scholarly journals Cerebral CT Perfusion in Acute Stroke: The Effect of Lowering the Tube Load and Sampling Rate on the Reproducibility of Parametric Maps

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1121
Author(s):  
Georgios S. Ioannidis ◽  
Søren Christensen ◽  
Katerina Nikiforaki ◽  
Eleftherios Trivizakis ◽  
Kostas Perisinakis ◽  
...  
Keyword(s):  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Sampling Rate ◽  
Volumetric Analysis ◽  
Sampling Interval ◽  
Diagnostic Efficiency ◽  
Temporal Sampling ◽  
Sampling Intervals ◽  
The Mean ◽  
Parametric Maps

The aim of this study was to define lower dose parameters (tube load and temporal sampling) for CT perfusion that still preserve the diagnostic efficiency of the derived parametric maps. Ninety stroke CT examinations from four clinical sites with 1 s temporal sampling and a range of tube loads (mAs) (100–180) were studied. Realistic CT noise was retrospectively added to simulate a CT perfusion protocol, with a maximum reduction of 40% tube load (mAs) combined with increased sampling intervals (up to 3 s). Perfusion maps from the original and simulated protocols were compared by: (a) similarity using a voxel-wise Pearson’s correlation coefficient r with in-house software; (b) volumetric analysis of the infarcted and hypoperfused volumes using commercial software. Pearson’s r values varied for the different perfusion metrics from 0.1 to 0.85. The mean slope of increase and cerebral blood volume present the highest r values, remaining consistently above 0.7 for all protocol versions with 2 s sampling interval. Reduction of the sampling rate from 2 s to 1 s had only modest impacts on a TMAX volume of 0.4 mL (IQR −1–3) (p = 0.04) and core volume of −1.1 mL (IQR −4–0) (p < 0.001), indicating dose savings of 50%, with no practical loss of diagnostic accuracy. The lowest possible dose protocol was 2 s temporal sampling and a tube load of 100 mAs.

Abstract 3268: Ct Perfusion As A Tool To Predict The Risk Of Hemorrhagic Transformation In Ischemic Stroke Treated With Tissue Plasminogen Activator: A Single Center Experience.

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Tareq Kass-Hout ◽  
Maxim Mokin ◽  
Omar Kass-Hout ◽  
Emad Nourollahzadeh ◽  
David Wack ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Stroke ◽  
Brain Tissue ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Intravenous Thrombolysis ◽  
Hemorrhagic Transformation ◽  
Stroke Therapy ◽  
Two Phase ◽  
The Mean

Objective: To use the Computed Tomography Perfusion (CTP) parameters at the time of hospital admission, including Cerebral Blood Volume (CBV) and Permeability Surface area product (PS), to identify patients with higher risk to develop hemorrhagic transformation in the setting of acute stroke therapy with intravenous thrombolysis. Methods: Retrospective study that compared admission CTP variables between patients with Hemorrhagic Transformation (HT) acute stroke and those with no hemorrhagic transformation. Both groups received standard of care intravenous thrombolysis with tPA. Twenty patients presented to our stroke center between the years 2007 - 2011 within 3 hours after stroke symptoms onset. All patients underwent two-phase 320 slice CTP which creates CBV and PS measurements. Patients were divided into two groups according to whether or not they had HT on a follow up CT head without contrast, done within 36 hours of the thrombolysis therapy. Clinical, demographic and CTP variables were compared between the HT and non-HT groups using logistic regression analyses. Results: HT developed in 8 (40%) patients. Patients with HT had lower ASPECT score ( P =.03), higher NIHSS on admission ( P= .01) and worse outcome ( P= .04) compared to patients who did not develop HT. Baseline blood flow defects were comparable between the two groups. The mean PS for the HT group was 0.53 mL/min/100g brain tissue, which was significantly higher than that for the non-HT group of 0.04 mL/min/100g brain tissue ( P <.0001). The mean area under the curve was 0.92 (95% CI). The PS threshold of 0.26 mL/min/100g brain tissue had a sensitivity of 80% and a specificity of 92% for detecting patients with high risk of hemorrhagic transformation after intravenous thrombolysis. Conclusions: Admission CTP measurements might be useful to predict patients who are at higher risk to develop hemorrhagic transformation after acute ischemic stroke therapy.

