Coil Localization Research Articles

Unfolding coil localized errors from an imperfect slice profile using a structured autocalibration matrix: An application to reduce outflow effects in cine bSSFP imaging.

Balanced steady-state free precession (bSSFP) imaging is susceptible to outflow effects where excited spins leaving the slice as part of the blood stream are misprojected back onto the imaging plane. Previous work proposed using slice-encoding steps to localize these outflow effects from corrupting the target slice, at the expense of prolonged scan time. This present study extends this idea by proposing a means of significantly reducing most of the outflowing signal from the imaged slice using a coil localization method that acquires a slice-encoded calibration scan in addition to the 2D data, without being nearly as time-demanding as our previous method. This coil localization method is titled UNfolding Coil Localized Errors from an imperfect slice profile using a Structured Autocalibration Matrix (UNCLE SAM). Retrospective and prospective evaluations were carried out. Both featured a 2D acquisition and a separate slice-encoded calibration of the center in-plane -space lines across all desired slice-encoding steps. Retrospective results featured a slice-by-slice comparison of the slice-encoded images with UNCLE SAM. UNCLE SAM's subtraction from the slice-encoded image was compared with a subtraction from the flow-corrupted 2D image, to demonstrate UNCLE SAM's capability to unfold outflowing spins. UNCLE SAM's comparison with slice encoding showed that UNCLE SAM was able to unfold up to 74% of what slice encoding achieved. Prospective results showed significant reduction in outflow effects with only a marginal increase in scan time from the 2D acquisition. We developed a method that effectively unfolds most outflowing spins from corrupting the target slice and does not require the explicit use of slice-encoding gradients. This development offers a method to reduce most outflow effects from the target slice within a clinically feasible scan duration compared with the fully sampled slice-encoding technique.

Preoperative coil localization for spinal surgery is accurate, safe and effective: a single-centre initial experience.

This is a retrospective, descriptive study of consecutive patients undergoing novel preoperative pushable coil localization for spinal surgery, in order to evaluate its feasibility, safety and accuracy. Consecutive patients who underwent pre-operative coil marking for spinal surgery at our institution from May 2018 to July 2021 were included. Data were collected for coil placement, accuracy, complications and fluoroscopy usage. Patient demographic and relevant perioperative and procedural data were also collected. A total of 34 patients were identified of which 32 (94%) had complete data and imaging at last clinical follow up, with a mean duration of 13.9 months. There were no incorrect level surgeries performed. There were no coil-related complications found in our cohort. Preoperative coil placement is an accurate, safe and well-tolerated method for level localization in spinal surgeries.

Research on coil positioning method and magnetic field orientation strategy of wireless power transfer system

In wireless power transfer (WPT) system, the displacement of the receiver coil may cause the problem of efficiency reduction. For this, this paper presents a coil localization method based on the BP neural network, and studies the strategy of using current phase-shift control to realize power orientation in positioning area. In this paper, the distribution of the array coils is designed as overlap, the relationship between the regional coordinate points and the coil current is studied, and the BP neural network is introduced to establish the coil positioning model. In order to effectively improve the localization accuracy, we propose a partition modeling optimization method based on this model. At the same time, a BP neural network magnetic flux model is established to determine the optimal phase of the array coil current when the magnetic flux in the region is the largest. Simulation and experiments show that the average positioning error of the optimization method in the area of 32.9 cm ×32.9 cm is less than 1 cm.

Electroanatomical mapping of the stomach with simultaneous biomagnetic measurements

Gastric motility is coordinated by bioelectric slow waves (SWs) and dysrhythmic SW activity has been linked with motility disorders. Magnetogastrography (MGG) is the non-invasive measurement of the biomagnetic fields generated by SWs. Dysrhythmia identification using MGG is currently challenging because source models are not well developed and the impact of anatomical variation is not well understood. A novel method for the quantitative spatial co-registration of serosal SW potentials, MGG, and geometric models of anatomical structures was developed and performed on two anesthetized pigs to verify feasibility. Electrode arrays were localized using electromagnetic transmitting coils. Coil localization error for the volume where the stomach is normally located under the sensor array was assessed in a benchtop experiment, and mean error was 4.2±2.3mm and 3.6±3.3° for a coil orientation parallel to the sensor array and 6.2±5.7mm and 4.5±7.0° for a perpendicular coil orientation. Stomach geometries were reconstructed by fitting a generic stomach to up to 19 localization coils, and SW activation maps were mapped onto the reconstructed geometries using the registered positions of 128 electrodes. Normal proximal-to-distal and ectopic SW propagation patterns were recorded from the serosa and compared against the simultaneous MGG measurements. Correlations between the center-of-gravity of normalized MGG and the mean position of SW activity on the serosa were 0.36 and 0.85 for the ectopic and normal propagation patterns along the proximal–distal stomach axis, respectively. This study presents the first feasible method for the spatial co-registration of MGG, serosal SW measurements, and subject-specific anatomy. This is a significant advancement because these data enable the development and validation of novel non-invasive gastric source characterization methods.

