Current Accuracy of Augmented Reality Neuronavigation Systems: Systematic Review and Meta-Analysis

BACKGROUND Augmented reality neuronavigation (ARN) systems can overlay three-dimensional anatomy and pathology without the need for a two-dimensional external monitor. Accuracy is crucial for their clinical applicability. We performed a systematic review regarding the reported accuracy of ARN systems and compared them with the accuracy of conventional infrared neuronavigation (CIN). OBJECTIVE Explore the current navigation accuracy of ARN systems and compare them with CIN. METHODS Pubmed and Embase were searched for ARN and CIN systems. For ARN: type of system, method of patient-to-image registration, accuracy method and accuracy of the system was noted. For CIN: navigation accuracy, expressed as target registration error (TRE), was noted. A meta-analysis was performed comparing the TRE of ARN and CIN systems. RESULTS 35 studies were included, 12 for ARN and 23 for CIN. ARN systems were divided into head-mounted display and heads-up display. In ARN, four methods were encountered for patient-to-image registration, of which point-pair matching was the one most frequently used. Five methods for assessing accuracy were described. 94 TRE measurements of ARN systems were compared with 9058 TRE measurements of CIN systems. Mean TRE was 2.5 mm (CI 95% 0.7 - 4.4) for ARN systems and 2.6 mm (CI 95% 2.1 - 3.1) for CIN systems. CONCLUSIONS In ARN, there seems to be lack of agreement regarding the best method to assess accuracy. Nevertheless, ARN systems seem able to achieve an accuracy comparable with CIN systems. Future studies should be prospective and compare TREs which should be measured in a standardized fashion

Comparing the influence of mixed reality, a 3D viewer, and MRI on the spatial understanding of brain tumours

Background: Multiple 3D visualization techniques are available that obviates the need for the surgeon to mentally transform the 2D planes from MRI to the 3D anatomy of the patient. We assessed the spatial understanding of a brain tumour when visualized with MRI, 3D models on a monitor or 3D models in mixed reality.Methods: Medical students, neurosurgical residents and neurosurgeons were divided into three groups based on the imaging modality used for preparation: MRI, 3D viewer and mixed reality. After preparation, the participants needed to position, scale, and rotate a virtual tumour inside a virtual head of the patient in the same orientation as the original tumour would be. Primary outcome was the amount of overlap between the placed tumour and the original tumour to evaluate accuracy. Secondary outcomes were the position, volume and rotation deviation compared to the original tumour.Results: A total of 12 medical students, 12 neurosurgical residents, and 12 neurosurgeons were included. For medical students, the mean amount of overlap for the MRI, 3D viewer and mixed reality group was 0.26 (0.22), 0.38 (0.20) and 0.48 (0.20) respectively. For residents 0.45 (0.23), 0.45 (0.19) and 0.68 (0.11) and for neurosurgeons 0.39 (0.20), 0.50 (0.27) and 0.67 (0.14). The amount of overlap for mixed reality was significantly higher on all expertise levels compared to MRI and on resident and neurosurgeon level also compared to the 3D viewer. Furthermore, mixed reality showed the lowest deviations in position, volume and rotation on all expertise levels.Conclusion: Mixed reality enhances the spatial understanding of brain tumours compared to MRI and 3D models on a monitor. The preoperative use of mixed reality may therefore support the surgeon to improve spatial 3D related surgical tasks such as patient positioning and planning surgical trajectories

Preventable and Non-Preventable Adverse Drug Events in Hospitalized Patients A Prospective Chart Review in the Netherlands

Background: Medication safety research and clinical pharmacy practice tc day is primarily focused on managing preventable adverse drug events (pADEs). Determinants of both pADEs and non-preventable adverse drug react ons (ADRs) have been identified. However, relatively little is known on the overlap between these determinants and the balance of preventable and non-preventable harm inpatients experience in modern computerized hospitals. Objective: The aim of this study was to analyse the prevalence of pADEs and non-preventable ADRs as well as the determinants, including multimorbidity, of these ADEs, i.e. both pADEs and ADRs. Methods: Adverse events experienced by patients admitted to two Dutch hospitals with functioning computerized physician order entry (CPOE) systems were prospectively identified through chart review. Adverse events were divided into pADEs (i.e. as a result of a medication error) and non-preventable ADRs. In both cases, a causal relationship between adverse events and patients' drugs was established using the simplified Yale algorithm. Study data were collected anytime between April 2006 and May 2008 over a 5-month period at each hospital ward included in the study, beginning from 8 weeks after CPOE was implemented at the ward. Results: pADEs and non-preventable ADRs were experienced by 349 (58%) patients, of whom 307 (88%) had non-preventable ADRs. Multimorbidity (adjusted odds ratio [OR(adj)] 1.90; 95% CI 1.44, 2.50; OR(adj) 1.28; 95% CI 1.14, 1.45, respectively), length of stay (OR(adj) 1.13; 95% CI 1.06, 1.21; OR(adj) 1.11; 95% CI 1.07, 1.16, respectively), admission to the geriatric ward (OR(adj) 7.78; 95% CI 2.15, 28.13; OR(adj) 3.82; 95% CI 1.73, 8.45, respectively) and number Of medication orders (OR(adj) 1.25; 95% CI 1.16, 1.35; OR(adj) 1.13; 95% CI 1.06, 1.21, respectively) were statistically significantly associated with pADEs and ADRs. Admission to the gastroenterology/rheumatology ward (OR(adj) 0.22; 95% CI 0.06, 0.77; OR(adj) 0.40; 95% CI 0.24, 0.65, respectively) was inversely related to both pADEs and ADRs. Other determinants for ADRs only were female sex (OR(adj) 1.77; 95% CI 1.12, 2.80) and use of drugs affecting the nervous system (OR(adj) 1.83; 95% CI 1.09, 3.07). Age was a significant determinant for pADEs only (OR(adj) 1.07; 95% CI 1.03, 1.11). Conclusions: In this study more than half of the patients admitted to the hospitals are harmed by drugs, of which most are non-serious, non-preventable ADRs (after the introduction of CPOE). Determinants of both pADEs and ADRs overlap to a large extent. Our results imply the need for signalling early potential adverse events that occur during the normal use of drugs in multimorbid patients or those in geriatric wards. Subsequent therapeutic interventions may improve the well-being of hospitalized patients to a greater extent than focusing on errors in the medication process only

