Imaging of the Silicone Implant with a 3D SPACE MR Sequence: The Accuracy for Estimating Implant Volume and Reconstructing Implant Deformation in Breast Surgery.

OBJECTIVE: The study is to assess the accuracy and reliability of 3D simulated magnetic resonance imaging with SPACE sequence for estimating implant volume and reconstructing implant deformation, which may assist in the diagnosis of implant complications and making individualized surgical plans for these patients. METHODS: MRI examinations of ten silicone implants were performed with T2, H2O-excitation SPACE sequence (T2-spc-H2O) and silicone-excitation SPACE sequence (T2-spc-Silicone) to find the most accurate method to estimate implant volume by ITK-SNAP. The effect of implant deformation and voxel size of silicone-excitation SPACE sequence on volume measurement was investigated. Thirteen normal patients and ten patients with implant complications (Wuhan Tongji Hospital from March 2017 to May 2019) were enrolled for testing the accuracy and reliability of 3D simulated MRI with silicone-excitation SPACE sequences for volume measurement and reconstructing implant deformation in patients. RESULTS: The absolute volume differences of T2-spc-Silicone group were significantly less than T2-spc-H2O and T2 group (6.28 vs. 23.27 vs. 42.19 mL, P < 0.05) in vitro. No significant difference was found between the normality group and the deformation group for estimating the volume of implants. Besides, the voxel size of T2-spc-Silicone from 0.5 × 0.5 × 0.5 mm to 5.0 × 5.0 × 5.0 mm did not significantly affect the accuracy of volume measurement of the implants in deformation state. However, 3D images of the implant became blurred with the voxel size increased. With the voxel size larger than 1.5 × 1.5 × 1.5 mm, the scores of image quality decreased significantly. The number of folds could not be identified accurately with the voxel size larger than 2.0 × 2.0 × 2.0 mm. In normal patients, the measurement errors of T2-spc-Silicone were around 10 mL. In the patients with implant complications, there was no significant difference between measured volume and the actual volume of implants. Moreover, implant deformations were clearly presented by T2-spc-Silicone with the voxel size of 1.0 × 1.0 × 1.0 mm. The results showed excellent intraobserver reliability (ICC = 0.997 > 0.8), and internal consistency ranged from 0.986 to 0.997 (P < 0.001). CONCLUSIONS: The method to measure implant volume by 3D simulated magnetic resonance imaging with T2-spc-Silicone sequence had possessed desirable accuracy and reliability. The deformation of the implant and the voxel size of the T2-spc-Silicone sequence didn't exhibit a significant effect on the accuracy of the measurement. T2-spc-Silicone with voxel size less than 2.0 × 2.0 × 2.0 mm could be used for 3D reconstruction of the implant deformation. The 1.0 × 1.0 × 1.0 mm was a suitable voxel size to reconstruct implant deformation clearly and quickly. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Sex-Related Differences of Left Atrial Strain in Patients With Hypertension Using Cardiac Magnetic Resonance Feature Tracking.

PURPOSE: Previous studies demonstrated the impact of sex on left ventricular (LV) strain in patients with essential hypertension. However, little is known about the effect of sex on left atrial (LA) strain in patients with hypertension. This study aimed to explore the sex-related differences of LA strain by using cardiac magnetic resonance feature tracking in patients with hypertension and preserved LV ejection fraction. MATERIALS AND METHODS: One hundred and fifty hypertensive patients (100 men and 50 women) and 105 age-matched and sex-matched normotensive controls (70 men and 35 women) were retrospectively enrolled and underwent cardiac magnetic resonance examination. LA strain parameters included LA reservoir strain (εs), conduit strain (εe), pump strain (εa), and their corresponding strain rate (SRs, SRe, and SRa). RESULTS: Men had significantly higher LV mass index, lower εs and εe than women in both patients and controls (all P <0.05). LA strain and strain rate were significantly reduced in hypertensive patients compared with controls, both in men and women (all P <0.05). In men, hypertension and its interaction were associated with increased LV mass index and decreased εs and εe. In multivariable analysis, men, LV ejection fraction, and LA minimum volume index remained independent determinants of εs and εe in all hypertensive patients (all P <0.05). CONCLUSION: LA strain was significantly impaired in hypertensive patients, and men had more impaired LA strain than women. These findings further emphasize the sex-related differences in the response of LA strain to hypertension in the early stage.

The relationship between epicardial adipose tissue thickness and arrhythmias in patients with hypertension: a 3.0T cardiac magnetic resonance study.

