Real-time Fluoroscopic Images Research Articles

Use of surgical augmented intelligence maps can reduce radiation and improve safety in the endovascular treatment of complex aortic aneurysms

ObjectiveThe introduction of endovascular procedures has revolutionized the management of complex aortic aneurysms. Although repair has traditionally required longer operative times and increased radiation exposure compared with simple endovascular aneurysm repair, the recent introduction of three-dimensional technology has become an invaluable operative adjunct. Surgical augmented intelligence (AI) is a rapidly evolving tool initiated at our institution in June 2019. In our study, we sought to determine whether this technology improved patient and operator safety. MethodsA retrospective review of patients who had undergone endovascular repair of complex aortic aneurysms (pararenal, juxtarenal, or thoracoabdominal), type B dissection, or infrarenal (endoleak, coil placement, or renal angiography with or without intervention) at a tertiary care center from August 2015 to November 2021 was performed. Patients were stratified according to the findings from intelligent maps, which are patient-specific AI tools used in the operating room in conjunction with real-time fluoroscopic images. The primary outcomes included operative time, radiation exposure, fluoroscopy time, and contrast use. The secondary outcomes included 30-day postoperative complications and long-term follow-up. Linear regression models were used to evaluate the association between AI use and the main outcomes. ResultsDuring the 6-year period, 116 patients were included in the present study, with no significant differences in the baseline characteristics. Of the 116 patients, 76 (65.5%) had undergone procedures using AI and 40 (34.5%) had undergone procedures without AI software. The intraoperative outcomes revealed a significant decrease in radiation exposure (AI group, 1955 mGy; vs non-AI group, 3755 mGy; P = .004), a significant decrease in the fluoroscopy time (AI group, 55.6 minutes; vs non-AI group, 86.9 minutes; P = .007), a decrease in the operative time (AI group, 255 minutes; vs non-AI group, 284 minutes; P = .294), and a significant decrease in contrast use (AI group, 123 mL; vs non-AI group, 199 mL; P < .0001). No differences were found in the 30-day and long-term outcomes. ConclusionsThe results from the present study have demonstrated that the use of AI technology combined with intraoperative imaging can significantly facilitate complex endovascular aneurysm repair by decreasing the operative time, radiation exposure, fluoroscopy time, and contrast use. Overall, evolving technology such as AI has improved radiation safety for both the patient and the entire operating room team.

Incidence of Subdural Catheter Placement During Epidural Procedure Based on Fluoroscopic Imaging

(Reg Anesth Pain Med. 2021;46:538–539) The percentage of failed epidural anesthesia placement due to subdural catheter placement is unknown. Subdural catheter placement is difficult to identify because it can occur despite having a negative test dose and negative aspiration of cerebrospinal fluid. This poses a problem to the patient because subdural placement may not penetrate anterior nerve roots, resulting in continued pain. This study utilized real-time fluoroscopic imaging in an effort to determine the incidence of subdural catheter placement during epidural anesthesia.

Abstract TMP61: Telerobotic Neurovascular Interventions With Magnetic Manipulation

Background: Advances in robotic technology have been adopted in various subspecialties of both open and minimally invasive surgery, offering benefits such as enhanced surgical precision and accuracy with reduced efforts and fatigue. Despite the advantages, robotic applications to endovascular neurosurgery have remained largely unexplored due to technical challenges such as the miniaturization of robotic devices that can navigate the complex and tortuous cerebral vasculature. Although some commercial robotic systems enable precise manipulation of conventional guidewires for coronary and peripheral vascular interventions, they remain unsuited for neurovascular applications due to the considerably smaller and more tortuous anatomy of cerebral arteries. Methods: We present a teleoperated robotic system designed for neurovascular interventions based on magnetic steering and navigation. Our system consists of a magnetically controlled guidewire, a robot arm with a permanent magnet attached to its end-effector for steering control of the guidewire, a set of motorized linear drives to advance or retract the guidewire and a microcatheter, and a remote-control console to operate the system under feedback from real-time fluoroscopic imaging and visualization. Results: With a life-sized neurovascular phantom, we demonstrate the navigational capability to reach several branches of circle of Willis and distal cerebral vasculature with the magnetic guidewire under teleoperation of the system. We further demonstrate telerobotically-assisted therapeutic procedures including coil embolization and clot retrieval thrombectomy for intracranial aneurysms and ischemic stroke, respectively. Conclusion: Our telerobotic neurointerventional platform could enable safer and quicker access to hard-to-reach lesions, significantly reduce operative time and perioperative risk by reducing intravascular manipulation, minimize the radiation exposure to interventionalists, and open the possibility of remote procedural services to address challenges in current stroke systems of care. Note: Animal testing will be performed in Q3 2021 and the results will be presented at ISC.

