Abstract: Our purpose was to differentiate glioblastoma from metastasis using a single dynamic MR sequence to assess perfusion and permeability parameters. 24 patients with glioblastoma or cerebral metastasis with peritumoral oedema were recruited and explored with a 3T MR unit. Post processing used DPTools software. Regions of interest were drawn around contrast enhancement to assess relative cerebral blood volume and permeability parameters. Around the contrast enhancement Glioblastoma present high rCBV with modification of the permeability, metastasis present slight modified rCBV without modification of permeability. In conclusion, peritumoral T2 hypersignal exploration associating morphological MR and functional MR parameters can help to differentiate cerebral metastasis from glioblastoma.
Abstract: Purpose
Remote cerebellar haemorrhage is a rare and poorly understood complication of neurosurgery.
Methods and results
Based on four cases and a literature review of the fifteen last years, we try to describe and analyse this complication
Conclusion
Remote cerebellar haemorrhage must be considered in patients with unexplained neurological deterioration after cerebral or spinal surgery. Even if mechanism is still unknown venous origin seems obvious. Therefore neurological examination and emergency neuroradiological imaging are needed for patient management.
Abstract: OBJECTIVE: To determine acute intracranial hydrodynamic changes after subarachnoid hemorrhage (SAH) via phase-contrast MRI (PC-MRI) analysis of the CSF stroke volume in the aqueduct (SVaq) and the foramen magnum (SVfm). METHODS: A prospective PC-MRI study was performed on 34 SAH patients in the acute and late phase. Data on CSF flow and hemorrhage site were analyzed according to acute or chronic hydrocephalus (HC). RESULTS: In the acute phase, CSF analysis was performed for 31 patients, 12 of whom presented HC. All 12 had an abnormal SVaq; those with communicating HC (n = 7) had an elevated SV and those with noncommunicating HC (n = 5) had a nil SV. None of the patients with a normal SVaq (n = 11) developed acute HC. Intraventricular bleeding led to more cases of acute HC (P = .005), which was communicating in 58% of cases. In the chronic phase, CSF analysis was performed for 27 patients, 7 of whom presented HC. None of these 7 patients displayed a depressed SVaq. CONCLUSION: SAH led to changes in cerebrospinal fluid hydrodynamics in the majority of patients. Acute HC was communicating in most cases, even when there was intraventricular bleeding. In the late phase, all chronic HC were communicating and did not display aqueductal stenosis.
Abstract: OBJECTIVE: To determine acute intracranial hydrodynamic changes after subarachnoid hemorrhage (SAH) via phase-contrast MRI (PC-MRI) analysis of the CSF stroke volume in the aqueduct (SVaq) and the foramen magnum (SVfm). METHODS: A prospective PC-MRI study was performed on 34 SAH patients in the acute and late phase. Data on CSF flow and hemorrhage site were analyzed according to acute or chronic hydrocephalus (HC). RESULTS: In the acute phase, CSF analysis was performed for 31 patients, 12 of whom presented HC. All 12 had an abnormal SVaq; those with communicating HC (n = 7) had an elevated SV and those with noncommunicating HC (n = 5) had a nil SV. None of the patients with a normal SVaq (n = 11) developed acute HC. Intraventricular bleeding led to more cases of acute HC (P = .005), which was communicating in 58% of cases. In the chronic phase, CSF analysis was performed for 27 patients, 7 of whom presented HC. None of these 7 patients displayed a depressed SVaq. CONCLUSION: SAH led to changes in cerebrospinal fluid hydrodynamics in the majority of patients. Acute HC was communicating in most cases, even when there was intraventricular bleeding. In the late phase, all chronic HC were communicating and did not display aqueductal stenosis.
