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.

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.

Progressive hemorrhage after head trauma: predictors and consequences of the evolving injury

2002 ◽  
Vol 96 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Matthias Oertel ◽  
Daniel F. Kelly ◽  
David McArthur ◽  
W. John Boscardin ◽  
Thomas C. Glenn ◽  
...  
Keyword(s):  
Risk Factors ◽  
Ct Scan ◽  
Ct Scanning ◽  
Older Age ◽  
Ct Scans ◽  
Female Ratio ◽  
Content Type ◽  
Male Sex ◽  
Time From Injury ◽  
Fine Print

Object. Progressive intracranial hemorrhage after head injury is often observed on serial computerized tomography (CT) scans but its significance is uncertain. In this study, patients in whom two CT scans were obtained within 24 hours of injury were analyzed to determine the incidence, risk factors, and clinical significance of progressive hemorrhagic injury (PHI). Methods. The diagnosis of PHI was determined by comparing the first and second CT scans and was categorized as epidural hematoma (EDH), subdural hematoma (SDH), intraparenchymal contusion or hematoma (IPCH), or subarachnoid hemorrhage (SAH). Potential risk factors, the daily mean intracranial pressure (ICP), and cerebral perfusion pressure were analyzed. In a cohort of 142 patients (mean age 34 ± 14 years; median Glasgow Coma Scale score of 8, range 3–15; male/female ratio 4.3:1), the mean time from injury to first CT scan was 2 ± 1.6 hours and between first and second CT scans was 6.9 ± 3.6 hours. A PHI was found in 42.3% of patients overall and in 48.6% of patients who underwent scanning within 2 hours of injury. Of the 60 patients with PHI, 87% underwent their first CT scan within 2 hours of injury and in only one with PHI was the first CT scan obtained more than 6 hours postinjury. The likelihood of PHI for a given lesion was 51% for IPCH, 22% for EDH, 17% for SAH, and 11% for SDH. Of the 46 patients who underwent craniotomy for hematoma evacuation, 24% did so after the second CT scan because of findings of PHI. Logistic regression was used to identify male sex (p = 0.01), older age (p = 0.01), time from injury to first CT scan (p = 0.02), and initial partial thromboplastin time (PTT) (p = 0.02) as the best predictors of PHI. The percentage of patients with mean daily ICP greater than 20 mm Hg was higher in those with PHI compared with those without PHI. The 6-month postinjury outcome was similar in the two patient groups. Conclusions. Early progressive hemorrhage occurs in almost 50% of head-injured patients who undergo CT scanning within 2 hours of injury, it occurs most frequently in cerebral contusions, and it is associated with ICP elevations. Male sex, older age, time from injury to first CT scan, and PTT appear to be key determinants of PHI. Early repeated CT scanning is indicated in patients with nonsurgically treated hemorrhage revealed on the first CT scan.

Traumatically Induced Brain Stem Hemorrhage and the Computerized Tomographic Scan

Neurosurgery ◽  
1979 ◽  
Vol 4 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Paul R. Cooper ◽  
Kenneth Maravilla ◽  
Joel Kirkpatrick ◽  
Sarah F. Moody ◽  
Frederick H. Sklar ◽  
...  
Keyword(s):  
Ct Scan ◽  
Brain Stem ◽  
Thin Section ◽  
Ex Vivo ◽  
Ct Scanning ◽  
Volume Effect ◽  
Brain Parenchyma ◽  
Ct Scanner ◽  
Cross Sectional ◽  
The Brain

