Artificial intelligence applied in acute ischemic stroke: from child to elderly.

This review will summarize artificial intelligence developments in acute ischemic stroke in recent years and forecasts for the future. Stroke is a major healthcare concern due to its effects on the patient's quality of life and its dependence on the timing of the identification as well as the treatment. In recent years, attention increased on the use of artificial intelligence (AI) systems to help categorize, prognosis, and to channel these patients toward the right therapeutic procedure. Machine learning (ML) and in particular deep learning (DL) systems using convoluted neural networks (CNN) are becoming increasingly popular. Various studies over the years evaluated the use of these methods of analysis and prediction in the assessment of stroke patients, and at the same time, several applications and software have been developed to support the neuroradiologists and the stroke team to improve patient outcomes.

Temporal bone CT-based anatomical parameters associated with the development of cholesteatoma.

BACKGROUND: Cholesteatoma is caused by disorders of the middle ear ventilation that trigger a progressive series of events responsible for its formation. The aim of this study was to identify possible radiological CT-derived parameters predisposing to ventilation disorders and cholesteatoma. METHODS: In this retrospective study, patients diagnosed with cholesteatomatous chronic otitis media who underwent temporal bone CT and open tympanoplasty surgery have been included, as well as control patients with clinical examination negative for organic otological pathology who underwent temporal bone CT for other reasons. For each patient, the following parameters have been extracted from CT volumes: degree of mastoid pneumatization, prominence of the cog, patency of the Eustachian tube, antrum width, aditus width, anterior and posterior epitympanic widths, and epitympanic height. RESULTS: Sixty patients have been included, thirty of whom belonged to the group of patients with cholesteatoma and the remaining part to the group of patients without organic otological pathology. The prevalence of a low degree of mastoid pneumatization was significantly higher among patients with cholesteatoma, as well as for the prevalence of cog prominence (p < 0.001). All the continuous variables were found to have statistical significance (p < 0.05) in the comparison between groups except for the width of the antrum. CONCLUSION: Mastoid pneumatization degree, prominence of the cog and epitympanic measures based on temporal bone CT could be good radiological correlates of the ventilatory capabilities of the epitympanum which, if compromised, can facilitate the development of cholesteatoma.

Artificial intelligence and radiation effects on brain tissue in glioblastoma patient: preliminary data using a quantitative tool.

PURPOSE: The quantification of radiotherapy (RT)-induced functional and morphological brain alterations is fundamental to guide therapeutic decisions in patients with brain tumors. The magnetic resonance imaging (MRI) allows to define structural RT-brain changes, but it is unable to evaluate early injuries and to objectively quantify the volume tissue loss. Artificial intelligence (AI) tools extract accurate measurements that permit an objective brain different region quantification. In this study, we assessed the consistency between an AI software (Quibim Precision® 2.9) and qualitative neruroradiologist evaluation, and its ability to quantify the brain tissue changes during RT treatment in patients with glioblastoma multiforme (GBM). METHODS: GBM patients treated with RT and subjected to MRI assessment were enrolled. Each patient, pre- and post-RT, undergoes to a qualitative evaluation with global cerebral atrophy (GCA) and medial temporal lobe atrophy (MTA) and a quantitative assessment with Quibim Brain screening and hippocampal atrophy and asymmetry modules on 19 extracted brain structures features. RESULTS: A statistically significant strong negative association between the percentage value of the left temporal lobe and the GCA score and the left temporal lobe and the MTA score was found, while a moderate negative association between the percentage value of the right hippocampus and the GCA score and the right hippocampus and the MTA score was assessed. A statistically significant strong positive association between the CSF percentage value and the GCA score and a moderate positive association between the CSF percentage value and the MTA score was found. Finally, quantitative feature values showed that the percentage value of the cerebro-spinal fluid (CSF) statistically differences between pre- and post-RT. CONCLUSIONS: AI tools can support a correct evaluation of RT-induced brain injuries, allowing an objective and earlier assessment of the brain tissue modifications.

Utility of virtual stenting in treatment of cerebral aneurysms by flow diverter devices.

