3D dissimilar-siamese-u-net for hyperdense Middle cerebral artery sign segmentation.

The hyperdense middle cerebral artery sign (HMCAS) representing a thromboembolus has been declared as a vital CT finding for intravascular thrombus in the diagnosis of acute ischemia stroke. Early recognition of HMCAS can assist in patient triage and subsequent thrombolysis or thrombectomy treatment. A total of 624 annotated head non-contrast-enhanced CT (NCCT) image scans were retrospectively collected from multiple public hospitals in Hong Kong. In this study, we present a deep Dissimilar-Siamese-U-Net (DSU-Net) that is able to precisely segment the lesions by integrating Siamese and U-Net architectures. The proposed framework consists of twin sub-networks that allow inputs of left and right hemispheres in head NCCT images separately. The proposed Dissimilar block fully explores the feature representation of the differences between the bilateral hemispheres. Ablation studies were carried out to validate the performance of various components of the proposed DSU-Net. Our findings reveal that the proposed DSU-Net provides a novel approach for HMCAS automatic segmentation and it outperforms the baseline U-Net and many state-of-the-art models for clinical practice.

First case of neurofibromatosis with posterior reversible encephalopathy syndrome showing spinal cord involvement.

Posterior reversible encephalopathy syndrome (PRES) is a well-documented pathology of the brain in systemic upsets. Majority of PRES cases present with edema in the cerebrum, most commonly in the territory of posterior circulation. It has been reported to show spinal cord involvement in a rare subgroup known as PRES with spinal cord involvement (PRES-SCI), with very limited existing literature even in adult patients. Our institution recently encountered a pediatric case with neurofibromatosis type I (NF 1) showing PRES with extensive reversible spinal cord changes. This case illustrates the features of this rare entity in the pediatric group of patients, and is the first reported case in NF 1 patients.

D-dimer level correlation with treatment response in children with venous malformations.

AIM: Localized intravascular coagulopathy is present in children with venous malformations (VMs) as evidenced by elevated D-dimer levels. Few studies have looked into the changes in D-dimer after sclerotherapy and its correlation with treatment outcome and complications. Our study aims to investigate changes in D-dimer in children with VMs undergoing alcohol sclerotherapy. METHODS: A prospective cohort study from 2014 to 2016, which included children (<18years) with VM undergoing alcohol sclerotherapy, was completed. Demographics and lesion characteristics were recorded. Perioperative D-dimer levels were collected 2weeks prior to treatment (baseline) and on postoperative days 1, 2, 5, and 14, respectively. A raised postoperative D-dimer was defined as a peak level of at least 50% increase of baseline D-dimer. Children were followed up with documentation of lesional size at 6months and long-term recurrence beyond 6months of treatment. RESULTS: Eighteen children were identified (10 females, 8 males) with a median follow up of 21months. Overall, 15 patients (83%) had a satisfactory outcome. Baseline D-dimer levels were high in 8 patients (44%). Postoperative D-dimer level was raised in 12 patients irrespective of their baseline levels, with 92% peaking on postoperative day one (n=11). In the elevated D-dimer group, 11 patients had a satisfactory outcome, and 10 patients did not have long-term recurrence. We did not encounter any complications in our cohort. CONCLUSION: Changes in perioperative D-dimer levels may predict early treatment response and long-term recurrence after alcohol sclerotherapy. With a standardized protocol, alcohol sclerotherapy for venous malformation is safe with minimal complications. TYPE OF STUDY: Prognosis study. LEVEL OF EVIDENCE: IV.

Management of the low-flow head and neck vascular malformations in children: the sclerotherapy protocol.

