A Damp-and-Push Technique for the Copolymer (Onyx) Embolization of Dural Arteriovenous Fistula

BackgroundCopolymer (Onyx) embolization is an effective treatment for dural arteriovenous fistula (dAVF), however, some dAVFs have multiple, high-flow feeding vessels, resulting in insufficient embolization. For the treatment of such patients, we have developed a novel flow-control technique, the ‘damp-and-push technique’. The purpose of this study was to evaluate the technical efficiency and safety of this technique.MethodsSeven patients who had been diagnosed with intracranial dAVF were treated by transarterial Onyx embolization using the damp-and-push technique between 2016 and 2019. This technique was designed to reduce blood flow to the shunt site using a balloon catheter in the major feeding vessel other than the one injected with Onyx, leading to better Onyx penetration and enabling more controlled embolization of complex dAVFs. Retrospectively collected data were reviewed to assess the occlusion rates and clinical outcomes.ResultsThe dAVF was at a transverse sinus-sigmoid sinus junction in four patients, in the superior sagittal sinus in two, and in the tentorium in one. Five cases were Cognard type Ⅱb and two cases were Cognard type Ⅳ. All the patients were treated by transarterial Onyx injection via the main feeding vessel, combined with flow reduction in the other main feeding vessel using a balloon catheter. Complete occlusion was achieved in six patients and elimination of cerebral venous reflux was achieved in all the patients. There were no immediate or delayed post-interventional complications.ConclusionsTransarterial Onyx embolization of dAVF using the damp-and-push technique is safe and yields a high complete occlusion rate.     

Complete genome sequence analysis of bacterial-flagellum-targeting bacteriophage chi

Bacteriophage chi is a well-known phage that infects pathogens such as E. coli, Salmonella, and Serratia via bacterial flagella. To further understand its host-phage interaction and infection mechanism via host flagella, the genome was completely sequenced and analyzed. The phage genome contains 59,407-bp-length DNA with a GC content of 56.51 %, containing 75 open reading frames (ORFs) with no tRNA genes. Its annotation and functional analysis revealed that chi is evolutionarily very closely related to Enterobacter phage Enc34 and Providencia phage Redjac. However, most of the annotated genes encode hypothetical proteins, indicating that further genomic study of phage chi is required to elucidate the bacterial-flagellum-targeting infection mechanism of phage chi.     

Relative signal intensity on time-of-flight magnetic resonance angiography as a novel indicator of aggressive presentation of intracranial dural arteriovenous fistulas

Asymptomatic dural arteriovenous fistulas (DAVFs) with cortical venous reflux (CVR) are now more commonly encountered. However, patients with an incidental onset may have a less aggressive clinical course. It is desirable to explore methods and indicators to predict the clinical outcomes. This study investigates whether the relative signal intensity (rSI) of the draining vessels on the time-of-flight magnetic resonance angiography is related to clinical behavior in patients with intracranial DAVFs. We retrospectively reviewed 36 intracranial DAVFs. The patients were categorized as those with either aggressive-presentation or non-aggressive-presentation (n = 16 and 20, respectively). The rSIs of the shunt points, affected sinuses, and veins with CVR were compared between the two groups. The two groups were not significantly different in terms of rSIs of the shunt points and affected sinuses (p = 0.37 and 0.41, respectively). However, a significant positive correlation was observed in the rSI of the veins with CVR between the aggressive and non-aggressive behavior groups (p < 0.0001). The rSI of the veins with CVR could serve as a reliable indicator of aggressive behavior in intracranial DAVFs, and its optimal cutoff value was 1.63 with high sensitivity and specificity for predicting aggressive behavior (area under the curve, 0.909).     

The Mediating Effect of Insomnia on the Relationship between Panic Symptoms and Depression in Patients with Panic Disorder

BackgroundThis study aimed to determine if sleep disturbances may mediate the relationship between panic symptoms and depression in patients with panic disorder (PD).MethodsElectronic medical records were retrospectively reviewed for 110 consecutive patients with diagnosed PD in an outpatient clinic between October 2018 and December 2019. Measurements include the PD Severity Scale, Beck Depression Inventory-II (BDI-II) and Insomnia Severity Index (ISI). Statistical analyses were performed to assess any potential relationship between PD, insomnia and depression.ResultsOf the PD patients, 88 (80%) and 89 (80.9%) had comorbid depression (BDI-II ≥ 14) and insomnia (Korean version of the ISI ≥ 8), respectively. In a mediation model using insomnia as the mediating variable, the total effect of panic symptom severity on depression was significant (t = 7.23, P < 0.001). There were significant effects of panic symptoms on insomnia (t = 4.62, P < 0.001) and of insomnia on depression (t = 6.69, P < 0.001). The main effect of panic symptom severity on depression was also significant, after controlling for the effect of insomnia (t = 5.10, P < 0.001), suggesting partial mediation.ConclusionBoth depressive symptoms and insomnia are common in patients with PD and depression was partially mediated by insomnia in these patients. These results suggest that an intervention for insomnia in patients with PD might help prevent the development of depression.     

Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging of the Pancreas: Comparison with Conventional Single-Shot Echo-Planar Imaging

ObjectiveTo investigate the image quality (IQ) and apparent diffusion coefficient (ADC) of reduced field-of-view (FOV) di-ffusion-weighted imaging (DWI) of pancreas in comparison with full FOV DWI.ResultsOn qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm² and 2.81 ± 0.64 at b = 400 s/mm²), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm² and 3.15 ± 0.79 at b = 400 s/mm²), IQ score (8.51 ± 2.05 at b = 0 s/mm² and 8.79 ± 1.60 at b = 400 s/mm²), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm² and 2.56 ± 0.47 at b = 500 s/mm²; lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm² and 2.89 ± 0.86 at b = 500 s/mm²; IQ score, 7.13 ± 1.83 at b = 0 s/mm² and 8.17 ± 1.31 at b = 500 s/mm²; clinical utility, 3.14 ± 0.70) (p < 0.05). Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm² (full FOV DWI, 2.41 ± 0.63) (p < 0.001). On quantitative analysis, there were no significant differences between the 2 DWI sequences in ADCs of various pancreatic lesions and parenchyma (p > 0.05). ADCs of adenocarcinomas (1.061 × 10^-3 mm²/s ± 0.133 at reduced FOV and 1.079 × 10^-3 mm²/s ± 0.135 at full FOV) and neuroendocrine tumors (0.983 × 10^-3 mm²/s ± 0.152 at reduced FOV and 1.004 × 10^-3 mm²/s ± 0.153 at full FOV) were significantly lower than those of parenchyma (1.191 × 10^-3 mm²/s ± 0.125 at reduced FOV and 1.218 × 10^-3 mm²/s ± 0.103 at full FOV) (p < 0.05).ConclusionReduced FOV DWI of the pancreas provides better overall IQ including better anatomic detail, lesion conspicuity and subjective clinical utility.