Successful endovascular treatment by stenting of intracranial aneurysms requires proper placement of the device and appropriate choice of its diameter and length. To date, several methods have been employed to achieve these goals, although each has inherent critical issues. Recently developed stent planning software applications can be used to assist interventional neuroradiologists. Based on a 3D-DSA image acquired before stenting, these applications simulate and visualize the final placement of the deployed stent. In this single-centre retrospective study, 27 patients undergoing an intravascular procedure for the treatment of intracranial aneurysms from June 2019 to July 2020 were evaluated according to strict inclusion criteria. Stent virtualization was performed with Syngo 3D Aneurysm Guidance Neuro software. We compared the software-generated stent measurement and measurements taken by the interventional radiologist. Statistical analysis was performed using the STAC web platform. Mean and standard deviations of absolute and relative discrepancies between predicted and implanted stents were recorded. Friedman's nonparametric test was used to refute the null hypotheses, i.e. (I) discrepancies between the size of virtual and implanted stents would occur, and (II) operator influence does not affect the outcome of the virtual stenting process. Based on these observations, it is believed that the virtual stenting process can validly assist interventional neuroradiologists in selecting the appropriate device and reducing peri- and post-procedural complications. The results of our study suggest that virtual reality simulation of devices used for endovascular treatment of intracranial aneurysms is a useful, rapid, and accurate tool for interventional procedure planning.

Efficacy of recanalization therapy for ischemic stroke: multicenter hospital network experience.

PURPOSE: Stroke is a leading cause of long-term disability with high mortality rate in the first year after the event. In Campania, mechanical thrombectomy treatment significantly increases in the last 3 years, as well as hospitals delivering acute stroke treatments. The aim of this study is to demonstrate how a full opening of our stroke network improves stroke management and stroked patients' survival in Campania. MATERIAL AND METHODS: In Federico II University Hospital of Naples acting as a HUB center of 7 peripheral SPOKE hospitals in regional territory, 68 patients with acute ischemic stroke were evaluated with NIHSS and m-RS clinical scores and neuroradiological ASPECT scores, from January 1 to December 31, 2021. At hospital discharge, NIHSS score and three months after m-RS score were re-assessed to evaluate the therapeutic effects. RESULTS: Forty-two of 68 patients (63%) admitted to our hub center had ischemic acute stroke at CT evaluation; 29 patients had ASPECT score > 7 (69%), and 6 a score < 7 (14%). At admission, NIHSS score mean value was 10.75, and m-RS score mean value was 0.74. At discharge, NIHSS score mean value was 7.09. After three months, m-RS score mean value was 0.74. DISCUSSION: The inter-company agreement between Federico II University and several peripheral hospitals allows an absolute and relative increase in endovascular mechanical thrombectomy and intravenous thrombolysis procedures, with a relative prevalence of mechanical thrombectomy. A regional implementation of the stroke multi-disciplinary care system is hardly needed to ensure the optimum treatment for the largest number of patients, improving patient's outcome.

Trends of recanalization therapies and state of art for ischemic stroke treatment in Campania region, Italy.

BACKGROUND: According to the last Italian report by the Ministry of Health in 2018, the estimated number of acute ischemic strokes (AIS) in Campania is 10,000/year, with an expected number of 1390 intravenous thrombolysis (IVT) and 694 mechanical thrombectomies (MT). In 2017, only 1.5% of expected patients received IVT and 0.2% MT. This study analyzed the trend of IVT and MT in 2019-2020 and depicted the state of art of Stroke Care in Campania. METHODS: From the regional health task force, we obtained the hospital discharge forms from all private and public hospitals in Campania; we selected patients with a principal diagnosis of AIS and measured the rate of patients admitted to neurology units and the rate of IVT, MT, and IVT + MT for both 2019 and 2020. RESULTS: In 2019, we observed 4817 admissions for AIS; 2858/4817 (59.3%) patients were admitted to neurology units. Out of 4817 patients, 192 received IVT, 165 MT, and 131 IVT + MT (488 treated patients; 10.1%). In 2020, we observed 4129 admissions for AIS; 2502/4129 (62.7%) patients were admitted to neurology units. Out of 4129 patients, 198 received IVT, 250 MT, and 180 IVT + MT (628 treated patients; 15.2%). These results showed that despite a reduction of AIS admissions in 2020, the relative and absolute rate of recanalization treatments increased. However, the number of patients who were not admitted to neurology units nor received acute treatments remained dramatically high. CONCLUSION: Despite the development of acute treatments, the Campania Stroke Network still needs significative efforts to improve.