Preoperative CT-Guided Coil Localization of Lung Nodule Resection: A Single-Center Experience.

The increased use of computed tomography (CT) for lung cancer screening has led to an increase in the incidence of lung nodules. However, accurately localizing small or deep-seated nodules remains challenging and often requires image-guided techniques. CT-guided coil localization has emerged as a popular method for precise localization. A retrospective analysis was conducted on a cohort of patients who underwent CT-guided coil localization followed by surgical resection of lung nodules at the National University Hospital, Singapore, between 2015 and 2021. The study examined the rates of successful localization, procedural complications, and postoperative length of stay. Descriptive statistics were employed for data analysis. This retrospective study included 55 patients with pulmonary nodules, of whom 76.4% had a history of previous malignancy. A total of 58 nodules were successfully localized using coil placement and distributed across various lung lobes. The average dimensions of the nodules were 8.4 ± 3.2 mm × 10.1 ± 4.0 mm, with an average distance of 10.9 ± 9.0 mm from the pleura. Surgical resection of the coiled nodules resulted in an average resected volume of 91.1 ± 76.0 cm3 and a resection margin of 9.5 ± 7.3 mm. Failed localization occurred in only 3.6% of cases. Procedural complications were observed in 21.8% of patients, including hemothorax, persistent air leaks, pneumothoraces, pleural effusion, pneumonia, and atelectasis, all of which were appropriately managed. The average length of postoperative hospital stay was 6.7 ± 15.9 days. Preoperative CT-guided coil localization is a reliable and safe technique for accurately localizing lung nodules before surgical resection. The high success rate of this approach enables precise intraoperative planning. Despite procedural complications, their manageable nature and the absence of major adverse events highlight the safety of this technique. Incorporating CT-guided coil localization into routine clinical practice can significantly enhance surgical planning, improve patient outcomes, and optimize resource utilization.

Retrosternal parathyromatosis in a patient with prior total parathyroidectomy

Abstract Parathyromatosis is a rare cause of recurrent primary hyperparathyroidism that often follows surgical removal of the parathyroid gland. Foci of parathyromatosis are most commonly found in the neck, mediastinum, and sites of autotransplantation. A 36-year-old male with renal failure and prior parathyroidectomy presented with generalized bone pain, for which laboratory investigations revealed hyperparathyroidism. Preoperative coil localization was utilized followed by thoracoscopy using fluoroscopy for resection of ectopic parathyroid tissue. The specimen was sent to histopathology, which revealed multiple nodules of hypercellular parathyroid tissue, consistent with the diagnosis of parathyromatosis. Parathyromatosis is a rare cause of recurrent hyperparathyroidism, with surgical removal being the only curative option. Follow-up is essential as it can commonly recur.

Stomach Geometry Reconstruction Using Serosal Transmitting Coils and Magnetic Source Localization.

Bioelectric slow waves (SWs) are a key regulator of gastrointestinal motility, and disordered SW activity has been linked to motility disorders. There is currently a lack of practical options for the acquisition of the 3D stomach geometry during research studies when medical imaging is challenging. Accurately recording the geometry of the stomach and co-registering electrode and sensor positions would provide context for in-vivo studies and aid the development of non-invasive methods of gastric SW assessment. A stomach geometry reconstruction method based on the localization of transmitting coils placed on the gastric serosa was developed. The positions and orientations of the coils, which represented boundary points and surface-normal vectors, were estimated using a magnetic source localization algorithm. Coil localization results were then used to generate surface models. The reconstruction method was evaluated against four 3D-printed anatomically realistic human stomach models and applied in a proof of concept in-vivo pig study. Over ten repeated reconstructions, average Hausdorff distance and average surface-normal vector error values were 4.7 ±0.2 mm and 18.7 ±0.7° for the whole stomach, and 3.6 ±0.2 mm and 14.6 ±0.6° for the corpus. Furthermore, mean intra-array localization error was 1.4 ±1.1 mm for the benchtop experiment and 1.7 ±1.6 mm in-vivo. Results demonstrated that the proposed reconstruction method is accurate and feasible. The stomach models generated by this method, when co-registered with electrode and sensor positions, could enable the investigation and validation of novel inverse analysis techniques.