Abstract: The diagnosis and management of patients with idiopathic normal-pressure hydrocephalus (NPH) remain somewhat controversial and there is no clear guideline for assessing the post-shunt outcome. The objective of this study was to investigate whether cerebrospinal fluid (CSF) flow dynamics is linked to post-shunt improvement. Fourteen NPH patients (nine males and five females; mean age, 68 years) investigated by magnetic resonance imaging (MRI) before surgical diversion of CSF were retrospectively reviewed. Phase-contrast sequences were added to the morphological clinical protocol for quantification of CSF oscillations, which were recorded at the level of the cerebral aqueduct and the C2 and C3 subarachnoid spaces (SAS). The phase-contrast images were analysed with custom-designed dedicated flow segmentation software. The oscillations measured in this hydrocephalus population were compared to a previously studied healthy population. A difference of at least two standard deviations was used to define a hyperdynamic or hypodynamic state of CSF flow. The cervical CSF flow of the hydrocephalus patients was not significantly different from those of the volunteer population. Of the 14 hydrocephalus patients, 12 had a good response to the shunt. Of these, 10 presented an increased ventricular CSF flow, one a low ventricular CSF flow, and the last one had a normal ventricular CSF flow. Phase-contrast MRI can help develop guidelines for surgical management of NPH. The shunt responders appear to be the patients with hyperdynamic ventricular CSF flow and normal cervical CSF flow.
Abstract: Cognitive impairment is now well documented in patients with multiple sclerosis (MS), and series of MS patients with predominant cognitive problems have been published recently. We report the observation of a female patient with severe cognitive presentation at the onset of MS, with dramatically demented evolution, and show MRI examination results. We discuss the published reports of primary cognitive types of MS.
Abstract: Our aim was to describe the immediate or early complications and technical failures occurring during balloon kyphoplasty (BKP) procedures and attributable to balloon inflation.
Abstract: Purpose: To evaluate the feasibility, efficacy, and safety of percutaneous vertebroplasty (PV) in the treatment of pathologic fractures owing to malignancy with epidural involvement, with or without neurologic symptoms of spinal cord or cauda equina compression. Materials and Methods: This study was approved by the local ethics committee; informed consent was obtained from all patients. This retrospective review was performed for 51 consecutive patients with metastatic disease or multiple myeloma treated by means of vertebroplasty, who presented with at least one vertebral lesion with epidural involvement, with or without clinical symptoms of spinal cord or cauda equina compression. All patients with neurologic deficit were terminally ill. A neurologic examination was performed before and after treatment in all patients. All imaging examinations and treatments were reviewed, and chi(2), Mann Whitney, or Fisher exact testing was performed for univariate analysis of variables. Results: A total of 74 vertebrae were treated in 51 patients, 22 women and 29 men with a mean age of 62.5 years (range, 28-85 years). Fifteen (29%) patients presented symptoms of complete or incomplete spinal cord or cauda equina compression before vertebroplasty and no further clinical deterioration was observed after treatment. The analgesic efficacy of vertebroplasty was satisfactory for 94% (48 of 51) of patients after 1 day, 86% (31 of 36) patients after 1 month, and 92% (11 of 12) patients after 1 year. One patient with no clinical neurologic deficit before treatment experienced symptoms of cauda equina compression 2 days after vertebroplasty. No other major complication was observed. Conclusion: The feasibility, efficacy, and safety of PV were confirmed in patients experiencing pain related to malignant spinal tumors with epidural extension, with a low complication rate. PV should become part of the palliative analgesic treatment for such patients. (c) RSNA, 2010.
Abstract: Visual disturbances (VDs) are reported with an average rate of 1.4% after foam sclerotherapy (FS). Some clinical clues indicate that they could correspond to migraine with aura (MA).
Abstract: To prove the feasibility of arterial spin labeling (ASL) to explore brain tumors by comparing dynamic susceptibility contrast-enhanced MRI to ASL at 3T MR.
Abstract: Although crucial in regulating intracranial hydrodynamics, the cerebral venous system has been rarely studied because of its structural complexity and individual variations. The purpose of our study was to evaluate the organization of cerebral venous system in healthy adults. Phase-contrast magnetic resonance imaging (PC-MRI) was performed in 18 healthy volunteers, in the supine position. Venous, arterial, and cerebrospinal fluid (CSF) flows were calculated. We found heterogeneous individual venous flows and variable side dominance in paired veins and sinuses. In some participants, the accessory epidural drainage preponderated over the habitually dominant jugular outflow. The PC-MRI enabled measurements of venous flows in superior sagittal (SSS), SRS (straight), and TS (transverse) sinuses with excellent detection rates. Pulsatility index for both intracranial (SSS) and cervical (mainly jugular) levels showed a significant increase in pulsatile blood flow in jugular veins as compared with that in SSS. Mean cervical and cerebral arterial blood flows were 714+/-124 and 649+/-178 mL/min, respectively. Cerebrospinal fluid aqueductal and cervical stroke volumes were 41+/-22 and 460+/-149 microL, respectively. Our results emphasize the variability of venous drainage for side dominance and jugular/epidural organization. The pulsatility of venous outflow and the role it plays in the regulation of intracranial pressure require further investigation.
