Impact of previous statin use on first intracerebral hemorrhage in cerebral amyloid angiopathy.

OBJECTIVES: Statins have been associated with an increased risk of spontaneous intracerebral hemorrhage (ICH), but without dedicated study in cerebral amyloid angiopathy (CAA). We aimed to evaluate the association between previous statin treatment and radiological hemorrhagic lesions in a CAA population during a first lobar ICH event. MATERIALS AND METHODS: We retrospectively included all patients meeting the modified Boston criteria for probable CAA and admitted for a first lobar ICH between 2010 and 2021 at Rouen University Hospital. Patients were classified as having previous statin treatment or not. We compared the ICH volume, the number of associated cerebral microbleeds (CMBs), and cortical superficial siderosis (CSS) according to previous statin treatment or not. We also compared functional outcomes and ICH recurrence during the follow-up period between the two groups. RESULTS: We included 99 patients, 27 of whom had statin treatment prior to their ICH. The ICH volume and the number of CMBs did not differ between groups. Disseminated CSS was initially more frequent in the statin group (88% versus 57%; P=0.019), but this was no longer significant after adjustment for antiplatelet treatment (P=0.13). The long-term outcome was similar between the two groups with no increased risk of ICH recurrence in the statin-treated group (29.63% versus 23.61%, P=0.54). CONCLUSIONS: Previous statin treatment was not associated with more severe hemorrhagic lesions in CAA in terms of ICH volume or number of microbleeds, but a trend for increased disseminated CSS was highlighted, which will require further larger studies.

Assessment of hydro-saline retention in bullous pemphigoid patients treated with super-potent topical corticosteroids.

INTRODUCTION: Super-potent topical corticosteroids (CS) are the mainstay of treatment for bullous pemphigoid. Since super-potent topical CS have systemic effects due to their transcutaneous absorption, we assessed whether super-potent CS were responsible for hydro-saline retention (HSR) in bullous pemphigoid patients. PATIENTS AND METHODS: From 2015 to 2017, patients with newly-diagnosed bullous pemphigoid treated using clobetasol propionate cream at a starting daily dose of 20 to 40 g were subsequently included in a prospective study. HSR was assessed by longitudinally measuring extracellular water (ECW) volume using bioimpedance analysis (BodyStat QuadScan 4000®) from Day 0 to Day 30 after the initiation of topical CS. Other parameters related to HSR such as weight, blood pressure, natriuresis and proteinuria, were also recorded. RESULTS: Twenty-nine patients (14 men and 15 women) of mean age 81.8 ±â€¯9.3 years were included and analysed. The mean ECW volume decreased from Day 0 to Day 7 (18.1 ±â€¯4.2 vs 16.7 ±â€¯2.7, p = 0.0094) and was maintained from Day 7 to Day 30 (16.8 ±â€¯2.8 vs 17.0 ±â€¯3.4 L; p = 0.8040). Patient weight loss at Day 30 (69.9 ±â€¯13.6 vs 72.5 ±â€¯14.2 kg, p = 0.0085) was closely correlated with the decrease in ECW volume (r = 0.6740, p < 0.0001). No significant changes in natriuresis, 24-hour proteinuria or blood pressure were observed from Day 0 to Day 30. CONCLUSION: We found no evidence of HSR in bullous pemphigoid patients treated with super-potent topical CS. Conversely, ECW volume decreased from Day 0 to Day 30, which was correlated with patient weight loss.

Follow-up of Intracranial Aneurysms Treated by Flow Diverters: Evaluation of Parent Artery Patency Using 3D-T1 Gradient Recalled-Echo Imaging with 2-Point Dixon in Combination with 3D-TOF-MRA with Compressed Sensing.

BACKGROUND AND PURPOSE: MRA assessment of parent artery patency after flow-diverter placement is complicated by imaging artifacts produced by these devices. The purpose of this study was to assess the accuracy of liver acquisition with volume acceleration-flex technique (LAVA-Flex) MRA in combination with 3D-TOF with HyperSense MRA for the evaluation of parent vessel status after intracranial flow-diverter placement. MATERIALS AND METHODS: Fifty-six patients treated by flow diversion and followed with both DSA and 3T MRA between November 2020 and August 2021 were included. All patients were evaluated for parent artery patency using the same imaging protocol (DSA, noncontrast MRA including 3D-TOF with HyperSense and LAVA-Flex, and contrast-enhanced MRA, including time-resolved imaging of contrast kinetics MRA and delayed contrast-enhanced MRA). RESULTS: With DSA as a criterion standard to evaluate the patency of the parent vessel, noncontrast MRA had a good specificity (0.83) and positive predictive value (0.65), better than contrast-enhanced MRA (0.55 and 0.41, respectively). Both had excellent sensitivity and negative predictive value: noncontrast MRA, 0.93 and 0.97, respectively; contrast-enhanced MRA, 0.93 and 0.96, respectively. Specificity and positive predictive value tended to be lower for patients treated with additional devices than for those treated with flow diverters exclusively and for patients treated with a specific type of flow diverter. CONCLUSIONS: Noncontrast MRA can be used for noninvasive follow-up of intracranial aneurysms treated by flow diverters. The combined use of LAVA-Flex and 3D-TOF with HyperSense sequences allows monitoring the status of the parent artery and aneurysm occlusion.

