Flat Panel Detector CT Research Articles

DOT sign indicates persistent hypoperfusion and poor outcome in patients with incomplete reperfusion following thrombectomy

BackgroundDistal occlusions associated with incomplete reperfusion (expanded Thrombolysis in Cerebral Infarction, <eTICI 3) may not reperfuse spontaneously and thus prompt ischemia (ie, persistent hypoperfusion). We aimed to assess whether the...

Incidence, Risk Factors, and Clinical Implications of Subarachnoid Hyperdensities on Flat-Panel Detector CT following Mechanical Thrombectomy in Patients with Anterior Circulation Acute Ischemic Stroke.

Flat-panel detector CT immediately after mechanical thrombectomy can detect complications, including early hemorrhagic transformation and subarachnoid hyperdensities. The clinical significance of subarachnoid hyperdensities in patients undergoing mechanical thrombectomy remains unclear. We studied 223 patients who underwent mechanical thrombectomy for anterior circulation stroke who had flat-panel detector CT performed immediately after the procedure and had follow-up imaging within 24 hours. Subarachnoid hyperdensity severity was categorized into 5 grades (subarachnoid hyperdensities, 0: absent to subarachnoid hyperdensities, IV: extensive). Baseline and procedural characteristics as well as outcome measures were analyzed using group comparisons and multivariable logistic regression analyses. Overall, 100/223 (45%) patients showed subarachnoid hyperdensities on immediate postinterventional flat-panel detector CT. The factors associated with an increased subarachnoid hyperdensity risk were the following: medium-vessel occlusion or distal-vessel occlusion compared with a large-vessel occlusion, a more distal device position, a higher number of device passes, a larger volume of contrast applied, worse final reperfusion expanded TICI, and after receiving IV thrombolysis. The occurrence of subarachnoid hyperdensity grades II-IV was independently associated with worse functional outcomes (adjusted OR for mRS, 3-6: 2.2; 95% CI 1.1-4.3), whereas patients with subarachnoid hyperdensity grade I had outcomes similar to those in patients without subarachnoid hyperdensities. Our study identified risk factors for subarachnoid hyperdensities, most of which reflect increasingly challenging procedures or more peripheral recanalization attempts. The presence of subarachnoid hyperdensity grades II-IV was associated with poorer outcomes, suggesting the need for personalized strategies to reduce its incidence and severity or potentially improve recovery after subarachnoid hyperdensities.

Connecting the DOTs: a novel imaging sign on flat-panel detector CT indicating distal vessel occlusions after thrombectomy

BackgroundImmediate non-contrast post-interventional flat-panel detector CT (FPDCT) has been suggested as an imaging tool to assess complications after endovascular therapy (EVT). We systematically investigated a new imaging finding of focal...

Flat-panel detector CT to assess intracranial hemorrhage immediately following mechanical thrombectomy.

The risk of symptomatic intracranial hemorrhage (ICH) approaches 5% despite mechanical thrombectomy (MT) efficacy for ischemic stroke secondary to large vessel occlusion. Flat-panel detector CT (FDCT) imaging with Syngo Dyna CT imaging (Siemens Medical Solutions, Malvern, PA) can be used immediately following MT to detect ICH. To evaluate the accuracy and reliability of FDCT imaging with Dyna CT compared to conventional post-MT CT and MRI. Head FDCT (20second, 70kV) was performed immediately following MT on 26 consecutive patients; postprocedural CT or MRI was obtained ∼24hours later. Two blinded, independent neuroradiologists evaluated all imaging, identifying ICH, stroke, and presence of subarachnoid contrast. Cohen's κ statistic was used to assess interrater agreement for each imaging outcome and compared the FDCT to conventional imaging. FDCT for ICH demonstrated a strong degree of interrater reliability (κ=0.896; 95% confidence interval [CI], 0.734-1.057). Negligible reliability was seen for ischemia determination on immediate post-MT FDCT (κ=0.149; 95% CI, -0.243 to 0.541). ICH evaluation between FDCT and post-MT conventional CT revealed modest interrater reliability (κ=0.432; 95% CI, -0.100 to 0.965), which did not reach statistical significance. There was no substantive reliability in the evaluation of ICH between FDCT and post-MT MRI (κ=0.118, 95% CI, -0.345 to 0.580). FDCT, such as Dyna CT, immediately post-MT is a promising tool that can expedite the detection of ICH with a high degree of reliability, although the detection of ischemic parenchymal changes is limited.

