1
|
Vijayan R, Sheth N, Mekki L, Lu A, Uneri A, Sisniega A, Magaraggia J, Kleinszig G, Vogt S, Thiboutot J, Lee H, Yarmus L, Siewerdsen JH. 3D-2D image registration in the presence of soft-tissue deformation in image-guided transbronchial interventions. Phys Med Biol 2022; 68. [PMID: 36317269 DOI: 10.1088/1361-6560/ac9e3c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022]
Abstract
Purpose. Target localization in pulmonary interventions (e.g. transbronchial biopsy of a lung nodule) is challenged by deformable motion and may benefit from fluoroscopic overlay of the target to provide accurate guidance. We present and evaluate a 3D-2D image registration method for fluoroscopic overlay in the presence of tissue deformation using a multi-resolution/multi-scale (MRMS) framework with an objective function that drives registration primarily by soft-tissue image gradients.Methods. The MRMS method registers 3D cone-beam CT to 2D fluoroscopy without gating of respiratory phase by coarse-to-fine resampling and global-to-local rescaling about target regions-of-interest. A variation of the gradient orientation (GO) similarity metric (denotedGO') was developed to downweight bone gradients and drive registration via soft-tissue gradients. Performance was evaluated in terms of projection distance error at isocenter (PDEiso). Phantom studies determined nominal algorithm parameters and capture range. Preclinical studies used a freshly deceased, ventilated porcine specimen to evaluate performance in the presence of real tissue deformation and a broad range of 3D-2D image mismatch.Results. Nominal algorithm parameters were identified that provided robust performance over a broad range of motion (0-20 mm), including an adaptive parameter selection technique to accommodate unknown mismatch in respiratory phase. TheGO'metric yielded median PDEiso= 1.2 mm, compared to 6.2 mm for conventionalGO.Preclinical studies with real lung deformation demonstrated median PDEiso= 1.3 mm with MRMS +GO'registration, compared to 2.2 mm with a conventional transform. Runtime was 26 s and can be reduced to 2.5 s given a prior registration within ∼5 mm as initialization.Conclusions. MRMS registration via soft-tissue gradients achieved accurate fluoroscopic overlay in the presence of deformable lung motion. By driving registration via soft-tissue image gradients, the method avoided false local minima presented by bones and was robust to a wide range of motion magnitude.
Collapse
Affiliation(s)
- R Vijayan
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - N Sheth
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - L Mekki
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - A Lu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - A Uneri
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - A Sisniega
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | | | | | - S Vogt
- Siemens Healthineers, Erlangen, Germany
| | - J Thiboutot
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins Medical Institution, Baltimore, MD, United States of America
| | - H Lee
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins Medical Institution, Baltimore, MD, United States of America
| | - L Yarmus
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins Medical Institution, Baltimore, MD, United States of America
| | - J H Siewerdsen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America.,Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| |
Collapse
|
2
|
Han R, Uneri A, Vijayan RC, Wu P, Vagdargi P, Sheth N, Vogt S, Kleinszig G, Osgood GM, Siewerdsen JH. Fracture reduction planning and guidance in orthopaedic trauma surgery via multi-body image registration. Med Image Anal 2020; 68:101917. [PMID: 33341493 DOI: 10.1016/j.media.2020.101917] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 02/06/2023]
Abstract
PURPOSES Surgical reduction of pelvic fracture is a challenging procedure, and accurate restoration of natural morphology is essential to obtaining positive functional outcome. The procedure often requires extensive preoperative planning, long fluoroscopic exposure time, and trial-and-error to achieve accurate reduction. We report a multi-body registration framework for reduction planning using preoperative CT and intraoperative guidance using routine 2D fluoroscopy that could help address such challenges. METHOD The framework starts with semi-automatic segmentation of fractured bone fragments in preoperative CT using continuous max-flow. For reduction planning, a multi-to-one registration is performed to register bone fragments to an adaptive template that adjusts to patient-specific bone shapes and poses. The framework further registers bone fragments to intraoperative fluoroscopy to provide 2D fluoroscopy guidance and/or 3D navigation relative to the reduction plan. The framework was investigated in three studies: (1) a simulation study of 40 CT images simulating three fracture categories (unilateral two-body, unilateral three-body, and bilateral two-body); (2) a proof-of-concept cadaver study to mimic clinical scenario; and (3) a retrospective clinical study investigating feasibility in three cases of increasing severity and accuracy requirement. RESULTS Segmentation of simulated pelvic fracture demonstrated Dice coefficient of 0.92±0.06. Reduction planning using the adaptive template achieved 2-3 mm and 2-3° error for the three fracture categories, significantly better than planning based on mirroring of contralateral anatomy. 3D-2D registration yielded ~2 mm and 0.5° accuracy, providing accurate guidance with respect to the preoperative reduction plan. The cadaver study and retrospective clinical study demonstrated comparable accuracy: ~0.90 Dice coefficient in segmentation, ~3 mm accuracy in reduction planning, and ~2 mm accuracy in 3D-2D registration. CONCLUSION The registration framework demonstrated planning and guidance accuracy within clinical requirements in both simulation and clinical feasibility studies for a broad range of fracture-dislocation patterns. Using routinely acquired preoperative CT and intraoperative fluoroscopy, the framework could improve the accuracy of pelvic fracture reduction, reduce radiation dose, and could integrate well with common clinical workflow without the need for additional navigation systems.
