Neurologic pathologies of the vertebral spine.

At some institutions, musculoskeletal and general radiologists rather than neuroradiologists are responsible for reading magnetic resonance imaging (MRI) of the spine. However, neurological findings, especially intrathecal ones, can be challenging. Intrathecal neurological findings in the spine can be classified by location (epidural, intradural extramedullary, and intramedullary) or etiology (tumor, infection, inflammatory, congenital). In this paper, we provide a succinct review of the intrathecal neurological findings that can be seen on MRI of the spine, primarily by location and secondarily by etiology, in order that this may serve as a helpful guide for musculoskeletal and general radiologists when encountering intrathecal neurological pathologies.

Imaging findings of the injured in the massive Beirut blast.

PURPOSE: (1) Describe imaging utilization and findings within two weeks of the 2020 Beirut blast according to the mechanism of injury, (2) determine the appropriate imaging modality per organ/system, and (3) describe changes in the workflow of a radiology department to deal with massive crises. MATERIALS AND METHODS: Two hundred sixty patients presented to the largest emergency department in Beirut and underwent imaging within 2 weeks of the blast. In this retrospective study, patients were divided into early (1) and late (2) imaging groups. Patients' demographic, outcome, type and time of imaging studies, body parts imaged, and mechanism and types of injuries were documented. RESULTS: Two hundred five patients in group 1 underwent 502 and 55 patients in group 2 underwent 145 imaging studies. Tertiary blast injuries from direct impact and falling objects were the most common type of injuries followed by secondary (shrapnel) injuries. Both types of injuries affected mostly the head and neck and upper extremities. Plain radiographs were adequate for the extremities and CT for the head and neck. A regularly updated and practiced emergency plan is essential to mobilize staff and equipment and efficiently deliver radiology services during crises. CONCLUSION: Because the powerful Beirut blast occurred at the port located in the periphery of the city, most injuries seen on imaging were of the upper extremities and head and neck caused by the severe blast wind or penetrating shrapnel and resulted from people using their arms to protect their heads and bodies from direct impact and falling objects.

Brain magnetic resonance imaging findings and brain volumetric differences in a large series of benign rolandic epilepsy.

BACKGROUND: Several studies with a small sample size have investigated the relationship between structural and functional changes on MRI and the clinical and natural history of BRE. We aim to assess the frequency of incidental epileptogenic lesions on brain MRI in a large cohort of patients diagnosed with BRE and to assess the difference in volumetric brain measurements in BRE patients compared to healthy controls. METHODS: The case-control study includes 214 typical BRE cases and 197 control children with non-epileptic spells. Brain MRIs were evaluated for abnormalities which were classified into normal and abnormal with or without epileptogenic lesions with categorization of epileptogenic lesions. Brain segmentation was also performed for a smaller group of BRE patients and another healthy control group. Pearson's chi-squared test and two-tailed independent samples t-test were used. RESULTS: In patients with BRE, 7% had an epileptogenic lesion on their MRI. The frequency of epileptogenic lesion in the control group was 10.2% and not significantly different from those with BRE (p= 0.2). Significantly higher intracranial and white matter volumes were found in BRE patients compared to the healthy group while lower gray matter volume was found in BRE patients. Cortical and subcortical regions showed either higher or lower volumes with BRE. Interestingly, altered subcallosal cortex development which has a known association with depression was also found in BRE. CONCLUSIONS: Our findings confirm the absence of any association between specific brain MRI abnormalities and BRE. However, the altered cortical and subcortical development in BRE patients suggests a microstructural-functional correlation.

Rheumatoid Cerebral Vasculitis in a Patient in Remission.

Cerebral vasculitis is a very rare extra-articular complication of rheumatoid arthritis (RA) that is often challenging to diagnose. Elevated titers of rheumatoid factor (RF), anti-cyclic citrullinated peptide antibodies (anti-CCP), and antinuclear antibodies (ANA) have been linked with severe complications. The absence of highly elevated titers of RF, anti-CCP, and ANA can complicate the diagnosis of RA-associated cerebral vasculitis. We report the case of a 59-year-old woman with long-standing arthritis maintained on rituximab and leflunomide who developed sudden headaches and altered level of consciousness. Laboratory work-up revealed normal lymphocyte count and mildly elevated total serum protein and anti-CCP with negative RF and ANA and no evidence for viral or bacterial infections. Cerebrospinal fluid analysis (CSF) showed slightly elevated anti-CCP with normal levels of CXCL-13 and interleukin 6 (IL-6). Brain magnetic resonance imaging (MRI) showed ill-defined lesion of high T2 signal. Using MR angiogram, MR perfusion, and MR spectroscopy, the diagnosis of rheumatoid cerebral vasculitis was confirmed. The patient was treated with intravenous methyl-prednisolone with fast complete improvement. We conclude that adequate immunosuppression in RA might not be able to prevent rare extra-articular manifestations such as rheumatoid cerebral vasculitis.