AIM: Image-guided sclerotherapy is becoming the preferred treatment for low-flow vascular malformations in head and neck region. The authors review the management protocol for this condition and evaluate its clinical outcomes. METHODS: Children with low-flow vascular malformations in head and neck region undergoing sclerotherapy from 2010 to 2013 were reviewed. All patients were assessed by pediatric surgeons and interventional radiologists in the multidisciplinary vascular anomalies clinic. Ultrasonography and intravenous contrast enhanced magnetic resonance imaging were performed preoperatively. Under general anesthesia with endotracheal intubation, sclerotherapy were performed with ultrasonographic and fluoroscopic guidance. Sodium tetradecryl sulfate (STS) foam or ethanolamine was used for venous malformation and doxycycline for lymphatic malformations as primary sclerosants, whereas 98% ethanol was reserved as an adjuvant sclerosant in selected cases of repeated procedures. Perioperative dexamethasone 0.2 mg/kg thrice daily was administered to decrease postsclerotherapy swelling and single dose intravenous mannitol 0.5 g/kg was given to minimize thromboembolic complications. Postoperatively, patients were admitted to intensive care unit for mechanical ventilation under deep sedation for airway protection. RESULTS: Overall 13 children (8 male and 5 female) with a mean age of 25 months (range, 2 mo-11 y) underwent a total of 25 sessions of image-guided staged sclerotherapy. There were five venous and eight lymphatic malformations. Location wise there were eight cervical, one lingual, one parotid, one lip, one facial, and one palatal lesions. Six patients had obstructive airway symptoms. Five patients required staged sclerotherapies from two to six sessions. There were no airway and thromboembolic complications. One patient had bleeding while another had recurrent swelling following sclerotherapy for lymphatic malformations and they were treated by aspiration. Significant size reductions of more than 50% volume were achieved in all patients. All patients with obstructive symptoms showed improvement. CONCLUSION: Sclerotherapy is a safe and effective treatment for head and neck vascular malformations in children. Routine perioperative protocol is essential to reduce airway and thromboembolic complications. Size reduction and functional improvement occurred in all patients undergoing sclerotherapy.

Endovascular treatment paradigm of carotid blowout syndrome: review of 8-years experience.

OBJECTIVES: Endovascular treatment is effective in treating carotid blowout syndrome (CBS). We reviewed our experience in addressing CBS over eight years and presented an account of the treatment paradigm and management algorithm. METHOD: All cases of CBS from 2003 to 2010 with endovascular treatment performed in our center were reviewed. 15 CBS in 14 patients were recruited. Based on our management algorithm, treatment regimen was stratified into deconstructive or constructive methods. Their clinical presentations, angiographic features, angiographic and clinical outcomes were reviewed. RESULTS: 10 patients were treated with deconstructive method by means of permanent vessel occlusion (PVO) and 4 patients were treated with constructive method by means of placement of covered stent (n=3) or flow diverting device (n=1). Immediate hemostasis was achieved in all cases. 7 (50%) patients, in whom 5 treated with PVO and 2 with covered stent, had favorable outcomes and survived at a median follow-up period of 4 months (range: 1-84 months). CONCLUSION: Permanent vessel occlusion remains the gold standard of treatment and tends to show a favorable long-term outcome. Off-label use of covered stent and flow-diverting device can produce satisfactory results should balloon occlusion test fail, but long-term follow up would be required for definitive assessment.

Arginase deficiency with new phenotype and a novel mutation: contemporary summary.

In areas without expanded newborn screening, instead of presenting neonatally, patients with arginase deficiency typically present with spastic paraplegia in early childhood. Diagnosis of this rare neurometabolic disease poses the first challenge because it is often misdiagnosed as cerebral palsy during initial stages. We describe arginase deficiency in a 20-year-old woman with spastic paraplegia, progressive dystonia, dementia, peripheral neuropathy, epilepsy, liver cirrhosis, and non-B/non-C hepatocellular carcinoma. A novel homozygous mutation NM_000045.2 (ARG1):c.673del (p.Arg225GlyfsX5) was detected. We suggest that all children presenting with progressive neurodegeneration or spastic paraplegia in the absence of risk factors for cerebral palsy should be screened for inborn errors of metabolism, including arginase deficiency. For monitoring urea cycle defects, noninvasive imaging screening for liver fibrosis and hepatocellular carcinoma can help ensure early detection, with potential treatment implications.

