T1 and T2 Mappings in the Early Diagnosis of Achilles Tendinosis

Objective: The purpose of this study was to compare T1 and T2 relaxation times of normal and pathologic Achilles Tendon (AT) in order to evaluate the ability of these methods to detect early Achilles tendon tendinosis. Materials and Methods: Forty-eight subjects were included in this study. Twenty-two subjects were classified as normal group and twenty-six subjects as patient group with tendinosis. MR examination was performed by 3 Tesla scanner using a 12 channel head coil. For relaxation times quantification, we used a sagittal 3D FLASH variable flip angle gradient echo UTE sequence (3D VFA-GE UTE) for T1 mapping and a sagittal Multi Echo Spin Echo sequence (MESE) for T2 mapping. Relaxation times were quantified using two different algorithms written in MATLAB. P value < 0.05 was considered statistically significant. Results: Our results showed a statistically significant difference in T1 and T2 values for the normal group compared to the patient group (p<0.05). Mean values of T1 and T2 were 571.69 ms and 24.16 ms for the normal group and 818.10 ms and 32.43 ms for the patient group, respectively. Results reported no correlation (r=0.193) for T1 mapping and a positive significant moderate correlation (r=0.542, p=0.000) for T2 mapping between the normal and patient groups. T1 and T2 showed no correlation in the normal group (r= 0.091, p=0.489) and a positive significant weak correlation in the patient group (r=0.263, p=0.048). Conclusion: We concluded that T1 and T2 relaxation times are relatively sensitive to diagnosis degenerative changes in the AT and T1 is more sensitive to AT tendinosis compared to T2.

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Myocardial Mapping in Systemic Sarcoidosis: A Comparison of Two Measurement Approaches

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren ◽

10.1055/a-1174-0537 ◽

2020 ◽

Vol 193 (01) ◽

pp. 68-76

Author(s):

Darius Dabir ◽

Julian Luetkens ◽

Daniel Kuetting ◽

Jennifer Nadal ◽

Hans Heinz Schild ◽

...

Keyword(s):

T1 Mapping ◽

Tissue Characterization ◽

Cardiac Involvement ◽

T2 Mapping ◽

Relaxation Times ◽

Short Axis Slice ◽

T2 Relaxation ◽

Standard Mapping ◽

Systemic Sarcoidosis ◽

T1 And T2

Purpose To investigate if T1 and T2 mapping is able to differentiate between diseased and healthy myocardium in patients with systemic sarcoidosis, and to compare the standard mapping measurement (measurement within the whole myocardium of the midventricular short axis slice, SAX) to a more standardized method measuring relaxation times within the midventricular septum (ConSept). Materials and Methods 24 patients with biopsy-proven extracardiac sarcoidosis and 17 healthy control subjects were prospectively enrolled in this study and underwent CMR imaging at 1.5 T including native T1 and T2 mapping. Patients were divided into patients with (LGE+) and without (LGE–) cardiac sarcoidosis. T1 and T2 relaxation times were compared between patients and controls. Furthermore, the SAX and the ConSept approach were compared regarding differentiation between healthy and diseased myocardium. Results T1 and T2 relaxation times were significantly longer in all patients compared with controls using both the SAX and the ConSept approach (p < 0.05). However, LGE+ and LGE– patients showed no significant differences in T1 and T2 relaxation times regardless of the measurement approach used (ConSept/SAX) (p > 0.05). Direct comparison of ConSept and SAX T1 mapping showed high conformity in the discrimination between healthy and diseased myocardium (Kappa = 0.844). Conclusion T1 and T2 mapping may not only enable noninvasive recognition of cardiac involvement in patients with systemic sarcoidosis but may also serve as a marker for early cardiac involvement of the disease allowing for timely treatment. ConSept T1 mapping represents an equivalent method for tissue characterization in this population compared to the SAX approach. Further studies including follow-up examinations are necessary to confirm these preliminary results. Key Points: Citation Format

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Multiparametric Cardiovascular Magnetic Resonance in Acute Myocarditis: Comparison of 2009 and 2018 Lake Louise Criteria With Endomyocardial Biopsy Confirmation

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.739892 ◽

2021 ◽

Vol 8 ◽

Author(s):

Shuang Li ◽

Xuejing Duan ◽

Guangxun Feng ◽

Arlene Sirajuddin ◽

Gang Yin ◽

...

