scholarly journals Quantitative assessment of the vertebral pneumaticity in an anhanguerid pterosaur using micro-CT scanning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard Buchmann ◽  
Borja Holgado ◽  
Gabriela Sobral ◽  
Leonardo dos Santos Avilla ◽  
Taissa Rodrigues
Keyword(s):  
Trabecular Bone ◽  
Quantitative Assessment ◽  
Ct Scanning ◽  
Ct Scans ◽  
Appendicular Skeleton ◽  
Micro Ct ◽  
Neural Arch ◽  
Dorsal Vertebra ◽  
Air Space

AbstractResearch on the postcranial skeletal pneumaticity in pterosaurs is common in the literature, but most studies present only qualitative assessments. When quantitative, they are done on isolated bones. Here, we estimate the Air Space Proportion (ASP) obtained from micro-CT scans of the sequence from the sixth cervical to the fourth dorsal vertebra of an anhanguerine pterosaur to understand how pneumaticity is distributed in these bones. Pneumatisation of the vertebrae varied between 68 and 72% of their total volume. The neural arch showed higher ASP in all vertebrae. Anhanguerine vertebral ASP was generally higher than in sauropod vertebrae but lower than in most extant birds. The ASP observed here is lower than that calculated for the appendicular skeleton of other anhanguerian pterosaurs, indicating the potential existence of variation between axial and appendicular pneumatisation. The results point to a pattern in the distribution of the air space, which shows an increase in the area occupied by the trabecular bone in the craniocaudal direction of the vertebral series and, in each vertebra, an increase of the thickness of the trabeculae in the zygapophyses. This indicates that the distribution of pneumatic diverticula in anhanguerine vertebrae may not be associated with stochastic patterns.

scholarly journals The quantitative assessment of interstitial lung disease with positron emission tomography scanning in systemic sclerosis patients

Rheumatology ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 1407-1415 ◽  
Author(s):  
Daphne M Peelen ◽  
Ben G J C Zwezerijnen ◽  
Esther J Nossent ◽  
Lilian J Meijboom ◽  
Otto S Hoekstra ◽  
...  
Keyword(s):  
High Resolution ◽  
Interstitial Lung Disease ◽  
Lung Disease ◽  
Fdg Pet ◽  
Quantitative Assessment ◽  
Ct Scanning ◽  
Ct Scans ◽  
Pet Ct ◽  
18F Fdg ◽  
Fdg Pet Ct

Abstract Objectives The reversibility of interstitial lung disease (ILD) in SSc is difficult to assess by current diagnostic modalities and there is clinical need for imaging techniques that allow for treatment stratification and monitoring. 18F-Fluorodeoxyglucose (FDG) PET/CT scanning may be of interest for this purpose by detection of metabolic activity in lung tissue. This study aimed to investigate the potential role of 18F-FDG PET/CT scanning for the quantitative assessment of SSc-related active ILD. Methods 18F-FDG PET/CT scans and high resolution CT scans of eight SSc patients, including five with ILD, were analysed. For comparison, reference groups were included: eight SLE patients and four primary Sjögren’s syndrome (pSS) patients, all without ILD. A total of 22 regions of interest were drawn in each patient at apical, medial and dorsobasal lung levels. 18F-FDG uptake was measured as mean standardized uptake value (SUVmean) in each region of interest. Subsequently, basal/apical (B/A) and medial/apical (M/A) ratios were calculated at patient level (B/A-p and M/A-p) and at tissue level (B/A-t and M/A-t). Results SUVmean values in dorsobasal ROIs and B/A-p ratios were increased in SSc with ILD compared with SSc without ILD (P = 0.04 and P = 0.07, respectively), SLE (P = 0.003 and P = 0.002, respectively) and pSS (P = 0.03 and P = 0.02, respectively). Increased uptake in the dorsobasal lungs and increased B/A-t ratios corresponded to both ground glass and reticulation on high resolution CT. Conclusion Semi-quantitative assessment of 18F-FDG PET/CT is able to distinguish ILD from non-affected lung tissue in SSc, suggesting that it may be used as a new biomarker for SSc-ILD disease activity.