Efficiency and Efficacy of Real-Time Fluoroscopic Image-Guided Percutaneous Gasserian Glycerol Rhizotomy (PGGR), for Intractable Cases of Trigeminal Neuralgia.

To evaluate the ease, efficiency, effectiveness, and associated complications of the technique of percutaneous Gasserian glycerol rhizotomy (PGGR) under real-time fluoroscopic image guidance, for management of severe and refractory cases of primary trigeminal neuralgia, in medical compromised patients. To also assess the long-term efficacy and the necessity, if any, for repeat procedures to salvage recurrences. In a prospective study conducted at a single institution over a period of three years, 25 cases of Idiopathic Trigeminal Neuralgia refractory to conservative modalities of treatment including medication were managed with PGGR under real-time fluoroscopic image guidance. All the 25 patients included in this study were known surgical risks for relatively invasive treatment procedures, owing to factors such as advanced age and/or presence of co-morbidities. In order to minimize the risks related to the conventional techniques of Trigeminal root rhizotomy based on cutaneous landmarks alone, and to eliminate the need for frequent repositioning of the needle/cannula, we adopted a technique of real-time fluoroscopic image-guided negotiation of a 22 gauge (0.7mm dia), 10-cm-long spinal nerve block needle through the foramen ovale, to reach the trigeminal cistern within the Meckel's cave. The efficiency of the technique was assessed in terms of time taken, effort, and ease in performing it. Associated intra- and post-procedural complications were recorded. The immediate and long-term effectiveness of the procedure was evaluated by analysing the degree and duration of pain control achieved, time to recurrence, and the necessity for repeat procedures. There were nil intra- or post-procedural complications encountered, and no failures associated with this procedure. Real-time fluoroscopic imaging enabled easy, quick, and successful negotiation of the nerve-block needle through the Foramen Ovale, so as to reach the Trigeminal cistern within the Meckel's cave, within 11min on an average. An immediate and long lasting post-procedural pain relief was achieved in all the patients. During the follow-up period of 36months, recurrence of pain was observed in six cases, the mean timing of the recurrence being 26months or more. Five of these cases were manageable with medication alone, and only one required a repeat procedure. These results indicate that PGGR under real-time fluoroscopic image guidance is a safe, simple, time-efficient, convenient, efficacious, reliable, and minimally invasive means of treating refractory and intractable cases of trigeminal neuralgia.

Percutaneous Trans-Hepatic Embolization of an Iatrogenic Extra-Hepatic Pseudoaneurysm of the Right Hepatic Artery in a Patient With Previous Occlusion of the Proper Hepatic Artery: An Endovascular Procedure to Avoid a Difficult Surgical Repair

We report a case of successful percutaneous transhepatic, embolization of an iatrogenic extra-hepatic pseudoaneurysm (PsA) of the right hepatic artery (RHA) under combined fluoroscopic and ultrasonographic guidance. A 73-year-old man underwent percutaneous transhepatic biliary drainage placement in another hospital, complicated by haemobilia and development of a RHA PsA. Endovascular embolization was attempted, resulting in coil embolization of the proper hepatic artery, and persistence of the PsA. At this point, the patient was referred to our hospital. Computed tomography and direct angiography confirmed the iatrogenic extra-hepatic PsA of the RHA, refilled by small collaterals from the accessory left hepatic artery (LHA) and coil occlusion of the proper hepatic artery. Attempted selective catheterization of these vessels was unsuccessful due to the tortuosity and very small caliber of the intra-hepatic collaterals, the latter precluding endovascular treatment of the PsA. Percutaneous trans-hepatic combined fluoroscopic and ultrasound-guided embolization of the PsA was performed with Lipiodol® and cyanoacrylate-based glue (Glubran®2). Real time fluoroscopic images and computed tomography confirmed complete occlusion of the pseudoaneurysm. Surgical repair, although feasible, was considered at high risk. In our patient, we decided to perform a percutaneous trans-hepatic combined fluoroscopic and ultrasound-guided embolization of the PsA using a mix of Lipiodol® and Glubran®2 because of the fast polymerization time of the glue allowing the complete occlusion of the PsA in few seconds, thus eliminating the risk of coil migration, reducing the risk of PsA rupture and avoid a difficult surgical repair.

