Comparison of two 2-D numerical models for snow avalanche simulation.

Snow avalanches are gravitational processes characterised by the rapid movement of a snow mass, threatening inhabitants and damaging infrastructure in mountain areas. Such phenomena are complex events, and for this reason, different numerical models have been developed to reproduce their dynamics over a given topography. In this study, we focus on the two-dimensional numerical simulation tools RAMMS::AVALANCHE and FLO-2D, aiming to compare their performance in predicting the deposition area of snow avalanches. We also aim to assess the employment of the FLO-2D simulation model, normally used in water flood or mud/debris flow simulations, in predicting the motion of snow avalanches. For this purpose, two well-documented avalanche events that occurred in the Province of Bolzano (IT) were analyzed (Knollgraben, Pichler Erschbaum avalanches). The deposition area of each case study was simulated with both models through back-analysis processes. The simulation results were evaluated primarily by comparing the simulated deposition area with the observed one through statistical indices. Subsequently, the maximum flow depth, velocity and deposition depth were also compared between the simulation results. The results showed that RAMMS::AVALANCHE generally reproduced the observed deposits better compared to FLO-2D simulation. FLO-2D provided suitable results for wet and dry snow avalanches after a meticulous calibration of the rheological parameters, since they are not those typically considered in avalanche rheology studies. The results showed that FLO-2D can be used to study the propagation of snow avalanches and could also be adopted by practitioners to define hazard areas, expanding its field of application.

Sex life and low back pain: The impact of intradiscal ozone therapy in patients with herniated lumbar disc.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To assess the improvement of sexual impairment after percutaneous intradiscal ozone therapy in patients complaining of low back pain (LBP) due to lumbar disc herniation. METHODS: Between January 2018 and June 2021, 157 consecutive imaging-guided percutaneous intradiscal ozone therapies were performed on 122 patients with LBP and/or sciatic pain due to lumbar disc herniation. Oswestry Disability Index (ODI) was administered before the treatment and at 1-month and 3-month follow-ups and the ODI Section 8 (ODI-8/sex life) values were retrospectively reviewed to evaluate the improvement of sexual impairment and disability. RESULTS: Mean age of patients was 54.63 ± 12.40. Technical success was achieved in all cases (157/157). Clinical success was registered in 61.97% (88/142) of patients at 1-month follow-up and in 82.69% (116/142) at 3-month follow-up. The mean ODI-8/sex life was 3.73 ± 1.29 before the procedure, 1.71 ± 1.37 at 1-month follow up and 0.44 ± 0.63 at 3-month follow-up. Compared to older patients, subjects under 50 years showed a significantly slower recovery of sexual impairment (p = 0.003). The treated levels were L3-L4, L4-L5, and L5-S1 in 4, 116, and 37 patients, respectively. Patients with L3-L4 disc herniation showed less sexual disability at presentation, with a significantly faster improvement of sexual life (p = 0.03). CONCLUSIONS: Percutaneous intradiscal ozone therapy is highly effective in reducing sexual impairment due to lumbar disc herniation, and the improvement is faster in older patients and in the case of L3-L4 disc involvement.

Vasari Scoring System in Discerning between Different Degrees of Glioma and IDH Status Prediction: A Possible Machine Learning Application?

(1) The aim of our study is to evaluate the capacity of the Visually AcceSAble Rembrandt Images (VASARI) scoring system in discerning between the different degrees of glioma and Isocitrate Dehydrogenase (IDH) status predictions, with a possible application in machine learning. (2) A retrospective study was conducted on 126 patients with gliomas (M/F = 75/51; mean age: 55.30), from which we obtained their histological grade and molecular status. Each patient was analyzed with all 25 features of VASARI, blinded by two residents and three neuroradiologists. The interobserver agreement was assessed. A statistical analysis was conducted to evaluate the distribution of the observations using a box plot and a bar plot. We then performed univariate and multivariate logistic regressions and a Wald test. We also calculated the odds ratios and confidence intervals for each variable and the evaluation matrices with receiver operating characteristic (ROC) curves in order to identify cut-off values that are predictive of a diagnosis. Finally, we did the Pearson correlation test to see if the variables grade and IDH were correlated. (3) An excellent ICC estimate was obtained. For the grade and IDH status prediction, there were statistically significant results by evaluation of the degree of post-contrast impregnation (F4) and the percentage of impregnated area (F5), not impregnated area (F6), and necrotic (F7) tissue. These models showed good performances according to the area under the curve (AUC) values (>70%). (4) Specific MRI features can be used to predict the grade and IDH status of gliomas, with important prognostic implications. The standardization and improvement of these data (aim: AUC > 80%) can be used for programming machine learning software.

