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BACKGROUND: Lumbar facet arthritis is one of the main causes of low back pain. At present, MRI is mainly used for preliminary diagnosis, and there is still a certain probability of missed diagnosis and misdiagnosis. Therefore, MR T2* mapping imaging technology is expected to become an important means of quantitative detection of cartilage damage in lumbar facet arthritis. OBJECTIVE: To investigate the application value of MR T2* mapping imaging technique in quantitative analysis of cartilage damage and degeneration of lumbar facet joint. METHODS: A total of 110 outpatient or inpatient patients with low back pain in Fourth Affiliated Hospital of Nanjing Medical University from April 2020 to March 2022 were collected and set as case group. At the same time, 80 asymptomatic volunteers were recruited as the control group. T2* mapping transectal images and T2WI images were obtained by 3.0T MR Scanning for the facet joints of all included subjects L1-S1. Weishaupt grading and T2* value measurement were performed for all facet joint cartilage, and the data were collected for parallel statistical analysis. The comparison of T2* values of facet joint cartilage between different articular Weishaupt grades was performed by one-way analysis of variance. RESULTS AND CONCLUSION: (1) Statistical analysis found that the T2* value of lumbar facet joint cartilage in the case group (17.6±1.5) ms was significantly lower than that in the control group (21.4±1.3) ms (P < 0.05). (2) In the case group, with the hierarchical increase of lumbar facet joint Weishaupt, the T2* value of facet joint cartilage also showed a gradual decreasing trend, and the difference was statistically significant (P < 0.05). (3) It is concluded that T2* mapping can better display the early pathological changes of lumbar facet joint cartilage injury, and T2* value of lumbar facet joint cartilage can quantitatively evaluate the degree of lumbar facet joint cartilage injury. T2* mapping imaging technique can provide a good theoretical basis for the imaging diagnosis of the early cartilage injury induced by lumbar facet arthritis and has important clinical application value. [ABSTRACT FROM AUTHOR]

Objective: Inflammatory cardiomyopathy is a disease associated with cardiac dysfunction and ventricular remodeling. Among the most recent diagnostic methods available, histologic characterization through cardiac magnetic resonance imaging (MRI) is used to identify inflammatory changes. Multiple studies have evaluated autoimmune mechanisms in myocardium damage following COVID-19, begging how feasible it is to differentiate and characterize lesions found in post-COVID-19 inflammatory cardiomyopathy. Method: Retrospective study comparing 29 MRI studies (12 diagnosed with post-COVID-19 inflammatory cardiomyopathy and 17 previously diagnosed with autoimmune cardiomyopathy, rheumatoid arthritis, scleroderma, or systemic lupus erythematosus), comparing the histologic characterization of T1, T2 mapping and extracellular volume (ECV) through cardiac MRI. Results: Post-COVID-19 inflammatory cardiomyopathy histologic characterization did not show significant differences compared to autoimmune myocardial lesions. T1 mapping 1109 ± 76 ms, T2 mapping 58 ± 6 ms, ECV 41 ± 9%. Myocardial lesions occurring from an autoimmune etiology showed: T1 mapping 1132 ± 122 ms, T2 mapping 61 ± 4 ms, and ECV 38 ± 8% (p > 0.05). Conclusion: T1-T2 mapping and ECV are similar among patients with post-COVID-19 inflammatory cardiomyopathy and myocardial damage secondary to autoimmune diseases, as there seem to exist similar pathologic mechanisms presenting in both groups, consistent with current literature regarding myocardial damage in SARS-CoV-2 infections. [ABSTRACT FROM AUTHOR]

Objective: Cartilage and meniscus are important structures that maintain the health of the knee joint. Early detection of changes in the internal components of cartilage and meniscus before morphological changes occur is essential to prevent and delay the development of osteoarthritis (OA). This study was designed to determine the changes in the matrix composition of morphologically intact cartilage and meniscus during the acute phase of an anterior cruciate ligament (ACL) rupture, as well as the effect of different states of meniscus (intact or tear) on adjacent cartilage during the acute phase. Methods: This cross‐sectional study compared and analyzed 50 patients in the acute phase of ACL rupture who underwent surgical treatment and 66 age‐, weight‐ and height‐matched healthy volunteers from May 2022 to May 2023 at our institution. Mean T2 relaxation times and effect sizes in different regions of tibiofemoral articular cartilage and meniscus were compared between the two groups using the Mann–Whitney nonparametric t‐test, and correlations between different meniscal states and adjacent cartilage were analyzed. Results: Both in the lateral and medial compartments of the knee, T2 relaxation times were significantly higher in all subregions of cartilage and meniscus in the ACL rupture group (p < 0.05), and the site of injury was predominantly centered in the medial compartment (femur, p = 0.000; tibia, p = 0.000; anterior horn, p = 0.000). In the respective compartments, the posterior horn of the lateral meniscus showed a significant positive correlation with the mid‐cartilage of the femoral and tibial (r = 0.566, p = 0.035; r = 0.611, p = 0.02); and the posterior horn of the medial meniscus showed a significant positive correlation with the posterior tibial cartilage (r = 0.668, p = 0.018). Conclusion: During the acute phase of ACL rupture, the internal composition of the cartilage and meniscus undergoes significant changes, even if the morphology is intact. More importantly, the state of the meniscus significantly affects the internal composition of the adjacent cartilage. This is an early warning sign of OA, which should be closely monitored and carefully managed in clinical practice. [ABSTRACT FROM AUTHOR]

It is known that microtrauma exists in the thigh muscles after long‐distance running such as the half‐marathon. Moreover, training characteristics of long‐distance runners may influence the specificity of the distribution of muscle fiber types in the thigh and affect muscle responses to lipid metabolism. However, the specific changes in microtrauma and intramuscular lipid in thigh muscles after a half‐marathon are unknown. A cohort of 20 healthy recreational marathon runners was recruited to complete a half‐marathon. MRI T2 mapping and 6‐echo q‐Dixon sequences were employed at baseline (P1), 2–3 h after running (P2), and 1 day after running (P3). Inflammatory markers (the T2 values) and intramuscular fat fraction (the proton density fat fraction, PDFF) were measured in thigh muscles to detect microtrauma and intramuscular lipid changes, respectively. One‐way analysis of variance showed significant time effects for T2 values and PDFF. Post hoc analysis of the 14 datasets collected at three time points revealed significantly higher T2 values in all thigh muscles after running (all p < 0.05). Significant differences in T2 values persisted for all thigh muscles at P3 compared to P1 (all p < 0.05). The PDFF of the vastus lateralis and vastus medialis was significantly decreased at P2 compared to P1 (p < 0.05). No significant differences in PDFF were observed for the thigh muscles at P3 compared to P1. The manifestations of inflammation edema and intramuscular lipid investigated through MRI may offer valuable insights for recreational marathon runners regarding the lower limb movement characteristics during half‐marathon running. Highlights: Magnetic resonance imaging (MRI) technology stands as a valuable noninvasive tool for the observation of musculature.Utilizing MRI T2 mapping and 6‐echo q‐Dixon sequences facilitates the examination of inflammatory edema resulting from endurance exercise along with intramuscular lipid changes.The manifestations of inflammation edema and intramuscular lipid investigated through MRI may unveil novel perspectives on the movement characteristics of lower limbs in recreational marathon runners. [ABSTRACT FROM AUTHOR]

Myocardial injury after noncardiac surgery (MINS) and perioperative myocardial injury are associated with increased morbidity and mortality. Both are diagnosed by a perioperative increase in troponin, yet there is controversy if MINS is a genuine myocardial insult. We applied postoperative cardiovascular magnetic resonance T2 mapping techniques to visualise acute myocardial injury (i.e. oedema) in six patients with multiple cardiovascular risk factors who underwent aortic surgery. The burden of myocardial oedema was substantially higher in four patients with elevated troponin qualifying for MINS, compared with patients without MINS. The data and images suggest that MINS represents genuine myocardial injury. [ABSTRACT FROM AUTHOR]