P1161Pre-implantation MRI identification of late-mechanical activation segments with dedicated software platform to guide the cardiac resynchronization therapy

Abstract Introduction The Cardiac Resynchronization Therapy (CRT) is a well-established treatment for patients with electromechanical dyssynchrony of the left ventricle (LV) and drug-refractory heart failure (HF). Despite technical improvement and accurate selection, still a 30% of implanted patients are non-responder to CRT. Suboptimal LV lead placement in areas of early mechanical activation is one of the major reasons of poor response rate. Objectives To evaluate and test the performance of an integrated and highly automated software platform used for processing and analyzing standard preoperative Cardiac Magnetic Resonance (CMR) data and overlaying this data with real-time fluoroscopic images. Methods Using a dedicated software for post-hoc analysis of CMR data, segments of late mechanical activation (LMA) in the 16 segments model before CRT implant were identified and used as target segments for the coronary sinus (CS) lead implant. All patients underwent CRT implantation after performing a standard CMR. A real time match between the selected segments and the fluoroscopic images (AP and at least one LAO or RAO projection with ≥30° angle difference) was obtained for each case during the procedure (Figure 1). In two patients who underwent to Cardiac-CT (CCT), a postprocessing analysis with a dedicated software was performed to obtain a 3D CS anatomy model before implant, which was used as a guide for the CS catheter during procedure. The 3D CS model was merged with the 3D-LV Model. Patients were enrolled during a period from 30th November 2017 to 30th July 2019 and where divided in two groups, Group A if the CS lead was placed in the target segment and Group B if the lead didn´t reach the target. Results Considering all patients (21 patients, 24% females and 76% males, age 69 ± 10.7 years; NYHA class: 3 ± 0.4; 62% with Late-gadolinium-enhancement and 38% without Late-gadolinium-enhancement; EF 30 ± 5.6%; QRS 174.9 ± 29 ms; 81% with left bundle block), in 57% the placement of the CS lead to the pre-procedurally defined LMA target segments and an effective pacing was obtained. In the Group A we documented a trend in shorter paced QRS duration (QRS pre 173.2 ± 31.9, QRS post 138.3 ± 26) and a trend in EF increase during short-term follow up (EF from 29.4 ± 3% to 41.9 ± 3%) compared with Group B (QRS pre 177.2 ± 26, QRS post 147 ± 33.6 and EF from 36 ± 7.5% to 41 ± 5%). Conclusions The pre-implantation planning of CRT implant, in patients candidate to a resynchronization treatment, focusing on identification of the LMA segments, is an emerging tool. Real-time fluoroscopic images and CMR-guided LV CS lead placement provide preferential sites for lead placement and preliminary data demonstrated a trend in increase of treatment response. A successful implant in the preselected target segment was achieved in 57% of cases in our study and a trend in a concomitant better electrical response of resynchronization was observed. Abstract Figure 1. CS lead in target segments

Endovascular Treatment of Cavernous Sinus Dural Arteriovenous Fistulas via Direct Transorbital Puncture Using Cone-Beam Computed Tomography Image Guidance: Report of 3 Cases

Certain cavernous sinus (CS) dural arteriovenous fistulas (DAVFs) are difficult to access through transarterial or transvenous routes and may necessitate access through direct transorbital puncture of the superior ophthalmic vein (SOV) or the CS. However, to be successful, the accurate design of the puncture route and guidance are crucial. This study aimed to report our preliminary clinical experience using cone-beam computed tomography (CT) with real-time fluoroscopic overlays for image guidance during transorbital needle puncture. Between December 2017 and July 2018, 3 patients with CS DAVFs were treated via a transorbital puncture to establish access to the CS under the guidance of XperGuide planning software either via direct CS puncture or through the SOV. The guidance trajectory was superimposed onto the real-time fluoroscopic image during needle puncture. Once access was established, the CS DAVFs were treated with a combination of liquid embolic materials and coils. Image guidance aided to avoid at-risk structures and treatment resulted in all cases in complete obliteration of the CS DAVFs as verified by control angiography without peri- or postprocedural complications. Endovascular embolization of CS DAVFs via direct transorbital puncture aided by image guidance provided an alternative option when more conventional approaches are deemed not possible.

