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.

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.

Fibromuscular dysplasia: what the radiologist should know: a pictorial review.

UNLABELLED: Fibromuscular dysplasia (FMD) is an idiopathic, segmentary, non-inflammatory and non-atherosclerotic disease that can affect all layers of both small- and medium-calibre arteries. The prevalence of FMD is estimated between 4 and 6 % in the renal arteries and between 0.3 and 3 % in the cervico-encephalic arteries. FMD most frequently affects the renal, carotid and vertebral arteries, but it can theoretically affect any artery. Radiologists play an important role in the diagnosis of FMD, and good knowledge of FMD's signs will certainly help reduce the delay between the first symptoms and diagnosis. The common string-of-beads aspect is well known, but less common presentations also have to be considered. These less common imaging findings include vascular loops, fusiform vascular ectasia, arterial dissection, aneurysm and subarachnoid haemorrhage. These radiologic presentations should be known by radiologists in order to diagnose possible FMD, particularly when present in young females or when associated with personal or familial hypertension, to reduce the delay between the onset of the first symptom and the final diagnosis. The patients have to be referred to specialised FMD centres for dedicated management. TEACHING POINTS: • Fibromuscular dysplasia is not a rare disease. • Radiologists should recognise less common presentations to orient specific management. • Vascular loops, fusiform vascular ectasia and a "string-of-beads" aspect are typical presentations. • Arterial dissection, aneurysm and subarachnoid haemorrhage are less typical radiologic presentations.

The different faces of central nervous system metastases.

Cerebral metastases are the commonest central nervous system tumors. The MR assessment should include T1-weighted images with and without enhancement and T2/FLAIR images. They usually appear as multiple lesions with nodular or annular enhancement and are surrounded by edema. They are hypervascularized and have no restriction of their diffusion coefficient in their necrotic area and contain lipids on 1H spectroscopy. Metastases can be distinguished from primary tumors by the lack of malignant cell infiltration around the tumor. Stereotactic radiotherapy may temporarily increase tumor volume, although this is not of adverse oncological value. Less commonly, spinal disease may be asymptomatic and should be examined by MR.

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.

Functional imaging of cerebral perfusion.

The functional imaging of perfusion enables the study of its properties such as the vasoreactivity to circulating gases, the autoregulation and the neurovascular coupling. Downstream from arterial stenosis, this imaging can estimate the vascular reserve and the risk of ischemia in order to adapt the therapeutic strategy. This method reveals the hemodynamic disorders in patients suffering from Alzheimer's disease or with arteriovenous malformations revealed by epilepsy. Functional MRI of the vasoreactivity also helps to better interpret the functional MRI activation in practice and in clinical research.

Perfusion imaging in brain disease.

Perfusion CT or MRI have been extensively developed over the last years and are accessible on most imaging machines. Perfusion CT has taken a major place in the assessment of a stroke. Its role has to be specified for the diagnosis and treatment of the vasospasm, complicating a subarachnoid hemorrhage. Perfusion MRI should be included in the assessment of any brain tumor, both at the time of the diagnosis as well as in the post-treatment monitoring. It is included in the multimodal approach required for the optimum treatment of this disease. The applications in epilepsy and the neurodegenerative diseases are in the evaluation process.

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.

[Cerebral amyloid angiopathy is difficult to diagnose in the intensive care unit]. / Angiopathie amyloïde cérébrale : un diagnostic difficile en réanimation.

Cerebral amyloid angiopathy is a common cause of intracerebral haemorrhage in elderly patients. The diagnosis of cerebral amyloid angiopathy is based on the Boston criteria combining clinical and radiological criteria with no other cause of intracerebral haemorrhage. We describe the case of a 60-year-old female admitted to the intensive care unit for agitation and spatial disorientation. She had multiple intracerebral haematomas on brain CT scan. Typical cerebral microbleeds using MRI and the absence of other cause of intracerebral haemorrhage argued in favour of the diagnosis of cerebral amyloid angiopathy. The patient outcome was favourable with a discharge from the intensive care unit on day 16.

[Whipple's disease: a curable encephalitis]. / La maladie de Whipple : une cause curable d'encéphalite.

INTRODUCTION: Whipple's disease is a rare systemic infectious disorder. It may present with a wide range of clinical manifestations and therefore its diagnosis may be challenging. CASE REPORT: We report a 45-year-old man who presented with acute encephalitis related to Whipple's disease. Despite the negativity of the polymerase chain reaction (PCR) test in cerebrospinal fluid, diagnosis was obtained by histopathology, PCR tests and immunohistochemistry in multiple samples. The outcome with antibiotherapy was considered as "spectacular". CONCLUSION: Whipple's disease is a rare cause of encephalitis. Its diagnosis needs the confrontation of histology and PCR tests in multiple samples. The outcome with an adapted antibiotherapy may be very successful.

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.

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.

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).

[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.