Neurological manifestations of COVID-19: a retrospective observational study based on 1060 patients with a narrative review.

BACKGROUND: In the past two decades, three coronavirus epidemics have been reported. Coronavirus disease 2019 (COVID-19) is caused by a severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2). In most patients, the disease is characterized by interstitial pneumonia, but features can affect other organs. PURPOSE: To document the radiological features of the patients and to perform a narrative review of the literature. MATERIAL AND METHODS: We conducted a retrospective, single-center study on 1060 consecutive hospitalized patients with COVID-19 at our institution. According to the inclusion criteria, we selected patients to be studied in more radiological detail. All images were obtained as per standard of care protocols. We performed a statistic analysis to describe radiological features. We then presented a systematic review of the main and conventional neuroimaging findings in COVID-19. RESULTS: Of 1060 patients hospitalized for COVID-19 disease, 15% (159) met the eligibility criteria. Of these, 16 (10%) did not undergo radiological examinations for various reasons, while 143 (90%) were examined. Of these 143 patients, 48 (33.6%) had positive neuroimaging. We found that the most frequent pathology was acute ischemic stroke (n=16, 33.3%). Much less frequent were Guillain-Barre syndrome (n=9, 18.8%), cerebral venous thrombosis (n=7, 14.6%), encephalitis or myelitis (n=6, 12.5%), intracranial hemorrhage and posterior hemorrhagic encephalopathy syndrome (n=4, 8.3%), exacerbation of multiple sclerosis (n=4, 8.3%), and Miller-Fisher syndrome (n=2, 4.2%). CONCLUSION: Our data are coherent with the published literature. Knowledge of these patterns will make clinicians consider COVID-19 infection when unexplained neurological findings are encountered.

The Diagnostic Performance of Multi-Detector Computed Tomography (MDCT) in Depiction of Acute Spondylodiscitis in an Emergency Department.

BACKGROUND: The diagnosis of acute spondylodiscitis can be very difficult because clinical onset symptoms are highly variable. The reference examination is MRI, but very often the first diagnostic investigation performed is CT, given its high availability in the acute setting. CT allows rapid evaluation of other alternative diagnoses (e.g., fractures), but scarce literature is available to evaluate the accuracy of CT, and in particular of multi-detector computed tomography (MDCT), in the diagnosis of suspected spondylodiscitis. The aim of our study was to establish MDCT accuracy and how this diagnostic method could help doctors in the depiction of acute spondylodiscitis in an emergency situation by comparing the diagnostic performance of MDCT with MRI, which is the gold standard. METHODS: We searched our radiological archive for all MRI examinations of patients who had been studied for a suspicion of acute spondylodiscitis in the period between January 2017 and January 2021 (n = 162). We included only patients who had undergone MDCT examination prior to MRI examination (n = 25). The overall diagnostic value of MDCT was estimated, using MRI as the gold standard. In particular, the aim of our study was to clarify the effectiveness of CT in radiological cases that require immediate intervention (stage of complications). Therefore, the radiologist, faced with a negative CT finding, can suggest an elective (not urgent) MRI with relative serenity and without therapeutic delays. RESULTS: MDCT allowed identification of the presence of acute spondylodiscitis in 13 of 25 patients. Specificity and positive predictive value were 100% for MDCT, while sensitivity and negative predictive value were 68% and 50%, respectively, achieving an overall accuracy of 76%. In addition, MDCT allowed the identification of paravertebral abscesses (92%), fairly pathognomonic lesions of spondylodiscitis pathology. CONCLUSIONS: The MDCT allows identification of the presence of acute spondylodiscitis in the Emergency Department (ED) with a satisfactory accuracy. In the case of a positive CT examination, this allows therapy to be started immediately and reduces complications. However, we suggest performing an elective MRI examination in negative cases in which pathological findings are hard to diagnose with CT alone.

COVID-19 and low back pain: previous infections lengthen recovery time after intradiscal ozone therapy in patients with herniated lumbar disc.