Abstract The computerized tomographic (CT) scan has revolutionized the management of cerebral trauma. Nevertheless, visualization of traumatically induced lesions of the brain stem by the CT scanner remains difficult. Seven patients with autopsy or CT evidence of brain stem hemorrhage were identified over a 1-year period. In six of these patients, brain stem hemorrhage could be defined by CT scan. As part of a prospective study of CT changes after head injury, we performed serial CT scans on six of the seven patients. Clinical experience shows that timing is important for identification of these lesions and that inability to visualize brain stem hematomas may occur because of the development of hematomas after CT scanning, evolution of hemorrhagic lesions that makes them isodense with the surrounding brain stem, patient movement, and technical factors such as the partial volume effect. Experimental injection of fresh blood into the pons and midbrain of cadavers shows that lesions as small as 0.1 ml in volume may be visualized by ex vivo thin section CT scanning techniques. However, the character and anatomical configuration of the hemorrhage may be as important in determining CT visualization as is the volume of the hemorrhage. For example, a hematoma displacing the brain parenchyma was visualized, but a similar-sized small hemorrhage that had diffused through the brain stem tissues was not. Although many of the experimentally placed lesions extended over a rostral-caudal length of 15 mm or more in the brain stem, no lesion was seen on more than three thin section scans. This is explained by the presence of lesions that, although extensive in a rostral-caudal direction, had relatively small cross sectional areas available for identification by the CT scanner. The small size of traumatic lesions of the brain stem and their proximity to bony structures at the base of the skull are not insurmountable obstacles to visualization of brain stem hemorrhages. Serial scanning and the application of thin section computed tomography will lead to identification of most of these lesions.

A population-based study of the effect of FDG PET/CT in the management of liver-limited colorectal adenocarcinoma (CRC) metastases.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 3610-3610
Author(s):  
Maria Yi Ho ◽  
Tarnjit Parhar ◽  
Don Wilson ◽  
Winson Y. Cheung ◽  
Howard John Lim
Keyword(s):  
British Columbia ◽  
Ct Scan ◽  
Metastatic Disease ◽  
De Novo ◽  
Ct Scanning ◽  
Primary Objective ◽  
Ct Scans ◽  
Extrahepatic Disease ◽  
Liver Lesions ◽  
Pet Ct

3610 Background: PET/CT scans are publically funded in British Columbia for staging in liver limited metastatic CRC. However, past studies have been equivocal about the utility of PET/CT as some report as high as a 20-30% change in management while others report <10% change in management. Our primary objective was to assess the effect of the addition of PET/CT to CT scanning for the management of liver limited colorectal cancer. Methods: Patients who underwent PET/CT scan for de novo liver limited metastatic disease from 2005-2011 in the province of British Columbia were identified using the PET/CT database. Patients recently completed or currently on chemotherapy were excluded. We determined the concordance rates between CT and PET/CT scans with respect to the extra-hepatic disease, the number of lesions in the liver and the location of liver lesions. Results: 349 patients were identified. The most common indications for PET/CT scans after an initial CT scan were: detection of extrahepatic disease (77%), confirmation of the malignant nature of the liver lesions (8%) and the extent of extrahepatic disease (15%). PET/CT and CT were discordant in 39% of cases for the extent of metastatic disease. PET/CT revealed extrahepatic disease in 27% of the cases for which CT only detected liver limited disease. In contrast, 13% of patients were downstaged when CT liver lesions were demonstrated not to be FDG avid. Concordance of PET/CT and CT scans on the number and location of liver lesions was 52% and 85%, respectively. PET/CT revealed additional number of liver lesions and multilobar disease in 26% and 12% of cases, respectively. Furthermore, the median time between PET/CT and CT were 64.3 days and 64.1 days for concordant and discordant cases (p=0.88). Conclusions: PET/CT scans provided additional information compared to CT scans which could have implications for surgical management. Our study supports the utility and public funding of PET/CT in addition to CT in patients with potentially surgically curable metastatic CRC involving the liver.

Reliability of CT scan cerebral hemispheric asymmetry measurements across multiple CT scans and variability in CT scanning angulation.