Abstract: Intracranial lipomas are rare congenital malformations which are neither hematomas nor true neoplasms. They result from the abnormal persistence and maldifferentiation of the meninx primitiva. The majority of such lesions occur near the midline. Around 55% of intracranial lipomas are associated with brain malformations of varying severity. Although they are usually an incidental finding, symptomatic intracranial lipomas are sometimes observed. Surgical excision may result in high morbidity and mortality due to the highly vascular nature of intracranial lipomas and the latter's strong adhesion to the surrounding tissue and is very rarely indicated.
Abstract: Anatomical variants of the sinonasal cavities are common. About 15 major variants are described (nasal septal deviation is present in up to 62% of the population). Because the may lead to complications at the time of endovascular procedures or endoscopic sinonasal surgery (vascular, nervous, or osseous injury), there detection has medicolegal implications. Knowledge of anatomical variants by radiologists and ENT surgeons is thus required. We will describe these variants, their imaging features, frequency, implications and associated risk of potential complication.
Abstract: Arterial spin labeling (ASL) perfusion MR imaging is a technique by which water from circulating arterial blood is magnetically labeled and acts as a diffusible tracer allowing non-invasive measurement of cerebral blood flow. In this paper, the technique and current applications in neuroimaging will be reviewed. CURRENT STATUS: First, the technical principles of ASL will be reviewed and both available techniques (continuous and pulsed ASL) explained. A review of the literature will demonstrate advances with the techniques of ASL and its clinical impact. Clinical research involves normal volunteers and patients with ischemic and tumoral pathologies. CONCLUSION: Recent technical advances have improved the sensitivity of ASL perfusion MR imaging. The routine clinical use of ASL at 3.0 Tesla should increase over the next few years.
Abstract: BACKGROUND AND PURPOSE: Glioma and meningioma are the two most common types of primary brain tumor. The aim of the present study was to analyze, using dynamic susceptibility contrast MR perfusion imaging, the effect of angiogenesis on peritumoral tissue. METHODS: In this prospective study, conducted from December 2003 to March 2005, out of 18 patients recruited, 12 were included (six with meningioma, six with glioblastoma). Using rates of maximum signal drop (MSD), we drew regions of interest (ROI) starting near the lesion, and gradually moving outwards to areas of distant edema in axial and sagittal planes at 10, 20 and 30 mm from the tumor. We also drew ROI on the contralateral brain white matter to obtain a normal baseline for comparison (relative MSD; rMSD). RESULTS: In regions of peritumoral T2 hypersignals, we observed a decrease in rMSD with distance from glioblastoma due to reduced angiogenesis, and an increase in rMSD with distance from meningioma, probably due to a reduced mass effect. CONCLUSION: In our study, dynamic susceptibility contrast MR perfusion imaging, using MSD as a parameter, revealed differences between meningioma and glioblastoma peritumoral tissue due to changes in angiogenesis.
Abstract: INTRODUCTION: Bithalamic paramedian infarcts are uncommon. This stroke results in a complex clinical syndrome. CASE REPORT: We report four cases of bithalamic paramedian infarcts with a presumed mechanism of occlusion of a single thalamic paramedian artery. DISCUSSION: This normal anatomic variant corresponds to an asymmetrical common trunk for the two thalamosubthalamic paramedian arteries arising from a P1 segment (type IIb in the G. Percheron classification dating from 1977). A literature analysis (from 1985 to 2006) allowed us to identify the most widely reported clinical signs. Four main clinical findings are described: vertical gaze palsy (65%), memory impairment (58%), confusion (53%) and coma (42%). We also found these symptoms in our patients but rarely associated; however, all four patients had exhibited episodes of drowsiness. In this article, we discuss the anatomy-function correlation responsible for such clinical variability. CONCLUSION: Clinicians should be aware of this diagnosis to better understand the imaging results which provide confirmation. Although the literature describes frequently severe consciousness disorders such as coma, this diagnosis must also be considered in patients presenting a simple fluctuation of consciousness, e.g. hypersomnia.
