Cardiac function in patients with polymyositis or dermatomyositis: a three-dimensional speckle-tracking echocardiography study

Cardiac event is a major cause of death in patients with idiopathic inflammatory myopathies (IIM). The most frequent IIMs are polymyositis (PM) and dermatomyositis (DM). The purpose of this study was to analyze cardiac involvement by three-dimensional speckle-tracking echocardiography (3D STE) in patients with PM or DM, and to identify the relationship of cardiac injury with clinical characteristics and disease-specific parameters. 60 PM/DM patients with preserved left ventricular ejection fraction and 30 matched healthy controls were assessed by conventional echocardiography, 3D STE with biventricular strain analysis and electrocardiogram. Compared to controls, patients with PM/DM had significantly diminished left ventricular global longitudinal systolic strain and right ventricular longitudinal systolic strain (LVGLS, ? 20.3?±?2.5 vs. ? 23.4?±?1.7%; RVLS, ? 19.4?±?4.2 vs ? 24.8?±?2.0%; both P?<?0.001), and longer QTc intervals(421.0?±?38.4 vs 400.6?±?14.5 ms, P?=?0.001). Multiple regression analysis showed that Myositis Damage Index (MDI) was independently associated with LVGLS (R²?=?0.44, P?=?0.002) and RVLS (R²?=?0.56, P?<?0.001) in PM/DM patients with established disease course more than 1 year. In multivariate analysis of pooled data for all the PM/DM patients, when MDI was excluded due to missing observations, disease duration correlated with worse LVGLS (R²?=?0.24, P?=?0.002), while concomitant interstitial lung disease correlated with worse RVLS (R²?=?0.30, P?<?0.001). Disease activity scores (Myositis Intention to Treat Activities Index) had a weak positive correlation with QTc intervals (r_sp = 0.31, P?=?0.02). Our results suggest that cardiac injury in PM/DM is a long-term process and its severity depends on patients’ heterogeneous clinical features and systemic disease burden.     

Association with right atrial strain with right atrial pressure: an invasive validation study

Echocardiographic assessment of right atrial pressure (RAP) from inferior vena cava (RAP_IVC) dimension may underestimate catheter-derived (RAP_C). As right atrial (RA) deformation, measured by speckle tracking, is preload-dependent, we hypothesized that RA strain may improve estimation of RAP_C. Right atrial strain components [RA reservoir function (?R), peak RA contraction (?CT) and RA conduit function (?CD)] were measured in 125 of 175 patients who had echocardiography and invasive measures of RAP (median difference 1 day). To determine whether RA strain measures differentiated patients with correct vs incorrect RAP_IVC assessment, categories with RAP_IVC values?<?3, 8 and >?15 mmHg were compared with RAP_C groups?<?3, 4–7, 8–10, 11–14 and >?15 mmHg. Non-invasively determined RAP was significantly lower (p?=?0.001) than invasively determined RAP_C, with a weak correlation (r?=?0.35, p?<?0.001). RA strain components were associated with RA size, RV function and IVC size. In those with RAP_IVC?>?15 mmHg, half of patients were categorized into RAP?<?10 mmHg. There were no significant differences in RA characteristics that differentiated patients in whom echocardiographic estimation of RAP was inaccurate. Right atrial strain measures were feasible, and had associations with RA size, RV systolic function and IVC size. Right atrial strain was significantly different between those with normal vs raised pressure, but it did not identify those with incorrect echocardiographic assessment of RAP.     

Variability of native T1 values: implication for defining regional myocardial changes using MRI

The aim of the present study was to establish T1 variation (T1v) thresholds for duplicated measurements of regional T1 values in left ventricle (LV) using magnetic resonance imaging (MRI). Eighteen healthy volunteers were recruited to undergo two consecutive cardiac MRI scans using modified Look-Locker Inversion recovery (MOLLI) with two spatial resolutions on different days to repeat T1 measurements on LV. The absolute differences (d) and standard deviations (SDs) of regional T1 values were acquired with the two scans and two readers. T1v threshold (mean difference?+?2SD), intra-class correlation coefficient (ICC) and coefficient of variation (CoV) were calculated. T1 mapping using the MOLLI sequence (with multiple spatial resolutions) was successfully performed in all 18 volunteers twice. On a per-slice basis, ICCs for intra-observer, inter-observer, inter-resolution and inter-study T1v were 0.988, 0.899, 0.763 and 0.6. CoVs were 0.72, 2.39, 3.90 and 4.28%. T1v thresholds were 22, 66, 118 and 120 ms. On a per-segment basis, ICCs for intra-observer, inter-observer, inter-resolution and inter-study T1v were 0.974, 0.859, 0.711 and 0.594. CoVs were 1.09, 3.36, 4.69 and 5.01%. T1v thresholds were 33, 94, 140 and 144 ms. Those thresholds may be useful for discriminating disease-initiated T1v from random errors of T1 measurements.     

