Magnetic resonance imaging of the third molars: developing a protocol suitable for age estimation

Purpose: To develop a clinically feasible MRI protocol – using standard commercial 3T MR hardware – to visualize all four third molars for age estimation, with particular attention to distinguishing the highest developmental stages. Materials and methods: In vivo scans of eight volunteers aged 17 – 24 years and ex vivo scans of porcine jaws were performed to make a stepwise selection of adequate sequences. A bilateral four-channel flexible surface head coil was used. The maximum acceptable acquisition time was set at seven minutes. Two observers evaluated the suitability of the images. Results: T2-weighted images were preferred to T1-weighted images. To clearly distinguish root apices in (almost) fully developed third molars a spatial resolution of 0.30 x 0.30 mm² was necessary. Within the limited acquisition time only a TSE T2 sequence generated images with sufficient resolution. Thin slice TSE T2 and TSE 3D T2 sequences could not generate the desired resolution. A UTE sequence was tried, but could not be completed in vivo by the used hardware. Conclusion: Three Tesla MRI of the third molars is a feasible technique for age estimation, in which a TSE T2 sequence can provide the desired spatial resolution within a clinically acceptable acquisition time

Magnetic resonance imaging of third molars : developing a protocol suitable for forensic age estimation

Background: Established dental age estimation methods in sub-adults study the development of third molar root apices on radiographs. In living individuals, however, avoiding ionising radiation is expedient. Studying dental development with magnetic resonance imaging complies with this requirement, adding the advantage of imaging in three dimensions. Aim: To elaborate the development of an MRI protocol to visualise all third molars for forensic age estimation, with particular attention to the development of the root apex. Subjects and methods:Ex vivo scans of porcine jaws and in vivo scans of 10 volunteers aged 17-25 years were performed to select adequate sequences. Studied parameters were T1 vs T2 weighting, ultrashort echo time (UTE), fat suppression, in plane resolution, slice thickness, 3D imaging, signal-to-noise ratio, and acquisition time. A bilateral four-channel flexible surface coil was used. Two observers evaluated the suitability of the images. Results: T2-weighted images were preferred to T1-weighted images. To clearly distinguish root apices in (almost) fully developed third molars an in plane resolution of 0.33 x 0.33 mm(2) was deemed necessary. Taking acquisition time limits into account, only a T2 FSE sequence with slice thickness of 2 mm generated images with sufficient resolution and contrast. UTE, thinner slice T2 FSE and T2 3D FSE sequences could not generate the desired resolution within 6.5 minutes. Conclusion: Three Tesla MRI of the third molars is a feasible technique for forensic age estimation, in which a T2 FSE sequence can provide the desired in plane resolution within a clinically acceptable acquisition time

Third molar MRI in Forensic Age Estimation: protocol Development and considerations for use

Established dental age estimation methods in sub-adults mainly study the development of third molar root apices on radiographs.1,2 In living individuals, however, avoiding ionizing radiation is expedient. Studying dental development with magnetic resonance imaging (MRI) complies with this requirement, adding the advantage of imaging in three dimensions. Several studies investigated the use of MRI for dental age estimation.3-5 However, none of these studies discussed the differences between staging on radiographs and on MRI. Firstly, this study aims to elaborate the development of a 3 Tesla MRI protocol to visualize all third molar positions for forensic age estimation. Particular attention will be given to the development of the third molar root apices.6 Secondly, this study aims to prospectively study root stage assessment of third molars using MRI. In order to provide considerations for 2D staging into 3D staging, MRI will be compared with panoramic radiographs.7 To develop a clinically feasible MRI protocol visualizing all third molars for age estimation, ex vivo scans of porcine jaws and in vivo scans of ten volunteers aged 17-25 years were performed. Studied parameters were T1 versus T2 weighting, ultrashort echo time (UTE), fat suppression, in plane resolution, slice thickness, 3D imaging, signal-to-noise ratio, and acquisition time. A bilateral four-channel flexible surface coil was used. Two observers evaluated the suitability of the images. To compare third molar staging on MRI with staging on panoramic radiographs, all third molars were evaluated in 16 participants aged between 14 and 26 years. Three staging techniques were studied by two observers.8-10 T2-weighted images were preferred to T1-weighted images. To clearly distinguish root apices in (almost) fully developed third molars an in plane resolution of 0.33 x 0.33 mm² was deemed necessary. Taking acquisition time limits into account, only a T2 FSE sequence with slice thickness of 2mm generated images with sufficient resolution and contrast. UTE, thinner slice T2 FSE and T2 3D FSE sequences could not generate the desired resolution within 6.5 minutes. Lower third molars were equally assessable on both imaging techniques (93.8% MRI, 98.4% radiograph). Upper third molars were more difficult to evaluate on radiographs than on MRI (96.9% MRI, 43% radiograph). Inter- and intra-observer agreement for staging was higher in MRI than in radiographs. In both imaging techniques lower third molar staging showed higher inter- and intra observer agreement compared to upper third molar staging. MR images in the sagittal plane proved to be essential for third molar staging. Most decisive roots were the palatal in upper third molars and the distal in lower third molars. Three Tesla MRI of the third molars is a feasible technique for age estimation, in which a T2 FSE sequence can provide the desired in plane resolution within a clinically acceptable Proposal Id: 170949 Short Title: Third Molar MRI in Forensic Age Estimation [For Reference Purposes acquisition time. Several considerations are necessary to transfer known radiographical 2D staging methods to this 3D MRI application.status: publishe