Detecting ongoing inflammation in myocarditis patients has prognostic relevance, but there are limited data on the detection of chronic myocarditis and its differentiation from healed myocarditis. This study sought to assess the performance of cardiac magnetic resonance (CMR) for the detection of ongoing inflammation and the discrimination of chronic myocarditis from healed myocarditis. Consecutive patients with persistent symptoms (>30 days) suggestive of myocarditis were prospectively enrolled from a single tertiary center. All patients underwent a multiparametric 1.5-T CMR protocol including biventricular strain, T 1 /T 2 mapping, and late gadolinium enhancement (LGE). Endomyocardial biopsy was chosen for the reference standard diagnosis. Among 452 consecutive patients, 103 (median age: 50 years; 66 men) had evaluable CMR and cardiopathologic reference diagnosis: 53 (51%) with chronic lymphocytic myocarditis and 50 (49%) with healed myocarditis. T 2 mapping as a single parameter showed the best accuracy in detecting chronic myocarditis, if abnormal in ≥3 segments (92%; 95% CI: 85-97), and provided the best discrimination from healed myocarditis, as defined by the area under the receiver-operating characteristic curve (0.87 [95% CI: 0.79-0.93]; P < 0.001), followed by radial peak systolic strain rate of the left ventricle (0.86) and the right ventricle (0.84); T 1 mapping (0.64), extracellular volume fraction (0.62), and LGE (0.57). Specificity increased when T 2 mapping was combined with elevation of either troponin or C-reactive protein. A multiparametric CMR protocol allows detection of ongoing myocardial inflammation and discrimination of chronic myocarditis from healed myocarditis, with segmental T 2 mapping and biventricular strain analysis showing higher diagnostic accuracy compared with T 1 mapping, extracellular volume fraction, and LGE. The use of biomarkers (troponin or C-reactive protein) may improve specificity. [Display omitted] [ABSTRACT FROM AUTHOR]

Aims To evaluate different cardiovascular magnetic resonance (CMR) parameters for the differentiation of light chain amyloidosis (AL) and transthyretin-related amyloidosis (ATTR). Methods and results In total, 75 patients, 53 with cardiac amyloidosis {20 patients with AL [66 ± 12 years, 14 males (70%)] and 33 patients with ATTR [78 ± 5 years, 28 males (88%)]} were retrospectively analysed regarding CMR parameters such as T1 and T2 mapping, extracellular volume (ECV), late gadolinium enhancement (LGE) distribution patterns, and myocardial strain, and compared to a control cohort with other causes of left ventricular hypertrophy {LVH; 22 patients [53 ± 16 years, 17 males (85%)]}. One-way ANOVA and receiver operating characteristic analysis were used for statistical analysis. ECV was the single best parameter to differentiate between cardiac amyloidosis and controls [area under the curve (AUC): 0.97, 95% confidence intervals (CI): 0.89–0.99, P < 0.0001, cut-off: >30%]. T2 mapping was the best single parameter to differentiate between AL and ATTR amyloidosis (AL: 63 ± 4 ms, ATTR: 58 ± 2 ms, P < 0.001, AUC: 0.86, 95% CI: 0.74–0.94, cut-off: >61 ms). Subendocardial LGE was predominantly observed in AL patients (10/20 [50%] vs. 5/33 [15%]; P = 0.002). Transmural LGE was predominantly observed in ATTR patients (23/33 [70%] vs. 2/20 [10%]; P < 0.001). The diagnostic performance of T2 mapping to differentiate between AL and ATTR amyloidosis was further increased with the inclusion of LGE patterns [AUC: 0.96, 95% CI: (0.86–0.99); P = 0.05]. Conclusion ECV differentiates cardiac amyloidosis from other causes of LVH. T2 mapping combined with LGE differentiates AL from ATTR amyloidosis with high accuracy on a patient level. [ABSTRACT FROM AUTHOR]

Introduction/Aims: T2 magnetic resonance imaging (MRI) mapping has been applied to carpal tunnel syndrome (CTS) for quantitative assessment of the median nerve. However, quantitative changes in the median nerve before and after surgery using T2 MRI mapping remain unclear. We aimed to investigate whether pathological changes could be identified by pre‐ and postoperative T2 MRI mapping of the median nerve in CTS patients after open carpal tunnel release. Methods: This was a prospective study that measured median nerve T2 and cross‐sectional area (CSA) values at the distal carpal tunnel, hamate bone, proximal carpal tunnel, and forearm levels pre‐ and postoperatively. Associations between T2, CSA, and nerve conduction latency were also evaluated. Results: A total of 36 patients with CTS (mean age, 64.5 ± 11.7 years) who underwent surgery were studied. The mean preoperative T2 values significantly decreased from 56.3 to 46.9 ms at the proximal carpal tunnel levels (p =.001), and from 52.4 to 48.7 ms at the hamate levels postoperatively (p =.04). Although there was a moderate association between preoperative T2 values at the distal carpal tunnel levels and distal motor latency values (r = −.46), other T2 values at all four carpal tunnel levels were not significantly associated with CSA or nerve conduction latency pre‐ or postoperatively. Discussion: T2 MRI mapping of the carpal tunnel suggested a decrease in nerve edema after surgery. T2 MRI mapping provides quantitative information on the median nerve before and after surgery. [ABSTRACT FROM AUTHOR]

Accurate prediction of renal mass subtypes, along with the WHO/ISUP grade and pathological T (pT) stage of clear cell renal cell carcinoma (ccRCC), is crucial for optimal decision making. Our study aimed to investigate the feasibility and reproducibility of motion-robust radial T2 mapping in differentiating lipid-poor angiomyolipoma (MFAML) from RCC and characterizing the WHO/ISUP grade and pT stage of ccRCC. Finally, 92 patients undergoing renal radial T2 mapping and ZOOMit DWI were recruited. The T2 values and apparent diffusion coefficient (ADC) were analyzed. Correlation coefficients were calculated between ADC and T2 values. Notably, ccRCC exhibited higher T2 and ADC values than MFAML (p < 0.05). T2 values were lower in the higher WHO/ISUP grade and pT stage of ccRCC (all p < 0.05). ADC showed no significant difference for pT stage (p = 0.056). T2 values revealed a higher area under the curve (AUC) in evaluating the WHO/ISUP grade compared to ADC (0.936 vs. 0.817, p = 0.027). T2 values moderately positively correlated with ADC (r = 0.675, p < 0.001). In conclusion, quantitative motion-robust radial T2 mapping is feasible for characterizing solid renal masses and could provide additional value for multiparametric imaging in predicting WHO/ISUP grade and pT stage of ccRCC. [ABSTRACT FROM AUTHOR]

Purpose: To develop a highly accelerated multi‐echo spin‐echo method, TEMPURA, for reducing the acquisition time and/or increasing spatial resolution for kidney T2 mapping. Methods: TEMPURA merges several adjacent echoes into one k‐space by either combining independent echoes or sharing one echo between k‐spaces. The combined k‐space is reconstructed based on compressed sensing theory. Reduced flip angles are used for the refocusing pulses, and the extended phase graph algorithm is used to correct the effects of indirect echoes. Two sequences were developed: a fast breath‐hold sequence; and a high‐resolution sequence. The performance was evaluated prospectively on a phantom, 16 healthy subjects, and two patients with different types of renal tumors. Results: The fast TEMPURA method reduced the acquisition time from 3–5 min to one breath‐hold (18 s). Phantom measurements showed that fast TEMPURA had a mean absolute percentage error (MAPE) of 8.2%, which was comparable to a standardized respiratory‐triggered sequence (7.4%), but much lower than a sequence accelerated by purely k‐t undersampling (21.8%). High‐resolution TEMPURA reduced the in‐plane voxel size from 3 × 3 to 1 × 1 mm2, resulting in improved visualization of the detailed anatomical structure. In vivo T2 measurements demonstrated good agreement (fast: MAPE = 1.3%–2.5%; high‐resolution: MAPE = 2.8%–3.3%) and high correlation coefficients (fast: R = 0.85–0.98; high‐resolution: 0.82–0.96) with the standardized method, outperforming k‐t undersampling alone (MAPE = 3.3–4.5%, R = 0.57–0.59). Conclusion: TEMPURA provides fast and high‐resolution renal T2 measurements. It has the potential to improve clinical throughput and delineate intratumoral heterogeneity and tissue habitats at unprecedented spatial resolution. [ABSTRACT FROM AUTHOR]

