Exploring the cognitive assessment potential of MRI-based volumetric hippocampal segmentation in Parkinson's disease.

PURPOSE: To investigate the potential of magnetic resonance imaging (MRI)-based total and segmental hippocampus volume analysis in the assessment of cognitive status in Parkinson's disease (PD). METHODS: We divided participants into three groups Group A-Parkinson patients (Pp) with normal cognitive status (n = 25), Group B-Pp with dementia (n = 17), and Group C-healthy controls (n = 37). Three-dimensional T1W Fast Spoiled Gradient Recalled Echo images were used for Volbrain hippocampus subfield segmentation. We used the "Winterburn" protocol, which divides the hippocampus into five segments, Cornu Ammonis (CA),CA2/CA3, CA4/dentate gyrus, stratum radiatum, lacunosum, and moleculare, and subiculum. RESULTS: A total of 79 participants were included in the study, consisting of 42 individuals with PD (64.2% male) and 37 healthy controls (54.1% male). The mean age of PD was 60.9 ± 10.7 years and the mean age of control group was 59.27 ± 12.3 years. Significant differences were found in total hippocampal volumes between Group A and B (p = .047. Statistically significant group differences were found in total, right, and left CA1 volumes (analysis of variance [ANOVA]: F(2,76) = 8.098, p = .001; F(2,76) = 7.628, p = .001; F(2,76) = 5.084, p = .008, respectively), as well as in total subiculum volumes (ANOVA: F(2,76) = 4.368, p = .016). Post hoc tests showed that total subiculum volume was significantly lower in individuals with normal cognitive status (0.474 ± 0.116 cm3) compared to healthy controls (0.578 ± 0.151 cm3, p = .013). CONCLUSION: Volumetric hippocampal MRI can be used to assess the cognitive status of Pp. Longitudinal studies that evaluate Pp who progress from normal cognition to dementia are required to establish a causal relationship.

Investigation of Childhood Pneumonia With Thoracic Ultrasound: A Comparison Between X-ray and Ultrasound.

ABSTRACT: Childhood pneumonia is a common entity, and chest x-rays are widely used as an initial diagnostic step. To avoid radiation exposure in the pediatric age group, we assessed whether the diagnostic accuracy of ultrasound (US) imaging is sufficient in the diagnosis. One hundred thirty-three children with pneumonia (72 girls/61 boys) were participated to study between 2019 and 2021. All participants had a chest x-ray. Radiologists who perform the US scans and interpret the x-rays were blinded to each other. A comparative analysis was also done to assess US findings on pneumonia for different age groups. We compare the diagnostic accuracy of US and x-rays by McNemar test and receiver operating characteristic curves. Intraclass correlation coefficient values were calculated for the assessment of interobserver agreement of x-ray evaluation. The participants' ages ranged from 1 month to 17 years and 8 months with a median age of 24 months (Q 1 : 8 and Q 3 : 66 months). Hospital stay lengths were longer, consolidation depths were greater, and presence of air bronchogram or pleural effusion was more frequent in school-age children. The proportion of consolidation seen on chest x-ray and transthoracic US scan was significantly different ( P < 0.001). The area under the curve was greater in the US than in the chest x-ray (area under the curve, 0.94 and 0.76 respectively). There was a good agreement between the 2 interpreters on chest x-ray assessment ( κ = 0.661). The thoracic US can be used as a safe and efficient imaging tool in the diagnosis of pediatric pneumonia.

Plasminogen activator inhibitor-1 levels as an indicator of severity and mortality for COVID-19.