Critical infections in the head and neck: A pictorial review of acute presentations and complications.

Non-traumatic head and neck emergencies include several disease processes such as infectious, inflammatory, and malignant. Infections are among the most common pathological processes that affect the head and neck, and are particularly important due to their acute, severe, and potentially life-threatening nature. Radiologists need to be well acquainted with these entities because any delay or misdiagnosis can lead to significant morbidity and mortality. Having a general understanding of such diseases is crucial, their prevalence, clinical presentation, common causative pathogens, route of spread, potential complications, and multimodality radiological appearance. Furthermore, understanding the relevant anatomy of the region, including the various fascial planes and spaces, is essential for radiologists for accurate image interpretation and assessment of potential complications. Our aim is to review the most common severe infections affecting the head and neck as well as other rare but potentially life-threatening infections. We will also describe their imaging features while focusing on the anatomy of the regions involved and describing their potential complications and treatment options.

Stroke in Middle Eastern children with cancer: prevalence and risk factors.

OBJECTIVE: To determine the prevalence and to characterize the different types of strokes in children with cancer at the Children's Cancer Center of Lebanon (CCCL), in addition to assess the factors and clinical findings leading to stroke in children. METHODS: We retrospectively reviewed the medical records and brain images (MRIs and CTs) of children admitted to the CCCL and diagnosed with cancer between years 2008 and 2017. Brain images were reviewed for the strokes' onset, size, location, possible origin, its recurrence and type: intracranial hemorrhage (ICH), acute arterial ischemic stroke, and cerebral sinus venous thrombosis (CSVT) with and without venous infarct. Medical charts of the patients were reviewed for age, sex, their type of cancer, the treatment protocol they followed, and abnormal findings on their laboratory studies and neurological exams. RESULTS: Out of the 905 charts reviewed, twenty-seven children with variable types of cancer had strokes, with a prevalence of 2.9%. Their median age at cancer diagnosis was 9.4 (4.8-13.7) years and the median age at stroke onset was 10.6 (6.7-15.5) years. The median time between the cancer diagnosis and the stroke episode was 6 months. CSVT cases were the most common (60%) followed by acute arterial ischemic (22%) and hemorrhagic strokes (18%), with CSVT being the latest to occur. We observed that the different types of strokes were related to some types of cancer. Of the children that had acute arterial ischemic stroke in this cohort, 83% had brain tumors, of the children who had CSVT, 87.5% had leukemia, and of the children who had hemorrhagic stroke, 40% had leukemia. Neurological abnormalities were more prevalent in acute arterial ischemic stroke (80%). Patients with CSVT recovered better than those with other types of strokes. Strokes recurred in 60% of ischemic strokes. L-Asparaginase was significantly associated with CSVT. CONCLUSIONS: The prevalence of strokes was 2.9% in children with cancer. We were able to identify factors related to the types of the stroke that occurred in children including the type and location of the cancer the type of treatment received, and stroke recurrence.

Intrathecal methotrexate induced myelopathy, rare yet serious complication: A case report and review of the literature.

The regular administration of intrathecal chemotherapy has significantly reduced the risk of central nervous system leukemia in patients with acute lymphoblastic leukemia. We report the case of 28-year-old man who developed intrathecal methotrexate induced myelopathy; a rare but serious side effect of intrathecal chemotherapy. In the light of absent effective treatment strategies, description of the case, along with reviewing similar cases published in the literature will help shed a light on the possible pathophysiologic mechanisms behind this injury. To this date, there are no specific clinical, biochemical and imaging signs that would allow timely detection of intrathecal methotrexate induced myelopathy. This in turn is causing delayed treatment of this injury, resulting in significant morbidity and mortality.