The Utility of Multimodal Imaging and Artificial Intelligence Algorithms for Overlying Two Volumes in the Decision Chain for the Treatment of Complex Pathologies in Interventional Neuroradiology—A Case Series Study

3D rotational angiography is now increasingly used in routine neuroendovascular procedures--in particular, for situations where the analysis of two overlayed sets of volume imaging proves useful for planning the treatment strategy or for confirming the optimal apposition of the intravascular devices used. The aim of this study is to identify and describe the decision algorithm for which the overlay function of 3D rotational angiography volumes, high-resolution contrast-enhanced flat panel detector CT adapted for intravascular devices (VasoCT/DynaCT), non-enhanced flat detector C-arm volume acquisition functionality integrated with the angiography equipment (XperCT/DynaCT), and isovolumetric MRI volumes were all used in treatments performed in a series of 29 patients. Two superposed 3DRA volumes were used in the treatment aneurysms located at the junction of two vascular territories and for arteriovenous malformations with compartments fed from different vascular territories. The superposition function of a preoperatively acquired 3DRA volume and a postoperatively acquired VasoCT volume provides accurate information about the apposition of neuroendovascular endoprostheses used in the treatment of aneurysms. The automatic overlay function generated by the 3D workstation is particularly useful, but in about 50% of cases it requires manual operator-dependent correction, requiring a certain level of experience. In our experience, multimodal imaging brings an important benefit, both in the treatment decision algorithm and in the assessment of neuroendovascular treatment efficacy.

Correlation of Collateral Scores Derived from Whole-Brain Time-Resolved Flat Panel Detector Imaging in Acute Ischemic Stroke.

Flat panel detector CT imaging allows simultaneous acquisition of multiphase flat panel CTA and flat panel CTP imaging directly in the angio suite. We compared collateral assessment derived from multiphase flat panel CTA and flat panel CTP with collateral assessment derived from DSA as the gold-standard. We performed a retrospective analysis of patients with occlusion of the first or second segment of the MCA who underwent pre-interventional flat panel detector CT. The hypoperfusion intensity ratio as a correlate of collateral status was calculated from flat panel CTP (time-to-maximum > 10 seconds volume/time-to-maximum > 6 seconds volume). Intraclass correlation coefficients were calculated for interrater reliability for the Calgary/Menon score for multiphase flat panel CTA and for the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score for DSA collateral scores. Correlations of the hypoperfusion intensity ratio, multiphase flat panel CTA score, and the ASITN/SIR score were calculated using the Spearman correlation. From November 2019 to February 2020, thirty patients were included. Moderate interrater reliability was achieved for the ASITN/SIR DSA score (0.68; 95% CI, 0.50-0.82) as well as for the Calgary/Menon multiphase flat panel CTA score (0.53; 95% CI, 0.29-0.72). We found a strong correlation between the ASITN/SIR DSA and Calgary/Menon multiphase flat panel CTA score (ρ = 0.54, P = .002) and between the hypoperfusion intensity ratio and the Calgary/Menon multiphase flat panel CTA score (ρ = -0.57, P < .001). The correlation was moderate between the hypoperfusion intensity ratio and the ASITN/SIR DSA score (ρ = -0.49, P = .006). The infarct core volume correlated strongly with the Calgary/Menon multiphase flat panel CTA score (ρ = -0.66, P < .001) and the hypoperfusion intensity ratio (ρ = 0.76, P < .001) and correlated moderately with the ASITN/SIR DSA score (ρ = -0.46, P = .01). The Calgary/Menon multiphase flat panel CTA score and the hypoperfusion intensity ratio correlated with each other and with the ASITN/SIR DSA score as the gold-standard. In our cohort, the collateral scoring derived from flat panel detector CT was clinically reliable.

Feasibility of FDCT Early Brain Parenchymal Blood Volume Maps in Predicting Short-Term Prognosis in Patients With Aneurysmal Subarachnoid Hemorrhage.

