A comparative study of machine learning methods for predicting the evolution of brain connectivity from a baseline timepoint.

BACKGROUND: Predicting the evolution of the brain network, also called connectome, by foreseeing changes in the connectivity weights linking pairs of anatomical regions makes it possible to spot connectivity-related neurological disorders in earlier stages and detect the development of potential connectomic anomalies. Remarkably, such a challenging prediction problem remains least explored in the predictive connectomics literature. It is a known fact that machine learning (ML) methods have proven their predictive abilities in a wide variety of computer vision problems. However, ML techniques specifically tailored for the prediction of brain connectivity evolution trajectory from a single timepoint are almost absent. NEW METHOD: To fill this gap, we organized a Kaggle competition where 20 competing teams designed advanced machine learning pipelines for predicting the brain connectivity evolution from a single timepoint. The teams developed their ML pipelines with combination of data pre-processing, dimensionality reduction and learning methods. Each ML framework inputs a baseline brain connectivity matrix observed at baseline timepoint t0 and outputs the brain connectivity map at a follow-up timepoint t1. The longitudinal OASIS-2 dataset was used for model training and evaluation. Both random data split and 5-fold cross-validation strategies were used for ranking and evaluating the generalizability and scalability of each competing ML pipeline. RESULTS: Utilizing an inclusive approach, we ranked the methods based on two complementary evaluation metrics (mean absolute error (MAE) and Pearson Correlation Coefficient (PCC)) and their performances using different training and testing data perturbation strategies (single random split and cross-validation). The final rank was calculated using the rank product for each competing team across all evaluation measures and validation strategies. Furthermore, we added statistical significance values to each proposed pipeline. CONCLUSION: In support of open science, the developed 20 ML pipelines along with the connectomic dataset are made available on GitHub (https://github.com/basiralab/Kaggle-BrainNetPrediction-Toolbox). The outcomes of this competition are anticipated to lead the further development of predictive models that can foresee the evolution of the brain connectivity over time, as well as other types of networks (e.g., genetic networks).

Is regression of catheter-related epidural granuloma possible? A case report.

Epidural granuloma may develop as a complication during long-term use of intrathecal analgesics. To the best of our knowledge, it is not mentioned in the current literature that discontinuation of therapy may cause a regression of epidural granulation and clinical symptoms. In this case, we aimed to present spontaneous regression of epidural granuloma within 2 months after removal of epidural port.

Anatomic Variations of Paranasal Region in Migraine.

PURPOSE: To assess the incidence of anatomical variations of the paranasal region on computed tomography in migraine patients compared with control subjects. METHODS: Paranasal computed tomography scans of 2 groups consisting of 50 migraine patients and 50 control subjects were evaluated, retrospectively. The presence of anatomic variations and the unilateral or bilateral presence of these variations were noted. Appropriate statistical tests were performed to compare the migraine and control groups, using a threshold P value of 0.05 for statistical significance. RESULTS: The migraine group included 39 female and 11 male patients with mean age of 39.9 (range: 18-65) years. The control subject group included 29 female and 21 male patients with mean age of 41.9 (range: 18-73) years. Anatomic variations noted included nasal septal deviation and spur, paradoxical curvature of middle concha, agger nasi cell, infraorbital ethmoidal (Haller) cells, sphenoethmoidal (Onodi) cells, supraorbital ethmoidal air cells, concha bullosa, uncinate bulla, and pneumatized crista galli. Of these variations, only the presence of Haller cells was statistically significantly higher in the migraine group compared with controls (P = 0.007). The unilateral presence of Onodi (P < 0.001), unilateral presence of supraorbital ethmoidal air cells (P = 0.012), and bilateral presence of concha bullosa (P = 0.016) were statistically significantly higher in the migraine group. There was no statistically significant difference between the unilateral or bilateral presence of Haller cells in migraine patients compared with controls (P > 0.05). CONCLUSION: Radiographic assessment of the paranasal sinuses is useful to elucidate potential points of pathology in migraine patients. The specific contribution of Haller cells to migraine headache symptoms and safe methods for surgical decompression warrant further study.

