The relationship between myocardial and hepatic T2 and T2* at 1.5T and 3T MRI in normal and iron-overloaded patients

Background Cardiac and liver iron assessment using magnetic resonance imaging (MRI) is non-invasive and used as a preclinical “endpoint” in asymptomatic patients and for serial iron measurements in iron-overloaded patients. Purpose To compare iron measurements between hepatic and myocardial T2* and T2 at 1.5T and 3T MRI in normal and iron-overloaded patients. Material and Methods The T2 and T2* values from the regions of interest (ROIs) at mid-left ventricle and mid-hepatic slices were evaluated by 1.5T and 3T MRI scans for healthy and iron-overloaded patients. Results For iron-overloaded patients, the myocardial T2 (1.5T) and myocardial T2 (3T) values were 60.3 ms (range = 56.2–64.8 ms) and 55 ms (range = 51.6–60.1 ms) (ρ = 0.3679) while the myocardial T2* (3T) 20.5 ms (range = 18.4–25.9 ms) was shorter than the myocardial T2* (1.5T) 35.9 ms (range = 31.4–39.5 ms) (ρ = 0.6454). The hepatic T2 at 1.5T and 3T were 19.1 ms (range = 14.8–27.9 ms) and 15.5 ms (14.6–20.4 ms) (ρ = 0.9444) and the hepatic T2* at 1.5T and 3T were 2.7 ms (range = 1.8–5.6 ms) and 1.8 ms (range = 1.1–2.9 ms) (ρ = 0.9826). The line of best fit exhibiting the linearity of the hepatic T2* (1.5T) and hepatic T2* (3T) had a slope of 2 and an intercept of –0.387 ms (R = 0.984). Conclusion Our study found myocardial T2 (1.5T) nearly equal to T2 (3T) with myocardial T2* (3T) 1.75 shorter than myocardial T2* (1.5T). The relationship of hepatic T2* (1.5T) and hepatic T2* (3T) was linear with T2* (1.5T) approximately double to T2* (3T) in iron-overloaded patients. This linear relationship between hepatic T2* (1.5T) and hepatic T2 (3T) could be an alternative method for estimating liver iron concentration (LIC) from 3T.

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Localisation in PET Images: Direct Fitting of the Intercommissural (AC—PC) Line

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1989.97 ◽

1989 ◽

Vol 9 (5) ◽

pp. 690-695 ◽

Cited By ~ 217

Author(s):

K. J. Friston ◽

R. E. Passingham ◽

J. G. Nutt ◽

J. D. Heather ◽

G. V. Sawle ◽

...

Keyword(s):

Angular Displacement ◽

Positron Emission ◽

Total Brain ◽

Mri Scans ◽

Line Passing ◽

Occipital Pole ◽

Magnetic Resonance Imaging Mri ◽

Relationship Of ◽

The Relationship ◽

The Brain

A technique is described for estimating the position of the intercommisural line (AC–PC line) directly from landmarks on positron emission tomographic (PET) images, namely the ventral aspects of the anterior and posterior corpus callosum, the thalamus, and occipital pole. The relationship of this estimate to the true AC–PC line, fitted through the centres of the anterior and posterior commissures, showed minimal vertical and angular displacement when measured on magnetic resonance imaging (MRI) scans. Using regression analysis, the ease and reliability of fitting to these points was found to be high. This directly derived AC–PC line estimate was validated in terms of the assumptions used in the method of Fox et al. The ratio of distance between the AC–PC line and a line passing through the base of the inion (GI line) to total brain height was 0.21, as predicted. The technique has been further validated by localizing focal activation of the sensorimotor cortex. The technique is discussed in terms of absolute limits to localization of structures in the brain using noninvasive tomographic techniques in general and PET in particular.