Intracranial aneurysms: midterm outcome of pipeline embolization device--a prospective study in 143 patients with 178 aneurysms.

PURPOSE: To evaluate the midterm clinical and angiographic outcomes after pipeline embolization device (PED) placement for treatment of intracranial aneurysms. MATERIALS AND METHODS: This prospective nonrandomized multicenter study was approved by the review boards of all involved centers; informed consent was obtained. Patients (143 patients, 178 aneurysms) with unruptured saccular or fusiform aneurysms or recurrent aneurysms after previous treatment were included and observed angiographically for up to 18 months and clinically for up to 3 years. Study endpoints included complete aneurysm occlusion; neurologic complications within 30 days and up to 3 years; clinical outcome of cranial nerve palsy after PED placement; angiographic evidence of occlusion or stenosis of parent artery and that of occlusion of covered side branches at 6, 12, and 18 months; and clinical and computed tomographic evidence of perforator infarction. RESULTS: There were five (3.5%) cases of periprocedural death or major stroke (modified Rankin Scale [mRS] > 3) (95% confidence interval [CI]: 1.3%, 8.4%), including two posttreatment delayed ruptures, two intracerebral hemorrhages, and one thromboembolism. Five (3.5%) patients had minor neurologic complications within 30 days (mRS = 1) (95% CI: 1.3%, 8.4%), including transient ischemic attack (n = 2), small cerebral infarction (n = 2), and cranial nerve palsy (n = 1). Beyond 30 days, there was one fatal intracerebral hemorrhage and one transient ischemic attack. Ten of 13 patients (95% CI: 46%, 93.8%) completely recovered from symptoms of cranial nerve palsy within a median of 3.5 months. Angiographic results at 18 months revealed a complete aneurysm occlusion rate of 84% (49 of 58; 95% CI: 72.1%, 92.2%), with no cases of parent artery occlusion, parent artery stenosis (<50%) in three patients, and occlusion of a covered side branch in two cases (posterior communicating arteries). Perforator infarction did not occur. CONCLUSION: PED placement is a reasonably safe and effective treatment for intracranial aneurysms. The treatment is promising for aneurysms of unfavorable morphologic features, such as wide neck, large size, fusiform morphology, incorporation of side branches, and posttreatment recanalization, and should be considered a first choice for treating unruptured aneurysms and recurrent aneurysms after previous treatments. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120422/-/DC1.

Long-term outcome of endovascular reconstruction with the Pipeline embolization device in the management of unruptured dissecting aneurysms of the intracranial vertebral artery.

OBJECT: Use of a flow-diverting device has shown promising short-term results in the management of vertebral artery (VA) dissecting aneurysms, but there is still uncertainty regarding its long-term efficacy and safety. The authors report their initial experience with respect to the potential utility and long-term clinical outcomes of using a flow-diverting device in the treatment of unruptured dissecting VA aneurysms. METHODS: The authors conducted a retrospective review of all cases of unruptured intracranial VA dissecting aneurysms treated at their institution (Tuen Mun Hospital) with a flow-diverting device. They describe the clinical presentations and angiographic features of the cases and report the clinical outcome (with modified Rankin Scale [mRS] scores) at most recent follow-up, as well as results of the latest angiographic assessment, with particular focus on in-stent patency and side-branch occlusion. RESULTS: A total of 4 aneurysms were successfully obliterated by using flow-diverting devices alone. Two devices were deployed in a telescoping fashion in each of 2 aneurysms, whereas only 1 device was inserted in each of the other 2 aneurysms. No periprocedural complication was encountered. No patient showed any angiographic evidence of recurrence, in-stent thrombosis, or side-branch occlusion in angiographic reassessment at a mean of 22 months after treatment (range 18-24 months). As of the most recent clinical follow-up (mean 30 months after treatment, range 24-37 months), all patients had favorable outcomes (mRS Score 0). CONCLUSIONS: Reconstruction using a flow-diverting device is an attractive alternative in definitive treatment of dissecting VA aneurysms, demonstrating favorable long-term clinical and angiographic outcomes and the ability to maintain parent artery and side-branch patency. It is particularly useful in cases with eloquent side-branch or dominant VA involvement.