OBJECTIVE: Coronavirus disease-19 (COVID-19) is a multisystemic disease that can cause severe illness and mortality by exacerbating symptoms such as thrombosis, fibrinolysis, and inflammation. Plasminogen activator inhibitor-1 (PAI-1) plays an important role in regulating fibrinolysis and may cause thrombotic events to develop. The goal of this study is to examine the relationship between PAI-1 levels and disease severity and mortality in relation to COVID-19. METHODS: A total of 71 hospitalized patients were diagnosed with COVID-19 using real time-polymerase chain reaction tests. Each patient underwent chest computerized tomography (CT). Data from an additional 20 volunteers without COVID-19 were included in this single-center study. Each patient's PAI-1 data were collected at admission, and the CT severity score (CT-SS) was then calculated for each patient. RESULTS: The patients were categorized into the control group (n=20), the survivor group (n=47), and the non-survivor group (n=24). In the non-survivor group, the mean age was 75.3±13.8, which is higher than in the survivor group (61.7±16.9) and in the control group (59.5±11.2), (p=0.001). When the PAI-1 levels were compared between each group, the non-survivor group showed the highest levels, followed by the survivor group and then the control group (p<0.001). Logistic regression analysis revealed that age, PAI-1, and disease severity independently predicted COVID-19 mortality rates. In this study, it was observed that PAI-1 levels with >10.2 ng/mL had 83% sensitivity and an 83% specificity rate when used to predict mortality after COVID-19. Then, patients were divided into severe (n=33) and non-severe (n=38) groups according to disease severity levels. The PAI-1 levels found were higher in the severe group (p<0.001) than in the non-severe group. In the regression analysis that followed, high sensitive troponin I and PAI-1 were found to indicate disease severity levels. The CT-SS was estimated as significantly higher in the non-survivor group compared to the survivor group (p<0.001). When comparing CT-SS between the severe group and the non-severe group, this was significantly higher in the severe group (p<0.001). In addition, a strong statistically significant positive correlation was found between CT-SS and PAI-1 levels (r: 0.838, p<0.001). CONCLUSION: Anticipating poor clinical outcomes in relation to COVID-19 is crucial. This study showed that PAI-1 levels could independently predict disease severity and mortality rates for patients with COVID-19.

Prognostic significance of HDL-C on long-term mortality in patients with COVID-19 pneumonia in the Turkish population: A potential mechanism for population differences.

Coronavirus disease 2019 (COVID-19) is diagnosed by the evidence of the presence of multiple phenotypes, including thrombosis, inflammation, and alveolar and myocardial damage, which can cause severe illness and mortality. High-density lipoprotein cholesterol (HDL-C) has pleiotropic properties, including anti-inflammatory, anti-infectious, antithrombotic, and endothelial cell protective effects. The aim of this study was to investigate the HDL-C levels and one-year mortality after the first wave of patients with COVID-19 were hospitalized. Data from 101 patients with COVID-19 were collected for this single-center retrospective study. Lipid parameters were collected on the admission. The relationship between lipid parameters and long-term mortality was investigated. The mean age of the non-survivor group (n = 38) was 68.8 ± 14.1 years, and 55% were male. The HDL-C levels were significantly lower in the non-survivors group compared with the survivors (26.9 ± 9.5 vs 36.8 ± 12.8 mg/dl, respectively p < 0.001). Multivariate regression analysis determined that age, C-reactive protein, D-dimer, hypertension, and HDL-C as independent predictors for the development of COVID-19 mortality. HDL-C levels <30.5 mg/dl had 71% sensitivity and 68% specificity to predict one-year mortality after COVID-19. The findings of this study showed that HDL-C is a predictor of one-year mortality in Turkish patients with COVID-19. COVID-19 is associated with decreased lipid levels, and it is an indicator of the inflammatory burden and increased mortality rate. The consequences of long-term metabolic dysregulations in patients that have recovered from COVID-19 still need to be understood.

Discrepancy between biomarkers of lung injury and 1-year mortality in COVID-19.