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A longitudinal study examining the independence of apathy and depression after stroke: the Sydney Stroke Study

International Psychogeriatrics ◽

10.1017/s1041610209991116 ◽

2010 ◽

Vol 23 (2) ◽

pp. 264-273 ◽

Cited By ~ 45

Author(s):

Adrienne Withall ◽

Henry Brodaty ◽

Annette Altendorf ◽

Perminder S. Sachdev

Keyword(s):

Vascular Pathology ◽

Common Risk Factor ◽

Stroke Study ◽

Mri Scans ◽

Neuropsychological Assessments ◽

Dsm Iv ◽

Magnetic Resonance Imaging Mri ◽

Relationship Of ◽

The Relationship

ABSTRACTBackground: There is growing recognition that apathy is not only a symptom of depression but may be an independent syndrome. This is the first study to investigate the relationship of apathy and depression longitudinally following stroke and to examine the association with dementia.Method: 106 consecutive eligible participants following stroke received extensive medical, psychiatric and neuropsychological assessments at three to six months (index assessment) and 15 months (follow-up assessment) after their stroke. A subset of participants received magnetic resonance imaging (MRI) scans at index assessment. Ratings were made for DSM-IV major or minor depression and for apathy using the Apathy Evaluation Scale (AES).Results: While there was no significant overlap between apathy and depression at index assessment (OR = 1.79, 95% CI 0.48, 6.66), the overlap was significant a year later (OR = 7.75, 95% CI 2.60, 23.13). Dementia at index assessment was a common risk factor for both apathy and depression at follow-up (OR = 12.45, 95% CI 2.98, 52.02 and OR = 10.35, 95% CI 2.84, 37.72, respectively).Conclusions: Apathy and depression after stroke have a common predictor and overlap longitudinally. The overlap might be due to cumulative vascular pathology and because of the relationship of each of these syndromes to dementia, which was an important, possibly causal, predictor for both.

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MRI Prospective Survey on Cardiac and Hepatic Iron in Thalassemia Intermedia Patients Treated with Desferrioxamine, Deferiprone and Deferasirox

Blood ◽

10.1182/blood.v124.21.4041.4041 ◽

2014 ◽

Vol 124 (21) ◽

pp. 4041-4041

Author(s):

Antonella Meloni ◽

Aurelio Maggio ◽

Anna Pietrapertosa ◽

Pier Paolo Bitti ◽

Sabrina Armari ◽

...

Keyword(s):

Iron Overload ◽

Iron Concentration ◽

Iron Chelation ◽

Hepatic Iron ◽

Thalassemia Intermedia ◽

Liver Iron ◽

Cardiac Iron ◽

Number Of Patients ◽

Mri Scans ◽

Magnetic Resonance Imaging Mri

Abstract Background. Few studies have evaluated the efficacy of iron chelation therapy in thalassemia intermedia (TI) patients. Our study aimed to prospectively assess by quantitative Magnetic Resonance imaging (MRI) the efficacy of the three available chelators in monotherapy in transfusion dependent (TD) TI patients. Methods. Among the 325 TI patients enrolled in the MIOT (Myocardial Iron Overload in Thalassemia) network, we selected 103 TI patients TD with an MRI follow-up (FU) study at 18±3 months who had been received one chelator alone between the two MRI scans. Iron overload was assessed by the T2* multiecho technique. Hepatic T2* values were converted into liver iron concentration (LIC) values. Results. Three groups of patients were identified: 27 patients (13 females, mean age 40.12±10.31 years) treated with desferioxamine (DFO – mean dosage 37.52±8.69 mg/kg/die), 23 patients (14 females, mean age 34.73±10.67 years) treated with deferiprone (DFP– dosage 71.70±14.46mg/kg/die) and 14 patients (9 females, mean age 36.63±10.92 years) treated with deferasirox (DFX – mean dosage 27.75±5.04 mg/kg/die). Excellent/good levels of compliance were similar in the DFO (92.6%), DFP (100%) and DFX (100%) groups (P=0.345). The mean starting age of regular transfusion was 14.73±15.89 years. At baseline in DFO group two patients (7.4%) showed a global heart T2*<20 ms and one of them showed no cardiac iron at the FU. At baseline in DFP group two patients (8.7%) showed a global heart T2*<20 ms and one of them showed no cardiac iron at the FU. All the 5 patients (35.7%) under DFX therapy with pathological global heart T2* at the baseline remained at the same status at the FU. The percentage of patients who maintained a normal global heart T2* value was comparable for DFO (100%), DFP (100%) and DFX (88.9%) groups (P=0.164). Among the 46 patients with hepatic iron at baseline (MRI LIC ≥3 mg/g/dw), the reduction in the MRI LIC values was significant only in the DFO group (DFO: -3.39±6.38 mg/g/dw P=0.041; DFP: -2.25±6.01 mg/g/dw P=0.136 and DFX: -0.36±5.56 mg/g/dw P=0.875). The decrease in MRI LIC values was comparable among the groups (P=0.336). The number of patients with a MRI LIC<3 mg/g/dw went up from 10 (37%) to 11 (40.7%) in the DFO group, from 6 (26.1%) to 8 (34.8%) in the DFP group and from 2 (14.3%) to 8 (57.1%) in the DFX group. The percentage of patients who maintained a normal MRI LIC value was comparable for DFO (90%) vs DFP (50%) and DFX (100%) groups (P=0.191). Conclusion: Prospectively in transfusion-dependent TI patients at the dosages used in the clinical practice, DFO and DFP showed 100% efficacy in maintaining a normal global heart T2* value while DFX had 100% efficacy in maintaining a normal LIC value. Further prospective studies involving more patients with iron at the baseline are needed to establish which is the most effective drug in reducing iron levels. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Pepe: Chiesi: Speakers Bureau; ApoPharma Inc.: Speakers Bureau; Novartis: Speakers Bureau.