Axial Mesodermal Dysplasia Complex with a Unique Abnormal Course of Vestibulocochlear Nerve.

Axial mesodermal dysplasia complex (AMDC) is a combination of multiple congenital malformations arising due to the mesodermal cell migration, neural tube fusion, and rhombencephalon segmentation. Here, we present the imaging findings of a 15-year-old boy with AMDC who has bilateral inner ear malformations associated with a vestibulocochlear nerve extending to Meckel cave, cystic lesion in prepontine cisterna, cervical vertebral segmentation anomalies, and maxillar bone anomalies.

Variations in the origins of the thyroid arteries on CT angiography.

OBJECTIVE: To investigate the anatomical variations in the origins of the thyroid arteries on CT angiography images. METHODS: The presence and the origins of the superior thyroid artery, the inferior thyroid artery, and the thyroidea ima artery were retrospectively evaluated based on carotid CT angiography examinations. The bifurcation level of the common carotid artery with respect to the cervical vertebrae and disc spaces was also determined. A total of 640 patients were included in the study. RESULTS: The right and left superior thyroid arteries arose from the external carotid artery in 413 (64.5%) and 254 (39.7%) patients, from the bifurcation of the common carotid artery in 131 (20.5%) and 148 (23.1%) patients, and from the common carotid artery in 90 (14.1%) and 226 (35.3%) patients, respectively. We could not observe the right and the left superior thyroid arteries in 6 (0.9%) and 12 (1.9%) of the patients, respectively. However, the right and left inferior thyroid arteries were not identified in 14 (2.2%) and 45 (7%) of the patients, respectively. The thyroidea ima artery was detected in 2.3% of the patients. CONCLUSION: The visualization of thyroid arteries on CT angiography images enables the anatomy of the arterial supply system of the thyroid gland to be explored in a noninvasive manner prior to surgery.

Radiological management of the exiting points of supraorbital region neurovascular bundles / Manejo radiológico de los puntos de salida de los haces neurovasculares de la región supraorbitaria

SUMMARY: A preoperative computed tomography scan is useful to determine neurovascular exit points from orbit to supraorbital region. Determining the structure of exiting points (absence or presence, if present, being in form of foramen or notch) is important to plan the surgical approach. The aim of the study was to provide the radiological data by multi-detector computed tomography for estimating exiting points of the neurovascular bundles of the supraorbital region whether through foramen or notch in living subjects related to side (right/left), sex and age. Computed tomography examinations of 214 (102 male and 112 female) adult patients, aged average 44.2 ± 14 years, were evaluated, retrospectively. Presence or absence, number and nature (foramen/notch) of exiting points of neurovascular bundles were noted in each side regarding sex and age groups. The distance of foramen/notch to the midline of the face was recorded. Single notch was seen on the right in 123 and in 134 on the left, single foramen was seen in 62 on the right and in 56 on the left side and double foramen was seen in 13 on the right and in 6 on the left. The absence was seen in 16 on the right and 18 on the left side. No significant difference was seen on frequency compared between the sexes and age groups. Foramen was seen in 58 sides unilaterally and in 39 sides bilaterally. Notch was unilateral in 75 sides and bilateral in 95 sides. It was shown that males had a wider distance between right side foramen and left side notch to midline. Age groups did not show a significant difference in terms of side. Absence and foramen presence made up about 30-40 % of cases. Notch was the most common form. Foramen/notch presence was statistically unaffected by the sex and age factors. In terms of surgery, preoperative assessment of orbital exit points with computed tomography is essential.