PurposeAneurysmal subarachnoid hemorrhage (SAH) is accompanied by cerebral perfusion changes. We aimed to measure the parenchymal blood volume (PBV) maps acquired by C-arm flat-panel detector CT (FDCT) to assess the cerebral blood volume at an early stage in aneurysmal SAH and to explore the correlation with the outcomes at discharge.MethodsData of 66 patients with aneurysmal SAH who underwent FDCT PBV examination were retrospectively analyzed. The PBV of regions of interest, including the cortices of the bilateral frontal lobe, the parietal lobe, the occipital lobe, and the cerebral hemisphere, as well as the basal ganglia, were measured and quantitatively analyzed. The clinical and imaging data of the patients were also collected, and logistic regression analysis was performed to explore the correlation between the perfusion parameters and outcomes at discharge.ResultsThe favorable and poor outcomes at discharge were found in 37 (56.06%) and 29 (43.94%) patients, respectively. The whole-brain PBV was significantly correlated with the Hunt-Hess grades (p < 0.005) and the WFNSS grades (p < 0.005). The whole-brain PBV of the poor prognosis was significantly higher than that of the favorable prognosis (35.17 ± 7.66 vs. 29.78 ± 5.54, p < 0.005). The logistic regression analysis showed that the PBV of the parietal lobe at the bleeding side (OR = 1.10, 95%CI: 1.00–1.20, p = 0.04) was an independent risk factor predicting the short-term prognosis.ConclusionsParenchymal blood volume (PBV) maps could reflect the cerebral blood volume throughout the brain to characterize its perfusion status at an early stage in aneurysmal SAH. It enables a one-stop imaging evaluation and treatment in the same angio-suite and may serve as a reliable technique in clinical assessment of aneurysmal SAH.

Evaluation of time-resolved whole brain flat panel detector perfusion imaging using RAPID ANGIO in patients with acute stroke: comparison with CT perfusion imaging

BackgroundIn contrast to conventional CT perfusion (CTP) imaging, flat panel detector CT perfusion (FD-CTP) imaging can be acquired directly in the angiosuite.ObjectiveTo evaluate time-resolved whole brain FD-CTP imaging and assess...

Abstract 128: Evaluation Of Flat Panel Detector Whole Brain Perfusion Imaging In Acute Stroke Patients: Comparison With Computer Tomography Perfusion Imaging

Introduction: In acute ischemic stroke, perfusion imaging facilitates detection of the occluded vessels, influences decision-making regarding therapy options, and is recommended especially in delayed time windows. In contrast to conventional CT perfusion (CTP), flat panel detector CT perfusion (FD-CTP) can be acquired directly in the angio suite. To evaluate FD-CTP imaging, we assessed clinically important qualitative and quantitative perfusion parameters in correlation to prior acquired conventional CTP using the new RAPID for Angio software. Methods: We included patients with ICA-, M1, or M2-occlusions from 6 centers. All patients underwent mechanical thrombectomy (MT) with pre-interventional conventional CTP and FD-CTP imaging. Quantitative performance was determined by comparing volumes of infarct core, penumbral tissue, and mismatch volume. Eligibility for MT according to the perfusion imaging criteria of DEFUSE 3 was determined for each case for conventional CTP and FD-CTP imaging. A blinded reader identified the occlusion site based on visual inspection of the FD-CTP maps. Results: We included 77 patients and FD-CTP was technical adequate in 49 patients (63.6%). The final analysis included 20 patients (further reasons for exclusion were n=20 technical inadequate conventional CTP, n=2 reperfusion between scans, n=2 exceeding the time limit between scans, n=2 posterior occlusion and n=3 MRI-perfusion). Conventional rCBF &lt;30% and FD-CTP rCBF &lt;45% showed good correlation (R 2 = 0.84). Conventional CTP Tmax &gt;6s/FD-CTP Tmax &gt;6s and CTP Mismatch/FD-CTP Mismatch showed more variability (R 2 = 0.57, and R 2 = 0.33 respectively). Based on FD-CTP, 16/20 (80%) patients met the inclusion criteria for MT according to the DEFUSE 3 perfusion criteria in contrast to 18/20 (90%) patients based on conventional CTP. A blinded reader correctly determined the specific vessel occlusions in 34/38 cases (89.5%). Conclusion: In our multicenter study, time-resolved whole-brain FD-CTP was technically feasible and qualitative and quantitative perfusion results correlated overall well with conventional CTP. This potentially enables a direct to the angio approach to be established and may increase the chances of good clinical outcome.

