A Pathophysiological Approach to Spontaneous Orbital Meningoceles: Case Report and Systematic Review.

BACKGROUND: Spontaneous orbital cephaloceles are a rare condition. The purpose of this study is to provide a description of a clinical case and to carry out a systematic literature review. METHODS: A systematic review of the English literature published on the Pubmed, Scopus, and Web of Science databases was conducted, according to the PRISMA recommendations. RESULTS: A 6-year-old patient was admitted for right otomastoiditis and thrombosis of the sigmoid and transverse sinuses, as well as the proximal portion of the internal jugular vein. Radiological examinations revealed a left orbital mass (22 × 14 mm) compatible with asymptomatic orbital meningocele (MC) herniated from the superior orbital fissure (SOF). The child underwent a right mastoidectomy. After the development of symptoms and signs of intracranial hypertension (ICH), endovascular thrombectomy and transverse sinus stenting were performed, with improvement of the clinical conditions and reduction of the orbital MC. The systematic literature review encompassed 29 publications on 43 patients with spontaneous orbital MC. In the majority of cases, surgery was the preferred treatment. CONCLUSIONS: The present case report and systematic review highlight the importance of ICH investigation and a pathophysiological-oriented treatment approach. The experiences described in the literature are limited, making the collection of additional data paramount.

Lung relapse pattern in children with metastatic Wilms tumor.

Wilms tumor is the most common pediatric renal cancer, and lungs represent the major site of metastasis and recurrence. Relapse occurs in 15%, months or years after treatment; so due to the small sample, acquiring more data about the pattern of lung relapse remains a challenge. The aim of our study was to evaluate if pulmonary relapse, detected by computed tomography (CT), occurred at the initial site of lung metastases or in a different location. According to our data, the CT pattern of lung relapse showed high probability of recurrence at the same site of initial metastasis.

Early neurological deterioration in patients with minor stroke due to isolated M2 occlusion undergoing medical management: a retrospective multicenter study.

BACKGROUND: Patients with minor stroke and M2 occlusion undergoing best medical management (BMM) may face early neurological deterioration (END) that can lead to poor long-term outcome. In case of END, rescue mechanical thrombectomy (rMT) seems beneficial. Our study aimed to define factors relevant to clinical outcome in patients undergoing BMM with the possibility of rMT on END, and find predictors of END. METHODS: Patients with M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score≤5 that received either BMM only or rMT on END after BMM were extracted from the databases of 16 comprehensive stroke centers. Clinical outcome measures were a 90-day modified Rankin Scale (mRS) score of 0-1 or 0-2, and occurrence of END. RESULTS: Among 10 169 consecutive patients with large vessel occlusion admitted between 2016 and 2021, 208 patients were available for analysis. END was reported in 87 patients that were therefore all subjected to rMT. In a logistic regression model, END (OR 3.386, 95% CI 1.428 to 8.032), baseline NIHSS score (OR 1.362, 95% CI 1.004 to 1.848) and a pre-event mRS score=1 (OR 3.226, 95% CI 1.229 to 8.465) were associated with unfavorable outcome. In patients with END, successful rMT was associated with favorable outcome (OR 4.549, 95% CI 1.098 to 18.851). Among baseline clinical and neuroradiological features, presence of atrial fibrillation was a predictor of END (OR 3.547, 95% CI 1.014 to 12.406). CONCLUSION: Patients with minor stroke due to M2 occlusion and atrial fibrillation should be closely monitored for possible worsening during BMM and, in this case, promptly considered for rMT.

The "SALPARE study" of spontaneous intracerebral haemorrhage-part 2-early CT predictors of outcome in ICH: keeping it simple.

