scholarly journals Perfusion Defects and Collateral Flow Patterns in Acute Small Subcortical Infarction: a 4D Dynamic MRI Study

2021 ◽  
Author(s):  
Yen-Chu Huang ◽  
Jiann-Der Lee ◽  
Yi-Ting Pan ◽  
Hsu-Huei Weng ◽  
Jen-Tsung Yang ◽  
...  
Keyword(s):  
Cerebral Blood Volume ◽  
Critical Role ◽  
Dynamic Mri ◽  
Cerebral Microbleeds ◽  
Perfusion Magnetic Resonance Imaging ◽  
Collateral Flow ◽  
Hemodynamic Changes ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Study ◽  
Subcortical Infarction

AbstractThe hemodynamic changes of acute small subcortical infarction (SSI) are not well understood. We evaluate the hemodynamic changes and collaterals in acute SSI using perfusion magnetic resonance imaging (MRI). A total of 103 patients with acute SSI in penetrating artery territories were recruited and underwent MRI within 24 h of stroke onset. Using 4D dynamic perfusion MRI, they were divided into three patterns: 25 (24%) with normal perfusion, 31 (30%) with compensated perfusion, and 47 (46%) with hypoperfusion. The development of anterograde or retrograde collaterals was also evaluated. Patients with hypoperfusion pattern had the highest rate of early neurological deterioration (32%, p = 0.007), the largest initial and final infarction volumes (p < 0.001 and p = 0.029), the lowest relative cerebral blood flow (0.63, p < 0.001), and the lowest rate of anterograde and retrograde collaterals (19%, p < 0.001; 66%, p = 0.002). The anterograde collaterals were associated with higher relative cerebral blood volume (0.91 vs. 0.77; p = 0.024) and a higher rate of deep cerebral microbleeds (48 vs. 21%; p = 0.028), whereas retrograde collaterals were associated with higher systolic and diastolic blood pressure (p = 0.031 and 0.020), smaller initial infarction volume (0.81 vs. 1.34 ml, p = 0.031), and a higher rate of lobar cerebral microbleeds (30 vs. 0%; p = 0.013). Both anterograde and retrograde collaterals may play a critical role in maintaining cerebral perfusion and can have an impact on patient clinical outcomes. Further studies are warranted to verify these findings and to investigate effective treatments.

scholarly journals Failure of Collateral Blood Flow is Associated with Infarct Growth in Ischemic Stroke

2013 ◽  
Vol 33 (8) ◽  
pp. 1168-1172 ◽  
Author(s):  
Bruce CV Campbell ◽  
Søren Christensen ◽  
Brian M Tress ◽  
Leonid Churilov ◽  
Patricia M Desmond ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Arterial Occlusion ◽  
Perfusion Magnetic Resonance Imaging ◽  
Lesion Volume ◽  
Collateral Flow ◽  
Collateral Blood Flow ◽  
Collateral Vessel ◽  
Magnetic Resonance Imaging Mri ◽  
Simultaneous Assessment

Changes in collateral blood flow, which sustains brain viability distal to arterial occlusion, may impact infarct evolution but have not previously been demonstrated in humans. We correlated leptomeningeal collateral flow, assessed using novel perfusion magnetic resonance imaging (MRI) processing at baseline and 3 to 5 days, with simultaneous assessment of perfusion parameters. Perfusion raw data were averaged across three consecutive slices to increase leptomeningeal collateral vessel continuity after subtraction of baseline signal analogous to digital subtraction angiography. Changes in collateral quality, Tmax hypoperfusion severity, and infarct growth were assessed between baseline and days 3 to 5 perfusion-diffusion MRI. Acute MRI was analysed for 88 patients imaged 3 to 6 hours after ischemic stroke onset. Better collateral flow at baseline was associated with larger perfusion-diffusion mismatch (Spearman's Rho 0.51, P < 0.001) and smaller baseline diffusion lesion volume (Rho − 0.70, P < 0.001). In 30 patients without reperfusion at day 3 to 5, deterioration in collateral quality between baseline and subacute imaging was strongly associated with absolute ( P = 0.02) and relative ( P < 0.001) infarct growth. The deterioration in collateral grade correlated with increased mean Tmax hypoperfusion severity (Rho − 0.68, P < 0.001). Deterioration in Tmax hypoperfusion severity was also significantly associated with absolute ( P = 0.003) and relative ( P = 0.002) infarct growth. Collateral flow is dynamic and failure is associated with infarct growth.