Three-Dimensional Wheel Topography Measurement with Laser Triangulation

2012 ◽  
Vol 499 ◽  
pp. 384-389 ◽  
Author(s):  
Jia Liu ◽  
Wu Yi Chen ◽  
F. Chen
Keyword(s):  
Standard Deviation ◽  
Three Dimensional ◽  
Sampling Interval ◽  
Laser Triangulation ◽  
Evaluation Indexes ◽  
Wheel Topography ◽  
Sampling Intervals ◽  
Optimum Sampling ◽  
The Mean ◽  
Vitrified Cbn

Laser triangulation was used to measure the topography of vitrified CBN wheels and optimum sampling interval was obtained by comparing measuring results with different sampling intervals. Four evaluation indexes including the mean protrusion height of abrasive grains Hm, the standard deviation of grain protrusion height Hv, the standard deviation of the distance between two adjacent grains Dv and the number of micro cutting edges per square millimeter Nm were put forward to assess wheel topography and grinding performance. These indexes were verified to be effective by comparing 3D topography of newly manufactured wheel and dressed wheel.

scholarly journals CT Perfusion Imaging Improves Infarct Conspicuity in Hyperacute Stroke

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 325-325
Author(s):  
Peter Bove ◽  
Michael H Lev ◽  
Dmetri Berdichevsky ◽  
Gordon J Harris ◽  
Nathaniel M Alpert ◽  
...  
Keyword(s):  
Ct Angiography ◽  
Blood Volume ◽  
Gray Matter ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Blood Pool ◽  
Hyperacute Stroke ◽  
Tissue Edema ◽  
The Mean ◽  
Volume Ct

51 Purpose: To compare infarct conspicuity and image quality of noncontrast CT (NCCT), CT perfusion (CTP), and CT subtraction cerebral blood volume (CT-CBV) images of patients with hyperacute stroke. Background: NCCT is typically the first imaging test obtained in the evaluation of acute stroke. Whole brain CTP imaging is performed, simultaneously with CT angiography, during the steady state administration of IV contrast. Subtraction of coregistered NCCT images from the CTP images yields maps of perfused blood volume (CT-CBV). Ischemic areas on each of the NCCT, CTP, and CT-CBV images appear as hypodense, low attenuation regions. Materials and Methods: We reviewed the images of 20 consecutive patients with MCA stem occlusion who underwent intra-arterial thrombolysis within 6 hours of stroke onset. All had NCCT and CT angiography with CTP imaging prior to thrombolysis. Subtraction CT-CBV maps were created and analyzed using proprietary software (IMIPS, Inc). For each of the NCCT, CTP, and CT-CBV images, infarct conspicuity was defined by dividing the mean attenuation difference between normal and maximally hypodense gray matter by the mean normal gray matter attenuation. Contrast-to-noise ratio (CNR) was defined by dividing the same numerator by the standard deviation of the normal gray matter attenuation values. Statistical analysis was by ANOVA and students t-test. Results: Overall infarct conspicuity was 0.11 for the NCCT, 0.22 for the CTP, and 0.98 for the CT-CBV images (p<0.003 for all maps). Mean CNR was 0.95 for the NCCT, 1.94 for the CTP, and 1.12 for the CT-CBV images (p<0.01, for the CTP maps only). Conclusions: CT perfusion and CT-CBV subtraction imaging improve infarct conspicuity over that of NCCT in patients with hyperacute stroke. True reduction in blood pool (as reflected by CT-CBV), rather than increase in tissue edema (as reflected by NCCT), may explain much of the improved infarct delineation in CTP imaging. Because CNR is greater for CTP than for subtraction images, concurrent review of NCCT, CTP, and CT-CBV images may be indicated for optimal CT assessment of hyperacute MCA stroke.

