scholarly journals Breath-Hold Induced Cerebrovascular Reactivity Measurements Using Optimized Pseudocontinuous Arterial Spin Labeling

2021 ◽  
Vol 12 ◽  
Author(s):  
Sergio M. Solis-Barquero ◽  
Rebeca Echeverria-Chasco ◽  
Marta Calvo-Imirizaldu ◽  
Elena Cacho-Asenjo ◽  
Antonio Martinez-Simon ◽  
...  
Keyword(s):  
Arterial Spin Labeling ◽  
Free Breathing ◽  
Physiological Model ◽  
Spin Labeling ◽  
Cerebrovascular Reactivity ◽  
Breath Holding ◽  
Breath Hold ◽  
Background Suppression ◽  
Single Shot ◽  
Scan Time

A pseudocontinuous arterial spin labeling (PCASL) sequence combined with background suppression and single-shot accelerated 3D RARE stack-of-spirals was used to evaluate cerebrovascular reactivity (CVR) induced by breath-holding (BH) in ten healthy volunteers. Four different models designed using the measured change in PETCO2 induced by BH were compared, for CVR quantification. The objective of this comparison was to understand which regressor offered a better physiological model to characterize the cerebral blood flow response under BH. The BH task started with free breathing of 42 s, followed by interleaved end-expiration BHs of 21 s, for ten cycles. The total scan time was 12 min and 20 s. The accelerated readout allowed the acquisition of PCASL data with better temporal resolution than previously used, without compromising the post-labeling delay. Elevated CBF was observed in most cerebral regions under hypercapnia, which was delayed with respect to the BH challenge. Significant statistical differences in CVR were obtained between the different models in GM (p < 0.0001), with ramp models yielding higher values than boxcar models and between the two tissues, GM and WM, with higher values in GM, in all the models (p < 0.0001). The adjustment of the ramp amplitude during each BH cycle did not improve the results compared with a ramp model with a constant amplitude equal to the mean PETCO2 change during the experiment.

scholarly journals Comparison of Compressed Sensing and Gradient and Spin-Echo in Breath-Hold 3D MR Cholangiopancreatography: Qualitative and Quantitative Analysis

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 634
Author(s):  
Weon Jang ◽  
Ji Soo Song ◽  
Sang Heon Kim ◽  
Jae Do Yang
Keyword(s):  
Image Quality ◽  
Compressed Sensing ◽  
Spin Echo ◽  
Contrast Ratio ◽  
Rank Test ◽  
Breath Holding ◽  
Breath Hold ◽  
Background Suppression ◽  
Time Saving ◽  
Noise Ratio

While magnetic resonance cholangiopancreatography (MRCP) is routinely used, compressed sensing MRCP (CS-MRCP) and gradient and spin-echo MRCP (GRASE-MRCP) with breath-holding (BH) may allow sufficient image quality with shorter acquisition times. This study qualitatively and quantitatively compared BH-CS-MRCP and BH-GRASE-MRCP and evaluated their clinical effectiveness. Data from 59 consecutive patients who underwent both BH-CS-MRCP and BH-GRASE-MRCP were qualitatively analyzed using a five-point Likert-type scale. The signal-to-noise ratio (SNR) of the common bile duct (CBD), contrast-to-noise ratio (CNR) of the CBD and liver, and contrast ratio between periductal tissue and the CBD were measured. Paired t-test, Wilcoxon signed-rank test, and McNemar’s test were used for statistical analysis. No significant differences were found in overall image quality or duct visualization of the CBD, right and left 1st level intrahepatic duct (IHD), cystic duct, and proximal pancreatic duct (PD). BH-CS-MRCP demonstrated higher background suppression and better visualization of right (p = 0.004) and left 2nd level IHD (p < 0.001), mid PD (p = 0.003), and distal PD (p = 0.041). Image quality degradation was less with BH-GRASE-MRCP than BH-CS-MRCP (p = 0.025). Of 24 patients with communication between a cyst and the PD, 21 (87.5%) and 15 patients (62.5%) demonstrated such communication on BH-CS-MRCP and BH-GRASE-MRCP, respectively. SNR, contrast ratio, and CNR of BH-CS-MRCP were higher than BH-GRASE-MRCP (p < 0.001). Both BH-CS-MRCP and BH-GRASE-MRCP are useful imaging methods with sufficient image quality. Each method has advantages, such as better visualization of small ducts with BH-CS-MRCP and greater time saving with BH-GRASE-MRCP. These differences allow diverse choices for visualization of the pancreaticobiliary tree in clinical practice.

scholarly journals Quantitative single breath-hold renal arterial spin labeling imaging at 7T

