Comparison of the accuracy of voxel based registration and surface based registration for 3D assessment of surgical change following orthognathic surgery

Purpose: Superimposition of two dimensional preoperative and postoperative facial images, including radiographs and photographs, are used to evaluate the surgical changes after orthognathic surgery. Recently, three dimensional (3D) imaging has been introduced allowing more accurate analysis of surgical changes. Surface based registration and voxel based registration are commonly used methods for 3D superimposition. The aim of this study was to evaluate and compare the accuracy of the two methods.<p></p> Materials and methods: Pre-operative and 6 months post-operative cone beam CT scan (CBCT) images of 31 patients were randomly selected from the orthognathic patient database at the Dental Hospital and School, University of Glasgow, UK. Voxel based registration was performed on the DICOM images (Digital Imaging Communication in Medicine) using Maxilim software (Medicim-Medical Image Computing, Belgium). Surface based registration was performed on the soft and hard tissue 3D models using VRMesh (VirtualGrid, Bellevue City, WA). The accuracy of the superimposition was evaluated by measuring the mean value of the absolute distance between the two 3D image surfaces. The results were statistically analysed using a paired Student t-test, ANOVA with post-hoc Duncan test, a one sample t-test and Pearson correlation coefficient test.<p></p> Results: The results showed no significant statistical difference between the two superimposition methods (p<0.05). However surface based registration showed a high variability in the mean distances between the corresponding surfaces compared to voxel based registration, especially for soft tissue. Within each method there was a significant difference between superimposition of the soft and hard tissue models.<p></p> Conclusions: There were no significant statistical differences between the two registration methods and it was unlikely to have any clinical significance. Voxel based registration was associated with less variability. Registering on the soft tissue in isolation from the hard tissue may not be a true reflection of the surgical change

Accuracy of generic mesh conformation: the future of facial morphological analysis

Three-dimensional (3D) analysis of the face is required for the assessment of changes following surgery, to monitor the progress of pathological conditions and for the evaluation of facial growth. Sophisticated methods have been applied for the evaluation of facial morphology, the most common being dense surface correspondence. The method depends on the application of a mathematical facial mask known as the generic facial mesh for the evaluation of the characteristics of facial morphology. This study evaluated the accuracy of the conformation of generic mesh to the underlying facial morphology. The study was conducted on 10 non-patient volunteers. Thirty-four 2-mm-diameter self-adhesive, non-reflective markers were placed on each face. These were readily identifiable on the captured 3D facial image, which was captured by Di3D stereophotogrammetry. The markers helped in minimising digitisation errors during the conformation process. For each case, the face was captured six times: at rest and at the maximum movements of four facial expressions. The 3D facial image of each facial expression was analysed. Euclidean distances between the 19 corresponding landmarks on the conformed mesh and on the original 3D facial model provided a measure of the accuracy of the conformation process. For all facial expressions and all corresponding landmarks, these distances were between 0.7 and 1.7 mm. The absolute mean distances ranged from 0.73 to 1.74 mm. The mean absolute error of the conformation process was 1.13 ± 0.26 mm. The conformation of the generic facial mesh is accurate enough for clinical trial proved to be accurate enough for the analysis of the captured 3D facial images

DNA Vaccines Encoding Antigen Targeted to MHC Class II Induce Influenza-Specific CD8+ T Cell Responses, Enabling Faster Resolution of Influenza Disease

Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine induced protection. Whilst it is clear that antibodies play a protective role, vaccine induced CD8+ T cells can improve protection. To further explore the role of CD8+ T cells we used a DNA vaccine that encodes antigen dimerised to an immune cell targeting module. Immunising CB6F1 mice with the DNA vaccine in a heterologous prime boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared to protein alone. This improved disease resolution was dependent on CD8+ T cells. However, DNA vaccine regimes that induced CD8+ T cells alone were not protective and did not boost the protection provided by protein. The MHC targeting module used was an anti-I-Ed single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting we compared the response between BALB/c, C57BL/6 mice and an F1 cross of the two strains (CB6F1). BALB/c mice were protected, C57BL/6 were not and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines

Comparison of the Accuracy of Voxel Based Registration and Surface Based Registration for 3D Assessment of Surgical Change following Orthognathic Surgery

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Corrigendum: Airway T cells protect against RSV infection in the absence of antibody

Correction to: Mucosal Immunology (2018) 11, 249–256; doi:10.1038/mi.2017.46; published online 24 May 201

Comparative analysis of enzymatically produced novel linear DNA constructs with plasmids for use as DNA vaccines

The use of DNA to deliver vaccine antigens offers many advantages, including ease of manufacture and cost. However, most DNA vaccines are plasmids and must be grown in bacterial culture, necessitating elements which are either unnecessary for effective gene delivery (e.g. bacterial origins of replication) or undesirable (e.g. antibiotic resistance genes). Removing these elements may improve the safety profile of DNA for the delivery of vaccines. Here we describe a novel, double-stranded, linear DNA construct produced by an enzymatic process that solely encodes an antigen expression cassette, comprising antigen, promoter, polyA tail and telomeric ends. We compared these constructs (called ‘Doggybones’ because of their shape) with conventional plasmid DNA. Using luciferase-expressing constructs, we demonstrated that expression levels were equivalent between Doggybones and plasmids both in vitro and in vivo. When mice were immunized with DNA constructs expressing the HIV envelope protein gp140, equivalent humoral and cellular responses were induced. Immunizations with either construct type expressing haemagluttinin were protective against H1N1 influenza challenge. This is the first example of an effective DNA vaccine which can be produced on a large scale by enzymatic processes

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

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

OCT-guided Hyaloid Release for Vitreomacular Traction Syndrome

PURPOSE: To evaluate the usefulness of OCT retinal mapping in determining the configuration of a vitreomacular adhesion and selecting a meridian for entry into the subhyaloid space in patients with vitreomacular traction syndrome. METHODS: Six consecutive patients (6 eyes) with vitreomacular traction syndrome underwent vitrectomy with peeling of posterior hyaloid. Ocular coherence tomography (OCT) retinal mapping was performed preoperatively. Access to the subhyaloid space was made by creating an opening with a 25 gauge needle at a location where the detached posterior hyaloid membrane was farthest from the retinal surface. The location was selected based on six preoperative meridional OCT scans. The posterior hyaloid was then gently peeled off in a circular fashion around the fovea with a micropick. Visual acuity and foveal thicknesses were measured before the operation and 3 months afterwards. RESULTS: After the operation, visual acuity improved and central macular thicknesses were reduced significantly in all six patients. The best corrected visual acuity improved from 0.4 to 0.75 with a mean increase by 3.5 lines on a Snellen chart 3 months after the operation. The mean foveal thickness was reduced from 406 micrometer to 241 micrometer. The restoration of foveal pit was observed in five patients. Neither intraoperative nor postoperative complications were observed during the follow up period. CONCLUSIONS: An OCT retinal mapping program is a valuable diagnostic tool in understanding the configuration of vitreomacular adhesion and planning the surgical approach for operating on vitreomacular traction syndromeope