Voxel level dense prediction of acute stroke territory in DWI using deep learning segmentation models and image enhancement strategies.

PURPOSE: To build a stroke territory classifier model in DWI by designing the problem as a multiclass segmentation task by defining each stroke territory as distinct segmentation targets and leveraging the guidance of voxel wise dense predictions. MATERIALS AND METHODS: Retrospective analysis of DWI images of 218 consecutive acute anterior or posterior ischemic stroke patients examined between January 2017 to April 2020 in a single center was carried out. Each stroke area was defined as distinct segmentation target with different class labels. U-Net based network was trained followed by majority voting of the voxel wise predictions of the model to transform them into patient level stroke territory classes. Effects of bias field correction and registration to a common space were explored. RESULTS: Of the 218 patients included in this study, 141 (65%) were anterior stroke, and 77 were posterior stroke (35%) whereas 117 (53%) were male and 101 (47%) were female. The model built with original images reached 0.77 accuracy, while the model built with N4 bias corrected images reached 0.80 and the model built with images which were N4 bias corrected and then registered into a common space reached 0.83 accuracy values. CONCLUSION: Voxel wise dense prediction coupled with bias field correction to eliminate artificial signal increase and registration to a common space help models for better performance than using original images. Knowing the properties of target domain while designing deep learning models is important for the overall success of these models.

Evaluation of the relationship between sphenoid sinus morphology and area and volume by computed tomography.

OBJECTIVES: The aim of this study is to investigate the effect of sphenoid sinus pneumatization types, Onodi cell (OC), internal carotid artery (ICA), optic nerve (ON) on sinus volume and area on computed tomography (CT) images. METHODS: The CT images of 150 patients were evaluated. Sphenoid sinus pneumatization types, OC prevalence, protrusion and dehiscence of ICA and ON, the volume and area were evaluated. RESULTS: The sinus volume and area were statistically higher in patients with bilateral protrusion of ICA and ON then patients without protrusion of ICA and ON. The mean volume and area of sinus were 9949.4 ± 351.0 mm3 and 4570.9 ± 1604.9 mm2, respectively. The volume and area of sphenoid sinus did not differ significantly between groups with and without OC. The postsellar b type sphenoid sinus had the highest volume, while conchal type has the least volume. CONCLUSIONS: Bilateral protrusion and dehiscence of ICA and bilateral protrusion of ON caused a significant increase in the sphenoid sinus volume and area. The presence of ICA and ON, the pneumatization of the sinus is an anatomical structure that can affect the sinus volume and area. Before the operation, three-dimensional evaluation should be performed to determine whether these structures are bilateral/unilateral and it should be remembered that the sinus volume and area can change.

Comparison of the fibrosis degree using acoustic radiation force impulse elastography and diffusion-weighted magnetic resonance imaging in chronic hepatitis cases.

OBJECTIVE: The aim of this study was to investigate the correlation of fibrosis stages in cases of chronic hepatitis by comparing shear wave elastography and diffusion-weighted magnetic resonance imaging. METHODS: A total of 46 chronic hepatitis patients with an age range of 20-50 years were classified into three groups based on their fibrosis stages. Comparison group 1: the presence of fibrosis (S0 and S1≤); comparison group 2: the presence of significant fibrosis (≤S2 and S3≤); and comparison group 3: the presence of cirrhosis (≤S4 and S6). Shear wave velocities were measured by acoustic radiation force impulse elastography. Diffusion-weighted magnetic resonance imaging was performed on a 3.0 Tesla MRI device. RESULTS: In comparison group 1 (S0 and S1≤), the area under the curve, sensitivity, and specificity of acoustic radiation force impulse values were 0.784, 87, and 60%, respectively, while these values were 0.718, 80, and 66%, respectively, for apparent diffusion coefficient . In comparison group 2 (≤S2 and S3≤), the area under the curve, sensitivity, and specificity of acoustic radiation force impulse values were 0.917, 80, and 86%, respectively, and the apparent diffusion coefficient values were 0.778, 90, and 66%, respectively. In comparison group 3, the area under the curve, sensitivity, and specificity of acoustic radiation force impulse values were 0.977, 100, and 95%, respectively. There was no statistically significant difference between the apparent diffusion coefficient values of the cases in the three groups (p=0.132). CONCLUSION: Noninvasive methods are gaining importance day by day for staging hepatic fibrosis. Acoustic radiation force impulse elastography was evaluated as a more reliable examination than diffusion-weighted magnetic resonance imaging in revealing the presence of fibrosis, determining significant fibrosis, and diagnosing cirrhosis.

Evaluation of maxillary palatal process pneumatization by cone-beam computed tomography.