Abstract: True carotid aneurysms with sphenoid extension and revealed by epistaxis are rare. A review of the literature shows the mortality risk of this pathology and the different therapeutic options. A 41-year-old female presented with a cavernous carotid aneurysm with sphenoid extension revealed by massive epistaxis. We propose a combined treatment of the affected vessel using coils and an uncovered stent. The first stage to stop the hemorrhages and occlude the aneurysm using the coil and the second stage several days later after anticoagulation using the stent to prevent revascularization. This treatment has been shown to be effective in producing immediate hemostasis and stable long-term occlusion.
Abstract: BACKGROUND AND PURPOSE: Patients with aqueductal stenosis (AS) present with various clinical and radiologic features. Conventional MR imaging provides useful information in AS but depends on a subjective evaluation by the neuroradiologist. The purpose of this study was to evaluate the support of the phase-contrast MR imaging (PC-MR imaging) technique (sensitive to CSF flows) for the diagnosis of AS. MATERIALS AND METHODS: We retrospectively considered 17 patients who underwent PC-MR imaging to explore hydrocephalus, with the absence of CSF flow at the aqueductal level. We analyzed their clinical and morphologic MR imaging data. RESULTS: None of the usually reported direct or indirect signs of aqueductal obstruction were seen in 7 patients in whom the clinical suggestion of AS was confirmed by PC-MR imaging results. Seven patients in this population had a third ventriculostomy, and 5 of them were among those in whom conventional MR imaging failed to reveal signs of aqueductal obstruction. All of these 7 patients had a positive postsurgical outcomes. The analysis of CSF and vascular dynamic data in this population was compared with an aged-matched population, and these data were found similar except for the fourth ventricular CSF flush flow latency. CONCLUSIONS: PC-MR imaging supports the diagnosis of CSF flow blockage at the aqueductal level in a reliable, reproducible, and rapid way, which aids in the diagnosis of AS in patients with clinical and/or radiologic suggestion of obstructive hydrocephalus. We, therefore, suggest using this technique in the current evaluation of hydrocephalus.
Abstract: PURPOSE: Determining acute intracranial hydrodynamic changes after subarachnoid hemorrhage through an analysis of the CSF stroke volume (SV) as measured by phase-contrast MRI (PC-MRI) in the mesencephalon aqueduct. METHOD: A prospective study was performed in 33 patients with subarachnoid hemorrhage. A PC-MRI imaging study was performed n the acute phase (< 48 hours). CSF flow was measured in the aqueduct. The appearance of acute hydrocephalus (HCA) was then compared with data on CSF flow, and the location of the intraventricular and perimesencephalic bleeding. RESULTS: CSF analysis was performed on 27 patients, 11 of whom presented with an acute HCA. All 11 patients had an abnormal SV in the aqueduct: patients with a communicating HCA had an increased SV (n=8); and patients with a noncommunicating HCA had a nil SV (n=3). Patients with a normal SV in the aqueduct did not develop an acute HCA. Intraventricular bleeding significantly led to HCA (P=0.02), which was of the communicating type in 70% of cases. CONCLUSION: Subarachnoid hemorrhage leads to intracranial CSF hydrodynamic modifications in the aqueduct in the majority of patients. CSF flow can help us to understand the mechanism of the appearance of acute HCA. Indeed, hydrocephalus occurred - of the communicating type in most cases - even in the presence of intraventricular bleeding.