[Identification of factors associated with performance in objective structured clinical examination in Rouen medical school]. / Identification des facteurs associés à la réussite aux examens cliniques objectifs et structurés dans la faculté de médecine de Rouen.

CONTEXT: Objective structured clinical examination (OSCE) became a national exam at the end of medical studies in France. The aim of this study was to identify the predictive factors for success at OSCEs. METHODS: Aurvey query after the OSCEs was completed by fifth-year medicine students at Rouen Uuniversity.. Data on continuous variables were compared using the Mann-Whitney test. Data on quantitative variables were compared using the Spearman's correlation. RESULTS: Two hundred and thirty-nine students, i.e., 98.7 % of the students, responded to the query. The median (IQR 25-75) OSCE score was 13.6/20 (12.5-14.2). Students' personal factors significantly associated with a higher OSCE performance were female sex (median score of 13.7 versus 13.4; P=0.03) and good health during the clerkship (median score of 13.6 versus 12.6; P=0.02). A higher OSCE performance was associated with an increased number (≥6)  of medicine clerkships (median score of 13.8 versus 13.3; P=0.02) and a decreased number (<3) of surgery clerkships (median score of 13.7 versus 12.9; P=0.009). There was no correlation between the OSCE score and medical school performance (Spearman's correlation, r=0.24). CONCLUSION: Homogenization of student's clerkships, assistance to students with health problems seem to be teaching approaches to promote success at OSCEs.

Hydrogen peroxide vapour is an effective replacement for Formaldehyde in a BSL4 Foot and mouth disease vaccine manufacturing facility.

An evaluation of the efficacy of 35% hydrogen peroxide vapour (HPV) against two strains of FMDV was conducted over a period of 6 months. FMDV biological indicators were produced on-site using strains obtained from a commercial FMDV vaccine manufacturing process. FMDV biological indicators were distributed within a BSL4 laboratory and exposed to short duration hydrogen peroxide cycles. Variations in titre, support matrix (soiling), temperature and humidity were evaluated in a series of 16 exposures using over 200 individual FMDV indicators. Additional verification testing was performed in an operational material transfer lock to replicate real-world use. HPV was found to be efficacious in inactivating FMDV strains; the inoculum titre influenced the level of reduction achieved with the specified cycle. SIGNIFICANCE AND IMPACT OF THE STUDY: The classification of formaldehyde as a presumed human carcinogen has presented regulatory challenges for its continued use as a biocidal product. Institutions are actively seeking fumigants to replace formaldehyde and undertaking studies to validate biocidal efficacy, particularly in high-level biosafety facilities where the consequences of pathogen release can be extremely severe. This study builds on the already substantial scientific efficacy base of 35% hydrogen peroxide vapour and provides a comprehensive evaluation of the applicability of hydrogen peroxide vapour as a replacement for formaldehyde within a Foot & Mouth Disease (FMDV) vaccine manufacturing facility.

Modeling of elastic modulus evolution of cirrhotic human liver.

A micromechanics-based composite model is developed for the elastic behavior and its modulus evolution of cirrhotic human liver correlated with different pathological stages. Microstructurally, the cirrhotic liver is hypothesized to be pathologically elastic nodules embedded in the soft tissue matrix whose hyperelastic behavior is controlled by the Veronda-Westmann model. Under finite deformation, the total strain energy of the liver is collected through the combination of that in nodule particles and that in the tissue matrix. The overall constitutive relation of the pathological liver can further be established through the nonlinear hyperelasticity theory. Predictions of the elastic modulus and its pathological evolution are compared with available experimental data.

ImageParser: a tool for finite element generation from three-dimensional medical images.