PURPOSE: The aim of this study is to investigate the pneumatization type of the palatal process (PTP) and angular and distance measurements of neighbouring structures on cone beam computed tomography (CBCT) images. MATERIALS AND METHODS: 400 maxillary sinuses (MS) of 200 patients (96 female; 104 male; mean age: 43.2) were retrospectively evaluated. PTP was divided into three as types 1,2 and 3 and evaluated at distances 4, 8, 16, and 24 mm posterior to incisive foramen. The sinus and alveolar ridge height, palatonasal recess angle (PRA) and palatal junction angle (PJA) were also measured and recorded. RESULTS: PTP I (101, 25.3%) was the most frequent type, followed by PTP II (95, 23.8%), and the least was PTP III (4, 1%). In patients with PTP I, the alveolar ridge height in the 4 mm and 8 mm group was significantly higher than in the patients with PTP II and III (p<0.05). In patients with PTP I, PRA in the 4 mm and 16 mm groups was significantly higher than in patients with PTP II and III (p<0.05). Sinus and alveolar ridge height, PRA and PJA did not differ significantly between the right and left sides in the 4 mm, 8 mm, 16 mm, and 24 mm groups (p>0.05). CONCLUSION: Knowing the anatomy of the MS is very important for a successful surgical procedure in this area. Anatomy and pathology of the MS can be understood more clearly in CBCT.

Comparison of the fibrosis degree using acoustic radiation force impulse elastography and diffusion-weighted magnetic resonance imaging in chronic hepatitis cases

SUMMARY OBJECTIVE: The aim of this study was to investigate the correlation of fibrosis stages in cases of chronic hepatitis by comparing shear wave elastography and diffusion-weighted magnetic resonance imaging. METHODS: A total of 46 chronic hepatitis patients with an age range of 20-50 years were classified into three groups based on their fibrosis stages. Comparison group 1: the presence of fibrosis (S0 and S1≤); comparison group 2: the presence of significant fibrosis (≤S2 and S3≤); and comparison group 3: the presence of cirrhosis (≤S4 and S6). Shear wave velocities were measured by acoustic radiation force impulse elastography. Diffusion-weighted magnetic resonance imaging was performed on a 3.0 Tesla MRI device. RESULTS: In comparison group 1 (S0 and S1≤), the area under the curve, sensitivity, and specificity of acoustic radiation force impulse values were 0.784, 87, and 60%, respectively, while these values were 0.718, 80, and 66%, respectively, for apparent diffusion coefficient . In comparison group 2 (≤S2 and S3≤), the area under the curve, sensitivity, and specificity of acoustic radiation force impulse values were 0.917, 80, and 86%, respectively, and the apparent diffusion coefficient values were 0.778, 90, and 66%, respectively. In comparison group 3, the area under the curve, sensitivity, and specificity of acoustic radiation force impulse values were 0.977, 100, and 95%, respectively. There was no statistically significant difference between the apparent diffusion coefficient values of the cases in the three groups (p=0.132). CONCLUSION: Noninvasive methods are gaining importance day by day for staging hepatic fibrosis. Acoustic radiation force impulse elastography was evaluated as a more reliable examination than diffusion-weighted magnetic resonance imaging in revealing the presence of fibrosis, determining significant fibrosis, and diagnosing cirrhosis.

Cone beam computed tomographic evaluation of infraorbital canal protrusion into the maxillary sinus and its importance for endoscopic surgery

Abstract Objective: The aim of this retrospective study is to investigate the prevalence of Infraorbital Canal Protrusion (ICP) degree into the maxillary sinus and its relationship with variations in adjacent structures on Cone Beam Computed Tomography (CBCT) images. Methods: 350 CBCT images (700 Infraorbital Canal [IC]) were evaluated retrospectively. ICP was divided into 3 subtypes according to the protrusion degree. The correlation between IC types and variations in adjacent anatomical structures (Haller cell, middle nasal concha pneumatization, maxillary sinus mucosal thickening and septa) was evaluated. The distance between Infraorbital Canal and Cnine Root (IC-CR) was also measured. For type 3, measurements were performed on IC as the length of the bony septum from the IC to the Mxillary Sinus Wall (IC-MSW), the distance from the inferior orbital rim, where the IC begins to protrude into the maxillary sinus (IOR-ICP), the vertical distance from the IC to the Maxillary Sinus Roof (IC-MSR) and Floor (IC-MSF). Results: The prevalence of type 1, 2 and 3 was 62.9%, 29.1%, and 8% respectively. IC-CR was 10.2, 10.7 and 11.4 mm in type 1, 2 and 3, respectively. IC-MSW, IOR-ICP, IC-MSRand floor IC-MSF was 3.8, 10.9, 7.4 and 27.7mm, respectively. On the right and left side, statistically significant correlation was found between IC types and the presence of the Haller cell and sinus septa. But there was no significant correlation between IC types and middle concha pneumatization. Conclusion: Accurate diagnosis of ICP is very important in preventing infraorbital nerve damage in surgical procedures to be performed in the maxillary region. The results of this study could be a guide for surgical planning in this region. Level of evidence: Retrospective study.