This review is focused on the current status of quantitative MRI (qMRI) of skeletal muscle. The first section covers the techniques of qMRI in muscle with the focus on each quantitative parameter, the corresponding imaging sequence, discussion of the relation of the measured parameter to underlying physiology/pathophysiology, the image processing and analysis approaches, and studies on normal subjects. We cover the more established parametric mapping from T1-weighted imaging for morphometrics including image segmentation, proton density fat fraction, T2 mapping, and diffusion tensor imaging to emerging qMRI features such as magnetization transfer including ultralow TE imaging for macromolecular fraction, and strain mapping. The second section is a summary of current clinical applications of qMRI of muscle; the intent is to demonstrate the utility of qMRI in different disease states of the muscle rather than a complete comprehensive survey. [ABSTRACT FROM AUTHOR]

Objective Cartilage and meniscus are important structures that maintain the health of the knee joint. Early detection of changes in the internal components of cartilage and meniscus before morphological changes occur is essential to prevent and delay the development of osteoarthritis (OA). This study was designed to determine the changes in the matrix composition of morphologically intact cartilage and meniscus during the acute phase of an anterior cruciate ligament (ACL) rupture, as well as the effect of different states of meniscus (intact or tear) on adjacent cartilage during the acute phase. Methods This cross‐sectional study compared and analyzed 50 patients in the acute phase of ACL rupture who underwent surgical treatment and 66 age‐, weight‐ and height‐matched healthy volunteers from May 2022 to May 2023 at our institution. Mean T2 relaxation times and effect sizes in different regions of tibiofemoral articular cartilage and meniscus were compared between the two groups using the Mann–Whitney nonparametric t‐test, and correlations between different meniscal states and adjacent cartilage were analyzed. Results Both in the lateral and medial compartments of the knee, T2 relaxation times were significantly higher in all subregions of cartilage and meniscus in the ACL rupture group (p

This review is focused on the current status of quantitative MRI (qMRI) of skeletal muscle. The first section covers the techniques of qMRI in muscle with the focus on each quantitative parameter, the corresponding imaging sequence, discussion of the relation of the measured parameter to underlying physiology/pathophysiology, the image processing and analysis approaches, and studies on normal subjects. We cover the more established parametric mapping from T1-weighted imaging for morphometrics including image segmentation, proton density fat fraction, T2 mapping, and diffusion tensor imaging to emerging qMRI features such as magnetization transfer including ultralow TE imaging for macromolecular fraction, and strain mapping. The second section is a summary of current clinical applications of qMRI of muscle; the intent is to demonstrate the utility of qMRI in different disease states of the muscle rather than a complete comprehensive survey.

Purpose: Echo modulation curve (EMC) modeling enables accurate quantification of T2 relaxation times in multi‐echo spin‐echo (MESE) imaging. The standard EMC‐T2 mapping framework, however, requires sufficient echoes and cumbersome pixel‐wise dictionary‐matching steps. This work proposes a deep learning version of EMC‐T2 mapping, called DeepEMC‐T2mapping, to efficiently estimate accurate T2 maps from fewer echoes. Methods: DeepEMC‐T2 mapping was developed using a modified U‐Net to estimate both T2 and proton density (PD) maps directly from MESE images. The network implements several new features to improve the accuracy of T2/PD estimation. A total of 67 MESE datasets acquired in axial orientation were used for network training and evaluation. An additional 57 datasets acquired in coronal orientation with different scan parameters were used to evaluate the generalizability of the framework. The performance of DeepEMC‐T2 mapping was evaluated in seven experiments. Results: Compared to the reference, DeepEMC‐T2 mapping achieved T2 estimation errors from 1% to 11% and PD estimation errors from 0.4% to 1.5% with ten/seven/five/three echoes, which are more accurate than standard EMC‐T2 mapping. By incorporating datasets acquired with different scan parameters and orientations for joint training, DeepEMC‐T2 exhibits robust generalizability across varying imaging protocols. Increasing the echo spacing and including longer echoes improve the accuracy of parameter estimation. The new features proposed in DeepEMC‐T2 mapping all enabled more accurate T2 estimation. Conclusions: DeepEMC‐T2 mapping enables simplified, efficient, and accurate T2 quantification directly from MESE images without dictionary matching. Accurate T2 estimation from fewer echoes allows for increased volumetric coverage and/or higher slice resolution without prolonging total scan times. [ABSTRACT FROM AUTHOR]

Abstract Background To explore and compare the values of 3.0T magnetic resonance imaging (MRI) T2 mapping in evaluating the degree of acetabular cartilage degeneration in hip replacement surgery. Methods A total of 26 elderly patients with femoral neck fractures who were scanned in 3.0T MRI T2 mapping quantification technique were included. Basing on MRI images, the degree of acetabular cartilage degeneration was classified into Grade 0, 1, 2, 3 and 4, according to the International Cartilage Repair Society (ICRS) scores. In addition, 8 healthy volunteers were included for control group. Results By comparison with health population, T2 relaxation values in the anterior, superior, and posterior regions of acetabular cartilage in patients with femoral neck fracture were obviously increased (P 0.05). Importantly, acetabular cartilage degeneration can be detected through signal changes of T2 mapping pseudo-color images. Conclusion 3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration, which can effectively monitor the disease course.

Cardiovascular magnetic resonance (CMR) imaging is widely regarded as the gold-standard technique for myocardial tissue characterization, allowing for the detection of structural abnormalities such as myocardial fatty replacement, myocardial edema, myocardial necrosis, and/or fibrosis. Historically, the identification of abnormal myocardial regions relied on variations in tissue signal intensity, often necessitating the use of exogenous contrast agents. However, over the past two decades, innovative parametric mapping techniques have emerged, enabling the direct quantitative assessment of tissue magnetic resonance (MR) properties on a voxel-by-voxel basis. These mapping techniques offer significant advantages by providing comprehensive and precise information that can be translated into color-coded maps, facilitating the identification of subtle or diffuse myocardial abnormalities. As unlikely conventional methods, these techniques do not require a substantial amount of structurally altered tissue to be visually identifiable as an area of abnormal signal intensity, eliminating the reliance on contrast agents. Moreover, these parametric mapping techniques, such as T1, T2, and T2* mapping, have transitioned from being primarily research tools to becoming valuable assets in the clinical diagnosis and risk stratification of various cardiac disorders. In this review, we aim to elucidate the underlying physical principles of CMR parametric mapping, explore its current clinical applications, address potential pitfalls, and outline future directions for research and development in this field. [ABSTRACT FROM AUTHOR]

Background: T2 mapping is a valuable technique in cardiac MR imaging that offers insights into the microstructural characteristics of myocardial tissue. However, it was shown that myocardial T2 relaxation times (T2) measured vary significantly depending on sequence, sequence parameters, and field strength. Purpose: To assess T2 variability and image quality in cardiac T2 maps using four variants of the gradient‐spin echo (GraSE) sequence, having different methods of blood signal suppression (double inversion recovery (DIR) and improved motion‐sensitized driven equilibrium (iMSDE) and with and without the addition of fat saturation (FS). Study Type: Prospective. Population: 48 healthy volunteers (46.7 +/− 21.5 years, 24 male) with no cardiac history. Field Strength/Sequence: GraSE sequence with DIR (GraSEDIR), with iMSDE (GraSEiMSDE) and FS (GraSEDIR‐FS) and with both iMSDE and FS (GraSEiMSDE‐FS) at 1.5T. Assessment: Global T2 from three short axis myocardial slices. and image quality assessments using a 5‐point Lickert scale (1, (non‐diagnostic) to 5, (excellent)) were conducted to evaluate the impact of DB and FS techniques on myocardial T2 measurements and image quality. Statistical Tests: Paired t‐tests or non‐parametric equivalents for comparisons between sequences. The Bland–Altmann plots and Pearson rank correlation analyses, as appropriate. A P value <0.05 was considered statistically significant. Results: The mean global T2 values for GraSEDIR, GraSEDIR‐FS, GraSEiMSDE, and GraSEiMSDE‐FS, were 52.84 ± 5.72 msec, 54.98 ± 3.59 msec, 53.9 ± 4.05 msec, and 55.14 ± 4.28 msec, respectively, with no significant differences (P = 0.092). High image quality scores (>4 out of 5) were obtained for all sequence variants with no significant differences between them (P = 0.11). Data Conclusion: All GraSE sequence variants exhibited approximately the same results and variations in the DB technique and addition of FS did not have significant impact on myocardial T2 values. Level of Evidence: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

