scholarly journals T1 mapping of the liver and the spleen in patients with liver fibrosis—does normalization to the blood pool increase the predictive value?

2020 ◽  
Author(s):  
Verena Carola Obmann ◽  
Annalisa Berzigotti ◽  
Damiano Catucci ◽  
Lukas Ebner ◽  
Christoph Gräni ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Liver Fibrosis ◽  
Portal Vein ◽  
Predictive Value ◽  
Good Predictor ◽  
Relaxation Times ◽  
Blood Pool ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Significant Liver Fibrosis

Abstract Purpose To analyze whether the T1 relaxation time of the liver is a good predictor of significant liver fibrosis and whether normalization to the blood pool improves the predictive value. Methods This prospective study was conducted between 03/2016 and 02/2018. One hundred seventy-three patients underwent multiparametric liver MRI at 3 T. The T1 relaxation time was measured in the liver and the spleen, in the aorta, the portal vein, and the inferior vena cava (IVC). T1 relaxation times with and without normalization to the blood pool were compared between patients with (n = 26) and without (n = 141) significant liver fibrosis, based on a cutoff value of 3.5 kPa in MRE as the noninvasive reference standard. For statistics, Student’s t test, receiver operating characteristic (ROC) curve analysis, and Pearson’s correlation were used. Results The T1 relaxation time of the liver was significantly longer in patients with liver fibrosis, both with and without blood pool normalization (p < 0.001). T1 relaxation time of the liver allowed prediction of significant liver fibrosis (AUC = 0.88), while normalization to the IVC resulted in a slightly lower performance (AUC = 0.82). The lowest performance was achieved when the T1 relaxation times of the liver were normalized to the aorta (AUC = 0.66) and to the portal vein (AUC = 0.62). The T1 relaxation time of the spleen detected significant liver fibrosis with an AUC of 0.68, and 0.51–0.64 with normalization to the blood pool. Conclusion The T1 relaxation time of the liver is a good predictor of significant liver fibrosis. However, normalization of the blood pool did not improve the predictive value. Key Points • The T1 relaxation time of the liver is a good predictor of significant liver fibrosis. • Normalization to the blood pool did not improve the predictive value of T1 mapping. • If the blood pool normalization was weighted 30% to the aorta and 70% to the portal vein, the performance was better than normalization to the aorta alone but still lower than normalization to the IVC.

MTR and T1 provide complementary information in MS NAWM, but not in lesions

2000 ◽  
Vol 6 (5) ◽  
pp. 327-331 ◽  
Author(s):  
C M Griffin ◽  
G JM Parker ◽  
G J Barker ◽  
A J Thompson ◽  
D H Miller
Keyword(s):  
Relaxation Time ◽  
White Matter ◽  
Mixed Model ◽  
Relaxation Times ◽  
Tissue Type ◽  
Tissue Characterisation ◽  
Complementary Information ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
The Relationship

MTR and T1 relaxation times are abnormal in MS lesions and NAWM, and may reflect tissue damage such as demyelination and axonal loss. Their relationship and potential to provide complementary information in tissue characterisation is explored. The aim of this study was to document the relationship between magnetisation transfer ratio (MTR) and T1 relaxation time in Multiple Sclerosis (MS) lesions and normal appearing white matter (NAWM) in order to determine whether the combination provides a more comprehensive tissue characterisation than either parameter in isolation. Ten patients with relapsing remitting MS and 10 age matched healthy controls underwent imaging using a protocol which included the measurement of both MTR and T1 relaxation times. The MTR and T1 values were compared statistically using a commonly adopted correlation approach and a mixed-model regression approach. There was a strong correlation between MTR and T1 in MS lesions (r=0.74). The correlation was seen equally in T1 hypointense and isointense lesions. The relationship was much weaker in MS NAWM (r=0.24) and no correlation was found in control white matter (r=0.06). Mixed-model regression analysis confirmed that the relationship between T1 and MTR is strongly dependent upon tissue type (MS lesion, MS NAWM, or control white matter). The relationship between MTR and T1 relaxation time measurements varies markedly between pathological and normal tissue types. In MS, the complementary information obtained from MTR and T1 is most apparent in NAWM. The results emphasise the potential for combinations of MR parameters to improve tissue characterisation, which in turn should improve understanding of disease pathology and treatment monitoring.

Single- vs. double-dose gadolinium contrast in delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) in knee osteoarthritis: is dose reduction possible on 3-T MRI?

