total TIPSS procedure (CBCT: 115±52min, US: 112±41min, fluoroscopy: 110±33min, p=0.996). The mean applied dose of the complete procedure also showed no statistically significant differences (CBCT: 563±289Gy·cm2, US: 322±186Gy·cm2, fluoroscopy: 469±352Gy·cm2, p=0.069). There were no image guidance related complications. Real-time 3-D needle guidance based on CBCT is feasible for TIPSS placement. In terms of puncture attempts, duration and dose, CBCT guidance was not inferior to the control groups and may be a valuable support for interventionists in TIPSS procedures.

Clinical Outcome of Total Knee Arthroplasty Performed Using Patient-Specific Cutting Guides.

BackgroundPatient-specific instruments have recently gained attention for ensuring the accuracy of osteotomy and correct alignment in total knee arthroplasty (TKA). We aimed to report our experience with TKA performed by using CT-based 3D model of cutting guides in our clinic.Material/MethodsA total of 36 patients (mean age, 67.58±8.46 years; 24 females, 12 males) who underwent TKA with 3D patient-specific cutting guides in our clinic were included in the study. Differences between preoperatively planned bone resections and actual bone resections were calculated. Femoral and tibial component angles were measured on radiographs of the knee. The change in knee pain was evaluated by patients on a 10-point visual analog scale (VAS). Patients were followed up for 6 months postoperatively.ResultsThe actual bone resection was 0.5–1.5 mm higher than the planned resection for all sides, being statistically significant for posterior lateral and distal medial sides (1.1±1.3 mm and 1.5±0.9 mm, respectively; p<0.05). On postoperative radiographs, coronal tibial component angle was 88.8°±0.9° and coronal femoral component angle was 95.2°±1.6°, showing good postoperative alignment. The VAS pain score of patients significantly decreased from preoperative 3.9±0.8 to 1.1±0.9 at 6 months after the operation. One patient developed superficial tissue infection on postoperative follow-up, which was effectively treated. No other pathology was detected in the postoperative period.ConclusionsPatient-specific cutting guides can provide intraoperative guidance for better placement of the implant in TKA and increase the accuracy of osteotomy and postoperative alignment.

A Preliminary Study on Precision Image Guidance for Electrode Placement in an EEG Study.

Conventional methods for positioning electroencephalography electrodes according to the international 10/20 system are based on the manual identification of the principal 10/20 landmarks via visual inspection and palpation, inducing intersession variations in their determined locations due to structural ambiguity or poor visibility. To address the variation issue, we propose an image guidance system for precision electrode placement. Following the electrode placement according to the 10/20 system, affixed electrodes are laser-scanned together with the facial surface. For subsequent procedures, the laser scan is conducted likewise after positioning the electrodes in an arbitrary manner, and following the measurement of fiducial electrode locations, frame matching is performed to determine a transformation from the coordinate frame of the position tracker to that of the laser-scanned image. Finally, by registering the intra-procedural scan of the facial surface to the reference scan, the current tracking data of the electrodes can be visualized relative to the reference goal positions without manually measuring the four principal landmarks for each trial. The experimental results confirmed that use of the electrode navigation system significantly improved the electrode placement precision compared to the conventional 10/20 system (p < 0.005). The proposed system showed the possibility of precise image-guided electrode placement as an alternative to the conventional manual 10/20 system.

Kōkōshūshokushidō no shakaigaku: ‘Nihongata’ ikō o saikō suru (Sociology of Senior High School Job Placement Guidance: Reconsideration of the ‘Japanese Type’ Transition)

Kōkōshūshokushidō no shakaigaku: ‘Nihongata’ ikō o saikō suru (Sociology of Senior High School Job Placement Guidance: Reconsideration of the ‘Japanese Type’ Transition)