Volumetric measures of the paralyzed vocal fold using computerized tomography; its clinical implication.

OBJECTIVE: To report the volumetric measures of the paralyzed vocal fold in patients undergoing injection laryngoplasty. MATERIAL AND METHOD: All the medical records of patients with unilateral vocal fold paralysis who had high resolution computerized tomography scan of the neck and chest prior to injection laryngoplasty between October 2015 and May 2018 were included. Volumetric evaluation of the vocal folds was performed by measuring the vocal fold height using coronal images and the vocal fold length and width using axial images. RESULTS: A total of 21 patients divided into 13 males and 8 females were identified. The mean age was 56.66 ± 20.94 years. The mean volume of the paralyzed vocal fold was significantly smaller than that of the non-paralyzed vocal fold (p < .05). Similarly, the mean length and height of the paralyzed vocal folds were smaller than those of the non-paralyzed vocal folds (p < .05). CONCLUSION: Volumetric measurements of the paralyzed vocal fold in comparison to the normal vocal fold in a group of 21 patients with unilateral vocal fold paralysis shows the presence of significant difference between the normal and affected site, and the presence of large inter-subject variation. Information on the volume difference between the two vocal folds may be used to better estimate the amount that needs to be injected in medialization procedures.

Pituitary incidentalomas in paediatric population: Incidence and characteristics.

OBJECTIVE: To determine the incidence of pituitary incidentalomas in the paediatric population and among its different age subgroups as well as to identify the characteristics of these lesions. Additionally, we aim to give a perspective on the management and follow-up of these patients. DESIGN AND PATIENTS: We retrospectively studied MRI of children aged 18 years or below who underwent MRI with sellar region within their field of view between January 2010 and December 2018. MEASUREMENTS: Pituitary lesions were considered incidental according to the definition by the Endocrine Society. We reported the size, location and signal characteristics of each lesion. Medical charts of the subjects were reviewed for age, sex, the MRI indication and the hormonal assays levels. RESULTS: We identified 40 pituitary lesions of which 31 were incidental lesions. The incidence of pituitary incidentaloma in our cohort was 22 per 1000 patients with female predisposition ( 64.5%) and a mean age of 11 ± 6 years. Rathke's cleft cyst was the most prevalent lesion, accounting for 67.7% followed by cystic pituitary lesions and microadenomas. The most common indications for imaging were growth disturbance (12.9%) followed by headache (9.7%). Abnormal laboratory workup was present in 13% of the subjects. Incidental lesions were more common in the older age groups compared to young children. CONCLUSION: Incidental pituitary lesions in the paediatric population are relatively infrequent and increases with age. Rathke's cleft cyst is the most common incidentally encountered pituitary lesion followed by cystic pituitary lesions and microadenomas.

Bilateral Subdural Haematoma and CPAP Use: A Possible Association.

Obstructive sleep apnoea (OSA) is a common condition usually treated with continuous positive airway pressure (CPAP). No reports have linked it to an acute subdural haematoma. A 54-year-old white man who had hypertension well controlled with an angiotensin II receptor blocker, presented with a 2-week history of occipital headache with no other focal neurological symptoms. The headache began 12 days after he had started using CPAP for OSA. A brain MRI performed 2 weeks later showed bilateral subdural haematomas which were chronic on the left and sub-acute/acute on the right. Since the patient was clinically stable with no focal neurological deficits, he received prednisone for 3 weeks and was followed up with consecutive CT scans demonstrating gradual regression of the haematomas. This is the first report showing that subdural haematomas could be linked to CPAP use. LEARNING POINTS: Primary care physicians, pulmonologists and neurologists should be alert for unexplained headache in a patient on continuous positive airway pressure (CPAP).Subdural haematoma may be a rare reported side effect of CPAP use.Subdural haematoma in a stable patient with no focal neurological deficits can be treated conservatively with close monitoring and follow-up.

Pre- and Post-therapy Assessment of Clinical Outcomes and White Matter Integrity in Autism Spectrum Disorder: Pilot Study.