BACKGROUND: The aim of this study was to investigate the prognostic role of hematoma characteristics and hematoma expansion (HE) in patients with spontaneous intracerebral hemorrhage (ICH). METHODS: This multicenter prospective cohort study enrolled consecutive adult patients with non-traumatic ICH admitted to three Italian academic hospitals (Salerno, Padova, Reggio Emilia) over a 2-year period. Early noncontrast CT (NCCT) features of the hematoma, including markers of HE, and 3-month outcome were recorded. Multivariable logistic regression analysis was performed to identify predictors of poor outcome. RESULTS: A total of 682 patients were included in the study [mean age: 73 ± 14 years; 316 (46.3%) females]. Pontine and massive hemorrhage, intraventricular bleeding, baseline hematoma volume > 15 mL, blend sign, swirl sign, margin irregularity ≥ 4, density heterogeneity ≥ 3, hypodensity ≥ 1, island sign, satellite sign, and black hole sign were associated with a higher risk of mortality and disability. However, at multivariate analysis only initial hematoma volume (OR 29.71) proved to be an independent predictor of poor functional outcome at 3 months. CONCLUSION: Simple hematoma volume measured on baseline CT best identifies patients with a worse outcome, while early NCCT markers of HE do not seem to add any clinically significant information.

Mechanical thrombectomy in minor stroke due to isolated M2 occlusion: a multicenter retrospective matched analysis.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of mechanical thrombectomy (MT) in patients with isolated M2 occlusion and minor symptoms and identify possible baseline predictors of clinical outcome. METHODS: The databases of 16 high-volume stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score ≤5 who received either early MT (eMT) or best medical management (BMM) with the possibility of rescue MT (rMT) on early neurological worsening. Because our patients were not randomized, we used propensity score matching (PSM) to estimate the treatment effect of eMT compared with the BMM/rMT. The primary clinical outcome measure was a 90-day modified Rankin Scale score of 0-1. RESULTS: 388 patients were initially selected and, after PSM, 100 pairs of patients receiving eMT or BMM/rMT were available for analysis. We found no significant differences in clinical outcome and in safety measures between patients receiving eMT or BMM/rMT. Similar results were also observed after comparison between eMT and rMT. Concerning baseline predicting factors of outcome, the involvement of the M2 inferior branch was associated with a favorable outcome. CONCLUSION: Our multicenter retrospective analysis has shown no benefit of eMT in minor stroke patients with isolated M2 occlusion over a more conservative therapeutic approach. Although our results must be viewed with caution, in these patients it appears reasonable to consider BMM as the first option and rMT in the presence of early neurological deterioration.

Transnasal Endoscopic Approach for Osteoid Osteoma of the Odontoid Process in a Child: Technical Note and Systematic Review of the Literature.

Osteoid osteoma (OO) is a primary benign tumor that accounts for up to 3% of all bone tumors. The cervical spine is less affected by OOs, and very few cases of C2 OOs have been reported in the literature, both in adults and children. Surgery may be required in case of functional torticollis, stiffness, and reduced range of motion (ROM) due to cervical OOs refractory to medical therapy. Several posterior and anterior surgical techniques have been described to remove C2 OOs. In particular, anterior approaches to the cervical spine represent the most used surgical route for treating C2 OOs. We describe the first case of OO of the odontoid process removed through a transnasal endoscopic approach with the aid of neuronavigation in a 6-year-old child. No intraoperative complications occurred, and the post-operative course was uneventful. The patient had immediate relief of neck pain and remained pain-free throughout the follow-up period, with complete functional recovery of the neck range of motion (ROM). In this case, based on the favorable anatomy, the transnasal endoscopic approach represented a valuable strategy for the complete removal of an anterior C2 OO without the need for further vertebral fixation since the preservation of ligaments and paravertebral soft tissue.

Pediatric Moyamoya Disease and Syndrome in Italy: A Multicenter Cohort.