Short-Vessel Occlusion Might Indicate Higher Possibility of Success in Reperfusion following Mechanical Thrombectomy in Acute Middle Cerebral Artery Occlusion

Background: The impact of the length of the occluded vessel in acute large-vessel occlusion on successful reperfusion by mechanical thrombectomy remains unclear. This study evaluated whether diameter and length of the occluded vessel in acute middle cerebral artery (MCA) occlusion might relate to successful reperfusion following mechanical thrombectomy. Methods: This retrospective study included patients with acute MCA occlusion who underwent intra-aortic injection of contrast medium to obtain maximum intensity projection (MIP) images acquired by flat-panel detector computed tomography (FD-CT) equipped with an angiographic system. All patients received mechanical thrombectomy and were divided into two groups: those with successful reperfusion (Thrombolysis in Cerebral Infarction [TICI] 2b/3) and those without. We compared the diameter and length of the occluded vessel between the groups. In the sub-analysis of patients with stent retriever use, ratio of length of occluded vessel to length of the active zone was compared. Results: We enrolled 29 patients (median age: 73, M1 occlusion: 51%, stent retriever use: 72%). Eighteen patients achieved TICI 2b/3 with significantly larger distal end diameter (1.7 [interquartile range: 1.5–1.9] vs. 1.2 [1.2–1.5] mm, p = 0.007) and shorter length (7.1 [4.9–9.7] vs. 12.3 [7.2–15.8] mm, p = 0.043) of the occluded vessel. Sub-analysis of 21 patients showed that the cut-off value for TICI 2b/3 reperfusion was 0.32 as the ratio between the occluded vessel and stent retriever active zone (receiver operating characteristic area under the curve: 0.90). Conclusion: In acute MCA occlusion, larger diameter of the distal end and shorter length of the occluded vessel on FD-CT MIP images might indicate a higher possibility of achieving TICI 2b/3 following mechanical thrombectomy.

Distal Vessel Imaging via Intra-arterial Flat Panel Detector CTA during Mechanical Thrombectomy.

Obtaining information on invisible vasculature distal to the occlusion site helps to deploy a stent retriever safely during mechanical thrombectomy for large-vessel occlusion. It is essential to reduce the amount of contrast used for detecting the vessels distal to the occlusion site because acute ischemic stroke patients tend to have chronic kidney disease and patients with severe chronic kidney disease are at an increased risk of contrast-associated acute kidney injury. We assessed whether vessels distal to the occlusion site during acute ischemic stroke with large-vessel occlusion could be visualized on angiographic images using flat panel detector CT acquired following intra-arterial diluted contrast injection, compared with MRA findings. Between May 2019 and January 2020, we enrolled 28 consecutive patients with large-vessel occlusions of the anterior circulation eligible for mechanical thrombectomy following MR imaging. The patients underwent CBV imaging using flat panel detector CT with an intra-arterial diluted contrast injection instead of intravenous injection. Flat panel detector CT angiographic images reconstructed from the same dataset were evaluated for image quality, collateral status of the MCA territory, and visualization of the vessels distal to the occlusion site. These findings were compared with MRA findings. Twenty-two patients were retrospectively examined. Flat panel detector CT angiographic image quality in 20 patients (91%) was excellent or good. The distal portion of the occluded vessel segment was visualized in 14 patients (70%), while the proximal portion of the segment adjacent to the occluded vessel in 3 (15%) was visualized. No visualization was observed in only 1 patient (5%) with no collateral supply. Flat panel detector CT angiographic images were shown to evaluate vessels distal to the occlusion site more accurately than MRA. In acute ischemic stroke with large-vessel occlusion, flat panel detector CT angiographic images could successfully visualize vessels distal to the occlusion site with a small amount of contrast material.

Infrapopliteal endovascular intervention and the angiosome concept: intraoperative real-time assessment of foot regions' blood volume guides and improves direct revascularization.

