Tumor or not a tumor: Pitfalls and differential diagnosis in neuro-oncology.

The majority of intracranial expansive lesions are tumors. However, a wide range of lesions can mimic neoplastic pathology. Differentiating pseudotumoral lesions from brain tumors is crucial to patient management. This article describes the most common intracranial pseudotumors, with a focus on the imaging features that serve as clues to detect pseudotumors.

Direct admission of stroke in MRI room reduces in-hospital delays and improves recovery.

PURPOSE: Efficacy of intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) is strongly time dependent in acute stroke management. We investigated the impact of a direct magnetic resonance imaging (MRI) room admission protocol in order to reduce in-hospital delays. METHODS: We implemented a protocol of direct MRI room admission, bypassing the Emergency Department. We compared in-hospital delays, clinical and functional outcomes using National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores, between patients hospitalized via this protocol and those admitted via the standard workflow and treated by IVT and/or MT. The primary endpoint was the proportion of patients with door-to-needle time (DTN) ≤ 60minutes. RESULTS: Among 308 consecutive patients included, 62 underwent direct MRI room admission. The proportion of patients with DTN ≤ 60minutes was higher in the intervention group compared to the control group (82.5% vs. 17.8%, P<0.001), and median DTN was lower (45min vs. 75min, P<0.001). Despite a functional benefit at discharge on dichotomized mRS (mRS [0-2, as independence]: 66.1% vs. 51.2%, P=0.003), the difference was no longer statistically significant at six months (68.4% vs. 57.4%, P=0.10). CONCLUSION: Direct MRI room admission of stroke alerts is associated with an important reduction of treatment times and improves functional outcomes.

Advanced multiparametric magnetic resonance imaging of multinodular and vacuolating neuronal tumor.

BACKGROUND AND PURPOSE: Multinodular and vacuolating neuronal tumor (MVNT) of the cerebrum is a rare brain lesion with suggestive imaging features. The aim of our study was to report the largest series of MVNTs so far and to evaluate the utility of advanced multiparametric magnetic resonance (MR) techniques. METHODS: This multicenter retrospective study was approved by our institutional research ethics board. From July 2014 to May 2019, two radiologists read in consensus the MR examinations of patients presenting with a lesion suggestive of an MVNT. They analyzed the lesions' MR characteristics on structural images and advanced multiparametric MR imaging. RESULTS: A total of 64 patients (29 women and 35 men, mean age 44.2 ± 15.1 years) from 25 centers were included. Lesions were all hyperintense on fluid-attenuated inversion recovery and T2-weighted imaging without post-contrast enhancement. The median relative apparent diffusion coefficient on diffusion-weighted imaging was 1.13 [interquartile range (IQR), 0.2]. Perfusion-weighted imaging showed no increase in perfusion, with a relative cerebral blood volume of 1.02 (IQR, 0.05) and a relative cerebral blood flow of 1.01 (IQR, 0.08). MR spectroscopy showed no abnormal peaks. Median follow-up was 2 (IQR, 1.2) years, without any changes in size. CONCLUSIONS: A comprehensive characterization protocol including advanced multiparametric magnetic resonance imaging sequences showed no imaging patterns suggestive of malignancy in MVNTs. It might be useful to better characterize MVNTs.

Neurological imaging of brain damages after radiotherapy and/or chimiotherapy.

Radiotherapy and chemotherapy may induce neurological toxicities with different appearances on CT and MRI scans. While optimized radiotherapy techniques have reduced some complications, new unwanted effects have occurred on account of therapeutic protocols involving the simultaneous use of radiotherapy and chemotherapy. Advances in radio-surgery, innovative anti-angiogenic therapies, as well as prolonged patient survival have led to the emergence of new deleterious side effects. In this report, we describe the early, semi-delayed, and late encephalic complications, while specifying how to identify the morphological lesions depending on the therapeutic protocol.

Validity of cervical auscultation in the screening for aspiration.