Comparison of the effectiveness of anchoring needles and coils in localizing multiple nodules in the lung

BackgroundRecently, a new type of pulmonary nodule positioning needle has been adopted clinically. We aimed to evaluate the efficacy and safety of a new type of localization needles compared with coils for the simultaneous localization of multiple pulmonary nodules guided by computed tomography (CT) prior to video-assisted thoracoscopic surgery (VATS).Materials and methodsFrom January 2021 to March 2022, 87 pulmonary nodules from 40 patients were localized using the new localization needle. From January 2020 to December 2020, 68 pulmonary nodules in 31 patients were localized using coils. The relative outcomes were compared.ResultsThe success rate of pulmonary nodule localization in the needle group was 97.7% while that in the coil group was 98.5%. In the needle group, the time needed to locate the first nodule was significantly shorter than in the coil group (10.9 min vs. 17.2 min, P = 0.001). Moreover, the time needed per patient was also significantly shorter for the needle group compared with the coil group (23.7 min vs. 30 min, P = 0.017). The incidence of pneumothorax in the needle group was 25.0% vs. 12.9% in the coil group (P = 0.204). The rate of pulmonary hemorrhage in the needle group was 40.0% vs. 32.3% in the coil group (P = 0.502). The success rate of VATS wedge resection was 100% in both groups.ConclusionBoth disposable pulmonary nodule localization needles and coils are safe and effective for CT-guided localization of multiple pulmonary nodules of the same stage prior to VATS. However, the use of needles is time-saving compared with the use of coils. The coil localization may exhibit better safety than needle localization.

Preoperative computed tomography-guided localization for multiple pulmonary nodules: comparison of methylene blue and coil

BackgroundPreoperative computed tomography (CT)-guided localization has been used to guide the video-assisted thoracoscopic surgery (VATS) sublobar (wedge or segmental) resection for pulmonary nodules (PNs). We aimed to assess the relative efficacy and safety of CT-guided methylene blue (MB)- and coil-based approaches to the preoperative localization of multiple PNs (MPNs).MethodsBetween January 2015 and December 2020, 31 total cases suffering from MPNs at our hospital underwent CT-guided localization and subsequent VATS resection in our hospital, of whom 15 and 16 respectively underwent MB localization (MBL) and coil localization (CL). The clinical effectiveness and complication rates were compared between 2 groups.ResultsThe PN- and patient-based technical success rates in the MBL group were both 100%, whereas in the CL group they were 97.2% (35/36) and 93.8% (15/16), respectively, with no substantial discrepancies between groups. Patients in the MBL group illustrated a substantially shorter CT-guided localization duration compared with the CL group (18 min vs. 29.5 min, P < 0.001). Pneumothorax rates (P = 1.000) and lung hemorrhage (P = 1.000) were comparable in both groups. In the MBL and CL groups, the median interval between localization and VATS was 1 h and 15.5 h, respectively (P < 0.001). One-stage VATS sublobar resection of the target nodules was successfully performed in all patients from both groups.ConclusionBoth CT-guided MBL and CL can be readily and safely utilized for preoperative localization in individuals who had MPNs, with MBL being correlated with a shorter localization duration compared with CL.

Abstract No. 94 Utility of CT-guided coil localization of lung nodules before thoracoscopic surgical resection: a single institution review

To evaluate the utility of pneumothorax creation and chest tube insertion before CT-guided coil localization of non-palpable lung nodules prior to robotic or video-assisted thoracoscopic surgery (RATS or VATS) in terms of the rate of technical success, conversion to completion lobectomy and recurrence rate for malignant lesions

Comparison between coil and hook-wire localization before video-assisted thoracoscopic surgery for lung nodules: a systematic review and meta-analysis.