Objective: Quantitative parameter mapping conventionally relies on curve fitting techniques to estimate parameters from magnetic resonance image series. This study compares conventional curve fitting techniques to methods using neural networks (NN) for measuring T2 in the prostate. Materials and methods: Large physics-based synthetic datasets simulating T2 mapping acquisitions were generated for training NNs and for quantitative performance comparisons. Four combinations of different NN architectures and training corpora were implemented and compared with four different curve fitting strategies. All methods were compared quantitatively using synthetic data with known ground truth, and further compared on in vivo test data, with and without noise augmentation, to evaluate feasibility and noise robustness. Results: In the evaluation on synthetic data, a convolutional neural network (CNN), trained in a supervised fashion using synthetic data generated from naturalistic images, showed the highest overall accuracy and precision amongst the methods. On in vivo data, this best performing method produced low-noise T2 maps and showed the least deterioration with increasing input noise levels. Discussion: This study showed that a CNN, trained with synthetic data in a supervised manner, may provide superior T2 estimation performance compared to conventional curve fitting, especially in low signal-to-noise regions. [ABSTRACT FROM AUTHOR]

Background: To explore and compare the values of 3.0T magnetic resonance imaging (MRI) T2 mapping in evaluating the degree of acetabular cartilage degeneration in hip replacement surgery. Methods: A total of 26 elderly patients with femoral neck fractures who were scanned in 3.0T MRI T2 mapping quantification technique were included. Basing on MRI images, the degree of acetabular cartilage degeneration was classified into Grade 0, 1, 2, 3 and 4, according to the International Cartilage Repair Society (ICRS) scores. In addition, 8 healthy volunteers were included for control group. Results: By comparison with health population, T2 relaxation values in the anterior, superior, and posterior regions of acetabular cartilage in patients with femoral neck fracture were obviously increased (P < 0.001). Among the patients with femoral neck fractures, there were 16 hip joint with Grade 1–2 (mild degeneration subgroup) and 10 hip joints with Grade 3–4 (severe degeneration subgroup), accounting for 61.54% and 38.46%, respectively. Additionally, T2 relaxation values in the anterior and superior bands of articular cartilage were positively related to the MRI-based grading (P < 0.05); while there was no significant difference of T2 relaxation values in the posterior areas of articular cartilage between severe degeneration subgroup and mild degeneration subgroup (P > 0.05). Importantly, acetabular cartilage degeneration can be detected through signal changes of T2 mapping pseudo-color images. Conclusion: 3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration, which can effectively monitor the disease course. [ABSTRACT FROM AUTHOR]

To improve image quality in highly accelerated parameter mapping by incorporating a linear constraint that relates consecutive images. In multi-echo T 1 or T 2 mapping, scan time is often shortened by acquiring undersampled but complementary measures of k-space at each TE or TI. However, residual undersampling artifacts from the individual images can then degrade the quality of the final parameter maps. In this work, a new reconstruction method, dubbed Constrained Alternating Minimization for Parameter mapping (CAMP), is introduced. This method simultaneously extracts T 2 or T 1 * maps in addition to an image for each TE or TI from accelerated datasets, leveraging the constraints of the decay to improve the reconstructed image quality. The model enforces exponential decay through a linear constraint, resulting in a biconvex objective function that lends itself to alternating minimization. The method was tested in four in vivo volunteer experiments and validated in phantom studies and healthy subjects, using T 2 and T 1 mapping, with accelerations of up to 12. CAMP is demonstrated for accelerated radial and Cartesian acquisitions in T 2 and T 1 mapping. The method is even applied to generate an entire T 2 weighted image series from a single TSE dataset, despite the blockwise k-space sampling at each echo time. Experimental undersampled phantom and in vivo results processed with CAMP exhibit reduced artifacts without introducing bias. For a wide array of applications, CAMP linearizes the model cost function without sacrificing model accuracy so that the well-conditioned and highly efficient reconstruction algorithm improves the image quality of accelerated parameter maps. [ABSTRACT FROM AUTHOR]

Background: Discriminating the stage of Graves' ophthalmopathy (GO) is crucial for clinical decision. Application of conventional T2-weighted imaging in the staging is still limited. Purpose: To evaluate the performance of T2 mapping based on two different regions of interest (ROIs) for staging GO. Material and Methods: In total, 56 GO patients were retrospectively enrolled and divided into two groups according to the clinical activity score (CAS). T2 relaxation time (T2RT) of extraocular muscle (EOM) on T2 mapping based on two different ROIs (T2RTROI-1: ROIs were drawn separately in the four EOMs; T2RTROI-2: ROI was drawn in the most inflamed EOM) was measured and compared between active and inactive groups. Results: Both T2RTROI-1 and T2RTROI-2 values in the active GO were significantly higher than those of inactive GO (P <0.001). T2RTROI-1 and T2RTROI-2 values were positively correlated with CAS (rs=0.73, 0.69; P <0.001). When the T2RTROI-1 value of 83.3 ms and T2RTROI-2 value of 106.3 ms were used as cutoff values for staging GO, respectively, the best results were obtained with areas under the curve (AUCs) of 0.822 and 0.827. There was no significant difference for AUCs between T2RTROI-1 and T2RTROI-2 (P = 0.751). Excellent and good inter-observer agreements were achieved in quantitative measurements for T2RTROI-1 and T2RTROI-2 values, respectively, with intraclass correlation coefficients of 0.954 and 0.882. Conclusion: The T2RT values derived from two different ROIs were useful for assessment of disease activity. Taking reproducibility and diagnostic performance into consideration, T2RTROI-1 would be an ideal image biomarker for staging GO compared to T2RTROI-2. [ABSTRACT FROM AUTHOR]

Background and Objectives: Over the past decade, there has been increasing attention paid to advanced and innovative cardiovascular magnetic resonance (CMR) modalities, such as T1 and T2 mapping, which play a major role in diagnosing diffuse myocardial disease. There is little data summarizing the current evidence regarding the diagnostic accuracy of T1 and T2 mapping, and extracellular volume (ECV) in acute myocarditis. The aim of our study was to select, analyze, and systematically review the recent scientific literature on the diagnostic value of CMR T1 and T2 parametric mapping in clinically suspected acute myocarditis. Materials and Methods: The literature search was performed in the PubMed database. Articles published in the years 2014–2024 were included in the analysis. At the initial stage, 458 articles were reviewed, and 13 exploratory research studies were further analyzed and presented in this systematic literature review. Results: The analysis included 686 patients with clinically suspected myocarditis and 372 subjects in the control group. The average age of patients with suspected myocarditis was 40.25 years; 26% of them were women. Prolonged native myocardial T1 relaxation time provides diagnostic accuracy in the setting of suspected acute myocarditis ranging from 69 to 99%, with sensitivity from 64 to 98% and specificity from 87 to 100%. Diagnostic accuracy of prolonged T2 relaxation time ranges from 47 to 87%, with sensitivity being from 48% to 94% and specificity from 60% to 92%. ECV alone showed moderate diagnostic performance, with diagnostic accuracy ranging from 62% to 76%, sensitivity from 47% to 73%, and specificity from 76% to 90%. T1 and T2 mapping and ECV, combined with the late gadolinium enhancement (LGE) technique, increases the probability of detecting myocardial inflammatory changes at various stages of the disease, improving the diagnostic accuracy to 96%. Conclusions: New quantitative CMR techniques, i.e., T1 and T2 mapping, have an advantage over conventional CMR sequences in detecting inflammatory myocardial structural changes and play an important role in diagnosing acute myocarditis. Incorporating these sequences in daily clinical practice increases the diagnostic value of CMR in acute myocarditis and becomes an alternative to endomyocardial biopsy, which has been considered the gold standard until now. [ABSTRACT FROM AUTHOR]

