Explore the vast range of titles available.

A study and spatiotemporal radiological characterization of water for human use and consumption in the main rural populations of the center of the State of Veracruz was carried out, covering 22 municipalities. The objective was to estimate the annual effective dose as a function of the concentration of gross alpha and beta activity. For this purpose, a low background proportional flux detection system calibrated with NIST-traceable radioactive standards was used. Sampling included only wells, springs, and lagoons in rural areas that supply water to these populations. The decision was based on the fact that these do not have a physicochemical treatment and was carried out during the dry and rainy seasons, which became factors of impact on the radiological material. The analysis included the results of 195 samples from 22 municipalities which showed ranges in the gross alpha of 0.052-0.95 BqL-1 with a mean of 0.376 ±0.101BqL-1 and a gross beta of 0.034-1.48 BqL-1 with a mean of 0.389 ±0.108 BqL-1. The comparison of the values obtained with respect to those of other countries and their complement with analysis of variance showed that there was a significant difference, particularly, for the results of gross alpha in the municipality of Alto Lucero de Gutierrez Barrios and gross beta in Nautla and Tecolutla in dry and rainy seasons (at a probability of p≤0.05 with the Tukey-Kramer HSD statistical test). A correlation between gross alpha and gross beta was also performed with an r of -0.18 and -0.44 in dry and rainy seasons. This means that among the radionuclides, the major sources of beta radiation are uranium and thorium decay series radionuclides. For the determination of gross alpha, the municipalities in the mountainous zones showed lower values of this activity than the municipalities in the coastal zone. Gross alpha activity values of 0.95 ± 0.11 BqL-1 were detected in the municipality of Alto Lucero de Gutiérrez Barrios in the locality of Arroyo Agrio, which exceeded the limit of the Official Mexican Standard.

The study area constitutes the Eastern flank of the Nile Delta between longitudes, 31° 39’ 9.2″–32° 20’ 9.6″ E and latitudes 31° 37′13″-31° 0′ 54″N, in the shoreline between Port-Said and Damietta. The radioelement contents were measured by gamma-spectrometry using NaI-detector and were studied mineralogically using binuclear and Environmental Scanning Electron microscopes after separation of heavy minerals by heavy liquids. eU, eTh, RaeU and K contents in the studied sediments and sabkhas are ranged from (1-2 ppm), (3-17 ppm), (1-4 ppm) and (0.45-1.25 wt.%) with averages 1.34, 7.18, 1.89 ppm and 0.77 wt.%, respectively. The average of radioelement contents is lower than the international averages, while the average of eTh/eU ratio is higher. High eTh/eU ratio reflects the poor weathering, rapid deposition of these sediments and the dominance of detrital radioactive minerals such as xenotime, monazite and zircon. eU/RaeU ratio average (0.9), is lower than unity and indicate the disequilibrium in the studied coastal sediments, suggesting disequilibrium and uranium migration out. The heavy minerals are represented meanly by magnetite, ilmenite, zircon, rutile, garnet, monazite, pyroxene and amphibole.

