Normative MR Cervical Spinal Canal Dimensions

Purpose To provide normal values of the cervical spinal canal and spinal cord dimensions in several planes with respect to spinal level, age, sex, and body height. Materials and Methods This study was approved by the institutional review board; all individuals provided signed informed consent. In a prospective multicenter study, two blinded raters independently examined cervical spine magnetic resonance (MR) images of 140 healthy volunteers who were white. The midsagittal diameters and areas of spinal canal and spinal cord, respectively, were measured at the midvertebral levels of C1, C3, and C6. A multivariate general linear model described the influence of sex, body height, age, and spinal level on the measured values. Results There were differences for sex, spinal level, interaction between sex and level, and body height, while age had significant yet limited influence. Normative ranges for the sagittal diameters and areas of spinal canal and spinal cord were defined at C1, C3, and C6 levels for men and women. In addition to a calculation of normative ranges for a specific sex, spinal level, age, and body height data, data for three different height subgroups at 45 years of age were extracted. These results show a range of the spinal canal dimensions at C1 (from 10.7 to 19.7 mm), C3 (from 9.4 to 17.2 mm), and C6 (from 9.2 to 16.8 mm) levels. Conclusion : The dimensions of the cervical spinal canal and cord in healthy individuals are associated with spinal level, sex, age, and height. © RSNA, 2013 Online supplemental material is available for this article.

Risk factors for anal cancer in persons infected with HIV: a nested case-control study in the Swiss HIV Cohort Study

Although persons infected with human immunodeficiency virus (HIV), particularly men who have sex with men, are at excess risk for anal cancer, it has been difficult to disentangle the influences of anal exposure to human papillomavirus (HPV) infection, immunodeficiency, and combined antiretroviral therapy. A case-control study that included 59 anal cancer cases and 295 individually matched controls was nested in the Swiss HIV Cohort Study (1988-2011). In a subset of 41 cases and 114 controls, HPV antibodies were tested. A majority of anal cancer cases (73%) were men who have sex with men. Current smoking was significantly associated with anal cancer (odds ratio (OR) = 2.59, 95% confidence interval (CI): 1.25, 5.34), as were antibodies against L1 (OR = 4.52, 95% CI: 2.00, 10.20) and E6 (OR = ∞, 95% CI: 4.64, ∞) of HPV16, as well as low CD4+ cell counts, whether measured at nadir (OR per 100-cell/μL decrease = 1.53, 95% CI: 1.18, 2.00) or at cancer diagnosis (OR per 100-cell/μL decrease = 1.24, 95% CI: 1.08, 1.42). However, the influence of CD4+ cell counts appeared to be strongest 6-7 years prior to anal cancer diagnosis (OR for <200 vs. ≥500 cells/μL = 14.0, 95% CI: 3.85, 50.9). Smoking cessation and avoidance of even moderate levels of immunosuppression appear to be important in reducing long-term anal cancer risks.

Frameless linac-based (Novalis TX) stereotactic treatment for vestibular schwannoma that extend distally into the iac (Internal Acoustic Canal): an analysis of the dose to the cochlea

Objectives: We compare the dose parameters between 3 different radiosurgery delivery techniques which may have an impact on cochlea function. Methods: Five patients with unilateral vestibular schwannoma (VS) were selected for this study. Planning procedure was carried out using the BrainLAB® iPlan planning system v. 4.5. For each patient three different planning techniques were used: dynamic arc (DA) with 5 arcs per plan, hybrid arc (HA) with 5 arcs per plan and IMRT with 8 fields per plan. For each technique, two plans were generated with different methods: with the first method (PTV coverage) it was the goal to fully cover the PTV with at least 12 Gy (normalization: 12 Gy covered 99% of the PTV) and with the second method (cochlea sparing) it was the goal to spare the cochlea (normalization: 12 Gy covers 50% of the PTV/V4Gy of cochlea lower than 1%). Plan evaluation was done considering target volume and coverage (conformity and homogeneity) and OAR constraints (mean (Dmean) and maximum dose (Dmax) to cochlea, Dmax to brainstem and cochlea). The total number of monitor units (MU) was analyzed. Results: The median tumor volume was 0.95 cm³ (range, 0.86-3 cm³). The median PTV was 1.44 cm³ (range, 1-3.5 cm³). The median distance between the tumor and the cochlea's modiulus was 2.7 mm (range, 1.8-6.3 mm). For the PTV coverage method, when we compared the cochlear dose in VS patients planned with DA, HA and IMRT, there were no significant differences in Dmax (p = 0.872) and in Dmean (p= 0.860). We found a significant correlation (p< 0.05) between the target volume and the cochlear Dmean for all plans with Pearson's coefficient correlation of 0.90, 0.92 and 0.94 for the DA, HA and IMRT techniques, respectively. For the cochlea sparing method, when we compared the cochlear dose in VS patients planned with DA, HA and IMRT, there were no significant differences in Dmax (p = 0.310) and in Dmean (p= 0.275). However, in this group the V4Gy of the ipsilateral cochlea represents less than 1%. When using the HA or IMRT technique, the homogeneity and conformity in the PTV, but also the number of MUs were increased in comparison to the DA technique. Conclusion: VS tumors that extend distally into the IAC had an equivalent sparing of cochlea with DA approach compared with the HA and IMRT techniques. Disclosure: No significant relationships.