There is no consensus for determining which vessel should be revascularized in patients with multiple diseased infrapopliteal arteries. The angiosome concept may guide a more efficient targeted direct revascularization. Therefore, we conducted a study to assess whether the regional evaluation of foot blood volume may guide direct revascularization (DR) and if it will lead to better perfusion improvement than indirect revascularization (IR). We performed a prospective single-center observational cohort study in patients treated in the Department of Vascular Surgery of Peking Union Medical College Hospital from November 2016 to April 2019. Twenty-seven patients treated with endovascular intervention were included. The intraoperative parenchymal blood volume of different foot regions was obtained for each patient using C-arm CT before and after intervention. The intervention procedure significantly increased the overall blood volume (48.95 versus 81.97 ml/1000 ml, p = 0.002). Patients with direct revascularization had a 197% blood volume increase while patients with indirect revascularization had a 39% increase (p = 0.028). The preoperative blood volume was higher in patients with mild symptoms than in patients with severe symptoms (58.20 versus 30.45 ml/1000 ml, p = 0.039). However, in regard to postoperative blood volume, no significant difference was discovered between these two groups (75.05 versus 95.01 ml/1000 ml, p = 0.275). Based on quantitative measurements, we conclude that overall blood volume can rise significantly after the intervention. Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring blood supply through the collateral circulation. Preoperative blood volume is associated with preoperative symptoms. • Flat panel detector CT can obtain intraoperative perfusion status and guide treatment in endovascular intervention. • Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring the blood supply through the collateral circulation. • Patients with severer clinical manifestations have lower blood volumes.

Flat-panel detector CT assessment in stroke to reduce times to intra-arterial treatment: A study of multiphase computed tomography angiography in the angiography suite to bypass conventional imaging.

Bypassing the emergency department and the computed tomography suite by directly transporting to the neuroangiography suite for imaging assessment and treatment may shorten reperfusion times while maintaining proper patient selection. To determine whether flat-panel detector multiphase computed tomography angiography protocol is associated with reduced treatment times and a similar safety profile as the standard imaging protocol. Single-center prospective study of consecutive patients with anterior circulation large vessel occlusion strokes transferred to our facility for consideration of endovascular therapy from May 2016 to December 2017. Those with basilar strokes and/or presenting to the emergency department were excluded. Patients were categorized into two groups: (1) flat-panel detector CT assessment in stroke to reduce times to intra-arterial treatment group, with patients transferred directly to the suite for multiphase computed tomography angiography; and (2) patients undergoing standard protocol including computed tomography ± computed tomography angiography/CT perfusion. The groups were matched for age, baseline National Institute of Health Stroke Scale, and pretreatment glucose. Baseline characteristics, time metrics, and outcomes were compared. Out of 419 patients who underwent endovascular therapy over the study period, 210 patients fit inclusion criteria, with 54 (25.7%) in the flat-panel detector CT assessment in stroke to reduce times to intra-arterial treatment group. After matching, 49 flat-panel detector CT assessment in stroke to reduce times to intra-arterial treatment/control pairs were generated and analyzed. Baseline characteristics were well balanced. Flat-panel detector CT assessment in stroke to reduce times to intra-arterial treatment patients had significantly shorter median door-to-puncture (33 [26.5-47] vs. 55 [44.5-66] min, p < 0.001), door-to-reperfusion (85 [57.5-115.5] vs. 110 [80-153], p = 0.005) and picture-to-puncture (18 [13.5-22.5] vs. 42 [32-47.5] min, p < 0.001) times. There were no differences in rates of successful reperfusion (modified thrombolysis in cerebral infarction 2b-3, 95.9% vs. 100%, p = 0.5), parenchymal hematomas type-2 (4.1% vs. 2%, p = 1.00), good outcome (90-day modified Rankin Scale 0-2, 44.9% vs. 40.8%, p = 0.68), and 90-day mortality (14.3% vs. 22.4%, p = 0.30). Directly transferring patients to angiography and using multiphase computed tomography angiography to determine the eligibility for endovascular therapy is safe and may result in a significant reduction in treatment times. Future larger studies are warranted.

One-Stop Management with Perfusion for Transfer Patients with Stroke due to a Large-Vessel Occlusion: Feasibility and Effects on In-Hospital Times.