Extra-Neural Metastases of Late Recurrent Myxopapillary Ependymoma to Left Lumbar Paravertebral Muscles: Case Report and Review of the Literature.

Ependymomas are commonly classified as low-grade tumors, although they may harbor a malignant behavior characterized by distant neural dissemination and spinal drop metastasis. Extra-CNS ependymoma metastases are extremely rare and only few cases have been reported in the lung, lymph nodes, pleura, mediastinum, liver, bone, and diaphragmatic, abdominal, and pelvic muscles. A review of the literature yielded 14 other case reports metastasizing outside the central nervous system, but to our knowledge, no studies describe metastasis in the paravertebral muscles. Herein, we report the case of a 39-year-old patient with a paraspinal muscles metastasis from a myxopapillary ependymoma. The neoplasm was surgically excised and histologically and molecularly analyzed. Both the analyses were consistent with the diagnosis of muscle metastases of myxopapillary ependymoma. The here-presented case report is first case in the literature of a paraspinal muscles metastasis of myxopapillary ependymoma.

Dissective tandem stroke: an endovascular approach.

Ischemic stroke due to internal carotid artery occlusion is a potential devastating condition. More frequently the occlusions are embolic in nature, but sometimes they are caused by arterial dissection and their treatment is a challenge. We describe an illustrative case where a young patient with middle cerebral artery stroke caused by carotid artery dissection was submitted to endovascular treatment of mechanical thrombectomy and stenting, giving an excellent outcome. We believe that tandem approach is a treatment of choice in these cases.

Basilar Artery Occlusion (BAO) revascularization after more than 12 hours from the onset of symptoms with excellent outcome: Report of a case.

This paper reports a case of basilar artery occlusion (BAO), a relatively rare event associated with high mortality rate and high risk of disability. A 77-year-old man arrived at our Stroke Unit approximately 14 hours after the onset of symptoms (dysarthria and complete left hemiparesis) with progressive worsening up to coma and with a National Institute Health Stroke Scale (NIHSS) of 22. The patient was treated and, at discharge, the modified Rankin scale and NIHSS were 2 and 5, respectively. The aim of this paper is to illustrate how revascularization treatment, also after 12 hours, could be a viable option to ensure survival and a good life quality for the patient. Furthermore, it is essential to encourage the publication of a greater number of trials about the posterior circulation emphasizing how many favorable prognosis indicators are now recognized.

Long-term follow-up of the Derivo® Embolization Device (DED®) for intracranial aneurysms: the Italian Multicentric Registry.

BACKGROUND: The flow-diverter devices (FDDs) safety and effectiveness have been demonstrated by large series and meta-analyses. Due to the high occlusion rates and the acceptable morbidity rates of FDDs, the indications for their use are continuously expanding. We presented our Italian multicentric experience using the second generation of DERIVO® Embolization Device (DED®; Acandis, Pforzheim, Germany) to cure cerebral aneurysms, evaluating both middle and long-term safety and efficacy of this device. METHODS: Between July 2016 and September 2017 we collected 109 consecutive aneurysms in 108 patients treated using DED® during 109 endovascular procedures in 34 Italian centers (100/109 aneurysms were unruptured, 9/109 were ruptured). The collected data included patient demographics, aneurysm location and characteristics, baseline angiography, adverse event and serious adverse event information, morbidity and mortality rates, and pre- and post-treatment modified Rankin Scale scores. Midterm and long-term clinical, angiographic and cross-sectional CT/MR follow-up were recorded and collected until December 2018. RESULTS: In 2/109 cases, DED® placement was classified as technical failures. The overall mortality and morbidity rates were respectively 6.5% and 5.5%. Overall DERIVO® related mortality and morbidity rates were respectively 0% and 4.6% (5 out of 108 patients). Midterm neuroimaging follow-up showed the complete or nearly complete occlusion of the aneurysm in 90% cases, which became 93% at long-term follow-up. Aneurysmal sac shrinking was observed in 65% of assessable aneurysms. CONCLUSIONS: Our multicentric experience using DED® for endovascular treatment of unruptured and ruptured aneurysms showed a high safety and efficacy profile, substantially equivalent or better compared to the other FDDs.