Abstract: BACKGROUND AND PURPOSE: MR diagnostic of postoperative recurrent cholesteatomas is difficult. Our purpose was to compare multishot fast spin-echo periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted MR imaging (DWI) with array spatial sensitivity encoding technique (ASSET) single-shot echo-planar DWI and late postgadolinium T1-weighted MR imaging for the detection of postoperative recurrent middle ear cholesteatomas with a 3T imaging unit. MATERIALS AND METHODS: Thirty-five patients with suggested postoperative recurrent middle ear cholesteatoma underwent 3T MR imaging with PROPELLER DWI, ASSET echo-planar DWI, and late postgadolinium T1-weighted MR imaging. Three radiologists (2 seniors, 1 fellow) analyzed unlabeled images for visualization of recurrence. Interobserver and intraobserver agreement was assessed by using the Cohen kappa statistic test. Sensitivity, specificity, and predictive value were assessed for the 3 observers. RESULTS: Nineteen recurrent cholesteatomas were diagnosed. PROPELLER interobserver agreement was very good (1, 0.89, 0.89) among the 3 observers. Intraobserver agreement between PROPELLER and T1-weighted imaging was very good to moderate (0.88, 0.57, 0.58). PROPELLER DWI provided less interobserver variability than other sequences, and the best sensitivity, specificity, and predictive value. CONCLUSIONS: On a 3T imaging unit, multishot fast spin-echo PROPELLER DWI allows an easier detection of postoperative recurrent middle ear cholesteatoma than T1-weighted imaging by reducing artifacts and by its better contrast. DWI with PROPELLER is diagnostically robust and accurate.
Abstract: After having provided a brief reminder of the principle of the blood oxygen level-dependent (BOLD) contrast effect, the physiological bases of brain activity and the concepts of functional integration and effective connectivity, we describe the most recent approaches, which permit to explore brain activity and putative networks of interconnected active areas in order to examine the normal brain physiology and its dysfunctions. We present various methods and studies of brain activity analysis clinically applicable, and we detail the concepts of functional and effective connectivity, which allow to study the cerebral plasticity which occurs at the child's during the maturation (e.g., dyslexia), at the adult during the ageing (e.g., Alzheimer disease), or still in schizophrenia or Parkinson disease. The study of specific circuits in networks has to allow defining in a more realistic way the dynamic of the central nervous system, which underlies various cerebral functions, both in physiological and pathological conditions. This connectivity approach should improve the diagnostic and facilitate the development of new therapeutic strategies.
Abstract: Vascular anomalies are a complex pathological group. They are especially difficult to study because of confusion in the terminology used. The classification developed by the ISSVA (International Society for the Study of Vascular Anomalies) now allows using a common scientific language. The classification is based on clinical, radiological, hemodynamic, and histological arguments. There are two groups of lesions: vascular tumors and vascular malformations. Vascular tumors are associated to vascular proliferation. They are called hemangioma and can be infantile or congenital. Vascular malformations are associated to vessels with morphologic anomalies. They are classified according to the distorted vessel type, capillary, venous, lymphatic, and arteriovenous). Such a classification has many implications. It is a guide for the orientation of radiological exams and treatment of vascular anomalies. The management of these anomalies is still difficult and must involve an interdisciplinary approach.
Abstract: Emergency departments frequently encounter pathology resulting from injury to the foot and ankle, with approximately 6000 case per day in France. In an ankle sprain, 85% of the lesions involve the lateral collateral ligament. Many other, much rarer, types of lesion with different therapeutic consequences can present, however. Interpretation of the initial conventional radiographs is vital to establishing the type lesion and to proposing adapted and rapid treatment. The objective of this article is to review the various osteoarticular and ligament injuries encountered in the foot and the ankle.
Abstract: AIM: To validate, through functional magnetic resonance imaging (fMRI) from spectral analysis of time series during a visuomotor task, a model of functional connectivity mainly constituted by the pre-supplementary motor area (pre-SMA), the supplementary motor area proper (SMA-proper) and the primary motor cortex (M1). MATERIALS AND METHODS: The paradigm that was tried out in young subjects (n=5) consisted of a preparation task of motor movement. We firstly proceeded with an estimate in the frequency domain of coherency coefficients and values of phase shift between these three areas. Secondly, the estimated coherency coefficients were integrated to a model of functional connectivity. Two interaction coefficients were calculated, one for the related M1 and pre-SMA regions, the other one for the related M1 and SMA-proper regions. RESULTS AND CONCLUSION: Our results demonstrate hemodynamic activity that definitely occurred earlier in the pre-SMA area during the preparatory period of the task. In the same way, a more important interaction was found between M1 and pre-SMA areas, which corroborates the assumption of the prevalent role played by these two areas in the case of a preparation task of a motor movement. Thus, this study has allowed highlighting a functional dissociation between the two portions of the SMA.
