OBJECTIVESTo evaluate the diagnostic value of arterial spin labeling (ASL) technology in newborns with hypoxic ischemic encephalopathy (HIE).

METHODSeven full-term newborn infants without any history of asphyxia and other nervous system diseases were selected as the control and 33 full-term newborn infants were assigned into HIE group. The patients in HIE group were further divided into three subgroups (19 cases of mild, 6 cases of moderate and 8 cases of severe HIE) based on their clinical diagnosis. The control group and HIE group were examined with GE Signa EXCITE HD 3.0T superconducting MRI scanner with a head phase array coil. Both groups were scanned with conventional axial MRI (T1FLAIR, T2WI and T2FLAIR), 1HMRS (PRESS sequence) and ASL (FAIR). Original images of 1HMRS and ASL were processed by Functool software of ADW 4.3 workstation. ASL perfusion images were observed and the signal intensity values of the region of interest (bilateral gray, white matter and basal ganglia) of the two groups were quantitatively measured, and mean value were calculated and compared between groups. Statistical analysis was performed with SPSS 13.0 software, and statistically significant difference was set at P < 0.05.

RESULTThe perfusion images of two groups were obtained perfectly. The signal intensity values of bilateral gray, white matter and basal ganglia of control group were 125.34 ± 11.76, 73.42 ± 11.67 and 173.65 ± 15.49, respectively and there was a statistically significant difference between the different areas. The signal intensity values of bilateral gray, white matter and basal ganglia of HIE group were 153.47 ± 11.72, 71.35 ± 10.37 and 217.13 ± 12.51, respectively. There was a statistically significant difference (P < 0.05) in the average signal intensity value of gray matter and basal ganglia, but there were no statistically significant difference (P > 0.05) in white matter between the two groups.

CONCLUSIONASL Perfusion technique can assess HIE comprehensively and accurately. Furthermore, it can evaluate the brain damage of hypoxic ischemia. The results provide a strong basis for clinical treatment.

Case-Control Studies ; Electron Spin Resonance Spectroscopy ; Female ; Humans ; Hypoxia-Ischemia, Brain ; diagnosis ; Infant, Newborn ; Male ; Spin Labels

Electron Spin Resonance Spectroscopy ; Glycerol ; chemistry ; Mesylates ; chemistry ; Muramidase ; chemistry ; Protein Structure, Tertiary ; Proteins ; chemistry ; Spin Labels ; Temperature ; Viscosity

This article describes the preparation of the N-tert-butyl-alpha-phenylnitrone (PBN) liposomes and their related characteristics. The PBN liposomes were prepared by film dispersion-supersonic method and the formula of liposomes was optimized by orthogonal uniform design. RP-HPLC was used to qualify the amount of PBN that entered into the hepatoma cells. Necrosis rate was also investigated by fluorescence activated cell sorter (FACS) after PBN liposomes transfection. Result showed that the mean particle size, entrapment efficiency, and polydispersity of the resulting PBN-liposome were 137.5 nm, 71.52% and 0.286, respectively. PBN liposomes can enter into the tumor cell stably and they have higher affinity to hepatoma cell compared with free PBN resulting in a higher necrosis rate after transfection. These results provide a potential method for early diagnosis and treatment of cancer using specific spin trapping probe targeting tumor cells.
Carcinoma, Hepatocellular ; pathology ; Cyclic N-Oxides ; chemistry ; Electron Spin Resonance Spectroscopy ; Humans ; Nanoparticles ; chemistry ; Spin Labels ; Spin Trapping ; methods ; Tumor Cells, Cultured

Multiple sclerosis (MS) is a common inflammatory demyelinating disorder of central nervous system, and the disease burder could be well evaluated by conventional magnetic resonance imaging (MRI), including T2-weighted, fluid-attenuatd inversion recovery, and postcontrast T1-weighted sequences. We investigated the perfusion state of MS plaques using brain perfusion imaging in a 12-year-old boy with MS.
Child ; Humans ; Magnetic Resonance Imaging ; Male ; Multiple Sclerosis ; pathology ; Spin Labels