In-hospital time delays lead to a relevant deterioration of neurologic outcomes in patients with stroke with large-vessel occlusions. At the moment, CT perfusion is relevant in the triage of late-window patients with stroke. We conducted this study to determine whether one-stop management with perfusion is feasible and leads to a reduction of in-hospital times. In this observational study, we report the first 15 consecutive transfer patients with stroke with externally confirmed large-vessel occlusions who underwent flat panel detector CT perfusion and thrombectomy in the same room. Preinterventional imaging consisted of noncontrast flat panel detector CT and flat panel detector CT perfusion, acquired with a biplane angiography system. The flat panel detector CT perfusion was used to reconstruct a flat panel detector CT angiography to confirm the large-vessel occlusions. After confirmation of the large-vessel occlusion, the patient underwent mechanical thrombectomy. We recorded time metrics and safety parameters prospectively and compared them with those of transfer patients whom we treated before the introduction of one-stop management with perfusion. Fifteen transfer patients underwent flat panel detector CT perfusion and were treated with mechanical thrombectomy from June 2017 to January 2019. The median time from symptom onset to admission was 241 minutes. Median door-to-groin time was 24 minutes. Compared with 23 transfer patients imaged with multidetector CT, it was reduced significantly (24 minutes; 95% CI, 19-37 minutes, versus 53 minutes; 95% CI, 44-66 minutes; P < .001). Safety parameters were comparable between groups. In this small series, one-stop management with perfusion led to a significant reduction of in-hospital times compared with our previous workflow.

Abstract WMP15: Flat Panel Detector CT Assessment in Stroke to Reduce Times to Intra-Arterial Treatment (FAST-IA): A Study of Multi-Phase CTA in the Angiography Suite to Bypass Conventional Imaging

Background: Bypassing the emergency department (ED) and the CT suite by directly transporting to the neuroangiography suite for imaging assessment and treatment may shorten reperfusion times while maintaining proper patient selection. Methods: Single-center prospective study of consecutive patients with anterior circulation LVO strokes transferred to our facility for consideration of endovascular therapy (ET) from 5/2016 to 12/2017. Those with basilar strokes and/or presenting to the ED were excluded. Patients were categorized into two groups: (1) F lat-Panel Detector CT A ssessment in S troke to Reduce T imes to I ntra- A rterial Treatment (FAST-IA) group, with patients transferred directly to the suite for Flat-Panel Detector multiphase CT angiography (FD-mCTA); and (2) Patients undergoing standard protocol including CT+/-CTA/CTP. The groups were matched for age, baseline NIHSS and pre-treatment glucose. Baseline characteristics, time metrics and outcomes were compared. Results: Out of 419 patients that underwent ET over the study period, 210 patients fit inclusion criteria, with 54 (25.7%) in the FAST-IA group. After matching, 49 FAST-IA/Control pairs were generated and analyzed. Baseline characteristics were well-balanced. FAST-IA patients had significantly shorter median door-to-puncture (33[26.5-47] vs 55[44.5-66] minutes, p&lt;0.001), door-to-reperfusion (85[57.5-115.5]vs110[80-153],p=0.005) and picture-to-puncture (18[13.5-22.5]vs 42[32-47.5]minutes, p&lt;0.001)times. There were no differences in rates of successful reperfusion (mTICI 2b-3, 95.9% vs 100%, p=0.5), parenchymal hematomas type-2 (4.1% vs 2%, p=1.00), good outcome (90-day mRS-0-2, 44.9% vs 40.8%, p=0.68) and 90-day mortality (14.3% vs 22.4%,p=0.30). Conclusions: Directly transferring patients to angiography and using FD-mCTA to determine eligibility for ET is safe and results in significant reduction in treatment times. Future larger studies are warranted.