A Dual-layer Detector for Simultaneous Fluoroscopic and Nuclear Imaging.

Purpose To develop and evaluate a dual-layer detector capable of acquiring intrinsically registered real-time fluoroscopic and nuclear images in the interventional radiology suite. Materials and Methods The dual-layer detector consists of an x-ray flat panel detector placed in front of a γ camera with cone beam collimator focused at the x-ray focal spot. This design relies on the x-ray detector absorbing the majority of the x-rays while it is more transparent to the higher energy γ photons. A prototype was built and dynamic phantom images were acquired. In addition, spatial resolution and system sensitivity (evaluated as counts detected within the energy window per second per megabecquerel) were measured with the prototype. Monte Carlo simulations for an improved system with varying flat panel compositions were performed to assess potential spatial resolution and system sensitivity. Results Experiments with the dual-layer detector prototype showed that spatial resolution of the nuclear images was unaffected by the addition of the flat panel (full width at half maximum, 13.6 mm at 15 cm from the collimator surface). However, addition of the flat panel lowered system sensitivity by 45%-60% because of the nonoptimized transmission of the flat panel. Simulations showed that an attenuation of 27%-35% of the γ rays in the flat panel could be achieved by decreasing the crystal thickness and housing attenuation of the flat panel. Conclusion A dual-layer detector was capable of acquiring real-time intrinsically registered hybrid images, which could aid interventional procedures involving radionuclides. Published under a CC BY-NC-ND 4.0 license. Online supplemental material is available for this article.

Registration of angiographic image on real-time fluoroscopic image for image-guided percutaneous coronary intervention.

In percutaneous coronary intervention (PCI), cardiologists must study two different X-ray image sources: a fluoroscopic image and an angiogram. Manipulating a guidewire while alternately monitoring the two separate images on separate screens requires a deep understanding of the anatomy of coronary vessels and substantial training. We propose 2D/2D spatiotemporal image registration of the two images in a single image in order to provide cardiologists with enhanced visual guidance in PCI. The proposed 2D/2D spatiotemporal registration method uses a cross-correlation of two ECG series in each image to temporally synchronize two separate images and register an angiographic image onto the fluoroscopic image. A guidewire centerline is then extracted from the fluoroscopic image in real time, and the alignment of the centerline with vessel outlines of the chosen angiographic image is optimized using the iterative closest point algorithm for spatial registration. A proof-of-concept evaluation with a phantom coronary vessel model with engineering students showed an error reduction rate greater than 74% on wrong insertion to nontarget branches compared to the non-registration method and more than 47% reduction in the task completion time in performing guidewire manipulation for very difficult tasks. Evaluation with a small number of experienced doctors shows a potentially significant reduction in both task completion time and error rate for difficult tasks. The total registration time with real procedure X-ray (angiographic and fluoroscopic) images takes[Formula: see text]60ms, which is within the fluoroscopic image acquisition rate of 15Hz. By providing cardiologists with better visual guidance in PCI, the proposed spatiotemporal image registration method is shown to be useful in advancing the guidewire to the coronary vessel branches, especially those difficult to insert into.

Multiple breath-hold segmented volumetric modulated arc therapy under real-time fluoroscopic image guidance with implanted fiducial markers: preliminary clinical experience

A technique for multiple breath-hold segmented volumetric modulated arc therapy (VMAT) has been proposed under real-time fluoroscopic image guidance with implanted fiducial markers. Fiducial markers were embedded as close as possible to a tumour and the patient was asked to breathe in slowly under fluoroscopy. Immediately after the marker positions on the fluoroscopic image moved inside the planned marker contours transferred from a digitally reconstructed radiographic image at each gantry start angle, the patient was asked to hold their breath and a segmented VMAT beam was delivered. During beam delivery, the breath-hold status was continuously monitored by viewing a pointer in a breath monitoring system, Abches (Apex Medical, Tokyo, Japan), with the aid of a video camera installed in the treatment room. As long as the pointer stayed still, the segmented VMAT delivery continued for a preset period of 15–30 s, depending on the breath-hold capability of each patient. As soon as each segmented delivery was completed, the beam interrupt button was pushed; subsequently, the patient was asked to breathe freely. Because the preset breath-hold period was determined in order for each patient to hold their breath without fail, an intermediate beam interrupt due to breath-hold failure during the segmented beam delivery was not observed. This procedure was repeated until all the segmented VMAT beams were delivered. A case of pancreatic cancer is reported here as a preliminary study. The proposed technique may be clinically advantageous for treating tumours that move with respiration, including pancreatic cancer, lung tumour and other abdominal cancers.