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Hepatocellular Carcinoma in β-Thalassemia Patients: Review of the Literature with Molecular Insight into Liver Carcinogenesis

International Journal of Molecular Sciences ◽

10.3390/ijms19124070 ◽

2018 ◽

Vol 19 (12) ◽

pp. 4070 ◽

Cited By ~ 4

Author(s):

Antoine Finianos ◽

Charbel Matar ◽

Ali Taher

Keyword(s):

Hepatocellular Carcinoma ◽

Iron Overload ◽

Treatment Success ◽

Iron Concentration ◽

Iron Chelation ◽

Multicenter Studies ◽

Major Life ◽

Liver Iron ◽

Magnetic Resonance Imaging Mri ◽

Personalized Approach

With the continuing progress in managing patients with thalassemia, especially in the setting of iron overload and iron chelation, the life span of these patients is increasing, while concomitantly increasing incidences of many diseases that were less likely to show when survival was rather limited. Hepatocellular carcinoma (HCC) is a major life-threatening cancer that is becoming more frequently identified in this population of patients. The two established risk factors for the development of HCC in thalassemia include iron overload and viral hepatitis with or without cirrhosis. Increased iron burden is becoming a major HCC risk factor in this patient population, especially in those in the older age group. As such, screening thalassemia patients using liver iron concentration (LIC) measurement by means of magnetic resonance imaging (MRI) and liver ultrasound is strongly recommended for the early detection of iron overload and for implementation of early iron chelation in an attempt to prevent organ-damaging iron overload and possibly HCC. There remain lacking data on HCC treatment outcomes in patients who have thalassemia. However, a personalized approach tailored to each patient’s comorbidities is essential to treatment success. Multicenter studies investigating the long-term outcomes of currently available therapeutic options in the thalassemia realm, in addition to novel HCC therapeutic targets, are needed to further improve the prognosis of these patients.

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Spontaneous Eye Blink Rate during the Working Memory Delay Period Predicts Task Performance

10.1101/2021.03.15.435433 ◽

2021 ◽

Author(s):

Jefferson Ortega ◽

Chelsea Reichert Plaska ◽

Bernard A Gomes ◽

Timothy M Ellmore

Keyword(s):

Working Memory ◽

Task Performance ◽

Memory Task ◽

Delay Period ◽

Blink Rate ◽

Indirect Measure ◽

Eye Blink ◽

Non Invasive ◽

Relationship Of ◽

The Relationship

Spontaneous eye blink rate (sEBR) has been found to be a non-invasive indirect measure of striatal dopamine activity. Dopamine (DA) neurons project to the prefrontal cortex (PFC) through the mesocortical dopamine pathway and their activity is implicated in a range of cognitive functions, including attention and working memory (WM). The goal of the present study was to understand how fluctuations in sEBR during different phases of a working memory task relate to task performance. Across two experiments, with recordings of sEBR inside and outside of a magnetic resonance imaging bore, we observed sEBR to be positively correlated with WM performance during the WM delay period. Additionally we investigated the non-linear relationship between sEBR and WM performance, and modeled a proposed Inverted-U-shape relationship between DA and WM performance. We also investigated blink duration, which is proposed to be related to sustained attention, and found blink duration to be significantly shorter during the encoding and probe periods of the task. Taken together, these results provide support towards sEBR as an important correlate of working memory task performance. The relationship of sEBR to DA activity and the influence of DA on the PFC during WM maintenance is discussed.