BACKGROUND: The finite element method (FEM) is a powerful mathematical tool to simulate and visualize the mechanical deformation of tissues and organs during medical examinations or interventions. It is yet a challenge to build up an FEM mesh directly from a volumetric image partially because the regions (or structures) of interest (ROIs) may be irregular and fuzzy. METHODS: A software package, ImageParser, is developed to generate an FEM mesh from 3-D tomographic medical images. This software uses a semi-automatic method to detect ROIs from the context of image including neighboring tissues and organs, completes segmentation of different tissues, and meshes the organ into elements. RESULTS: The ImageParser is shown to build up an FEM model for simulating the mechanical responses of the breast based on 3-D CT images. The breast is compressed by two plate paddles under an overall displacement as large as 20% of the initial distance between the paddles. The strain and tangential Young's modulus distributions are specified for the biomechanical analysis of breast tissues. CONCLUSION: The ImageParser can successfully exact the geometry of ROIs from a complex medical image and generate the FEM mesh with customer-defined segmentation information.

Craniofacial measurements based on 3D-CT volume rendering: implications for clinical applications.

OBJECTIVES: This study was designed to determine the precision and accuracy of anthropometric measurements using three-dimensional computed tomography (3D-CT) volume rendering by computer systems for craniofacial clinical applications, and to compare the craniometric landmarks using bone and soft tissue protocols. METHODS: The study population consisted of 13 cadaver heads that were examined with spiral CT. The archived CT data were transferred to a workstation, and 3D-CT volume rendered images were generated using computer graphics tools. Linear measurements (n = 10), based upon conventional craniometric anatomical landmarks (n = 08), were identified in 2D-CT and in 3D-CT images by two radiologists twice each independently, and then performed by 3D-CT imaging using a computer graphics systems using bone and soft tissue protocols. In total, 520 imaging measurements were made. The soft tissues were subsequently removed from the cadaver heads and the measurements were repeated using an electromagnetic 3 Space trade mark digitizer. RESULTS: The results demonstrated no statistically significant difference between interobserver and intraobserver measurements or between imaging and physical measurements in both 3D-CT protocols. The standard error was found to be between 0.45% and 1.44% for all the measurements in both protocols, indicating a high level of precision. Furthermore, there was no statistically significant difference between imaging and physical measurements (P > 0.01). The error between the mean actual and mean 3D-based linear measurements was 0.83% for bone and 1.78% for soft tissue measurements, demonstrating high accuracy of both 3D-CT protocols. CONCLUSIONS: 3D-CT volume rendering images using craniometric measurements can be used for anthropological studies involving craniofacial applications.

Craniofacial computed tomography scanning: technology, applications and future trends.

OBJECTIVES: Craniofacial imaging in three dimensions depends on computed tomography (CT) and related technologies. This paper explains the state-of-the-art for medical and dedicated craniofacial cone-beam CT scanners. METHOD: Current medical CT scanners are surveyed, especially the recently announced 16 simultaneous slice models with subsecond source-detector rotation times and spiral/helical third generation geometry. The medical scanner technology is contrasted with dedicated low-cost craniofacial cone-beam CT scanners to delineate the relevant technologies and clarify the differences. RESULTS: CT scanners performance in any task is determined by their detectors and reconstruction algorithm primarily and to a lesser extent by the X-ray source, dose utilization, computational and display electronics, and software for post-processing. Each of these components differs between medical and low-cost cone-beam scanners, and the differences are tabulated and explained. CONCLUSION: Low-cost craniofacial CT scanners are significantly different from general purpose medical CT scanners, with compromises in technical performance. Despite their limitations, these instruments are remarkably useful for their intended application domain and should improve as computers continue to increase their performance.

Craniofacial imaging informatics and technology development.

PURPOSE: 'Craniofacial imaging informatics' refers to image and related scientific data from the dentomaxillofacial complex, and application of 'informatics techniques' (derived from disciplines such as applied mathematics, computer science and statistics) to understand and organize the information associated with the data. METHOD: Major trends in information technology determine the progress made in craniofacial imaging and informatics. These trends include industry consolidation, disruptive technologies, Moore's law, electronic atlases and on-line databases. Each of these trends is explained and documented, relative to their influence on craniofacial imaging. RESULTS: Craniofacial imaging is influenced by major trends that affect all medical imaging and related informatics applications. The introduction of cone beam craniofacial computed tomography scanners is an example of a disruptive technology entering the field. An important opportunity lies in the integration of biologic knowledge repositories with craniofacial images. CONCLUSION: The progress of craniofacial imaging will continue subject to limitations imposed by the underlying technologies, especially imaging informatics. Disruptive technologies will play a major role in the evolution of this field.