Background: Moyamoya is a rare progressive cerebral arteriopathy, occurring as an isolated phenomenon (moyamoya disease, MMD) or associated with other conditions (moyamoya syndrome, MMS), responsible for 6-10% of all childhood strokes and transient ischemic attacks (TIAs). Methods: We conducted a retrospective multicenter study on pediatric-onset MMD/MMS in Italy in order to characterize disease presentation, course, management, neuroradiology, and outcome in a European country. Results: A total of 65 patients (34/65 women) with MMD (27/65) or MMS (38/65) were included. About 18% (12/65) of patients were asymptomatic and diagnosed incidentally during investigations performed for an underlying condition (incMMS), whereas 82% (53/65) of patients with MMD or MMS were diagnosed due to the presence of neurological symptoms (symptMMD/MMS). Of these latter, before diagnosis, 66% (43/65) of patients suffered from cerebrovascular events with or without other manifestations (ischemic stroke 42%, 27/65; TIA 32%, 21/65; and no hemorrhagic strokes), 18% (12/65) of them reported headache (in 4/12 headache was not associated with any other manifestation), and 26% (17/65) of them experienced multiple phenotypes (≥2 among: stroke/TIA/seizures/headache/others). Neuroradiology disclosed ≥1 ischemic lesion in 67% (39/58) of patients and posterior circulation involvement in 51% (30/58) of them. About 73% (47/64) of patients underwent surgery, and 69% (45/65) of them received aspirin, but after diagnosis, further stroke events occurred in 20% (12/61) of them, including operated patients (11%, 5/47). Between symptom onset and last follow-up, the overall patient/year incidence of stroke was 10.26% (IC 95% 7.58-13.88%). At last follow-up (median 4 years after diagnosis, range 0.5-15), 43% (26/61) of patients had motor deficits, 31% (19/61) of them had intellectual disability, 13% (8/61) of them had epilepsy, 11% (7/61) of them had behavioral problems, and 25% (13/52) of them had mRS > 2. The proportion of final mRS > 2 was significantly higher in patients with symptMMD/MMS than in patients with incMMS (p = 0.021). Onset age <4 years and stroke before diagnosis were significantly associated with increased risk of intellectual disability (p = 0.0010 and p = 0.0071, respectively) and mRS > 2 at follow-up (p = 0.0106 and p = 0.0009, respectively). Conclusions: Moyamoya is a severe condition that may affect young children and frequently cause cerebrovascular events throughout the disease course, but may also manifest with multiple and non-cerebrovascular clinical phenotypes including headache (isolated or associated with other manifestations), seizures, and movement disorder. Younger onset age and stroke before diagnosis may associate with increased risk of worse outcome (final mRS > 2).

Newly Diagnosed Multifocal GBM: A Monocentric Experience and Literature Review.

Glioblastomas with multiple foci at presentation (mGBMs) account for 2-35% of all GBMs. mGBMs have limited existing data and no standardized treatment. This study aims to determine their incidence, demographic and clinical features, outcome, and prognostic factors in terms of overall survival. We performed a monocentric retrospective study, reviewing patients treated at the Istituto Oncologico Veneto. Inclusion criteria were: new diagnosis of GBM and presence of multiple lesions on pre-treatment MRI. ECOG PS was used to evaluate clinical condition, RANO criteria for radiological assessment, and CTCAE v5.0 for treatment-related adverse events. The incidence of newly diagnosed mGBM was 7.2% and the study population consisted of 98 patients. Median age was 63 years, M:F ratio of 1.8:1, and a surgical approach was undertaken in 73 patients (mostly partial resection). MGMT was methylated in 47.5%, and 82 patients received active oncological treatment (65.9% radiotherapy plus temozolomide (RT + TMZ)). The disease control rate with RT + TMZ was 63%. Median OS of the entire study population was 10.2 months (95% CI 6.6-13.8), and median PFS was 4.2 months (95% CI 3.2-5.2). The ECOG PS, the extent of resection, and the RT + TMZ were significant prognostic factors in the univariate analysis for OS, but only the RT + TMZ was a significant independent OS predictor in the multivariate analysis (HR = 3.1, 95% IC 1.3-7.7, p = 0.014). The incidence of mGBM is not rare. RT + TMZ is confirmed to be an independent prognostic factor for survival and a safe and effective treatment. When feasible, RT + TMZ should be considered as a possible first-line treatment. The role of the extent of resection is still unclear.