Keyword(s):

Magnetic Resonance ◽

Endomyocardial Biopsy ◽

Diagnostic Performance ◽

T1 Mapping ◽

Acute Myocarditis ◽

T2 Mapping ◽

Relaxation Times ◽

T2 Relaxation ◽

3.0 T ◽

Combined Parameters

Background: Cardiac magnetic resonance (CMR) has been shown to improve the diagnosis of myocarditis, but no systematic comparison of this technique is currently available. The purpose of this study was to compare the 2009 and 2018 Lake Louise Criteria (LLC) for the diagnosis of acute myocarditis using 3.0 T MRI with endomyocardial biopsy (EMB) as a reference and to provide the cutoff values for multiparametric CMR techniques.Methods: A total of 73 patients (32 ± 14 years, 71.2% men) with clinically suspected myocarditis undergoing EMB and CMR with 3.0 T were enrolled in the study. Patients were divided into two groups according to EMB results (EMB-positive and -negative groups). The CMR protocol consisted of cine-SSFP, T2 STIR, T2 mapping, early and late gadolinium enhancement (EGE, LGE), and pre- and post-contrast T1 mapping. Their potential diagnostic ability was assessed with receiver operating characteristic curves.Results: The myocardial T1 and T2 relaxation times were significantly higher in the EMB-positive group than in the EMB-negative group. Optimal cutoff values were 1,228 ms for T1 relaxation times and 58.5 ms for T2 relaxation times with sensitivities of 86.0 and 83.7% and specificities of 93.3 and 93.3%, respectively. The 2018 LLC had a better diagnostic performance than the 2009 LLC in terms of sensitivity, specificity, positive predictive value, and negative predictive value. T1 mapping + T2 mapping had the largest area under the curve (0.95) compared to other single or combined parameters (2018 LLC: 0.91; 2009 LLC: 0.76; T2 ratio: 0.71; EGEr: 0.67; LGE: 0.73; ). The diagnostic accuracy for the 2018 LLC was the highest (91.8%), followed by T1 mapping (89.0%) and T2 mapping (87.7%).Conclusion: Emerging technologies such as T1/ T2 mapping have significantly improved the diagnostic performance of CMR for the diagnosis of acute myocarditis. The 2018 LLC provided the overall best diagnostic performance in acute myocarditis compared to other single standard CMR parameters or combined parameters. There was no significant gain when 2018LLC is combined with the EGE sequence.

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

Current Medical Imaging Formerly Current Medical Imaging Reviews ◽

10.2174/1573405615666181205130816 ◽

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.

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Determining the effect of water temperature on the T1 and T2 relaxation times of the lung tissue at 9.4 T MRI: A drowning mouse model

Legal Medicine ◽

10.1016/j.legalmed.2020.101836 ◽

2021 ◽

pp. 101836

Author(s):

Kodama Saki ◽

Hata Junichi ◽

Kanawaku Yoshimasa ◽

Nakagawa Hiroshi ◽

Oshiro Hinako ◽

...

Keyword(s):

Mouse Model ◽

Water Temperature ◽

Lung Tissue ◽

Relaxation Times ◽

T2 Relaxation ◽

Effect Of Water ◽

T1 And T2

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Evaluation of Relaxation Time Measurements by Magnetic Resonance Imaging

Acta Radiologica ◽

10.1177/028418518702800323 ◽

1987 ◽

Vol 28 (3) ◽

pp. 345-351 ◽

Cited By ~ 20

Author(s):

L. Kjær ◽

C. Thomsen ◽

O. Henriksen ◽

P. Ring ◽

M. Stubgaard ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Relaxation Time ◽

Magnetic Resonance ◽

Diffusion Processes ◽

Relaxation Times ◽

Gradient Field ◽

Maximum Deviation ◽

Resonance Imaging ◽

T2 Relaxation ◽

T1 And T2

Several circumstances may explain the great variation in reported proton T1 and T2 relaxation times usually seen. This study was designed to evaluate the accuracy of relaxation time measurements by magnetic resonance imaging (MRI) operating at 1.5 tesla. Using a phantom of nine boxes with different concentrations of CuSO4 and correlating the calculated T1 and T2 values with reference values obtained by two spectrometers (corrected to MRI-proton frequency=64 MHz) we found a maximum deviation of about 10 per cent. Measurements performed on a large water phantom in order to evaluate the homogeneity in the imaging plane showed a variation of less than 10 per cent within 10 cm from the centre of the magnet in all three imaging planes. Changing the gradient field strength apparently had no influence on the T2 values recorded. Consequently diffusion processes seem without significance. It is concluded that proton T1 and T2 relaxation times covering the majority of the biologic range can be measured by MRI with an overall accuracy of 5 to 10 per cent. Quality control studies along the lines indicated in this study are recommended.