Upper Eyelid Isolated Arterio-Venous Malformation Treated With Embolization in a Patient With Keloid-Prone Skin.

Ocular adnexal aterio-venous malformations (AVMs) are rare congenital disabling anomalies, which may enlarge causing disfiguring deformity and rarely severe hemorrhage. These lesions are generally treated by preliminary endovascular embolization to shrink the arterio-venous malformation, followed by surgical gross total resection. The authors report a case of eyelid arterio-venous malformation in a 12-year-old girl, which progressively increased in size in few months. The patient complained mild itching, blurring of the vision, and mild tenderness. Magnetic resonance imaging showed an expansive mass with multiple arterial vessels at the left superior eyelid and left forehead. The diagnosis of arterio-venous malformation was then confirmed by digital subtraction angiography. Primary surgical excision was excluded because of the high risk of intrasurgical bleeding. Embolization through superselective cannulation of the left external carotid feeder vessels was performed resulting in flow exclusion up to the 80% of the nidus. Subsequent surgical resection was not recommended due to clinical evidence of keloid-prone skin.

Pituitary magnetic resonance imaging vs. bilateral inferior petrosal sinus sampling: comparison between non-invasive and invasive diagnostic techniques for Cushing's disease-a narrative review.

Cushing's syndrome is a pathological clinical condition caused by an exposure of elevated cortisol levels over a long period of time. It is therefore essential to establish what the cause of hypercortisolism is. In most cases (about 80%) the pathological process is due to adrenocorticotropic hormone (ACTH), while in a minor part of the cases (about 20%) the cause is represented by a pathology of the adrenal glands and therefore not related to ACTH. Most patients with ACTH dependent Cushing's syndrome have a pituitary microadenoma; in the remaining cases (30%), the high level of cortisol is linked to an ectopic secretion of ACTH. Surgical removal of the pituitary adenoma represents the treatment of choice in Cushing's disease (CD) patients; it is therefore necessary to identify and precisely locate the pituitary tumour responsible for the secretion of ACTH. Adequate diagnostic information is very often, even with magnetic resonance imaging (MRI), and in these cases we rely on bilateral inferior petrosal sinuses sampling (BIPSS). This procedure is considered the gold standard method for the diagnosis, but like any other diagnostic method it is not free from erroneous results such as false positives or false negatives.

Carotid Cavernous Fistulas and Dural Arteriovenous Fistulas of the Cavernous Sinus: Validation of a New Classification According to Venous Drainage.

BACKGROUND: Multiple carotid cavernous fistula (CCF) classifications have been proposed. However, they lacked predictive factors for the clinical presentation, natural history, and hemorrhagic risk. Our aim was to externally validate a new classification according to venous drainage (i.e., the Thomas classification [TC]) to assess its relationship with symptoms, endovascular treatment, and outcomes. METHODS: We performed a multicenter retrospective review of CCFs at 2 major academic institutions. The CCFs were classified using the Barrow classification (BC) and TC systems. RESULTS: The data from 94 patients with a diagnosis of CCF were collected during a study period 23 years, 4 months. Of these 94 patients, 89 had undergone CCF treatment and 5 had experienced spontaneous occlusion. Complete occlusion was achieved in 89.9% of the treated patients. Complications occurred in 5.3% of the patients, including permanent deficits in 2.1%. TC type 4 was associated with cortical symptoms compared with type 2 (P = 0.003) and type 3 (P < 0.001). The BC was not able to detect significant differences among the symptom types. Significant differences were found using the TC for the transarterial-only, transvenous anterior-only, and transvenous posterior-only approaches (P < 0.001, P = 0.03, and P = 0.001, respectively). The transvenous posterior and transvenous anterior approach were significantly associated with type 2 and 3 TC, respectively. Excluding direct CCFs, the BC was not related to the treatment approach. No significant differences in the outcomes were found. However, a trend toward a lower occlusion rate for TC type 4 compared with type 3 was observed. CONCLUSION: The TC provided useful information regarding the fistula anatomy and venous hemodynamics, which correlated with the clinical symptoms and treatment strategy.

Clinical Vasospasm After an Extended Endoscopic Endonasal Approach for Recurrent Pituitary Adenoma: Illustrative Case and Systematic Review of the Literature.