2018 ◽  
Vol 60 (6) ◽  
pp. 749-754
Author(s):  
Stine Hangaard ◽  
Jesper Sörensson Gade ◽  
Philip Hansen ◽  
Janus Damm Nybing ◽  
Henrik Gudbergsen ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Single Dose ◽  
Knee Osteoarthritis ◽  
Weight Bearing ◽  
Relaxation Times ◽  
Lateral Compartment ◽  
Double Dose ◽  
Gadolinium Contrast ◽  
T1 Relaxation Time ◽  
T1 Relaxation

Background Reduction in gadolinium (Gd) contrast agents is wanted due to the uncertainty of the potential side effects. Purpose To investigate whether it is possible to reduce the contrast dose from conventional double dose to single dose when increasing the field strength from 1.5-T to 3-T for separating early cartilage degeneration from healthy cartilage, assessed by delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). Material and Methods Nine patients with knee osteoarthritis (OA), Kellgren–Lawrence grade (KLG) 1–4, were recruited from an ongoing weight loss cohort study. dGEMRIC was performed at 3-T using single (0.1 mmoI/kg) and double (0.2 mmoI/kg) doses of intravenous (i.v.) Gd-DTPA2-. Regions of interest (ROls) were drawn around the posterior weight-bearing femoral knee cartilage in lateral and medial compartments. In five medial compartments ROIs could not be drawn due to severe degeneration of cartilage. T1-relaxation times were compared to previously published values from 1.5-T and to non-contrast values from 3-T. Results Mean dGEMRIC T1-relaxation time in the lateral compartment was 769 ms for single dose vs. 561 ms for double dose ( P < 0.0001); and 685 ms for single dose vs. 454 ms for double dose ( P = 0.004) in the medial compartment. Conclusion We found a dose-response relationship between single and double doses of Gd-DTPA2- using 3-T in knee OA patients, similar to the findings at 1.5-T. Compared to the T1-relaxation time at 3-T without contrast (1240 ms), this further separation between OA and normal cartilage indicates that “single dose” dGEMRIC could be sufficient for cartilage health assessment at 3-T.

scholarly journals Precision of T1-relaxation time measurements in the hepatic portal vein: influence of measurement technique and sequence parameters

2019 ◽  
Vol 32 (3) ◽  
pp. 359-368 ◽  
Author(s):  
Svein Are Sirirud Vatnehol ◽  
Per Kristian Hol ◽  
Atle Bjørnerud ◽  
Mahmood Amiry-Moghaddam ◽  
Camilla Haglerød ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Portal Vein ◽  
Measurement Technique ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Hepatic Portal Vein ◽  
Hepatic Portal ◽  
Sequence Parameters

scholarly journals Longer sustained Fontan circulation is associated with prolonged hepatic T1 relaxation time on T1 mapping

2021 ◽  
Vol 22 (Supplement_2) ◽  
Author(s):  
A Yanovskiy ◽  
T Ojala ◽  
R Kivisaari ◽  
L Martelius
Keyword(s):  
Relaxation Time ◽  
Liver Disease ◽  
T1 Mapping ◽  
Single Ventricle ◽  
Venous Pressure ◽  
Relaxation Times ◽  
Hemodynamic Parameters ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Systemic Ventricle

Abstract Funding Acknowledgements Type of funding sources: None. Background Patients with single ventricle defects may develop Fontan-associated liver disease. T1 mapping has been successfully used for evaluating chronic liver disease in adults. Liver T1 mapping has been also studied in the pediatric patients with single ventricles, and these patients show higher T1 relaxation times compared to the healthy controls. Purpose Our objective was to study the relationship between the cardiac MRI (CMR) T1 mapping relaxation time of the liver and 1) CMR derived hemodynamic parameters, 2) peripheral venous pressure (PVP) measured from a cubital cannula 3) systemic ventricle morphology [LV vs. RV], 4) the age of patient, and 5) alanine transaminase (P-ALAT) levels. Methods This retrospective study included 46 patients with functional single ventricle, which underwent routine CMR at our hospital. Table 1 shows demographic and clinical data of the study population. Statistical analysis were performed with IBM SPSS Statistics v.25 software using independent samples t test, Mann-Whitney U-test or Pearson correlation as appropriate. A p-value less than 0.05 was considered significant. Results The average T1 relaxation time of the liver was longer in patients with RV morphology (p = 0.004). There was a significant moderate positive correlation between the age of the patients and hepatic T1 relaxation time (r = 0.45, p = 0.002), and between hepatic T1 relaxation time and P-ALAT levels (r = 0.5, p = 0.016) (Fig.1).  No significant correlations were detected between the T1 times of the liver and hemodynamic parameters of the heart (all tested parameters are listed in the Table1). Ejection fraction and PVP showed a non-significant weak correlation with a hepatic T1 relaxation times (r=-0.3, p = 0,056 and r = 0.3, p = 0,070, respectively). Conclusions  T1 mapping times of the liver may reflect Fontan-associated liver disease. We observed connections between the hepatic T1 relaxation times and 1) patients age, 2) systemic ventricle morphology and 3) P-ALAT levels.