Collapse
Affiliation(s)
- R Han
- Department of Biomedical Engineering, The Johns Hopkins University, BaltimoreMD, United States
| | - A Uneri
- Department of Biomedical Engineering, The Johns Hopkins University, BaltimoreMD, United States
| | - R C Vijayan
- Department of Biomedical Engineering, The Johns Hopkins University, BaltimoreMD, United States
| | - P Wu
- Department of Biomedical Engineering, The Johns Hopkins University, BaltimoreMD, United States
| | - P Vagdargi
- Department of Computer Science, The Johns Hopkins University, BaltimoreMD, United States
| | - N Sheth
- Department of Biomedical Engineering, The Johns Hopkins University, BaltimoreMD, United States
| | - S Vogt
- Siemens Healthineers, ErlangenGermany
| | | | - G M Osgood
- Department of Orthopaedic Surgery, The Johns Hopkins Hospital, BaltimoreMD, United States
| | - J H Siewerdsen
- Department of Biomedical Engineering, The Johns Hopkins University, BaltimoreMD, United States.
| |
Collapse
|
3
|
Wu P, Sheth N, Sisniega A, Uneri A, Han R, Vijayan R, Vagdargi P, Kreher B, Kunze H, Kleinszig G, Vogt S, Lo SF, Theodore N, Siewerdsen JH. C-arm orbits for metal artifact avoidance (MAA) in cone-beam CT. Phys Med Biol 2020; 65:165012. [PMID: 32428891 PMCID: PMC8650760 DOI: 10.1088/1361-6560/ab9454] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Metal artifacts present a challenge to cone-beam CT (CBCT) image-guided surgery, obscuring visualization of metal instruments and adjacent anatomy-often in the very region of interest pertinent to the imaging/surgical tasks. We present a method to reduce the influence of metal artifacts by prospectively defining an image acquisition protocol-viz., the C-arm source-detector orbit-that mitigates metal-induced biases in the projection data. The metal artifact avoidance (MAA) method is compatible with simple mobile C-arms, does not require exact prior information on the patient or metal implants, and is consistent with 3D filtered backprojection (FBP), more advanced (e.g. polyenergetic) model-based image reconstruction (MBIR), and metal artifact reduction (MAR) post-processing methods. The MAA method consists of: (i) coarse localization of metal objects in the field-of-view (FOV) via two or more low-dose scout projection views and segmentation (e.g. a simple U-Net) in coarse backprojection; (ii) model-based prediction of metal-induced x-ray spectral shift for all source-detector vertices accessible by the imaging system (e.g. gantry rotation and tilt angles); and (iii) identification of a circular or non-circular orbit that reduces the variation in spectral shift. The method was developed, tested, and evaluated in a series of studies presenting increasing levels of complexity and realism, including digital simulations, phantom experiment, and cadaver experiment in the context of image-guided spine surgery (pedicle screw implants). The MAA method accurately predicted tilted circular and non-circular orbits that reduced the magnitude of metal artifacts in CBCT reconstructions. Realistic distributions of metal instrumentation were successfully localized (0.71 median Dice coefficient) from 2-6 low-dose scout views even in complex anatomical scenes. The MAA-predicted tilted circular orbits reduced root-mean-square error (RMSE) in 3D image reconstructions by 46%-70% and 'blooming' artifacts (apparent width of the screw shaft) by 20-45%. Non-circular orbits defined by MAA achieved a further ∼46% reduction in RMSE compared to the best (tilted) circular orbit. The MAA method presents a practical means to predict C-arm orbits that minimize spectral bias from metal instrumentation. Resulting orbits-either simple tilted circular orbits or more complex non-circular orbits that can be executed with a motorized multi-axis C-arm-exhibited substantial reduction of metal artifacts in raw CBCT reconstructions by virtue of higher fidelity projection data, which are in turn compatible with subsequent MAR post-processing and/or polyenergetic MBIR to further reduce artifacts.