INTRODUCTION: Cervical auscultation could improve the performance of bedside swallowing test to predict aspiration, especially silent aspiration. The aim of this study is to compare the predictive values of bedside swallowing test performed with and without cervical auscultation by logopedist students who had intensive training on cervical auscultation. MATERIALS AND METHODS: 64 patients were included in the study. They all underwent swallowing test alone, combined swallowing test and cervical auscultation, and videofluoroscopic swallowing study as defined gold standard. Two logopedist students, at the end of their training, performed the auscultation and noted their results. RESULTS: 128 tests were performed, 96% of the tests were judged positive for aspiration. When comparing the results of the two different clinical tests, the detection of clinical signs is not improved by the addition of auscultation. Using a penetration aspiration scale threshold >5, the area under the curve measured for the swallowing test alone was significantly higher than that measured for the combined tests (p = 0.03) (0.66 for the swallowing test alone (95% CI between 0.49 and 0.83), and 0.50 for the combined tests (95% CI between 0.31 and 0.69). CONCLUSION: This study showed no advantage in performing cervical auscultation with bedside swallowing test. Cervical auscultation seems to hamper the assessment, mainly the perception of wet voice and laryngeal motion. These results are compatible with literature but need further confirmation using studies performed with trained logopedists.

Evaluation of dual-source parallel RF excitation technology in MRI of thoraco-lumbar spine at 3.0 T.

High-field 3 T magnetic resonance imaging (MRI) has entered standard clinical practice over the past decade, and its advantages have already been suggested in areas such as neural, musculoskeletal, pelvic and angiographic imaging. However, high-field systems still pose challenges in terms of their specific absorption rate (SAR) and radiofrequency (RF) excitation uniformity. Thus, the aim of the present study was to evaluate the impact, on both these factors, of standard quadrature against parallel RF transmission technology (dual-source parallel RF excitation [DSPE]) in spinal examination at 3 T. The thoracolumbar spine was examined with three different sequences: T1-weighted (T1w); T2-weighted (T2w); and T2w short tau inversion recovery (STIR). Each was acquired with and without DSPE. The manufacturer's implementation of this technology has been associated with optimized handling of patient SAR exposure, resulting in a 38.4% reduction in acquisition time. On comparing sequences with equal repetition times (TRs), the acquisition time reduction was 44.4%. Thus, DSPE allows a reduction in acquisition time. This gain is accompanied by augmentation of the whole-body SAR and diminution of the local SAR. Image quality improvement due to more homogeneous effective transmit B1 was mainly observed at the junction of the thoracolumbar spine.

Prognostic value of perfusion MR imaging in patients with oligodendroglioma: A survival study.

OBJECTIVE: The purpose of this study was to evaluate retrospectively whether cerebral blood volume measurement based on pretreatment perfusion MRI is a prognostic biomarker for survival in patients with oligodendroglioma or mixed oligoastrocytoma. PATIENTS AND METHODS: Between 1998 and 2004, 54 patients (23 females and 31 males), aged 21-73 years, with oligodendroglioma (or mixed tumour) were examined prior to beginning treatment with dynamic susceptibility-weighted contrast (DSC) perfusion MRI during gadolinium first-pass. The relative cerebral blood volume (rCBV) was calculated by dividing the measurement within the tumour by the measurement of the normal-appearing contralateral region. Patients were classified in two groups, grade A and grade B, according to the Saint-Anne Hospital classification and followed-up clinically and by means of MRI until their death or for a minimum of 5 years. Patients were also classified in grade II and grade III-IV, according to the World Health Organisation (WHO) classification, and were analysed with the same methods. Age, sex, treatment, tumour grade, contrast agent uptake, and rCBV were tested using survival curves with Kaplan-Meier's method, and their differences were analysed using the log-rank test. RESULTS: In this population, median survival was 3 years. A rCBV threshold value of 2.2 was validated as a prognostic factor, for survival in these patients with oligodendrogliomas. Age, sex, contrast uptake, and maximum rCBV were found to be prognostic factors in univariate analysis. Multivariate analysis revealed that tumour grade (grade A/grade B), rCBV, age, and sex were prognostic factors independent of the other factors. The tumour grade according to the WHO classification (II versus III-IV) was also detected as an independent prognostic factor. CONCLUSION: Pretreatment rCBV measured by DSC perfusion MRI was found to be a prognostic factor for survival in patients with oligodendroglioma or mixed tumour, by using the Saint-Anne Hospital classification, which separate the IIB from the IIA.