PET/MR in recurrent glioblastoma patients treated with regorafenib: [18F]FET and DWI-ADC for response assessment and survival prediction.

OBJECTIVE: The use of regorafenib in recurrent glioblastoma patients has been recently approved by the Italian Medicines Agency (AIFA) and added to the National Comprehensive Cancer Network (NCCN) 2020 guidelines as a preferred regimen. Given its complex effects at the molecular level, the most appropriate imaging tools to assess early response to treatment is still a matter of debate. Diffusion-weighted imaging and O-(2-18F-fluoroethyl)-L-tyrosine positron emission tomography ([18F]FET PET) are promising methodologies providing additional information to the currently used RANO criteria. The aim of this study was to evaluate the variations in diffusion-weighted imaging/apparent diffusion coefficient (ADC) and [18F]FET PET-derived parameters in patients who underwent PET/MR at both baseline and after starting regorafenib. METHODS: We retrospectively reviewed 16 consecutive GBM patients who underwent [18F]FET PET/MR before and after two cycles of regorafenib. Patients were sorted into stable (SD) or progressive disease (PD) categories in accordance with RANO criteria. We were also able to analyze four SD patients who underwent a third PET/MR after another four cycles of regorafenib. [18F]FET uptake greater than 1.6 times the mean background activity was used to define an area to be superimposed on an ADC map at baseline and after treatment. Several metrics were then derived and compared. Log-rank test was applied for overall survival analysis. RESULTS: Percentage difference in FET volumes correlates with the corresponding percentage difference in ADC (R = 0.54). Patients with a twofold increase in FET after regorafenib showed a significantly higher increase in ADC pathological volume than the remaining subjects (p = 0.0023). Kaplan-Meier analysis, performed to compare the performance in overall survival prediction, revealed that the percentage variations of FET- and ADC-derived metrics performed at least as well as RANO criteria (p = 0.02, p = 0.024 and p = 0.04 respectively) and in some cases even better. TBR Max and TBR mean are not able to accurately predict overall survival. CONCLUSION: In recurrent glioblastoma patients treated with regorafenib, [18F]FET and ADC metrics, are able to predict overall survival and being obtained from completely different measures as compared to RANO, could serve as semi-quantitative independent biomarkers of response to treatment. ADVANCES IN KNOWLEDGE: Simultaneous evaluation of [18F]FET and ADC metrics using PET/MR allows an early and reliable identification of response to treatment and predict overall survival.

Endovascular treatment beyond 24 hours from the onset of acute ischemic stroke: the Italian Registry of Endovascular Thrombectomy in Acute Stroke (IRETAS).

BACKGROUND: Clinical trials and observational studies have demonstrated the benefit of thrombectomy up to 16 or 24 hours after the patient was last known to be well. This study aimed to evaluate the outcome of stroke patients treated beyond 24 hours from onset. METHODS: We analyzed the outcome of 34 stroke patients (mean age 70.7±12.3 years; median National Institutes of Health Stroke Scale (NIHSS) score 13) treated with endovascular thrombectomy beyond 24 hours from onset who were recruited in the Italian Registry of Endovascular Thrombectomy in Acute Stroke. Selection criteria for patients were: pre-stroke modified Rankin scale (mRS) score of ≤2, non-contrast CT Alberta Stroke Program Early CT score of ≥6, good collaterals on single phase CT angiography (CTA) or multiphase CTA, and CT perfusion mismatch with an infarct core size ≤50% of the total hypoperfusion extent or involving less than one-third of the extent of the middle cerebral artery territory evaluated by visual inspection. The primary outcome measure was functional independence assessed by the mRS at 90 days after onset. Safety outcomes were 90 day mortality and the occurrence of symptomatic intracranial hemorrhage (sICH). RESULTS: Successful recanalization (Thrombolysis in Cerebral Infarction score of 2b or 3) was present in 76.5% of patients. Three month functional independence (mRS score 0-2) was observed in 41.1% of patients. The case fatality rate was 26.5%. and the incidence of sICH was 8.8%. CONCLUSIONS: These findings suggest that, in a real world setting, very late endovascular therapy is feasible in appropriately selected patients.

