Radiomics-based machine learning in the differentiation of benign and malignant bowel wall thickening radiomics in bowel wall thickening.

PURPOSE: To distinguish malignant and benign bowel wall thickening (BWT) by using computed tomography (CT) texture features based on machine learning (ML) models and to compare its success with the clinical model and combined model. METHODS: One hundred twenty-two patients with BWT identified on contrast-enhanced abdominal CT and underwent colonoscopy were included in this retrospective study. Texture features were extracted from CT images using LifeX software. Feature selection and reduction were performed using the Least Absolute Shrinkage and Selection Operator (LASSO). Six radiomic features were selected with LASSO. In the clinical model, six features (age, gender, thickness, fat stranding, symmetry, and lymph node) were included. Six radiomic and six clinical features were used in the combined model. Classification was done using two machine learning algorithms: Support Vector Machine (SVM) and Logistic Regression (LR). The data sets were divided into 80% training set and 20% test set. Then, training took place with all three datasets. The model's success was tested with the test set consisting of features not used during training. RESULTS: In the training set, the combined model had the best performance with the area under the curve (AUC) value of 0.99 for SVM and 0.95 for LR. In the radiomic-derived model, the AUC value is 0.87 in SVM and 0.79 in LR. In the clinical model, SVM made this distinction with 0.95 AUC and LR with 0.92 AUC value. In the test set, the classifier with the highest success distinguishing malignant wall thickening is SVM in the radiomic-derived model with an AUC value of 0.90. In other models, the AUC value is in the range of 0.75-0.86, and the accuracy values are in the range of 0.72-0.84. CONCLUSION: In conclusion, radiomic-based machine learning has shown high success in distinguishing malignant and benign BWT and may improve diagnostic accuracy compared to clinical features only. The results of our study may help ensure early diagnosis and treatment of colorectal cancers by facilitating the recognition of malignant BWT.

Optical coherence tomography and shear wave elastography findings in Graves ophthalmopathy.

PURPOSE: The main feature of Graves ophthalmopathy (GO) is revealed by determining the activity and severity of the disease. We aimed to evaluate the use of imaging methods can also provide additional information about the severity of this disease. METHODS: Optical coherence tomography (OCT) and shear wave elastography (SWE) findings were compared in 32 patients with mild GO group and in the healthy control group. Measuring for TSH receptor antibody (TRAb) serum level is used third-generation assay. RESULTS: In Graves group, optic nerve sheath diameter (ONSD) values were increased in both eyes (p < 0.001, p < 0.001). SWE measurements showed a significant increase both eye optic nerve (ON) and right eye soft tissue elasticity values in GO group (p < 0.001, p < 0.001, p < 0.001, respectively). There was a significant thinning in left temporal retinal nerve fiber layer (RNFL) thickness and left RNFL peripapillary thickness in GO group (p < 0.001, p < 0.025, respectively). There was a correlation between left eye OCT and SWE findings. Also, there was a significant difference between the median left eye ON and soft tissue elasticity results in the TRAb-positive GO group (p = 0.049, p = 0.048, respectively). CONCLUSION: SWE measurements showed a significant increase both eyes ONSD, ON and right eye soft tissue elasticity values in GO group. GO group was significant thinning in some left eye regions in OCT measurements. There was a correlation between left eye OCT and SWE findings. In addition to clinical activity score and TRAb, SWE and OCT can be used to monitor in patients with GO.

Preoperative assessment of grade, T stage, and lymph node involvement: machine learning-based CT texture analysis in colon cancer.