BACKGROUND: COVID-19 global pandemic started in late 2019 with the first wave. In this cross-sectional and observational study, we evaluated the associations between the biomarkers, COVID-19 pneumonia severity and 1-year mortality. METHODS: A sample of 276 polymerase chain reaction (PCR)-positive patients for SARS-CoV-2 was included. Computerized tomography severity score (CT-SS) was used to assess the severity of COVID-19 pneumonia in 222 cases. Multivariate analyses were performed to find the predictors of CT-SS, severe CT-SS (≥20) and 1-year mortality. Biomarkers of ferritin, high-sensitive C-reactive protein (CRP), lactate dehydrogenase (LDH), cardiac troponin (cTn), neutrophil-to-lymphocyte ratio (NLR), uric acid (UA) and d-dimer were routinely measured. RESULTS: Severe CT-SS (>20) was observed in 86 (31.2%) cases. Mortality was observed in 75 (27.2%) patients at 1 year. LDH displayed the highest predictive accuracy for severe CT-SS (AUC 0.741, sensitivity = 81% and specificity = 68%, cut-off value: 360 mg/dl). Linear regression analysis displayed that LDH predicted CT-SS [B = 11 (95% CI for B = 5-17, p < .001)]. Age was the most significant parameter that was associated with severe CT-SS (OR 0.96, 95% CI 0.92-0.99, p = .015). d-dimer was the only biomarker that predicted with 1-year mortality (OR 1.62, 95% CI 1.08-2.42, p = .020). CONCLUSION: LDH is a sensitive and specific biomarker to determine patients with severe lung injury in COVID-19. d-dimer is the only biomarker that predicts 1-year mortality. Neither LDH nor CT-SS is associated with 1-year mortality.

Evaluation of the Association between Lumbar Spinal Stenosis and Lumbar Subcutaneous Fat Tissue Thickness by MRI: A Novel Perspective.

OBJECTIVE: To evaluate whether lumbar subcutaneous fat tissue thickness (LSFTT) on midsagittal magnetic resonance imaging (MRI) is associated with lumbar spinal stenosis (LSS). STUDY DESIGN: Observational cross-sectional study. PLACE AND DURATION OF STUDY: Department of Radiology and Neurosurgery, Istanbul Medeniyet University School of Medicine, Istanbul, Turkey between January 2018 and December 2020. METHODOLOGY: The study group included 79 patients, who had undergone surgery for lumbar spinal stenosis. The control group included MRI scans of 80 individuals without lumbar spinal stenosis. Association between LSFTT and LSS was analysed through a comparison of both the groups. RESULTS: The agreement between the two observers was found to be very good agreement with a two-way mixed intra-class correlation coefficient of 0.986 or higher (p <0.001). There was statistically significant differences between the LSS and non-LSS groups for both L5-S1 and L4-5 level measurements, p=0.001, and p=0.004, respectively. L5-S1 level measurements in the LSS group showed 29% increase in average with respect to the non-LSS group; and in L4-L5 level measurements, the increase was 40% in median. Females exhibited significantly higher values in both levels, (p <0.001 and p <0.001, respectively). CONCLUSIONS: Lumbar subcutaneous fat tissue thickness is significantly associated with lumbar spinal stenosis. Measuring LSFTT on mid-sagittal MRI is an easily applicable, reproducible alternative method for predicting LSS. Key Word: Lumbar, Spinal canal, Stenosis, Subcutaneous fat tissue, Magnetic resonance imaging.

Comprehensive Analysis of Factors Affecting Cochlear Size: A Systematic Review and Meta-analysis.

OBJECTIVES: To determine the cochlea's average size in humans and evaluate the relationships between certain covariates and cochlear size. METHODS: A systematic search on articles on cochlear size and published in English was conducted using Cochrane, PubMed, Web of Science, and Scopus databases up to September 15, 2020. Data were pooled using random-effects with three models. The effect of demographic, clinical, and measurement-related parameters was specifically analyzed. Meta-regression and subgroup analyses were conducted. The overall effect estimation was made for outcomes. RESULTS: The meta-analysis included 4,708 cochleae from 56 studies. The overall length of the organ of Corti was 32.94 mm (95% confidence interval [CI]: 32.51-33.38). The first and second models revealed that age, gender, country, continent, measurement method (direct, indirect), measured structure ("A" value, cochlear lateral wall), origin (in vivo, in vitro), and type (histology specimens, plastic casts, imaging) of the cochlear material did not affect the cochlear size. However, study populations (general population, patients with a cochlear implant, and patients with congenital sensorineural hearing loss [CSNHL]) were found to affect the outcomes. Compared to the other populations, patients with CSNHL had shorter cochleae. Therefore, we developed a third model and found that the general population and patients with cochlear implants did not differ in cochlear size. CONCLUSION: This meta-analysis investigated the factors that could affect the cochlear size and found that patients with CSNHL had significantly shorter cochleae, whereas other covariates had no significant effect. Laryngoscope, 132:188-197, 2022.