scholarly journals Prevalence of Cerebral Microbleeds in Thai Patients with Ischemic Stroke

2017 ◽  
Vol 08 (02) ◽  
pp. 216-220 ◽  
Author(s):  
Artit Potigumjon ◽  
Arvemas Watcharakorn ◽  
Pornpatr A. Dharmasaroja
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Magnetic Resonance ◽  
White Matter Lesions ◽  
Cerebral Microbleeds ◽  
National Institutes Of Health ◽  
Asian Origin ◽  
Chinese Study ◽  
Japanese Studies ◽  
Magnetic Resonance Imaging Mri

ABSTRACT Background: With the widespread use of magnetic resonance imaging (MRI), cerebral microbleeds (CMBs) are commonly detected. Ethnicity seems to play a role in the prevalence of CMB, with higher prevalence in participants from Asian origin. The purpose of the study is to look for the prevalence of CMBs and associated factors in Thai patients with ischemic stroke. Methods: Patients with acute ischemic stroke who had MRI and magnetic resonance angiography during January–August 2014 were included in the study. T2*-weighted gradient-recalled echo was used to define CMBs. Baseline characteristics, stroke subtypes, and severity of white matter lesions were compared between patients with and without CMBs. Results: Two hundred patients were included in the study. Mean age of the patients was 61-year-old. Mean National Institutes of Health Stroke Scale was 8. The prevalence of CMBs was 20% (39/200 patients). Hypertension (odds ratio [OR] 3.05, 95% confidence interval [CI] 1.07–8.68, P = 0.037), and moderate-to-severe white matter lesions (Fazekas 2–3, OR 7.61, 95% CI 3.06–18.95, P < 0.001) were related to the presence of CMBs. Conclusions: CMBs were found in 20% of patients with ischemic stroke, which was lower than those reported from Japanese studies but comparable to a Chinese study. CMBs were associated with hypertension and severity of the white matter lesions.

scholarly journals Actinomyces meyeriPopliteal Cyst Infection and Review of the Literature

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Bharath Raj Palraj ◽  
Ala S. Dababneh
Keyword(s):  
Fluid Collection ◽  
Left Knee ◽  
Joint Fluid ◽  
Popliteal Cyst ◽  
Degenerative Arthritis ◽  
Posterior Aspect ◽  
Medial Meniscectomy ◽  
Complex Fluid ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Study

A 66-year-old, Caucasian male presented with pain and swelling involving the left knee of one-week duration. Arthrocentesis was negative for evidence of septic arthritis. Magnetic resonance imaging (MRI) study of the left knee showed degenerative arthritis, partial tear of medial meniscus, and a complex fluid collection along the posteromedial aspect of the left knee suggestive of popliteal cyst. He underwent arthroscopy with partial medial meniscectomy. Intraoperative joint fluid was noted to be cloudy but cultures were negative. Arthroscopic procedure provided him with temporary relief but the pain and swelling in the posterior aspect of the left knee recurred in 6 weeks. Repeat MRI showed complex fluid collection in the posterolateral aspect of left knee. Ultrasound guided aspiration of the fluid collection revealed purulent material and cultures grewActinomyces meyeri. He was treated with 6 weeks of intravenous penicillin regimen followed by 18 months of oral penicillin.

scholarly journals Validating a Local Arterial Input Function Method for Improved Perfusion Quantification in Stroke