Perfusion MR imaging and 1H spectroscopy: their role in the diagnosis of microcystic and lipomatous meningiomas.

Microcystic and lipomatous meningiomas represent two of the recognised rare subtypes of meningiomas. We describe the CT and MR findings in one adult case of each subtype with emphasis on the diagnostic benefits of perfusion-weighted MR imaging (PWI) and/or proton magnetic resonance spectroscopy (MRS).

Dynamic susceptibility contrast-enhanced MRI evaluation of cerebral intraventricular tumors: preliminary results.

INTRODUCTION: The aims of the present study were to determine the perfusion characteristics of several types of intraventricular tumors and to evaluate the usefulness of dynamic contrast-enhanced MRI in making the differential diagnosis. METHODS: A total of 28 patients with intraventricular tumors (five meningiomas, five papillomas, three ependymomas, four subependymomas, seven central neurocytomas, two subependymal giant cell astrocytomas and two metastases) underwent conventional and dynamic susceptibility contrast-enhanced MRI. Cerebral blood volume (CBV) maps were obtained and the relative CBV (rCBV) calculated for each tumor. Mean rCBV(max) values were compared across the different types of tumors (ANOVA, P=0.05). RESULTS: Intraventricular tumors presented with three different patterns of vascularization: highly vascularized tumors (mean rCBV(max)>3), including papillomas, meningiomas and renal carcinoma metastases; poorly vascularized tumors (mean rCBV(max)<2), including ependymomas and subependymomas; and intermediately vascularized tumors (mean rCBV(max)>2 but<3), including central neurocytomas and lung metastases. There was a significant difference between the highly vascularized (papillomas, meningiomas) and poorly vascularized (subependymomas) tumors. In cases of suspected meningioma, papilloma or neurocytoma, low rCBV values (<3) point to a diagnosis of neurocytoma rather than either of the other tumor types. CONCLUSION: Susceptibility contrast-enhanced MRI can provide additional information on the vascularization of intraventricular cerebral tumors and may help in making the differential diagnosis.

[Value of perfusion MRI in the study of pilocytic astrocytoma and hemangioblastoma: preliminary findings]. / Intérêt de l'imagerie de perfusion dans l'étude des astrocytomes pilocytiques et des hémangioblastomes : étude préliminaire.

PURPOSE: Pilocytic astrocytomas (PA) and hemangioblastomas (HB) can present the same morphological characteristics on conventional MRI sequences, most usually in the form of a cerebellar cystic mass with a mural nodule that strongly enhances on post-contrast T1 images. We discuss here the value of perfusion MRI in the differentiation of these two tumors, the diagnoses of which have already been histopathologically established. METHOD: Eleven patients with PA and eight with HB underwent first-pass perfusion MRI. The maximum relative cerebral blood volume (rCBV(max)), defined as the ratio between the CBV(max) in tumor tissue and the CBV in healthy, contralateral white matter, is considered to be indicative of the type of tumor. RESULTS: The difference between the rCBV(max) of PA (rCBV(max)=1.19+/-0.71, range 0.6-3.27) compared with that of HB (rCBV(max)=9.37+/-2.37, range 5.38-13) was significant (P<0.001). The first-pass curve crossed the baseline, corresponding to vascular permeability problems in both PA and HB. CONCLUSION: The first-pass method of perfusion MRI is a quick and useful way to differentiate between PA and HB.

[Validation of a self assessment for speech disorders (Phonation Handicap Index)]. / Validation d'un questionnaire d'auto-evaluation de la parole (Parole Handicap Index).