Collapse
Affiliation(s)
- P Wu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Han R, Uneri A, Ketcha M, Vijayan R, Sheth N, Wu P, Vagdargi P, Vogt S, Kleinszig G, Osgood GM, Siewerdsen JH. Multi-body 3D-2D registration for image-guided reduction of pelvic dislocation in orthopaedic trauma surgery. Phys Med Biol 2020; 65:135009. [PMID: 32217833 PMCID: PMC8647002 DOI: 10.1088/1361-6560/ab843c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Surgical reduction of pelvic dislocation is a challenging procedure with poor long-term prognosis if reduction does not accurately restore natural morphology. The procedure often requires long fluoroscopic exposure times and trial-and-error to achieve accurate reduction. We report a method to automatically compute the target pose of dislocated bones in preoperative CT and provide 3D guidance of reduction using routine 2D fluoroscopy. A pelvic statistical shape model (SSM) and a statistical pose model (SPM) were formed from an atlas of 40 pelvic CT images. Multi-body bone segmentation was achieved by mapping the SSM to a preoperative CT via an active shape model. The target reduction pose for the dislocated bone is estimated by fitting the poses of undislocated bones to the SPM. Intraoperatively, multiple bones are registered to fluoroscopy images via 3D-2D registration to obtain 3D pose estimates from 2D images. The method was examined in three studies: (1) a simulation study of 40 CT images simulating a range of dislocation patterns; (2) a pelvic phantom study with controlled dislocation of the left innominate bone; (3) a clinical case study investigating feasibility in images acquired during pelvic reduction surgery. Experiments investigated the accuracy of registration as a function of initialization error (capture range), image quality (radiation dose and image noise), and field of view (FOV) size. The simulation study achieved target pose estimation with translational error of median 2.3 mm (1.4 mm interquartile range, IQR) and rotational error of 2.1° (1.3° IQR). 3D-2D registration yielded 0.3 mm (0.2 mm IQR) in-plane and 0.3 mm (0.2 mm IQR) out-of-plane translational error, with in-plane capture range of ±50 mm and out-of-plane capture range of ±120 mm. The phantom study demonstrated 3D-2D target registration error of 2.5 mm (1.5 mm IQR), and the method was robust over a large dose range, down to 5 [Formula: see text]Gy/frame (an order of magnitude lower than the nominal fluoroscopic dose). The clinical feasibility study demonstrated accurate registration with both preoperative and intraoperative radiographs, yielding 3.1 mm (1.0 mm IQR) projection distance error with robust performance for FOV ranging from 340 × 340 mm2 to 170 × 170 mm2 (at the image plane). The method demonstrated accurate estimation of the target reduction pose in simulation, phantom, and a clinical feasibility study for a broad range of dislocation patterns, initialization error, dose levels, and FOV size. The system provides a novel means of guidance and assessment of pelvic reduction from routinely acquired preoperative CT and intraoperative fluoroscopy. The method has the potential to reduce radiation dose by minimizing trial-and-error and to improve outcomes by guiding more accurate reduction of joint dislocations.
Collapse
Affiliation(s)
- R Han
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| | - A Uneri
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| | - M Ketcha
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| | - R Vijayan
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| | - N Sheth
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| | - P Wu
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| | - P Vagdargi
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| | - S Vogt
- Siemens Healthineers, Erlangen, Germany
| | | | - G M Osgood
- Department of Orthopaedic Surgery, The Johns Hopkins Hospital, Baltimore, MD, United States of America
| | - J H Siewerdsen
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States of America
| |
Collapse
|
5
|
Woelfle UC, Briggs T, Bhattacharyya S, Qu H, Sheth N, Knabe C, Ducheyne P. Dual local drug delivery of vancomycin and farnesol for mitigation of MRSA infection in vivo - a pilot study. Eur Cell Mater 2020; 40:38-57. [PMID: 32696976 DOI: 10.22203/ecm.v040a03] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Surgical site infections after orthopaedic surgery using fracture fixation devices or endosseous implants create major surgical challenges with severe adverse effects, such as osteomyelitis. These infections are frequently caused by Staphylococcus aureus, often with high resistance to antibiotics, such as methicillin-resistant Staphylococcus aureus (MRSA). Due to the formation of impenetrable biofilms on implant surfaces, systemic antibiotic treatment has become exceedingly difficult. New solutions are pursued by combining several drugs using a controlled delivery system from specifically engineered implant surfaces. A sol-gel coating on titanium implants was previously developed with 20 wt % vancomycin and 30 wt % farnesol, with suppression of MRSA in vitro. The present study investigated the efficacy of sol-gel film coatings for controlled dual local delivery over 4 weeks utilising a rat infection model. The findings confirmed the viability of this new concept in vivo based on the differences observed between coatings containing vancomycin alone (SGV) and the dual-drug-containing coating with vancomycin and farnesol (SGVF). While both the SGVF and SGV coatings facilitated excellent preservation of the osseous microarchitecture, SGVF coating displayed a slightly higher potency for suppressing MRSA infiltration than SGV, in combination with a lower reactive bone remodelling activity, most likely by disturbing biofilm formation. The next step for advancing the concept of dual-drug delivery from sol-gel coatings to the clinic and confirming the promising effect of the SGVF coatings on reactive bone remodelling and suppressing MRSA infiltration is a study in a larger animal species with longer time points.
