[Early Assessment of Myocardial Fibrosis of Hypertrophic Cardiomyopathy with Native-T1-Mapping-Based Deep Learning: A Preliminary Study].

OBJECTIVE: To explore the diagnostic performance of deep learning (DL) model in early detection of the interstitial myocardial fibrosis using native T1 maps of hypertrophic cardiomyopathy (HCM) without late gadolinium enhancement (LGE). METHODS: Sixty HCM patients and 44 healthy volunteers who underwent cardiac magnetic resonance were enrolled in this study. Each native T1 map was labeled according to its LGE status. Then, native T1 maps of LGE (-) and those of the controls were preprocessed and entered in the SE-ResNext-50 model as the matrix for the DL model for training, validation and testing. RESULTS: A total of 241 native T1 maps were entered in the SE-ResNext-50 model. The model achieved a specificity of 0.87, sensitivity of 0.79, and area under curve ( AUC) of 0.83 ( P<0.05) in distinguishing native T1 maps of LGE (-) from those of the controls in the testing set. CONCLUSION: The DL model based on SE-ResNext-50 could be used for identifying native T1 maps of LGE (-) with relatively high accuracy. It is a promising approach for early detection of myocardial fibrosis in HCM without the use of contrast agent.

Noninvasive oxygenation assessment after acute myocardial infarction with breathing maneuvers-induced oxygenation-sensitive magnetic resonance imaging.

The safety profiles when performing stress oxygenation-sensitive magnetic resonance imaging (OS-MRI) have raised concerns in clinical practice. Adenosine infusion can cause side effects such as chest pain, dyspnea, arrhythmia, and even cardiac death. The aim of this study was to investigate the feasibility of breathing maneuvers-induced OS-MRI in acute myocardial infarction (MI). This was a prospective study, which included 14 healthy rabbits and nine MI rabbit models. This study used 3 T MRI/modified Look-Locker inversion recovery sequence for native T1 mapping, balanced steady-state free precession sequence for OS imaging, and phase-sensitive inversion recovery sequence for late gadolinium enhancement. The changes in myocardial oxygenation (ΔSI) were assessed under two breathing maneuvers protocols in healthy rabbits: a series of extended breath-holding (BH), and a combined maneuver of hyperventilation followed by the extended BH (HVBH). Subsequently, OS-MRI with HVBH in acute MI rabbits was performed, and the ΔSI was compared with that of adenosine stress protocol. Student's t-test, Wilcoxon rank test, and Friedman test were used to compare ΔSI in different subgroups. Pearson and Spearman correlation was used to obtain the association of ΔSI between breathing maneuvers and adenosine stress. Bland-Altman analysis was used to assess the bias of ΔSI between HVBH and adenosine stress. In healthy rabbits, BH maneuvers from 30 to 50 s induced significant increase in SI compared with the baseline (all p < 0.05). By contrast, hyperventilation for 60 s followed by 10 s-BH (HVBH 10 s) exhibited a comparable ΔSI to that of stress test (p = 0.07). In acute MI rabbits, HVBH 10 s-induced ΔSIs among infarcted, salvaged, and the remote myocardial area were no less effectiveness than adenosine stress when performing OS-MRI (r = 0.84; p < 0.05). Combined breathing maneuvers with OS-MRI have the potential to be used as a nonpharmacological alternative for assessing myocardial oxygenation in patients with acute MI. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

[Clinical Study of Rs-EPI DWI to Improve Imaging Quality and Assessment on Intracranial Mass Lesions].

OBJECTIVES: To explore the clinical value of readout-segmented echo planar imaging (Rs-EPI) sequence in the assessment of intracranial mass lesions compared to the standard single-shot EPI (Ss-EPI) sequence. METHODS: We included 21 patients with intracranial mass lesions who underwent both Ss-EPI diffusion weighted imaging (DWI) and Rs-EPI DWI at 3.0T MR scanner with a twenty-channel head-neck coil. The quality of images was assessed by two experienced radiologists independently. The differences in image quality between two sequences were analyzed using Wilcoxon signed-rank test. Inter-observer agreements were analyzed using interclass correlation coefficient (ICC) and Kappa test. RESULTS: All objectives were completed on 3.0T MR. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in Rs-EPI DWI were higher than those in Ss-EPI DWI (130.46±49.10 vs. 71.58±30.43, P=0.000; 33.22±18.86 vs. 17.92±18.72, P=0.003). The scores of overall image quality, ghost artifact where next to the paranasal sinuses, mastoid air cells and frontal sinus of Rs-EPI DWI were significantly higher than those of Ss-EPI DWI. Meanwhile, the geometric distortion of anatomical structures of Rs-EPI DWI were significantly lower compared to Ss-EPI DWI sequence (0.016±0.021 vs. 0.037±0.069, P=0.00). The inter-reader and intra-reader agreements for the assessment of qualitative parameters were good [0.74≤Kappa value or ICC≤0.92]. CONCLUSIONS: Rs-EPI DWI sequence is a potential technique to improve the imaging quality in the diagnosis of intracranial mass lesions.

Therapeutic efficacy of PCSK9 monoclonal antibodies in statin-nonresponsive patients with hypercholesterolemia and dyslipidemia: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: Heterozygous familial hypercholesterolemia and dyslipidemia are the predominant causes for cardiovascular disease (CVD). Clinical guidelines for lowering CVD risk have advocated that low density lipoprotein-cholesterol (LDL-C) must be reduced. The primary choice of therapy for controlling lipidemia has been statins, which are not completely effective. Proprotein convertase subtilisin/kexin type-9 (PCSK9), which interferes with LDL clearance from circulation, inversely relates to the LDL-C levels. The loss of statin efficacy is likely due to increased circulating PCSK9 and antibody therapy against PCSK9 has been found to be efficacious in lowering LDL-C. In this study, we evaluated the efficacy of PCSK9-mAbs for lowering LDL-C, in statin non-responsive hypercholesterolemia patients. STUDY DESIGN AND METHODS: PubMed, EMBASE, Scholar, Web of Science and Scopus databases were searched to identify randomized controlled trials of PCSK9 antibody-statin combination vs statin, published till 2015. Two reviewers independently screened the articles, and a collective decision was reached about the included studies in the metaanalysis. Parameters analyzed: change from baseline in LDL-C, high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC); ApoB and ApoA1 levels. RESULTS: A total of 12 studies with 4909 patients were selected. Overall, add-on therapy with PCSK9-mAb to the ongoing statin therapy was found to achieve greater reduction in LDL-C, ApoB, TC, compared to statin therapy. There were no major treatment emergent adverse effects due to PCSK9-mAb therapy. CONCLUSIONS: In adult patients with heterozygous familial hypercholesterolemia and dyslipidemia, PCSK9-mAb therapy in combination with statins was able to achieve the goal of lowering LDL-C.