2017 ◽  
Vol 79 (2) ◽  
pp. 815-825 ◽  
Author(s):  
Xiufeng Li ◽  
Edward J. Auerbach ◽  
Pierre-Francois Van de Moortele ◽  
Kamil Ugurbil ◽  
Gregory J. Metzger
Keyword(s):  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Breath Hold ◽  
Single Breath ◽  
Single Breath Hold

Abstract 15240: Evaluation of the Performance and Safety of Wideband Cardiac MRI in Patients With a Cardiac Implantable Electronic Device (CIED)

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sarah M Schwartz ◽  
Ashitha Pathrose ◽  
Ali Serhal ◽  
Ryan Avery ◽  
Ann Ragin ◽  
...  
Keyword(s):  
Image Quality ◽  
Electronic Device ◽  
Pulse Sequences ◽  
Free Breathing ◽  
Whole Body ◽  
Breath Hold ◽  
Single Shot ◽  
Before And After ◽  
Order Of Magnitude ◽  
Chest X Ray

Introduction: Wideband late gadolinium enhancement (LGE) CMR is capable of suppressing image artifacts induced by cardiac implanted electronic devices (CIEDs). We implemented our own wideband segmented (seg) breath-hold and wideband single-shot (SS) free-breathing LGE pulse sequences and used them clinically since 2016. The purpose of this study was to evaluate image quality and CMR safety of wideband LGE compared to standard LGE. Methods: We retrospectively identified 54 consecutive patients (mean age: 61±15 years; 31% females) with CIED (33 t-ICD, 4 s-ICD, 15 pacemaker, 1 CRT-D, 1 CRT-P) who underwent CMR at 1.5T (Avanto, Siemens). Standard seg, wideband seg, and wideband SS LGE used standard imaging parameters. 16 myocardial segments were scored for scar/myocardial conspicuity and presence of any visual artifact on a 5-point Likert scale (1:worst; 3:acceptable; 5:best). Distance between center of the heart and CIED (CXR D) was measured on chest X-ray. Whole-body specific absorption rate (SAR) was read from DICOM metadata. Device changes were calculated from pre- and post- device interrogation measurements. Results: Both wideband seg and SS LGE consistently produced better image quality than standard LGE (Figure 1A). Median conspicuity and artifact scores were significantly better for wideband seg (F=20.6, p<0.001) and wideband SS (F=24.2, p<0.001) LGE compared to standard LGE. There was a trend in conspicuity and artifact scores with CIED distance for standard LGE (rho=0.476, p=0.02), but not wideband LGE scans (Figure 1B, 1C). Whole-body SAR averaged for both wideband scans (0.15±0.04 W/kg) was one order of magnitude below the 2.0 W/kg FDA limit. Device parameters (sensing, impedance, threshold, battery level) did not differ before and after CMR including wideband LGE. Conclusions: Both wideband seg and SS LGE scans produced improved image quality compared to standard LGE while maintaining CMR safety. *The first two authors (SS and AP) contributed equally

scholarly journals Arterial Spin Labeling and Blood Oxygen Level-Dependent MRI Cerebrovascular Reactivity in Cerebrovascular Disease: A Systematic Review and Meta-Analysis

2016 ◽  
Vol 42 (3-4) ◽  
pp. 288-307 ◽  
Author(s):  
Diederik P.J. Smeeing ◽  
Jeroen Hendrikse ◽  
Esben T. Petersen ◽  
Manus J. Donahue ◽  
Jill B. de Vis
Keyword(s):  
Cerebrovascular Disease ◽  
Arterial Spin Labeling ◽  
Meta Analysis ◽  
Spin Labeling ◽  
Blood Oxygen Level Dependent ◽  
Cerebrovascular Reactivity ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Occlusive Vascular Disease

Background: The cerebrovascular reactivity (CVR) results of blood oxygen level-dependent (BOLD) and arterial spin labeling (ASL) MRI studies performed in patients with cerebrovascular disease (steno-occlusive vascular disease or stroke) were systematically reviewed. Summary: Thirty-one articles were included. Twenty-three (74.2%) studies used BOLD MRI to evaluate the CVR, 4 (12.9%) studies used ASL MRI and 4 (12.9%) studies used both BOLD and ASL MRI. Thirteen studies (3 significant) found a lower BOLD CVR, 2 studies found a similar CVR and 3 studies found a higher CVR in the ipsilateral compared to the contralateral hemisphere. Nine (5 significant) out of 10 studies found a lower BOLD CVR in the ipsilateral hemispheres of patients compared to controls. Six studies (2 significant) found a lower ASL CVR in the ipsilateral compared to the contralateral hemispheres. Three out of 5 studies found a significant lower ASL CVR in the ipsilateral hemispheres of patients compared to controls. Key Messages: This review brings support for a reduced BOLD and ASL CVR in the ipsilateral hemisphere of patients with cerebrovascular disease. We suggest that future studies will be performed in a uniform way so reference values can be established and could be used to guide treatment decisions in patients with cerebrovascular disease.