Nasopharynx is a complex region situated at the center of skull surrounded by various vital neurovascular structures. Surgical access to the nasopharyngeal space poses significant challenges due to the position of the internal carotid artery (ICA). Open approaches to nasopharynx utilize the lateral to medial anatomy but the endoscopic endo-nasal approach warrants knowledge about the medial to lateral anatomy. In this study we attempted to find the consistent surgical landmarks for parapharyngeal portion of internal carotid artery at the level of nasopharynx by means of cadaveric and radiological study. Eight fresh frozen cadavers (16 sides) and 30 CT angiography (60 sides) were included in the anatomical and radiological study respectively. Superior aspect of the torus tubarius was taken as the reference point in cadaveric study and C1–C2 interspace was used as the reference point for the radiological study. The distance between the ICA to the landmarks such as fossa of Rosenmullaer, torus tubarius, medial and lateral pterygoid plates were recorded. The mean distance of ICA to the fossa of Rosenmuller was 8.5 ± 1.4 mm and 9.1 ± 1.1 mm in the cadaveric and radiological study respectively. The mean distance between ICA to torus tubarius was 19.8 ± 1.3 mm in cadaveric and 20.6 ± 1.0 mm in radiological study. The mean distance of ICA to medial and lateral pterygoid plates were 25.3 ± 1.4 mm and 18.2 ± 1.4 mm in the cadaveric study and 25.9 ± 1.2 mm and 18.8 ± 1.3 mm in the radiological study respectively. On correlating the measurements between cadaveric and radiological study, the p values were not statistically significant (p > 0.05). The closest landmark to the ICA was the fossa of Rosenmuller. ICA was located at the same sagittal plane as that of the lateral pterygoid plate. The nasopharynx is a complex anatomical region closely related to ICA. Inadvertent injury to ICA is one of the dreaded complications of nasopharyngeal surgery. Fossa of Rosenmuller is only few millimeters away from the ICA and must be treated very cautiously. During the endoscopic approach, the ICA is at the sagittal plane as of the lateral pterygoid plate. This must be kept in mind when advancing toward the ICA by keeping intact the lateral pterygoid plate when possible and one should stay in the plane of medial pterygoid plate as the ICA lies posterolateral to it. Cadaveric dissections supported by radiological data would definitely aid surgeons to successfully perform surgeries in nasopharynx.

Background Cortical bone trajectory (CBT), a relatively new technique for pedicle screw insertion in the lumbar spine, is believed to have equivalent pullout and toggle characteristics compared with the traditional trajectory (TT). It has been hypothesized that the new trajectory offers higher cortical bone contact with the pedicle screws and therefore has an improved anchoring property over the traditional trajectory where the screws are inserted into the vertebral body trabecular space. The aim of this study is to evaluate the pedicle screw-cortical bone contact between the two trajectories from a radiological standpoint. Methods Two hundred twenty-two patients with degenerative lumbar spine disease underwent computed tomography scanning. For each patient, axial slices of the L4 and L5 vertebra were cut in two planes, one horizontal to the pedicle representing the plane at which pedicle screws are inserted using the TT and another in a more caudo-cranial plane representing the plane at which pedicle screws are inserted using CBT. For each trajectory, a region of interest (ROI) was selected within the area in which the screws are inserted. A CT number (Hounsfield scale) was then calculated within each ROI to compare the bone density. Results The CT numbers within the ROI for CBT were constantly almost over four times higher than that for the TT, and there was a significant difference between the values ( p  < 0.0001). Conclusions This study has demonstrated that, with the cortical bone trajectory, the pedicle screws penetrate a region that is richer in cortical bone compared to when using the traditional trajectory. This is in keeping with previous hypotheses that the new trajectory offers higher cortical bone contact.

Background The tibialis anterior tendon (TAT) presents little morphological variation. The tibialis anterior muscle originates at the lateral condyle of the tibia, the proximal one-third to two-thirds of the lateral surface of the tibia shaft, and the anterior surface of the interosseous membrane and inserts to the medial cuneiform bone and first metatarsal. The aim of our work is to classify types of TAT insertion by two complimentary methods - anatomical dissection and ultrasound examination. Methods In the first part, classical anatomical dissection was performed on 100 lower limbs (50 right, 50 left) fixed in 10% formalin solution. The morphology of the insertion of the tendon was evaluated and the muscle was subjected to the appropriate morphometric measurements. In the second part, the morphology of the TAT insertion was evaluated in 50 volunteers with ultrasound. Results The tibialis anterior muscle was present in all specimens. In the cadavers, five types of insertion were observed, the most common being Type V: a single band attaching to the medial cuneiform bone (32%). In the sonographic part, Type IV was not observed; however, an additional insertion type was recognised (Type VI), which was characterized by two identical bands attached only to the medial cuneiform bone. The most common type identified by ultrasound was Type II (35%). Conclusion The tibialis anterior tendon presents high morphological variability that can be observed both in cadavers and in vivo by ultrasound examination. Level of evidence II Prospective Comparative Study