A histological study of a femur of Plagiosuchus, a Middle Triassic temnospondyl amphibian from southern Germany, using thin sections and micro-CT scanning

2013 ◽  
Vol 92 (2-3) ◽  
pp. 97-108 ◽  
Author(s):  
D. Konietzko-Meier ◽  
A. Schmitt
Keyword(s):  
Ct Scan ◽  
Thin Section ◽  
Horizontal Plane ◽  
Middle Triassic ◽  
Ct Scanning ◽  
Ct Scans ◽  
Micro Ct ◽  
Lamellar Bone ◽  
Image Stack ◽  
Thin Sectioning

AbstractThe histology of a femur of Plagiosuchus, a Middle Triassic temnospondyl amphibian, is described on the basis of two supplementary methods: classic thin sectioning and micro-CT scanning. In addition, the effectiveness of high-resolution micro-CT scanning for histological analysis is assessed. A classic, mid-shaft thin section of the femur was prepared, but prior to slicing two micro-CT scans were made. One of these has an image stack of a total of 1,024 images in the horizontal plane and a slice thickness of 87.8 μm, so that the entire bone could be captured, while the second was at mid-shaft region only, yet with a higher resolution of 28.3 μm and an image stack of 787 images in the horizontal plane. The classic thin section shows a very small medullary region which is surrounded by a layer of endosteal bone. The thick cortex is highly porous with numerous large, mainly longitudinal, vascular canals arranged in layers. In the deepest cortex woven bone occurs and primary osteons had locally started to form (incipient fibro-lamellar bone), which gradually passes into parallel-fibred bone and more lamellar bone close to the outer surface. Remains of a Kastschenko line were identified, enabling a reconstruction of the entire growth record. Five Lines of Arrested Growth (LAG) could be counted. The micro-CT scan enabled observations of the ontogenetic growth stages and calculation of growth rate on the basis of a single specimen. The micro-CT scan permitted a reconstruction of the ontogenetic development and the exact deposition rate per annum. Moreover, at higher resolution the micro-CT scan revealed data on micro-anatomical characters, such as porosity and skeletochronology (growth mark count). In conclusion, micro-CT scans do provide an alternative in cases where thin sectioning of the original bone is not possible.

scholarly journals Maken en handelen: Merovingische kralen uit het Sittard-Kemperkoul grafveld geanalyseerd

Paleo-aktueel ◽  
2019 ◽  
pp. 65-73
Author(s):  
Hans Huisman ◽  
Marion Aarts ◽  
Mirjam Kars ◽  
Fardau Mulder ◽  
Dominique Ngan-Tillard ◽  
...  
Keyword(s):  
Ct Scanning ◽  
Glass Beads ◽  
The Other ◽  
Ct Scans ◽  
Burial Ground ◽  
Micro Ct ◽  
Chemical Analyses ◽  
Manufacturing Techniques

Making and trading: An analysis of Merovingian beads from the Sittard-Kemperkoul burial ground. Chemical analyses and micro-CT scanning were used to analyse a set of c. 725 glass beads from a single Merovingian burial (number 11) in the Sittard-Kemperkoul burial ground (Sittard-Geleen, province of Limburg). Chemical analyses of the small, opaque, yellow beads that make up the majority of the collection showed that they were, in fact, not made of glass. Rather, they were made by fusing a lead-tin-based yellow colourant with quartz. For black beads, iron was added to this mixture. The other beads were made from glass – probably of re-used Roman origin – with various colourants. The micro-CT scans provided an unrivalled image of the various manufacturing techniques that were used to make the more complex, polychrome beads.

scholarly journals Skull shape differentiation of black and white olms (Proteus anguinus anguinus and Proteus a. parkelj): an exploratory analysis with micro-CT scanning

2013 ◽  
Vol 82 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Ana Ivanović ◽  
Gregor Aljančič ◽  
Jan W. Arntzen
Keyword(s):  
Morphological Differentiation ◽  
Ct Scanning ◽  
Exploratory Analysis ◽  
Micro Ct ◽  
Black And White ◽  
Necturus Maculosus ◽  
Proteus Anguinus ◽  
Evolutionary Trajectories ◽  
Morphological Detail ◽  
Shape Changes

We performed an exploratory analysis of the morphology of the cranium in the white olm (Proteus anguinus anguinus) and the black olm (P. a. parkelj) with micro-CT scanning and geometric morphometrics. The mudpuppy (Necturus maculosus) was used as an outgroup. The black olm falls outside the white olm morphospace by a markedly wider skull, shorter vomers which are positioned further apart and by laterally positioned squamosals and quadrates relative to the palate (the shape of the buccal cavity). On account of its robust skull with more developed premaxillae a shorter otico-occipital region, the black olm is positioned closer to Necturus than are the studied specimens of the white olm. The elongated skull of the white olm, with an anteriorly positioned jaw articulation point, could be regarded as an adaptation for improved feeding success, possibly compensating for lack of vision. As yet, the alternative explanations on the evolution of troglomorphism in Proteus are an extensive convergence in white olms versus the reverse evolution towards less troglomorphic character states in the black olm. To further understand the evolutionary trajectories within Proteus we highlight the following hypotheses for future testing: i) morphological differentiation is smaller within than between genetically differentiated white olm lineages, and ii) ontogenetic shape changes are congruent with the shape changes between lineages. We anticipate that the morphological detail and analytical power that come with the techniques we here employed will assist us in this task.

