Project description:ObjectiveTo determine the usefulness of Silent MR angiography (MRA) for evaluating intracranial aneurysms treated with stent-assisted coil embolization.Materials and methodsNinety-nine patients (101 aneurysms) treated with stent-assisted coil embolization (Neuroform atlas, 71 cases; Enterprise, 17; LVIS Jr, 9; and Solitaire AB, 4 cases) underwent time-of-flight (TOF) MRA and Silent MRA in the same session using a 3T MRI system within 24 hours of embolization. Two radiologists independently interpreted both MRA images retrospectively and rated the image quality using a 5-point Likert scale. The image quality and diagnostic accuracy of the two modalities in the detection of aneurysm occlusion were further compared based on the stent design and the site of aneurysm.ResultsThe average image quality scores of the Silent MRA and TOF MRA were 4.38 ± 0.83 and 2.78 ± 1.04, respectively (p < 0.001), with an almost perfect interobserver agreement. Silent MRA had a significantly higher image quality score than TOF MRA at the distal internal carotid artery (n = 57, 4.25 ± 0.91 vs. 3.05 ± 1.16, p < 0.001), middle cerebral artery (n = 21, 4.57 ± 0.75 vs. 2.19 ± 0.68, p < 0.001), anterior cerebral artery (n = 13, 4.54 ± 0.66 vs. 2.46 ± 0.66, p < 0.001), and posterior circulation artery (n = 10, 4.50 ± 0.71 vs. 2.90 ± 0.74, p = 0.013). Silent MRA had superior image quality score to TOF MRA in the stented arteries when using Neuroform atlas (4.66 ± 0.53 vs. 3.21 ± 0.84, p < 0.001), Enterprise (3.29 ± 1.59 vs. 1.59 ± 0.51, p = 0.003), LVIS Jr (4.33 ± 1.89 vs. 1.89 ± 0.78, p = 0.033), and Solitaire AB stents (4.00 ± 2.25 vs. 2.25 ± 0.96, p = 0.356). The interpretation of the status of aneurysm occlusion exhibited significantly higher sensitivity with Silent MRA than with TOF MRA when using the Neuroform Atlas stent (96.4% vs. 14.3%, respectively, p < 0.001) and LVIS Jr stent (100% vs. 20%, respectively, p = 0.046).ConclusionSilent MRA can be useful to evaluate aneurysms treated with stent-assisted coil embolization, regardless of the aneurysm location and type of stent used.
Project description:MR angiography is proposed as a safer and less expensive alternative to the reference standard, DSA, in the follow-up of intracranial aneurysms treated with endovascular coil occlusion. We performed a systematic review and meta-analysis to evaluate the accuracy of TOF-MRA and contrast-enhanced MRA in detecting residual flow in the follow-up of coiled intracranial aneurysms. Literature was reviewed through the PubMed, Cochrane, and EMBASE data bases. In comparison with DSA, the sensitivity of TOF-MRA was 86% (95% CI: 82-89%), with a specificity of 84% (95% CI: 81-88%), for the detection of any recurrent flow. For contrast-enhanced MRA, the sensitivity and specificity were 86% (95% CI: 82-89%) and 89% (95% CI: 85-92%), respectively. Both TOF-MRA and contrast-enhanced MRA are shown to be highly accurate for detection of any recanalization in intracranial aneurysms treated with endovascular coil occlusion.