scholarly journals CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

2021 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Martin W. Huellner ◽  
Martin Banyai ◽  
Sebastian Mafeld ◽  
Johannes Heverhagen ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Ct Perfusion ◽  
Arterial Disease ◽  
Lower Leg ◽  
Therapy Control ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
The Mean ◽  
Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

scholarly journals Intravenous Edaravone plus Therapeutic Hypothermia Offers Limited Neuroprotection in the Hypoxic-Ischaemic Newborn Piglet

Neonatology ◽  
2020 ◽  
pp. 1-8
Author(s):  
Satoshi Hamano Yamato ◽  
Shinji Nakamura ◽  
Yinmon Htun ◽  
Makoto Nakamura ◽  
Wataru Jinnai ◽  
...  
Keyword(s):  
Therapeutic Hypothermia ◽  
Cerebral Blood Volume ◽  
Free Radical Scavenger ◽  
Newborn Piglet ◽  
Radical Scavenger ◽  
Neuroprotective Effects ◽  
The Mean ◽  
Additional Therapy ◽  
Inspired Oxygen ◽  
Histopathological Score

<b><i>Background:</i></b> Therapeutic hypothermia (TH) is a standard therapy for neonatal hypoxic-ischaemic encephalopathy. One potential additional therapy is the free radical scavenger edaravone (EV; 3-methyl-1-phenyl-2-pyrazolin-5-one). <b><i>Objectives and Methods:</i></b> This study aimed to compare the neuroprotective effects of edaravone plus therapeutic hypothermia (TH + EV) with those of TH alone after a hypoxic-ischaemic insult in the newborn piglet. Anaesthetized piglets were subjected to 40 min of hypoxia (3–5% inspired oxygen), and cerebral ischaemia was assessed using cerebral blood volume. Body temperature was maintained at 39.0 ± 0.5°C in the normothermia group (NT, <i>n</i> = 8) and at 33.5 ± 0.5°C (24 h after the insult) in the TH (<i>n</i> = 7) and TH + EV (3 mg/kg intravenous every 12 h for 3 days after the insult; <i>n</i> = 6) groups under mechanical ventilation. <b><i>Results:</i></b> Five days after the insult, the mean (standard deviation) neurological scores were 10.9 (5.7) in the NT group, 17.0 (0.4) in the TH group (<i>p</i> = 0.025 vs. NT), and 15.0 (3.9) in the TH + EV group. The histopathological score of the TH + EV group showed no significant improvement compared with that of the other groups. <b><i>Conclusion:</i></b> TH + EV had no additive neuroprotective effects after hypoxia-ischaemia in neurological and histopathological assessments.

scholarly journals 3D Volumetric Analysis and Anatomical Considerations for Sinus Bone Graft

2021 ◽  
Vol 11 (3) ◽  
pp. 951
Author(s):  
Ji Hyoung Kim ◽  
Hyo Joon Kim ◽  
Ye Joon Jo ◽  
Jun Seok Choi ◽  
Seong Yong Moon
Keyword(s):  
Bone Graft ◽  
Maxillary Sinus ◽  
Alveolar Bone ◽  
Lateral Wall ◽  
Volumetric Analysis ◽  
Ct Scans ◽  
Sinus Floor Elevation ◽  
Sinus Wall ◽  
Sinus Floor ◽  
The Mean

