T1ρ mapping is a new quantitative MRI technique in recent years. In order to use T1ρ mapping as a noncontrast method to assess myocardial fibrosis, it is necessary to establish a range of normal values.To establish a potential normal range of cardiac T1ρ values in healthy adults and to explore the influence of slice location and gender on T1ρ values.Prospective.A total of 57 healthy volunteers without cardiovascular risk factors (age 26.7 ± 11.8 years; 29 males).1.5 T; modified Look-Locker inversion recovery (MOLLI) (T1 mapping), multiecho gradient-spin-echo (GraSE) (T2 mapping) and T1ρ -prepared steady-state free precession (T1ρ mapping) sequences.Basal, mid, and apical short-axis left ventricular T1 , T2 , and T1ρ maps were acquired. T1ρ maps at spin-locking frequencies of 5 and 400 Hz were subtracted to create myocardial fibrosis index (mFI) maps. Slice-average and global average T1 , T2 , T1ρ , and mFI values were determined.Shapiro-Wilk test, Independent t-test, ANOVA test, Pearson correlation coefficient (r).P value < 0.05.The global average values of T1 , T2 , T1ρ, and mFI were 1053 ± 34 msec, 51.9 ± 2.3 msec, 47.9 ± 2.8 msec, and 4.4 ± 1.6 msec. T1ρ values showed a significant gradual increase from the basal slice to the apical slice of the heart (basal 46.5 ± 2.7 msec, mid 48.0 ± 2.9 msec, apical 49.2 ± 3.3 msec). The T1ρ and mFI values of females (49.7 ± 2.4 msec and 5.1 ± 1.2 msec, respectively) were significantly higher than those of males (46.2 ± 1.9 msec and 3.7 ± 1.7 msec, respectively). In addition, there was a moderate positive correlation between global T1ρ values and global T1 values (r = 0.44, P < 0.05) and a moderate positive correlation between global T1ρ values and global T2 values (r = 0.42, P < 0.05).In this study, the global T1ρ values of healthy adults' hearts were 47.9 ± 2.8 msec. This study found that gender and slice location of myocardium can affect the T1ρ values.4 TECHNICAL EFFICACY: Stage 1.
This retrospective study was to evaluate the feasibility and accuracy of coronary artery calcium score (CACS) from virtual non-contrast (VNC) images in comparison with that from true non-contrast (TNC) images. A total of 540 patients with suspected of coronary artery disease (CAD) who underwent a dual-layer spectral detector CT (SDCT) in three hospitals were eligible for this study and 233 patients were retrospectively enrolled for further analysis. The CACS was calculated from both TNC and VNC images and compared. Linear regression analysis of the CACS was performed between TNC and VNC images. The correlation of overall CACS from VNC and TNC images was very strong (r = 0.923, p < 0.001). The CACS from VNC images were lower than that from TNC images (221 versus. 69, p < 0.001). When the regression equation of the overall coronary artery was applied, the mean calibrated CACS-VNC was 221 which had a significant difference from the CACS-TNC (p = 0.017). When the regression equation of each coronary branch artery was applied, the mean calibrated CACS-VNC was 221, which had a significant difference from the CACS-TNC (p = 0.003). But the mean difference between the CACS-TNC and the calibrated CACS-VNC in either way was less than 1. The agreement on risk stratification with CACS-TNC and CCACS-VNC was almost perfect. This multicenter study with dual-layer spectral detector CT showed that it was feasible to calculate CACS from the VNC images derived from the spectral coronary artery CT angiography scan, and the results were in good accordance with the TNC images after correction. Therefore, the TNC scan could be omitted, reducing the radiation dose to patients and saving examination time while using dual-layer spectral detector CT.