Collapse
Affiliation(s)
| | | | | | | | | | - C Knabe
- Department of Experimental Orofacial Medicine, Philipps University, Marburg,
| | | |
Collapse
|
6
|
Vagdargi P, Uneri A, Sheth N, Sisniega A, De Silva T, Osgood GM, Siewerdsen JH. Calibration and Registration of a Freehand Video-Guided Surgical Drill for Orthopaedic Trauma. Proc SPIE Int Soc Opt Eng 2020; 11315. [PMID: 32476703 DOI: 10.1117/12.2550001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Pelvic trauma surgical procedures rely heavily on guidance with 2D fluoroscopy views for navigation in complex bone corridors. This "fluoro-hunting" paradigm results in extended radiation exposure and possible suboptimal guidewire placement from limited visualization of the fractures site with overlapped anatomy in 2D fluoroscopy. A novel computer vision-based navigation system for freehand guidewire insertion is proposed. The navigation framework is compatible with the rapid workflow in trauma surgery and bridges the gap between intraoperative fluoroscopy and preoperative CT images. The system uses a drill-mounted camera to detect and track poses of simple multimodality (optical/radiographic) markers for registration of the drill axis to fluoroscopy and, in turn, to CT. Surgical navigation is achieved with real-time display of the drill axis position on fluoroscopy views and, optionally, in 3D on the preoperative CT. The camera was corrected for lens distortion effects and calibrated for 3D pose estimation. Custom marker jigs were constructed to calibrate the drill axis and tooltip with respect to the camera frame. A testing platform for evaluation of the navigation system was developed, including a robotic arm for precise, repeatable, placement of the drill. Experiments were conducted for hand-eye calibration between the drill-mounted camera and the robot using the Park and Martin solver. Experiments using checkerboard calibration demonstrated subpixel accuracy [-0.01 ± 0.23 px] for camera distortion correction. The drill axis was calibrated using a cylindrical model and demonstrated sub-mm accuracy [0.14 ± 0.70 mm] and sub-degree angular deviation.
Collapse
Affiliation(s)
- P Vagdargi
- Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA 21218
| | - A Uneri
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA 21218
| | - N Sheth
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA 21218
| | - A Sisniega
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA 21218
| | - T De Silva
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA 21218
| | - G M Osgood
- Department of Orthopedic Surgery, Johns Hopkins Medicine, Baltimore, MD, USA 21218
| | - J H Siewerdsen
- Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA 21218.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA 21218
| |
Collapse
|
7
|
Kavi A, Lee A, Lederman A, Sheth N, Safdieh J, Schreiber D. Patterns of Care and Comparison of Outcomes between Patients with Inflammatory Breast Cancer Who Were Treated with Standard versus Dose-Escalated Adjuvant Radiation Therapy. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
8
|
Sheth N, Osborn V, Lee A, Kavi A, Schreiber D, Safdieh J. Burnout in Radiation Oncology: A Pilot Residency Wellness Program. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.2121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
9
|
Sheth N, Osborn V, Adedoyin P, Safdieh J, Schreiber D. Hepatocellular Carcinoma: Patterns of Care and Outcomes for Patients receiving Stereotactic Radiation Therapy. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Lee A, Tam M, Wu P, Gerber N, Lederman A, Garay E, Sheth N, Safdieh J, Choi K, Schreiber D. Patterns of Care of Adjuvant Radiation Therapy after Lumpectomy and Survival in T1N0M0 Estrogen Receptor Positive Breast Cancer. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.1622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
11
|
Kavi A, Lee A, Sheth N, Adedoyin P, Lederman A, Schreiber D. Patterns of Care and Comparison of Outcomes Between Primary Anal Squamous Cell Carcinoma and Anal Adenocarcinoma. Int J Radiat Oncol Biol Phys 2018. [DOI: 10.1016/j.ijrobp.2018.07.210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
12
|
De Silva T, Uneri A, Zhang X, Ketcha M, Han R, Sheth N, Martin A, Vogt S, Kleinszig G, Belzberg A, Sciubba DM, Siewerdsen JH. Real-time, image-based slice-to-volume registration for ultrasound-guided spinal intervention. Phys Med Biol 2018; 63:215016. [PMID: 30372418 DOI: 10.1088/1361-6560/aae761] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Real-time fusion of magnetic resonance (MR) and ultrasound (US) images could facilitate safe and accurate needle placement in spinal interventions. We develop an entirely image-based registration method (independent of or complementary to surgical trackers) that includes an efficient US probe pose initialization algorithm. The registration enables the simultaneous display of 2D ultrasound image slices relative to 3D pre-procedure MR images for navigation. A dictionary-based 3D-2D pose initialization algorithm was developed in which likely probe positions are predefined in a dictionary with feature encoding by Haar wavelet filters. Feature vectors representing the 2D US image are computed by scaling and translating multiple Haar basis filters to capture scale, location, and relative intensity patterns of distinct anatomical features. Following pose initialization, fast 3D-2D registration was performed by optimizing normalized cross-correlation between intra- and pre-procedure images using Powell's method. Experiments were performed using a lumbar puncture phantom and a fresh cadaver specimen presenting realistic image quality in spinal US imaging. Accuracy was quantified by comparing registration transforms to ground truth motion imparted by a computer-controlled motion system and calculating target registration error (TRE) in anatomical landmarks. Initialization using a 315-length feature vector yielded median translation accuracy of 2.7 mm (3.4 mm interquartile range, IQR) in the phantom and 2.1 mm (2.5 mm IQR) in the cadaver. By comparison, storing the entire image set in the dictionary and optimizing correlation yielded a comparable median accuracy of 2.1 mm (2.8 mm IQR) in the phantom and 2.9 mm (3.5 mm IQR) in the cadaver. However, the dictionary-based method reduced memory requirements by 47× compared to storing the entire image set. The overall 3D error after registration measured using 3D landmarks was 3.2 mm (1.8 mm IQR) mm in the phantom and 3.0 mm (2.3 mm IQR) mm in the cadaver. The system was implemented in a 3D Slicer interface to facilitate translation to clinical studies. Haar feature based initialization provided accuracy and robustness at a level that was sufficient for real-time registration using an entirely image-based method for ultrasound navigation. Such an approach could improve the accuracy and safety of spinal interventions in broad utilization, since it is entirely software-based and can operate free from the cost and workflow requirements of surgical trackers.
