scholarly journals Posterior cingulate gyri metabolic alterations in HIV-positive patients with and without memory deficits

2020 ◽  
Vol 53 (6) ◽  
pp. 359-365 ◽  
Author(s):  
Diogo G. Corrêa ◽  
Eelco van Duinkerken ◽  
Nicolle Zimmermann ◽  
Rochele P. Fonseca ◽  
Emerson L. Gasparetto
Keyword(s):  
Magnetic Resonance ◽  
Verbal Learning ◽  
Memory Deficits ◽  
Memory Deficit ◽  
Hiv Positive ◽  
Control Group ◽  
Resonance Spectroscopy ◽  
Posterior Cingulate ◽  
Cingulate Gyri

Abstract Objective: We aimed to evaluate whether human immunodeficiency virus (HIV)-positive patients with and without clinically significant memory deficits and healthy control participants differ on in vivo hydrogen-1 magnetic resonance spectroscopy (H-MRS) in the posterior cingulate gyri. Materials and Methods: In total, 21 HIV-positive patients with memory deficit (HIV+wMD) were compared with 15 HIV-positive patients without memory deficit (HIV+wOMD) and 22 sex-, age-, and education-matched control participants. Memory impairments were classified based on the participants’ performance on the Rey Auditory Verbal Learning Test. Short echo time (30 ms), single-voxel H-MRS was performed using a 1.5-T magnetic resonance scanner. Results: The HIV+wMD and HIV+wOMD groups had higher choline/creatine ratio in the posterior cingulate gyri than the control group. There were no significant metabolite ratio differences between the HIV+wMD and HIV+wOMD groups. Conclusion: HIV-positive patients with and without memory deficits had significantly higher choline/creatine ratios than controls in the posterior cingulate gyri, which may reflect cerebral inflammation, altered cell membrane metabolism, microgliosis, and/or astrocytosis.

Cardiac energetics alteration in chronic hypoxia rat model: a non invasive in vivo 31P magnetic resonance spectroscopy experimental study

2021 ◽  
Author(s):  
Xiaohan Yuan ◽  
Xiaomei Zhu ◽  
Yang Chen ◽  
Wangyan Liu ◽  
Wen Qian ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Right Ventricular ◽  
Myocardial Injury ◽  
Chronic Hypoxia ◽  
Volume Index ◽  
Control Group ◽  
Resonance Spectroscopy ◽  
Cardiac Energetics

Abstract Background: Energetics alteration plays a key role in the process of myocardial injury in chronic hypoxic diseases (CHD). 31P magnetic resonance spectroscopy (MRS) can investigate alterations in cardiac energetics in vivo. This study was aimed to characterize the potential value of 31P MRS in evaluating cardiac energetics alteration of chronic hypoxia rats (CHR).Methods: Twenty-four CHRs were induced by SU5416 combined with hypoxia, and six rats were raised as control group. 31P MRS was performed weekly and the ratio of concentrations of phosphocreatine (PCr) to adenosine triphosphate (ATP) (PCr/ATP) was obtained. The index of cardiac structure and systolic function parameters, including the right ventricular function (RVEF), right ventricular end-diastolic volume index (RVEDVi), right ventricular end-systolic volume index (RVESVi), the left ventricular function parameters were also measured.Results: The declension of resting cardiac PCr/ATP ratio in CHR was observed at the 1st week, compared to control group (2.90±0.35 vs. 3.31±0.45, p =0.045), while the RVEF，RVEDVi and RVESVi decreased at the 2nd week (p＜0.05). The PCr/ATP ratio displayed a significant correlation with RVEF(r = 0.605, p = 0.001)，RVEDVi and RVESVi (r = -0.661, r = -0.703; p＜0.001).Conclusions: 31P MRS can early detect the cardiac energetics alteration in CHR model before the onset of ventricular dysfunction. The decrease of PCr/ATP ratio likely revealed myocardial injury and cardiac dysfunction.