RESUMEN: Una tomografía computarizada preoperatoria es útil para determinar los puntos de salida neurovascular en la región supraorbitaria. Para la planificación del abordaje quirúrgico es importante determinar la estructura de los puntos de salida (ausencia o presencia en forma de foramen). El objetivo de este estudio fue proporcionar los datos radiológicos mediante tomografía computarizada de detectores múltiples, para estimar los puntos de salida de los haces neurovasculares de la región supraorbitaria, ya sea a través del foramen o incisura en sujetos vivos relacionados con lado (derecho/izquierdo), sexo y edad. Se evaluaron retrospectivamente los exámenes de tomografía computarizada de 214 adultos (102 hombres y 112 mujeres), edad 44,2 ± 14 años. Se observó, en cada lado, presencia o ausencia, número y naturaleza (foramen / incisura) de los puntos de salida de los haces neurovasculares en cuanto a sexo y grupos de edad. Se registró la distancia del foramen / incisura al plano mediano de la cara. Se observó un foramen a la derecha en 123 de las tomografìas y en 134 a la izquierda, se observó un foramen simple en 62 a la derecha y en 56 en el lado izquierdo y se visualizó forámenes doble en 13 tomografías a la derecha y en 6 a la izquierda. Se observó ausencia en 16 casos a la derecha y 18 casos a la izquierda. No existió diferencia significativa en la frecuencia comparada entre los sexos y los grupos etarios. El foramen se detectó en 58 lados unilateralmente y en 39 lados bilateralmente. Se demostró que los hombres tenían una distancia mayor entre el foramen del lado derecho y el foramen del lado izquierdo hasta el pno mediano. No se observó una diferencia significativa en los diferentes grupos etarios en términos de lado. La ausencia y la presencia de los forámenes constituían alrededor del 30-40 % de los casos. Los factores de sexo y edad no afectaron estadísticamente la presencia del foramen / incisura. En términos de cirugía, la evaluación preoperatoria de los puntos de salida orbitales con tomografía computarizada es esencial.

Stent-Assisted Coil Embolization of Posttraumatic Dissecting Carotid Aneurysm Causing Ophthalmoplegia.

BACKGROUND: Ophthalmoplegia secondary to a traumatic dissecting aneurysm in the cavernous segment of internal carotid artery (ICA) is a relatively rare entity. Anticoagulant or antiplatelet therapy is the preferred treatment option for carotid dissections. However, endovascular interventions are noninvasive and alternative methods to surgery, especially in cases of aneurysms that do not respond to medical therapy. CASE REPORT: We report of a 19-year-old man presenting with left-sided, total ophthalmoplegia after a traffic accident. Magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) revealed a dissection beginning at the cervical segment of internal carotid artery (ICA) together with a dissecting aneurysm in the cavernous segment. A stent was placed in the narrowed and dissected segment of ICA, and the dissecting aneurysm of the cavernous segment was successfully managed with a stent-assisted coil embolization. After the endovascular treatment of the aneurysm, a full recovery of cranial nerve function was achieved. CONCLUSIONS: Immediate diagnosis and appropriate therapy of dissecting aneurysms is necessary for good clinical outcomes in cases of ophthalmoplegia.

Bilateral thalamic lesions: A pictorial review.

Bithalamic lesions are uncommon, however, both focal and systemic disorders may present bilateral abnormalities in the thalamus in different acute and chronic clinical situations. Neuroimaging, in particular magnetic resonance imaging, plays an essential role in diagnostic approach. Imaging features such as signal alterations, diffusion restriction or contrast enhancement are helpful in characterization of these abnormalities. The location of the lesions may provide key information because some pathologies typically involve a certain part of the thalamus. In addition to thalamic findings, neuroimaging findings in other parts of the brain associated with the clinical and laboratory information should be taken into account to make a correct diagnosis.

Hydatid Cyst of Parotid Gland: An Unusual Case Diagnosed by Fine Needle Aspiration Biopsy.