"Unforgettable" - a pictorial essay on anatomy and pathology of the hippocampus

The hippocampus is a small but complex anatomical structure that plays an important role in spatial and episodic memory. The hippocampus can be affected by a wide range of congenital variants and degenerative, inflammatory, vascular, tumoral and toxic-metabolic pathologies. Magnetic resonance imaging is the preferred imaging technique for evaluating the hippocampus. The main indications requiring tailored imaging sequences of the hippocampus are medically refractory epilepsy and dementia. The purpose of this pictorial review is threefold: (1) to review the normal anatomy of the hippocampus on MRI; (2) to discuss the optimal imaging strategy for the evaluation of the hippocampus; and (3) to present a pictorial overview of the most common anatomic variants and pathologic conditions affecting the hippocampus

Tumor-infiltrating lymphocytes and PD-L1 expression in pleomorphic lobular breast carcinoma

Background: The prognostic and predictive role of stromal tumor-infiltrating lymphocytes (sTILs) is undetermined in pleomorphic invasive lobular cancer (pILC). The same applies for the expression of PD-1/PD-L1 in this rare breast cancer subtype. Here, we aimed to investigate the expression of sTILs and analyze the PD-L1 expression levels in pILC. Methods: Archival tissues from sixty-six patients with pILC were collected. The sTIL density was scored as a percentage of tumor area using the following cut-offs: 0%; <5%; 5-9%; and 10-50%. The PD-L1 expression was analyzed using IHC on formalin-fixed, paraffin-embedded tissue sections using SP142 and 22C3 antibodies. Results: A total of 82% of the sixty-six patients were hormone receptor positive and 8% of cases were triple negative (TN), while 10% showed human epidermal growth factor receptor 2 (HER2) amplification. sTILs (=1%) were present in 64% of the study population. Using the SP142 antibody, 36% of tumors demonstrated a positive PD-L1 score of =1%, and using the 22C3 antibody, 28% had a positive PD-L1 score of =1. There was no correlation between sTILs or PD-L1 expression and tumor size, tumor grade, nodal status, expression of estrogen receptor (ER), or amplification of HER2. Our data did not show any difference in survival between the three molecular subtypes of pILC with respect to sTILs and PD-L1 expression. Conclusion: This study shows that pILCs show some degree of sTILs and PD-L1 expression; however, this was not associated with a survival improvement. Additional large trials are needed to understand immune infiltration in lobular cancer, especially in the pleomorphic subtype

Strategies and performance of the CMS silicon tracker alignment during LHC Run 2

The strategies for and the performance of the CMS silicon tracking system alignment during the 2015–2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios

Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally

The surgical safety checklist and patient outcomes after surgery: a prospective observational cohort study, systematic review and meta-analysis

© 2017 British Journal of Anaesthesia Background: The surgical safety checklist is widely used to improve the quality of perioperative care. However, clinicians continue to debate the clinical effectiveness of this tool. Methods: Prospective analysis of data from the International Surgical Outcomes Study (ISOS), an international observational study of elective in-patient surgery, accompanied by a systematic review and meta-analysis of published literature. The exposure was surgical safety checklist use. The primary outcome was in-hospital mortality and the secondary outcome was postoperative complications. In the ISOS cohort, a multivariable multi-level generalized linear model was used to test associations. To further contextualise these findings, we included the results from the ISOS cohort in a meta-analysis. Results are reported as odds ratios (OR) with 95% confidence intervals. Results: We included 44 814 patients from 497 hospitals in 27 countries in the ISOS analysis. There were 40 245 (89.8%) patients exposed to the checklist, whilst 7508 (16.8%) sustained ≥1 postoperative complications and 207 (0.5%) died before hospital discharge. Checklist exposure was associated with reduced mortality [odds ratio (OR) 0.49 (0.32–0.77); P\u3c0.01], but no difference in complication rates [OR 1.02 (0.88–1.19); P=0.75]. In a systematic review, we screened 3732 records and identified 11 eligible studies of 453 292 patients including the ISOS cohort. Checklist exposure was associated with both reduced postoperative mortality [OR 0.75 (0.62–0.92); P\u3c0.01; I2=87%] and reduced complication rates [OR 0.73 (0.61–0.88); P\u3c0.01; I2=89%). Conclusions: Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine