scholarly journals Interobserver Reproducibility of Signal Intensity Ratio on Magnetic Resonance Angiography for Hemodynamic Impact of Intracranial Atherosclerosis

2013 ◽  
Vol 22 (8) ◽  
pp. e615-e619 ◽  
Author(s):  
Xinyi Leng ◽  
Hing Lung Ip ◽  
Yannie Soo ◽  
Thomas Leung ◽  
Liping Liu ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Signal Intensity Ratio ◽  
Intracranial Atherosclerosis ◽  
Interobserver Reproducibility

scholarly journals Quantitative Analysis of Apoptotic Cell Death Using Proton Nuclear Magnetic Resonance Spectroscopy

Blood ◽  
1997 ◽  
Vol 89 (10) ◽  
pp. 3778-3786 ◽  
Author(s):  
Francis G. Blankenberg ◽  
Peter D. Katsikis ◽  
Richard W. Storrs ◽  
Christian Beaulieu ◽  
Daniel Spielman ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Death ◽  
Magnetic Resonance ◽  
1H Nmr ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Apoptotic Cell ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Signal Intensity Ratio

Abstract Quantification of apoptotic cell death in vivo has become an important area of investigation in patients with acute lymphoblastic leukemia (ALL). We have devised a noninvasive analytical method to estimate the percentage of apoptotic lymphoblasts in doxorubicin-treated Jurkat T-cell ALL cultures, using proton nuclear magnetic resonance spectroscopy (1H NMR). We have found that the ratio of the methylene (CH2 ) resonance (at 1.3 ppm) to the methyl (CH3 ) resonance (at 0.9 ppm) signal intensity, as observed by 1H NMR, is directly proportional to the percentage of apoptotic lymphoblasts in vitro. The correlation between the CH2/CH3 signal intensity ratio and the percentage of apoptotic lymphoblasts was optimal 24 to 28 hours after doxorubicin treatment (r2 = .947, N = 27 samples). There was also a direct temporal relationship between an increase in the CH2/CH3 signal intensity ratio and the onset of apoptosis as detected by nuclear morphologic analysis, fluorescein-annexin V flow cytometry, and DNA gel electrophoresis. Thin-layer chromatography confirmed that a dynamic and/or compositional change of the plasma membrane, rather than increases in lipase activity or fatty acid production, appears to account for the increase in the CH2/CH3 signal intensity ratio during apoptosis. 1H NMR may have clinical utility for the early noninvasive assessment of chemotherapeutic efficacy in patients with ALL.

scholarly journals Ultrasonography compared to magnetic resonance imaging in thyroid-associated Graves' ophthalmopathy

2011 ◽  
Vol 55 (3) ◽  
pp. 184-188 ◽  
Author(s):  
Ana R. Vlainich ◽  
João H. Romaldini ◽  
Ana B. Pedro ◽  
Chady S. Farah ◽  
Cicero A. Sinisgalli Jr.
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Inverse Correlation ◽  
Poor Correlation ◽  
Clinical Activity ◽  
Signal Intensity Ratio ◽  
Resonance Imaging ◽  
Graves Ophthalmopathy

OBJECTIVE: To compare ultrasonography (US) to magnetic resonance imaging (MRI) and the clinical activity score (CAS) in Graves' ophthalmopathy. SUBJECTS AND METHODS: Nineteen patients underwent extraocular muscle thickness measurements by US and MRI, reflectivity by US and signal-intensity ratio by MRI. There were also twelve US control subjects. RESULTS: US median thicknesses were greater than in controls. Correlation was found between US and MRI in the median thickness of the left eye rectus medial muscle as well as between signal-intensity ratio (SIR) and thickness by US. An inverse correlation was found between reflectivity and SIR in the inferior and lateral rectus. On associating the tests for detecting activity the best results were obtained with CAS plus MRI (sensitivity 75%), and US and MRI (positive predictive value 77% and specificity 80%). CONCLUSION: CAS and US results showed poor correlation with MRI results suggesting that they cannot replace each other but when combined these methods can improve the evaluation of thyroid-associated ophthalmopathy.

Lipid Core Burden Index Assessed by Near-Infrared Spectroscopy of Symptomatic Carotid Plaques: Association with Magnetic Resonance T1-Weighted Imaging

2021 ◽  
pp. 1-8
Author(s):  
Ichiro Nakagawa ◽  
Masashi Kotsugi ◽  
HunSoo Park ◽  
Shohei Yokoyama ◽  
Takanori Furuta ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Carotid Artery ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Near Infrared ◽  
Signal Intensity Ratio ◽  
Plaque Imaging ◽  
Lipid Core ◽  
Symptomatic Carotid

<b><i>Introduction:</i></b> Vulnerable plaques are a strong predictor of cerebrovascular ischemic events, and high lipid core plaques (LCPs) are associated with an increased risk of embolic infarcts during carotid artery stenting (CAS). Recent developments in magnetic resonance (MR) plaque imaging have enabled noninvasive assessment of carotid plaque vulnerability, and the lipid component and intraplaque hemorrhage (IPH) are visible as high signal intensity areas on T1-weighted MR images. Recently, catheter-based near-infrared spectroscopy (NIRS) has been shown to accurately distinguish LCPs without IPH. This study aimed to determine whether the results of assessment of high LCPs by catheter-based NIRS correlate with the results of MR plaque imaging. <b><i>Methods:</i></b> We recruited 82 consecutive symptomatic carotid artery stenosis patients who were treated with CAS under NIRS and MR plaque assessment. Maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA), defined as max-LCBI<sub>MLA</sub>, and max-LCBI for any 4-mm segment in a target lesion, defined as max-LCBI<sub>AREA</sub>, were assessed by NIRS. Correlations were investigated between max-LCBI and MR T1-weighted plaque signal intensity ratio (T1W-SIR) and MR time-of-flight signal intensity ratio (TOF-SIR) in the same regions as assessed by NIRS. <b><i>Results:</i></b> Both T1W-SIR<sub>MLA</sub> and T1W-SIR<sub>AREA</sub> were significantly lower in the high LCP group (max-LCBI &#x3e;504, <i>p</i> &#x3c; 0.001 for both), while TOF-SIR<sub>MLA</sub> and TOF-SIR<sub>AREA</sub> were significantly higher in the high LCP group (<i>p</i> &#x3c; 0.001 and <i>p</i> = 0.004, respectively). A significant linear correlation was present between max-LCBI<sub>MLA</sub> and both TIW-SIR<sub>MLA</sub> and TOF-SIR<sub>MLA</sub> (<i>r</i> = −0.610 and 0.452, respectively, <i>p</i> &#x3c; 0.0001 for both). Furthermore, logistic regression analysis revealed that T1W-SIR<sub>MLA</sub> and TOF-SIR<sub>MLA</sub> were significantly associated with a high LCP assessed by NIRS (OR, 44.19 and 0.43; 95% CI: 6.55–298.19 and 0.19–0.96; <i>p</i> &#x3c; 0.001 and = 0.039, respectively). <b><i>Conclusions:</i></b> A high LCP assessed by NIRS correlates with the signal intensity ratio of MR imaging in symptomatic patients with unstable carotid plaques.

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