IntroductionBoth coil and hook-wire localization techniques are commonly employed prior to video-assisted thoracic surgery (VATS) resection in patients with lung nodules (LNs), but the relative advantages of each remain uncertain.AimThis meta-analysis was performed to explore the relative safety and efficacy of coil localization (CL) and hook-wire localization (HWL) for patients with LNs.Material and methodsThe PubMed, Embase, Cochrane Library, Wanfang, and CINK databases were searched to identify relevant studies published as of February 2022, after which pooled analyses of study outcomes were conducted.ResultsIn total, 8 studies met the inclusion criteria for the present meta-analysis. Successful localization rates were higher for the CL group relative to the HWL group (p = 0.0001). The CL group additionally exhibited significantly lower pooled total complication, pneumothorax, and lung hemorrhage rates relative to the HWL group (p = 0.01, p = 0.0001, p = 0.0009). Pooled duration of localization, VATS procedure duration, and wedge resection duration values were comparable in both groups (p = 0.69, p = 0.16, p = 0.76), as were chest pain scores (p = 0.06). When specifically analyzing the subset of patients with ground-glass LNs, pooled pneumothorax rates were significantly lower in the CL group relative to the HWL group (p = 0.03). Significant publication bias was detected with respect to rates of lung hemorrhage (Egger test, p = 0.029), but was not evident for other analyzed variables.ConclusionsThese results suggest that the coil-based localization of LNs before VATS resection is safer and more effective than hook-wire localization.

Coil localization assisted wedge resection for pulmonary nodules in patients with malignant history.

We describe the clinical efficacy of coil localization (CL) assisted video-assisted thoracoscopic surgery (VATS) wedge resection (WR) for pulmonary nodules (PNs) in patients having a history of malignancy.In a total of 16 patients having PNs and malignant history, treatment was carried out using computed tomography (CT)-guided CL and subsequent VATS-guided WR procedures from November 2015 to December 2019. Technical success of CL, WR, and long-term outcomes was analyzed.A total of 21 PNs were localized (1.3 PNs per patient). A 100% technical success rate was achieved in this study for CT-guided CL. Each PN was localized with 1 coil. Two and 2 patients experienced pneumothorax and hemoptysis, respectively. VATS-guided WR also achieved a 100% technical success rate. Additional lobectomy was performed in 2 patients due to the invasive adenocarcinoma. The final diagnoses of these 21 PNs were adenocarcinoma (T1N0M0, n = 8), adenocarcinoma in situ (n = 2), pre-cancerosis (n = 1), metastasis (n = 2), and benign (n = 8). All patients underwent CT follow-up for 6 to 48 months. All patients were alive during the follow-up. The cumulative 6-, 12, and 24-month disease-free survival rates were 100%, 92.9%, and 47.3%, respectively. The median disease-free survival was 27.9 months.Pre-operative CT-guided CL can be safely and conveniently used to facilitate a high success rate of VATS-guided WR for PNs in patients with a malignant history. Among the PNs in patients with malignant history, primary lung cancer also occupied approximately half of the PNs.

Coil-Localized Laparoscopic-Assisted Resection of Symptomatic Gastrointestinal Vascular Malformations in Children and Young Adults.

To describe a technique of intentional preoperative coil localization of symptomatic pediatric GI vascular malformations by pediatric interventional radiology to facilitate fluoroscopically assisted laparoscopic resection. We searched the electronic privacy information center and picture archive and communication system in our center and found 3 cases. The electronic privacy information center and picture archive and communication system databases were the sources for retrieval of demographic, medical, radiological, and procedural information in all 3 cases. After many nondiagnostic investigations in all 3 patients, a GI vascular malformation as a cause of GI bleeding was diagnosed with computed tomography angiography/magnetic resonance angiography and catheter angiography. A preoperative 0.018-inch Hilal coil was placed as close as possible to the vascular malformation during super selective angiography. Laparoscopic surgery was performed within 24 hours of coil placement. In all cases, histology confirmed the resected bowel lesions to be vascular malformations. Intentional endovascular coil localization has the potential to increase the precision of lesion localization and may reduce laparoscopic operative time, when guided by the coil position.