scholarly journals Magnetic Resonance Relaxometry for Tumor Cell Density Imaging for Glioma: An Exploratory Study via 11C-methionine PET and Its Validation via Stereotactic Tissue Sampling

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4067
Author(s):  
Manabu Kinoshita ◽  
Masato Uchikoshi ◽  
Souichiro Tateishi ◽  
Shohei Miyazaki ◽  
Mio Sakai ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Magnetic Resonance ◽  
Tumor Cell ◽  
Relaxation Times ◽  
Tissue Sampling ◽  
T2 Relaxation ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Tumor Load ◽  
T1 And T2

One of the most crucial yet challenging issues for glioma patient care is visualizing non-contrast-enhancing tumor regions. In this study, to test the hypothesis that quantitative magnetic resonance relaxometry reflects glioma tumor load within tissue and that it can be an imaging surrogate for visualizing non-contrast-enhancing tumors, we investigated the correlation between T1- and T2-weighted relaxation times, apparent diffusion coefficient (ADC) on magnetic resonance imaging, and 11C-methionine (MET) on positron emission tomography (PET). Moreover, we compared the T1- and T2-relaxation times and ADC with tumor cell density (TCD) findings obtained via stereotactic image-guided tissue sampling. Regions that presented a T1-relaxation time of >1850 ms but <3200 ms or a T2-relaxation time of >115 ms but <225 ms under 3 T indicated a high MET uptake. In addition, the stereotactic tissue sampling findings confirmed that the T1-relaxation time of 1850–3200 ms significantly indicated a higher TCD (p = 0.04). However, ADC was unable to show a significant correlation with MET uptake or with TCD. Finally, synthetically synthesized tumor load images from the T1- and T2-relaxation maps were able to visualize MET uptake presented on PET.

scholarly journals Extracellular volume quantification using synthetic haematocrit assessed from native and post-contrast longitudinal relaxation T1 times of a blood pool

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lukas Opatril ◽  
Roman Panovsky ◽  
Jan Machal ◽  
Tomas Holecek ◽  
Lucia Masarova ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Relaxation Times ◽  
Extracellular Volume Fraction ◽  
Blood Pool ◽  
Coefficient Of Determination ◽  
Post Contrast ◽  
T1 Relaxation ◽  
Before And After

Abstract Background In terms of cardiovascular magnetic resonance are haematocrit values required for calculation of extracellular volume fraction (ECV). Previously published studies have hypothesized that haematocrit could be calculated from T1 blood pool relaxation time, however only native T1 relaxation time values have been used and the resulting formulae had been both in reciprocal and linear proportion. The aim of the study was to generate a synthetic haematocrit formula from only native relaxation time values first, calculate whether linear or reciprocal model is more precise in haematocrit estimation and then determine whether adding post-contrast values further improve its precision. Methods One hundred thirty-nine subjects underwent CMR examination. Haematocrit was measured using standard laboratory methods. Afterwards T1 relaxation times before and after the application of a contrast agent were measured and a statistical relationship between these values was calculated. Results Different linear and reciprocal models were created to estimate the value of synthetic haematocrit and ECV. The highest coefficient of determination was observed in the combined reciprocal model “− 0.047 + (779/ blood native) − (11.36/ blood post-contrast)”. Conclusions This study provides more evidence that assessing synthetic haematocrit and synthetic ECV is feasible and statistically most accurate model to use is reciprocal. Adding post-contrast values to the calculation was proved to improve the precision of the formula statistically significantly.

scholarly journals Extracellular Volume Quantification using Synthetic Haematocrit Assessed from Native and Post-contrast Longitudinal Relaxation T1 Times of a Blood Pool