Objective: This pilot study aims to identify white matter (WM) tract abnormalities in Autism Spectrum Disorders (ASD) toddlers and pre-schoolers by Diffusion Tensor Imaging (DTI), and to correlate imaging findings with clinical improvement after early interventional and Applied Behavior Analysis (ABA) therapies by Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP). Methods: DTI scans were performed on 17 ASD toddlers/pre-schoolers and seven age-matched controls. Nine ASD patients had follow-up MRI 12 months following early intervention and ABA therapy. VB-MAPP was assessed and compared at diagnosis, 6 and 12 months after therapies. Tract-Based Spatial Statistics (TBSS) was used to measure fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial (RD) diffusivity. Results: VB-MAPP scores improved at 6 and 12 months after early intervention and ABA therapy compared to scores at baseline. TBSS analysis showed significant FA decrease and/or RD increase in ASD patients before therapy vs. controls in inferior fronto-occipital fasciculi, uncinate fasciculi, left superior fronto-occipital fasciculus, forceps minor, left superior fronto-occipital fasciculus, right superior longitudinal fasciculus, corona radiate bilaterally, and left external capsule. A significantly FA increase in 21 tracts and ROIs is reported in post- vs. pre-therapy DTI analysis. Conclusion: DTI findings highlighted ASD patient WM abnormalities at diagnosis and confirmed the benefits of 12 months of early intervention and ABA therapy on clinical and neuro imaging outcomes.

Brain Imaging in New Onset Psychiatric Presentations.

We report two cases of patients who presented with psychiatric symptoms and were found to have brain changes on magnetic resonance imaging. In the first case, a 19-year-old man presented with erratic behavior and odd, paranoid ideas. Imaging of the brain revealed a focus of high FLAIR signal involving the left globus pallidus. The second case was a 21-year-old woman who presented with irritability, racing thoughts, and suicidal ideation. Brain imaging revealed nodules of heterotopic grey matter in the right inferior frontal white matter and foci of subcortical heterotopia with thickening of the adjacent cortex. Both patients received psychotropic medications and showed improvement of their symptoms. Integrating neuroimaging in the evaluation of new onset or atypical psychiatric presentations might be of value in specific cases. It is important to develop clear guidelines for the use of imaging modalities in clinical psychiatric practice.

Automatic Thalamus Segmentation on Unenhanced 3D T1 Weighted Images: Comparison of Publicly Available Segmentation Methods in a Pediatric Population.

The anatomical structure of the thalamus renders its segmentation on 3DT1 images harder due to its low tissue contrast, and not well-defined boundaries. We aimed to investigate the differences in the precision of publicly available segmentation techniques on 3DT1 images acquired at 1.5 T and 3 T machines compared to the thalamic manual segmentation in a pediatric population. Sixty-eight subjects were recruited between the ages of one and 18 years. Manual segmentation of the thalamus was done by three junior raters, and then corrected by an experienced rater. Automated segmentation was then performed with FSL Anat, FIRST, FreeSurfer, MRICloud, and volBrain. A mask of the intersections between the manual and automated segmentation was created for each algorithm to measure the degree of similitude (DICE) with the manual segmentation. The DICE score was shown to be highest using volBrain in all subjects (0.873 ± 0.036), as well as in the 1.5 T (0.871 ± 0.037), and the 3 T (0.875 ± 0.036) groups. FSL-Anat and FIRST came in second and third. MRICloud was shown to have the lowest DICE values. When comparing 1.5 T to 3 T groups, no significant differences were observed in all segmentation methods, except for FIRST (p = 0.038). Age was not a significant predictor of DICE in any of the measurements. When using automated segmentation, the best option in both field strengths would be the use of volBrain. This will achieve results closest to the manual segmentation while reducing the amount of time and computing power needed by researchers.

Gadoterate Meglumine Administration in Multiple Sclerosis has no Effect on the Dentate Nucleus and the Globus Pallidus Signal Intensities.