Collapse
Affiliation(s)
- T De Silva
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, United States of America
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Sheth N, Osborn V, Lee A, Schwartz D, Schreiber D. Association of Nadir PSA >0.5ng/Ml after Dose Escalated External Beam Radiation With Prostate Cancer-Specific Endpoints. Int J Radiat Oncol Biol Phys 2017. [DOI: 10.1016/j.ijrobp.2017.06.1235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
14
|
Osborn V, Givi B, Roden D, Katsoulakis E, Sheth N, Lederman A, Schwartz D, Schreiber D. Patterns of Care and Outcomes of Adjuvant Therapy for High Risk Head and Neck Cancer After Surgery. Int J Radiat Oncol Biol Phys 2017. [DOI: 10.1016/j.ijrobp.2017.06.1470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
15
|
Salvo G, Iniesta M, Lasala J, Meyer L, Munsell M, Sheth N, Ramirez P. Bowel procedures during gynecologic surgery on an enhanced recovery program (ERP): Are perioperative outcomes compromised? Gynecol Oncol 2017. [DOI: 10.1016/j.ygyno.2017.03.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
16
|
Bulat E, Davey S, Massawe H, Pallangyo A, Premkumar A, Sheth N. The Prevalence of Proximal DVT in Orthopaedic Trauma Patients in Northern
Tanzania Without the Routine Use of Thromboprophylaxis. Ann Glob Health 2017. [DOI: 10.1016/j.aogh.2017.03.170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
17
|
Sheth N, Tabibian A, Rose J, Alvelo M, Perel C, Laiken K, Kim A. SU-F-T-604: Dosimetric Evaluation of Intracranial Stereotactic Radiotherapy Plans On a LINAC. Med Phys 2016. [DOI: 10.1118/1.4956789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
18
|
Tabibian A, Kim A, Rose J, Alvelo M, Perel C, Laiken K, Sheth N. SU-F-T-387: A Novel Optimization Technique for Field in Field (FIF) Chestwall Radiation Therapy Using a Single Plan to Improve Delivery Safety and Treatment Planning Efficiency. Med Phys 2016. [DOI: 10.1118/1.4956572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
19
|
Mistry N, Kim A, Schaum J, Bermudez M, Driscoll K, Holowinski C, Yang C, Chen Y, Sheth N. SU-E-T-320: Dosimetric Evaluation of Intracranial Stereotactic Radiotherapy Plans Using Jaws-Only Collimation On a LINAC. Med Phys 2015. [DOI: 10.1118/1.4924681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
20
|
Locatelli F, Choukroun G, Fliser D, Moecks J, Wiggenhauser A, Gupta A, Swinkels DW, Lin V, Guss C, Pratt R, Carrilho P, Martins AR, Alves M, Mateus A, Gusmao L, Parreira L, Assuncao J, Rodrigues I, Stamopoulos D, Mpakirtzi N, Afentakis N, Grapsa E, Zitt E, Sturm G, Kronenberg F, Neyer U, Knoll F, Lhotta K, Weiss G, Robinson BM, Larkina M, Bieber B, Kleophas W, Li Y, Locatelli F, McCullough K, Nolen JG, Port FK, Pisoni RL, Kalicki RM, Uehlinger DE, Ogawa C, Kanda F, Tomosugi N, Maeda T, Kuji T, Fujikawa T, Shino M, Shibata K, Kaneda T, Nishihara M, Satta H, Kawata SI, Koguchi N, Tamura K, Hirawa N, Toya Y, Umemura S, Chanliau J, Martin H, Stamatelou K, Gonzalez-Tabares L, Manamley N, Farouk M, Addison J, Donck J, Schneider A, Gutjahr-Lengsfeld L, Ritz E, Scharnagl H, Gelbrich G, Pilz S, Macdougall IC, Wanner C, Drechsler C, Kuntsevich V, Charen E, Kobena D, Sheth N, Siktel H, Levin NW, Winchester JF, Kotanko P, Kaysen G, Kuragano T, Kida A, Yahiro M, Nanami M, Nagasawa Y, Hasuike Y, Nakanishi T, Stamopoulos D, Mpakirtzi N, Dimitratou V, Griveas I, Lianos E, Grapsa E, Sasaki Y, Yamazaki S, Fujita K, Kurasawa M, Yorozu K, Shimonaka Y, Suzuki N, Yamamoto M, Zwiech R, Szczepa ska J, Bruzda-Zwiech A, Rao A, Gilg J, Caskey F, Kirkpantur A, Balci MM, Turkvatan A, Afsar B, Alkis M, Mandiroglu F, Kim YO, Yoon SA, Kim YS, Choi SJ, Min JW, Cheong MA, Hasuike Y, Kida A, Oue M, Yamamoto K, Kimura T, Fukao W, Yahiro M, Kaibe S, Nanami M, Nakanishi T, Djuric PS, Ikonomovski J, Tosic J, Jankovic A, Majster Z, Stankovic Popovic V, Dimkovic N, Aicardi Spalloni V, Del Vecchio L, Longhi S, Violo L, La Milia V, Pontoriero G, Locatelli F, Shino M, Kuji T, Fujikawa T, Toya Y, Umemura S, Macdougall I, Rumjon A, Mangahis E, Goldstein L, Ryzlewicz T, Becker F, Kilgallon W, Fukasawa M, Otake Y, Yamagishi T, Kamiyama M, Kobayashi H, Takeda M, Toida T, Sato Y, Fujimoto S. DIALYSIS ANAEMIA. Nephrol Dial Transplant 2014. [DOI: 10.1093/ndt/gfu176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
21
|
