Is non-contrast MRI sufficient to detect meningioma residue after surgery?

BACKGROUND: Contrast-enhanced magnetic resonance imaging (MRI) is the imaging modality routinely used to follow up patients who have undergone surgical resection of brain meningiomas. There are growing concerns about the massive use of gadolinium-based contrast agents (GBCA). Our aim was to evaluate the performance of a new imaging protocol, performed without GBCA injection, in the detection of tumoral residue or local recurrence after surgery of parafalcine and convexity meningiomas. MATERIALS AND METHODS: Only adult patients with a documented resected parafalcine or convexity meningioma were included. We performed a dedicated MRI protocol that included non-contrast and post-contrast sequences. The presence or absence of residue on the unenhanced sequences was independently recorded by three observers: first blindly, then in comparison with a baseline enhanced MRI examination. RESULTS: A total of 51 patients were included. 37 of them featured a tumor residue on the reference enhanced sequence. Overall, an average of 32 of 37 (87%) residues were identified on the unenhanced sequences that were blindly reviewed; and more than 34 of 37 (93%) were identified with the help of the comparative baseline enhanced examination, with a high sensitivity. The missed cases were related to small residues. CONCLUSION: Unenhanced MRI sequences are highly sensitive and specific in identifying a tumor residue or a local recurrence in the post operative follow up of brain meningiomas. Sensitivity is even higher with the help of a comparative baseline enhanced MRI examination, whatever the strength of magnetic field.

Unravelling the etiology of sporadic late-onset cerebellar ataxia in a cohort of 205 patients: a prospective study.

BACKGROUND: Despite recent progress in the field of genetics, sporadic late-onset (> 40 years) cerebellar ataxia (SLOCA) etiology remains frequently elusive, while the optimal diagnostic workup still needs to be determined. We aimed to comprehensively describe the causes of SLOCA and to discuss the relevance of the investigations. METHODS: We included 205 consecutive patients with SLOCA seen in our referral center. Patients were prospectively investigated using exhaustive clinical assessment, biochemical, genetic, electrophysiological, and imaging explorations. RESULTS: We established a diagnosis in 135 (66%) patients and reported 26 different causes for SLOCA, the most frequent being multiple system atrophy cerebellar type (MSA-C) (41%). Fifty-one patients (25%) had various causes of SLOCA including immune-mediated diseases such as multiple sclerosis or anti-GAD antibody-mediated ataxia; and other causes, such as alcoholic cerebellar degeneration, superficial siderosis, or Creutzfeldt-Jakob disease. We also identified 11 genetic causes in 20 patients, including SPG7 (n = 4), RFC1-associated CANVAS (n = 3), SLC20A2 (n = 3), very-late-onset Friedreich's ataxia (n = 2), FXTAS (n = 2), SCA3 (n = 1), SCA17 (n = 1), DRPLA (n = 1), MYORG (n = 1), MELAS (n = 1), and a mitochondriopathy (n = 1) that were less severe than MSA-C (p < 0.001). Remaining patients (34%) had idiopathic late-onset cerebellar ataxia which was less severe than MSA-C (p < 0.01). CONCLUSION: Our prospective study provides an exhaustive picture of the etiology of SLOCA and clues regarding yield of investigations and diagnostic workup. Based on our observations, we established a diagnostic algorithm for SLOCA.

Cerebral aspergillosis in the era of new antifungals: The CEREALS national cohort study Nationwide CEREbral Aspergillosis Lesional study (CEREALS).