RATIONALE AND OBJECTIVES: Previous studies on possible accumulation of gadolinium-based contrast agents (GBCA) in the brain suggest that macrocyclic GBCA are less likely to accumulate than linear GBCA. However, conflicting results have been reported, especially in MS. The aim of this study is to investigate retrospectively the correlation between gadoterate-meglumine (macrocyclic GBCA) use and T1 signal intensity changes (SI) in the dentate nucleus and the GP on unenhanced T1-weighted images in a large cohort of MS patients. MATERIALS AND METHODS: Unenhanced T1-weighted images of 232 MS patients who previously received multiple intravenous administrations of 0.1 mmol/kg of gadoterate-meglumine were reviewed. The change in T1 SI ratios of dentate nucleus/central pons (DN/CP) and globus pallidus/centrum semiovale (GP/CSO) was calculated between the first and last MRIs and correlated with age, number of injections, time interval between MRIs, disease duration, activity, and therapy. RESULTS: DN/CP ratio showed no significant changes whereas the GP/CSO ratio showed a significant decrease (p < 0.0001) between the first and last MRIs. Multivariable analyses of both ratios, controlling for age, disease duration, and time interval between MRIs, showed no significant correlation between the number of gadolinium injections and the differences in DN/CP (standardized beta = -0.018, p = 0.811) or GP/CSO SI ratios (standardized beta = -0.049, p = 0.499). CONCLUSION: Repeated administration of gadoterate-meglumine in MS patients did not result in increased T1 SI in the DN or the GP. The significant decrease of GP/CSO ratio between the first and last MRIs is not due to gadolinium accumulation but rather to varying MR parameters.

Frequency and Stratification of Epileptogenic Lesions in Elderly With New Onset Seizures.

Objective: To evaluate prospectively the frequency of epileptogenic lesions in a consecutive cohort of elderly patients presenting with new onset unprovoked seizures, and who underwent a complete evaluation including dedicated epilepsy protocol MRI. Methods and materials: We included all consecutive patients 60 years or older who participated in a prospective study on new onset epilepsy. The work-up included the acquisition of a dedicated epilepsy protocol MRI and a 3 h video/EEG recording. We evaluated the frequency and types of epileptogenic lesions in the whole cohort and stratified those variables by age, gender, types and number of seizures at presentation. We also correlated the EEG findings with the clinical characteristics and neuroimaging results. Results: Of the 101 patients enrolled in the study and who underwent an epilepsy protocol MRI, an epileptogenic lesion was identified in 67% of cases. The most common etiologies were vascular events, followed by tumoral causes and traumatic brain injuries. Epileptogenic lesions were more likely to be identified in patients who presented with only focal aware and impaired awareness seizures. In addition, patients with tumoral epilepsy were significantly more likely to only experience those seizure types compared to patients with other pathological substrates. Interictal/ictal discharges were detected in the EEG of 21% of patients. Epileptiform discharges were significantly more frequent in patients with an epileptogenic lesion on brain MRI, especially in those with a brain tumor. Conclusions: Our results stress the importance of obtaining a dedicated epilepsy protocol MRI in elderly patients with new onset seizures. An epileptogenic lesion will be identified in approximately two thirds of patients with important implications regarding initiation of treatment. In addition, the data underscore the value of distinguishing the types of seizures experienced at presentation as this will apprise the treating physician on the likelihood of identifying an epileptogenic lesion and on the probable etiologies.

Thalamic volume and dimensions on MRI in the pediatric population: Normative values and correlations: (A cross sectional study).

BACKGROUND: Diagnoses of thalamic atrophy in children are based on experts' judgments. No normative measures exist for aiding objective diagnoses. Our aim was to determine normative two-dimensions(2D) and volume measurements of the thalamus in normally developing children. METHODS: MRI images of 245 patients were retrospectively collected. Only participants with normal brain MRIs were included in this cross-sectional study. Anterior-posterior (AP), transverse (T), and craniocaudal (C) diameters were measured. Volumetric masks of the thalamus were manually drawn, whereas volumetric measurements of the brain were automated. RESULTS: 124 patients were male (50.6%). We tabulated our measurements from birth until 18 years old. No significant differences in the thalamus measurements are found between the two hemispheres nor between sexes. The most remarkable increase in the thalamus volume and AP dimension is noted in the first four years of life, following which the values seem to stabilize. Craniocaudal diameters seem to increase in the first year of life, whereas transverse diameters increase until the age of 14 before plateauing. CONCLUSION: We report normative values of the thalamus in 2D and 3D from birth until 18 years of age. A rapid increase in the thalamic size is noted during the first four years of life followed by stabilization.

Gadolinium effect on thalamus and whole brain tissue segmentation.