Objective To acquire cerebral blood flow (CBF) in patients with severe intracranial atherosclerotic stenosis with enhanced pseudo-continuous arterial spin labeling (e-pCASL) and compare it with the findings of dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC PWI) and pseudo-continuous arterial spin labeling (pCASL). Methods A total of 39 consecutive patients with severe intracranial atherosclerotic stenosis were enrolled in this study. All these patients underwent e-pCASL, pCASL, and DSC PWI. Blood supply territory of the stenosed artery was outlined as region of interest (ROI) and a mirror ROI was applied. Ratios of CBF were calculated as value of ROI/value of mirror ROI. SNK variance analysis was conducted to compare the CBF values of three persufion methods. Factorial analysis of variance and Pearson were employed to analysis the difference and the correlation of e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI relative cerebral blood flow(rCBF) ratio. Results The e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI rCBF ratio were not significantly different (P=0.476). TTP showed the CBF ratios were not significantly different between the healthy side and diseased side in patients with severe intracranial atherosclerotic stenosis. ATT showed the correlations of pCASL CBF ratio and DSC PWI rCBF ratio were not affected by ATT. Conclusions e-pCASL with multiple-post labeling delay time and pCASL have good consistency with DSC PWI in the quantitative measurement of hypoperfusion pattern. As an accurate, simple, non-invasive, and repeatable technique, e-pCASL has good correlation with DSC PWI in the quantitative measurement of hypoperfusion pattern that is not affected by ATT.
Cerebrovascular Circulation ; Constriction, Pathologic ; Humans ; Intracranial Arteriosclerosis ; diagnostic imaging ; Perfusion Imaging ; Spin Labels

Arterial spin labeling is a noninvasive,quantitative method for perfusion imaging,which does not need any contrast media.This technique has been used in the renal perfusion analysis.In this article,we briefly introduced this technique and summarized its application in healthy volunteers,acute kidney injury,chronic kidney diseases,renovascular diseases,renal tumors,and renal transplantation.
Humans ; Kidney/diagnostic imaging* ; Magnetic Resonance Imaging ; Perfusion ; Perfusion Imaging ; Renal Insufficiency, Chronic ; Spin Labels

Perfusion is a fundamental biological function that refers to the delivery of oxygen and nutrients to tissue by means of blood flow. Perfusion MRI is sensitive to microvasculature and has been applied in a wide variety of clinical applications, including the classification of tumors, identification of stroke regions, and characterization of other diseases. Perfusion MRI techniques are classified with or without using an exogenous contrast agent. Bolus methods, with injections of a contrast agent, provide better sensitivity with higher spatial resolution, and are therefore more widely used in clinical applications. However, arterial spin-labeling methods provide a unique opportunity to measure cerebral blood flow without requiring an exogenous contrast agent and have better accuracy for quantification. Importantly, MRI-based perfusion measurements are minimally invasive overall, and do not use any radiation and radioisotopes. In this review, we describe the principles and techniques of perfusion MRI. This review summarizes comprehensive updated knowledge on the physical principles and techniques of perfusion MRI.
Arteries/chemistry ; Brain Neoplasms/radiography ; Contrast Media/diagnostic use ; Humans ; Magnetic Resonance Imaging/standards/*trends ; Spin Labels ; Stroke/radiography

Arterial spin labeling (ASL) technique is a kind of perfusion functional magnetic resonance imaging method that is based on endogenous contrast, and it can measure cerebral blood flow (CBF) noninvasively. The ASL technique has advantages of noninvasiveness, simplicity and relatively lower costs so that it is more suitable for longitudinal studies compared with previous perfusion methods, such as positron emission tomography (PET), single photon emission computed tomography (SPECT), CT and the contrast agent based magnetic resonance perfusion imaging. This paper mainly discusses the current clinical applications of ASL in brain diseases as cerebrovascular diseases, brain tumors, Alzheimer's disease and epilepsy, etc.
Animals ; Brain Diseases ; diagnosis ; Brain Neoplasms ; diagnosis ; Cerebrovascular Circulation ; Cerebrovascular Disorders ; diagnosis ; Humans ; Magnetic Resonance Imaging ; methods ; Perfusion ; Spin Labels