Small artery elasticity is decreased in patients with systemic lupus erythematosus without increased intima media thickness

Introduction: The objectives of this study were to determine small arterial elasticity (SAE) in systemic lupus erythematosus (SLE) and to investigate its relationship with intima media thickness (IMT), accumulation of advanced glycation end products (AGEs), endothelial activation and inflammation. Methods: Thirty SLE patients with inactive disease and 30 age- and sex-matched healthy controls were included. Twenty patients with essential hypertension (EH) served as positive control. SAE was assessed by pulse-wave analysis using tonometric recordings of the radial artery. IMT of the carotid arteries was measured by ultrasound. AGE accumulation was assessed with an AGE-reader. Endothelial activation markers and C-reactive protein (CRP) were determined by enzyme-linked immunosorbent assay (ELISA). Results: SAE was decreased in SLE (P = 0.01) and further decreased in EH (P <0.01) compared to healthy controls. IMT was increased in EH (P <0.05), but not in SLE. AGE accumulation was increased in SLE (P <0.05) and further increased in EH (P <0.01) compared to healthy controls. Endothelial activation markers and CRP were increased in SLE but not in EH. SAE related to AGE accumulation (r = -0.370, P <0.05), CRP (r = -0.429, P <0.05) and creatinine clearance (r = 0.440, P <0.05), but not to IMT and endothelial activation markers. In multivariate analysis SLE was an independent predictor of SAE. Conclusions: SAE is decreased in SLE patients without increased IMT, independently of traditional cardiovascular risk factors. Longitudinal studies are needed to investigate whether SAE, endothelial activation and AGE accumulation are early markers for cardiovascular disease in SLE

Fracture Risk Reduction by Bisphosphonates in Mastocytosis?

BACKGROUND: Fragility fractures (FFxs) and osteoporosis are frequent manifestations of indolent systemic mastocytosis (ISM). So far, the effect of antiosteoporotic therapy on FFxs has scarcely been investigated. OBJECTIVE: This study evaluates the long-term effect of bisphosphonate treatment on FFxs, bone mineral density (BMD), and bone resorption in patients with ISM in daily clinical practice. METHODS: Patients with ISM who received bisphosphonates because of osteoporosis and/or FFxs were retrospectively analyzed (n = 58). Fractures were recorded by vertebral fracture assessment, X-rays of the thoracolumbar spine, medical records, and a questionnaire. Five-year analysis (n = 30) was made by comparing observed 5-year FFx risk with MastFx-predicted FFx risk for patients with ISM not treated with antiosteoporotic drugs and analyzing 5-year change in BMD and serum collagen C telopeptide (sCTx) Z-scores. RESULTS: During the median follow-up of 7.3 years, 14 of 58 patients suffered 40 FFxs. Five- and 10-year FFx-free survival were 81.9% (standard error [SE], 5.5%) and 67.0% (SE, 7.7%), respectively. FFx risk was significantly higher in patients with previous vertebral FFxs (P = .004), lower femoral BMD at baseline (P = .042), and history of anaphylaxis (P = .028). No 5-year FFx risk reduction could be proven, possibly due to the small sample size. The lumbar BMD Z-score significantly increased from median (interquartile range [IQR]) -2.20 (-2.80 to -1.50) to -1.50 ( -2.30 to -0.60) (P<.001, n = 27). The sCTx Z-score decreased from median 0.71 (IQR, -0.59 to 2.39) to -0.95 (-1.30 to -0.16) (P = .008, n = 15). CONCLUSION: Bisphosphonates significantly increase BMD and decrease sCTx in patients with ISM. However, FFxs still frequently occur. Especially patients with previous FFxs remain at high risk of new FFxs. (C) 2020 American Academy of Allergy, Asthma & Immunolog

autoTICI: Automatic Brain Tissue Reperfusion Scoring on 2D DSA Images of Acute Ischemic Stroke Patients

The Thrombolysis in Cerebral Infarction (TICI) score is an important metric for reperfusion therapy assessment in acute ischemic stroke. It is commonly used as a technical outcome measure after endovascular treatment (EVT). Existing TICI scores are defined in coarse ordinal grades based on visual inspection, leading to inter- and intra-observer variation. In this work, we present autoTICI, an automatic and quantitative TICI scoring method. First, each digital subtraction angiography (DSA) sequence is separated into four phases (non-contrast, arterial, parenchymal and venous phase) using a multi-path convolutional neural network (CNN), which exploits spatio-temporal features. The network also incorporates sequence level label dependencies in the form of a state-transition matrix. Next, a minimum intensity map (MINIP) is computed using the motion corrected arterial and parenchymal frames. On the MINIP image, vessel, perfusion and background pixels are segmented. Finally, we quantify the autoTICI score as the ratio of reperfused pixels after EVT. On a routinely acquired multi-center dataset, the proposed autoTICI shows good correlation with the extended TICI (eTICI) reference with an average area under the curve (AUC) score of 0.81. The AUC score is 0.90 with respect to the dichotomized eTICI. In terms of clinical outcome prediction, we demonstrate that autoTICI is overall comparable to eTICI.Comment: 10 pages; submitted to IEEE TM