Regional metabolic changes in the hippocampus and posterior cingulate area detected with 3-Tesla magnetic resonance spectroscopy in patients with mild cognitive impairment and alzheimer disease

2009 ◽  
Vol 50 (3) ◽  
pp. 312-319 ◽  
Author(s):  
Zhiqun Wang ◽  
Cheng Zhao ◽  
Lei Yu ◽  
Weidong Zhou ◽  
Kuncheng Li
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Magnetic Resonance ◽  
Alzheimer Disease ◽  
Magnetic Resonance Spectroscopy ◽  
Normal Subjects ◽  
Control Group ◽  
Resonance Spectroscopy ◽  
Posterior Cingulate ◽  
Mini Mental Status Exam

Background: Magnetic resonance spectroscopy (MRS) plays an important role in early diagnosis of Alzheimer disease (AD). There are many reports on MRS studies among individuals with AD and mild cognitive impairment (MCI). However, very few studies have compared spectroscopic data of different limbic regions among AD and MCI subjects. Purpose: To compare metabolite changes of different regions in the brain of AD and MCI patients by using 3.0T short-echo-time MRS. Material and Methods: Metabolite ratios in the hippocampus and posterior cingulate area were compared in a group of patients with AD ( n=16), MCI ( n=16), and normal subjects as a control group ( n=16). Clinical neuropsychological tests were measured in all subjects. Results: In the hippocampus, there were significant differences in N-acetylaspartate (NAA)/creatine (Cr), myo-inositol (mI)/Cr, and mI/NAA ratios among the three groups. However, there were no significant differences in choline (Cho)/Cr ratio among the three groups. In the posterior cingulate area, there were no significant differences in the NAA/Cr, Cho/Cr, and mI/Cr ratios among the three groups. However, there were significant differences in mI/NAA ratio between patients with AD and the control group, and between the AD and MCI groups. In addition, there was significant correlation between mI/NAA ratio and Mini Mental Status Exam (MMSE) score in subjects with AD and MCI. Conclusion: The study reveals that the elevation of mI/NAA ratio in the hippocampus is more significant than that in the posterior cingulate area, which corresponds to the pathologic procession of AD. The ratios of mI/NAA in the hippocampus and in the posterior cingulate area together provide valuable discrimination among the three groups (AD, MCI, and controls). There is a significant correlation between mI/NAA ratio and cognitive decline.

Magnetic resonance imaging and 31P magnetic resonance spectroscopy for evaluating focal cerebral ischemia

1989 ◽  
Vol 70 (4) ◽  
pp. 612-618 ◽  
Author(s):  
Isabelle M. Germano ◽  
Lawrence H. Pitts ◽  
Isabelle Berry ◽  
Michael Moseley
Keyword(s):  
Cerebral Ischemia ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Focal Cerebral Ischemia ◽  
High Energy ◽  
Control Group ◽  
Resonance Spectroscopy ◽  
Mr Images ◽  
Ischemic Insult

✓ Recent advances in magnetic resonance (MR) imaging and MR spectroscopy (MRS) allow the noninvasive in vivo study of a variety of anatomical, physiological, and biochemical alterations that may occur in different cerebral pathologies. The authors have investigated the use of MR imaging and MRS to monitor the evolution of experimental focal cerebral ischemia in rats. Permanent focal cerebral ischemia was induced in 36 rats, and 12 normal rats were used as a control group. Changes in high-energy phosphate metabolites were followed in vivo using MRS during the 1st hour and at 3 and 6 hours after ischemic insult. Changes in in vivo MR images were evaluated at 1, 3, 6, 12, and 24 hours after ischemic insult. Significant decreases (p < 0.05) in phosphocreatine/inorganic phosphate ratios and intracellular pH values occurred immediately after the induction of ischemia. The presence of an infarcted area seen on MR images was a constant finding at 3 hours after ischemic insult, and was well defined and localized at 12 and 24 hours. The location of areas of infarction seen on MR images correlated well with areas identified histopathologically. The T1 and T2 MR relaxation times were significantly increased 3 hours after ischemic insult and remained prolonged for at least 24 hours. The results show that MR imaging is a sensitive method to measure cerebral infarction, and that MRS is a sensitive measure of changes that occur in the early phases of ischemia, perhaps when cellular changes may still be reversible. At 3 and 6 hours after the ischemic insult, however, 31P-MRS spectra may appear to be “normal” despite the presence of well-documented areas of infarction.