BACKGROUND: Cerebral vasospasm causing delayed cerebral ischemia after transsphenoidal surgery is a rare but life-threatening complication. Reports in the literature after extended endoscopic endonasal approach (EEEA) are scarce. Considering the progressive use of this technique during recent years, a better understanding of the potential adverse effects after this procedure is needed. The aim of this report was to systematically analyze the current literature and discuss management and causes for cerebral vasospasm after EEEA surgery. METHODS: We performed a systematic search of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and aimed to discuss relevant risk factors for cerebral vasospasm after extended transsphenoidal surgery. RESULTS: Thirty-four cases of delayed cerebral vasospasm after transsphenoidal surgery were identified. Among these, 4 were operated with an EEEA. We provide an extensive literature review and discuss causes and management of this delayed complication. We further present the case of a young woman who underwent resection for a large suprasellar recurrent pituitary adenoma. Surgery and initial postoperative course were uneventful. On the eighth postoperative day, the patient developed aphasia and brachiofacial paresis. Digital subtraction angiography (DSA) demonstrated cerebral vasospasm, and repeated intra-arterial nimodipine infusion was administrated. The patient recovered completely and was discharged without neurologic deficits. CONCLUSIONS: The threshold for DSA after unexplained neurologic deterioration after extended transsphenoidal surgery should be low, and cerebral vasospasm should be treated early and aggressively. Surgeons performing EEEA need to consider the possibility of this delayed complication.

Magnetic Resonance Imaging correlates of benign and malignant alterations of the spinal bone marrow.

BACKGROUND AND AIM OF THE WORK: Bone marrow (BM) abnormalities in the spine are a common, sometimes unexpected, finding on Magnetic Resonance Imaging (MRI), which is the most sensitive imaging modality to evaluate the marrow, and their interpretation can be difficult for the unexperienced radiologist. In this review, the MRI appearance of normal age-related BM changes, as well as the imaging features of benign and malignant diseases, are presented. DISCUSSION: A large variety of BM signal alterations has been identified and described, including normal variants, BM reconversion,  degenerative changes, infections, spondyloarthritis and osteonecrosis, trauma, neoplastic lesions (both primary or metastatic), post-radiation and chemotherapy sequelae. CONCLUSIONS: Knowledge of normal age-related BM appearance, normal variants and patterns of involvement in focal and diffuse bone diseases is essential, together with clinical and laboratory data, to narrow the list of the possible differential diagnoses. The radiologist should be familiar with these signal changes, as they can sometimes be discovered incidentally. In this context, it is equally important not to attribute pathological significance to benign alterations and to promptly detect signs of malignant diseases.

Postprocedural, midterm, and long-term results of cerebral aneurysms treated with flow-diverter devices: 7-year experience at a single center.

OBJECTIVE Flow diversion has emerged as a viable treatment option for selected intracranial aneurysms and recently has been gaining traction. The aim of this study was to evaluate the safety and effectiveness of flow-diverter devices (FDDs) over a long-term follow-up period. METHODS The authors retrospectively reviewed all cerebral aneurysm cases that had been admitted to the Division of Neurosurgery of the Università degli Studi di Napoli between November 2008 and November 2015 and treated with an FDD. The records of 60 patients (48 females and 12 males) harboring 69 cerebral aneurysms were analyzed. The study end points were angiographic evidence of complete aneurysm occlusion, recanalization rate, occlusion of the parent artery, and clinical and radiological evidence of brain ischemia. The occlusion rate was evaluated according to the O'Kelly-Marotta (OKM) Scale for flow diversion, based on the degree of filling (A, total filling; B, subtotal filling; C, entry remnant; D, no filling). Postprocedural, midterm, and long-term results were strictly analyzed. RESULTS Complete occlusion (OKM D) was achieved in 63 (91%) of 69 aneurysms, partial occlusion (OKM C) in 4 (6%), occlusion of the parent artery in 2 (3%). Intraprocedural technical complications occurred in 3 patients (5%). Postprocedural complications occurred in 6 patients (10%), without neurological deficits. At the 12-month follow-up, 3 patients (5%) experienced asymptomatic cerebral infarction. No further complications were observed at later follow-up evaluations (> 24 months). There were no reports of any delayed aneurysm rupture, subarachnoid or intraparenchymal hemorrhage, ischemic complications, or procedure- or device-related deaths. CONCLUSIONS Endovascular treatment with an FDD is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. In the present study, the authors observed effective and stable aneurysm occlusion, even at the long-term follow-up. Data in this study also suggest that ischemic complications can occur at a later stage, particularly at 12-18 months. On the other hand, no other ischemic or hemorrhagic complications occurred beyond 24 months.