2011 ◽  
Vol 31 (11) ◽  
pp. 2189-2198 ◽  
Author(s):  
Lisa Willats ◽  
Soren Christensen ◽  
Henry K Ma ◽  
Geoffrey A Donnan ◽  
Alan Connelly ◽  
...  
Keyword(s):  
Time Course ◽  
Arterial Input Function ◽  
Input Function ◽  
Perfusion Magnetic Resonance Imaging ◽  
Data Sets ◽  
Bolus Tracking ◽  
Perfusion Quantification ◽  
Magnetic Resonance Imaging Mri ◽  
Arterial Input Functions ◽  
Contrast Bolus

In bolus-tracking perfusion magnetic resonance imaging (MRI), temporal dispersion of the contrast bolus due to stenosis or collateral supply presents a significant problem for accurate perfusion quantification in stroke. One means to reduce the associated perfusion errors is to deconvolve the bolus concentration time-course data with local Arterial Input Functions (AIFs) measured close to the capillary bed and downstream of the arterial abnormalities causing dispersion. Because the MRI voxel resolution precludes direct local AIF measurements, they must be extrapolated from the surrounding data. To date, there have been no published studies directly validating these local AIFs. We assess the effectiveness of local AIFs in reducing dispersion-induced perfusion error by measuring the residual dispersion remaining in the local AIF deconvolved perfusion maps. Two approaches to locating the local AIF voxels are assessed and compared with a global AIF deconvolution across 19 bolus-tracking data sets from patients with stroke. The local AIF methods reduced dispersion in the majority of data sets, suggesting more accurate perfusion quantification. Importantly, the validation inherently identifies potential areas for perfusion underestimation. This is valuable information for the identification of at-risk tissue and management of stroke patients.

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.

T1672 The Effects of Endogenous GLP-1 On Antro-Duodenal Contractility in the Fasted and Fed State: A Magnetic Resonance Imaging (MRI) Study

2009 ◽  
Vol 136 (5) ◽  
pp. A-555
Author(s):  
Elad Kaufman ◽  
Mark Fox ◽  
Michael Wyss ◽  
Zsofia Forras-Kaufman ◽  
Reto Treier ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Fed State ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Study

scholarly journals Perfusion Magnetic Resonance Imaging to Assess Brain Tumor Responses to New Therapies

1998 ◽  
Vol 5 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Michael H. Lev ◽  
Fred Hochberg
Keyword(s):  
Magnetic Resonance Imaging ◽  
Brain Tumor ◽  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Perfusion Mri ◽  
Perfusion Magnetic Resonance Imaging ◽  
Normal Brain ◽  
Resonance Imaging ◽  
New Therapies ◽  
Magnetic Resonance Imaging Mri

Background: Although magnetic resonance imaging (MRI) is effective in detecting the location of intracranial tumors, new imaging techniques have been studied that may enhance the specificity for the prediction of histologic grade of tumor and for the distinction between recurrence and tumor necrosis associated with cancer therapy. Methods: The authors review their experience and that of others on the use of perfusion magnetic resonance imaging to evaluate responses of brain tumors to new therapies. Results: Functional imaging techniques that can distinguish tumor from normal brain tissue using physiological parameters. These new approaches provide maps of tumor perfusion to monitor the effects of novel compounds that restrict tumor angiogenesis. Conclusions: Perfusion MRI not only may be as effective as radionuclide-based techniques in sensitivity and specificity in assessing brain tumor responses to new therapies, but also may offer higher resolution and convenient co-registration with conventional MRI, as well as time- and cost-effectiveness. Further study is needed to determine the role of perfusion MRI in assessing brain tumor responses to new therapies.

scholarly journals Analysis of diaphragm movement, during tidal breathing and during its activation while breath holding, using MRI synchronized with spirometry

2009 ◽  
pp. 383-392 ◽  
Author(s):  
P Kolář ◽  
J Neuwirth ◽  
J Šanda ◽  
V Suchánek ◽  
Z Svatá ◽  
...  
Keyword(s):  
Voluntary Movement ◽  
Sagittal Plane ◽  
Dynamic Mri ◽  
Breath Holding ◽  
Tidal Breathing ◽  
Average Amplitude ◽  
Test Conditions ◽  
Magnetic Resonance Imaging Mri ◽  
Costophrenic Angle ◽  
Voluntary Breath Holding