The Relation Between the Metopic Suture Persistence and Frontal Sinus Volume and Olfactory Fossa Depth: A Reliability Study with Semiautomatic Volume Measurement.

Objective: This study aims to investigate the relationship of the persistence of metopic suture (PMS), frontal sinus volume (FSV), and olfactory fossa depth (OFD). Methods: Tomography scans of 1,603 patients aged 18-65 years were evaluated for the presence of PMS. In the study, 74 PMS cases and 74 controls were included. The appearance of each individual's frontal sinus was classified as aplasia, hypoplasia, or normal. Two observers independently measured the lateral lamella length (LLL), OFD, and FSV. Interobserver agreement was evaluated with the intraclass correlation coefficient (ICC) and Cohen's kappa coefficient (κ). Results: The prevalence of PMS was found to be 4.99% [95% confidence interval (CI): 4.03-6.17]. The PMS group had five times higher hypoplasia/aplasia than the controls (52.70%, 95% CI: 41.48-63.66 and 10.81%, 95% CI: 5.58-19.91, respectively; p<0.001). An "almost perfect" agreement was detected among observers for the frontal sinus appearance classification: κ=0.807, p<0.001. The ICC of continuous measurements for OFD, LLL, and FSV, respectively, presented "excellent" reliability: 0.956, 0.958, and 0.981, with p<0.001 for each. LLL was shorter, OFD was shallower, and FSV was smaller in the PMS group than the control group (p<0.001). There was a moderate positive correlation between OFD, LLL, and FSV (r=0.306, r=0.302). Conclusions: This study interprets that the presence of PMS is related frontal sinus development and volume. With PMS, a smaller FS, shorter lateral lamella, and shallower olfactory fossa may be expected.

Cockayne syndrome type: a very rare association with hemorrhagic stroke.

BACKGROUND: Cockayne Syndrome (CS) is a rare autosomal recessive disorder that is mainly characterized by neurodevelopmental delay, cutaneous photosensitivity, and cachectic dwarfism. Genetic diagnosis is supported by the typical physical appearance and imaging findings of these patients. CASE: In our case, a 16-year-old female previously diagnosed as CS presented with right-sided hemiparesis. Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) images showed diffuse cerebral and cerebellar atrophies, volume loss of brain stem, calcification of the bilateral basal ganglia, hemorrhage on the posterior limb of the left internal capsule, thalamus, and posterior periventricular area. CONCLUSIONS: Cockayne syndrome is rarely associated with stroke; we report the clinical and neuroradiologic findings of CS presenting with a hemorrhagic stroke.

A newly described imaging finding for idiopathic normal pressure hydrocephalus: Can hummingbird sign contribute to the diagnosis?

Background/aim: In this study, we aimed to evaluate whether morphological changes in the mesencephalon, which were previously described as a diagnostic tool for progressive supranuclear palsy, could be associated also with idiopathic normal pressure hydrocephal Materials and methods: Consecutive 52 patients with a possible diagnosis of idiopathic normal pressure hydrocephalus (32 female, mean age 73.6 years) and 40 controls (23 female, mean age 72.7 years) with similar demographic characteristics were included the study. The morphologic changes in mesencephalon, hummingbird sign, and the vascular compression to mesencephalon were noted. Besides, three independent observers evaluated the imaging parameters for idiopathic normal pressure hydrocephalus in magnetic resonance imaging. Inter-observer reliabilities for qualitative and quantitative data were assessed using the Cronbach's alpha and intra class correlation coefficient. The correlation of the imaging parameters with each other was evaluated with Pearson correlation. Results: Hummingbird sign was found to be significantly more common among patients with idiopathic normal pressure hydrocephalus (p < 0.0001). A statistically significant correlation was found between hummingbird sign and vascular compression of patients in the study group (p < 0.0001). A substantial, good, and perfect agreement was found between observers at all levels except callosal angle (fair agreement). Conclusion: Hummingbird sign can be used to support the diagnosis of idiopathic normal pressure hydrocephalus in addition to other radiological findings. A significant correlation between vascular compression and hummingbird sign in the patient group may explain the morphological changes in the mesencephalon that resemble the Hummingbird sign, which was previously described for progressive supranuclear palsy.