PURPOSE: To investigate whether texture analysis of primary colonic mass in preoperative abdominal computed tomography (CT) scans of patients diagnosed with colon cancer could predict tumor grade, T stage, and lymph node involvement using machine learning (ML) algorithms. MATERIALS AND METHODS: This retrospective study included 73 patients diagnosed with colon cancer. Texture features were extracted from contrast-enhanced CT images using LifeX software. First, feature reduction was performed by two radiologists through reproducibility analysis. Using the analysis of variance method, the parameters that best predicted lymph node involvement, grade, and T stage were determined. The predictive performance of these parameters was assessed using Orange software with the k-nearest neighbor (kNN), random forest, gradient boosting, and neural network models, and their area under the curve values were calculated. RESULTS: There was excellent reproducibility between the two radiologists in terms of 49 of the 58 texture parameters that were subsequently subject to further analysis. Considering all four ML algorithms, the mean AUC and accuracy ranges were 0.557-0.800 and 47-76%, respectively, for the prediction of lymph node involvement; 0.666-0.846 and 68-77%, respectively, for the prediction of grade; and 0.768-0.962 and 81-88%, respectively, for the prediction of T stage. The best performance was achieved with the random forest model in the prediction of LN involvement, the kNN model for the prediction of grade, and the gradient boosting model for the prediction of T stage. CONCLUSION: The results of this study suggest that the texture analysis of preoperative CT scans obtained for staging purposes in colon cancer can predict the presence of advanced-stage tumors, high tumor grade, and lymph node involvement with moderate specificity and sensitivity rates when evaluated using ML models.

Could the Cerebral Involvement of COVID-19 Disease be Related to Microstructural Changes that are not Reflected in Conventional MRI Images?

In patients with COVID-19, neurodegeneration may develop before clinical symptoms appear. Diffusion-weighted (DW) MRI is an important technique for analyzing microstructural changes such as gliosis. In this study, a quantitative evaluation of microstructural changes in the brain with apparent diffusion coefficient (ADC) values in patients presenting with a headache after the COVID-19 disease was analyzed and compared. DW MR images of patients of 20 COVID-19 patients (13 females, 7 males) who required imaging due to headache; 20 controls (16 females, 4 males) were retrospectively reevaluated. ADC measurements were taken from 16 regions of the brain, including right and left symmetrical in patients with COVID-19 infections and control groups. All regions of interest (ROIs) were taken from the hypothalamus, parahippocampus, thalamus, corpus striatum, cingulate gyrus, occipital gyrus, dentate nucleus, and medulla oblongata posterior. ADC values in the dentate nucleus right (784.6 ± 75.7 vs. 717.25 ± 50.75), dentate nucleus left (768.05 ± 69.76 vs. 711.40 ± 52.99), right thalamus (731.15 ± 38.14 vs. 701.60 ± 43.65), left thalamus (744.05 ± 39.00 vs. 702.85 ± 28.88), right parahippocampus (789.10 ± 56.35 vs. 754.75 ± 33.78), right corpus striatum (710.00 ± 39.81 vs. 681.55 ± 39.84) were significantly higher than those in the control group. No significant changes were observed in other areas. A significant increase in ADC values at many levels in the brain in patients with COVID-19 disease and headache was observed. Thus, this study indicates that cerebral involvement in COVID-19 disease may be related to microstructural changes that are not reflected in conventional MRI images.

Ultrasonographic shear wave elastography of the thyroid in patients with sickle cell anemia.

Background: Although thyroid radiology has been conducted in patients with sickle cell anemia (SCA), to our knowledge, there is no report of thyroid gland assessment using ultrasonographic shear wave elastography (US-SWE). Objectives: To determine values for ultrasonographic US-SWE of the thyroid in patients with SCA and correlations between thyroid elasticity and biochemical variables used to evaluate thyroid function. Methods: Prospective case-control observational study of 36 patients with SCA and 33 healthy volunteer controls. US-SWE measurements of thyroid gland parenchyma and biochemical parameters of the participants were obtained and compared, and the diagnostic accuracy of elasticity was determined. Results: The thyroid volume was smaller in patients with SCA than that in controls (P = 0.001). Compared with the controls, the patients with SCA had significantly lower serum levels of free triiodothyronine (fT3) (P = 0.004) and thyroglobulin (Tg) (P = 0.001) and significantly higher levels of thyroid-stimulating hormone (P = 0.028). Thyroid stiffness was significantly higher in the left lobe (LL) of the patients with SCA than in the controls (P = 0.003). In the patients with SCA, we found a significant correlation between right lobe (RL) and LL stiffness and serum levels of Tg (RL [r = -0.439] and LL [r = -0.484]; P = 0.021) and fT3 (RL [r = -0.463] and LL [r = -0.386]; P = 0.012). Receiver operating characteristic (ROC) curve analysis of thyroid elasticity that represented a diagnosis of SCA found a cutoff of >7.31 kPa, a sensitivity of 52.0%, and a specificity of 72.0% for the RL (P = 0.316, area under the curve [AUC] 0.570), and a cutoff of >8.06 kPa, a sensitivity of 58.0%, and a specificity of 84.0% for the LL (P = 0.011, AUC 0.680). Conclusions: US-SWE can be used to follow up thyroid changes in patients with SCA.