Cardiac energetics alteration in a chronic hypoxia rat model: A non-invasive in vivo 31P magnetic resonance spectroscopy study

2021 ◽  
pp. 1-11
Author(s):  
Xiaohan Yuan ◽  
Xiaomei Zhu ◽  
Yang Chen ◽  
Wangyan Liu ◽  
Wen Qian ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Right Ventricular ◽  
Myocardial Injury ◽  
Chronic Hypoxia ◽  
Volume Index ◽  
Control Group ◽  
Resonance Spectroscopy ◽  
Cardiac Energetics ◽  
31P Mrs

BACKGROUND: Energetics alteration plays a crucial role in the myocardial injury process in chronic hypoxia diseases (CHD). 31P magnetic resonance spectroscopy (MRS) can investigate alterations in cardiac energetics in vivo. OBJECTIVE: To characterize the potential value of 31P MRS in evaluating cardiac energetics alteration of chronic hypoxic rats (CHRs). METHODS: Twenty-four CHRs were induced by SU5416 combined with hypoxia and divided into four groups according to the modeling time of one, two, three and five weeks, respectively. Control group also contains six rats. 31P MRS was performed weekly and the ratio of concentrations of phosphocreatine (PCr) to adenosine triphosphate (ATP) (PCr/ATP) was obtained. In addition, the cardiac structure index and systolic function parameters, including the right ventricular ejection fraction (RVEF), right ventricular end-diastolic volume index (RVEDVi), right ventricular end-systolic volume index (RVESVi), and the left ventricular function parameters, were measured. RESULTS: Decreased resting cardiac PCr/ATP ratio in CHRs was observed at the first week, compared to the control group (2.90±0.35 vs. 3.31±0.45, p = 0.045), while the RVEF, RVEDVi, and RVESVi decreased at the second week (p <  0.05). The PCr/ATP ratio displayed a significant correlation with RVEF (r = 0.605, p = 0.001), RVEDVi, and RVESVi (r = –0.661, r = –0.703; p <  0.001). CONCLUSIONS: 31P MRS can easily detect the cardiac energetics alteration in a CHR model before the onset of ventricular dysfunction. The decreased PCr/ATP ratio likely reveales myocardial injury and cardiac dysfunction.

Spectroscopic imaging of human disease

1996 ◽  
Vol 54 ◽  
pp. 884-885
Author(s):  
D.J. Meyerhoff
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Human Disease ◽  
Morphological Changes ◽  
Magnetic Field Gradient ◽  
Spectroscopic Imaging ◽  
Resonance Spectroscopy ◽  
Tissue Water

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

Rapid Catalyst Capture Enables Metal-Free Parahydrogen-Based Hyperpolarized Contrast Agents

2018 ◽  
Author(s):  
Danila Barskiy ◽  
Lucia Ke ◽  
Xingyang Li ◽  
Vincent Stevenson ◽  
Nevin Widarman ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Contrast Agents ◽  
Inductively Coupled Plasma ◽  
Organometallic Compounds ◽  
Atomic Emission ◽  
Platinum Group Metals ◽  
Resonance Spectroscopy ◽  
Plasma Atomic Emission ◽  
Inductively Coupled

<p>Hyperpolarization techniques based on the use of parahydrogen provide orders of magnitude signal enhancement for magnetic resonance spectroscopy and imaging. The main drawback limiting widespread applicability of parahydrogen-based techniques in biomedicine is the presence of organometallic compounds (the polarization transfer catalysts) in solution with hyperpolarized contrast agents. These catalysts are typically complexes of platinum-group metals and their administration in vivo should be avoided.</p> <p><br></p><p>Herein, we show how extraction of a hyperpolarized compound from an organic phase to an aqueous phase combined with a rapid (less than 10 seconds) Ir-based catalyst capture by metal scavenging agents can produce pure parahydrogen-based hyperpolarized contrast agents as demonstrated by high-resolution nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The presented methodology enables fast and efficient means of producing pure hyperpolarized aqueous solutions for biomedical and other uses.</p>

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