[Anal metastasis from a lung cancer]

We report an anal metastasis from a lung cancer which was diagnosed on symptoms mimicking an acute anal abcess. The diagnosis was based on specific immunohistochemistry.

Three-dimensional study of nasopalatine canal morphology: a descriptive retrospective analysis using cone-beam computed tomography

PURPOSE For dental implant treatment planning and placement, a precise anatomic description of the nasopalatine canal (NC) is necessary. This descriptive retrospective study evaluated dimensions of the NC and buccal bone plate (BBP) and the tridimensional association of the anatomic variants of NC, using cone-beam computed tomography (CBCT). METHODS This study included 230 CBCTs. Sagittal slices were used for measurements of the NC and BBP and to evaluate shape and direction-course of the NC. Coronal slices were used to assess NC shape and axial slices to assess number of incisive foramina and foramina of Stenson. RESULTS Mean NC length was 12.34 ± 2.79 mm, statistically significant differences were detected between genders (p < 0.001). Mean BBP length was 20.87 ± 3.68 mm, statistically significant differences were found for the dental status (p < 0.001) and mean BBP width was 6.83 ± 1.28 mm, significant differences were detected between genders (p < 0.001). Mean nasopalatine angle was 73.33° ± 8.11°, significant differences were found in sagittal and coronal classifications. The most prevalent canal was: cylindrical sagittal shape (48.2 %); slanted-straight direction-course (57.6 %); Ya-type coronal shape (42.4 %); and one foramen incisive with two Stenson's foramina (1-2) (50.9 %). Sagittal shape was associated with sagittal direction-course (p < 0.001). Coronal shape was associated with axial classification (p < 0.001). CONCLUSIONS The NC anatomy is highly variable. Gender is related to the NC length and BBP width, while dental status is related to BBP length. There was an association between the different sagittal classifications of the NC and between the coronal shape and axial classification.

A novel animal model for external anal sphincter insufficiency

Abstract PURPOSE: Reliable animal models are essential to evaluate future therapeutic options like cell-based therapies for external anal sphincter insufficiency. The goal of our study was to describe the most reliable model for external sphincter muscle insufficiency by comparing three different methods to create sphincter muscle damage. METHODS: In an experimental animal study, female Lewis rats (200-250 g) were randomly assigned to three treatment groups (n = 5, each group). The external sphincter muscle was weakened in the left dorsal quadrant by microsurgical excision, cryosurgery, or electrocoagulation by diathermy. Functional evaluation included in vivo measurements of resting pressure, spontaneous muscle contraction, and contraction in response to electrical stimulation of the afferent nerve at baseline and at 2, 4, and 6 weeks after sphincter injury. Masson's trichrome staining and immunofluorescence for skeletal muscle markers was performed for morphological analysis. RESULTS: Peak contraction after electrical stimulation was significantly decreased after sphincter injury in all groups. Contraction forces recovered partially after cryosurgery and electrocoagulation but not after microsurgical excision. Morphological analysis revealed an incomplete destruction of the external sphincter muscle in the cryosurgery and electrocoagulation groups compared to the microsurgery group. CONCLUSIONS: For the first time, three different models of external sphincter muscle insufficiency were directly compared. The animal model using microsurgical sphincter destruction offers the highest level of consistency regarding tissue damage and sphincter insufficiency, and therefore represents the most reliable model to evaluate future therapeutic options. In addition, this study represents a novel model to specifically test the external sphincter muscle function.