Coleman AJ, Penney GP, Richardson TJ, Guyot A, Choi MJ, Sheth N, Craythorne E, Robson A, Mallipeddi R. Automated registration of optical coherence tomography and dermoscopy in the assessment of sub-clinical spread in basal cell carcinoma. ACTA ACUST UNITED AC 2014; 19:1-12. [PMID: 24784842 PMCID: PMC4075257 DOI: 10.3109/10929088.2014.885085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Optical coherence tomography (OCT) has been shown to be of clinical value in imaging basal cell carcinoma (BCC). A novel dual OCT-video imaging system, providing automated registration of OCT and dermoscopy, has been developed to assess the potential of OCT in measuring the degree of sub-clinical spread of BCC. Seventeen patients selected for Mohs micrographic surgery (MMS) for BCC were recruited to the study. The extent of BCC infiltration beyond a segment of the clinically assessed pre-surgical border was evaluated using OCT. Sufficiently accurate (<0.5 mm) registration of OCT and dermoscopy images was achieved in 9 patients. The location of the OCT-assessed BCC border was also compared with that of the final surgical defect. Infiltration of BCC across the clinical border ranged from 0 mm to >2.5 mm. In addition, the OCT border lay between 0.5 mm and 2.0 mm inside the final MMS defect in those cases where this could be assessed. In one case, where the final MMS defect was over 17 mm from the clinical border, OCT showed >2.5 mm infiltration across the clinical border at the FOV limit. These results provide evidence that OCT allows more accurate assessment of sub-clinical spread of BCC than clinical observation alone. Such a capability may have clinical value in reducing the number of surgical stages in MMS for BCC. There may also be a role for OCT in aiding the selection of patients most suitable for MMS.
Collapse
Affiliation(s)
- A J Coleman
- Medical Physics Department, Guy's and St. Thomas' Foundation Trust , London
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Anchlia S, Parmar B, Garg B, Sheth N, Agarwal M. Outcome assessment of six different surgical techniques in the management of temporomandibular joint ankylosis. A retrospective evaluation of 467 joints. Int J Oral Maxillofac Surg 2013. [DOI: 10.1016/j.ijom.2013.07.664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
23
|
Barlow R, Mallipeddi R, Sheth N. Is Mohs micrographic surgery more effective than wide local excision for treatment of dermatofibrosarcoma protuberans in reducing risk of local recurrence? A critically appraised topic. Br J Dermatol 2012; 168:229-30. [DOI: 10.1111/bjd.12053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
24
|
Sheth N, Mistry N, Sim S, Weiss M, Grebler A, Geltzeiler J, Litvin Y, Keselman I, Waldman I, Yang C. Validation of Inverse Planning-simulated Annealing Class Solution for Prostate High-dose-rate Brachytherapy. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
25
|
Sheth N, Chen Y, Yang J. SU-E-T-453: Optimization of Dose Gradient for Gamma Knife Radiosurgery. Med Phys 2012; 39:3809. [DOI: 10.1118/1.4735542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
26
|
Yang C, Sheth N, Chen Y. SU-E-T-378: Dosimetry Comparison of VMAT and Tomotherapy Plans with Dose Painting in Brain Metastases. Med Phys 2012. [DOI: 10.1118/1.4735465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
27
|
Sheth N, Mistry N, Chen Y, Yang C. SU-E-T-428: Class Solution for Prostate High Dose Rate Brachytherapy with Inverse Planning Simulated Annealing. Med Phys 2012; 39:3803. [DOI: 10.1118/1.4735517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
28
|
Sheth N, Kandala S, Chen Y, Yang C. SU-E-J-34: Influence of Prone versus Supine Patient Position on Localization with Image Guided Radiotherapy of Prostate Cancer. Med Phys 2012; 39:3660. [DOI: 10.1118/1.4734868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
29
|
Cunha D, Richardson T, Sheth N, Orchard G, Coleman A, Mallipeddi R. Comparison of ex vivo optical coherence tomography with conventional frozen-section histology for visualizing basal cell carcinoma during Mohs micrographic surgery. Br J Dermatol 2011; 165:576-80. [DOI: 10.1111/j.1365-2133.2011.10461.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
30
|