Abstract: AIM: The distal dural ring plane (DDRP) separates the intracavernous from the supracavernous paraclinoid internal carotid artery. The purpose of this MRI protocol is to evaluate the position of this plane for the characterization of paraclinoid aneurysms. METHOD: The protocol uses a T2 weighted sequence in two orthogonal planes (diaphragmatic and carotid planes) and two correlation lines in each plane. These lines pass through anatomo-radiological reference points correlated with the medio-lateral and antero-posterior margins of the DDRP. We use the intersection angle of these lines as the inferior radiological limit of the DDRP curve. RESULTS: An aneurysm located above this angle is supracavernous; an aneurysm located below this angle is intracavernous; an aneurysm crossing this angle is transitional. CONCLUSION: In difficult cases, this MRI protocol could help better characterize the exact localization of paraclinoid aneurysms on both sides of the cavernous sinus roof.
Abstract: Among individuals aged 50-80 years, 5-20% have one or more vertebral crush fractures. One-third of these patients require treatment for acute or chronic pain. Vertebroplasty and kyphoplasty were introduced over the last two decades as treatments for incapacitating pain from osteoporotic vertebral fractures. Both techniques proved effective and safe in numerous retrospective and prospective studies. They now deserve to be incorporated into the standard treatment strategy for painful and incapacitating vertebral fractures. Kyphoplasty seeks not only to stabilize the vertebra, but also to correct the kyphosis induced by the vertebral body collapse. However, the correction is often limited (less than 15 degrees ) and has not been shown to increase the benefits in terms of pain relief or quality-of-life improvement, compared to vertebroplasty. Kyphoplasty is more costly than vertebroplasty, which is therefore emerging as the treatment of choice. However, a randomized double-blind trial comparing vertebroplasty and kyphoplasty is needed. Furthermore, a randomized comparison of vertebroplasty or kyphoplasty versus noninterventional treatment is needed in patients admitted for pain immediately after a vertebral crush fracture.
Abstract: The distal dural ring plane (DDRP) separates the intradural from the extradural paraclinoid internal carotid artery. The purpose of this study was to evaluate its position with MR imaging. The protocol used a T2-weighted sequence in two orthogonal planes: diaphragmatic (DIA-P) and carotid (CAR-P). The DDRP passes through four anatomoradiological reference points (RefP). We developed on a cadaveric model a correlation method supported by correlation lines and angles (CA) projecting the RefP toward the DDRP. RefP were correlated to the DDRP in 65-84% of cases in the DIA-P and 60-76% of cases in the CAR-P. CA were identified and correlated to the DDRP, respectively, in 87% and 60% of cases in the DIA-P, and 60% and 51% of cases in the CAR-P (failure often related to a lack of visibility of just one RefP). A higher tissular contrast in living subjects allowed the identification of CA in 90% and 80% of cases, respectively, in the DIA-P and the CAR-P. We propose that CA, when identified, should be considered as an approximation of the inferior radiological limit of the DDRP curve. In difficult angiographical cases, this MRI protocol could help to locate paraclinoid aneurysms on both sides of the cavernous sinus roof.
Abstract: OBJECTIVES: The purpose of this study was to evaluate the diagnosis criteria, the bacteriology and the evolution after adapted treatment of intracranial abscess of ENT origin. MATERIAL AND METHODS: It was a retrospective study from 1985 to 2003 concerning 22 patients who had brain abscesses secondary to an ENT infection. RESULTS: The infectious origin was sinusoid in 32% of cases, otologic in 32% of cases, pharyngeal or dental in 27% of cases and cutaneous in 9% of cases. The clinical symptoms were: fever in 55% of cases, headache in 73% of cases (Intra cranial hypertension syndrome in 23% of cases), epilepsy in 32% of cases and various other neurologic symptoms. Bacteria were identified in 82% of cases. In 50% of cases multibacterial associations were found. All the patients had bi antibiotherapy associated to surgical excision of the abscess (16 cases) or single (or more) punction (stereotaxic guided or not) of the abscess. 3 patients (14%) died and 50% are alive and well. CONCLUSION: The diagnosis of cerebral abscess is often difficult. The "classical" intracranial hypertension associated to high fever is usually incomplete and sometimes absent. There is no predominant bacteria involved and multibacterial infections are frequent. Despite abscesses are serious and potentially lethal, an early diagnosis, a medical (antibiotics) and surgical treatment (punction and/or surgical excision) may completely be cured in more than 50% of cases.