Retention of Root Canal Posts: Effect of Cement Film Thickness, Luting Cement, and Post Pretreatment.

The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement, pretreatment with tribochemical silicate coating significantly increased retention of the posts. Increased cement film thickness resulted in decreased retention of untreated posts and of pretreated posts luted with zinc phosphate cement. Increased cement film thickness had no influence on retention of pretreated posts luted with resin cement. Thus, retention of the posts was influenced by the type of luting cement, by the cement film thickness, and by the post pretreatment.

Influence of root canal disinfectants on growth factor release from dentin

INTRODUCTION During dentinogenesis, growth factors become entrapped in the dentin matrix that can later be released by demineralization. Their effect on pulpal stem cell migration, proliferation, and differentiation could be beneficial for regenerative endodontic therapies. However, precondition for success, as for conventional root canal treatment, will be sufficient disinfection of the root canal system. Various irrigation solutions and intracanal dressings are available for clinical use. The aim of this study was 2-fold: to identify a demineralizing solution suitable for growth factor release directly from dentin and to evaluate whether commonly used disinfectants for endodontic treatment will compromise this effect. METHODS Dentin disks were prepared from extracted human teeth and treated with EDTA or citric acid at different concentrations or pH for different exposure periods. The amount of transforming growth factor-β1 (TGF-β1), fibroblast growth factor 2, and vascular endothelial growth factor were quantified via enzyme-linked immunosorbent assay and visualized by gold labeling. Subsequently, different irrigation solutions (5.25% sodium hypochloride, 0.12% chlorhexidine digluconate) and intracanal dressings (corticoid-antibiotic paste, calcium hydroxide: water-based and oil-based, triple antibiotic paste, chlorhexidine gel) were tested, and the release of TGF-β1 was measured after a subsequent conditioning step with EDTA. RESULTS Conditioning with 10% EDTA at pH 7 rendered the highest amounts of TGF-β1 among all test solutions. Fibroblast growth factor 2 and vascular endothelial growth factor were detected after EDTA conditioning at minute concentrations. Irrigation with chlorhexidine before EDTA conditioning increased TGF-β1 release; sodium hypochloride had the opposite effect. All tested intracanal dressings interfered with TGF-β1 release except water-based calcium hydroxide. CONCLUSIONS Growth factors can be released directly from dentin via EDTA conditioning. The use of disinfecting solutions or medicaments can amplify or attenuate this effect.

Accuracy of conventional radiography and computed tomography in predicting implant position in relation to the vertebral canal in dogs.

OBJECTIVE To compare the accuracy of radiography and computed tomography (CT) in predicting implant position in relation to the vertebral canal in the cervical and thoracolumbar vertebral column. STUDY DESIGN In vitro imaging and anatomic study. ANIMALS Medium-sized canine cadaver vertebral columns (n=12). METHODS Steinmann pins were inserted into cervical and thoracolumbar vertebrae based on established landmarks but without predetermination of vertebral canal violation. Radiographs and CT images were obtained and evaluated by 6 individuals. A random subset of pins was evaluated for ability to distinguish left from right pins on radiographs. The ability to correctly identify vertebral canal penetration for all pins was assessed both on radiographs and CT. Spines were then anatomically prepared and visual examination of pin penetration into the canal served as the gold standard. RESULTS Left/right accuracy was 93.1%. Overall sensitivity of radiographs and CT to detect vertebral canal penetration by an implant were significantly different and estimated as 50.7% and 93.4%, respectively (P<.0001). Sensitivity was significantly higher for complete versus partial penetration and for radiologists compared with nonradiologists for both imaging modalities. Overall specificity of radiographs and CT to detect vertebral canal penetration was 82.9% and 86.4%, respectively (P=.049). CONCLUSIONS CT was superior to radiographic assessment and is the recommended imaging modality to assess penetration into the vertebral canal. CLINICAL RELEVANCE CT is significantly more accurate in identifying vertebral canal violation by Steinmann pins and should be performed postoperatively to assess implant position.