1989 ◽  
Vol 3 (4) ◽  
pp. 231-241
Author(s):  
Carole L. Palumbo ◽  
Margaret A. Naeser ◽  
Alison D. York
Keyword(s):  
Ct Scan ◽  
Hemispheric Asymmetry ◽  
Ct Scanning ◽  
Ct Scans

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.

Radiographic and CT Evaluation of Tibiofibular Syndesmotic Diastasis: A Cadaver Study

1997 ◽  
Vol 18 (11) ◽  
pp. 693-698 ◽  
Author(s):  
Nabil A. Ebraheim ◽  
Jike Lu ◽  
Hua Yang ◽  
Anis O. Mekhail ◽  
Richard A. Yeasting
Keyword(s):  
Ct Scan ◽  
Ct Scanning ◽  
Cadaver Study ◽  
Lower Limbs ◽  
Ankle Injuries ◽  
Ct Scans ◽  
Tibiofibular Syndesmosis ◽  
Postoperative Evaluation ◽  
Plain Radiographs ◽  
Ct Evaluation

Twelve cadaver lower limbs were used for radiographic and CT assessment of the tibiofibular syndesmosis. Plastic spacers were placed in the distal tibiofibular intervals of each specimen in successive 1-mm increments until diastasis could be appreciated on the plain radiographs. All 2- and 3-mm diastases could be noted and clearly identified on CT scans, while the 1-, 2-mm, and half of the 3-mm syndesmotic diastases could not be appreciated with routine radiographs. CT scanning is more sensitive than radiography for detecting the minor degrees of syndesmotic injuries. Therefore, a CT scan can be performed in cases of syndesmotic instability after ankle injuries and for preoperative or postoperative evaluation of the integrity of the distal tibiofibular syndesmosis in cases of doubtful condition of the syndesmosis.

Abnormal computed tomography brain scans in children with acute lymphoblastic leukemia: serial long-term follow-up.

1985 ◽  
Vol 3 (1) ◽  
pp. 12-18 ◽  
Author(s):  
R Riccardi ◽  
P Brouwers ◽  
G Di Chiro ◽  
D G Poplack
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Ct Scan ◽  
Lymphoblastic Leukemia ◽  
Ct Scanning ◽  
Preventive Therapy ◽  
Ct Scans ◽  
Asymptomatic Children ◽  
Long Term Follow Up

In a previous study we reported the occurrence of computed tomographic (CT) brain-scan abnormalities in a group of asymptomatic children with acute lymphoblastic leukemia (ALL) who had received prophylactic cranial irradiation and maintenance intrathecal chemotherapy. One or more of four types of CT-scan abnormalities were observed: ventricular dilatation (VD), subarachnoid space dilatation (SAD), areas of parenchymal decreased attenuation coefficient (DAC), and intracerebral calcifications (CALs). To study the natural history of these findings, serial CT scans were obtained on 24 of the original 32 patients who were available for long-term follow-up. CT scanning was performed for a minimum of seven years from the initiation of CNS preventive therapy. Review of the CT scans showed that VD (n = 5) and SAD (n = 7) were stable over the time of follow-up. DAC, originally observed in two patients, was no longer present on follow-up scans. In contrast, five patients developed CALS from five to seven years after initiation of CNS preventive therapy. All occurred in children who were less than 8 years of age at the time of diagnosis (P less than .01). These data indicate that CALs may develop many years after the cessation of CNS preventive therapy and suggest that long-term CT-scan follow-up should be considered in children who have received CNS preventive therapy.

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.

The Fissural Complex of the Lung: Anatomy and Variations on Thin-Section CT Scans

1994 ◽  
Vol 30 (3) ◽  
pp. 481
Author(s):  
Kyung Soo Lee ◽  
Byoung Ho Lee ◽  
Il Young Kim ◽  
Pyo Nyun Kim ◽  
Won Kyung Bae
Keyword(s):  
Thin Section ◽  
Ct Scans ◽  
Lung Anatomy
Sign in / Sign up

Export Citation Format

Share Document