Project description:IntroductionThe aim of this work is to compare in a retrospective study, the radiological results of three series of different total knee replacements performed using Orthopilot computer-based alignment system (Group A, 31 patients), a totally intramedullary alignment system (Group B, 34 patients) and a totally extramedullary alignment system (Group C, 32 patients).Materials and methodsAt a medium follow-up of 15 years, all patients underwent call interview for clinical update. Of the 115 patients initially enrolled in the study, only 97 were available for radiological assessment. Both standing long-leg antero-posterior radiographs and lateral radiographs of the knee had been taken for every patient at 1 year-follow-up and at the last follow-up.ResultsAt the last follow-up, the mean hip-knee-ankle angle (HKA) was 179.1° (range: 176°-184°) for group A, 178.6° (range: 173°-186°) for group B and 177.8° (range: 172°-186°) for group C with no statistically significant difference among the 3 groups. The mean frontal femoral component angle (FFC) was 90.5° (range: 87°-94°) for group A, 91.05° (range: 85°-95°) for group B and 91.19° (range: 85°-96°) for group C and there was no statistically significant difference among the three groups. The mean frontal tibial component angle (FTC) was 89.9° (range: 83°-97°) for group A, 90.6° (range: 87°-95°) for group B and 90.8° (range: 86°-95°) for group C and there was no statistically significant difference among the three groups. The mean tibial component inclination in the sagittal plane was 1° (range: 3°-0°) for group A, 3.6° (range: 7°-0°) for group B and 3.1° (range: 6°-0°) for group C.Discussion and conclusionOur results demonstrated statistically significant differences between computer-assisted and extramedullary group, in favour of navigated group in terms of implant position and mechanical alignment. Computer-assisted group showed superior but not statistically significant differences compared to intramedullary alignment system in terms of implant position and mechanical alignment. We advocate the use of computer-assisted system routinely in total knee replacement. As an alternative, we suggest the use of intramedullary system.
Project description:IntroductionAngiography is the standard follow-up modality for treated aneurysms with the Woven EndoBridge (WEB), and magnetic resonance angiography (MRA) is useful for extended follow-up. We present the results of WEB-treated aneurysms with angiographic follow-up at three months and at least 18 months' 3T MRA follow-up.Materials and methodsIncluded were 52 patients with 53 aneurysms treated with the WEB between February 2015 and July 2016. There were 29 women and 23 men with a mean age of 60 years (median 62, range 23-76). Mean aneurysm size was 6.2 mm (median 6, range 3-16 mm).Results3T MRA follow-up was mean 19.6 months (median 18, range 18-36 months). One patient had an aneurysm remnant at three-month angiography that was additionally coiled and with stable complete occlusion at 18 months' 3T MRA follow-up. At three-month follow-up angiography, 44 aneurysms were completely occluded and eight had a neck remnant. At latest 3T MRA, stable complete occlusion was present in 43 aneurysms and stable neck remnant in eight. One posterior cerebral artery (PCA) dissection aneurysm was stable at three and six months but was enlarged and reopened at 18 months, confirmed with angiography. Focal signal loss by the proximal marker of the WEB was apparent in four patients without compromising diagnostic evaluation.ConclusionWEB-treated aneurysms with adequate occlusion at three-month angiography remained stable during serial 3T MRA follow-up of 18-36 months. One PCA aneurysm reopened during the 6- to 18-month interval. Once the WEB-treated aneurysm is adequately occluded in the short term, later reopening is uncommon.
Project description:Brain aneurysm detection in Time-Of-Flight Magnetic Resonance Angiography (TOF-MRA) has undergone drastic improvements with the advent of Deep Learning (DL). However, performances of supervised DL models heavily rely on the quantity of labeled samples, which are extremely costly to obtain. Here, we present a DL model for aneurysm detection that overcomes the issue with "weak" labels: oversized annotations which are considerably faster to create. Our weak labels resulted to be four times faster to generate than their voxel-wise counterparts. In addition, our model leverages prior anatomical knowledge by focusing only on plausible locations for aneurysm occurrence. We first train and evaluate our model through cross-validation on an in-house TOF-MRA dataset comprising 284 subjects (170 females / 127 healthy controls / 157 patients with 198 aneurysms). On this dataset, our best model achieved a sensitivity of 83%, with False Positive (FP) rate of 0.8 per patient. To assess model generalizability, we then participated in a challenge for aneurysm detection with TOF-MRA data (93 patients, 20 controls, 125 aneurysms). On the public challenge, sensitivity was 68% (FP rate = 2.5), ranking 4th/18 on the open leaderboard. We found no significant difference in sensitivity between aneurysm risk-of-rupture groups (p = 0.75), locations (p = 0.72), or sizes (p = 0.15). Data, code and model weights are released under permissive licenses. We demonstrate that weak labels and anatomical knowledge can alleviate the necessity for prohibitively expensive voxel-wise annotations.