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The relationship of invasive and non-invasive respiratory therapy to the risk of developing the Retinopathy of Prematurity (ROP)

BMC Proceedings ◽

10.1186/1753-6561-9-s7-a2 ◽

2015 ◽

Vol 9 (S7) ◽

Author(s):

Bolshova Alina Sergeevna ◽

Krushelnickii Anatoliy Aleksandrovich ◽

Stepanova Ekaterina Vladimirovna ◽

Degterev Dmitrii Nickolaevich

Keyword(s):

Retinopathy Of Prematurity ◽

Respiratory Therapy ◽

Non Invasive ◽

Relationship Of ◽

The Relationship

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Longitudinal analysis of heart and liver iron in thalassemia major

Blood ◽

10.1182/blood-2008-04-148767 ◽

2008 ◽

Vol 112 (7) ◽

pp. 2973-2978 ◽

Cited By ~ 123

Author(s):

Leila J. Noetzli ◽

Susan M. Carson ◽

Anne S. Nord ◽

Thomas D. Coates ◽

John C. Wood

Keyword(s):

Longitudinal Analysis ◽

Time Lag ◽

Iron Concentration ◽

Thalassemia Major ◽

Iron Accumulation ◽

Liver Iron ◽

Cross Sectional ◽

Cardiac Iron ◽

Cardiac Iron Overload ◽

Magnetic Resonance Imaging Mri

Abstract High hepatic iron concentration (HIC) is associated with cardiac iron overload. However, simultaneous measurements of heart and liver iron often demonstrate no significant linear association. We postulated that slower rates of cardiac iron accumulation and clearance could reconcile these differences. To test this hypothesis, we examined the longitudinal evolution of cardiac and liver iron in 38 thalassemia major patients, using previously validated magnetic resonance imaging (MRI) techniques. On cross-sectional evaluation, cardiac iron was uncorrelated with liver iron, similar to previous studies. However, relative changes in heart and liver iron were compared with one another using a metric representing the temporal delay between them. Cardiac iron significantly lagged liver iron changes in almost half of the patients, implying a functional but delayed association. The degree of time lag correlated with initial HIC (r = 0.47, P < .003) and initial cardiac R2* (r = 0.57, P < .001), but not with patient age. Thus, longitudinal analysis confirms a lag in the loading and unloading of cardiac iron with respect to liver iron, and partially explains the weak cross-sectional association between these parameters. These data reconcile several prior studies and provide both mechanical and clinical insight into cardiac iron accumulation.

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Myocardial and Hepatic Iron Overload and Cardiac Function In Sickle/Thalassemia Patients Of Italian Origin

Blood ◽

10.1182/blood.v122.21.2252.2252 ◽

2013 ◽

Vol 122 (21) ◽

pp. 2252-2252

Author(s):

Antonella Meloni ◽

Giovan Battista Ruffo ◽

Daniele De Marchi ◽

Antonio Cardinale ◽

Anna Pietrapertosa ◽

...

Keyword(s):