Resection of the internal carotid artery in selected patients affected by cancer of the skull base.

Invasion of the internal carotid artery (ICA) has been historically considered a criterion of non-resectability of skull base cancer (SBC). Patients affected by SBC who underwent surgery including resection of ICA at two tertiary institutions were included. Demographics, oncologic, and surgical information, complications, and survival outcomes were retrospectively reviewed. Survival outcomes were calculated. Ten patients were included. Three surgical approaches (transnasal endoscopic, transorbital, and transpetrosal) were employed to resect the invaded/abutted tract(s) of the ICA. All patients underwent ICA temporary balloon occlusion test. In two patients, an extracranial-to-intracranial arterial bypass was harvested. Major neuromorbidity was observed in two patients. Perioperative mortality of the series was 10.0%. Mean overall survival was 27.2 months, with 2-year overall and progression-free survival rate of 88.9%. ICA resection is feasible as part of the ablation performed for very advanced SBCs. Survival outcomes are acceptable in adequately selected patients.

Preoperative Devascularization of Choroid Plexus Tumors: Specific Issues about Anatomy and Embolization Technique.

(1) Background: Surgical treatment of choroid plexus tumors is challenging, burdened by a notable risk of bleeding. Neoadjuvant chemotherapy and preoperative embolization have been attempted, with encouraging results; however, the consensus on these procedures is lacking. (2) Methods: We present a case of a 10-month-old girl who underwent preoperative embolization of a hemorrhagic choroid plexus carcinoma of the lateral ventricle via the anterior choroidal artery, followed by total resection. (3) Results: The endovascular procedure was successfully completed, despite the rectification of the anterior choroidal artery associated with the absence of flow proximal to the plexal point. Minimal bleeding was observed during resection and the patient remained neurologically intact. (4) Conclusions: The time from entrance to exit in the anterior choroidal artery should be monitored and regarded as a potential 'occlusion time' in this specific group of patients. Nevertheless, our case supports the feasibility and effectiveness of preoperative embolization of a choroid plexus carcinoma of the lateral ventricle via the anterior choroidal artery, without complications. Furthermore, we suggest the use of a fast-embolic agent, such as N-butyl cyanoacrylate glue, as the preferred agent for this specific pathology and patient population.

Mechanical thrombectomy in a pediatric patient with sedation aided by contralateral intra-arterial propofol injection: feasibility in an extreme condition.

Pediatric patients undergoing mechanical thrombectomy may be challenging for the anesthesiologists as regards the best anesthetic choice, especially if concomitant to severe comorbidities such as heart failure. A 16-year-old patient affected by arrhythmogenic right ventricle dysplasia/cardiomyopathy underwent mechanical thrombectomy. He was not eligible for deep sedation or general anesthesia since he has been suffering from severe heart failure. The patient stillness was obtained by intra-arterial injection of propofol from the contralateral internal carotid artery. The procedure has been well tolerated, without cardiorespiratory impairment. The case stresses the growing importance to tailor a proper anesthesiologic plan during mechanical thrombectomy, especially in extreme conditions.

COVID-19 challenge: proactive management of a Tertiary University Hospital in Veneto Region, Italy.