Solving Inverse Problem in Magnetocardiography by Pattern Search Method

In this paper, a novel way of choosing the initial estimates for solving magnetocardiographic inverse problems using the pattern search method is reported. As opposed to the conventional choice of pseudo random numbers, the co-ordinates of the maximum spatial gradient of magnetic fields across sensor locations were used as initial estimates for pattern search method with the help of current density maps. The proposed method has been extensively validated by computer simulation and test coil localization before applying to real magnetocardiogram of a few healthy subjects and those with a known conduction anomaly and ischemic heart disease.

Preoperative computed tomographic-guided percutaneous coil localization of pulmonary nodules: 184 Cases in Single-center.

The aim of this study was to evaluate the feasibility, accuracy, and safety of computed tomographic (CT)-guided coil localization before video-assisted thoracoscopic surgery. One hundred and eighty-four consecutive patients with 200 pulmonary nodules who underwent CT-guided percutaneous coil localization before thoracoscopic surgery were retrospectively analyzed in this study. Success rate for localization, complication rates, CT findings, and pathological results of the lesions, as well as the data related to surgery were all recorded and analyzed. All 184 patients with 200 lesions completed localization and resection. The success rate of the coil localization on lesion baseline was 99.0% (198/200) and 98.9% (182/184) on patient baseline. The number of wedge resection, segmental resection, and lobectomy were 179 (89.5%), 19 (9.5%), and 2 (1.0%), respectively. The malignancy rates in a lesion-based analysis were 83.5% (91.1% in ground-glass nodules, 91.4% in part-solid nodules, and 37.9% in solid nodules). No serious complications occurred in all localization procedures. Preoperative CT-guided percutaneous coil localization is a safe and effective method to facilitate high success rates for both wedge and segmental resection for peripheral pulmonary nodules.

Trans-scapular approach coil localization for scapular-blocked pulmonary nodules: a retrospective study

BackgroundPreoperative computed tomography (CT)-guided coil localization (CL) is commonly used to facilitate video-assisted thoracoscopic surgery (VATS)-guided diagnostic wedge resection (WR) of pulmonary nodules (PNs). When a scapular-blocked PN (SBPN) is localized, the trans-scapular CL (TSCL) is commonly performed. In this study, we investigated the safety, feasibility, and clinical efficacy of preoperative CT-guided TSCL for SBPNs.Materials and methodsFrom January 2014 to September 2020, a total of 152 patients with PNs underwent CT-guided CL prior to VATS-guided WR. Of these patients, 14 had SBPNs and underwent the TSCL procedure.ResultsA total of 14 SBPNs were localized in the 14 patients. The mean diameter of the 14 SBPNs was 7.4 ± 2.4 mm. The technical success rate of the scapula puncture was 100%. No complications occurred near the scapula. The technical success rate of CL was 92.9%. One coil dropped off when performing the VATS procedure. The mean duration of the TSCL was 14.2 ± 2.7 min. Two patients (14.3%) developed asymptomatic pneumothorax after TSCL. The technical success rate of VATS-guided WR was 92.9%. The patient who experienced technical failure of TSCL directly underwent lobectomy. The mean duration of the VATS was 90.0 ± 42.4 min and the mean blood loss was 62.9 ± 37.2 ml. The final diagnoses of the 14 SBPNs included invasive adenocarcinoma (n = 4), adenocarcinoma in situ (n = 9), and benign disease (n = 1).ConclusionsPreoperative CT-guided TSCL is a safe and simple procedure that can facilitate high success rates of VATS-guided WR of SBPNs.

Computed tomography-guided trans-pulmonary-hepatic approach coil localization for pulmonary nodules near the right lung base.

IntroductionVideo-assisted thoracoscopic surgery (VATS)-guided diagnostic wedge resection (WR) is frequently used for removal of pulmonary nodules (PNs). Preoperative computed tomography (CT)-guided coil localization (CL) is often used for guidance.AimTo evaluate the feasibility, safety, and effectiveness of CT-guided trans-pulmonary-hepatic approach CL of PNs near the right lung base.Material and methodsConsecutive patients with PNs who underwent CT-guided CL followed by VATS-guided WR at our center from January 2018 to December 2020 were analyzed.ResultsOne hundred and twenty-two patients with PNs underwent CT-guided CL followed by VATS-guided WR at our center. Of them, 5 (4.1%) patients had PNs near the right lung base and underwent the CT-guided trans-pulmonary-hepatic approach CL procedures. The technical success rate of CL was 100%. The VATS-guided WR was 100% successful. No patient required thoracotomy.ConclusionsCT-guided trans-pulmonary-hepatic approach CL for PNs located near the right lung base is technically feasible.