Cardiac myxoma: a contemporary multimodality imaging review

Cardiac myxoma (CM) is by far the most common primary benign cardiac tumor, typically arising in the left atrium with an attachment point in the fossa ovalis region. Although the etiology of CM remains unclear, we know that this endocardial-based mass originates from undifferentiated mesenchymal cells. Continuous technical improvements in the field of echocardiography since the 1960s has profoundly changed the diagnostic approach by allowing a good tumor detection as well as the preoperative planning by providing crucial information concerning the attachment point location. However, echocardiography has its limitations among which lack of tissue characterization and restricted field of view can arise diagnosis difficulties in atypical presentations. With the widespread and routine use of echocardiography and chest computed tomography (CT), incidental detection of CM is not infrequent. As a consequence, it has become mandatory for cardiologists and radiologists evolving in a multimodality imaging world to be familiar with the wide range of presentations of this tumor. The authors present here a review of the common and less common aspects of CM using the main imaging modalities available: echocardiography, cardiovascular magnetic resonance imaging, CT, positron emission tomography and coronary angiography.     

MHI-148 Cyanine Dye Conjugated Chitosan Nanomicelle with NIR Light-Trigger Release Property as Cancer Targeting Theranostic Agent

Purpose

Paclitaxel (PTX) loaded hydrophobically modified glycol chitosan (HGC) micelle is biocompatible in nature, but it requires cancer targeting ability and stimuli release property for better efficiency. To improve tumor retention and drug release characteristic of HGC-PTX nanomicelles, we conjugated cancer targeting heptamethine dye, MHI-148, which acts as an optical imaging agent, targeting moiety and also trigger on-demand drug release on application of NIR 808 nm laser.

Procedures

The amine group of glycol chitosan modified with hydrophobic 5β-cholanic acid and the carboxyl group of MHI-148 were bonded by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide chemistry. Paclitaxel was loaded to MHI-HGC nanomicelle by an oil-in-water emulsion method, thereby forming MHI-HGC-PTX.

Results

Comparison of near infrared (NIR) dyes, MHI-148, and Flamma-774 conjugated to HGC showed higher accumulation for MHI-HGC in 4T1 tumor and 4T1 tumor spheroid. In vitro studies showed high accumulation of MHI-HGC-PTX in 4T1 and SCC7 cancer cell lines compared to NIH3T3 cell line. In vivo fluorescence imaging of the 4T1 and SCC7 tumor showed peak accumulation of MHI-HGC-PTX at day 1 and elimination from the body at day 6. MHI-HGC-PTX showed good photothermal heating ability (50.3 °C), even at a low concentration of 33 μg/ml in 1 W/cm² 808 nm laser at 1 min time point. Tumor reduction studies in BALB/c nude mice with SCC7 tumor showed marked reduction in MHI-HGC-PTX in the PTT group combined with photothermal therapy compared to MHI-HGC-PTX in the group without PTT.

Conclusion

MHI-HGC-PTX is a cancer theranostic agent with cancer targeting and optical imaging capability. Our studies also showed that it has cancer targeting property independent of tumor type and tumor reduction property by combined photothermal and chemotherapeutic effects.

     

Improved Differentiation of Low-Grade and High-Grade Gliomas and Detection of Tumor Proliferation Using APT Contrast Fitted from Z-Spectrum

Purpose

The purpose of the study is to demonstrate the value of quantitative amide proton transfer (APT) imaging for differentiating glioma grades and detecting tumor proliferation.