Hydatid disease is a zoonotic disease caused by the parasite Echinococcus granulosus. This infection frequently infects the liver and the lung and even in endemic regions rarely occurs in the head and neck region. This is also true for the parotid gland. The diagnosis relies on imaging techniques and the medical history. Another method that is helpful in the diagnosis is serological tests. Fine-needle aspiration biopsy is usually not recommended due to the potential risk of anaphylactic shock or spreading of daughter cysts. The preferred treatment method of hydatid cysts in the salivary gland is surgical excision. We introduce a rare case of hydatid cyst in the parotid gland diagnosed preoperatively by fine-needle aspiration biopsy and discuss the differential diagnosis.

Bilateral recurrent external obturator muscle hematoma: An unusual cause of pelvic pain in hemophilia.

Following joint hemorrhages, intramuscular hemorrhages are the second most prevalent bleeding pattern in hemophiliac patients. Hematomas of the iliopsoas muscle are a well-known complication of hemophilia; however, obturator muscle hematomas are rare. We herein report a case of spontaneous bleeding of the bilateral external obturator muscles, which occured three times within a period of 9 months in a hemophilia patient with factor VIII inhibitors. To the best of our knowledge, this is the first published case of an obturator externus muscle hematoma in hemophilia. In addition to hip hemarthrosis, iliopsoas hematomas and acute appendicitis, obturator muscle hematoma should be considered as one of the diagnostic alternatives for pelvic pain in hemophiliaψ patients. Magnetic resonance imaging enables rapid diagnosis of obturator muscle hematoma.

Sinonasal inflammatory myofibroblastic pseudotumor (plasma cell granuloma).

Inflammatory myofibroblastic pseudotumor (plasma cell granuloma) is a soft tissue lesion consisting of myofibroblasts, mature lymphocytes, histiocytes, plasma cells, eosinophils, and extracellular collagen. Various sites in the body may harbor these lesions. Lungs, omentum, intestines, mesentery, and urinary system are the most susceptible areas. It is usually seen in children and young adults. The lesion is rarely detected in the head and neck region. The orbit and the upper respiratory system are the most common localizations in the head and neck region. Sinonasal tract is a rare site of involvement. The differential diagnosis includes squamous cell carcinoma (spindle cell variant), inflammatory fibrosarcoma, leiomyosarcoma, schwannoma, and nonspecific inflammation. Our patient who had a sinonasal mass showed a benign tumor consisting of spindle tumor cells and inflammatory cells histopathologically. This case was presented due to its rare existence to this site.

Diabetic striatopathy in a patient with hemiballism.

Diabetic striatopathy is a rare and life-threatening manifestation of diabetes mellitus. The disease commonly affects individuals of Asian descent, females, and the elderly. Patients usually present with hemiballism-hemichorea caused by nonketotic hyperglycemia. Hemiballism-hemichorea is defined as involuntary continuous random appearing movement involving one side of the body. This movement disorder may develop secondary to stroke, diabetic striatopathy, neoplasm, infection, Wilson's disease, and thyrotoxicosis. Despite being rare, prompt recognition of a hyperglycemia-induced hemiballism-hemichorea is essential because the symptoms are reversible with correction of hyperglycemia. Diagnosis is possible based on blood analysis and neuroimaging findings. Laboratory tests reveal raised blood glucose and hemoglobin A1C levels which indicate poorly controlled diabetes. Neuroimaging provides suggestive findings of diabetic striatopathy which are hyperattenuation on computed tomography and hyperintensity on T1-weighted magnetic resonance imaging in the basal ganglia. In this case report, our aim is to present neuroimaging findings in an adult man with sudden onset of hemiballism associated with nonketotic hyperglycemia.

The diagnostic value of diffusion-weighted imaging and the apparent diffusion coefficient values in the differentiation of benign and malignant breast lesions.