PURPOSE: To assess and compare the clinical effectiveness of percutaneous intradiscal ozone therapy in patients affected by lumbar disc herniation, with and without history of COVID-19 infection. MATERIALS AND METHODS: After the rising of COVID-19 pandemics in Italy, 47 consecutive percutaneous intradiscal ozone therapies were performed on patients with low back pain and/or sciatic pain due to lumbar disc herniation. Among these, 19 had suffered from COVID-19 and successively recovered with no residual symptoms, while the remaining 28 had not previously been affected by COVID-19 and were not convalescent. Oswestry Disability Index (ODI) was administered before the treatment and at 1-month and 3-month follow-up in order to assess the clinical outcome. RESULTS: The two groups were similar in terms of patient age (p-value 0.54), treated levels (p-value 0.26) and pre-procedure ODI (p-value 0.33). Technical success was achieved in all cases. In patients previously affected by COVID-19, mean ODI decrease was 11.58 ± 9.51 (35.72%) at 1-month follow-up and 20.63 ± 9.87 (63.63%) at 3-month follow-up. In patients never affected by COVID-19, mean ODI decrease was 20.93 ± 10.53 (58.73%) at 1-month follow-up and 22.07 ± 11.36 (61.92%) at 3-month follow-up. Eventually, clinical success was registered in 84.21% (16/19) of patients with history of COVID-19 infection and in 85.71% (24/28) of patients with no history of COVID-19 infection. No major complication was registered. CONCLUSIONS: In case of lumbar disc herniation treated with percutaneous intradiscal ozone therapy, patients previously affected by COVID-19 showed a significantly longer recovery time.

Radiation exposure and clinical outcome in patients undergoing percutaneous intradiscal ozone therapy for disc herniation: Fluoroscopic versus conventional CT guidance.

PURPOSE: To compare technical success, clinical success, complications and radiation dose for percutaneous intradiscal ozone therapy in patients with lumbar disc herniation using fluoroscopic guidance versus conventional computed tomography (CT) guidance. MATERIALS AND METHODS: Between March 2018and March 2021, 124consecutive percutaneous intradiscal ozone therapies wereperformedon111 patients with low back pain (LBP) and/or sciatic pain due to lumbar disc herniation, using fluoroscopic or conventional CT guidance, respectively in 53 and 58 herniated lumbar discs, with at least 1-month follow up. Dose area product (DAP) and dose length product (DLP) were recorded respectively for fluoroscopy and CT, and converted to effective dose (ED). RESULTS: Fluoroscopic and CT groups were similar in terms of patient age (p-value 0.39), patient weight (p-value 0.49) and pre-procedure Oswestry Disability Index (ODI, p-value 0.94). Technical success was achieved in all cases. Clinical success was obtained in 83.02% (44/53) patients in fluoroscopic group and 79.31% (46/58) in CT group. Mean DAP was 11.63Gy*cm2 (range 5.42-21.61). Mean DLP was 632.49mGy-cm (range 151.51-1699). ED was significantly lower in the fluoroscopic group compared toCT group (0.34 vs. 5.53mSv, p = 0.0119). No major complication was registered. Minor complications were observed in 4 cases (2 in fluoroscopic group; 2 in CT group). CONCLUSIONS: Compared to conventional CT guidance, fluoroscopic guidance for percutaneous intradiscal ozone therapy in patients with lumbar disc herniation shows similar technical and clinical success rates, with lower radiation dose. This technique helps sparing dose exposure to patients.

Intradiscal ozone therapy: fluoroscopic guidance reduces operative time in comparison with CT guidance in patients with lumbar disc herniation.

PURPOSE: To compare clinical success and operative time for percutaneous intradiscal ozone therapy in patients with lumbar disc herniation using fluoroscopic guidance versus computed tomography (CT). MATERIALS AND METHODS: During the year 2019, 68 percutaneous single-level intradiscal ozone therapies were performed on patients complaining of low back pain and/or sciatica due to lumbar disc herniation, using fluoroscopic or conventional CT guidance, respectively, in 35 and 32 herniated lumbar discs, with at least 1-month follow-up. Oswestry Disability Index (ODI) was used to assess clinical outcome. Total room utilization time and procedure operative time were recorded for both fluoroscopy and CT guidance. RESULTS: Fluoroscopy and CT groups were similar in terms of patient age (p value 0.45) and pre-procedure ODI (p value 0.64). Clinical success was obtained in 87.50% (28/32) patients in fluoroscopic group and 83.33% (30/36) in CT group. Mean total room utilization time was significantly longer for CT guidance (31.38 vs. 50.67 min, p < 0.0001), as well as the procedure operative time (15.94 vs. 27.61 min, p < 0.0001). CONCLUSIONS: Compared to conventional CT guidance, fluoroscopic guidance for percutaneous intradiscal ozone therapy in patients with lumbar disc herniation shows similar clinical success rates at 1-month follow-up, with decreased room utilization time and procedure operative time that implies less time consumption for medical and paramedical operative team.

Simulating the effect of check dam collapse in a debris-flow channel.