Using magnetic resonance imaging (MRI) in conjunction with synchronized spirometry we analyzed and compared diaphragm movement during tidal breathing and voluntary movement of the diaphragm while breath holding. Breathing cycles of 16 healthy subjects were examined using a dynamic sequence (77 slices in sagittal plane during 20 s, 1NSA, 240x256, TR4.48, TE2.24, FA90, TSE1, FOV 328). The amplitude of movement of the apex and dorsal costophrenic angle of the diaphragm were measured for two test conditions: tidal breathing and voluntary breath holding. The maximal inferior and superior positions of the diaphragm were subtracted from the corresponding positions during voluntary movements while breath holding. The average amplitude of inferio-superior movement of the diaphragm apex during tidal breathing was 27.3±10.2 mm (mean ± SD), and during voluntary movement while breath holding was 32.5±16.2 mm. Movement of the costophrenic angle was 39±17.6 mm during tidal breathing and 45.5±21.2 mm during voluntary movement while breath holding. The inferior position of the diaphragm was lower in 11 of 16 subjects (68.75 %) and identical in 2 of 16 (12.5 %) subjects during voluntary movement compared to the breath holding. Pearson’s correlation coefficient was used to demonstrate that movement of the costophrenic angle and apex of the diaphragm had a linear relationship in both examined situations (r=0.876). A correlation was found between the amplitude of diaphragm movement during tidal breathing and lung volume (r=0.876). The amplitude of movement of the diaphragm with or without breathing showed no correlation to each other (r=0.074). The movement during tidal breathing shows a correlation with the changes in lung volumes. Dynamic MRI demonstrated that individuals are capable of moving their diaphragm voluntarily, but the amplitude of movement differs from person to person. In this study, the movements of the diaphragm apex and the costophrenic angle were synchronous during voluntary movement of the diaphragm while breath holding. Although the sample is small, this study confirms that the function of the diaphragm is not only respiratory but also postural and can be voluntarily controlled.

scholarly journals Assessment of Albumin ECM Accumulation and Inflammation as Novel In Vivo Diagnostic Targets for Multi-Target MR Imaging

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 964
Author(s):  
Jana Möckel ◽  
Julia Brangsch ◽  
Carolin Reimann ◽  
Jan O. Kaufmann ◽  
Ingolf Sack ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Endothelial Damage ◽  
Plaque Burden ◽  
Signal Loss ◽  
Inductively Coupled ◽  
Before And After ◽  
Plasma Mass Spectrometry ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Study

Atherosclerosis is a progressive inflammatory vascular disease characterized by endothelial dysfunction and plaque burden. Extracellular matrix (ECM)-associated plasma proteins play an important role in disease development. Our magnetic resonance imaging (MRI) study investigates the feasibility of using two different molecular MRI probes for the simultaneous assessment of ECM-associated intraplaque albumin deposits caused by endothelial damage and progressive inflammation in atherosclerosis. Male apolipoprotein E-deficient (ApoE-/-)-mice were fed a high-fat diet (HFD) for 2 or 4 months. Another ApoE-/--group was treated with pravastatin and received a HFD for 4 months. T1- and T2*-weighted MRI was performed before and after albumin-specific MRI probe (gadofosveset) administration and a macrophage-specific contrast agent (ferumoxytol). Thereafter, laser ablation inductively coupled plasma mass spectrometry and histology were performed. With advancing atherosclerosis, albumin-based MRI signal enhancement and ferumoxytol-induced signal loss areas in T2*-weighted MRI increased. Significant correlations between contrast-to-noise-ratio (CNR) post-gadofosveset and albumin stain (R2 = 0.78, p < 0.05), and signal loss areas in T2*-weighted MRI with Perls’ Prussian blue stain (R2 = 0.83, p < 0.05) were observed. No interference of ferumoxytol with gadofosveset enhancement was detectable. Pravastatin led to decreased inflammation and intraplaque albumin. Multi-target MRI combining ferumoxytol and gadofosveset is a promising method to improve diagnosis and treatment monitoring in atherosclerosis.

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