PURPOSE: Demonstrate unequivocally the generation of nitric oxide in experimental autoimmune uveoretinitis by electron spin resonance spectroscopy (ESR) using ferrous iron complex of N-methyl-D-glucamine dithiocarbamate, (MGD)2-Fe2+, as a spin trap. METHODS: Experimental autoimmune uveitis was induced in Lewis rats, and at the peak of the intraocular inflammation, the animals received intravitreous injections of the spin trap. The retina and choroid dissected from the enucleated globes were subjected to ESR. Similarly, the retina and choroid obtained at the peak of experimental autoimmune uveo-retinitis (EAU) were placed in a vial containing luminal, and chemiluminescence was counted on a Packard liquid scintillation analyzer. RESULTS: The ESR three-line spectrum (g=2.04; a(N)=12.5 G) obtained was characteristic of the adduct [(MGD)2-Fe2+-NO]. The majority of this signal was eliminated by the inducible nitric oxide synthase (iNOS) specific inhibitor aminoguanidine injected inflamed retina was detected when compared with that of the non inflamed controls. The chemiluminescent activity was further increased two-fold by the addition of bicarbonate to the inflamed retina; the phenomenon is attributable only to the presence of a high steady-state concentration of peroxynitrite. CONCLUSIONS: The study shows an unequivocal presence of nitric oxide in EAU retina and choroid and the generation of peroxynitrite. High levels of these reactive nitrogen species generated in the inflamed retina and choroids are certain to cause irreversible tissue damage, especially at the susceptible sites such as photoreceptors.
Uveitis/immunology/*metabolism ; Thiocarbamates ; Spin Trapping ; Spin Labels ; Sorbitol/analogs & derivatives ; Retina/metabolism ; Reactive Nitrogen Species/*metabolism ; Rats, Inbred Lew ; Rats ; Peptide Fragments/immunology ; Humans ; Electron Spin Resonance Spectroscopy ; Choroid/metabolism ; Autoimmune Diseases/immunology/*metabolism ; Arrestin/immunology ; Animals

OBJECTIVETo evaluate the clinical value of three-dimensional pseudo-continuous arterial spin labeling (3D pCASL) perfusion magnetic resonance imaging (MRI) and dynamic susceptibility contrast (DSC) enhanced perfusion MRI in the diagnosis of transient ischemic attack (TIA).

METHODSThirty-nine consecutive patients with suspected TIA underwent multi-modal MRI scans including DSC, magnetic resonance angiography (MRA), diffusion-weighted imaging (DWI) and 3D pCASL (post-labeling delay, PLD=1.5 s and 2.5 s) within 24 h of symptom onset. Cerebral blood flow (CBF) from ASL and the time to the maximum of tissue residual function (Tmax) map from DSC were calculated using AW workstation. DWI and MRA were applied to detect acute cerebral infarction and intracranial artery stenosis. Two neuroradilogists who were blinded to the patients' clinical data assessed the presence of perfusion deficit, ischemic lesion and the lesion sites both from 1.5 s, 2.5 s PLD ASL-CBF and DSC-Tmax independently, and then graded them. The differences in the ranking grades between 1.5 s, 2.5 s PLD ASL and DSC were analyzed, and the frequency of lesion detection was compared between ASL-CBF, Tmax and MRA combining DWI method.

RESULTSNo significant differences was found in hypoperfusion grades detected by 3D pCASL (including PLD1.5 s and 2.5 s) CBF and Tmax maps, while significant differences were detected between 1.5 s PLD ASL-CBF and MRA combining DWI method; ASL with PLD 1.5 s CBF detected ischemic lesions and lesion site significantly more frequently than MRA combining DWI method.

CONCLUSIONs Three dimensional pCASL is a non-invasive perfusion method free of radiation exposure, and short PLD ASL is more sensitive than long PLD ASL for detecting ischemic lesions and lesion sites.

Arteries ; physiopathology ; Brain ; physiopathology ; Brain Infarction ; diagnosis ; Brain Ischemia ; diagnosis ; Cerebrovascular Circulation ; Diffusion Magnetic Resonance Imaging ; Humans ; Magnetic Resonance Angiography ; Perfusion ; Perfusion Imaging ; Spin Labels