The aim of this study is to evaluate anatomical considerations and assess the volume of the maxillary sinus bone graft. There were sixty-three patients (eighty-three sinuses) who had taken CT scans for implant surgery. Patients included those whose height of the residual alveolar bone was less than 5 mm. The position of posterior superior alveolar artery, the thickness of the maxillary sinus wall, and the volume of the maxillary sinus according to the amount of sinus floor elevation were measured. The mean vertical distance of posterior superior alveolar artery was 11.91 ± 4.79 mm from 3.03 mm to 24.05 mm. The mean thickness of the lateral wall was 1.71 ± 0.55 mm in the range of 0.74 mm to 3.93 mm. The volume of 3 mm, 5 mm, 7 mm, and 10 mm from the sinus floor was 0.173 ± 0.11 cm3, 0.526 ± 0.25 cm3, 1.068 ± 0.43 cm3, and 2.184 ± 0.74 cm3 on average, respectively. The knowledge of the posterior superior alveolar artery position, the lateral wall thickness, and the volume of the maxillary sinus can help the clinician for sinus bone graft.

Non-invasive assessment of heterogeneity of gliomas using diffusion and perfusion MRI: correlation with spatially co-registered PET

2021 ◽  
pp. 028418512110069
Author(s):  
Ying Zhang ◽  
Yu Lin ◽  
Zhen Xing ◽  
Shaobo Yao ◽  
Dairong Cao ◽  
...  
Keyword(s):  
Tissue Characterization ◽  
Cerebral Blood Volume ◽  
T Test ◽  
Perfusion Mri ◽  
Perfusion Magnetic Resonance Imaging ◽  
Diagnostic Efficiency ◽  
Who Grade ◽  
Non Invasive ◽  
Glioma Grading ◽  
Relative Minimum

Background Heterogeneity of gliomas challenges the neuronavigated biopsy and oncological therapy. Diffusion and perfusion magnetic resonance imaging (MRI) can reveal the cellular and hemodynamic heterogeneity of tumors. Integrated positron emission tomography (PET)/MRI is expected to be a non-invasive imaging approach to characterizing glioma. Purpose To evaluate the value of apparent diffusion coefficient (ADC), cerebral blood volume (CBV), and spatially co-registered maximal standard uptake value (SUVmax) for tissue characterization and glioma grading. Material and Methods Thirty-seven consecutive patients with pathologically confirmed gliomas were retrospectively investigated. The relative minimum ADC (rADCmin), relative maximal ADC (rADCmax), relative maximal rCBV (rCBVmax), the relative minimum rCBV (rCBVmin), and the corresponding relative SUVmax (rSUVmax) were measured. The paired t-test was used to compare the quantitative parameters between different regions to clarify tumor heterogeneity. Imaging parameters between WHO grade IV and grade II/III gliomas were compared by t-test. The diagnostic efficiency of multiparametric PET/MRI was analyzed by receiver operating characteristic (ROC) curve. Results The values of rSUVmax were significantly different between maximal diffusion/perfusion area and minimum diffusion/perfusion area ( P < 0.001/ P < 0.001) within tumor. The values of rADCmin ( P < 0.001), rCBVmax ( P = 0.002), and corresponding rSUVmax ( P = 0.001/ P < 0.001) could be used for grading gliomas. The areas under the ROC curves of rSUVmax defined by rADCmin and rCBVmax were 0.89 and 0.91, respectively. Conclusion Diffusion and perfusion MRI can detect glioma heterogeneity with excellent molecular imaging correlations. Regions with rCBVmax suggest tissues with the highest metabolism and malignancy for guiding glioma grading and tissue sampling.

Optimizing Outcomes in Neck Lift Surgery

2021 ◽  
Author(s):  
Thomas Gerald O’Daniel
Keyword(s):  
Surgical Planning ◽  
Planning Process ◽  
Objective Evaluation ◽  
Volumetric Analysis ◽  
Anterior Neck ◽  
Surgical Specimen ◽  
Neck Lift ◽  
Fat Reduction ◽  
The Mean ◽  
The Impact