Forward shifting of posterior dural sac during flexion cervical magnetic resonance imaging in Hirayama disease: an initial study on normal subjects compared to patients with Hirayama disease.

OBJECTIVE: Forward shifting of the posterior cervical dural sac is the most important sign in diagnosing Hirayama disease but can also be seen in normal subjects, causing potential diagnostic dilemma. We aim to explore the degree of forward displacement of posterior dural sac in normal subjects compared to that with Hirayama disease. MATERIALS AND METHODS: 50 healthy male teenagers and 3 patients with Hirayama disease were recruited into the control group and patient group, respectively. MR imaging of the cervical spine was performed in both neutral and flexion positions for all subjects, with the following parameters measured: maximal distance of forward shifting of posterior dural sac, dimension of dural sac and spinal cord. RESULTS: Forward shifting of the posterior cervical dural sac was depicted in 46% of normal subjects upon flexion position but without associated cord compression due to intrinsic expansion of the spinal canal volume. This intrinsic compensatory mechanism was inadequate in diseased patients leading to cord compression with significant increment in ratio of anteroposterior diameter of forward displacement of posterior dural wall/anteroposterior diameter of spinal canal ("x/y"), and decrement in ratio of anteroposterior diameter of spinal cord/perpendicular transverse diameter of spinal cord ("a/b"). CONCLUSION: Depicting of forward shifting of posterior dural sac alone on flexion position cannot reliably diagnose Hirayama disease, which should be established only if there is forward shifting of posterior dural sac, plus increased ratio of x/y and decreased ratio of a/b on flexion position from associated mass effect on the spinal cord.

Immunoablative cyclophosphamide for refractory lupus-related neuromyelitis optica.

Neuromyelitis optica (NMO), or Devic's disease, is an aggressive inflammatory disease of the central nervous system that predominantly affects the optic nerves and the spinal cord. The association with other systemic autoimmune diseases and the discovery of the specific biomarker, NMO-immunoglobulin G (IgG), suggests that NMO is autoimmune in origin. The prognosis of NMO is grave, especially in those patients with early and recurrent relapses. We describe successful use of immunoablative cyclophosphamide in halting relapses in a patient with systemic lupus erythematosus-associated NMO who was unresponsive to high-dose oral and intravenous corticosteroids, intravenous immunoglobulin, mycophenolate mofetil, tacrolimus, low-dose daily oral cyclophosphamide and rituximab.

Femoral facial syndrome with bilateral agenesis of femora and preaxial polydactyly of the feet in a Chinese stillborn.

A female Chinese stillborn with clinical characteristics of femoral facial syndrome is described. Apart from the typical facial features of the syndrome like short nose with broad tip, up-slanting palpebral fissures, cleft lip and cleft palate, micrognathia, and bilateral hypoplastic and malformed pinnae, the case had two rare findings, complete absence of both femora, and preaxial polydactyly in the feet. The combination of these two findings in a single patient had not been reported before. This report also reiterates the rare association between preaxial polydactyly and the femoral facial syndrome.

Haemodialysis catheter-related right transverse cervical artery pseudoaneurysm and treatment by coil embolization.

In patients with end-stage renal disease, temporary placement of venous catheters for haemodialysis (HD) is often necessary, and the right internal jugular (RIJ) vein is the usual preferred site of HD catheter placement. We report here a patient who experienced complications because of the development of a pseudoaneurysm of the transverse cervical artery following an apparently uneventful RIJ vein cannulation for temporary HD, using the blind landmark-guided technique. This is a rare complication of RIJ vein cannulation and HD catheter placement. The pseudoaneurysm presented 3 weeks after the procedure and was diagnosed by using colour-Doppler ultrasound, followed by an angiogram, and it was successfully occluded using endovascular coil embolization.