Sheth N, Cheng J, Jani A, Sim S, Murphy S, Chen Y, Stapleton P, Winant S, Yang C. SU-E-T-877: Dosimetric Evaluation of Intracranial Stereotactic Radiotherapy with Helical Tomotherapy. Med Phys 2011. [DOI: 10.1118/1.3612841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
31
|
Yang C, Chen Y, Sheth N, Murphy S, Wu G. SU-E-T-617: Dosimetric Comparison of Prone Breast Treatment on Tomotherapy and Conventional LINAC. Med Phys 2011. [DOI: 10.1118/1.3612580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
32
|
Murphy S, Yang C, Sheth N, Chen Y. TU-A-BRA-01: Non-Coplanar Treatment of Hypofractionated Intracranial SRT with Tomotherapy. Med Phys 2010. [DOI: 10.1118/1.3469162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
33
|
Sheth N, Murphy S, Chen Y, Yang C. SU-GG-I-103: Comparison of Model-Based Segmentation Systems for Contouring of Male Pelvic Structures. Med Phys 2010. [DOI: 10.1118/1.4755940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
34
|
Murphy S, Sim S, Sheth N, Weiss M, Yang J. Intracranial Hypofractionated Stereotactic Radiotherapy with Different Head Positions Utilizing a New Positioning Device. Int J Radiat Oncol Biol Phys 2009. [DOI: 10.1016/j.ijrobp.2009.07.1546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
35
|
Sheth N, Sarker SJ, Harries M, Healy C, Russell-Jones R, Acland K. Predictors of patient satisfaction with initial diagnosis and management of malignant melanoma. Clin Exp Dermatol 2009; 35:599-602. [DOI: 10.1111/j.1365-2230.2009.03639.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
36
|
Sheth N, Yang C, Murphy S, Weiss M, Sim S. SU-FF-T-87: Dose Reconstruction of Intracranial Hypofractionated Helical Tomotherapy Treatments for Adaptive Planning. Med Phys 2009. [DOI: 10.1118/1.3181560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
37
|
|
38
|
Yang C, Sheth N, Murphy S, Sim S, Chen Y. SU-FF-T-664: Dose Grid Effects in Adaptive Planning of Helical TomoTherapy for Hypofractionated Treatments. Med Phys 2009. [DOI: 10.1118/1.3182162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
39
|
Vaghasiya J, Sheth N, Bhalodia Y, Jivani N. Diabetes type-II exaggerates renal ischemia reperfusion injury by elevation of oxidative stress and inflammatory response. J Young Pharm 2009. [DOI: 10.4103/0975-1483.55748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
40
|
Yang C, Weiss M, Sheth N, Murphy S. An Efficient Way to Determine the Needle Tip in Real Time Seed Implant Procedure. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
41
|
|
42
|
Yang C, Sheth N, Murphy S, Chen Y. SU-GG-T-33: Accurate Localization of the Needle Position During the Real Time Seed Implant Procedure in OR. Med Phys 2008. [DOI: 10.1118/1.2961783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
43
|
Sheth N, Murphy S, Yang C. SU-GG-J-55: Comparison of Megavoltage Imaging Modalities and Spatial Effects for Dose Calculations. Med Phys 2008. [DOI: 10.1118/1.2963111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
44
|
|
45
|
|
46
|
Sheth N, Greenblatt D, McGrath JA. New KRT10 gene mutation underlying the annular variant of bullous congenital ichthyosiform erythroderma with clinical worsening during pregnancy. Br J Dermatol 2007; 157:602-4. [PMID: 17596149 DOI: 10.1111/j.1365-2133.2007.08054.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- N Sheth
- Department of Dermatology, Ealing Hospital, Southall UB1 3HW, UK.
| | | | | |
Collapse
|
47
|
|
48
|
Abstract
Use of RNA interference (RNAi) in forward genetic screens is proliferating. Currently, short-interfering RNAs (siRNAs) and short-hairpin RNAs (shRNAs) are being used to silence genes to tease out functional information. It is becoming easier to harness RNAi to silence specific genes, owing to the development of libraries of readymade shRNA and siRNA gene-silencing constructs by using a variety of sources. RNAi Codex, which consists of a database of shRNA related information and an associated website, has been developed as a portal for publicly available shRNA resources and is accessible at . RNAi Codex currently holds data from the Hannon–Elledge shRNA library and allows the use of biologist-friendly gene names to access information on shRNA constructs that can silence the gene of interest. It is designed to hold user-contributed annotations and publications for each construct, as and when such data become available. We will describe features of RNAi Codex and explain the use of the tool.