BACKGROUND: Cerebral aspergillosis (CA) is a life-threatening disease for which diagnosis and management remain challenging. Detailed analyses from large cohorts are lacking. METHODS: We included 119 cases of proven (n = 54) or probable (n = 65) CA diagnosed between 2006 and 2018 at 20 French hospitals. Data were collected at baseline and during follow-up. Cerebral imaging was reviewed centrally by two neuroradiologists. RESULTS: The most frequent underlying conditions were hematological malignancy (40%) and solid organ transplantation (29%). Galactomannan was detected in the serum of 64% of patients. In 75% of cases, at least one of galactomannan, Aspergillus PCR, and ß-d-glucan was positive in the cerebrospinal fluid. Six-week mortality was 45%. Two distinct patterns of disease were identified according to presumed route of dissemination. Presumed haematogenous dissemination (n = 88) was associated with a higher frequency of impaired consciousness (64%), shorter time to diagnosis, the presence of multiple abscesses (70%), microangiopathy (52%), detection of serum galactomannan (69%) and Aspergillus PCR (68%), and higher six-week mortality (54%). By contrast, contiguous dissemination from the paranasal sinuses (n = 31) was associated with a higher frequency of cranial nerve palsy (65%), evidence of meningitis on cerebral imaging (83%), macrovascular lesions (61%), delayed diagnosis, and lower six-week mortality (30%). In multivariate analysis and in a risk prediction model, haematogenous dissemination, hematological malignancy and the detection of serum galactomannan were associated with higher six-week mortality. CONCLUSION: Distinguishing between hematogenous and contiguous dissemination patterns appears to be critical in the workup for CA, as they are associated with significant differences in clinical presentation and outcome.

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.

Torquetenovirus viremia for early prediction of graft rejection after kidney transplantation.

OBJECTIVES: New biomarkers reflecting the degree of immunosuppression in transplant recipients are needed to provide an optimal personalized balance between rejection and infection risks. METHODS: For this purpose, we investigated TTV viremia dynamics in 66 kidney transplant recipients followed up for two years after transplantation, in relation to BK virus infection and graft rejection. RESULTS: After transplantation, TTV viremia rose by ≥2 log10 copies/mL from baseline to month 3, then declined by ≥1 log10 copies/mL thereafter. Higher TTV viremia was associated with recipients of a deceased donor, a lower count of CD8+ T cells and a higher BKV viremia. Importantly, TTV loads were significantly lower in KTR who would later display graft rejection; indeed, patients with TTV viremia lower than 3.4 log10 copies/mL at transplantation or lower than 4.2 log10 copies/mL at month 1 had a higher risk of developing graft rejection in the two following years (hazard ratio (HR) at D0 = 7.30, p = 0.0007 and HR at M1 = 6.16, p = 0.001). CONCLUSIONS: TTV viremia measurement at early times post transplantation predicts graft rejection and would represent a useful tool to improve kidney transplant monitoring.

The usefulness of fibrin glue as a support in the dissection of malignant cystic brain tumors.

BACKGROUND: If the complete microsurgical resection of a brain tumor is a logical oncologic goal, the surgical strategy for the cystic component remains controversial secondary to the risk of morbidity. The objective of this study was to analyze the interest of using fibrin glue in the resection of malignant cystic brain tumors (MCBT). METHODS: Seven patients (median: 60-years-old (range [52-72]/sex ratio M/F: 2.5) were analyzed prospectively in the Neurosurgery Department at Strasbourg University Hospital, from October 2014 to November 2016. The surgical technique consisted of injecting fibrin glue into the tumor cyst after partial drainage. After the solidification of the glue, the cysts walls were removal by following the dissection plan around the fibrin glue. The primary objective was to evaluate the quality of surgical resection on brain MRI scans postoperatively with the use of ITK-SNAP software for precise measurements of tumor volume. RESULTS: Four metastases and 3 glial lesions were operated on with this technique. An average reduction in cystic volume of 64.6% (P=0.016) and 82.1% (P=0.016) for contrast enhancement volume were observed. If two cases (#2 and #7) were excluded, the average contrast enhancement reduction was respectively 94% and 72% for the cystic volume. In addition, there were no complications, tumor recurrence or difference between gliomas and metastases and the Karnofsky score increased by at least 10% in all patients. CONCLUSION: This procedure allowed to extend the resection to the cystic component of MCBT without increasing the risk of morbidity related to injury on the underlying parenchyma.

Deciphering the causes of sporadic late-onset cerebellar ataxias: a prospective study with implications for diagnostic work.