Background: Patients treated for symptomatic rotator cuff tear (RCT) on one shoulder seem to have a higher prevalence of RCT on the contralateral shoulder. Purpose: To compare the supraspinatus (SSP) tendon and RC muscle properties on the contralateral shoulder in patients after repair surgery to those healthy individuals using quantitative magnetic resonance imaging (MRI). Material and Methods: A total of 23 patients treated for RCT (group A) and 23 healthy controls (group B) were recruited. Constant score, visual analog scale score (VAS), and MRI examinations were conducted. The SSP tendon structural status was graded based on the Zlatkin classification and quantified on ultrashort echo time (UTE)-T2* mapping images. Fatty degeneration of RC muscles was classified according to the Goutallier classification and quantified on T2 mapping. Results: The Constant and VAS scores were comparable between groups A and B (all P >0.05). No significant differences were observed in tendon structural status between the two groups (P >0.05). However, significant differences were established in UTE-T2* values of the SSP tendon on the distal subregion between groups A and B (16.4 ± 2.4 ms vs. 14.8 ± 1.2 ms; P = 0.01). Regarding muscle degeneration, no significant differences were displayed in T2 values and Goutallier classification of RC muscles (all P >0.05). Conclusion: Patients with a treated RCT demonstrated inferior SSP tendon in the distal subregion on the contralateral shoulders one year postoperatively compared to that of healthy controls based on quantitative MRI data. [ABSTRACT FROM AUTHOR]

Purpose: The increasing incidence of kidney diseases is a global concern, and current biomarkers and treatments are inadequate. Changes in renal tubule luminal volume fraction (TVF) serve as a rapid biomarker for kidney disease and improve understanding of renal (patho)physiology. This study uses the amplitude of the long T2 component as a surrogate for TVF in rats, by applying multiexponential analysis of the T2-driven signal decay to examine micromorphological changes in renal tissue. Methods: Simulations were conducted to identify a low mean absolute error (MAE) protocol and an accelerated protocol customized for the in vivo study of T2 mapping of the rat kidney at 9.4 T. We then validated our bi-exponential approach in a phantom mimicking the relaxation properties of renal tissue. This was followed by a proof-of-principle demonstration using in vivo data obtained during a transient increase of renal pelvis and tubular pressure. Results: Using the low MAE protocol, our approach achieved an accuracy of MAE<1% on the mechanical phantom. The T2 mapping protocol customized for in vivo study achieved an accuracy of MAE <3%. Transiently increasing pressure in the renal pelvis and tubules led to significant changes in TVF in renal compartments: ΔTVFcortex =4.9%, ΔTVFouter_medulla =4.5%, and ΔTVFinner_medulla =-14.6%. Conclusion: These results demonstrate that our approach is promising for research into quantitative assessment of renal TVF in in vivo applications. Ultimately, these investigations have the potential to help reveal mechanism in acute renal injury thatmay lead to chronic kidney disease, which will support research into renal disorders. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chondromalacia is a common pathology of joints, leading to a decrease in the patient's quality of life. Magnetic resonance imaging is the method of choice for the diagnosis of articular cartilage defects [1]. T2 mapping of cartilage is a non-invasive quantitative technique that allows estimation of its T2-relaxation time, which may be relevant in cases where articular cartilage surveillance is recommended [2–5]. AIM: To study the magnetic resonance characteristics of knee cartilage using a routine protocol and T2 mapping technique in patients at risk of chondromalacia. MATERIALS AND METHODS: Magnetic resonance research of the knee joint was prospectively performed on 35 patients aged 18–70 years who signed informed voluntary consent in the period from 2022 to 2023. The study was approved by the local ethical committee of International Tomography Center (Novosibirsk, Russia). Exclusion criteria: exacerbation stage of comorbid diseases, knee joint osteoarthritis of stages 3–4. The main group consisted of patients with signs of chondromalacia; the group with initial degenerative changes — of patients with local areas of thinning and/or changes in the signaling characteristics of articular cartilage with minor/no degenerative changes of the joint. The control group consisted of patients without changes in cartilage signaling characteristics, traumatic and degenerative changes of the knee joint. The study of the knee joint was performed on a Philips INGENIA magnetic resonance tomograph (1.5T intensity) using the routine protocol: T2-weighted images, PD-SPAIR, PD-weighted images, T1-weighted images and T2 mapping technique with calculation of the T2-relaxation time of the cartilage tissue. Statistical analysis was performed using non-parametric research methods (Mann–Whitney U-test, Spearman correlation coefficient). The critical level of significance (p) is 0.05. RESULTS: The median age in the control group was 28.0 [24.0; 38.0] years, in the main group 48.0 [37.2; 55.7] years, and in the group with initial degenerative changes 48.0 [38.2; 59.5] years. Analysis of the localization of the cartilage defect of the knee joint revealed that chondromalacia was determined on the medial facet of the patella in 11 (91.6%) patients, on the lateral facet of the patella in 4 (33.3%) patients, and on the medial femoral condyle in 4 (33.3%) patients. When measuring cartilage thickness, a high individual variability of values was revealed with its significant decrease only in the defect area (p 0.05), with no significant differences between the groups in the other sections (p 0.05). When evaluating the values of cartilage T2-relaxation time, its statistically significant increase was revealed in the area of patella cartilage in patients from the main group and with initial degenerative changes (p 0.001 and p 0.01), cartilage of medial femoral condyle in patients with initial degenerative changes (p 0.05) in comparison with the control group. Correlation analysis between cartilage thickness and T2-relaxation time was performed, significant pairs were found: in the control group — in the area of lateral femoral condyle (p=0.011, r=0.636), in the main group — on the medial facet of the patella (r=–0.591, p=0.043), and in the area of medial femoral condyle (r=–0.760, p=0.004). In other cases, no significant correlations between cartilage thickness and patient groups were found. CONCLUSION: A statistically significant local increase in the T2-relaxation time in the patient groups revealed in comparison with the control group at high variability of cartilage thickness. The presented results indicate that the predominant diagnostic criterion is the change in signaling characteristics and increase in T2-relaxation time in the cartilage structure.

Abstract Background Characterisation of the structure and water status of leaf tissues is essential to the understanding of leaf hydraulic functioning under optimal and stressed conditions. Magnetic Resonance Imaging is unique in its capacity to access this information in a spatially resolved, non-invasive and non-destructive way. The purpose of this study was to develop an original approach based on transverse relaxation mapping by Magnetic Resonance Imaging for the detection of changes in water status and distribution at cell and tissue levels in Brassica napus leaves during blade development and dehydration. Results By combining transverse relaxation maps with a classification scheme, we were able to distinguish specific zones of areoles and veins. The tissue heterogeneity observed in young leaves still occurred in mature and senescent leaves, but with different distributions of T2 values in accordance with the basipetal progression of leaf blade development, revealing changes in tissue structure. When subjected to severe water stress, all blade zones showed similar behaviours. Conclusion This study demonstrates the great potential of Magnetic Resonance Imaging in assessing information on the structure and water status of leaves. The feasibility of in planta leaf measurements was demonstrated, opening up many opportunities for the investigation of leaf structure and hydraulic functioning during development and/or in response to abiotic stresses.