INTRODUCTION: The goal of our study was to evaluate the diagnostic efficacy of diffusion-weighted imaging (DWI) in the differentiation of benign and malignant breast lesions. METHODS: Between June 2012 and March 2013, 60 patients with 63 lesions (age range 29-70 years, mean age 48.6 years) were included in our study. All lesions, except complicated cysts and intra-mammary lymph nodes, were confirmed histopathologically. The patients were evaluated with a 1.5 Tesla MR scanner using dedicated bilateral breast coil. DWI images were obtained by echo planar imaging sequence and 'b' values were selected as 200, 600 and 1000 s/mm(2). Apparent diffusion coefficient (ADC) values of both breast lesions and the normal fibroglandular tissue of the contralateral breast were calculated and statistically compared using Shapiro-Wilk test, Student's t-test, Mann-Whitney U test, chi-square test and the receiver operating curve. RESULTS: Of 63 lesions, 22 were malignant and 41 were benign. In malignant lesions, the mean ADC values were 1.40 ± 0.41 × 10(-3) mm(2)/s for b = 200, 1.05 ± 0.28 × 10(-3) mm(2)/s for b = 600 and 0.91 ± 0.20 × 10(-3) mm(2)/s for b = 1000 and in benign lesions, the mean ADC values were 2.13 ± 0.85 × 10(-3) mm(2)/s for b = 200, 1.64 ± 0.47 × 10(-3) mm(2)/s for b = 600 and 1.40 ± 0.43 × 10(-3) mm(2)/s for b = 1000. The success of ADC values in differentiation of benign and malignant lesions was statistically significant (P = 0.0001). The threshold values were determined to be 1.50 × 10(-3) mm(2)/s for b = 200, 1.22 × 10(-3) mm(2)/s for b = 600 and 0.98 × 10(-3) mm(2)/s for b = 1000 (P < 0.05). CONCLUSION: DWI can be an effective radiological method in the differentiation of benign and malignant breast lesions.

Nonodontogenic mandibular lesions: differentiation based on CT attenuation.

Mandibular lesions are classified as odontogenic and nonodontogenic based on the cell of origin. Odontogenic lesions are frequently encountered at head and neck imaging. However, several nonodontogenic pathologies may also involve mandible and present further diagnostic dilemma. Awareness of the imaging features of nonodontogenic lesions is crucial in order to guide clinicians in proper patient management. Computed tomography (CT) may provide key information to narrow diagnostic considerations. Nonodontogenic mandibular lesions may have lytic, sclerotic, ground-glass, or mixed lytic and sclerotic appearances on CT. In this article, our aim is to present various nonodontogenic lesions of the mandible by categorizing them according to their attenuations on CT.

Abdominal nonparenchymatous cystic lesions and their mimics in children.

Abdominal cystic lesions in children may originate from parenchymatous organs or from nonparencyhmatous structures. Although these lesions have well-described imaging features, proper diagnosis usually depends on the accurate determination of the origin of the lesion. Because large lesions may resemble each other it is difficult to identify the site of origin, which results in a diagnostic dilemma. In this pictorial essay we describe abdominal nonparenchymatous cystic lesions and their mimics arising from parenchymatous organs in children.

Happle-Tinschert syndrome: report of a case with hemimegalencephaly.

Happle-Tinschert syndrome is a disorder causing unilateral segmentally arranged basaloid follicular hamartomas of the skin associated with ipsilateral osseous, dental and cerebral abnormalities including tumors. Although a case with hemimegalencephaly was previously described, this is the first report of Happle-Tinschert syndrome with discrepant short left leg, ipsilateral skin lesions, hemimegalencephaly and frontal polymicrogyria.

An uncommon case of neurofibromatosis type 2: a tribute to the intracranial calcifications.

Neurofibromatosis Type 2 (NF2) is a genetic disorder associated with schwannomas, meningiomas, and ependymomas. Intracranial calcifications, either tumoral or non-tumoral, are relatively lesser known features of NF2. Here, we present a case of NF2, in which the diagnosis was suspected due to the presence of choroid plexus and subependymal calcifications, although no obvious schwannoma or meningioma was detected initially on standard computed tomography or magnetic resonance imaging. This case highlights the importance of further evaluation with appropriate imaging techniques.