Stent-assisted coiling in ruptured cerebral aneurysms: multi-center experience in acute phase.

INTRODUCTION: The purpose of this study is to report on a multi-center experience of ruptured intracranial aneurysms treated in acute phase with stent-assisted coil embolization, including primary success rates and midterm follow-up results. MATERIALS AND METHODS: Retrospective analysis was performed on a sample of 40 patients (14 men, 26 women, mean age 59.7 years) affected by ruptured saccular aneurysms and treated by stent-assisted coiling in acute phase; double antiplatelet therapy with clopidogrel bisulphate and acetylsalicylic acid was started after the procedure. Angiographic follow-up at 1 year was recorded. RESULTS: 20 % of the aneurysms were located in the posterior circulation, and 85 % presented a wide neck. Mean size of the sac was 7 mm (range 3-22 mm). Complete sac exclusion was obtained in 92.5 % and neck remnant in 7.5 %. The overall complications rate was 15 %. In 7.5 %, stent occlusion occurred intra-procedurally. In 12.5 %, re-bleeding was detected within 3 weeks after the procedure. Ischemic area related to the procedure was observed at follow-up in 7.5 %. Hydrocephalus developed in 15 %. 7.5 % presented with sac re-bleeding between 1 and 5 months after the procedure. In 15 %, the 3-6 months of follow-up revealed aneurysm refilling. 25 % of the patients presented vessel stenosis at the 1-year DSA of control. 33 % of the patients reported sensory-motor deficits. 82.5 % had a favorable outcome (GOS: IV-V), while 17.5 % presented a poor score (GOS: I-III). CONCLUSIONS: Stent-assisted coil embolization is a feasible endovascular treatment option for ruptured intracranial aneurysms, which is difficult to approach with simple coiling; however, neurointerventionalists need to consider a mild increase of post-procedural complications rate.

Mid-term and long-term follow-up of intracranial aneurysms treated by the p64 Flow Modulation Device: a multicenter experience.

BACKGROUND: Experience with the endovascular treatment of cerebral aneurysms using the p64 Flow Modulation Device is still limited. This study discusses the results and complications of this new flow diverter device. METHODS: 40 patients (30 women, 10 men) with 50 cerebral aneurysms treated in six Italian neurointerventional centers with the p64 Flow Modulation Device between April 2013 and September 2015 were retrospectively reviewed. RESULTS: Complete occlusion was obtained in 44/50 aneurysms (88%) and partial occlusion in 3 (6%). In the other three aneurysms (6%), two cases of asymptomatic in-stent thrombosis and one intraprocedural occlusion of the parent vessel occurred. Technical complications were observed in eight procedures (16%). Permanent morbidity due to acute in-stent thrombosis and consequent ischemic stroke occurred in one patient (2.5%). No delayed aneurysm rupture, subarachnoid or intraparenchymal hemorrhage, or ischemic complications occurred and there were no deaths. CONCLUSIONS: Endovascular treatment with the p64 Flow Modulation Device is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. As with other flow diverter devices, we recommend this treatment mainly for large-necked aneurysms of the internal carotid artery siphon. However, endovascular treatment with the p64 device should also be encouraged in difficult cases such as aneurysms of the posterior circulation and beyond the circle of Willis.

Is advanced neuroimaging for neuroradiologists? A systematic review of the scientific literature of the last decade.