Background Diagnosis of maxillary sinus pathology must include the clinical radiological study (CRS) and histopathological analysis. The aim of this study is 1) to describe the clinicopathological features of maxillary sinus lesions, obtained successively in a single medical centre over the last 10 years and 2) to determine the sensitivity and specificity for the diagnosis of malignant lesions based exclusively on the CRS. Methods It is a single-centre observational retrospective clinical study on patients who attended the University Hospital Complex of Santiago de Compostela (CHUS) with sinus pathologies during the period of 2009–2019. Results The sample consisted of 133 men (62.1%) and 81 women (37.9%), with an average age of 46.9 years (SD = 18.8). In terms of frequency, the most frequent pathology was the unspecified sinusitis (44.4%), followed by polyps (18.2%), malignant tumours (9.8%), inverting papilloma (7.5%), fungal sinusitis (4.7%), cysts (3.7%), benign tumours (2.3%), mucocele (2.3%) and other lesions (1.9%). Cysts and benign tumours were diagnosed earliest Vs malignant tumours (65.2 years (SD = 16.1)) were diagnosed the latest ( p  < 0.001). Based only on the CRS for malignancies, diagnostic indexes were 71.4% sensitivity and 97.9% specificity, with a Kappa value of 0.68 with ( p  < 0.001). Conclusion Maxillary sinus pathology is very varied with therapeutic and prognostic repercussions. CRS is sometimes insufficient and histopathological confirmation is essential.

Background: One of the main challenges of orthopedic surgery is adequate pain management after total knee arthroplasty. This work aimed to determine the anatomical safety area for infiltration through the posterior capsule of the knee in prosthetic surgery using Magnetic Resonance Imaging (MRI). Methods: A descriptive, observational, cross-sectional study was performed on 126 knee MRIs. The variables studied were age, sex, and distance between different neurovascular structures of the popliteal fossa (tibial nerve, common peroneal nerve, and vascular bundle). Data were analyzed for normality (Kolmogorov–Smirnov) and variance homogeneity (Levène). A value of p < 0.05 and a confidence interval of 9% were considered statistically significant for all comparisons. Student’s t-test was used to compare the means between independent samples. Results: We observed statistically significant differences between the sexes regarding EP–EPS (external plateau–external popliteal sciatic nerve (common peroneal)), EP–IPS (external plateau–internal popliteal sciatic nerve (tibial)), and IP–PA (internal plateau–popliteal artery) measurements. The average distance between both nerves, EPS–IPS (external popliteal sciatic nerve and internal popliteal sciatic nerve), was 25.96 mm in females, while the value obtained in males was 29.93 mm, but this difference was not statistically significant. Conclusions: The average distance from the posterior capsule to the EPS and IPS nerves is greater in males than in females, despite no statistical differences. The presence of a lateralized arteriovenous bundle reduces the infiltration area of the external compartment. Regarding the safety area, infiltration of the internal compartment is safe since the volume diffuses into the muscle mass of the internal gastrocnemius upon injection. To infiltrate the external compartment, the needle must move at least 2 cm from the midline toward the external side (to exceed the maximum displacement of the neurovascular bundle established at 1.82 cm), and not advance beyond 0.76 cm (minimum distance at which we located the common peroneal nerve in the external compartment).