Multimodality calibration for simultaneous fluoroscopic and nuclear imaging.

BackgroundSimultaneous real-time fluoroscopic and nuclear imaging could benefit image-guided (oncological) procedures. To this end, a hybrid modality is currently being developed by our group, by combining a c-arm with a gamma camera and a four-pinhole collimator. Accurate determination of the system parameters that describe the position of the x-ray tube, x-ray detector, gamma camera, and collimators is crucial to optimize image quality. The purpose of this study was to develop a calibration method that estimates the system parameters used for reconstruction.A multimodality phantom consisting of five point sources was created. First, nuclear and fluoroscopic images of the phantom were acquired at several distances from the image intensifier. The system parameters were acquired using physical measurement, and multimodality images of the phantom were reconstructed. The resolution and co-registration error of the point sources were determined as a measure of image quality. Next, the system parameters were estimated using a calibration method, which adjusted the parameters in the reconstruction algorithm, until the resolution and co-registration were optimized. For evaluation, multimodality images of a second set of phantom acquisitions were reconstructed using calibrated parameter sets. Subsequently, the resolution and co-registration error of the point sources were determined as a measure of image quality. This procedure was performed five times for different noise simulations. In addition, simultaneously acquired fluoroscopic and nuclear images of two moving syringes were obtained with parameter sets from before and after calibration.ResultsThe mean FWHM was significantly lower after calibration than before calibration for 21 out of 25 point sources. The mean co-registration error was significantly lower after calibration than before calibration for all point sources. The simultaneously acquired fluoroscopic and nuclear images showed improved co-registration after calibration as compared with before calibration.ConclusionsA calibration method was presented that improves the resolution and co-registration of simultaneously acquired hybrid fluoroscopic and nuclear images by estimating the geometric parameter set as compared with a parameter set acquired by direct physical measurement.Electronic supplementary materialThe online version of this article (doi:10.1186/s40658-016-0156-1) contains supplementary material, which is available to authorized users.

Image fusion-guided portal vein puncture during transjugular intrahepatic portosystemic shunt placement.

The purpose of this study was to assess the feasibility and utility of image fusion (Easy-TIPS) obtained from pre-procedure CT angiography and per-procedure real-time fluoroscopy for portal vein puncture during transjugular intrahepatic portosystemic shunt (TIPS) placement. Eighteen patients (15 men, 3 women) with a mean age of 63 years (range: 48-81 years; median age, 65 years) were included in the study. All patients underwent TIPS placement by two groups of radiologists (one group with radiologists of an experience<3 years and one with an experience≥3 years) using fusion imaging obtained from three-dimensional computed tomography angiography of the portal vein and real-time fluoroscopic images of the portal vein. Image fusion was used to guide the portal vein puncture during TIPS placement. At the end of the procedure, the interventional radiologists evaluated the utility of fusion imaging for portal vein puncture during TIPS placement. Mismatch between three-dimensional computed tomography angiography and real-time fluoroscopic images of the portal vein on image fusion was quantitatively analyzed. Posttreatment CT time, number of the puncture attempts, total radiation exposure and radiation from the retrograde portography were also recorded. Image fusion was considered useful for portal vein puncture in 13/18 TIPS procedures (72%). The mean posttreatment time to obtain fusion images was 16.4minutes. 3D volume rendered CT angiography images was strictly superimposed on direct portography in 10/18 procedures (56%). The mismatch mean value was 0.69cm in height and 0.28cm laterally. A mean number of 4.6 portal vein puncture attempts was made. Eight patients required less than three attempts. The mean radiation dose from retrograde portography was 421.2dGy.cm2, corresponding to a mean additional exposure of 19%. Fusion imaging resulting from image fusion from pre-procedural CT angiography is feasible, safe and makes portal puncture easier during TIPS placement.