Analytic modeling of breast elastography.

The elastic moduli of tumors change during their pathological evolution. Elastographic imaging has potential for detecting and characterizing cancers by mapping the stiffness distribution in tissues. In this paper a micromechanics-based analytical method was developed to detect the location, size, and elastic modulus of a tumor mass embedded in a symmetric two-dimensional breast tissue. A closed-form solution for the strain elastograms (forward problem) was derived. A computational algorithm for the inverse problem was developed for the detection, localization, and characterization of a heterogeneous mass embedded in a breast tissue. Numerical examples were presented to evaluate the proposed method's performance. The detectability of a tumor mass was estimated with respect to lesion location, size, and modulus contrast ratio. It was shown that the micromechanics theory provides a powerful tool for the diagnosis of breast cancer.

A study on the section sensitivity profile in multi-row-detector spiral CT.

The section sensitivity profile (SSP) was well understood in the case of single-row-detector spiral CT. With the introduction of multi-row-detector spiral CT and the transition into cone-beam spiral CT, a revisit to the SSP issue becomes necessary. In this paper, the SSP of multi-row-detector spiral CT is formulated for the half-scan interpolation method at any transverse position. Based on the SSP formula, numerical simulation is performed to quantify the characteristics of the SSP with the number of detector rows up to 40. It is shown that the SSP varies as a function of the pitch and the number of detector rows. Given an appropriate selection of the pitch and the number of detector rows, the SSP does not change very much over the field of view in terms of the mean, the slice thickness, and the skewness of the SSP. Although in general applications the SSP at the gantry iso-center can be used as the representative of the SSP family, for more accurate analyses the spatial variation of the SSP must be taken into account.

3D volume rendering using multislice CT for dental implants.

OBJECTIVES: To determine the precision and accuracy of three-dimensional (3D) volume rendering spiral multislice computed tomography (CT)-based linear measurements of the mental foramen for dental implants, in vitro, and their precision, in vivo. METHODS: Five cadaver heads were imaged by multislice spiral CT (Toshiba Aquilion) with 0.5 mm thick axial slices (0.5 mm/0.5 s of table feed) at 0.5 mm interval reconstructions. The image data sets were transferred to a networked computer workstation. Using computer graphics the data were analysed with a 3D volume rendering technique using Vitrea software. Two oral and maxillofacial radiologists, independently, made electronic linear measurements from the superior border of the mental foramen to the crest of the alveolar process. The soft tissues were removed and physical measurements made using a 3 Space (Polhemus, Colchester, VT, USA) electromagnetic digitizer with a personal computer running Windows 98. The same linear measurements of 15 patients using the same imaging methodology were performed and the precision was analysed. RESULTS: The findings showed no statistically significant inter- or intra-observer differences in vitro and in vivo, or between imaging and physical measurements in vitro (P>0.05). CONCLUSIONS: 3D multislice spiral CT imaging allows highly accurate measurements for dental implant placement in proximity to the mental foramen. Computer graphics software, using volume rendering is suitable for implant planning.

The craniofacial anomalies archive at St. Louis Children's Hospital: 20 years of craniofacial imaging experience.

This article describes how the Craniofacial Imaging Laboratory at the Cleft Palate and Craniofacial Deformities Institute, St. Louis Children's Hospital, Washington University Medical Center, has developed an electronic archive for the storage of computed tomography image digital data that is independent of scanner hardware and independent of units of storage media (i.e., floppy disks and optical disks). The archive represents one of the largest repositories of high-quality computed tomography data of children with craniofacial deformities in the world. Archiving reconstructed image data is essential for comparative imaging, surgical simulation, quantitative analysis, and use with solid model fabrication (e.g., stereolithography). One tertiary craniofacial center's experience in the establishment and maintenance of such an archive through three generations of storage technology is reported. The current archive is housed on an external 35-GB hard drive attached to a Windows-based desktop server. Data in the archive were categorized by specific demographics into groups of patients, number of scans, and diagnoses. The Craniofacial Imaging Laboratory archive currently contains computed tomography image digital data for 1827 individual scans. The earliest scan was done in 1980; the most recently stored scan for the purposes of this report occurred in May of 2000. The average number of scans archived per complete year was 94, with a range of 59 to 138. Of the 1827 total scans, 74 percent could be classified into specific diagnostic categories. The majority of the archive (55 percent) is composed of the following five diagnoses: sagittal synostosis (17 percent), unilateral coronal synostosis (11 percent), hemifacial microsomia (10 percent), plagiocephaly without synostosis (10 percent), and metopic synostosis (7 percent). Storage of computed tomography image data in a digital archive currently allows for continuous upgrading of image display and analysis and facilitates longitudinal and cross-sectional studies, both intramural and extramural. Internet access for clinical and research purposes is feasible, but contingent on protection of patient confidentiality. The future of digital imaging regarding craniofacial computed tomography scan storage and processing is also discussed.