OBJECTIVE: The aim of this work is the psychometric validation of a self assessment questionnaire about speech in dysarthria. MATERIALS AND METHODS: A prospective study was performed on 91 persons to analyze reliability and validity of this new questionnaire. It is composed of 25 items subdivided in 3 domains: Physical, functional and emotional. We first compared 17 normal speakers to 21 dysarthric patients. Then we analysed the intra-individual variability with 53 patients who completed the questionnaire twice with two weeks interval between the completion. The statistical analysis verified internal consistency of each item, intra-subject reliability was analyzed through Pearson test and clinical validity was calculated through the non parametric Mann Whitney test. RESULTS: The internal consistency reliability was correct (Cronbach's alpha > 0.9). It appeared a statically significant difference between normal speakers and dysarthric patients (p < 0.05). The correlations to the handicap and severity felt were fair ensured us of the content's validity. However the absence of difference for 5 items drove us to eliminate them. Also, analysis the test / retest by the correlation matrix allowed to delete 5 other questions. The obtained total score was 0,861. As for the validity of contents, the correlations in the handicap and in the degree of severity felt by the dysarthric patients were satisfactory. CONCLUSION: The results of this study allows to resume the validation of this questionnaire, its short form of 15 items is particularly adapted to dysarthric patients. It now remains to test its reliability with the medical evolution of the patients. We propose to name it "Phonation Handicap Index".

[Study of the predictive value of detection tests for silent aspirations]. / Etude de la valeur prédictive des tests de détection des fausses routes silencieuses.

UNLABELLED: Screening for aspiration in patients with swallowing disorders is important in preventing complications. The tests used in this regard are insufficient due to silent aspiration relating to abnormal protective reflexes in many patients with swallowing problems. OBJECTIVE: The aim of this study is to determine the predictive values of simple tests in screening for silent aspiration. MATERIAL AND METHOD: The reference test used was videofluoroscopic examination on swallowing. In the presence of aspiration (FR+) the presence (ME+) or not (ME-) of a cough of throat clearing was noted. The tests being studied were a nasal test with isotonic saline and swallowing according to a set time. RESULTS: For screening for aspiration the presence of a "wet voice" was considered to be a sign of reduced protective reflexes. 1) During the nasal test, the results are 100% for the positive predictive value (VPp) and 83.3% for the negative predictive value (VPn); 2) These results are respectively 84.6% and 35.9% during the swallowing test. Regarding screening for silent aspiration, 1) during the nasal test, the results are 62.5% for the positive predictive value (VPp) and 36.3% for the negative predictive value (VPn); 2) These results are respectively 54.5% and 26.6% during the swallowing test. CONCLUSION: This preliminary study points out the lack of predictive value of the nasal test and the swallow test for the silent aspirations. However the results could be useful for other researchers developing other tests in this area.

[Positioning in the oropharyngeal dysphagia]. / Positionnement dans les dysphagies oropharyngées.

Sitting body posture and the movements for the feeding gesture are interdependent and can worsen an oropharyngeal dysphagia. Their management will have a direct impact on the patient's handicap and will be able to decrease the complications. Clinical process aiming at placing a person having postural disorders, positioning will ensure a base adapted to the person, comfortable, allowing mobility and independence. It requires a methodical accompaniment: evaluation, test, validation, control of adapted equipment for the patient and gesture readjustment.

Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance.

Multinodular and vacuolating neuronal tumor of the cerebrum is a rare supratentorial brain tumor described for the first time in 2013. Here, we report 11 cases of infratentorial lesions showing similar striking imaging features consisting of a cluster of low T1-weighted imaging and high T2-FLAIR signal intensity nodules, which we referred to as multinodular and vacuolating posterior fossa lesions of unknown significance. No relationship was found between the location of the lesion and clinical symptoms. A T2-FLAIR hypointense central dot sign was present in images of 9/11 (82%) patients. Cortical involvement was present in 2/11 (18%) of patients. Only 1 nodule of 1 multinodular and vacuolating posterior fossa lesion of unknown significance showed enhancement on postcontrast T1WI. DWI, SWI, MRS, and PWI showed no malignant pattern. Lesions did not change in size or signal during a median follow-up of 3 years, suggesting that multinodular and vacuolating posterior fossa lesions of unknown significance are benign malformative lesions that do not require surgical intervention or removal.