Abstract Background In certain patients there is an imbalance between the volume of the anterior neck and the mandibular confines that require reductional sculpting and repositioning of the hyoid to optimize neck lifting procedures. Objectives A quantitative volumetric analysis of impact of the management of supraplatysmal and subplatysmal structures of the neck by comparing surgical specimen was performed to determine the impact of reduction on cervical contouring. Methods In 152 patients undergoing deep cervicoplasty, the frequency of modification of each surgical maneuver and amount of supraplatysmal and subplatysmal volume removed was measured in cubic centimeters using a volume displacement technique. Results The mean volume of total volume remove from the supraplatysmal and subplatysmal planes during deep cervicoplasty was 22.3 cm3 with subplatysmal volume representing 73%. Subplatysmal volume was reduced in 152 patients. Deep fat was reduced in 96% of patients with mean volume of 7 cm3, submandibular glands (76%) with mean volume 6.5cm, anterior digastric muscles (70%) with mean volume 2cm3, peri-hyoid fascia (32%) with mean volume &lt;1cm3 and mylohyoid reduction (14%) with mean volume &lt; 1cm3 in the series. The anterior digastric muscles were plicated to reposition the hyoid in 34% of cases. Supraplatysmal fat reduction was 6.3 cm3 in 40% of patients. Conclusions The study provides a comprehensive analysis of the impact of volume modification of the central neck during deep cervicoplasty. This objective evaluation of neck volume may help guide clinicians in the surgical planning process and provide a foundation for optimizing cervicofacial rejuvenation techniques.

Volumetric quantification of aneurysmal subarachnoid hemorrhage independently predicts hydrocephalus and seizures

2021 ◽  
pp. 1-9
Author(s):  
Badih J. Daou ◽  
Siri Sahib S. Khalsa ◽  
Sharath Kumar Anand ◽  
Craig A. Williamson ◽  
Noah S. Cutler ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Characteristic Curve ◽  
Volumetric Analysis ◽  
Aneurysm Rupture ◽  
Mean Difference ◽  
Analysis Tool ◽  
Volume Data ◽  
Hemorrhage Volume ◽  
The Mean

OBJECTIVEHydrocephalus and seizures greatly impact outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH); however, reliable tools to predict these outcomes are lacking. The authors used a volumetric quantitative analysis tool to evaluate the association of total aSAH volume with the outcomes of shunt-dependent hydrocephalus and seizures.METHODSTotal hemorrhage volume following aneurysm rupture was retrospectively analyzed on presentation CT imaging using a custom semiautomated computer program developed in MATLAB that employs intensity-based k-means clustering to automatically separate blood voxels from other tissues. Volume data were added to a prospectively maintained aSAH database. The association of hemorrhage volume with shunted hydrocephalus and seizures was evaluated through logistic regression analysis and the diagnostic accuracy through analysis of the area under the receiver operating characteristic curve (AUC).RESULTSThe study population comprised 288 consecutive patients with aSAH. The mean total hemorrhage volume was 74.9 ml. Thirty-eight patients (13.2%) developed seizures. The mean hemorrhage volume in patients who developed seizures was significantly higher than that in patients with no seizures (mean difference 17.3 ml, p = 0.01). In multivariate analysis, larger hemorrhage volume on initial CT scan and hemorrhage volume > 50 ml (OR 2.81, p = 0.047, 95% CI 1.03–7.80) were predictive of seizures. Forty-eight patients (17%) developed shunt-dependent hydrocephalus. The mean hemorrhage volume in patients who developed shunt-dependent hydrocephalus was significantly higher than that in patients who did not (mean difference 17.2 ml, p = 0.006). Larger hemorrhage volume and hemorrhage volume > 50 ml (OR 2.45, p = 0.03, 95% CI 1.08–5.54) were predictive of shunt-dependent hydrocephalus. Hemorrhage volume had adequate discrimination for the development of seizures (AUC 0.635) and shunted hydrocephalus (AUC 0.629).CONCLUSIONSHemorrhage volume is an independent predictor of seizures and shunt-dependent hydrocephalus in patients with aSAH. Further evaluation of aSAH quantitative volumetric analysis may complement existing scales used in clinical practice and assist in patient prognostication and management.

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