Early experience with X-ray magnetic resonance fusion for low-flow vascular malformations in the pediatric interventional radiology suite

This technical innovation describes our experience using an X-ray magnetic resonance fusion (XMRF) software program to overlay 3-D MR images on real-time fluoroscopic images during sclerotherapy procedures for vascular malformations at a large pediatric institution. Five cases have been selected to illustrate the application and various clinical utilities of XMRF during sclerotherapy procedures as well as the technical limitations of this technique. The cases demonstrate how to use XMRF in the interventional suite to derive additional information to improve therapeutic confidence with regards to the extent of lesion filling and to guide clinical management in terms of intraprocedural interventional measures.

Toward Simultaneous Real-Time Fluoroscopic and Nuclear Imaging in the Intervention Room.

To investigate the technical feasibility of hybrid simultaneous fluoroscopic and nuclear imaging. An x-ray tube, an x-ray detector, and a gamma camera were positioned in one line, enabling imaging of the same field of view. Since a straightforward combination of these elements would block the lines of view, a gamma camera setup was developed to be able to view around the x-ray tube. A prototype was built by using a mobile C-arm and a gamma camera with a four-pinhole collimator. By using the prototype, test images were acquired and sensitivity, resolution, and coregistration error were analyzed. Nuclear images (two frames per second) were acquired simultaneously with fluoroscopic images. Depending on the distance from point source to detector, the system resolution was 1.5-1.9-cm full width at half maximum, the sensitivity was (0.6-1.5) × 10(-5) counts per decay, and the coregistration error was -0.13 to 0.15 cm. With good spatial and temporal alignment of both modalities throughout the field of view, fluoroscopic images can be shown in grayscale and corresponding nuclear images in color overlay. Measurements obtained with the hybrid imaging prototype device that combines simultaneous fluoroscopic and nuclear imaging of the same field of view have demonstrated the feasibility of real-time simultaneous hybrid imaging in the intervention room.

High Yield of Bronchoscopic Transparenchymal Nodule Access Real-Time Image-Guided Sampling in a Novel Model of Small Pulmonary Nodules in Canines

Bronchoscopic transparenchymal nodule access (BTPNA) is a novel approach to accessing pulmonary nodules. This real-time, image-guided approach was evaluated for safety, accuracy, and yield in the healthy canine model. A novel, inorganic model of subcentimeter pulmonary nodules was developed, consisting of 0.25-cc aliquots of calcium hydroxylapatite (Radiesse) implanted via transbronchial access in airways seven generations beyond the main bronchi to represent targets for evaluation of accuracy and yield. Thoracic CT scans were acquired for each subject, and from these CT scans LungPoint Virtual Bronchoscopic Navigation software provided guidance to the region of interest. Novel transparenchymal nodule access software algorithms automatically generated point-of-entry recommendations, registered CT images, and real-time fluoroscopic images and overlaid guidance onto live bronchoscopic and fluoroscopic video to achieve a vessel-free, straight-line path from a central airway through parenchymal tissue for access to peripheral lesions. In a nine-canine cohort, the BTPNA procedure was performed to sample 31 implanted Radiesse targets, implanted to simulate pulmonary nodules, via biopsy forceps through a specially designed sheath. The mean length of the 31 tunnels was 35 mm (20.5-50.3-mm range). Mean tunnel creation time was 16:52 min, and diagnostic yield was 90.3% (28 of 31). No significant adverse events were noted in the status of any of the canine subjects post BTPNA, with no pneumothoraces and minimal bleeding (all bleeding events < 2 mL in volume). These canine studies demonstrate that BTPNA has the potential to achieve the high yield of transthoracic needle aspiration with the low complication profile associated with traditional bronchoscopy. These results merit further study in humans.