3D-CT vascular setting protocol using computer graphics for the evaluation of maxillofacial lesions.

In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT) reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.

Evaluation of an ossifying fibroma using three-dimensional computed tomography.

We describe the appearance of a mandibular ossifying fibroma in spiral computed tomography-based multiplanar (MPR) and three-dimensional (3D) reconstruction using computer graphics. The usefulness of the interactive reconstructed images, especially using a vascular protocol, for qualitative and quantitative analyses is demonstrated. This technique is an important adjunct to evaluation with conventional axial CT.

Solubilization of rhamnogalacturonan I galactosyltransfrases from membranes of a flax cell suspension.

Galactosyltransferases (GalTs), capable of transferring a galactosyl residue from UDP-galactose (UDP-Gal) to polysaccharide acceptor, were solubilized from flax (Linum usitatissimum L.) membranes using 0.5% CHAPS. The observed requirement for a rhamnogalacturonan I (RG-I) exogenous substrate to stimulate the solubilized GalT activity provided the first evidence for the presence of RG-I GalT activities in flax cells. An assay to measure specifically the products of this RG-I GalT activity was designed, based on size-exclusion chromatography. Labelled products were characterized as an RG-I polymer by using purified RG-I hydrolase or lyase. At pH 8 and in the presence of 5 mM CaCl2, beta-D-galactosyl residues were specifically transferred onto RG-I branches of short beta-(1 --> 4)-D-galactan side chains. These side chains were liable to hydrolysis by beta-galactosidase and endo-beta-(1 --> 4)-D-galactanase. The RG-I GalT had a temperature optimum of 30 degrees C. an apparent Km for UDP-Gal and exogenous RG-I substrate of 460 +/- 40 microM and 1.1 +/- 0.1 mg ml(-1) respectively, and a Vmax of 3.0 +/- 0.5 pkat mg(-1) protein.

Image-based dose planning of intracavitary brachytherapy: registration of serial-imaging studies using deformable anatomic templates.

PURPOSE: To demonstrate that high-dimensional voxel-to-voxel transformations, derived from continuum mechanics models of the underlying pelvic tissues, can be used to register computed tomography (CT) serial examinations into a single anatomic frame of reference for cumulative dose calculations. METHODS AND MATERIALS: Three patients with locally advanced cervix cancer were treated with CT-compatible intracavitary (ICT) applicators. Each patient underwent five volumetric CT examinations: before initiating treatment, and immediately before and after the first and second ICT insertions, respectively. Each serial examination was rigidly registered to the patient's first ICT examination by aligning the bony anatomy. Detailed nonrigid alignment for organs (or targets) of interest was subsequently achieved by deforming the CT exams as a viscous-fluid, described by the Navier-Stokes equation, until the coincidence with the corresponding targets on CT image was maximized. In cases where ICT insertion induced very large and topologically complex rearrangements of pelvic organs, e.g., extreme uterine canal reorientation following tandem insertion, a viscous-fluid-landmark transformation was used to produce an initial registration. RESULTS: For all three patients, reasonable registrations for organs (or targets) of interest were achieved. Fluid-landmark initialization was required in 4 of the 11 registrations. Relative to the best rigid bony landmark alignment, the viscous-fluid registration resulted in average soft-tissue displacements from 2.8 to 28.1 mm, and improved organ coincidence from the range of 5.2% to 72.2% to the range of 90.6% to 100%. Compared to the viscous-fluid transformation, global registration of bony anatomy mismatched 5% or more of the contoured organ volumes by 15-25 mm. CONCLUSION: Pelvic soft-tissue structures undergo large deformations and displacements during the external-beam and multiple-ICT course of radiation therapy for locally advanced cervix cancer. These changes cannot be modeled by the conventional rigid landmark transformation method. In the current study, we found that the deformable anatomic template registration method, based on continuum-mechanics models of deformation, successfully described these large anatomic shape changes before and after ICT. These promising modeling results indicate that realistic registration of the cumulative dose distribution to the organs (or targets) of interest for radiation therapy of cervical cancers is achievable.