INTRODUCTION: To evaluate if advanced neuroimaging research is mainly conducted by imaging specialists, we investigated the number of first authorships by radiologists and non-radiologist scientists in articles published in the field of advanced neuroimaging in the past 10 years. METHODS: Articles in the field of advanced neuroimaging identified in this retrospective bibliometric analysis were divided in four groups, depending on the imaging technique used. For all included studies, educational background of the first authors was recorded (based on available online curriculum vitae) and classified in subgroups, depending on their specialty. Finally, journal impact factors were recorded and comparatively assessed among subgroups as a metric of research quality. RESULTS: A total number of 3831 articles were included in the study. Radiologists accounted as first authors for only 12.8 % of these publications, while 56.9 % of first authors were researchers without a medical degree. Mean impact factor (IF) of journals with non-MD researchers as first authors was significantly higher than the MD subgroup (p < 10-20), while mean IF of journals with radiologists as first authors was significantly lower than articles authored by other MD specialists (p < 10-11). CONCLUSIONS: The majority of the studies in the field of advanced neuroimaging in the last decade is conducted by professional figures other than radiologists, who account for less than the 13 % of the publications. Furthermore, the mean IF value of radiologists-authored articles was the lowest among all subgroups. These results, taken together, should question the radiology community about its future role in the development of advanced neuroimaging.

Hirayama's disease: an Italian single center experience and review of the literature.

BACKGROUND: Hirayama's disease (HD), is a benign, self-limited, motor neuron disease, characterized by asymmetric weakness and atrophy of one or both distal upper extremities. In the present study we report the clinical, electrophysiological and MRI features of a group of Italian patients, with review of the literature. Moreover we propose an optimized MRI protocol for patients with suspected or diagnosed HD in order to make an early diagnosis and a standardized follow up. METHODS: Eight patients with clinical suspicion of Hirayama disease underwent evaluation between January 2007 and November 2013. All patients underwent standard nerve conduction studies (NCS), electromyography (EMG) and motor/sensory evoked potentials (MEP/SEP). Cervical spine MRI studies were conducted with a 1.5 Tesla MRI scanner in neutral and flexion position, including sagittal T1-weighted sequences and sagittal and axial T2-weighted sequences. The following diagnostic features were evaluated: abnormal cervical curvature, localized cervical cord atrophy in the lower tract (C4-C7), presence of cord flattening (CF), intramedullary signal hyperintensity on T2 weighted sequences, anterior shifting of the posterior wall of the cervical dural sac (ASD) and presence of flow voids (EFV) in the posterior epidural space during flexion. RESULTS: All patients complained of weakness in hand muscles as initial symptoms, associated with hand tremor in three of them and abnormal sweating of the hand palm in two of them. No sensory deficits and weakness at lower limbs were reported by any patients. Distal deep tendon reflexes at upper limbs were absent in all patients with the absence of the right tricipital reflex in one of them. Deep tendon reflexes at lower limbs were normal and no signs of pyramidal tract involvement were present. The clinical involvement at onset was unilateral in six patients (three left-sided and three right-sided) and bilateral asymmetric in two of them, with the right side more affected. With the progression of the disease all patients but one experienced weakness and wasting of hand muscles and forearm bilaterally, but still asymmetric. The duration of the progression phase of the disease ranged from eight months to three years. In all patients, NCS and EMG findings were consistent with a spinal metameric disorder involving the C7-T1 myotomes bilaterally; sensory conduction and electrophysiologic features at lower limbs were normal. MEP and SEP were normal and we did not observe the disappearance of the spinal potential during the neck flexion in any of the patients. MRI is the best diagnostic tool in the diagnosis of HD; it can confirm clinical diagnosis and exclude other conditions responsible for the neurological deficits leading to a correct patient management and therapy, limiting arm impairment. On MRI all patients had loss of the normal cervical lordosis (100%). Five patients had loss of attachment of posterior dural sac and anterior dural shift on flexion MRI with presence of flow voids from venous plexus congestion (62.5%); three patients had no anterior dislocation of the dural sac and no epidural vein congestion. Two patients showed localized cord atrophy, one at C5-C6 and the other at C6-C7 level (25%). Three patients had T2 intramedullary hyperintensities (37.5%) and cord flattening (CF) was present in 5 patients of 8 (62.5%). CONCLUSIONS: HD is a rare entity and a self-limited condition, but it has to be early differentiated from other diseases that may determine myelopathy and amyotrophy to establish a correct therapy and limit arm impairment. MRI is very important to confirm the clinical suspect of HD and a standardized MRI protocol using axial and sagittal images in both neutral and flexing position is needed, in order to diagnose and follow up affected patients.