Does inter-vertebral range of motion increase after spinal manipulation? A prospective cohort study

281 Branney and Breen set out to examine hypo-mobility detected by palpation as a basis for manipulative treatment of patients suffering neck pain, and the impact of manipulative treatment on IV-RoM and patient reported outcomes. In order to achieve this they designed a prospective cohort study of patients with nonspecific neck pain and healthy controls matched for age and gender. A relatively new technology for the objective measurement of IV-RoM was the key outcome measure. Quantitative fluoroscopy (QF) can be used to track and measure vertebral motion by computer analysis of real time fluoroscopic images, in this case recorded at 15 frames per second. Thirty participants suffering from neck pain and 30 asymptomatic participants were recruited. Cervical flexion and extension IV-RoM for spinal segments 1-6 were examined by palpation and recorded. The same motion was then assessed using QF to produce baseline data, and then re-assessed 4 weeks later for all participants. Over the 4 week period the symptomatic participants received up to 12 neck manipulations as part of a chiropractic management plan which focused on HVTs as the primary intervention. Symptomatic participants also completed various self-reported outcomes measures (11-point numerical rating scale for pain, neck disability index, EuroQol EQ5L, and the patient global impression of change) at baseline and 4 week follow-up. The results confirmed the high accuracy and repeatability of QF for the measurement of IV-RoM. There was no difference between the numbers of hypo-mobile segments in symptomatic participants compared to controls, and there was no agreement between palpation and QF in detecting hypo-mobile segments. While overall the neck pain participant’s symptoms improved, there was no correlation between increase in IV-RoM and patient reported outcomes after the course of manipulations. There was a modest correlation between the number of manipulations received and the number of levels at which IV-RoM increased, but it should be noted that almost all the segments at which IV-RoM increased already had normal mobility (measured by QF) before the application of manipulations. In their brief discussion of these results Branney and Breen create a context for their findings by highlighting research which has supported the notion that neck pain and cervical range of motion are intimately linked on a mechanical level, and hint that manipulation has mechanical effects on IV-RoM of importance for the management of neck pain. However, altered spinal motion in neck pain sufferers may of course be due to non-mechanical factors (e.g. fear avoidance). Seen in this light, their results in fact building upon previous studies (see Seffinger et al. for a review) that have helped deconstruct the role that palpated inter-vertebral hypo-mobility plays in the diagnosis and treatment of spinal pain. These results should further encourage clinicians in resisting the urge to manage their patient’s spinal pain based solely on biomechanical and pathoanatomical “findings”. Numerous other neurological and psychosocial factors contribute to a patient’s experience of pain and disability and should not be placed second in line to supposed joint hypo-mobility and other unreliable assessments in justifying and directing the application of manual therapy interventions such as HVT.

Desktop-Based Computer-Assisted Orthopedic Training System for Spinal Surgery

Simulation and surgical training has moved on since its inception during the end of the last century. The trainees are getting more exposed to computers and laboratory training in different subspecialties. More needs to be done in orthopedic simulation in spinal surgery. To develop a training system for pedicle screw fixation and validate its effectiveness in a cohort of junior orthopedic trainees. Fully simulated computer-navigated training system is used to train junior orthopedic trainees perform pedicle screw insertion in the lumbar spine. Real patient computed tomography scans are used to produce the real-time fluoroscopic images of the lumbar spine. The training system was developed to simulate pedicle screw insertion in the lumbar spine. A total of 12 orthopedic senior house officers performed pedicle screw insertion in the lumbar spine before and after the training on training system. The results were assessed based on the scoring system, which included the amount of time taken, accuracy of pedicle screw insertion, and the number of exposures requested to complete the procedure. The result shows a significant improvement in amount of time taken, accuracy of fixation, and the number of exposures after the training on simulator system. This was statistically significant using paired Student t test (p < 0.05). Fully simulated computer-navigated training system is an efficient training tool for young orthopedic trainees. This system can be used to augment training in the operating room, and trainees acquire their skills in the comfort of their study room or in the training room in the hospital. The system has the potential to be used in various other orthopedic procedures for learning of technical skills in a manner aimed at ensuring a smooth escalation in task complexity leading to the better performance of procedures in the operating theater.