Diffusion-Weighted MRI Findings of Caudate Nucleus and Putamen in Patients With Obsessive-Compulsive Disorder.

Objective The purpose of this study was to establish the diffusion-weighted magnetic resonance imaging (DW-MRI) findings of the caudate nucleus and putamen in patients with obsessive-compulsive disorder (OCD) and to obtain new information on the etiopathogenesis of OCD, which is still unclear. Methods The study comprised 20 patients with OCDs and 20 healthy volunteers. In these cases, DW-MRI and diffusion-weighted echo-planar images (DW-EPI) at b600 and b1000 gradient values were taken and the measurements were made using the apparent diffusion coefficient (ADC) maps of each group at b600 and b1000 values from the caudate nucleus and putamen. Results When the DW-MRI examination in patients with OCD was compared with the control group, the mean ADC values in the caudate nucleus and putamen were not found to have statistically significantly changed. In addition, there were no significant differences regarding the right and left caudate nuclei and putamen ADC values at the b600 and b1000 in the patients with OCD or the control group. Conclusion There are still many unknowns about the neurobiology of OCD. When the DW-MRI examination of the patients with OCD was compared with the control group in our study, no significant difference was found between the ADC values of the caudate nucleus and putamen. Further studies are required for this present study on DW-MRI in patients with OCD to be meaningful.

Comparative study of the volume of the temporal lobe sections and neuropeptide effect in Alzheimer's patients and healthy persons.

AIM: The aim of this study was to make a volumetric comparison of some medial temporal lobe structures and neuropeptides between the patients of Alzheimer's disease (AD) and healthy individuals. METHOD: The study comprised of a group of patients diagnosed with mild AD (n:15) and a Control group (n:15) (16 females, 14 males, mean age:72.90 ± 4.50). Voxel-based morphometry and MRICloud analyses were performed on the MR images taken in 3D measurements of gray matter volumes of all subjects. Following a 10-minute hug test, blood samples were taken from all participants for oxytocin (OT) and arginine vasopressin (AVP) analyses. RESULTS: The patient group had a statistically lower right hippocampus volume (p = 0.004) and OT values (p = 0.028) than the Control group. OT signal values increased with a volume increase in the right parahippocampal gyrus (PHG_R), and OT conc. and AVP conc. values increased with increasing volume of the PHG_R. CONCLUSION: It is suggested that the right hippocampus, right fusiform gyrus, left amygdala, left parahippocampal gyrus, and left entorhinal cortex atrophies can be used as predictors in the early diagnosis of AD. The positive correlation between PHG_R and neuropeptides showed the need to investigate the PHG and OT function more deeply.

Evaluation of dural venous sinuses and confluence of sinuses via MRI venography: anatomy, anatomic variations, and the classification of variations.