Sequences of erosion control/consolidation check dams are the most widespread channel countermeasure in the European Alps. Some of them were built in the past based on ancient technologies. Nowadays they may not be fully adequate to mitigate the debris-flow/flood events that are becoming more frequent and intense. Consequently, there is the remote possibility that they could fail with disastrous consequences as observed in some cases. A reliable methodology to reproduce the effect of check dam collapse has not yet proposed. Therefore the aim of this study is to define a procedure to simulate the effect of check dam collapse in a debris-flow event. In this study we analysed the catastrophic debris flow occurred in the Rotian channel (Italian Alps) during which a series of check dams collapsed magnifying the event and causing severe damages. With the aid of field data we reconstructed the event and used the simulation tool r.avaflow to reproduce the debris flow. We then defined three scenarios to simulate the event: (A) debris-flow propagation over an erodible channel; (B) propagation on a rigid channel bed combined with the release of impulsive masses to isolate the analysis of the effect of check dam collapse; (C) a combination of the previous scenarios. The simulation performance was assessed analysing the pre- and post-event LiDAR surveys. Results showed that the C scenario accurately reproduced the observed debris-flow erosion pattern. In particular, we found out that most of the entrained debris volume derived from bed erosion rather than the sediment retained by check dams. The adopted method, which composes the contribution of bed erosion and check dam collapse, could be of particular relevance for residual risk estimation when mitigation structures are old and may fail with potential disastrous consequences.

Intracranial Hemorrhage from Dural Arteriovenous Fistulas: What Can We Find with CT Angiography?

(1) Background: Dural arteriovenous fistulas (DAVF) represent a rare acquired intracranial vascular malformation, with a variety of clinical signs and symptoms, which make their diagnosis difficult. Intracranial hemorrhage is one of the most serious clinical manifestations. In this paper the authors' goal was to verify the accuracy and utility of contrast-enhanced brain CT angiography (CTA) for the identification and the characterization of dural arteriovenous fistulas (DAVFs) in patients who presented with brain hemorrhage compared to 3D digital subtraction angiography (3D DSA); (2) a retrospective study of 26 patients with DAVFs who presented with intracranial hemorrhage to our institution was performed. The information reviewed included clinical presentation, location and size of hemorrhage, brain CTA and 3D DSA findings; (3) results: 61% (16/26) of DAVFs were identified by CTA. The vast majority of patients were male (69%, 18/26) and the most common presenting symptom was sudden onset headache. All DAVFs had cortical venous drainage and about one-third were associated with a venous varix. The most common location was tentorial (73%, 19/26); (4) conclusions: CTA can represent a valid alternative diagnostic method to 3D DSA for the study of DAVF in the initial and preliminary diagnostic approach, especially in emergency situations. In fact, it represents a fast, inexpensive, non-invasive and above all, easily accessible and available diagnostic technique, unlike DSA or MRI, allowing to provide information necessary for the identification, classification and treatment planning of DAVFs.

A Rare Case of Cerebral Venous Thrombosis and Disseminated Intravascular Coagulation Temporally Associated to the COVID-19 Vaccine Administration.

Globally, at the time of writing (20 March 2021), 121.759.109 confirmed COVID-19 cases have been reported to the WHO, including 2.690.731 deaths. Globally, on 18 March 2021, a total of 364.184.603 vaccine doses have been administered. In Italy, 3.306.711 confirmed COVID-19 cases with 103.855 deaths have been reported to WHO. In Italy, on 9 March 2021, a total of 6.634.450 vaccine doses have been administered. On 15 March 2021, Italian Medicines Agency (AIFA) decided to temporarily suspend the use of the AstraZeneca COVID-19 vaccine throughout the country as a precaution, pending the rulings of the European Medicines Agency (EMA). This decision was taken in line with similar measures adopted by other European countries due to the death of vaccinated people. On 18 March 2021, EMA's safety committee concluded its preliminary review about thromboembolic events in people vaccinated with COVID-19 Vaccine AstraZeneca at its extraordinary meeting, confirming the benefits of the vaccine continue to outweigh the risk of side effects, however, the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, i.e., low levels of blood platelets with or without bleeding, including rare cases of cerebral venous thrombosis (CVT). We report the case of a 54-year-old woman who developed disseminated intravascular coagulation (DIC) with multi-district thrombosis 12 days after the AstraZeneca COVID-19 vaccine administration. A brain computed tomography (CT) scan showed multiple subacute intra-axial hemorrhages in atypical locations, including the right frontal and the temporal lobes. A plain old balloon angioplasty (POBA) of the right coronary artery was performed, without stent implantation, with restoration of distal flow, but with persistence of extensive thrombosis of the vessel. A successive thorax angio-CT added the findings of multiple contrast filling defects with multi-vessel involvement: at the level of the left upper lobe segmental branches, of left interlobar artery, of the right middle lobe segmental branches and of the right interlobar artery. A brain magnetic resonance imaging (MRI) in the same day showed the presence of an acute basilar thrombosis associated with the superior sagittal sinus thrombosis. An abdomen angio-CT showed filling defects at the level of left portal branch and at the level of right suprahepatic vein. Bilaterally, it was adrenal hemorrhage and blood in the pelvis. An evaluation of coagulation factors did not show genetic alterations so as the nasopharyngeal swab ruled out a COVID-19 infection. The patient died after 5 days of hospitalization in intensive care.