PD36-04 RENAL PERCUTANEOUS ACCESS WITH THE URO DYNA-CT

You have accessJournal of UrologyStone Disease: New Technology I1 Apr 2014PD36-04 RENAL PERCUTANEOUS ACCESS WITH THE URO DYNA-CT Fabio Torricelli, Khaled Fareed, Gordon McLennan, Shubha De, and Manoj Monga Fabio TorricelliFabio Torricelli More articles by this author , Khaled FareedKhaled Fareed More articles by this author , Gordon McLennanGordon McLennan More articles by this author , Shubha DeShubha De More articles by this author , and Manoj MongaManoj Monga More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.2441AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Percutaneous nephrolitothomy (PCNL) is the gold standard for surgical management of renal stones >2cm. Renal access may be challenging in cases of complex renal anatomy or large stone burden (i.e. complete staghorn calculi). Herein, we present percutaneous renal access using an Uro Dyna-CT (Siemens Healthcare Solutions, Germany), for high-quality 3-dimensional real-time imaging. METHODS Review of an index patient: 50y/o male presenting with a right partial staghorn and proximal ureteric stone. RESULTS Electing to undergo PCNL, he was referred to radiology for pre-op percutaneous renal access. Two attempts for upper/middle pole NT placement were made (to simultaneously treat lower pole and ureteric stones), however due to the plural reflection and overlying liver a safe puncture tract could not be established. A Uro Dyna-CT was performed by correlating real time fluoroscopic imaging to a simultaneous on-table axial CT scan (Figures 2-3). Delineating a safe window, right middle pole access allowed subsequent PCNL to be performed successfully. CONCLUSIONS In select patients, the Uro Dyna-CT adds simultaneous detailed anatomic imaging to fluoroscopic renal access to improve successful puncture, and reduce potential morbidities. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e902 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Fabio Torricelli More articles by this author Khaled Fareed More articles by this author Gordon McLennan More articles by this author Shubha De More articles by this author Manoj Monga More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Using XperGuide Planning Software to Safely Guide Catheter Access to the Cavernous Sinus via Transorbital Puncture

Many techniques for accessing the cavernous sinus have been described, from a transfemoral venous approach to a direct surgical exposure and cannulation of the superior ophthalmic vein. The cavernous sinus can be accessed safely through direct transorbital puncture and cannulation of a preceding venous confluence with an 18-gauge angiocatheter. This technique is performed under constant fluoroscopy using bony landmarks. The use of XperGuide software allows the operator to obtain an intraprocedural computed tomography and to identify the optimum needle entry point and trajectory to avoid at-risk structures such as the optic nerve in this case. This trajectory is then superimposed onto the real-time fluoroscopic image, and the guidance trajectory is followed during needle insertion. The patient is a 66-year-old woman who spontaneously developed a left-sided cavernous sinus syndrome. She was found to have an indirect carotid cavernous fistula on angiography. Because of tortuosity and occlusion of venous access points to the cavernous sinus, access via transorbital puncture was preferred. The XperGuide system was used to avoid the at-risk structures, and coils were safely deployed within the cavernous sinus after successful cannulation with this guidance system. The patient had complete resolution of her fistula and experienced no complications from the procedure. The XperGuide software guidance system is helpful during direct transorbital puncture of the cavernous sinus because it allows better monitoring of real-time needle location along a safe trajectory selected by the operator to avoid damaging local soft tissue structures.

Pericardium based model fusion of CT and non-contrasted C-arm CT for visual guidance in cardiac interventions.

Minimally invasive transcatheter cardiac interventions are being adopted rapidly to treat a range of cardiovascular diseases. Pre-operative imaging, e.g., computed tomography (CT), plays an important role in surgical planning and simulation of cardiac interventions. Overlaying a 3D cardiac model extracted from pre-operative images onto real-time fluoroscopic images provides valuable visual guidance during the intervention. However, direct 3D to 2D fusion is difficult and may require quite amounts of user interaction. Intra-operative non-contrasted C-arm CT can be used as an intermedium for model fusion. The cardiac model is first warped to C-arm CT and later overlaid onto fluoroscopy. The C-arm CT to fluoroscopy overlay is straightforward since both images are captured on the same machine and the C-arm projection geometry can be directly used for overlay. Though various image registration methods may be used to fuse pre-operative images and C-arm CT, cross-modality image registration is not robust due to the significant difference in image characteristics (contrasted vs. non-contrasted). In this work we propose a model based fusion method using the pericardium to align pre-operative CT to intra-operative C-arm CT. After automatic segmentation of the pericardium in both CT and C-arm CT, the deformation field is estimated and then applied to warp the cardiac model extracted from CT to C-arm CT. The proposed method can be applied to fuse different cardiac models (e.g., chambers, aorta, coronary arteries, and cardiac valves). A feasibility study on aortic root model fusion shows that a reasonable accuracy can be achieved using a generic model (from a different patient), while more accurate results come from a patient-specific model. Intelligently weighted fusion can further improve the accuracy by using all available cardiac models in a pre-collected training set.