scholarly journals Intra- and Multicenter Reproducibility of Pulsed, Continuous and Pseudo-Continuous Arterial Spin Labeling Methods for Measuring Cerebral Perfusion

2011 ◽  
Vol 31 (8) ◽  
pp. 1706-1715 ◽  
Author(s):  
Sanna Gevers ◽  
Matthias J van Osch ◽  
Reinoud PH Bokkers ◽  
Dennis A Kies ◽  
Wouter M Teeuwisse ◽  
...  
Keyword(s):  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Repeated Measurements ◽  
Background Suppression ◽  
Regional Variability ◽  
Clinical Routine ◽  
Imaging Protocol ◽  
Cerebral Pathology ◽  
Continuous Arterial Spin Labeling ◽  
Healthy Participants

Intra- and multicenter reproducibility of currently used arterial spin labeling (ASL) methods were assessed at three imaging centers in the Netherlands, equipped with Philips 3TMR scanners. Six healthy participants were scanned twice at each site. The imaging protocol consisted of continuous ASL (CASL), pseudo-continuous ASL (p-CASL) with and without background suppression, pulsed ASL (PASL) with single and multiple inversion times (TIs), and selective ASL for segmentation. Reproducibility was expressed in terms of the coefficient of repeatability and the repeatability index. Voxelwise analysis of variance was performed, yielding brain maps that reflected regional variability. Intra- and multicenter reproducibility were comparable for all methods, except for single TI PASL, with better intracenter reproducibility (F-test of equality of two variances, P < 0.05). Pseudo-continuous ASL and multi TI PASL varied least between sites. Variability maps of all methods showed most variability near brain-feeding arteries within sessions and in gray matter between sessions. On the basis of the results of this study, one could consider the use of reference values in clinical routine, with whole-brain p-CASL perfusion varying < 20% over repeated measurements within the same individuals considered to be normal. Knowledge on regional variability allows for the use of perfusion-weighted images in the assessment of local cerebral pathology.

scholarly journals Cerebrovascular reactivity assessment with O2-CO2 exchange ratio under brief breath hold challenge

2019 ◽  
Author(s):  
Suk Tak Chan ◽  
Karleyton C. Evans ◽  
Tian Yue Song ◽  
Juliett Selb ◽  
Andre van der Kouwe ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Partial Pressure ◽  
Cerebral Arteries ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Breath Holding ◽  
Breath Hold ◽  
Bold Signal ◽  
Signal Changes

AbstractHypercapnia during breath holding is believed to be the dominant driver behind the modulation of cerebral blood flow (CBF). Here we showed that the cerebrovascular responses to brief breath hold epochs were coupled not only with increased partial pressure of carbon dioxide (PCO2), but also with a decrease in partial pressure of oxygen (PO2). We used transcranial Doppler ultrasound to evaluate the CBF changes during breath holding by measuring the cerebral blood flow velocity (CBFv) in the middle cerebral arteries, a pair of cerebral arteries that supply most parts of the brain. The regional CBF changes during breath hold epochs were mapped with blood oxygenation level dependent (BOLD) signal changes as surrogate of CBF changes using functional magnetic resonance imaging (fMRI) technique. Given the interdependence of the dynamic changes between PCO2 and PO2, we found that the breath-by-breath O2-CO2 exchange ratio (bER), namely the ratio of changes in PO2 (ΔPO2) to changes in PCO2 (ΔPCO2) between end inspiration and end expiration, was superior to either ΔPO2 or ΔPCO2 alone in coupling with the changes of CBFv and BOLD signals under breath hold challenge. The regional cerebrovascular reactivity (CVR) results derived by regressing BOLD signal changes on bER under breath hold challenge resembled those derived by regressing BOLD signal changes on end-tidal partial pressure of CO2 (PETCO2) under exogenous CO2 challenge. Our findings provide a novel insight on the potential of using bER to better quantify CVR changes under breath hold challenge, although the physiological mechanisms of cerebrovascular changes underlying breath hold and exogenous CO2 challenges are potentially different.

Abstract MP42: Arterial Spin Labeling Imaging Assessment of Cerebrovascular Reactivity in Hypertensive Small Vessel Disease

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Hsin-Hsi C Tsai ◽  
Bo-Ching Lee ◽  
Abel Po-Hao Huang ◽  
Li-Kai Tsai ◽  
Ya-Fang Chen ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Arterial Spin Labeling ◽  
Small Vessel Disease ◽  
Vascular Dysfunction ◽  
Spin Labeling ◽  
Cerebrovascular Reactivity ◽  
Small Vessel ◽  
Disease Score ◽  
Temporal Lobes ◽  
Vessel Disease