Abstract Background Ankle joint cartilage injury is frequently associated with degenerative changes, even in the absence of symptoms. Earlier treatment of cartilage damage with joint preservation is clearly more successful. The main limitation of morphologic cartilage magnetic resonance imaging sequences is that they are not very sensitivity in the detection of early cartilage degeneration. Recent advances in biochemical magnetic resonance imaging have yielded sequences that are sensitive to molecular changes in the composition of cartilage matrix. This includes water- and collagen-sensitive T2\T2* mapping. The aim of this study was to determine the extent of improvement of the diagnostic performance of routine magnetic resonance imaging protocol in the evaluation of ankle joint articular cartilage lesions following the addition of a T2 mapping sequence. Results A total of 45 cases, 30 patients (12 male and 18 female) and 15 controls (10 male and 5 female) who underwent routine ankle magnetic resonance imaging with additional T2 mapping sequence, were included in the study. Out of 30 patients, four patients were misdiagnosed as being normal, while having changes of cartilage composition of early degenerative changes, discovered by T2 mapping sequence. The patients group as well as the-control groups had significantly higher T2-values in the superficial cartilage layer (P

PurposeTo develop a deep learning-based method to retrospectively quantify T2 from conventional T1- and T2-weighted images.MethodsTwenty-five subjects were imaged using a multi-echo spin-echo sequence to estimate reference prostate T2 maps. Conventional T1- and T2-weighted images were acquired as the input images. A U-Net based neural network was developed to directly estimate T2 maps from the weighted images using a four-fold cross-validation training strategy. The structural similarity index (SSIM), peak signal-to-noise ratio (PSNR), mean percentage error (MPE), and Pearson correlation coefficient were calculated to evaluate the quality of network-estimated T2 maps. To explore the potential of this approach in clinical practice, a retrospective T2 quantification was performed on a high-risk prostate cancer cohort (Group 1) and a low-risk active surveillance cohort (Group 2). Tumor and non-tumor T2 values were evaluated by an experienced radiologist based on region of interest (ROI) analysis.ResultsThe T2 maps generated by the trained network were consistent with the corresponding reference. Prostate tissue structures and contrast were well preserved, with a PSNR of 26.41 ± 1.17 dB, an SSIM of 0.85 ± 0.02, and a Pearson correlation coefficient of 0.86. Quantitative ROI analyses performed on 38 prostate cancer patients revealed estimated T2 values of 80.4 ± 14.4 ms and 106.8 ± 16.3 ms for tumor and non-tumor regions, respectively. ROI measurements showed a significant difference between tumor and non-tumor regions of the estimated T2 maps (P

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy divided into two types: light-chain (LA) and transthyretin (ATTR) CA. Cardiac magnetic resonance (CMR) has emerged as an important diagnostic tool in CA. While late gadolinium enhancement (LGE), T1 mapping and extracellular volume (ECV) have a consolidate role in the assessment of CA, T2 mapping has been less often evaluated. We aimed to test the value of T2 mapping in the evaluation of CA. This study recruited 70 patients with CA (51 ATTR, 19 AL). All the subjects underwent 1.5 T CMR with T1 and T2 mapping and cine and LGE imaging. Their QALE scores were evaluated. The myocardial T2 values were significantly (p < 0.001) increased in both types of CA compared to the controls. In the AL-CA group, increased T2 values were associated with a higher QALE score. The myocardial native T1 values and ECV were significantly (p < 0.001) higher in the CA patients than in the healthy subjects. Left ventricular (LV) mass, QALE score and ECV were higher in ATTR amyloidosis compared with AL amyloidosis, while the LV ejection fraction was lower (p < 0.001). These results support the concept of the presence of myocardial edema in CA. Therefore, a CMR evaluation including not only myocardial T1 imaging but also myocardial T2 imaging allows for more comprehensive tissue characterization in CA. [ABSTRACT FROM AUTHOR]

Background: Characterisation of the structure and water status of leaf tissues is essential to the understanding of leaf hydraulic functioning under optimal and stressed conditions. Magnetic Resonance Imaging is unique in its capacity to access this information in a spatially resolved, non-invasive and non-destructive way. The purpose of this study was to develop an original approach based on transverse relaxation mapping by Magnetic Resonance Imaging for the detection of changes in water status and distribution at cell and tissue levels in Brassica napus leaves during blade development and dehydration. Results: By combining transverse relaxation maps with a classification scheme, we were able to distinguish specific zones of areoles and veins. The tissue heterogeneity observed in young leaves still occurred in mature and senescent leaves, but with different distributions of T2 values in accordance with the basipetal progression of leaf blade development, revealing changes in tissue structure. When subjected to severe water stress, all blade zones showed similar behaviours. Conclusion: This study demonstrates the great potential of Magnetic Resonance Imaging in assessing information on the structure and water status of leaves. The feasibility of in planta leaf measurements was demonstrated, opening up many opportunities for the investigation of leaf structure and hydraulic functioning during development and/or in response to abiotic stresses. [ABSTRACT FROM AUTHOR]

Early diagnosis of patients with dilated cardiomyopathy (DCM) remains challenging. Cardiac MR can correlate myocardial changes with their pathological basis. There have been some previous studies on the effect of T1 mapping in DCM, but there is limited data on the incremental value of T2 mapping for DCM in routine clinical practice. This study will examine whether the combination of MRI T1 and T2 mapping offers greater advantages in the diagnosis of DCM. The study included 28 patients with DCM and 21 healthy controls. CMR evaluation included late gadolinium enhancement (LGE), T1 mapping, extracellular volume (ECV) fraction and T2 mapping. The DCM group was divided into LGE (+) and LGE (−) subgroups. The main modes of LGE are subendocardial, midwall, subepicardial, or transmural. T1 values, T2 values, and ECV in the 16 segments myocardial levels were measured by post-processing software. Student's t-tests or Mann–Whitney U test was used to compare between two groups, and one-way ANOVA or Kruskal–Wallis H test was used to compare between multiple groups, with p values corrected by Bonferroni. The difference was considered statistically significant at P < 0.05. ROC curve analysis was used to compare the area under the curve (AUC) of each index and its combined value, and the cut-off value, sensitivity and specificity were determined by Jordan's index. Mean native myocardial T1, ECV and T2 were significantly higher in the DCM group compared to controls (p ≤ 0.001, respectively). The best cut-off values for T1, T2 and ECV to discriminate DCM from controls were 1184 ms, 40.9 ms and 29.2%, respectively. The AUC of T1, ECV and T2 were 0.87, 0.89, and 0.83, respectively. The combined AUC of the three values was 0.96. Native T1 value and ECV overcome some of the limitations of LGE, and the T2 helps to understand the extent of myocardial damage. The combination of T1 and T2 mapping techniques can reveal fibrotic and oedematous changes in the early stages of DCM, providing a more comprehensive assessment of DCM and better guidance for individualised clinical management of patients. We suggest that the addition of T2 mapping to the routine CMR examination of patients with suspected DCM, and the combined assessment of T1mapping and T2 mapping can provide complementary information about the disease and improve the early diagnosis of DCM. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether a T2 inter‐slice variation could occur when a multi‐slice multi‐echo spin echo (MESE) sequence is used for image acquisition and to propose an enhanced method for reconstructing T2 maps that can effectively address and correct these variations. Methods: Bloch simulations were performed accounting for the direct saturation effect to evaluate magnetization changes in multi‐slice 2D MESE sequence. Experimental phantom scans were performed to validate these simulations. An improved version of the dictionary‐based reconstruction approach was proposed, enabling the creation of a multi‐slice dictionary of echo modulation curves (EMC). The corresponding method has been assayed considering inter‐slice T2 variation with phantoms and in lower leg. Results: Experimental and numerical study illustrate that direct saturation leads to a bias of EMCs. This bias during the T2 maps reconstructions using original single‐slice EMC‐dictionary method led to inter‐slice T2 variation of 2.03% in average coefficient of variation (CV) in agarose phantoms, and up to 2.8% in vivo (for TR = 2 s, slice gap = 0%). A reduction of CV was observed when increasing the gap up to 100% (0.36% in phantoms, and up to 1.5% in vivo) or increasing TR up to 4 s (0.76% in phantoms, and up to 1.9% in vivo). Matching the multi‐slice experimental data with multi‐slice dictionaries provided a reduced CV of 0.54% in phantoms and up to 2.3% in vivo. Conclusion: T2 values quantified from multi‐slice MESE images using single‐slice dictionaries are biased. A dedicated multi‐slice EMC method providing the appropriate dictionaries can reduce the inter‐slice T2 variation. [ABSTRACT FROM AUTHOR]