PURPOSE: Gadolinium-based contrast agent (GBCA) effect on automated segmentation algorithms of subcortical gray matter (GM) is not fully known. The aim of this study is to determine gadolinium effect on the segmentation of the thalamus and whole brain tissue using different automated segmentation techniques. METHODS: Eighty-four multiple sclerosis (MS) patients underwent an MRI acquisition of two 3DT1-weighted sequences with and without gadolinium injection among which 10 were excluded after image quality check. Manual thalamic segmentation considered as gold standard was performed on unenhanced T1 images. volBrain and FSL-Anat were used to automatically segment the thalamus on both enhanced and unenhanced T1 and the degree of similitude (DICE) values were compared between manual and automatic segmentations. Whole brain tissue segmentation (GM, white matter (WM), and lateral ventricles (LV)) was also performed using SIENAX. A paired samples t test was applied to test the significance of DICE value differences between the thalamic manual and automatic segmentations of both enhanced and unenhanced T1 images. RESULTS: Significant differences (FSL-Anat 1.474% p < 0.001 and volBrain 1.990% p < 0.001) in DICE between thalamic manual and automatic segmentations on both enhanced and unenhanced images were observed. Automatic tissue segmentation showed a mean DICE of 81.5%, with LV having the lowest DICE value (74.2%). When compared to tissue segmentations, automatic thalamic segmentations by FSL-Anat or volBrain demonstrated a higher degree of similitude (FSL-Anat = 91.7% and volBrain = 90.7%). CONCLUSION: Gadolinium has a significant effect on subcortical GM segmentation. Although significant, the observed subtle changes could be considered acceptable when used for region-based analysis in perfusion or diffusion imaging.

Diagnostic value of 3DFLAIR in clinical practice for the detection of infratentorial lesions in multiple sclerosis in regard to dual echo T2 sequences.

BACKGROUND AND PURPOSE: The aim of this prospective study is to investigate and evaluate in clinical practice the diagnostic impact of 3DFLAIR in regards to 2DT2/PD in terms of infratentorial lesions detection in multiple sclerosis (MS). MATERIAL AND METHODS: 164 MS patients from the OFSEP database were reviewed retrospectively. MR examinations were performed on 1.5T or 3T systems from four different centers. Infratentorial lesions were counted and allocated to different regions of the posterior fossa by three raters independently (junior resident, resident with an expertise in neuroradiology, and senior neuro-radiologist) on the 3DFLAIR and 2DT2/PD. Both sequences do not have the same spatial resolution but reflect what is recommended by most of the consensus and done in clinical practice. RESULTS: With an overall number of 528 for Rater-1 and 798 for Rater-2 infratentorial lesions, 3DFLAIR had a significantly higher number of lesions detected than 2DT2/PD (303 for Rater-1 and 370 for Rater-2). The prevalence of trigeminal lesions detected by using 3DFLAIR was also significantly higher than 2DT2/PD. ROC analysis showed 3DFLAIR to be more specific and sensitive than 2DT2/PD. An overall difference between all three Raters has been observed. The more the Rater is experienced the more lesions he detects. CONCLUSION: Along with the radiologist ability to detect lesions based on his level of experience, the OFSEP optimized 3DFLAIR can significantly improve infratentorial lesion detection in MS compared to 2DT2/PD. This is important in MS follow-up that takes into account new lesions number to adapt patients' treatment.

Fibroblastic and myofibroblastic tumors of the head and neck: comprehensive imaging-based review with pathologic correlation.

Fibroblastic and myofibroblastic tumors of the head and neck are a heterogeneous group of disorders characterized by the proliferation of fibroblasts, myofibroblasts, or both. These tumors may be further subclassified on the basis of their behavior as benign, intermediate with malignant potential, or malignant. There are different types of fibroblastic and myofibroblastic tumors that can involve the head and neck including desmoid-type fibromatosis, solitary fibrous tumor, myofibroma/myofibromatosis, nodular fasciitis, nasopharyngeal angiofibroma, fibrosarcoma, dermatofibrosarcoma protuberans, fibromatosis coli, inflammatory myofibroblastic tumor, ossifying fibroma, fibrous histiocytoma, nodular fasciitis, fibromyxoma, hyaline fibromatosis and fibrous hamartoma. Although the imaging characteristics of fibroblastic and myofibroblastic tumors of the head and neck are nonspecific, imaging plays a pivotal role in the noninvasive diagnosis and characterization of these tumors, providing information about the constitution of tumors, their extension and invasion of adjacent structures. Correlation with the clinical history may help limit the differential diagnosis and radiologists should be familiar with the imaging appearance of these tumors to reach an accurate diagnosis.