PURPOSE: We aimed to determine the anatomical variations more comprehensively particularly at the level of superior sagittal sinus (SSS), confluence of sinuses (CS), transverse sinuses (TS), straight sinuses (SS) and occipital sinuses (OS) with the help of the images obtained via MRI venography, and to contribute to the classification efforts. METHODS: In our retrospective study, we evaluated 211 patients who admitted to our hospital with various complaints and cerebral MRI venography has been performed. All investigations were performed by using 1.5-T MRIscanner (Achiva, Philips) with a VEN-3D -PCA MR venous angiography technique. Section thickness was 0.8 mm and axial plane was used. Other parameters were as follows: 17/7.1 (TR/TE), flip angle, 10.00, FOV, 220-mm, and matrix 244x140. RESULTS: We divided our cases into 3 types but we increased the number of subgroups. Type I was divided into 4 subgroups (Type IA, IB, IC, ID), Type II into 9 (Type IIA1, IIA2, IIB1, IIB2, IIC, IID1, IID2, IIE1, IIE2) and Type III into 2 (Type IIIA, IIIB). Type I constitutes a 26.06% of whole cases, and Type II 59.71%, Type III 14.21%. In our cases R-TS wasn't revealed in 10 cases (4.73%) whereas in 37 cases (17.53%) it was hypoplastic. L-TSwasn't shown in 26 cases (12.32%) and in 85 cases (49.09%) it was hypoplastic. R-Sig S wasn't revealed in 7 (3,31%) and was hypoplastic in 34 (16.11%) whereas L-Sig S wasn't present in 2 (0.94%) and hypoplastic in 72 (34.12%). Among these cases 14 had bilateral hypoplastic TS (6.63%). In cases with hypoplastic TS or Sig S, as an alternative pathway 30 patients had OS (14.21%). Two of these patients had double OS. CONCLUSION: Our wish is to contribute to the efforts of clarifying and classifying the intracranial venous structures and their anatomical variations. We hope our study enlightens a path in this field for future studies.

Radiological Imaging of Rare Intracranial Complications Secondary to Otitis Media and Mastoiditis.

Acute otitis media used to cause fatal results because of its intracranial complications before the introduction of potent and effective antibiotics. After the introduction of antibiotics, complications have started to be observed more frequently as a result of chronic otitis media and especially in children. Because clinical findings changed and became indistinct, the diagnosis of otitis and mastoiditis has been made occasionally with imaging findings only after complications occurred. Multidetector computed tomography and magnetic resonance imaging are efficient and sufficient methods in the rapid diagnosis and should be immediately referred methods.

Antronasal Polyp Extending to Orbital Fossa.

Sinonasal infections and nasal polyps can be taken as 2 components of a disease. Polyps due to chronic inflammations of nasal cavity and sinuses are not rare. They may present with various clinical signs and symptoms, while the secondary complications may cause serious problems. They are most commonly treated medically, although surgery is the therapy of choice in some conditions. The complications can be listed as mucocele formation, orbital inflammation, intracranial extension by erosion of the boney structures.

Congenital abnormalities of the ribs: evaluation with multidetector computed tomography.

OBJECTIVE: To evaluate congenital abnormalities of ribs using multidetector computed tomography. METHODS: The retrospective study was conducted at Mustafa Kemal University Research Hospital, Hatay, Turkey and comprised data of patients aged 1-45 years who attended the Radiology Department for computed tomography of the thorax between January 2010 and July 2013. Multiplanar reconstructions, maximum intensity projections, and 3-dimensional images were acquired to investigate numerical and structural abnormalities of the ribs of the patients who underwent multidetector computed tomography for a variety of indications. RESULTS: The study comprised 650 patients. Of them, 231(35.5%) were female and 419(64.5%) male. The overall mean age was 20.9± 5.1years. However, data of 90(13.8%) patients was excluded from cervical rib evaluation and of 120(18.5%) from lumbar rib evaluation as these regions were out of the section because of the positioning. Finally, 560(86.5%) patients were included in the cervical rib evaluations, and 530(81.5%) in the lumbar rib evaluations. All the 650(100%) patients were included in the thoracic rib evaluations. Numerical abnormalities were observed in cervical ribs in 19(3.6%), in thoracic ribs in 1(0.15%) and in lumbar ribs in 7(1.3%) cases. The structural abnormalities were bifid rib in 44(6.7%) and fused type in 17(2.6%) cases. CONCLUSIONS: Multidetector computed tomography enabled evaluation of the thoracic cage as a whole.

Aberrant Internal Carotid Artery in the Tympanic Cavity.