[Temporal disconnection as an alternative treatment for intractable temporal lobe epilepsy: techniques, complications and results]. / Déconnexion du lobe temporal dans les épilepsies temporales pharmacorésistantes: techniques, complications et résultats.

Temporal lobe epilepsy (TLE) is the most common form of intractable partial epilepsy in adults. Surgery (lobectomy or amygdalohippocampectomy) is effective in most patients. However, some complications can occur and brain shift, hematoma into the post operative cavity and occulomotor nerve palsy have been reported due to the surgical technic. We report the technique, safety and efficacy of temporal disconnection in nonlesional TLE. Forty-seven patients (18 males, 29 females; handedness: 12 left, 33 right; aged 35 years+/-10; mean duration of epilepsy: 24+/-10 years) underwent temporal disconnection (20 left, 27 right) guided by neuronavigation. Sixteen patients (35 %) underwent additional presurgical evaluation with SEEG. The outcome was assessed using Engel's classification. At the two-year follow-up, 85 % of the patients were seizure-free (Engel I), 26 (58 %) of whom were Ia. Postoperative persistent morbidity included mild hemiparesis (n=1), mild facial paresis (n=1), quadranopsia (n=23) and hemianopia (n=1). Verbal memory worsened in 13 % of cases when the disconnection was performed in the dominant lobe. MRI follow-up showed two cases of nonsymptomatic thalamic or pallidal limited ischemias, two cases of temporal horn-cystic dilatation, one requiring surgical reintervention without sequelae. There was one case of postoperative phlebitis. In the seizure-free patient group, postoperative EEG showed interictal temporal spikes at three months, one year and two years located in the anterior temporal region. Temporal disconnection is effective, prevents the occurrence of subdural cyst and hematomas in the temporal cavity, prevents the occurrence of oculomotor palsy, and limits the occurrence of quadranopsia. However, comparative studies are required to evaluate temporal disconnection as an alternative to lobectomy in nonlesional TLE.

[MR and CT perfusion imaging of the brain: principles and clinical applications]. / Imagerie de perfusion: principes et applications cliniques.

MR and CT imaging techniques provide both morphological data and functional data. MR and recently CT perfusion have substantially modified the treatment of acute stroke. CT perfusion offers new opportunities to improve the management strategy in vasospasm after subarachnoid hemorrhage. Both are also helpful for the diagnosis of brain tumors and the assessment of treatment effects.

[Perfusion-diffusion 1H spectroscopy: role in the diagnosis and follow-up of supratentorial brain tumours in adults]. / Spectroscopie 1H, perfusion, diffusion: quelle place pour ces techniques lors du diagnostic et du suivi des principales tumeurs cérébrales sus-tentorielles de l'adulte?

INTRODUCTION: In a few years, magnetic resonance imaging (MRI) has evolved from a morphology-based examination to one that encompasses metabolism and function. STATE OF ART: MRI is a well-established tool for the initial evaluation of brain tumors, but conventional MR sequences have some limitations. Conventional MRI is unable to distinguish high-grade glioma from metastasis and abscess, to define precisely the histopathological grade of gliomas, to determine exactly the limits of tumor extension, to characterize meningeal tumors. Differentiation of tumor recurrence from treatment-related changes may be difficult with standard MR imaging because the interpretation is essentially based on volume analysis. PERSPECTIVES: 1H Spectroscopy, diffusion and perfusion imaging become possible with the development of MR imagers and can be routinely performed in clinical settings. They give complementary information about tumor metabolism and vascularity and allow a better analysis of post-treatment modifications. Functional and metabolic explorations should be used to characterize brain tumors.

[Perfusion MR imaging in brain tumors]. / IRM de perfusion des tumeurs cérébrales.

Perfusion MR Imaging is useful for initial diagnosis and follow up of brain tumors. Dynamic susceptibility contrast MR imaging is described. The limitations and advantages of this technique are discussed with respect to quantification and interpretation of results.