Relationship Between Gender and the Effectiveness of Montelukast: An Italian/Danish Register-Based Retrospective Cohort Study.

Rationale: Gender-related differences in asthma prevalence, pathophysiology and clinical features induced by sex steroids have been investigated, however, how gender influences response to asthma treatments in routine clinical practice have not yet been elucidated fully. This aspect is crucial for montelukast considering the jeopardization of asthmatic patients that benefit from this treatment and the existence of evidence of gender differences in leukotriene levels. Therefore, to fulfill this medical need, we investigated the role of gender on a set of montelukast' effectiveness surrogates in adults and pediatric patients with asthma. Methods: The study settings were Napoli 2 Local Health Unit (southern Italy) and the entire Danish territory. The study population was composed of adult and pediatric patients with asthma. Cumulative incidence curves, unadjusted and adjusted Cox regression were used as statistical models to compare aforementioned outcomes between genders. Results: Adult Italian male users of montelukast had a statistically lower persistence in montelukast treatment compared to female users. In the adjusted analyses, they had a higher hazard of montelukast' withdrawal (Hazard Ratio [HR] 1.07; 95% Confidence Interval [CI] 1.01-1.14), add-on/switch to a long-term treatment for asthma following montelukast withdrawal (HR 1.72; 95%CI 1.39-2.12), and rescue therapy with short-acting ß2 agonist (HR 1.24; 95%CI 1.04-1.47). In the adult Danish cohort, we also found that male users had higher a hazard of rescue therapy with oral corticosteroids (HR 1.10; 95%CI 1.04-1.16). In the pediatric cohorts, no statistically significant differences were observed between genders for aforementioned outcomes. Conclusions: In adults, male gender was associated with increased hazards of montelukast discontinuation, add-on/switch to a long-term treatment for asthma following montelukast withdrawal, and rescue therapy with oral corticosteroids or short-acting ß2 agonist when compared to the female gender. As expected, these associations were reversed or absent in pediatric patients.

Magnetic resonance imaging in the pre-operative evaluation of obstructive epiphora: true-FISP and VIBE vs gadolinium.

PURPOSE: To assess unenhanced magnetic resonance imaging (MRI) in the preoperative evaluation of obstructive epiphora in patients undergoing dacryocystorhinostomy (DCR) and in particular, to evaluate the efficacy of this technique in the detection of the exact level of obstruction occurring in the naso-lachrymal duct (NLD). The correct identification and characterization of the NLD and its obstructions lead to a more effective surgery, preventing recurrent dacryocystitis after the surgical treatment. METHODS: From January 2009 to December 2014, 127 obstructive epiphoras were diagnosed and treated in 127 patients (35 M, 92 F; mean age 60.7 ± 7.48 years, range 42-75 years) with endoscopic DCR, in a IRB-approved protocol. To precisely define the morphology of the NLD and the site of obstruction, some of these patients (67/127) underwent unenhanced 1.5-T MR with TrueFISP and VIBE sequences, while the remaining (60/127) underwent Gadolinium-enhanced 1.5-T MR. Afterwards, surgery checked the real site of obstruction in both groups of patients (enhanced and unenhanced MR), with surgical outcomes matched with previous MR reports. RESULTS: In all cases, unenhanced MRI was able to detect the exact site of obstruction along the NLD, allowing a correct planning of surgical endoscopic procedures. On the contrary, enhanced MRI wrongly diagnosed six patients with proximal stenosis (6/60, 10.0%) as intermediate NLD obstruction. Unenhanced MRI was found to be more accurate than enhanced MRI with a statistical significant difference (p value = 0.0256) and obviously cheaper and easier to perform. All imaging reports were verified with surgery. The correct identification of the level of obstruction allowed successful surgery in around 73% (93/127) of patients, who had no recurrence during 6-month follow-up. CONCLUSION: In patients with epiphora, unenhanced MR showed to be highly reliable and even more effective than enhanced MR in the preoperative characterization of NLD stenosis, with no need of performing complex, time-wasting and expensive procedures for the administration of topical contrast media.