2021 ◽  
Author(s):  
Lukas Opatril ◽  
Roman Panovsky ◽  
Jan Machal ◽  
Tomas Holecek ◽  
Lucia Masarova ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Relaxation Times ◽  
Extracellular Volume Fraction ◽  
Blood Pool ◽  
Coefficient Of Determination ◽  
Post Contrast ◽  
T1 Relaxation ◽  
Before And After

Abstract Background: In terms of cardiovascular magnetic resonance are haematocrit values required for calculation of extracellular volume fraction (ECV). Previously published studies have hypothesized that haematocrit could be calculated from T1 blood pool relaxation time, however only native T1 relaxation time values have been used and the resulting formulae had been both in reciprocal and linear proportion. The aim of the study was to generate a synthetic haematocrit formula from only native relaxation time values first, calculate whether linear or reciprocal model is more precise in haematocrit estimation and then determine whether adding post-contrast values further improve its precision.Methods: One hundred thirty-nine subjects underwent CMR examination. Haematocrit was measured using standard laboratory methods. Afterwards T1 relaxation times before and after the application of a contrast agent were measured and a statistical relationship between these values was calculated.Results: Different linear and reciprocal models were created to estimate the value of synthetic haematocrit and ECV. The highest coefficient of determination was observed in the combined reciprocal model “-0.047 + (779/ blood native) – (11.36/ blood post-contrast)”.Conclusions: This study provides more evidence that assessing synthetic haematocrit and synthetic ECV is feasible and statistically most accurate model to use is reciprocal. Adding post-contrast values to the calculation was proved to improve the precision of the formula statistically significantly.

T1 Relaxation Time of Achilles Tendon at 3 Tesla with Special Reference to Relevant Clinical Score: A Preliminary Study

2020 ◽  
Vol 16 (2) ◽  
pp. 164-173
Author(s):  
Zeineb Tbini ◽  
Mokhtar Mars ◽  
Mouna Bouaziz
Keyword(s):  
Relaxation Time ◽  
Achilles Tendon ◽  
Clinical Score ◽  
3 Tesla ◽  
Acquisition Time ◽  
Short Term ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Spin Echo Sequence ◽  
Significant Difference

Purpose: The purpose of this study was to investigate T1 relaxation time of the human Achilles tendon, to test its short-term repeatability as well as the minimal detectable change, and to assess the extent that correlate with clinical symptoms. Methods: Twenty asymptomatic volunteers and eighteen patients with clinically and sonographically confirmed tendinopathy were scanned for ankle using a 3 Tesla (T) MR scanner. T1 maps were calculated from a variable flip angle gradient echo Ultra-short echo time sequence (VFA-GE UTE) and inversion recovery spin echo sequence (IR-SE) using a self-developed matlab algorithm in three regions of interest of Achilles Tendon (AT). Signal to Noise Ratio (SNR) between the two sequences was evaluated. INTRA-class Correlation Coefficient (ICC), Coefficient of Variation (CV) and the Least Significant Change (LSC) were calculated, to test short-term repeatability of T1. Subjects were assessed by the VISA-A clinical score. P values less than 0.005 were considered statistically significant. Results: Mean T1 values were 427.09 ± 53.37 ms and 528.70 ± 103.50 ms using IR-SE sequence and 575.43 ± 110.60 ms and 875.81 ± 425.77 ms with VFA-GE UTE sequence in the whole AT for volunteers and patients, respectively. : T1 values showed a significant difference between volunteers and patients (P=0.001). Regional variation of T1 in healthy and tendinopathic AT were greater for VFA-GE UTE sequence than for IR-SE sequence. VFA-GE UTE sequence showed clearly higher SNR compared to IR-SE sequence. Short-term repeatability of T1 values for volunteers showed an LSC of 22% and 14% for IR-SE sequence and VFA-GE UTE sequence, respectively. For patients, LSC was 14% and 5% for IR-SE sequence and VFA-GE UTE sequence, respectively. There was no correlation between T1 and VISA-A clinical score (p>0.005). Conclusion: VFA-GE UTE sequence used for T1 mapping calculation demonstrated short acquisition time and clearly high SNR. Results revealed that T1 relaxation time can be used as a biomarker to differentiate between healthy and pathologic Achilles tendon. However, T1 showed no correlation with the VISA-A clinical score.

Sign in / Sign up

Export Citation Format

Share Document