Flat Panel Detector Computed Tomography−Guided Placement of External Ventricular Drains Using the BrainLAB Headband and Precalibrated Disposable Stylet Instrument: A Cadaveric Feasibility Study

The standard freehand method for the insertion of external ventricular drains (EVDs) is associated with high rates of incorrect placement. Use of neuronavigation has been shown to reduce the rates of inaccurately positioned EVDs. We present a novel neuronavigation-based approach for EVD placement using flat panel detector computed tomography (FDCT) imaging. Four cadaveric heads were used for neuronavigated placement of EVDs using the BrainLAB reference headband in combination with laser surface registration and the precalibrated disposable stylet. In 2 cases, conventional multislice CT imaging was performed to reference neuronavigation. In the other 2 cases, preprocedural imaging was performed with FDCT. After inserting the EVDs, all heads were examined again with the identical imaging method as used before the procedure, followed by evaluation of catheter position. Our data demonstrate that FDCT imaging provides adequate image quality for referencing neuronavigation and performing navigated neurosurgery. All EVDs showed an optimal position in the ipsilateral frontal horn. Use of a BrainLAB reference headband combined with laser surface registration and the precalibrated disposable stylet affords the advantage of not requiring rigid fixation in a clamp. Our presented method is fast, accurate, and easy to use. Furthermore, this study is the first to demonstrate that navigated neurosurgery can be performed on the basis of FDCT imaging.

Accuracy of image-guided percutaneous injection into a phantom spinal cord utilizing flat panel detector CT with MR fusion and integrated navigational software

PurposeTo evaluate the accuracy of percutaneous fluoroscopic injection into the spinal cord of a spine phantom utilizing integrated navigational guidance from fused flat panel detector CT (FDCT) and MR datasets....

Retrograde 3D rotational venography (3DRV) for venous sinus stent placement in idiopathic intracranial hypertension

BackgroundDural venous sinus stenting has emerged as an effective and durable treatment for idiopathic intracranial hypertension (IIH). Improved visualization of the venous sinuses can improve stent placement.MethodsWe present two cases...

Intensity-based 2D 3D registration for lead localization in robot guided deep brain stimulation

Intraoperative assessment of lead localization has become a standard procedure during deep brain stimulation surgery in many centers, allowing immediate verification of targeting accuracy and, if necessary, adjustment of the trajectory. The most suitable imaging modality to determine lead positioning, however, remains controversially discussed. Current approaches entail the implementation of computed tomography and magnetic resonance imaging. In the present study, we adopted the technique of intensity-based 2D 3D registration that is commonly employed in stereotactic radiotherapy and spinal surgery. For this purpose, intraoperatively acquired 2D x-ray images were fused with preoperative 3D computed tomography (CT) data to verify lead placement during stereotactic robot assisted surgery. Accuracy of lead localization determined from 2D 3D registration was compared to conventional 3D 3D registration in a subsequent patient study. The mean Euclidian distance of lead coordinates estimated from intensity-based 2D 3D registration versus flat-panel detector CT 3D 3D registration was 0.7 mm ± 0.2 mm. Maximum values of these distances amounted to 1.2 mm. To further investigate 2D 3D registration a simulation study was conducted, challenging two observers to visually assess artificially generated 2D 3D registration errors. 95% of deviation simulations, which were visually assessed as sufficient, had a registration error below 0.7 mm.In conclusion, 2D 3D intensity-based registration revealed high accuracy and reliability during robot guided stereotactic neurosurgery and holds great potential as a low dose, cost effective means for intraoperative lead localization.

Feasibility of Flat Panel Detector CT in Perfusion Assessment of Brain Arteriovenous Malformations: Initial Clinical Experience.

The different results from flat panel detector CT in various pathologies have provoked some discussion. Our aim was to assess the role of flat panel detector CT in brain arteriovenous malformations, which has not yet been assessed. Five patients with brain arteriovenous malformations were studied with flat panel detector CT, DSC-MR imaging, and vessel-encoded pseudocontinuous arterial spin-labeling. In glomerular brain arteriovenous malformations, perfusion was highest next to the brain arteriovenous malformation with decreasing values with increasing distance from the lesion. An inverse tendency was observed in the proliferative brain arteriovenous malformation. Flat panel detector CT, originally thought to measure blood volume, correlated more closely with arterial spin-labeling-CBF and DSC-CBF than with DSC-CBV. We conclude that flat panel detector CT perfusion depends on the time point chosen for data collection, which is triggered too early in these patients (ie, when contrast agent appears in the superior sagittal sinus after rapid shunting through the brain arteriovenous malformation). This finding, in combination with high data variability, makes flat panel detector CT inappropriate for perfusion assessment in brain arteriovenous malformations.