Purpose: To develop a deep image prior (DIP) reconstruction for B1+‐corrected 2D cine MR fingerprinting (MRF). Methods: The proposed method combines low‐rank (LR) modeling with a DIP to generate cardiac phase‐resolved parameter maps without motion correction, employing self‐supervised training to enforce consistency with undersampled spiral k‐space data. Two implementations were tested: one approach (DIP) for cine T1, T2, and M0 mapping, and a second approach (DIP with effective B1+ estimation [DIP‐B1]) that also generated an effective B1+ map to correct for errors due to RF transmit inhomogeneities, through‐plane motion, and blood flow. Cine MRF data were acquired in 14 healthy subjects and four reconstructions were compared: LR, low‐rank motion‐corrected (LRMC), DIP, and DIP‐B1. Results were compared to diastolic ECG‐triggered MRF, MOLLI, and T2‐prep bSSFP. Additionally, bright‐blood and dark‐blood images calculated from cine MRF maps were used to quantify ventricular function and compared to reference cine measurements. Results: DIP and DIP‐B1 outperformed other cine MRF reconstructions with improved noise suppression and delineation of high‐resolution details. Within‐segment variability in the myocardium (reported as the coefficient of variation for T1/T2) was lowest for DIP‐B1 (2.3/8.3%) followed by DIP (2.7/8.7%), LRMC (3.5/10.5%), and LR (15.3/39.6%). Spatial homogeneity improved with DIP‐B1 having the lowest intersegment variability (2.6/4.1%). The mean bias in ejection fraction was −1.1% compared to reference cine scans. Conclusion: A DIP reconstruction for 2D cine MRF enabled cardiac phase‐resolved mapping of T1, T2, M0, and the effective B1+ with improved noise suppression and precision compared to LR and LRMC. [ABSTRACT FROM AUTHOR]

Intraductal T2 mapping based on a catheter receiver is proposed as a method of visualizing the extent of intraductal and periductal cholangiocarcinoma (CCA). Compared to external receivers, internal receivers provide locally enhanced signal-to-noise ratios by virtue of their lower field-of-view for body noise, allowing smaller voxels and higher resolution. However, inherent radial sensitivity variation and segmentation for patient safety both distort image brightness. We discuss simulated T2 weighted images and T2 maps, and in vitro images obtained using a thin film catheter receiver of a freshly resected liver specimen containing a polypoid intraductal tumor from a patient with CCA. T2 mapping provides a simple method of compensating non-uniform signal reception patterns of catheter receivers, allowing the visualization of tumor extent without contrast enhancement and potentially quantitative tissue characterization. Potential advantages and disadvantages of in vivo intraductal imaging are considered. [ABSTRACT FROM AUTHOR]

Background: Diagnosing knee osteoarthritis (KOA) often relies on limited routine methods. This study investigates the efficacy of T2 mapping and Apparent Diffusion Coefficient (ADC) values in MRI for enhanced assessment of cartilage damage in KOA, focusing on their correlation with pain severity. Materials and Methods: A total of 52 KOA patients (74 knee joints) and 50 healthy individuals (100 knee joints) were assessed from May 2022 to June 2023. Both groups underwent MRI with Diffusion Weighted Imaging (DWI) sequence and T2 mapping to analyze ADC and T2 mapping values across femoral condyle, tibial plateau, and patellar joint surfaces, and their correlation with pain levels. Results: The KOA group showed significantly higher ADC and T2 mapping values in all examined areas compared to the control group (P<0.05). These values were also higher in advanced stages of cartilage degeneration and correlated positively with increased pain scores (P<0.05). Conclusion: MRI utilizing DWI and T2 mapping provides a quantitative reflection of knee joint cartilage degeneration in KOA. These methods show a positive correlation with pain severity, suggesting their potential for more accurate KOA diagnostics and assessment. [ABSTRACT FROM AUTHOR]

Amyloidosis is a rare infiltrative condition resulting from the extracellular accumulation of amyloid fibrils at the cardiac level. It can be an acquired condition or due to genetic mutations. With the progression of imaging technologies, a non-invasive diagnosis was proposed. In this study, we discuss the role of CMR in cardiac amyloidosis, focusing on the two most common subtypes (AL and ATTR), waiting for evidence-based guidelines to be published. [ABSTRACT FROM AUTHOR]

T 2 mapping of short-T 2 tissues in the knee (meniscus, tendon, and ligament) is needed to aid the clinical MRI knee diagnosis, which is hard to realize using traditional clinical methods. To accelerate the acquisition of T 2 values for short-T 2 tissues in the knee by analyzing the signal equation of balanced steady-state free precession (bSSFP) sequence in MRI. Effect of half-radial acquisition on pixel bandwidth was analyzed mathematically. A modified 3D radial dual-echo bSSFP sequence was proposed for 0.53 mm isotropic resolution knee imaging with 2 different TEs at 3 T, which alleviated the problem of off-resonance artifacts caused by traditional half-radial acquisition scheme. A novel pixel-based optimization method was proposed for efficient T 2 mapping of short-T 2 tissues in the knee given off-resonance values. Simulation was conducted to evaluate the sensitivity of the proposed method to other parameters. Phantom results were compared with 2D spin-echo (SE), and in vivo results were compared with SE and previously studies. Simulation showed that the proposed method is insensitive to T 1 and B 1 variations (estimation error < 1% for T 1 /B 1 error of ±90%), avoiding the need for separated T 1 and B 1 scans. High isotropic resolution knee imaging was achieved using the modified dual-echo bSSFP. The total scan time was within 3.5 min, including a separate off-resonance scan for T 2 measurement. Measured mean T 2 values for phantoms correlated well with SE (R2 = 0.99), and no significant difference was observed (P = 0.45). In vivo meniscus T 2 measurements and ligament T 2 measurements agreed with the literature, while tendon T 2 measurements were much lower (31.7% lower for patellar tendon, and 13.5% lower for quadriceps tendon), which might result in its bi-component property. The proposed method provides an efficient way for fast, robust, high-resolution imaging and T 2 mapping of short-T 2 tissues in the knee. [ABSTRACT FROM AUTHOR]

Background: Previous studies have examined patients with chronic lateral ankle instability (CLAI) undergoing open and arthroscopic anterior talofibular ligament (ATFL) reconstruction, reporting equivalent clinical results between the 2 procedures. However, data on the magnetic resonance imaging (MRI) outcomes on cartilage health after the 2 procedures are limited. Purpose: To compare the cartilage MRI T2 values of the talar and subtalar joints between patients with CLAI undergoing open and arthroscopic ATFL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: A prospective study was conducted on patients who underwent open or arthroscopic ATFL reconstruction between January 2018 and December 2019, with a mean follow-up duration of 3 years. MRI scans and American Orthopaedic Foot & Ankle Society (AOFAS) and Tegner score estimations were completed by patients ≤1 week before surgery, as a baseline measurement, and at a 3-year follow-up. A total of 21 healthy volunteers were included who underwent MRI at baseline. Cartilage health was evaluated using MRI T2 mapping. The talar and subtalar cartilage regions were segmented into 14 subregions. Results: At baseline, patients with CLAI had substantially higher T2 values in the medial anterior, medial center, medial posterior, and lateral center regions on the talus compared with the healthy controls (P =.009,.003,.001, and.025, respectively). Remarkable increases in T2 values in the lateral posterior region on the talus were observed from baseline to follow-up in the open group (P =.007). Furthermore, T2 values were considerably higher in the medial center, medial posterior, lateral posterior, and lateral posterior calcaneal facets of the posterior subtalar joint at follow-up in the arthroscopic group compared with the baseline values (P =.025,.002,.006, and.044, respectively). No obvious differences in ΔT2 values were noted between the 2 groups at follow-up. The AOFAS and Tegner scores remarkably improved from baseline to follow-up for the 2 groups (open: 3.25 ± 0.58 vs 5.13 ± 0.81, P <.001; arthroscopic: 3.11 ± 0.90 vs 5.11 ± 1.08, P <.001), with no considerable difference between them. Conclusion: The elevated T2 values of cartilage could not be fully recovered after open or arthroscopic ATFL reconstruction. Both arthroscopic and open ATFL reconstruction displayed similar effects on cartilage health concerning ΔT2, but the arthroscopic group demonstrated more degenerative cartilage subregions than the open group. [ABSTRACT FROM AUTHOR]