OBJECTIVES: Presence of aberrant internal carotid artery (ICA) in the tympanic cavity is a very rare case and therefore the diagnosis is a challenge. Here, the authors aimed to address the importance of the diagnosis since the intervention to the middle ear and implants is increasing in number and this condition may lead to life-threatening bleeding. METHODS: Between 2012 and 2016, among the patients referred to the authors' Radiology Department from the Department of Otolaringology for the evaluation of the temporal region for various indications, the authors reported this anomaly in 6 patients and multidetector computerized tomography of these 6 patients and magnetic resonance imaging of 2 were assessed in detail. RESULTS: The mean age of the 6 patients was 28.8 and aberrant ICA abnormality was observed in 2 patients bilaterally and 4 patients unilaterally on the right side. In 1 patient ICA was not totally regressed and observed as hypoplastic. In one of the patients, dehiscence was evident between ICA and the cochlea. Moreover, in 1 patient the contralateral ICA was not observed. CONCLUSION: Although rare, aberrant ICA is an abnormality that should be kept in mind by the clinicians and the radiologists, since it leads to abundant bleeding when undiagnosed before the surgical interventions.

Two cases with giant pseudo-aneurysm of vertebral artery secondary to shrapnel injury.

INTRODUCTION: Due to their locations, vertebral arteries (VA) are structures that are rarely injured after traumas. Formation of vertebral pseudo-aneurysm (PA) because of pieces of shrapnel is also rare. It causes clinical findings like cervical mass after the injury CASES PRESENTATION: Two Syrian 12- and 17-year-old male patients were admitted to the Department of Ear, Nose and Throat with the complaint of swelling in the left lower cervical region. In their USG examination which was ordered to investigate the cervical lesion, a lesion consistent with PA which shows a prominently thick wall structure due to circumferential thrombus formation and fibrotic tissue, chaotic flow, and ying-yang appearance in the centrally located cavity of the lesion in a color Doppler examination was detected. Later, multi-detector computed tomography angiography (MDCTA) was planned to demonstrate pseudo-aneurysms (PAs). CONCLUSION: Because there was no report on the development of giant pseudo-aneurysms secondary to shrapnel injury to date and because we thought these cases are demonstrative, we found the cases suitable for presenting as case reports.

Primary cyst hydatid in the neck; report of one case.

Hydatid cyst is a parasitic disease that has been recognized endemically in many countries. Although the liver and lung are the most common organs involved by the disease, it may appear rarely in other tissues as a primary disease. In the ultrasonography of the neck taken from a 17 year old case who attended with a complaint of swelling in the neck, a partly regular, bounded cystic lesion of 33x28 mm in size was reported. When the cyst was thought to be hydatid during surgical exploration, this diagnosis was confirmed by histopathological verification of the specimen obtained. Whole abdomen ultrasonography and PA Chest Radiography were taken in order to determine whether there was another focus during the postoperative period. The Echinococcus ELISA test was performed as an immunological parameter. Treatment with Albendazole began after diagnosis during the postoperative period. Although hydatid cyst most commonly involves the liver and lung, it may be detected in all body tissues. Therefore hydatid cyst must be considered in the differential diagnosis in cystic lesions that are rarely encountered in body localizations in human, living in endemic regions.

Age-related metabolic changes in the corpus callosum: assessment with MR spectroscopy.

PURPOSE: The aim of this study was to examine metabolite changes in different parts of the corpus callosum (CC), and to relate these changes to different age groups using magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: A total of 76 healthy subjects participated in the study with MRS analyses (39 females and 37 males). Subjects were grouped by age into four groups, in increasing order: Groups 1, 2, 3, and 4. Single-section 2D multivoxel spectroscopy was performed using chemical-shift imaging techniques. The voxels were placed on the rostrum, genu, corpus, and splenium of the CC. Peak metabolite ratios of N-acetylaspartate (NAA)/choline (Cho), NAA/creatine (Cr), and Cho/Cr were calculated from the rostrum, genu, body, and splenium. One way analysis of variance test was performed for the detection of changes in different age groups. Pearson correlation test was performed for correlation of metabolite ratio related to age. RESULTS: Statistically significant differences were found for NAA/Cho ratios for the rostrum, corpus, and splenium, and NAA/Cr ratios for the corpus and splenium between Groups 1 and 2, Groups 1 and 3, and Groups 1 and 4. Metabolite ratios of the corpus and splenium were similar. This similarity was also valid for parts of the rostrum and genu. CONCLUSION: Metabolite ratios in the CC are influenced by age. Age-related changes and regional metabolite levels may cause these alterations. Analyses of the CC may be informative for the evaluation of white matter. MRS may help to demonstrate metabolite levels and ratios of the CC.