Cone beam computed tomographic evaluation of infraorbital canal protrusion into the maxillary sinus and its importance for endoscopic surgery.

OBJECTIVE: The aim of this retrospective study is to investigate the prevalence of Infraorbital Canal Protrusion (ICP) degree into the maxillary sinus and its relationship with variations in adjacent structures on Cone Beam Computed Tomography (CBCT) images. METHODS: 350 CBCT images (700 Infraorbital Canal [IC]) were evaluated retrospectively. ICP was divided into 3 subtypes according to the protrusion degree. The correlation between IC types and variations in adjacent anatomical structures (Haller cell, middle nasal concha pneumatization, maxillary sinus mucosal thickening and septa) was evaluated. The distance between Infraorbital Canal and Cnine Root (IC-CR) was also measured. For type 3, measurements were performed on IC as the length of the bony septum from the IC to the Mxillary Sinus Wall (IC-MSW), the distance from the inferior orbital rim, where the IC begins to protrude into the maxillary sinus (IOR-ICP), the vertical distance from the IC to the Maxillary Sinus Roof (IC-MSR) and Floor (IC-MSF). RESULTS: The prevalence of type 1, 2 and 3 was 62.9%, 29.1%, and 8% respectively. IC-CR was 10.2, 10.7 and 11.4 mm in type 1, 2 and 3, respectively. IC-MSW, IOR-ICP, IC-MSR and floor IC-MSF was 3.8, 10.9, 7.4 and 27.7 mm, respectively. On the right and left side, statistically significant correlation was found between IC types and the presence of the Haller cell and sinus septa. But there was no significant correlation between IC types and middle concha pneumatization. CONCLUSION: Accurate diagnosis of ICP is very important in preventing infraorbital nerve damage in surgical procedures to be performed in the maxillary region. The results of this study could be a guide for surgical planning in this region. LEVEL OF EVIDENCE: Retrospective study.

Evaluation of morphological variations of petrotympanic fissure using computed tomography imaging of the temporal bone.

PURPOSE: Petrotympanic fissure (PF) is important for both dentists and otolaryngologists to know the temporal anatomy well especially for pre-surgical radiological evaluations. Computed tomography (CT) is indispensable method for temporal bone imaging. The purpose of this study was to evaluate PF morphology and position using CT. METHODS: CT scans of 300 patients (600 PFs) were retrospectively evaluated. PF types were recorded by dividing into 3 groups (Type 1,2 and 3). Length of the mandibular fossa (MF) and PF, vertical diameter (VD) of the PF at the MF level, midpoint and tympanic cavity (TC) level were measured. PF position types were subdivided as low, midline and high. RESULTS: Type 1, 2 and 3 was found in 18.7%, 51.5% and 29.8% of the cases, respectively. The mean length of the MF and PF was 18.33 mm and 3.77 mm, respectively. The mean VD of the PF at the MF level, midpoint and TC level was 1.71, 0.98 and 0.97 mm, respectively. The low, midline and high position of PF was observed 14.5%, 54.3% and 31.2% of the cases, respectively. CONCLUSION: Length of the MF and PF in males was significantly higher than females. VD of the PF at the MF level in Type 1 and Type 3 was significantly higher than type 2. In type 1,VD of the PF at the midpoint was significantly higher than type 2 and type 3. VD of the PF at the TC level in Type 1 and Type 3 was significantly higher than type 2.

Efficacy of low dose and ultra-low dose on the visibility of peri-implant fenestration and dehiscences: a computed tomography study.

PURPOSE: This study aimed to evaluate the visibility of peri-implant fenestration and dehiscences on computed tomography (CT) images taken with 2 different doses. MATERIAL AND METHODS: The defects were created on the apical of 6 implants randomly selected from 20 titanium implants placed in the ribs, and dehiscences were created on the cervical of 8 implants. No defects were created around 6 implants. Macroscopic analysis of the implanted ribs was accepted as the gold standard. From the samples, images were taken by using both ultra-low dose (80 kVp, 50 mA, 1.25 mm slice thickness) and low dose (100 kVp, 50 mA, 1.25 mm slice thickness) protocols in CT. The images obtained were evaluated using a 5-point scale. RESULTS: No significant difference was found between the area under the receiver operating characteristic of ultra-low dose protocol and low dose protocol in both defects based on the Wilcoxon test (p > 0.05). CONCLUSIONS: The ultra-low dose protocol could be applied by adhering to the "as low as reasonably achievable" principle in the diagnosis of peri-implant defects.