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Disease Detection By MR Imaging: T1 And T2 Relaxation Times

Cell Function and Disease ◽

10.1007/978-1-4613-0813-3_37 ◽

1988 ◽

pp. 415-420

Author(s):

Luis E. Todd ◽

Guillermo Elizondo ◽

Ralph Weissleder

Keyword(s):

Mr Imaging ◽

Relaxation Times ◽

Disease Detection ◽

T2 Relaxation ◽

T1 And T2

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The Effect of Intraventricular Hemorrhage on Brain Development in Premature Infants: A Synthetic MRI Study

Frontiers in Neurology ◽

10.3389/fneur.2021.721312 ◽

2021 ◽

Vol 12 ◽

Author(s):

Chunxiang Zhang ◽

Xin Zhao ◽

Meiying Cheng ◽

Kaiyu Wang ◽

Xiaoan Zhang

Keyword(s):

Relaxation Time ◽

Premature Infants ◽

Intraventricular Hemorrhage ◽

Brain Volume ◽

Relaxation Times ◽

T2 Relaxation Time ◽

T2 Relaxation ◽

T1 And T2 ◽

The Brain ◽

Synthetic Mri

Objectives: Synthetic MRI can obtain multiple parameters in one scan, including T1 and T2 relaxation time, proton density (PD), brain volume, etc. This study aimed to investigate the parameter values T1 and T2 relaxation time, PD, and volume characteristics of intraventricular hemorrhage (IVH) newborn brain, and the ability of synthetic MRI parameters T1 and T2 relaxation time and PD to diagnose IVH.Materials and methods: The study included 50 premature babies scanned with conventional and synthetic MRI. Premature infants were allocated to the case group (n = 15) and NON IVH (n = 35). The T1, T2, PD values, and brain volume were obtained by synthetic MRI. Then we assessed the impact of IVH on these parameters.Results: In the posterior limbs of the internal capsule (PLIC), genu of the corpus callosum (GCC), central white matter (CWM), frontal white matter (FWM), and cerebellum (each p < 0.05), the T1 and T2 relaxation times of the IVH group were significantly prolonged. There were significant differences also in PD. The brain volume in many parts were also significantly reduced, which was best illustrated in gray matter (GM), cerebrospinal fluid and intracranial volume, and brain parenchymal fraction (BPF) (each p < 0.001, t = −5.232 to 4.596). The differential diagnosis ability of these quantitative values was found to be excellent in PLIC, CWM, and cerebellum (AUC 0.700–0.837, p < 0.05).Conclusion: The quantitative parameters of synthetic MRI show well the brain tissue characteristic values and brain volume changes of IVH premature infants. T1 and T2 relaxation times and PD contribute to the diagnosis and evaluation of IVH.

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Reliability of Synthetic Brain MRI for Assessment of Ischemic Stroke with Phantom Validation of a Relaxation Time Determination Method

Journal of Clinical Medicine ◽

10.3390/jcm9061857 ◽

2020 ◽

Vol 9 (6) ◽

pp. 1857

Author(s):

Chia-Wei Li ◽

Ai-Ling Hsu ◽

Chi-Wen C. Huang ◽

Shih-Hung Yang ◽

Chien-Yuan Lin ◽

...

Keyword(s):

Ischemic Stroke ◽

Relaxation Time ◽

Brain Mri ◽

Relaxation Times ◽

Onset Time ◽

Magnetic Resonance Images ◽

Diagnostic Tools ◽

Cupric Sulfate ◽

T2 Relaxation ◽

T1 And T2

The reliability of relaxation time measures in synthetic magnetic resonance images (MRIs) of homemade phantoms were validated, and the diagnostic suitability of synthetic imaging was compared to that of conventional MRIs for detecting ischemic lesions. Phantoms filled with aqueous cupric-sulfate (CuSO4) were designed to mimic spin-lattice (T1) and spin-spin (T2) relaxation properties and were used to compare their accuracies and stabilities between synthetic and conventional scans of various brain tissues. To validate the accuracy of synthetic imaging in ischemic stroke diagnoses, the synthetic and clinical scans of 18 patients with ischemic stroke were compared, and the quantitative contrast-to-noise ratios (CNRs) were measured, using the Friedman test to determine significance in differences. Results using the phantoms showed no significant differences in the interday and intersession synthetic quantitative T1 and T2 values. However, between synthetic and referenced T1 and T2 values, differences were larger for longer relaxation times, showing that image intensities in synthetic scans are relatively inaccurate in the cerebrospinal fluid (CSF). Similarly, CNRs in CSF regions of stroke patients were significantly different on synthetic T2-weighted and T2-fluid-attenuated inversion recovery images. In contrast, differences in stroke lesions were insignificant between the two. Therefore, interday and intersession synthetic T1 and T2 values are highly reliable, and discrepancies in synthetic T1 and T2 relaxation times and image contrasts in CSF regions do not affect stroke lesion diagnoses. Additionally, quantitative relaxation times from synthetic images allow better estimations of ischemic stroke onset time, consequently increasing confidence in synthetic MRIs as diagnostic tools for ischemic stroke.

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