scholarly journals A Microcomputed Tomographic Evaluation of Root Canal Morphology of Maxillary Second Premolars in a Pakistani Cohort

2021 ◽  
Vol 11 (11) ◽  
pp. 5086
Author(s):  
Mazen F. Alkahtany ◽  
Saqib Ali ◽  
Abdul Khabeer ◽  
Shafqat A. Shah ◽  
Khalid H. Almadi ◽  
...  
Keyword(s):  
Root Canal ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Micro Ct ◽  
Single Root ◽  
Root Canal Morphology ◽  
Spss Software ◽  
Variable Morphology ◽  
Canal Morphology

This study aimed to investigate variations in the root canal morphology of maxillary second premolar (MSP) teeth using microcomputed tomography (micro-CT). Sixty (N = 60) human extracted MSPs were collected and prepared for micro-CT scanning. The duration for scanning a single sample ranged between 30 and 40 min and a three-dimensional (3-D) image was obtained for all the MSPs. The images were evaluated by a single observer who recorded the canal morphology type, number of roots, canal orifices, apical foramina(s), apical delta(s), and accessory canals. The root canal configuration was categorized in agreement with Vertucci’s classification, and any configuration not in agreement with Vertucci’s classification was reported as an “additional canal configuration”. Descriptive statistics (such as mean percentages) were calculated using SPSS software. The most common types agreeing with Vertucci’s classification (in order of highest to lowest incidence) were types I, III, V, VII, II, and VI. The teeth also exhibited four additional configurations that were different from Vertucci’s classification: types 2-3, 1-2-3, 2-1-2-1, and 1-2-1-3. A single root was found in 96.7% and the majority of the samples demonstrated two canals (73.3%). Further, 80% of the teeth showed one canal orifice. The number of apical foramina’s in the teeth was variable, with 56.7% having solitary apical foramen. The accessory canal was found in 33.3%, and apical delta was found in only 20% of the samples. Variable morphology of the MSPs was detected in our study. The canal configuration most prevalent was type 1; however, the results also revealed some additional canal types.

scholarly journals Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

2021 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Daisy (Jihyung) Ko ◽  
Tess Kelly ◽  
Lacey Thompson ◽  
Jasmene K. Uppal ◽  
Nasim Rostampour ◽  
...  
Keyword(s):  
Onset Time ◽  
Ct Scanning ◽  
Micro Ct ◽  
Third Molars ◽  
Developmental Duration ◽  
Dental Lamina ◽  
Permanent Molars ◽  
Dental Epithelium ◽  
Space Conditions

For humans and other mammals to eat effectively, teeth must develop properly inside the jaw. Deciphering craniodental integration is central to explaining the timely formation of permanent molars, including third molars which are often impacted in humans, and to clarifying how teeth and jaws fit, function and evolve together. A factor long-posited to influence molar onset time is the jaw space available for each molar organ to form within. Here, we tested whether each successive molar initiates only after a minimum threshold of space is created via jaw growth. We used synchrotron-based micro-CT scanning to assess developing molars in situ within jaws of C57BL/6J mice aged E10 to P32, encompassing molar onset to emergence. We compared total jaw, retromolar and molar lengths, and molar onset times, between upper and lower jaws. Initiation time and developmental duration were comparable between molar upper and lower counterparts despite shorter, slower-growing retromolar space in the upper jaw, and despite size differences between upper and lower molars. Timing of molar formation appears unmoved by jaw length including space. Conditions within the dental lamina likely influence molar onset much more than surrounding jaw tissues. We theorize that molar initiation is contingent on sufficient surface area for the physical reorganization of dental epithelium and its invagination of underlying mesenchyme.