Collapse
Affiliation(s)
| | | | | | | | - R. Sachidanandam
- To whom correspondence should be addressed. Tel: +1 516 367 8864; Fax: +1 516 367 8389;
| |
Collapse
|
49
|
Abstract
STUDY DESIGN A basic science biomechanical study involving an animal model. OBJECTIVES To evaluate the effect of varying angles of halo pin insertion on the force generated at the pin-bone interface, and thereby the stability of the halo pin-bone interaction during insertion. BACKGROUND DATA Because of variations in the shape and size of the pediatric skull, halo pins often are inserted at various angles rather than perpendicular to the skull. Concern exists that the high complication rate associated with pediatric halo use may result in part from less than ideal structural properties at the halo pin-bone interface. METHODS The authors used a fetal calf skull model to simulate the thickness and structural properties of the pediatric skull. Halo pins were inserted at angles of 0 degree (perpendicular), 10 degrees, 15 degrees, and 30 degrees into skull segments via a halo ring. Load generated at the pin-bone interface was measured using a modified mechanical testing device. Twenty trials were conducted per angle, with the endpoint being specimen failure, pin penetration, or maximum load. RESULTS Mean maximum loads per unit thickness were 82.15 +/- 7.54 N/mm at 0 degree, 68.80 +/- 4.79 N/mm at 10 degrees, 51.49 +/- 5.08 N/mm at 15 degrees, and 42.38 +/- 3.51 N/mm at 30 degrees, There was a significant difference between perpendicular insertion (0 degree) and 15 degrees angles of insertion. There was also a significant difference between the 10 degrees and 30 degrees angles of insertion. CONCLUSIONS Perpendicular halo pin insertion in an immature skull model was shown to result in increased load at the pin-bone interface. This improved structural behavior may help to reduce the incidence of complications of halo application in children.
Collapse
Affiliation(s)
- L A Copley
- Department of Orthopaedic Surgery, Eglin Hospital, Eglin AFB, Florida, USA
| | | | | | | | | |
Collapse
|
50
|
Shin DH, Kim YY, Sheth N, Ren J, Shah M, Kim C, Yang KJ. The role of adjunctive mitomycin C in secondary glaucoma triple procedure as compared to primary glaucoma triple procedure. Ophthalmology 1998; 105:740-5. [PMID: 9544650 DOI: 10.1016/s0161-6420(98)94032-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE This study aimed to investigate whether previously failed glaucoma filtration surgery is a risk factor for filtration failure of subsequent trabeculectomy combined with cataract surgery and to determine the role of adjunctive mitomycin C (MMC) in the secondary glaucoma triple procedure (SGTP) as compared to primary glaucoma triple procedure (PGTP). DESIGN A prospective, controlled study that was randomized with respect to assignment to adjunctive MMC and a case-control design with respect to comparisons between SGTP and PGTP was studied. PARTICIPANTS The SGTP group consisted of 49 eyes of 49 consecutive patients with primary open-angle glaucoma with a history of glaucoma filtration surgery requiring glaucoma medical therapy and in need of cataract surgery, randomized to adjunctive MMC (SGTP MMC subgroup of 21 eyes) and no adjunctive MMC (SGTP control subgroup of 28 eyes). The PGTP group consisted of 49 PGTP cases closely matched to the SGTP cases with respect to age, race, gender, MMC use, C:D ratio, and systemic diseases. INTERVENTION Trabeculectomy combined with phacoemulsification and a small incision (5 x 6 mm), all polymethylmethacrylate posterior chamber intraocular lens implantation with or without adjunctive MMC (0.5 mg/ml for 1 minute), was performed. MAIN OUTCOME MEASURES Surgery failure was defined as the need of an additional intraocular procedure or the need of more than one medication to achieve intraocular pressure control to the target level. Intragroup and intergroup comparisons were made with respect to filtration outcome among the SGTP and PGTP patients. RESULTS Without adjunctive MMC, filtration success was significantly less in SGTP than in PGTP (P = 0.03). Adjunctive MMC significantly increased the success rate of SGTP (P = 0.02) but not that of PGTP (P = 0.89) over the average follow-up period of 2 years. CONCLUSIONS Previously failed glaucoma filtration surgery is a significant risk factor for the filtration failure of combined surgery. Intraoperative use of adjunctive MMC significantly improves the filtration success rate of SGTP.
Collapse
Affiliation(s)
- D H Shin
- Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan 48201-1423, USA
| | | | | | | | | | | | | |
Collapse
|