Assessment of the optic nerve, optic disc, and perineural area using shear-wave elastography in patients with multiple sclerosis.

PURPOSE: To observe and describe the stiffness changes of the optic nerve in the patients with multiple sclerosis (MS) with or without optic neuritis and healthy adults via shear wave elastography (SWE). METHODS: 70 optic nerves from 35 patients with MS and 60 optic nerves from 30 healthy subjects were included prospectively in the study. The optic nerve (ON), optic disc (OD), and perineural area were evaluated with SWE and optic nerve sheat diameter (ONSD) was measured by ultrasound. RESULTS: The mean age of patients was 39.68 ± 9.99 years. There was no statistically significant difference between the groups in terms of ONSD, SWE ON, SWE OD, and SWE perineural area levels (P > .05). In the MS group; No statistically significant difference was found between patients with and without optic neuritis for the mean age, gender distribution, duration of MS, types of MS, ONSD, SWE ON, SWE OD, SWE perineural area, and Expanded Disability Status Scale (EDSS) scores (P > .05). No statistically significant difference in terms of ONSD, SWE ON, SWE OD, and SWE perineural area between the MS patients with or without optic neuritis and the control group (P > .05). CONCLUSION: Shear wave elastography measurements of the optic nerve, optic disc, and perineural area do not contribute to the evaluation of optic neuritis in a patient with MS.

Differentiation of Benign and Malignant Parotid Gland Tumors with MRI and Diffusion Weighted Imaging.

OBJECTIVE: This study investigated the effectivity of Magnetic Resonance Imaging (MRI) findings and Apparent Diffusion Coefficient (ADC) value in evaluating parotid gland tumors (PGTs), and aimed to reduce the biopsy procedure before surgery. METHODS: This retrospective study included 54 PGTs of 42 patients' (24 female, 18 male, mean age; 51.4±15.9). All of the patients had an MRI, and histopathologic diagnosis. The signal intensity [T1 and T2 Weighted (W), T1W after intravenous contrast agent injection] and mean ADC values of the PGTs were measured. Also contrast enhancement pattern (homogenous, heterogeneous, peripheral or none), margin features (well or ill-defined), sizes, location (superficial lobe/deeplobe/both), perineural spread, presence of lymphadenopathy, and extension to adjacent structures were noted. RESULTS: The distribution of PGTs was; 21 pleomorphic adenomas, 18 Warthin tumors, 2 lymph nodes, 2 mucoepidermoid carcinomas, 5 adenoid cystic carcinoma, 1 basal cell carcinoma,2 metastases and 2 lymphomas; (13 malignant and 41 benign lesions). Morphologic parameters; ill-defined margin, perineural spread, lymphadenopathy, and extension to adjacent structures were found to be significantly associated with malign lesions (p<0.01). There was a significant difference between ADC values of malignant and benign PGTs (p<0.05). Also ADC values and T2 signal intensity was significantly lower in Warthin tumors rather than pleomorphic adenomas (p<0.05). CONCLUSIONS: Mean ADC values when considered with morphological features may be accessible methods to distinguish benign and malignant PGTs, also ADC values and T2 signal intensity may be useful for differentiating pleomorphic adenomas from Warthin tumors, thereby reducing the number of biopsies and thus complications.

CT Evaluation of Variations in the Middle Cranial Fossa Foramina: A Potential Guide for Skull Base Surgery.