BACKGROUND: The aim of this study is to describe the successful emergency plan implemented by Padova University Hospital (AOUP) during the COVID-19 pandemic. METHODS: The emergency plan included early implementation of procedures aimed at meeting the increasing demand for testing and care while ensuring safe and timely care of all patients and guaranteeing the safety of healthcare workers. RESULTS: From 21 February to 1 May 2020, there were 3,862 confirmed cases of SARS-CoV-2 infection in the Province of Padua. A total of 485 patients were hospitalized in AOUP, of which 91 were admitted to the ICU; 12 .6% of admitted patients died. The average bed occupancy rate in the ICU was 61.1% (IQR 43.6%:77.4%). Inpatient surgery and inpatient admissions were kept for 76% and 74%, respectively, compared to March 2019. A total of 123,077 swabs were performed, 19.3% of which (23,725 swabs) to screen AOUP workers. The screening of all staff showed that 137 of 7,649 (1.8%) hospital workers were positive. No healthcare worker died. DISCUSSION: AOUP strategy demonstrated effective management of the epidemic thanks to the timely implementation of emergency procedures, a well-coordinated effort shared by all hospital Departments, and their continuous adjustment to the ongoing epidemic. Timely screening of all hospital workers proved to be particularly important to defend the hospital, avoiding epidemic clusters due to unknown positive cases.

Direct thrombectomy for stroke in the presence of absolute exclusion criteria for thrombolysis.

BACKGROUND: Intravenous thrombolysis (IVT)-ineligible patients undergoing direct thrombectomy tended to have poorer functional outcome as compared with IVT-eligible patients undergoing bridging therapy. We aimed to assess radiological and functional outcomes in large vessel occlusion-related stroke patients receiving direct thrombectomy in the presence of absolute exclusion criteria for IVT vs relative exclusion criteria for IVT and vs non-exclusion criteria for IVT. METHODS: A cohort study on prospectively collected data from 2282 patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke cohort for treatment with direct thrombectomy (n = 486, absolute exclusion criteria for IVT alone; n = 384, absolute in combination with relative exclusion criteria for IVT; n = 777, relative exclusion criteria for IVT alone; n = 635, non-exclusion criteria for IVT). RESULTS: After adjustment for unbalanced variables (model 1), ORs for 3-month death was higher in the presence of absolute exclusion criteria for IVT alone (vs relative exclusion criteria for IVT alone) (1.595, 95% CI 1.042-2.440) and in the presence of absolute exclusion criteria for IVT alone (vs non-exclusion criteria for IVT) (1.235, 95% CI 1.014-1.504). After adjustment for predefined variables (model 2: age, sex, pre-stroke mRS ≤ 1, NIHSS, occlusion in the anterior circulation, onset-to-groin time, and procedure time), ORs for 3-month death was higher in the presence of absolute exclusion criteria for IVT alone (vs relative exclusion criteria for IVT alone) (1.235, 95% CI 1.014-1.504) and in the presence of absolute exclusion criteria for IVT alone (vs non-exclusion criteria for IVT) (1.246, 95% CI 1.039-1.495). No significant difference was found between the groups as regards any type of intracerebral hemorrhage and parenchymal hematoma within 24 h, successful and complete recanalization after procedure, and modified Rankin Scale score 0-2 at 3 months. After adjustment for predefined variables of model 2, ORs for death were higher in the presence of recent administration of IV heparin (OR: 2.077), platelet count < 100,000/mm3 (OR: 4.798), bacterial endocarditis (OR: 15.069), neoplasm with increased hemorrhagic risk (OR: 6.046), and severe liver disease (OR: 6.124). CONCLUSIONS: Radiological outcomes were similar after direct thrombectomy in patients with absolute, relative, and non- exclusion criteria for IVT, while an increase of fatal outcome was observed in the presence of some absolute exclusion criterion for IVT.

Cardiac Myxoma as a Rare Cause of Pediatric Arterial Ischemic Stroke: Case Report and Literature Review.