Purpose: Myocardial contraction fraction (MCF) of cardiac magnetic resonance (CMR) was used to evaluate myocardial function in patients with hypertrophic cardiomyopathy (HCM), which may represent a proxy marker of disease severity in HCM. Materials and Methods: A total of 60 HCM patients and 20 healthy controls were examined with CMR. MCF was calculated by dividing left ventricular stroke volume by left ventricular myocardial volume. The difference in MCF between late gadolinium enhancement (LGE)-positive and LGE-negative patients were compared. The differences in MCF were compared among patients with stages Ⅱ, Ⅲ, and Ⅳ of HCM. Logistic regression analysis was used to detect independent discriminants of more severe HCM. Receiver operating characteristic analysis differentiated HCM with different clinical stages. Results: Compared with controls (110.67±20.40%, P <0.001), values for MCF were significantly reduced in HCM (61.40±15.60%). The MCF reduction in LGE detected by CMR was more significant than in HCM patients without LGE (53.15±10.67% vs. 76.72±11.04%, P <0.001). Patients with stage IV of HCM had the lowest MCF (45.36±10.97%, P <0.05 vs. stage II and III). Lower MCF remains an independent discriminator for more severe HCM (Stage Ⅱ vs. Stage Ⅲ, odds ratio: 0.85; Stage Ⅲ vs. Stage Ⅳ, odds ratio: 0.88, all P <0.05). The optimal cutoff value for detecting more severe HCM is MCF under 66.40% (Stage Ⅱ vs. Stage Ⅲ, P <0.05) and 44.75% (Stage Ⅲ vs. Stage Ⅳ, P <0.05). Conclusion: MCF may be a useful and simple tool to evaluate myocardial function in patients with HCM and provide an indicator of disease severity in individuals with HCM.
Background To facilitate the clinical use of cardiac T1ρ, it is important to understand the impact of age and sex on T1ρ values of the myocardium. Purpose To investigate the impact of age and gender on myocardial T1ρ values. Study Type Cross‐sectional. Population Two hundred ten healthy Han Chinese volunteers without cardiovascular risk factors (85 males, mean age 34.4 ± 12.5 years; 125 females, mean age 37.9 ± 14.8 years). Field Strength/Sequence 1.5 T; T1ρ‐prepared steady‐state free precession (T1ρ mapping) sequence. Assessment Basal, mid, and apical short‐axis left ventricular T1ρ maps were acquired. T1ρ maps acquired with spin‐lock frequencies of 5 and 400 Hz were subtracted to create a myocardial fibrosis index (mFI) map. T1ρ and mFI values across different age decades, sex, and slice locations were compared. Statistical Tests Shapiro–Wilk test, Student's t test, Mann–Whitney U test, linear regression analysis, one‐way analysis of variance and intraclass correlation coefficient. Significance: P value <0.05. Results Women had significantly higher T1ρ and mFI values than men (50.3 ± 2.0 msec vs. 47.7 ± 2.4 msec and 4.7 ± 1.0 msec vs. 4.3 ± 1.1 msec, respectively). Additionally, in males and females combined, there was a significant positive but weak correlation between T1ρ values and age ( r = 0.27), while no correlation was observed between the mFI values and age ( P = 0.969). Data Conclusion We report potential reference values for cardiac T1ρ by sex, age distribution, and slice location in a Chinese population. T1ρ was significantly correlated with age and sex, while mFI was only associated with sex. Evidence Level 2 Technical Efficacy Stage 1
ABSTRACT Background Cardiovascular disease prevalence remains high among chronic kidney disease (CKD) patients. Mechanisms and treatments to improve prognosis remain of paramount importance, and imaging biomarkers of left ventricular myocardial structure and function have better defined the phenotype of renal cardiomyopathy. The left atrial function and right heart remain are less well reported in CKD. This study used cardiac magnetic resonance imaging (CMR) to assess the interplay of left atrial and right ventricular function. Methods In a cross-sectional study, we examined 58 CKD patients (Group I: stages 2–3, n = 25; Group II: stages 4–5, n = 33). Additionally, 26 age-matched healthy controls were included. Comprehensive CMR protocols (1.5T) were employed, encompassing cine imaging, native T1 and T2 mapping, and tissue tracking strain analysis. Left ventricular (LV), right ventricular (RV) and left atrial (LA) structure, function and strain parameters were assessed. Results Compared with healthy controls, both Groups I and II exhibited impaired RV and LA function. right ventricular end-diastolic volume index and right ventricular end-systolic volume index showed significant increases in both Groups I and II (P < .001). All LV, RV and LA strain parameters were reduced in the patient groups (all P < .001). In the univariate binary logistic regression, several parameters, including age, blood pressure, RV volumes and LV/RV strain, were found to have a statistically significant association with CKD. In a multivariable model adjusted for other confounders, RV GLS and left atrial strain remained as independent significant predictors. Conclusions RV size, LA strain and volume assessed by CMR serve as markers of RV and LA cardiac dysfunction in CKD patients with preserved LVEF. Greater attention should be given to RV and LA dysfunction for early identification of cardiac dysfunction in CKD patients.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