Procedures

This study included 32 subjects with 16 low-grade gliomas (LGG) and 16 high-grade gliomas (HGG) confirmed by histopathology. Chemical exchange saturation transfer (CEST) magnetic resonance imaging with APT weighting was performed on a 3 T scanner. After B₀ correction, Z-spectra were fitted with Lorentzian functions corresponding to the upfield semi-solid magnetization transfer and nuclear overhauser enhancement (MT&NOE) effect, the direct saturation (DS) effect, and the downfield APT effect centered at around ??1.5, 0, and +?3.5 ppm, respectively. To compute the Z-spectral fitted APT (fitted_APT) in solid tumor tissue, double-peak histogram fitting of pixel MT&NOE effect from the whole tumor was used to remove necrosis regions. The fitted APT was then compared with the conventional APT based on magnetization transfer ratio asymmetry. Receiver operating characteristic (ROC) analysis was used to compare the performance between Z-spectral fitted contrasts and the con_APT for LGG versus HGG differentiation. Additionally, the correlations between the imaging contrasts (fitted_APT, con_APT, and fitted_MT&NOE) and Ki-67 labeling index for tumor proliferation were also evaluated.

Results

Z-spectral fitted_APT shows improved statistical power for differentiating HGG and LGG (7.58?±?0.99 vs. 6.79?±?1.05 %, p?<?0.05) than con_APT (4.34?±?0.95 vs. 4.05?±?2.02 %, p?>?0.05) in solid tumor tissues. Analyses of whole tumor, on the other hand, have less differentiating power for both fitted_APT (p from 0.032 to 0.08) and con_APT (p from 0.696 to 0.809). Similarly, based on ROC analyses, fitted_APT shows larger area under the curve (AUC?=?0.723) than con_APT (AUC?=?0.543). The combination of fitted APT, DS, and MT&NOE further improved the specificity (75 %), diagnostic accuracy (78.2 %), and area under the curve (0.758) in differentiating LGG and HGG. Consistently, fitted_APT (r?=?0.451, p?=?0.018) is better correlated with Ki-67 than con_APT (r?=?0.331, p?=?0.092).

Conclusions

Fitted APT from Z-spectrum improves differentiation of low- and high-grade gliomas and better correlated with tumor proliferation than conventional APT.

     

Assessment of Remote Myocardium Heterogeneity in Patients with Ventricular Tachycardia Using Texture Analysis of Late Iodine Enhancement (LIE) Cardiac Computed Tomography (cCT) Images

Purpose

Diffuse remodeling of myocardial extra-cellular matrix is largely responsible for left ventricle (LV) dysfunction and arrhythmias. Our hypothesis is that the texture analysis of late iodine enhancement (LIE) cardiac computed tomography (cCT) images may improve characterization of the diffuse extra-cellular matrix changes. Our aim was to extract volumetric extracellular volume (ECV) and LIE texture features of non-scarred (remote) myocardium from cCT of patients with recurrent ventricular tachycardia (rVT), and to compare these radiomic features with LV-function, LV-remodeling, and underlying cardiac disease.

Procedures

Forty-eight patients suffering from rVT were prospectively enrolled: 5/48 with idiopathic VT (IVT), 23/48 with post-ischemic dilated cardiomyopathy (ICM), 9/48 with idiopathic dilated cardiomyopathy (IDCM), and 11/48 with scars from a previous healed myocarditis (MYO). All patients underwent echocardiography to assess LV systolic and diastolic function and cCT with pre-contrast, angiographic, and LIE scan to obtain end-diastolic volume (EDV), ECV, and first-order texture parameters of Hounsfield Unit (HU) of remote myocardium in LIE [energy, entropy, HU-mean, HU-median, standard deviation (SD), and mean absolute deviation (MAD)].

Results

Energy, HU mean, and HU median by cCT texture analysis correlated with ECV (rho?=?0.5650, rho?=?0.5741, rho?=?0.5068; p?<?0.0005). cCT-derived ECV, HU-mean, HU-median, SD, and MAD correlated directly to EDV by cCT and inversely to ejection fraction by echocardiography (p?<?0.05). SD and MAD correlated with diastolic function by echocardiography (rho?=?0.3837, p?=?0.0071; rho?=?0.3330, p?=?0.0208). MYO and IVT patients were characterized by significantly lower values of SD and MAD when compared with ICM and IDCM patients, independently of LV-volume systolic and diastolic function.

Conclusions

Texture analysis of LIE may expand cCT capability of myocardial characterization. Myocardial heterogeneity (SD and MAD) was associated with LV dilatation, systolic and diastolic function, and is able to potentially identify the different patterns of structural remodeling characterizing patients with rVT of different etiology.