The management of sporadic late-onset cerebellar ataxias represents a very heterogeneous group of patients and remains a challenge for neurologist in clinical practice. We aimed at describing the different causes of sporadic late-onset cerebellar ataxias that were diagnosed following standardized, exhaustive investigations and the population characteristics according to the aetiologies as well as at evaluating the relevance of these investigations. All patients consecutively referred to our centre due to sporadic, progressive cerebellar ataxia occurring after 40 years of age were included in the prospective, observational study. 80 patients were included over a 2 year period. A diagnosis was established for 52 patients (65%) corresponding to 18 distinct causes, the most frequent being cerebellar variant of multiple system atrophy (n = 29). The second most frequent cause was inherited diseases (including spinocerebellar ataxias, late-onset Friedreich's disease, SLC20A2 mutations, FXTAS, MELAS, and other mitochondrial diseases) (n = 9), followed by immune-mediated or other acquired causes. The group of patient without diagnosis showed a slower worsening of ataxia (p < 0.05) than patients with multiple system atrophy. Patients with later age at onset experienced faster progression of ataxia (p = 0.001) and more frequently parkinsonism (p < 0.05) than patients with earlier onset. Brain MRI, DaT scan, genetic analysis and to some extent muscle biopsy, thoracic-abdominal-pelvic tomodensitometry, and cerebrospinal fluid analysis were the most relevant investigations to explore sporadic late-onset cerebellar ataxia. Sporadic late-onset cerebellar ataxias should be exhaustively investigated to identify the underlying causes that are numerous, including inherited causes, but dominated by multiple system atrophy.

Thalamic rosette-forming a glioneuronal tumor in an elderly patient: Case report and literature review.

The rosette-forming glioneuronal tumor (RGNT) is a novel type of brain tumor recently listed in the WHO 2007 classification of central nervous system (CNS) tumors. We report the case of a 75-year-old woman harboring a thalamic RGNT with third ventricle dissemination. Age and location make the present case exceptional and which has never previously been reported. A review of the clinical, pathological and radiological features is presented along with the relevant literature.

Current and future imaging of the peripheral nervous system.

Peripheral nervous system (PNS) imaging is usually carried out by ultrasound and MRI. Thanks to its wide availability and excellent spatial resolution, ultrasound is a mature investigation with clearly established indications, particularly in entrapment syndromes and tumors. MRI is generally a second-line examination, which provides decisive additional information thanks to its excellent contrast resolution and its multiplanar abilities. This review describes the current methods for imaging the PNS, concentrating on acquisition techniques, normal results and basic pathological semiology. Ongoing and future developments are described in order to underline the forthcoming changes in this very dynamic field of musculoskeletal radiology.

[The spinal canal: from imaging anatomy to diagnosis]. / Espaces rachidiens intracanalaires: de l'anatomie radiologique au diagnostic étiologique.

The spinal canal is divided into epidural, subdural and subarachnoid spaces. Intraspinal processes should be correctly placed into their space of origin. MRI is the best imaging modality to achieve this task. Accurate determination of the space of origin routinely requires the acquisition of two different pulse sequences, typically T1W and T2W images, in two orthogonal planes, usually axial and sagittal. Simple imaging features can assist in determining the site of origin: changes to the epidural fat, compression or widening of subarachnoid spaces. The epidural space, bordered medially by dura, contains fat and vascular structures. The subdural space is a virtual space in between the dura and arachnoid membrane. The subarachnoid space is home to the CSF, spinal cord and nerve rootlets. An epidural process replaces the epidural fat, displaces the dura and narrows the subarachnoid space. A subarachnoid process widens the subarachnoid space and spares the epidural fat. Epidural processes usually are infectious or tumoral, either primary or secondary to spinal involvement. Subarachnoid processes include primary tumors, leptomeningeal metastases, arachnoiditis and hemorrhage. Nerve sheath tumors and meningiomas are the most frequent intradural extramedullary tumors.

[Imaging of non-traumatic and non-tumoral cord lesions]. / Imagerie des lésions médullaires non traumatiques et non tumorales.

There is a wide range of spinal cord pathologies (vascular, inflammatory, infectious, metabolic, degenerative). They present clinically as acute partial or complete cord syndromes, or chronic myelopathies (more than 4 weeks in duration). MRI examination should be undertaken with a very strict protocol. Spinal cord lesions should be evaluated with regards to their T1W and T2W signal characteristics, involvement of grey and/or white matter, axial and sagittal extension, cord volume changes, contrast uptake and associated lesions (perimedullary, radicular or brain). The correlation of MR imaging features with clinical and biological data (blood and CSF) should suggest a differential diagnosis.

Diagnostic accuracy of mammography readers and their memory performance have no correlation with each other.