Abstract: The authors report a case of intraventricular tumor. The tumor was initially misdiagnosed as an oligodendroglioma but later proved to be a central neurocytoma. The imaging and histopathological features are reviewed. The immunopositivity allows a diagnosis of neurocytoma. Prognosis is favorable following total surgical resection, with low recurrence rate.
Abstract: The authors report four cases of aneurysm of the lenticulostriate arteries, three idiopathic and one with underlying MoyaMoya disease. This unusual pathology, which often affects young patients, is revealed by a meningeal syndrome and sometimes focal neurological signs. The bleeding is highlighted by a CT scan without contrast injection, even by MRI, these examinations making it possible to evaluate its repercussion. Arteriography or MRA show the aneurysm and eliminate vascular malformation. According to literature (15 cases published) and our experience, considering the difficulty of a surgical or endovascular approach, morbidity and the frequency of spontaneous thromboses, it seems that a conservative management is justified after a negative etiologic check-up and under radio-clinical monitoring.
Abstract: The perfusion imaging has shown its interest in the diagnosis and therapeutic monitoring of brain tumors. The MRI methods to measure the perfusion can be divided into two groups: methods using intravenous contrast agents and those not using them. The clinical applications on this imaging are still evaluating. After reminders on brain tumors, on angiogenesis and on contrast agent’s properties, we present the basic techniques of magnetic resonance imaging perfusion (MRI), and describe the different sequences acquisitions and analysis methods of perfusion images. In a second part three clinical studies using dynamic susceptibility contrast MR perfusion imaging, permeability and perfusion without injection of contrast are detailed and allow to characterize different types of brain tumors (eg, meningiomas, glioblastomas) These studies demonstrate the clinical use of MRI perfusion for a better diagnosis of encephalic tumors.
Abstract: Middle ear cholesteatoma consist in a squamous keratinized epithelium of the middle ear. The gravity is due to its extensive and osteolytic properties. Its treatment is surgical. It is a disease with a high risk of recurrence. Diagnosis of postoperative recurrent middle ear cholesteatoma is mainly performed on thin-section high-resolution CT. When the middle ear is completely filled, MR Imaging with late postgadolinium T1 weighting has an additional value. Several authors showed interest in using diffusion weighted MRI (DWI) for depicting recurrent cholesteatomas on a 1.5 Tesla Imaging unit. But the diffusion has the problem of low spatial resolution and especially the magnetic susceptibility artifacts at the interfaces air / bone or air / tissue of the ear and mastoid. The purpose of this study is to compare two sequences of diffusion: multishot fast spin echo periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) DWI and single shot ASSET echo-planar DWI for the detection of recurrent cholesteatoma on 3T Imaging unit. 35 patients with suggested postoperative recurrent cholesteatoma underwent 3 T MRI with PROPELLER DWI, ASSET-Echo-planar DWI and late postgadolinium T1 weighted MR imaging. Three radiologists (2 seniors, 1 fellow) analyzed unlabeled images for visualization of recurrence. Intra and interobserver agreement was assessed by using the Cohen Kappa statistic test. Sensitivity, specificity and predictive values were assessed for each observer. A total of 19 recurrent cholesteatomas were diagnosed. PROPELLER interobserver agreement was very good (1, 0.89, 0.89) among the 3 observers. Intraobserver agreement between PROPELLER and T1 weighted Imaging was moderate to very good (0.88, 0.57, 0.58). PROPELLER DWI provided less interobserver variability than other sequences, and the best sensitivity, specificity and predictive value. Conclusions: On a 3T Imaging unit, multishot fast spin-echo PROPELLER DWI allows an easier detection of postoperative recurrent middle ear cholesteatoma than ASSET echo-planar DWI reducing magnetic susceptibility artifacts and by its better contrast. From our findings it would appear that PROPELLER offers High sensitivity, specificity and predictive values. The correlation with more results of pathology might show higher predictive values for PROPELLER than T1 weighted Imaging.
