"Instant 3D" Angiography: Novel Technique for Rapid Conversion of 2D Angiograms into 3D Stereoscopic Videos.

BACKGROUND: Rotational angiography, often referred to as a "spin", is typically presented in 2D. Since rotational angiograms are composed of images acquired from multiple angles, we took advantage of this property to develop a method for converting any rotational angiogram into a 3 dimensional (3D) video. METHODS: Our aim was to develop a low cost and easily distributable solution without requiring additional hardware or altering acquisition techniques. Six previously acquired rotational angiograms from our institution were imported using custom-written code and exported as anaglyph (red-cyan) videos. RESULTS: The resulting 3D videos convey anatomical depth that is not apparent from viewing the 2D images alone. Processing time was 1.3 ± 0.6 s (mean ± SD) per angiogram. The only associated cost was $10 for red-cyan 3D glasses. Using our software, any rotational angiogram with at least 0.3 frames per degree of rotation can be converted into 3D. CONCLUSIONS: Our solution is an inexpensive and rapid method for generating stereoscopic videos from existing angiograms. It does not require any additional hardware and is readily deployable in low-resource settings. Because the videos are in anaglyph format, they are viewable on any 2 dimensional (2D) display in the interventional suite or operating room, on a mobile device, or at home.

Comparison of Two Drainage Systems on Chronic Subdural Hematoma Recurrence.

BACKGROUND: Chronic subdural hematoma (CSDH) is a common type of intracranial hemorrhage, especially among the elderly, with a recurrence rate as high as 33%. Little is known about the best type of drainage system and its relationship with recurrence. In this study, we compare the use of two drainage systems on the recurrence rate of CSDH. METHODS: We retrospectively analyzed the charts of 172 CSDH patients treated with bedside twist drill craniostomy (TDC) and subdural drain insertion. Patients were divided into two groups: group A (n = 123) received a pediatric size nasogastric tube [NGT]), whereas group B (n = 49) had a drain commonly used for external ventricular drainage (EVD). Various demographic and radiologic data were collected. Our main outcome was recurrence, defined as symptomatic re-accumulation of hematoma on the previously operated side within 3 months. RESULTS: In all, 212 cases of CSDH were treated in 172 patients. The majority of patients were male (78%) and had a history of previous head trauma (73%). Seventeen cases had recurrence, 11 in group A and 6 in group B. The use of antiplatelet and anticoagulation agents was associated with recurrence (p = 0.038 and 0.05, respectively). There was no difference between both groups in terms of recurrence (odds ratio [OR] = 1.42; 95% confidence interval [CI]: 0.49-4.08; p = 0.573). CONCLUSION: CSDH is a common disease with a high rate of recurrence. Although using a drain postoperatively has shown to reduce the incidence of recurrence, little is known about the best type of drain to use. Our analysis showed no difference in the recurrence rate between using the pediatric size NGT and the EVD catheter post-TDC.

Computed Tomography Angiography Compared with Computed Tomography Perfusion in the Diagnosis of Cerebral Vasospasm: A Systematic Review and Meta-Analysis.

INTRODUCTION: Cerebral vasospasm (CV) is a serious complication after subarachnoid hemorrhage; however, swift identification can be challenging. Computed tomography perfusion (CTP) directly measures tissue perfusion and may better screen for CV compared with other modalities. This systematic review summarizes studies assessing the diagnostic performance of computed tomography angiography (CTA) and CTP in identifying CV. METHODS: The search strategy drew from English language publications in the PubMed, Embase, Medline, and Cochrane databases from January 1996 to September 2021. Diagnosis of CV by digital subtraction angiography was the reference standard. Pooled sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), positive likelihood ratios, negative likelihood ratios, and summary receiver operating characteristic curve were calculated. The methodological index for nonrandomized studies tool was employed to assess the quality of the studies. RESULTS: The search generated 22 studies. Seven CTA studies and 6 CTP investigations provided sufficient data for meta-analysis. Following pooled estimates, CTA carried a sensitivity of 0.76 (95% confidence interval [CI], 0.72-0.80), specificity of 0.93 (95% CI, 0.92-0.95), PPV of 0.77 (95%, 0.76-0.79), and NPV of 0.81 (95%, 0.79-0.82). CTP carried a sensitivity of 0.86 (95%, 0.81-0.92), specificity of 0.97 (95%, 0.95-0.98), PPV of 0.94 (0.89-0.98), and NPV of 0.94 (0.91-0.97). Using the methodological index for nonrandomized studies tool, the evidence was rated as overall moderate quality. CONCLUSIONS: This meta-analysis on the diagnostic performance of CTA and CTP in identifying CV suggests that CTP may carry greater diagnostic accuracy compared with CTA. The clinical significance of this difference should be delineated through future prospective studies.