OBJECTIVES: To evaluate and classify the variations of foramen ovale (FO), foramen spinosum (FS). METHODS: Six hundred fifty-eight computed tomographies (CTs) were evaluated by 2 observers. Foramen ovale was classified as oval, almond, round, and slit-like. Duplication, absence, and confluence for FS were noted. Bony outgrowths were categorized as tubercule, bony plate, and spine. RESULTS: Oval shaped FO was the most common subgroup. Most common FS variation was the confluence with FO. Of bony outgrowths, tubercule-shaped were the most common type and spine-shaped ones were the least. Substantial agreement for bony plate and tubercule, almost excellent agreement for all the other parameters were found between 2 observers. CONCLUSIONS: Foramen ovale called lobulated and had not classified previously was described in this study. Computed tomography is a reliable tool for anatomical evaluation of FO and FS, which would effect the methods of middle cranial fossa surgery. Thus, radiologists should be a pathfinder about the variations of these structures.

Investigation of the accessory maxillary ostium: a congenital variation or acquired defect?

OBJECTIVE: We sought to determine whether an accessory maxillary ostium (AMO) is a congenital or acquired condition and we investigated concomitant sinus pathologies associated with this structure. METHODS: Paranasal sinus CT examinations of individuals aged ≥13 years and <13 years were compared retrospectively. In total, 552 sinuses of 276 patients aged ≥13 years (Group 1) and 284 maxillary sinuses of 142 children aged <13 years (Group 2) were evaluated. Patients were classified as AMO-positive or -negative. The following features were evaluated in Group 1: AMO presence, mucus retention cysts, mucosal thickening, sinusitis of the maxillary sinus, nasal septum deviation, concha hypertrophy, concha bullosa, primary ostium obstruction, uncinate process atelectasis, paradox concha, Agger nasi and Haller cells, and sinus hypoplasia. The sizes and locations of AMOs were also evaluated. The presence of an AMO and sinusitis were evaluated in Group 2. RESULTS: AMOs were detected in 122 sinuses in Group 1. In the AMO-positive group, sinusitis, mucosal thickening, and primary ostium obstruction were significantly more common than in the AMO-negative group (p < 0.00001). Statistically significant associations were not observed between AMO presence and other parameters. AMOs were present in two sinuses in Group 2. CONCLUSION: Our results suggest that AMOs are acquired defects caused by sinus diseases. The rare occurrence of these structures in patients aged <13 years suggests that they may be a perforation or secondary drainage pathway in patients with sinusitis or primary ostium obstruction.

Is Cochlear Length Related to Congenital Sensorineural Hearing Loss: Preliminary Data.

OBJECTIVES: This study used the data from patients with congenital sensorineural hearing loss (CSNHL) and those with normal hearing to measure and compare the length of the cochlea with high-resolution computed tomography (HRCT). MATERIALS AND METHODS: HRCT images of patients who were diagnosed with CSNHL and were candidates for cochlear implantation were evaluated retrospectively. Sixty-three ears of 33 patients were included in the study. The control group comprised 66 ears of 33 individuals. The measurements were conducted by an experienced radiologist, using three-dimensional curved multiplanar reconstruction. All the measurements were performed thrice, and the average was calculated. RESULTS: The data were distributed normally. The lengths of the cochlear components for the CSNHL and control groups were as follows: basal turn 21.66±1.01 (21.30-22.02) and 22.57±0.68 (22.32-22.81) mm, middle turn 11.58±0.69 (11.34-11.83) and 12.39±0.46 (12.23-12.56) mm, and apical turn 6.45±0.92 (6.12-6.77) and 7.12±0.65 (6.89-7.35) mm, respectively. The mean cochlear lateral wall (LW) length was significantly shorter in the CSNHL patients [39.71±1.32 (39.25-40.18) mm] than in the controls [42.09±1.17 (41.67-42.51) mm], (p<0.001). The intra-rater reliability was 0.878 (confidence interval 95%: 0.841-0.908 p<0.001). The cut-off value was 40.81 mm (sensitivity: 0.91, specificity: 0.94, and accuracy: 0.90). CONCLUSION: There were microanatomic dissimilarities between the length of the cochlea in subjects from the CSNHL group and those from the control group.

Apparent Diffusion Coefficient in Predicting the Preoperative Grade of Meningiomas.