Background Cortical bone trajectory (CBT) has been well-known in spine surgery for obtaining improved fixation while minimizing soft tissue dissection. This study was designed to compare the bone mineral density (BMD) between the CBT and traditional trajectory (TT) by using Hounsfield unit (HU) values and identify the ideal decades of patients and the suitable lumbar segments using this CBT technology from a radiological standpoint. Methods Patients were selected randomly from an institutional database based on age (evenly distributed by a decade of life) and gender. A total of 240 healthy patients had a computed tomography (CT) scan of the chest, abdomen, and pelvis. For each patient, axial slices of every vertebra were cut in two planes: one horizontal to the pedicle representing the plane wherein pedicle screws were inserted using the TT and the other in a caudocranial plane representing the plane wherein pedicle screws were inserted using the CBT. For each trajectory, a region of interest (ROI) was selected within the area wherein the screws were inserted. A CT number (HU values) was then calculated within each ROI to represent bone density. Results HU values measured at the ROI of CBT were significantly greater than those of the traditional pedicle screw in all age groups, and the specific value (ratio of the HU values of CBT/the HU values of TT) between CBT and TT was 1.92. A significant difference was observed between male and female. The HU values of CBT and TT of males were generally higher than those of females (males: CBT/TT 1.89 ± 0.45; Females: CBT/TT 1.95 ± 0.47). The specific value in HU values significantly increased with increasing age ( p = 0.000) and cauda lumbar level ( p = 0.000) in males and females. Conclusion BMD, as measured by HU values for the ROI of the CBT screw, was significantly greater than that of the traditional pedicle screw, especially in old patients and cauda lumbar segments.

The relevance of this study lies in the fact, that today the search for biocompatible materials for the management of bone defects is of importance. Such materials could become an alternative to transplants. For the replacement of bone defects, two-phasic bioactive ceramics of hydroxyapatite and β-tricalcium phosphate is a very attractive biomaterial due to its excellent biocompatibility and osteoconductivity, but the results of its use are quite controversial due to insufficient bioactivity. The purpose of this work is to investigate the osseointegration properties of two-phase bioactive ceramics doped with silicon (HTdSi), both as a single component and a component in combination with platelet-rich fibrin, as well as in comparison with the well-known imported analogue – BIO, which consists of β-tricalcium phosphate, also as an independent component and a component in combination with platelet-rich fibrin. In the experiment, the rabbits of the New Zealand white breed at the age of 3 months and with an average weight of 2.5 kg were used. The terms of implantation are 30, 60, 90 and 180 days. The advantages of the domestic bio-composite are substantiated on the basis of clinical, radiological and histological studies.In the experiment, the rabbits of the New Zealand white breed at the age of 3 months and with an average weight of 2.5 kg were used. The terms of implantation are 30, 60, 90 and 180 days.The osteointegration properties of two-phase bioactive ceramics doped with silicon (HTdSi), both as a single component and in combination with platelet fibrin, were investigated, as well as in comparison with the known imported analog - BIO, which contains β-tricalcium phosphate, both as a single component and in combination with platelet fibrin.The advantages of domestic biocomposite are substantiated on the basis of clinical, radiological and histological studies.

Percutaneous insertion of cannulated pedicle screws has been recently developed as a minimally invasive alternative to the open technique during instrumented fusion procedures. Given the reported rate of screw misplacement using open techniques (up to 40%), we considered it important to analyze possible side effects of this new technique. Placement of 60 pedicle screws in 15 consecutive patients undergoing lumbar or lumbosacral fusion, mainly for spondylolisthesis, were analyzed. Axial, coronal, and sagittal reformatted computer tomography images were examined by three observers. Individual and consensus interpretation was obtained for each screw position. Along with frank penetration, we also looked at cortical encroachment of the pedicular wall by the screw. Thirteen percent of the patients (2/15) had severe frank penetration from the screws, while 80% of them (12/15) had some perforation. On axial images the incidence of severe frank pedicle penetration was 3.3% while the overall rate of screw perforation was 23%. In coronal images the overall screw perforation rate rose to 30% while the rate of severe frank pedicle penetration remained unchanged. One patient (6.6%) suffered S1 root symptoms due to a frankly medially misplaced screw, requiring re-operation. This study has shown that percutaneous insertion of cannulated pedicle screws in the lumbar spine is an acceptable procedure. The overall rate of perforation in axial images is below the higher rates reported in the literature but does remain important. Frank penetration of the pedicle was nevertheless low. It remains a demanding technique and has to be performed with extreme care to detail.