Volumetric and morphological analysis of condyle and glenoid fossa on computed tomography.

AIM: The aim of this study was to evaluate temporomandibular joint (TMJ) condyle and glenoid fossa morphology with measurements on Computed Tomography (CT) and volumetric analysis using InVesalius software program. MATERIALS AND METHODS: 250 condyles in 125 patients (mean age: 40.64) was evaluated on CT. Length, width, and height of the condyle, condylar volume, the thickness of glenoid fossa (TGF), condyle surface area, anterior space (AS), superior space (SS), and posterior space (PS) were measured in this study. Two left and right sides of the jaw have been measured. Linear measurements were performed with the image analysis program (Image J, 1.4 v version, National Institutes of Health, Bethesda, MD). Volume and surface area measurements were performed with InVesalius software (CTI, Campinas, SãoPaulo, Brazil). RESULTS: To compare the dimensions of the condyle between males and females, there was only a significant difference in left AS and SS and no significant difference was found between males and females in other measured factors. There was a significant difference between the age groups and left SS. A significant difference was also found between the age groups and condylar height, condyle surface area, and condylar volume on both right and left sides. CONCLUSION: Evaluation of condylar morphology is important to assess the TMJ anomalies and bony changes. This study showed no significant differences between gender and all measured factors except in the left AS and SS. However, age factor had a major effect on the morphology.

Bibliometric Analysis of 50 Most Cited Articles on Odontomas

Abstract Objective: To identify the citation features and review articles on odontomas using bibliometric analysis. Material and Methods: A list of studies about odontoma was obtained by searching using the Scopus database. Abstracts or full texts were read and evaluated. After then, 50 most cited articles were achieved. Studies were categorized as citation numbers, citation density, journal name, article type, the affiliation of the first author and publication year. Descriptive statistics were used to analyze the results. Results: The most frequently cited article received 358 citations, while the least frequently cited article received 42 with a mean of 94.3 citations per article. The mean citation density was 5.13. The study with the highest citation density (12.31) was published in 2006. The highest citation number was found in the 2000s following the 1990s. The 50 most cited articles were published from 1971 to 2011, with 84% (42 of 50) published after 1990. USA (n = 9) and Brazil (n = 6) were the two most contributing countries. According to article type, there were eight (16%) review articles. Conclusion: The USA found to have a strong influence on research about odontoma, followed by Brazil. All researches were reported in English, and most of them were published in good quality journals (AU).

Determining the Thyroid Gland Volume Causing Tracheal Compression: A Semiautomated 3D CT Volumetry Study.

Background and objectives: Increased thyroid gland volume (TV) may bring about tracheal compression, which is one of the causes of respiratory distress. The aim of this study was to investigate the relationship between TV and the severity of tracheal compression independent of patients' symptoms using semiautomated three-dimensional (3D) volumetry (S3DV) reconstructed from computed tomography (CT) scans. Cut-off TVs leading to different levels of tracheal narrowing were evaluated. Materials and Methods: One hundred sixty-three contrast-enhanced head and neck CT examinations were retrospectively assessed. TVs were measured by S3DV. The degree of tracheal compression was measured at the point where the greatest percent reduction in the cross-sectional area of the trachea adjacent to the thyroid gland was observed. To determine the severity of compression, the tracheal compression ratio (TCR) was defined (TCR = A1 (the narrowest cross-sectional area of trachea)/A2 (the largest cross-sectional area of trachea)). Results: The mean tracheal narrowing was 15% (TCR = 0.85 ± 0.15) in the study population. Patients with more than 15% tracheal compression had significantly higher TV values than those with less than 15% tracheal compression (p < 0.001). In addition, a significant correlation was found between TV and tracheal compression (p < 0.001). Moreover, the receiver operating characteristic (ROC) curve analysis revealed that the cut-off levels for TV that predict a tracheal narrowing of 10%, 20%, 30%, and 40% were 19.75 mL, 21.56 mL, 24.54 mL, and 30.29 mL, respectively (p < 0.05). Conclusions: This study objectively demonstrated that larger thyroid glands cause more severe compression on the trachea. The results may be helpful during the decision-making process for thyroidectomies to be performed due to compression symptoms.

Imaging Findings of Jugular Foramen Meningocele in a Neurofibromatosis Type 1 Patient.

Neurofibromatosis type I (NF1) is a neurocutaneous disorder that involves autosomal dominant transmission. Skull defects, including sphenoid dysplasia and calvarial defects, are a rare finding in patients with NF1. Spinal meningocele and sphenoid wing dysplasia have been identified in NF1 but the occurrence of meningoceles at the skull base is extremely rare. A rare instance of jugular foramen meningocele being identified in an NF1 patient on imaging is described in this paper. To the best of our knowledge, only two such cases have been reported in the English literature.