Project description:The purpose of this study is to evaluate the effect of artificial intelligence systems used during colonoscopy on the detection of precancerous polyps in the colon.
Project description:ObjectivesTo evaluate the durability of effects of a computer-assisted version of cognitive behavioral therapy (CBT) as treatment for substance dependence through a 6-month follow-up.MethodsFollowing a randomized clinical trial in which 73 individuals seeking outpatient treatment for substance dependence in an outpatient community setting were randomized to either standard treatment-as-usual (TAU) or TAU with 8 weeks of biweekly access to computer-based training for CBT (CBT4CBT), participants were interviewed 1, 3, and 6 months after the termination of study treatments.ResultsSixty of the 73 participants were reached for follow-up (82%); follow-up rates and availability of data were comparable across treatment conditions. Random regression analyses of use across time indicated significant differences between groups, such that those assigned to TAU increased their drug use across time while those assigned to CBT4CBT tended to improve slightly. The durability of the CBT4CBT effect remained even after controlling for treatment retention, treatment substance use outcomes, and exposure to other treatment during the follow-up period.ConclusionsComputerized CBT4CBT appears to have both short-term and enduring effects on drug use.
Project description:The study is a systematic review and meta-analysis of prospective randomised control studies and prospective cohort studies of mid-term functional outcome of total knee replacement undertaken using imageless computer navigation compared with conventional instrumented total knee replacement. The literature search strategy included a search of the electronic databases, visual scanning of reference lists, hand searching of key journals and conference proceedings, and abstracts, citations, and trial registers. In total, 440 papers were retrieved after removal of duplicates, and with further screening, 11 papers were included in the systematic review and 6 papers were considered appropriate for meta-analysis. Analysis of the data showed evidence of a modest improvement in functional outcome at mid-term follow-up with use of imageless computer navigation assistance compared with conventional instrumented total knee replacement with a total score point estimate of 3.36 confidence interval (CI) (- 0.583, 7.298), objective score point estimate of 1.45 CI (0.11, 2.799), and functional score point estimate of 2.4, CI (- 1.174, 5.977). The predominant risk of bias was from random allocation and attrition. There is evidence of a modest improvement in functional outcome with the use of imageless computer navigation assistance compared with conventional instrumented total knee replacement at mid-term follow-up.
Project description:Background: Although pericallosal artery aneurysms (PAAs) are relatively uncommon, accounting for only 1-9% of all intracranial aneurysms (IAs), they exhibit a considerably high propensity to rupture. Nevertheless, our current knowledge of the risk factors for PAA rupture is still very limited. To fill this gap, we investigated rupture risk factors for PAAs based on morphological computer-assisted semiautomated measurement (CASAM) and hemodynamic analysis. Methods: Patients with PAAs were selected from the IA database in our institute and their baseline data were collected. Morphological parameters were measured in all enrolled patients by applying CASAM. Computational fluid dynamics simulation (CFD) was performed to evaluate the hemodynamic difference between ruptured and unruptured PAAs. Results: From June 2017 to June 2020, among 2141 patients with IAs in our institute, 47 had PAAs (2.2%). Thirty-one patients (mean age 57.65 ± 9.97 years) with 32 PAAs (20 unruptured and 12 ruptured) were included in the final analysis. Comparing with unruptured PAAs, ruptured PAAs had significantly higher aspect ratio (AR), mean normalized wall shear stress (NWSS), and mean oscillatory shear index (OSI) values than the unruptured PAAs (all P < 0.05) in univariate analyses. Multivariable analysis showed that a high mean OSI was an independent risk factor for PAA rupture (OR = 6.45, 95% CI 1.37-30.32, P = 0.018). Conclusion: This preliminary study indicates that there are morphological and hemodynamic differences between ruptured and unruptured PAAs. In particular, a high mean OSI is an independent risk factor for PAA rupture. Further research with a larger sample size is warranted in the future.