OBJECTIVE: To investigate the relationship between the apparent diffusion coefficients (ADC) value obtained from magnetic resonance imaging (MRI) and histopathologic grade of meningiomas. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Department of Radiology, Istanbul Medeniyet University, School of Medicine, Istanbul, Turkey between January 2015 and June 2019. METHODOLOGY: Data of 45 patients with meningiomas, who underwent surgery at the University Hospital, were retrospectively reviewed; 28 patients were enrolled in the study. The pathology preparations of the patients were re-evaluated according to the World Health Organisation (WHO) 2016 classification updated by a neuropathologist. ADC values were measured in a standard region of interest range from the three consecutive sections where the mass had the largest width and from the opposite white matter. RESULTS: Fourteen patients (50%) were diagnosed with WHO grade I tumor, 11 with grade II (39.3%), and three with grade III (10.7%). The ADCmin value was found statistically significant for the differentiation of tumor grades (p = 0.018). The cut-off point of the ADCmin value was 0.634x10-3mm2s for the differential diagnosis of grade I and grade II/III meningiomas. The sensitivity of the cut-off value was found as 86% and its specificity as 57%. The patients with increased cellularity and Ki67 proliferation index had statistically significantly lower ADCmin values (p = 0.025). CONCLUSION: The data of this study show a significant difference in the ADCmin values on MRI between low- and high-grade meningiomas. A negative correlation was found between histopathologic grade and ADCmin. Key Words: Meningioma, Apparent diffusion coefficient, Magnetic resonance imaging, Histopathological grade, Quantitative.

A New Method for Determining the Level of the Carotid Artery Bifurcation.

Exact localization of the bifurcation of the common carotid artery using skin surface landmarks is important for various diagnostic and therapeutic purposes, including emergency cases. Traditional methods have confirmed their accuracy in only a certain percentage of cases and there are inconsistencies among various publications. The cervical computed tomography-angiographic examinations for any diagnostic purpose between June 2017 and December, 2017 in the authors' hospital were examined. Measurements were performed for (MT-CB) and (MT-SE) distances and the results were recorded [MT = The tip of the mastoid process; CB = common carotid artery bifurcation; SE = sternal extremity of the clavicle]. Cervical computed tomography angiography was found in the records of 91 patients in the 6-month period between June 2017 and December 2017. After exclusion criteria were applied, a total of 116 carotid bifurcation levels on the right and left sides were measured in 58 patients. The mean MT-CB distance was 6.29 ±â€Š0.9 cm (range: 2.9-8.4 cm). The mean distance between MT and SE was 15.3 ±â€Š1.7 cm (range: 9.9-19.0 cm). The (MT-CB): (MT-SE) ratios ranged from 29% to 51% with a mean of 41 ±â€Š4.2% (95% CI: 39.88%-42.10%) and a median of 41.1% (P < 0.05) (Kolmogorov-Smirnov test). The distance ratio values did not change significantly according to age and gender (respectively P = 0.341, P = 0.093). These results show that the CB is usually located at two-fifths of the distance from the mastoid tip to the sternal extremity of the clavicle and closer to the mastoid tip.

Giant arachnoid granulation mimicking dural sinus thrombosis.

Arachnoid granulations (AG) are composed of dense, collagenous connective tissue that includes clusters of arachnoid cells. They tend to invaginate into the dural sinuses, through which cerebrospinal fluid enters the venous system. AG are most commonly seen at the junction between the middle and lateral thirds of the transverse sinuses near the entry sites of the superficial veins. Presently described is the case of a 21-year-old female who presented at the clinic with recurrent headaches. Magnetic resonance (MR) imaging revealed a 3.5-cm lesion, which extended from confluens sinuum through the superior sagittal sinus. The lesion had created a scallop-shaped area of erosion in the neighboring occipital bone. To exclude sinus thrombosis, MR venography was performed, which displayed a maintained venous flow around the lesion. Headaches were treated symptomatically with medical therapy. Giant AG can be misdiagnosed as dural sinus thrombosis. MR imaging combined with MR venography is the most useful diagnostic tool to differentiate giant AG from dural sinus thrombosis.