Objective: Cerebrovascular reactivity (CVR) represents the phenomenon that cerebral vessels dilate or constrict in response to vasoactive stimuli, and CVR impairment may contribute to the brain injury caused by cerebral small vessel disease (SVD). We aim to determine the CVR in hypertensive intracerebral hemorrhage (ICH) and to identify its vascular dysfunction. Methods: 21 patients with spontaneous hypertensive ICH (strictly deep or mixed deep and lobar hemorrhages, mean age 62.5 ± 11.3 years) and 10 control subjects (mean age 66.1 ± 6.0) were enrolled for CVR measurement. Each participant received a brain MRI study, and CVR was calculated as cerebral blood flow (CBF) change using arterial spin labeling (ASL) sequence at baseline and 10 minutes after intravenous dipyridamole injection (0.57mg/Kg). Traditional MRI markers for SVD including cerebral microbleed, white matter hyperintensity, lacune and MRI-visible enlarged perivascular space were also evaluated to determine the total small vessel disease score. Results: Hypertensive ICH patients showed reduced CVR in the basal ganglia (CBF change 22.4 ± 22.7% vs. 41.7 ± 18.3, p=0.026), the frontal (15.1 ± 11.9 vs. 26.6 ± 9.9, p=0.013) and the temporal lobes (14.7 ± 11.1 vs. 26.2 ± 10.0, p=0.010) compared to control subjects (Figure). These differences remained significant in multivariable models after adjusting for age, sex, hypertension, diabetes, and hyperlipidemia. Within ICH groups, the CBF change in basal ganglia was significantly correlated with total small vessel disease score (R=-0.58, p=0.006), but not with individual MRI markers. Conclusion: Patients with advanced HTN-SVD demonstrated impaired vasoconstriction after dipyridamole challenge in basal ganglia, frontal and temporal lobes. Our findings provide safe approaches for whole brain CVR mapping in small vessel disease, and identify the potential physiological basis of vascular dysfunction in HTN-SVD.

Abstract W MP114: Arterial Spin Label Perfusion Imaging in Acute Neonatal Stroke Reveals Hyperperfusion in Association With Cerebral Ischemic Injury

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Michael J Rivkin ◽  
Christopher G Watson ◽  
Mathieu Dehaes ◽  
Borjan A Gagoski ◽  
P. E Grant
Keyword(s):  
Acute Stroke ◽  
Arterial Spin Labeling ◽  
Ischemic Injury ◽  
Spin Labeling ◽  
Arterial Spin Label ◽  
Regional Perfusion ◽  
Perfusion Magnetic Resonance Imaging ◽  
Arterial Ischemic Stroke ◽  
Neonatal Stroke ◽  
Scan Time

Introduction: Perfusion magnetic resonance imaging (pMRI) in adults reveals a hypoperfused region, the ischemic penumbra, related to the fixed ischemic injury shown by diffusion weighted imaging (DWI) in acute stroke. Neonatal stroke has pathophysiology and optimum treatment that remain elusive. We hypothesized that altered regional perfusion accompanies the ischemic injury in focal neonatal stroke. Methods: Neonates (0-28 days of life) underwent MR imaging at 3T fieldstrength. pMRI employed a pseudocontinuous arterial spin labeling (PCASL) sequence with multi-slice echo planar readouts at 3x3x5mm3 resolution with TE/TR = 12ms/3.5s, labeling time = 1.6s, a post-labeling delay = 1.5s, 9 axial slices acquired, scan time ~5 min. Forty label/control image pairs were acquired, subtracted and averaged to obtain contrast maps proportional to quantified cerebral blood flow (CBF). DWI, susceptibility weighted imaging and T2-weighted series were obtained with standard protocols. Acute stroke was classified as arterial or venous. Core infarction was considered to lie in hypointense regions on DWI apparent diffusion coefficient maps. Regional perfusion signal was compared to the ischemic core on DWI and to the homologous uninvolved region in the contralesional hemisphere. Results: Data were collected on 20 neonates, (13 males; median/mean gestational age=38/38.5 weeks) with acute stroke (11 arterial ischemic stroke (AIS); 9 venous) scanned at median postnatal age=1.5 days. Evidence of regional hyperperfusion existed in 10/11 (91%) neonates with AIS and 4/9 (44%) with venous stroke. Hyperperfusion was part of a heterogeneous pattern of hypo- and hyperperfusion in 4 infants with AIS and 3 infants with venous infarct. Electroencephalography data obtained at presentation were available for 19 (95%) of the neonates. Fourteen infants (70%) had either electrographic seizure or focal sharp waves in the same hemisphere as the acute infarction. Conclusion: Arterial spin labeling pMRI can be successfully obtained in acute neonatal stroke. Unlike adults, pMRI often reveals hyperperfusion rather than hypoperfusion in neonates. This hyperperfusion may be due to early spontaneous reperfusion or to the neuronal hyperexcitability of stroke-associated seizure.

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