OBJECTIVES: To investigate the relationship between epicardial adipose tissue (EAT) thickness using cardiac magnetic resonance imaging (CMR) and arrhythmias in hypertensive patients. METHODS: Fifty-four hypertensive patients with arrhythmias (HTN [arrhythmias+]), 79 hypertensive patients without arrhythmias (HTN [arrhythmias-]), and 39 normal controls were retrospectively enrolled. EAT thickness was measured on cine images. Analysis of covariance with Bonferroni's post hoc correction, Pearson or Spearman analysis, receiver operating characteristic curve, and intraclass correlation coefficient analysis were performed. RESULTS: All hypertensive patients had impaired left ventricular (LV) and left atrial (LA) myocardial deformation, and HTN (arrhythmias+) patients displayed higher LV myocardial native T1, LA volume index, and increased EAT thickness than HTN (arrhythmias-) patients and normotensive controls. The presence of LV late gadolinium enhancement (LGE) was higher in hypertensive patients with arrhythmias than in those without arrhythmias. EAT thickness metrics significantly correlated with age, systolic blood pressure, body mass index, triglycerides and high-density lipoprotein levels, LV mass index and native T1 (all p < 0.05). EAT thickness parameters were able to differentiate hypertensive patients with arrhythmias from those without arrhythmias and normal controls, and the right ventricular free wall had the highest diagnostic performance. CONCLUSION: An accumulation of EAT thickness could further induce cardiac remodeling, promote myocardial fibrosis, and exaggerate function in hypertensive patients with arrhythmias. ADVANCES IN KNOWLEDGE: CMR-derived EAT thickness metrics could be a useful imaging marker for differentiating hypertensive patients with arrhythmias, which might be a potential target for the prevention of cardiac remodeling and arrhythmias.

The correlation of left atrial dysfunction and amyloid load in patients with immunoglobulin light-chain cardiac amyloidosis: a 3T cardiac magnetic resonance study.

OBJECTIVE: To investigate the left atrial (LA) changes in immunoglobulin light-chain cardiac amyloidosis (AL-CA) patients with different risk stratifications and to explore the correlation between LA function and the degree of amyloid load using cardiac magnetic resonance (CMR) imaging. METHODS: Forty-three AL-CA patients were retrospectively enrolled and were divided into low-to-moderate-risk group (n = 16, increased NT-proBNP or troponin I, or both normal) and high-risk group (n = 27, increased NT-proBNP and troponin I). 20 healthy individuals matched for age and gender were included. The function, myocardial deformation of left heart, and left ventricular (LV) tissue characterization among the three groups were compared. The correlation between LA function and LV tissue characterization was investigated. RESULTS: Compared with the controls, the AL-CA patients had a larger LA volume, lower left atrial emptying fraction (LAEF) and impaired left atrial strain (LAS). The high-risk group exhibited lower reservoir and booster function and increased LV extracellular volume (LV-ECV) than the low-to-moderate-risk group (p < 0.05). LV-ECV was significantly correlated with LAS and LAEF (all p < 0.05) but not LAEFconduit. The LAS and LAEF had a good diagnostic ability for risk stratification of AL-CA patients (area under the curve, 0.70 ~ 0.72). CONCLUSION: High-risk AL-CA patients showed more severe LA function impairment than low-to-moderate-risk AL-CA patients. LAS and LAEF were closely associated with LV-ECV in AL-CA patients, LAS and LAEF exhibited good capability to differentiate AL-CA patients of different risk stratifications. ADVANCES IN KNOWLEDGE: CMR-derived LAS and LAEF were correlated with amyloid load, allowing for differentiation of AL-CA patients at different risk stages.

Comparison of Various Parameters of DWI in Distinguishing Solitary Pulmonary Nodules.

In order to prospectively assess various parameters of diffusion weighted imaging (DWI) in differential diagnosis of benign and malignant solitary pulmonary nodules (SPNs), 58 patients (40 men and 18 women, and mean age of 48.1±10.4 years old) with SPNs undergoing conventional MR, DWI using b=500 s/mm2 on a 1.5T MR scanner, were studied. Various DWI parameters [apparent diffusion coefficient (ADC), lesion-tospinal cord signal intensity ratio (LSR), signal intensity (SI) score] were calculated and compared between malignant and benign SPNs groups. A receiver operating characteristic (ROC) curve analysis was employed to compare the diagnostic capabilities of all the parameters for discrimination between benign and malignant SPNs. The results showed that there were 42 malignant and 16 benign SPNs. The ADC was significantly lower in malignant SPNs (1.40±0.44)×10-3 mm2/s than in benign SPNs (1.81±0.58)×10-3 mm2/s. The LSR and SI scores were significantly increased in malignant SPNs (0.90±0.37 and 2.8±1.2) as compared with those in benign SPNs (0.68±0.39 and 2.2±1.2). The area under the ROC curves (AUC) of all parameters was not significantly different between malignant SPNs and benign SPNs. It was suggested that as three reported parameters for DWI, ADC, LSR and SI scores are all feasible for discrimination of malignant and benign SPNs. The three parameters have equal diagnostic performance.