Non-Invasive Analysis of the Micro-Structural and Biomechanical Properties of Trabecular Bone in Human Femoral Head

2006 ◽  
Vol 321-323 ◽  
pp. 1070-1073
Author(s):  
Ye Yeon Won ◽  
Myong Hyun Baek ◽  
Wen Quan Cui ◽  
Kwang Kyun Kim
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Femoral Head ◽  
Trabecular Bone ◽  
Volume Fraction ◽  
Reaction Force ◽  
Bone Volume ◽  
Fe Model ◽  
Micro Ct ◽  
Trabecular Thickness

This study investigates micro-structural and mechanical properties of trabecular bone in human femoral head with and without osteoporosis using a micro-CT and a finite element model. 15 cored trabecular bone specimens with 20 of diameter were obtained from femoral heads with osteoporosis resected for total hip arthroplasty, and 5 specimens were removed from femoral head of cadavers, which has no history of musculoskeletal diseases. A high-resolution micro-CT system was used to scan each specimen to obtain histomorphometry indexes. Based on the micro-images, a FE-model was created to determine mechanical property indexes. While the non-osteoporosis group had increases the trabecular thickness, the bone volume, the bone volume fraction, the degree of anisotropy and the trabecular number compared with those of osteoporotic group, the non-osteoporotic group showed decreases in trabecular separation and structure model index. Regarding the mechanical property indexes, the reaction force and the Young's modulus were lower in the osteoporotic group than in non-osteoporotic group. Our data shows salient deteriorations in trabecular micro-structural and mechanical properties in human femoral head with osteoporosis.

Incidence of silent hemorrhage and delayed deterioration after stereotactic brain biopsy

1998 ◽  
Vol 89 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Abhaya V. Kulkarni ◽  
Abhijit Guha ◽  
Andres Lozano ◽  
Mark Bernstein
Keyword(s):  
Ct Scan ◽  
Neurological Deficit ◽  
Stereotactic Biopsy ◽  
Brain Biopsy ◽  
Ct Scanning ◽  
Ct Scans ◽  
Stereotactic Brain Biopsy ◽  
Content Type ◽  
Fine Print

Object. Many neurosurgeons routinely obtain computerized tomography (CT) scans to rule out hemorrhage in patients after stereotactic procedures. In the present prospective study, the authors investigated the rate of silent hemorrhage and delayed deterioration after stereotactic biopsy sampling and the role of postbiopsy CT scanning. Methods. A subset of patients (the last 102 of approximately 800 patients) who underwent stereotactic brain biopsies at the Toronto Hospital prospectively underwent routine postoperative CT scanning within hours of the biopsy procedure. Their medical charts and CT scans were then reviewed. A postoperative CT scan was obtained in 102 patients (aged 17–87 years) who underwent stereotactic biopsy between June 1994 and September 1996. Sixty-one patients (59.8%) exhibited hemorrhages, mostly intracerebral (54.9%), on the immediate postoperative scan. Only six of these patients were clinically suspected to have suffered a hemorrhage based on immediate postoperative neurological deficit; in the remaining 55 (53.9%) of 102 patients, the hemorrhage was clinically silent and unsuspected. Among the clinically silent intracerebral hemorrhages, 22 measured less than 5 mm, 20 between 5 and 10 mm, five between 10 and 30 mm, and four between 30 and 40 mm. Of the 55 patients with clinically silent hemorrhages, only three demonstrated a delayed neurological deficit (one case of seizure and two cases of progressive loss of consciousness) and these all occurred within the first 2 postoperative days. Of the neurologically well patients in whom no hemorrhage was demonstrated on initial postoperative CT scan, none experienced delayed deterioration. Conclusions. Clinically silent hemorrhage after stereotactic biopsy is very common. However, the authors did not find that knowledge of its existence ultimately affected individual patient management or outcome. The authors, therefore, suggest that the most important role of postoperative CT scanning is to screen for those neurologically well patients with no hemorrhage. These patients could safely be discharged on the same day they underwent biopsy.

Is Hypaque Dangerous?

PEDIATRICS ◽  
1989 ◽  
Vol 83 (4) ◽  
pp. 650-650
Author(s):  
ROBERT SCHLECHTER ◽  
ABRAHAM BESSERMAN
Keyword(s):  
Abdominal Trauma ◽  
Blunt Abdominal Trauma ◽  
Ct Scanning ◽  
Ct Scans ◽  
Solid Organ ◽  
Abdominal Ct ◽  
Injured Child ◽  
Gastric Distention ◽  
Close Observation

Concerning the use of diatrizoate sodium (Hypaque) in abdominal CT scans described by Kane et al (Pediatrics 1988;82:11-15), we agree that there is certainly much to be gained from CT scanning in blunt abdominal trauma. We question the routine use of diatrizoate sodium in an injured child predisposed to gastric distention and vomiting. This is particularly dangerous when he or she is prone and restrained and close observation at the bedside is not possible. Solid organ injuries are well demonstrated without contrast, and injury to a viscus can be evaluated clinically and by routine roentgenographic procedures.

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