Image guided critical screw placement precision in the cervical spine : important or incidental? : results of a series of 91 consecutive cases using OVEM

Study design: A retrospective study of image guided cervical implant placement precision. Objective: To describe a simple and precise classification of cervical critical screw placement. Summary of Background Data: "Critical" screw placement is defined as implant insertion into a bone corridor which is surrounded circumferentially by neurovascular structures. While the use of image guidance has improved accuracy, there is currently no classification which provides sufficient precision to assess the navigation success of critical cervical screw placement. Methods: Based on postoperative clinical evaluation and CT imaging, the orthogonal view evaluation method (OVEM) is used to classify screw accuracy into grade I (no cortical breach), grade la (screw thread cortical breach), grade II (internal diameter cortical breach) and grade III (major cortical breach causing neural or vascular injury). Grades II and III are considered to be navigation failures, after accounting for bone corridor / screw mismatch (minimal diameter of targeted bone corridor being smaller than an outer screw diameter). Results: A total of 276 screws from 91 patients were classified into grade I (64.9%), grade la (18.1%), and grade II (17.0%). No grade III screw was observed. The overall rate of navigation failure was 13%. Multiple logistic regression indicated that navigational failure was significantly associated with the level of instrumentation and the navigation system used. Navigational failure was rare (1.6%) when the margin around the screw in the bone corridor was larger than 1.5 mm. Conclusions: OVEM evaluation appears to be a useful tool to assess the precision of critical screw placement in the cervical spine. The OVEM validity and reliability need to be addressed. Further correlation with clinical outcomes will be addressed in future studies.

Registre du Saint Office de Rome, contenant plusieurs procès en matière de foi. Au f. 308, procès fait à ceux qui gardaient l'image de Henri IV.

Acquis le 27 juin 1856 de M. Benjamin Duprat, libraire, pour le prix de 70 francs; cf. B.n.F., département des Manuscrits, registre des acquisitions 1848-1893, n° 5041 "Registre original du Saint-Office de Rome, contenant les procédures de 1589 à 1595, in fol. pap."

L'Image du monde, en vers, rédaction non interpolée, attribuée à GAUTIER DE METZ ; dit de l'Unicorne.

Contient : « Cel livre de clergie en romans, qui est appellez l'image du monde, contient LV chappittres et XXVIII figures... » ; « Prologue. Qui bien veult entendre ce livre Et savoir comment il doit vivre... » ; « ... Qui par cestui poez aprendre Qui du ciecle volez entendre, Quel chose et comment ce est, Et comment va et comment nest. » — Au bas de la première colonne du même feuillet, on lit : « En l'an de l'incarnacion Aus roys de la paricion MCC XLV anz, Fu premier parfait cilz rommanz. » La même date est rapportée aux feuillets 54 v°, col. 2-55 r°, col. 1 ; « Cy commence ly rommans qui est appelez l'Unicorne, qui parle de la mort et de la vie par semblence de l'arbre. » Cette copie est incomplète des 12 premiers vers ; le début est ici : « [J]e vous vuil commencer un conte De convoitise qui surmonte... » ; « ... Amen. Que Dieux nous doint pardon. Ce fenist le Unicorne »

Image du monde de GAUTIER DE METZ et Histoire du Saint Graal.

Contient : I Image du monde, poème de GAUTIER DE METZ ; II

« L'Image dou monde » [par GAUTIER DE METZ].

Commençant par : « Or prions au commencement A Dieu le Pere omnipotent... » et finissant par : « Quel chose et comment il va, Toujourz sanz fin est et sera. Explicit Mapemonde » .

Recueil de traités de médecine et Image du monde.

Contient : Recueil de recettes médicales, de Jean Picart, Jean de Chalon, Jean d'Aunoy, etc., précédé d'un prologue, qui débute : « Tres noble et poissant prince mons. Charle, conte de Valoys, de Chartres, d'Alenchon et d'Anjou, fist faire cest livret, qui est bon et profitable pour gairir toutes manieres de plaies vielles et nouvelles, et pour aucunes autres maladies aussi » ; « Livre de Clergie en romans, qui est appelée l'Image du monde, » par GAUTIER DE METZ. — Rédaction non interpolée ; ALEBRAND de Florence, Régime du corps ; divisé en quatre livres, incomplet du premier feuillet, qui contenait la préface ; « Traictié que les maistres de medicine et les astronomiens de Paris firent de la pestilence, que fisique apelle epydimie, en l'an de l'incarnation Nostre Seignieur MCCCXLVIII, au mandement de tres noble et trespoissant prince le roi de France, pour cause de la tres grant et tres merveilleuse epydimie, qui lors couroit par son royaume. — Veus et considérés les effets merveilleus desquels la cause est tapie... » (Traduction de la Consultation latine, publiée par M. J. Michon en 1860 et par M. É. Rébouis en 1888)

GAUTIER DE METZ, Image du monde.

Contient : Mappemonde peinte ; « Bestiaires, » poème de GUILLAUME LE CLERG ; « Lapidaires » de MARBODE, traduction en vers par GUILLAUME LE CLERC (ms. A de L. Pannier)

Anvers, Rudd [non visible sur l'image] gagne [la] finale du 400 m [des Jeux olympiques, seuls apparaissent les coureurs Ainsworth, Shea et Dafel, 20/8/20] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 60650

Confocal and two-photon microscopy : image enhancement /

Confocal and two-photon microcopy have become essential tools in biological research and today many investigations are not possible without their help. The valuable advantage that these two techniques offer is the ability of optical sectioning. Optical sectioning makes it possible to obtain 3D visuahzation of the structiu-es, and hence, valuable information of the structural relationships, the geometrical, and the morphological aspects of the specimen. The achievable lateral and axial resolutions by confocal and two-photon microscopy, similar to other optical imaging systems, are both defined by the diffraction theorem. Any aberration and imperfection present during the imaging results in broadening of the calculated theoretical resolution, blurring, geometrical distortions in the acquired images that interfere with the analysis of the structures, and lower the collected fluorescence from the specimen. The aberrations may have different causes and they can be classified by their sources such as specimen-induced aberrations, optics-induced aberrations, illumination aberrations, and misalignment aberrations. This thesis presents an investigation and study of image enhancement. The goal of this thesis was approached in two different directions. Initially, we investigated the sources of the imperfections. We propose methods to eliminate or minimize aberrations introduced during the image acquisition by optimizing the acquisition conditions. The impact on the resolution as a result of using a coverslip the thickness of which is mismatched with the one that the objective lens is designed for was shown and a novel technique was introduced in order to define the proper value on the correction collar of the lens. The amoimt of spherical aberration with regard to t he numerical aperture of the objective lens was investigated and it was shown that, based on the purpose of our imaging tasks, different numerical apertures must be used. The deformed beam cross section of the single-photon excitation source was corrected and the enhancement of the resolution and image quaUty was shown. Furthermore, the dependency of the scattered light on the excitation wavelength was shown empirically. In the second part, we continued the study of the image enhancement process by deconvolution techniques. Although deconvolution algorithms are used widely to improve the quality of the images, how well a deconvolution algorithm responds highly depends on the point spread function (PSF) of the imaging system applied to the algorithm and the level of its accuracy. We investigated approaches that can be done in order to obtain more precise PSF. Novel methods to improve the pattern of the PSF and reduce the noise are proposed. Furthermore, multiple soiu'ces to extract the PSFs of the imaging system are introduced and the empirical deconvolution results by using each of these PSFs are compared together. The results confirm that a greater improvement attained by applying the in situ PSF during the deconvolution process.