Effect of tympanic cavity evacuation and flushing on microbial isolates during total ear canal ablation with lateral bulla osteotomy in dogs.

OBJECTIVE To evaluate differences in bacterial numbers, identity, and susceptibility in samples obtained from the tympanic cavity on entry (preflush) and after evacuation and lavage (postflush) and assess perioperative and empiric antimicrobial selection in dogs that underwent total ear canal ablation (TECA) with lateral bulla osteotomy (LBO) or reoperation LBO. DESIGN Prospective clinical study. ANIMALS 34 dogs. PROCEDURE TECA with LBO or reoperation LBO was performed on 47 ears. Pre- and postflush aerobic and anaerobic samples were obtained from the tympanic cavity. Isolates and antimicrobial susceptibility patterns were compared. RESULTS Different isolates (31/44 [70%] ears) and susceptibility patterns of isolate pairs (6/44 [14%] ears) were detected in pre- and postflush samples from 84% of ears. Evacuation and lavage of the tympanic cavity decreased the number of bacterial isolates by 33%. In 26% of ears, bacteria were isolated from post-flush samples but not preflush samples. Only 26% of isolates tested were susceptible to cefazolin. At least 1 isolate from 53% of dogs that received empirically chosen antimicrobials postoperatively was resistant to the selected drugs. Anaerobic bacteria were recovered from 6 ears. CONCLUSIONS AND CLINICAL RELEVANCE Accurate microbiologic assessment of the tympanic cavity should be the basis for selection of antimicrobials in dogs undergoing TECA with LBO. Bacteria remain in the tympanic cavity after evacuation and lavage. Cefazolin was a poor choice for dogs that underwent TECA with LBO, as judged on the basis of culture and susceptibility testing results.

Patient outcomes after laminotomy, hemilaminectomy, laminectomy and laminectomy with instrumented fusion for spinal canal stenosis: a propensity score-based study from the Spine Tango registry.

PURPOSE To compare patient outcomes and complication rates after different decompression techniques or instrumented fusion (IF) in lumbar spinal stenosis (LSS). METHODS The multicentre study was based on Spine Tango data. Inclusion criteria were LSS with a posterior decompression and pre- and postoperative COMI assessment between 3 and 24 months. 1,176 cases were assigned to four groups: (1) laminotomy (n = 642), (2) hemilaminectomy (n = 196), (3) laminectomy (n = 230) and (4) laminectomy combined with an IF (n = 108). Clinical outcomes were achievement of minimum relevant change in COMI back and leg pain and COMI score (2.2 points), surgical and general complications, measures taken due to complications, and reintervention on the index level based on patient information. The inverse propensity score weighting method was used for adjustment. RESULTS Laminotomy, hemilaminectomy and laminectomy were significantly less beneficial than laminectomy in combination with IF regarding leg pain (ORs with 95% CI 0.52, 0.34-0.81; 0.25, 0.15-0.41; 0.44, 0.27-0.72, respectively) and COMI score improvement (ORs with 95% CI 0.51, 0.33-0.81; 0.30, 0.18-0.51; 0.48, 0.29-0.79, respectively). However, the sole decompressions caused significantly fewer surgical (ORs with 95% CI 0.42, 0.26-0.69; 0.33, 0.17-0.63; 0.39, 0.21-0.71, respectively) and general complications (ORs with 95% CI 0.11, 0.04-0.29; 0.03, 0.003-0.41; 0.25, 0.09-0.71, respectively) than laminectomy in combination with IF. Accordingly, the likelihood of required measures was also significantly lower after laminotomy (OR 0.28, 95% CI 0.17-0.46), hemilaminectomy (OR 0.28, 95% CI 0.15-0.53) and after laminectomy (OR 0.39, 95% CI 0.22-0.68) in comparison with laminectomy with IF. The likelihood of a reintervention was not significantly different between the treatment groups. DISCUSSION As already demonstrated in the literature, decompression in patients with LSS is a very effective treatment. Despite better patient outcomes after laminectomy in combination with IF, caution is advised due to higher rates of surgical and general complications and consequent required measures. Based on the current study, laminotomy or laminectomy, rather than hemilaminectomy, is recommendable for minimum relevant pain relief.