Search results for "radiography"
showing 10 items of 720 documents
The adenoid cystic carcinoma
1988
Summary In spite of its rare incidence the adenoid cystic carcinoma must be treated with respect because of its hidden malignant character. In 5 out of 21 patients recurrences occurred much longer than5 years after he first operation. The extension of this tumour along branches of the trigeminal nerve could be well demonstrated in 7 of our patients where we were able to produce histological proof or radiographic evidence. The theory of tumour growth along the “tissue of least resistance” is illustrated by a special case report. As for the therapy, ultra-radical surgery has proved to be the most effective so far, whereas radio- or chemotherapy were only useful as palliative measures.
The relation between tumor cell proliferation and vascularization in differentiated and undifferentiated colon carcinomas in the rat.
1982
Tumor cell proliferation and tumor vascularization were investigated in differentiated and undifferentiated colon carcinomas of the rat. The following results were found: 1, in both tumor types, vascularization is developed equally well; 2, both in the differentiated and in the undifferentiated carcinomas, the number of proliferating tumor cells decreases with increasing distance from the capillaries; at a distance of about 80 microns, there is no longer any noteworthy tumor cell proliferation; 3, the differentiated and undifferentiated carcinomas differ both in the level of the mitosis index and 3H-thymidine labeling index as well as in their local proliferation pattern despite equal vascu…
Analysis of the unpredictable migration of impacted mandibular third molars: A pilot study
2020
Background Eruption of an impacted mandibular third molar (3MM) is often unpredictable. The objective of this study was to establish the radiographic parameters of migration in patients whose 3MMs evolved unpredictably. Material and Methods This was a retrospective observational study. Patients with unusual 3MM migration (away from their physiological eruption position with changes in the longitudinal and horizontal axes) and with at least two panoramic radiographs were included. To evaluate the radiographic parameters, images were superimposed, using mandibular angle and ipsilateral condyle as references. Results Of a total of 2851 patients, four were included in our study. The average age…
Sonographic evidence of intraperitoneal fluid. An experimental study and its clinical implications.
1984
In order to evaluate the sensitivity of ultrasound to intraperitoneal fluid, such as ascites or blood, an experimental study was performed in the pig. Various amounts of fluid were injected into the peritoneal cavity to investigate distribution and diagnostic criteria in different positions. As little as 10 ml of fluid was visualized around the urinary bladder in an upright position. In the supine position, 20 ml could be detected around the bladder and 30 ml around the liver. The injection of at least 60 ml resulted in a pattern of free-floating bowel loops. The sonographic findings of fluid distribution were correlated to radiological studies. As different amounts of fluid produce charact…
Multiorgan Involvement in SARS-CoV-2 Infection: The Role of the Radiologist from Head to Toe
2022
Radiology plays a crucial role for the diagnosis and management of COVID-19 patients during the different stages of the disease, allowing for early detection of manifestations and complications of COVID-19 in the different organs. Lungs are the most common organs involved by SARS-CoV-2 and chest computed tomography (CT) represents a reliable imaging-based tool in acute, subacute, and chronic settings for diagnosis, prognosis, and management of lung disease and the evaluation of acute and chronic complications. Cardiac involvement can be evaluated by using cardiac computed tomography angiography (CCTA), considered as the best choice to solve the differential diagnosis between the most common…
Territorial localization of heat shock mRNA production in sea urchin gastrulae.
1985
In situ hybridization experiments with a labeled DNA probe indicate that the ability to respond to heat shock with the production of the mRNA for the 70 kd heat shock protein is segregated into the ectodermal cells already at the gastrula stage or earlier during the embryonic development of Paracentrotus lividus.
Fast algorithm for detection of reference spheres in digital panoramic radiography.
2009
In this paper, an algorithm for detection of reference spheres from digital panoramic radiographic images is presented. The proposed algorithm was tested on a database of 107 digital panoramic radiographic images which were used for dental diagnostics. Results show that the proposed method exhibits for detection of reference spheres, a sensitivity of 97.33% and specificity of 93.85%. Performance time differed between 0.55 and 2.36s depending on image size. The aim of this work was to provide a fast ellipse detection algorithm to reduce measuring time on preoperative implant planning by lowering the computational cost.
Surgically Assisted Rapid Palatal Expansion An Acoustic Rhinometric, Morphometric and Sonographic Investigation
2001
This study aimed to evaluate the effect of surgically assisted rapid palatal expansion on the skeletal structures of the midface. Ten patients (mean age 28.5 years) were investigated by means of acoustic rhinometry, study model analysis and sonography before and after the procedure of surgically assisted rapid palatal expansion. The measurements revealed that surgically assisted rapid palatal expansion not only resulted in transverse expansion of the maxilla, providing dental arch space for lining up the teeth; the procedure also caused a substantial enlargement of the maxillary apical base and of the palatal vault, providing space for the tongue for correct swallowing and thus preventing r…
Re-exposure in cone beam CT of the dentomaxillofacial region: a retrospective study.
2018
Cone beam CT (CBCT) often uses a smaller field of view compared to conventional CT scans. This might lead to a wrong field of view with the need for secondary exposure (“retakes”). The purpose of this retrospective study was to assess the frequency of re-exposures in CBCT and to identify whether the parameters age, gender, and field of view have an influence on the re-exposure of the patient. Additionally, the causes of re-exposures were determined and categorized. METHODS: In a retrospective cohort study CBCT images of 4986 patients from the patient database from the Department of Oral Radiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany were included a…
Marginal bone loss in relation to platform switching implant insertion depth: an update
2011
A review is made, analyzing marginal bone loss in relation to the depth of implant insertion with platform switching, according to the position of the neck (supracrestal, crestal or subcrestal), and evaluating survival of the implants. A PubMed search was made of the studies in animals and humans published between 2005 and 2011, specifying platform insertion depth (supracrestal, crestal or subcrestal) and registering marginal bone loss from the time of prosthetic restoration to the end of follow-up (minimum 6 months). A total of 30 studies were included. The bone loss associated with implants placed at supracrestal level was slightly smaller than in the case of implants placed at subcrestal…