Background: In most cases, lateral patellar dislocation (LPD) is accompanied by chondral injury and may initiate gradual degeneration of patellar cartilage, which might be detected with a T2 mapping, a well‐established method for cartilage lesions assessment. Purpose: To examine short‐term consequences of single first‐time LPD in teenagers by T2 mapping of the patellar‐cartilage state. Study Type: Prospective. Population: 95 patients (mean age: 15.1 ± 2.3; male/female: 46/49) with first‐time, complete, traumatic LPD and 51 healthy controls (mean age: 14.7 ± 2.2, male/female: 29/22). Field Strength/Sequence: 3.0 T; axial T2 mapping acquired using a 2D turbo spin‐echo sequence. Assessment: MRI examination was conducted 2–4 months after first LPD. T2 values were calculated in manually segmented cartilage area via averaging over three middle level slices in six cartilage regions: deep, intermediate, superficial layers, and medial lateral parts. Statistical Tests: ANOVA analysis with Tukey's multiple comparison test, one‐vs.‐rest logistic regression analysis. The threshold of significance was set at P < 0.05. Results: In lateral patellar cartilage, a significant increase in T2 values was found in deep and intermediate layers in both patient groups with mild (deep: 34.7 vs. 31.3 msec, intermediate: 38.7 vs. 34.6 msec, effect size = 0.55) and severe (34.8 vs. 31.3 msec, 39.1 vs. 34.6 msec, 0.55) LPD consequences as compared to controls. In the medial facet, only severe cartilage damage showed significant prolongation of T2 times in the deep layer (34.3 vs. 30.7 msec, 0.55). No significant changes in T2 values were found in the lateral superficial layer (P = 0.99), whereas mild chondromalacia resulted in a significant decrease of T2 in the medial superficial layer (41.0 vs. 43.8 msec, 0.55). Data Conclusion: The study revealed substantial difference in T2 changes after LPD between medial and lateral areas of patellar cartilage. Evidence Level: 2 Technical Efficacy Stage: 2 [ABSTRACT FROM AUTHOR]

Background: Few studies assessed myocardial inflammation using Cardiovascular Magnetic Resonance Imaging in Kawasaki disease (KD) patients. Purpose: To quantify myocardial edema in KD patients using T2 mapping and explore the independent predictors of T2 values. Study Type: Prospective. Subjects: Ninety KD patients including 40 in acute phase (26 males, 65.0%) and 50 in chronic phase (34 males, 68.0%). Thirty‐one healthy volunteers (21 males, 70.0%). Field Strength/Sequence: 3.0 T T2‐weighted Turbo Spin Echo‐Short Time of Inversion Recovery sequence, True fast imaging with steady precession flash sequence and fast low‐angle shot 3D spoiled gradient echo sequence. Assessment: T2 values were compared among KD groups and controls. Statistical Test: Student's t test and Fisher's exact test; One‐way analysis of variance; Pearson correlation analysis; Receiver operating curve analysis; Multivariable linear regression. Results: Global T2 value of KD patients in acute phase was the highest, followed by those of chronic‐phase patients and controls (38.83 ± 2.41 msec vs. 37.55 ± 2.28 msec vs. 36.05 ± 1.64 msec). Regional T2 values showed a same trend. There were no significant differences in global and regional T2 values between KD patients with and without coronary artery (CA) dilation, no matter in acute or chronic phase (all KD patients: P = 0.51, 0.51, 0.53, 0.72; acute KD: P = 0.61, 0.37, 0.33, 0.83; chronic KD: P = 0.65, 0.79, 0.62, 0.79). No significant difference was observed in global T2 values between KD patients with Z score > 5.0 and 2.0 < Z score ≤ 5.0 (P = 0.65). Multivariate analysis demonstrated that stage of disease (β = −0.123) and heart rate (β = 0.280) were independently associated with global T2 values. Data Conclusion: The degree of myocardial edema was more severe in acute‐phase than in chronic‐phase KD patients. Myocardial edema persists in patients regardless of the existence or degree of CA dilation. Evidence Level: 2 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

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Abstract Background Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in childhood that can lead to irreversible cartilage damage, with associated disability and decreased life quality. Shear wave elastography and quantitative MRI mapping can be used to identify early cartilage affection. Purpose To evaluate diagnostic utility of distal femoral cartilage shear wave elastography and MRI T2 mapping in patients with symptomatic knee and investigate their potential clinical significance. Material and methods Twenty patients with knee affection (study group) and 20 volunteers with the same demographic characteristics but without symptomatic knee pain (control group) were included in the study. A total of 80 knee joints of 40 individuals were evaluated. At the medial, intercondylar, and lateral condylar levels, distal femoral cartilage thickness was measured by B-mode ultrasonography and MRI, stiffness was assessed by shear wave elastography, and T2 relaxation time was measured by MRI. Results The medial, intercondylar, and lateral cartilage thickness measurements were similar between the two groups and no statistically significant difference was observed while measured by US (P value 0.653,0.702,0.607) and MRI (P value 0.414, 0.4187, 0.3903). The shear wave velocity values in the study group were significantly higher than in the control group (P value 0.0202). There was a statistically significant difference between the average T2 relaxation time values for the distal femoral cartilage in the study and the control groups (P value 0.0027). SWE results were statistically significant in moderate and high disease activity while T2* revealed statistically significant p values in low as well as moderate and high disease activity; we found the best cutoff values for detection of cases using shear wave elastography velocity ratio (m/sec) about 4.445 with significant p value = 0.02, sensitivity 59.3% and specificity = 70.45%. Conclusion Shear wave elastography and MRI T2 mapping are reliable, non-invasive, and acceptable methods for the assessment of pathologic cartilage. Better diagnostic information of hyaline cartilage can be obtained by adding up an extra sequence called T2 mapping to the routine MRI protocol of knee.

Abstract Background This study seeks to assess the utility of T1 and T2 mapping in distinguishing metastatic lymph nodes from reactive lymphadenopathy in patients with head and neck squamous cell carcinoma (HNSCC), using diffusion-weighted imaging (DWI) as a comparison. Methods Between July 2017 and November 2019, 46 HNSCC patients underwent neck MRI inclusive of T1 and T2 mapping and DWI. Quantitative measurements derived from preoperative T1 and T2 mapping and DWI of metastatic and non-metastatic lymph nodes were compared using independent samples t-test or Mann–Whitney U test. Receiver operating characteristic curves and the DeLong test were employed to determine the most effective diagnostic methodology. Results We examined a total of 122 lymph nodes, 45 (36.9%) of which were metastatic proven by pathology. Mean T2 values for metastatic lymph nodes were significantly lower than those for benign lymph nodes (p

Accurate prediction of renal mass subtypes, along with the WHO/ISUP grade and pathological T (pT) stage of clear cell renal cell carcinoma (ccRCC), is crucial for optimal decision making. Our study aimed to investigate the feasibility and reproducibility of motion-robust radial T2 mapping in differentiating lipid-poor angiomyolipoma (MFAML) from RCC and characterizing the WHO/ISUP grade and pT stage of ccRCC. Finally, 92 patients undergoing renal radial T2 mapping and ZOOMit DWI were recruited. The T2 values and apparent diffusion coefficient (ADC) were analyzed. Correlation coefficients were calculated between ADC and T2 values. Notably, ccRCC exhibited higher T2 and ADC values than MFAML (p < 0.05). T2 values were lower in the higher WHO/ISUP grade and pT stage of ccRCC (all p < 0.05). ADC showed no significant difference for pT stage (p = 0.056). T2 values revealed a higher area under the curve (AUC) in evaluating the WHO/ISUP grade compared to ADC (0.936 vs. 0.817, p = 0.027). T2 values moderately positively correlated with ADC (r = 0.675, p < 0.001). In conclusion, quantitative motion-robust radial T2 mapping is feasible for characterizing solid renal masses and could provide additional value for multiparametric imaging in predicting WHO/ISUP grade and pT stage of ccRCC.