Preoperative computed tomography-guided coil localization of sub-centimeter lung nodules.

IntroductionLung nodules (LNs) are often identified in at-risk patients via low-dose computed tomography (CT) approaches. Sub-centimeter (≤ 1 cm) LNs (SCLNs) are particularly difficult for surgeons and pathologists to accurately treat and diagnose.AimTo evaluate the clinical efficacy of preoperative CT-guided coil localization for SCLNs.Material and methodsBetween January 2015 and December 2019, consecutive patients at our hospital with SCLNs underwent CT-guided coil localization followed by video-assisted thoracoscopic surgery (VATS). We then assessed rates of technical success corresponding to the localization and VATS-guided wedge resection procedures and measured rates of localization-related complications.ResultsIn total, 52 patients were analyzed in this study, with 66 total SCLNs being localized with one coil each. CT-guided coil localization achieved a 93.9% (62/66) technical success rate, and a mean duration of 15.2 ±4.5 minutes. Following coil localization, 6 (11.5%) patients experienced pneumothorax and 4 (7.7%) patients suffered hemoptysis, with 1 patient requiring the insertion of a chest tube to alleviate pneumothorax. VATS-guided wedge resection was associated with a 100% technical success rate, and no patients needed to undergo conversion to thoracotomy. One-stage VATS-guided wedge resection was conducted in the 12 patients with multiple SCLNs. The mean VATS duration was 128.9 ±66.7 minutes, and mean blood loss associated with this procedure was 83.0 ±67.7 ml.ConclusionsPreoperative CT-guided coil localization can safely and effectively achieve high rates of success when conducting the diagnostic VATS wedge resection of SCLNs.

Computed tomography-guided simultaneous coil localization of multiple pulmonary nodules before video-assisted thoracoscopic surgery.

IntroductionCurrently, different methods and materials are used to localize pulmonary nodules (PNs) but most are used only to locate a single pulmonary nodule (PN).AimTo evaluate the feasibility and safety of simultaneously localizing multiple PNs with a coil under computed tomography (CT) guidance before video-assisted thoracoscopic surgery (VATS).Material and methodsA total of 166 patients underwent VATS preoperative-assisted localization of pulmonary nodules in our hospital in the period from January 2, 2020 to July 7, 2020, namely 40 patients in the multiple-PN-simultaneous-localization group (A) and 126 patients in the single-PN-localization group (B). We compared the epidemiology, localization procedure, and complications between the two groups.ResultsThe technical success rates in group A and Group B were 96.5% and 97.6%, respectively, with no statistical difference (p = 0.623). In group A, the success rate of the first nodule localization was 100%, and the subsequent nodule localization success rate was 93.3%; 3 patients had one nodule localization failure owing to pneumothorax after the first nodule localization. The number of pleural punctures was higher in group A than in group B (p < 0.001), and the localization procedure time was longer than in group B (p < 0.001). Regarding complications, the pneumothorax rate in group A was higher than that in group B (p < 0.001), and the bleeding rate was higher than that in group B (p < 0.001). However, pneumothorax and bleeding in group A did not require special treatment.ConclusionsThe incidence of pneumothorax and pulmonary hemorrhage with simultaneous coil localization of multiple PNs was higher than that with localization of a single PN, but this method was safe and feasible.

Computed Tomography-Guided Trans-scapular Coil Localization for Pulmonary Nodules.

The aim of the study is to evaluate the feasibility, safety, and effectiveness of preoperative computed tomography (CT)-guided trans-scapular coil localization (TSCL) of scapula-blocked pulmonary nodules (PNs). Between November 2015 and May 2020, 11 patients underwent preoperative CT-guided TSCL procedures owing to PN occlusion by scapula. A 100% technical success rate was achieved for CT-guided TSCL, with one coil being used for each PN. One patient (9.1%) developed pneumothorax. Successful video-assisted thoracoscopic surgery (VATS)-guided wedge resection of these scapula-blocked PNs was conducted in all patients. CT-guided TSCL can be simply and safely used to facilitate successful VATS-guided wedge resection of scapula-blocked PNs.