Cardiac Function ◽

Iron Overload ◽

Conflicts Of Interest ◽

Iron Concentration ◽

Hepatic Iron ◽

Liver Iron ◽

Hepatic Iron Overload ◽

The Mean ◽

Magnetic Resonance Imaging Mri ◽

Italian Origin

Abstract Introduction Sickle-thalassemia results from the combined heterozygosity for sickle-cell and β-thalassemia genes. This study evaluates myocardial and hepatic iron overload and cardiac function in Italian patients and explores their correlation with transfusions, age and sex. Methods Fifty-nine sickle-thalassemia patients (29 males, mean age 35.6±14.1 years), enrolled in the MIOT network underwent magnetic resonance imaging (MRI). T2* value for all 16 myocardial segments and global heart T2* value were calculated. Hepatic T2* value was converted into liver iron concentration (LIC). Cine images were acquired to quantify biventricular volumes and ejection fraction (EF). Results 55 (93%) patients had all segmental T2* values normal (>20 ms). Of the 4 patients with abnormal segmental T2* values, all showed an heterogeneous myocardial iron overload (some segments with T2*>20 ms and other with T2*<20 ms) and only one had a global T2*<20 ms. The mean global heart T2* value was 34.4±6.2 ms. The mean LIC was 5.9±6.5 mg/g/dw and 30 patients (50.8%) had a pathological value (≥ 3 mg/g dw). There was a statistically significant positive correlation between global heart T2* and age but with poor linearity (R=0.368; P=0.004) and there was not a significant correlation between age and LIC. Males and females had comparable global heart T2* values and LIC values. Twenty patients were regularly transfused, 32 received sporadic transfusions while 7 were not transfused. The comparison among the three groups is shown in Table 1. We did not find significant differences in the global heart T2* value while patients regularly transfused had significantly higher LIC than sporadically transfused patients. Biventricular volumes indexed by body surface area and ejection fractions were comparable among the groups. Conclusions In respect of MIO, the sickle/thalassemia patients are similar to patients with homozygous SCD for which iron overloading is relatively rare. Hepatic iron overload may develop also in no regularly-transfused patients, maybe due to increased absorption of iron from the digestive tract, characteristic of both SCD and thalassemia intermedia patients. This finding underlines the importance to monitor by MRI also no regularly transfused sickle/thalassemia patients. Disclosures: No relevant conflicts of interest to declare.

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Flooding Reduces Gas Exchange and Growth in Snap Bean

HortScience ◽

10.21273/hortsci.26.4.372 ◽

1991 ◽

Vol 26 (4) ◽

pp. 372-373 ◽

Cited By ~ 12

Author(s):

Bharat P. Singh ◽

Kevin A. Tucker ◽

James D. Sutton ◽

Harbans L. Bhardwaj

Keyword(s):

Gas Exchange ◽

Net Photosynthesis ◽

Dry Weight ◽

Quadratic Model ◽

Snap Bean ◽

Blue Lake ◽

Relationship Of ◽

The Relationship ◽

Best Fit ◽

Prior Stress

This study was conducted to determine the effect of various flooding durations on the growth, water relations, and photosynthesis of the snap bean (Phaseolus vulgaris L.). Greenhouse-grown plants of cv. Blue Lake 274 were flooded for 0 (control), 1, 3, 5, or 7 days. Leaf water potential (ψ), stomatal conductance (gs), transpiration (E), and net photosynthesis (Pn) were measured at the completion of the flooding period and after recovery for 7 days. Root, stem, and leaf dry weights were recorded after plants were allowed to recover from the flooding stress for 7 days. The values for ψ, gs, E, and Pn decreased quadratically with the increase in the duration of flooding. The Pn of plants flooded for 1 day was 17% lower than that of the control and it reached near zero in plants flooded for 7 days. The decrease in Pn after 1 day of flooding was not associated with ψ or gs; however, for longer duration of flooding, Pn decline coincided with the decline in gs. A week after the cessation of flooding, the level of recovery in ψ, E, and Pn was linear and that in gs quadratic to the duration of prior stress experienced by the plant. However, after recovering for 7 days, none of the flooded plants regained gas exchange activities at par with the control. The relationship of stem dry weight to duration of flooding was linear, while a quadratic model provided the best fit for the regression of root and leaf dry weight on the number of days of flooding. Overall, even 1 day of flooding reduces photosynthesis in snap bean and causes a decrease in dry weight of the plant. the extent of decrease in both increasing with the duration of flooding.

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Human Vocal Tract Modeling and Geometric Parameterization

Advances in Bioengineering ◽

10.1115/imece2004-59662 ◽

2004 ◽

Author(s):

Hussain Z. Tameem ◽

Bhavin V. Mehta

Keyword(s):

Vocal Tract ◽

Three Dimensional ◽

Parametric Modeling ◽

Three Dimensional Model ◽

Non Invasive ◽

Solid Models ◽

Mri Scans ◽

Invasive Method ◽

Geometrical Information ◽

Magnetic Resonance Imaging Mri

This investigation uses a multi disciplinary approach to standardize a non-invasive method for measuring human vocal tract morphology. A series of Magnetic Resonance Imaging (MRI) scans are performed on the subject’s vocal tract and a detailed three-dimensional model is created through image processing and computer modeling. This information is compared with the vocal tract measurements obtained with Eccovision Acoustic Pharyngometer, in order to establish the accuracy of the instrument. The model is then used to develop other specific models through parametric modeling. This method is useful in creating solid models with limited geometrical information and helps researchers study the human vocal tract changes due to aging and degenerative diseases.

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