BACKGROUND: Cardiac disorders are the second leading cause of pediatric arterial ischemic stroke (AIS). Limited literature is available on pediatric AIS caused by cardiac myxoma, a rare tumor in childhood. METHODS: We describe a new case of pediatric AIS due to a previously unknown atrial myxoma and we conduct a literature review on children with AIS due to cardiac myxoma. RESULTS: We identified 41 published pediatric cases of AIS and cardiac myxoma, including ours (56% males, median age at AIS was 11 years [range: 3-18]). AIS presentation was most frequently with hemiparesis/hemiplegia (89%). Multiple brain ischemic lesions were detected in 69% of patients, and arteriopathy in 91%. Seven patients underwent mechanical thrombectomy. At AIS presentation, 73% of children had one or more of the following clinical symptoms/signs suggesting a possible underlying cardiac myxoma: Carney's complex, cardiac auscultation abnormalities, extraneurological symptoms/signs, such as skin signs (12, 38, and 65%, respectively). Cardiac myxoma was diagnosed within 72 hours in 68% of cases. Death occurred in 11%, and 40% had persistent neurological deficits. CONCLUSION: Neurological presentation of AIS due to cardiac myxoma is similar to that of AIS with other etiologies, although clues suggesting a possible underlying cardiac myxoma can be detected in most cases. A timely diagnosis of cardiac myxoma in patients with AIS may favor prompt identification of candidates for endovascular therapy. Therefore, we suggest that in otherwise-healthy children presenting with AIS, transthoracic echocardiography should be performed early after stroke presentation.

A Step-by-Step Problem-Solving Strategy in a Patient With Heart Failure and Cerebral Aneurysm.

Left ventricular assist device implantation is an established treatment for patients with end-stage heart failure. The HeartMate 3 (Abbott Laboratories, Abbott Park, IL) is a continuous-flow centrifugal pump, recently introduced in the clinic, that has shown greater hemocompatibility compared with similar devices of previous generations. Nevertheless, anticoagulation is still required after HeartMate 3 implant to avoid pump dysfunction. Hereafter, we describe the case of a patient candidate to left ventricular assist device implantation for end-stage heart failure presenting a concomitant cerebrovascular lesion, accidentally found during preoperative assessment, that would have contraindicated the procedure (for the prohibitive risk of cerebral hemorrhage), unless a step by step problem-solving approach was adopted.

Accuracy of deep learning to differentiate the histopathological grading of meningiomas on MR images: A preliminary study.

BACKGROUND: Grading of meningiomas is important in the choice of the most effective treatment for each patient. PURPOSE: To determine the diagnostic accuracy of a deep convolutional neural network (DCNN) in the differentiation of the histopathological grading of meningiomas from MR images. STUDY TYPE: Retrospective. POPULATION: In all, 117 meningioma-affected patients, 79 World Health Organization [WHO] Grade I, 32 WHO Grade II, and 6 WHO Grade III. FIELD STRENGTH/SEQUENCE: 1.5 T, 3.0 T postcontrast enhanced T1 W (PCT1 W), apparent diffusion coefficient (ADC) maps (b values of 0, 500, and 1000 s/mm2 ). ASSESSMENT: WHO Grade II and WHO Grade III meningiomas were considered a single category. The diagnostic accuracy of the pretrained Inception-V3 and AlexNet DCNNs was tested on ADC maps and PCT1 W images separately. Receiver operating characteristic curves (ROC) and area under the curve (AUC) were used to asses DCNN performance. STATISTICAL TEST: Leave-one-out cross-validation. RESULTS: The application of the Inception-V3 DCNN on ADC maps provided the best diagnostic accuracy results, with an AUC of 0.94 (95% confidence interval [CI], 0.88-0.98). Remarkably, only 1/38 WHO Grade II-III and 7/79 WHO Grade I lesions were misclassified by this model. The application of AlexNet on ADC maps had a low discriminating accuracy, with an AUC of 0.68 (95% CI, 0.59-0.76) and a high misclassification rate on both WHO Grade I and WHO Grade II-III cases. The discriminating accuracy of both DCNNs on postcontrast T1 W images was low, with Inception-V3 displaying an AUC of 0.68 (95% CI, 0.59-0.76) and AlexNet displaying an AUC of 0.55 (95% CI, 0.45-0.64). DATA CONCLUSION: DCNNs can accurately discriminate between benign and atypical/anaplastic meningiomas from ADC maps but not from PCT1 W images. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1152-1159.