Cerebrovascular damage after midlife transient hypertension in non-transgenic and Alzheimer's disease rats.

Hypertension, including transient events, is a major risk factor for developing late-onset dementia and Alzheimer's disease (AD). Anti-hypertensive drugs facilitate restoration of normotension without amelioration of increased dementia risk suggesting that transient hypertensive insults cause irreversible damage. This study characterized the contribution of transient hypertension to sustained brain damage as a function of normal aging and AD. To model transient hypertension, we treated F344TgAD and non-transgenic littermate rats with L-NG-Nitroarginine methyl ester (L-NAME) for one month, ceased treatment and allowed for a month of normotensive recovery. We then examined the changes in the structure and function of the cerebrovasculature, integrity of white matter, and progression of AD pathology. As independent factors, both transient hypertension and AD compromised structural and functional integrity across the vascular bed, while combined effects of hypertension and AD yielded the largest deficits. Combined effects of transient hypertension and AD genotype resulted in loss of cortical myelin particularly in the cingulate cortex which is crucial for cognitive function. Increased cerebral amyloid angiopathy, a prominent pathology of AD, was detected after transient hypertension as were up- and down-regulation of proteins associated with cerebrovascular remodeling - osteopontin, ROCK1 and ROCK2, in F344TgAD rats even 30 days after restoration of normotension. In conclusion, transient hypertension caused permanent cerebrovasculature and brain parenchymal damage in both normal aging and AD. Our results corroborate human studies that have found close correlation between transient hypertension in midlife and white matter lesions later in life outlining vascular pathologies as pathological links to increased risk of dementia.

Assessment of Frailty in Predicting Surgical Outcomes in Patients with Chronic Subdural Hematomas: Retrospective Chart Review.

BACKGROUND: The aim of this study is to determine if frailty, defined as modified frailty index (MFI) >2.7, correlated with worse postoperative outcomes in patients with chronic subdural hematomas (CSDHs). We also compare the predictive ability of the MFI with another widely used frailty measure, the Clinical Frailty Scale (CFS). METHODS: We conducted a retrospective chart review of elderly patients (≥65 years) who underwent a twist-drill craniostomy for the evacuation of CSDH at Hamilton General Hospital, Canada, between 2016 and 2018. The primary outcome was the modified Rankin Scale scores at discharge. Logistic regression analyses and receiver operating characteristic curves were carried out to further analyze the factors that influenced independence and functional improvement at discharge. RESULTS: Frail patients were significantly more dependent at discharge (P < 0.0001) and had a lower rate of functional improvement (P = 0.003). When compared with frailty measured by the MFI, frailty as measured by the CFS had a stronger association with functional independence (odds ratio [OR]: 0.081 [0.031, 0.211] vs. OR: 0.256 [0.124, 0.529]) and functional improvement (OR: 0.272 [0.106, 0.693] vs. OR: 0.406 [0.185,0.889]) on logistic regression analyses. Area under the receiver operating characteristic curve analyses showed that the inclusion of frailty into our predictive models improved accuracy. CONCLUSIONS: Elderly patients presenting with CSDH who are frail (MFI >0.27) have significantly worse functional outcomes following twist-drill craniostomies. Therefore assessing frailty in this population is important before managing these patients, and for this purpose the CFS is a superior predictor of postoperative function than the MFI.

Combinatorial Treatment Using Umbilical Cord Perivascular Cells and Aß Clearance Rescues Vascular Function Following Transient Hypertension in a Rat Model of Alzheimer Disease.

Transient hypertension is a risk factor for Alzheimer disease (AD), but the effects of this interaction on brain vasculature are understudied. Addressing vascular pathology is a promising avenue to potentiate the efficacy of treatments for AD. We used arterial spin labeling magnetic resonance imaging to longitudinally assess brain vascular function and immunohistopathology to examine cerebrovascular remodeling and amyloid load. Hypertension was induced for 1 month by administration of l-NG-nitroarginine-methyl-ester in TgF344-AD rats at the prodromal stage. Following hypertension, nontransgenic rats showed transient cerebrovascular changes, whereas TgF344-AD animals exhibited sustained alterations in cerebrovascular function. Human umbilical cord perivascular cells in combination with scyllo-inositol, an inhibitor of Aß oligomerization, resulted in normalization of hippocampal vascular function and remodeling, in contrast to either treatment alone. Prodromal stage hypertension exacerbates latter AD pathology, and the combination of human umbilical cord perivascular cells with amyloid clearance promotes cerebrovascular functional recovery.