INTRODUCTION: The study aims to determine if any association exists between visual memory performance and diagnostic accuracy performance in a group of radiologist mammogram readers. MATERIALS AND METHODS: One hundred proven mammograms (23 with cancers) were grouped into 5 sets of 20 cases, with sets being of equal difficulty. Pairs of sets were presented in 5 reads (40 cases per read, order random) to a panel of 8 radiologist readers (either present or past screening readers, with experience range from <1 year to >20 years). The readers were asked to either 'clear' or 'call back' cases depending on need for further workup, and at post-baseline reads to indicate whether each case was 'new' or 'old' (i.e. remembered from prior read). Two sets were presented only at baseline (40 cases per reader), and were used to calculate the reader's false recollection rate. Three sets were repeated post-baseline once or twice (100 cases per reader). Reading conditions were standardised. RESULTS: Memory performance differed markedly between readers. The number of correctly remembered cases (of 100 'old' cases) had a median of 10.5 and range of 0-58. The observed number of false recollections (of 40 'totally new' cases) had a median of 2 and range of 0-17. Diagnostic performance measures were mean (range): sensitivity 0.68 (0.54-0.81); specificity 0.82 (0.74-0.91); positive predictive value (PPV) 0.55 (0.50-0.65); negative predictive value (NPV) 0.89 (0.86-0.93) and accuracy 0.78 (0.76-0.83). Confidence intervals (CIs; 95%) for each reader overlapped for all the diagnostic parameters, indicating a lack of statistically significant difference between the readers at the 5% level. The most sensitive and the most specific reader showed a trend away from each other on sensitivity, specificity, NPV and PPV; their accuracies were 0.76 and 0.82, respectively, and their accuracy 95% CIs overlapped considerably. Correlation analysis by reader showed no association between observed memory performance and any of the diagnostic accuracy measures in our group of readers. In particular, there was no correlation between diagnostic accuracy and memory performance. CONCLUSION: There was no association between visual memory performance and diagnostic accuracy as a screening mammographer in our group of eight representative readers. Whether a radiologist has a good or a bad visual memory for cases, and in particular mammograms, should not impact on his or her performance as a radiologist and mammogram reader.

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.

[Postoperative ischemic acute stroke and thrombolytic therapy]. / Thrombolyse postopératoire immédiate dans un contexte d'accident vasculaire sylvien gauche.

Intravenous thrombolytic therapy for ischemic stroke was performed on a 75-year-old patient at recovery from cervicocephalic superficial surgery. The patient recovered totally from ischemic stroke and no neurologic sequelae was observed. Thrombolytic therapy must be performed in an intensive care unit in order to manage some bleeding events which can occur.

Apparent diffusion coefficient values of middle ear cholesteatoma differ from abscess and cholesteatoma admixed infection.

A retrospective study was conducted on a cohort of 15 patients who underwent surgery because cholesteatoma or abscess was suspected. All patients had MR imaging prior to surgery with diffusion-weighted images (DWI) from which the apparent diffusion coefficient (ADC) value was calculated. Using this technique, we were able to determine 3 distinct ADC value ranges corresponding to the 3 groups of lesions found at surgery (pure cholesteatoma, cholesteatoma with infection, and abscess or infection). This needs to be confirmed by further studies with a wider range of patients.

Leptomeningeal carcinomatosis and sensorineural hearing loss: correlation of labyrinthine enhancement patterns with symptoms.

OBJECTIVES: The purpose of this study was to investigate the correlation between hearing loss and inner ear enhancement in patients suffering from leptomeningeal carcinomatosis (LC) involving the internal acoustic canal (IAC). Previous studies have only reported an association between IAC enhancement and sensorineural deafness. MATERIAL AND METHODS: In a prospective study conducted from 2005 to 2007, 14 patients with LC involving the IAC underwent high-resolution MRI and otolaryngology examination. MRI images were analyzed by two experienced radiologists who were blinded to audiologic investigation results. RESULTS: Three (21%) patients had IAC and inner ear enhancement on gadolinium-weighted MRI. All three had a sensorineural hearing loss. Eleven (79%) patients had IAC enhancement without inner ear enhancement. Nine of these 11 patients were free of sensorineural hearing loss. Only two of them had sensorineural deafness. CONCLUSION: These findings are suggestive of a relation between hearing loss and inner ear enhancement in leptomeningeal carcinomatosis, as previously reported for bacterial meningitis. However, further investigations, including radiopathological correlation and a larger number of patients, are warranted to confirm these preliminary results.