Late gadolinium enhancement(LGE) cardiovascular magnetic resonance(CMR) is the gold standard for imaging myocardial viability.An important application of LGE CMR is the assessment of the location and extent of the myo...Late gadolinium enhancement(LGE) cardiovascular magnetic resonance(CMR) is the gold standard for imaging myocardial viability.An important application of LGE CMR is the assessment of the location and extent of the myocardial scar in patients with ventricular tachycardia(VT), which allows for more accurate identification of the ablation targets.However, a large percentage of patients with VT have cardiac implantable electronic devices(CIEDs), which is a relative contraindication for cardiac magnetic resonance imaging due to safety and image artifact concerns.Previous studies showed that these patients can be safely scanned on 1.5 T scanners provided that an adequate imaging protocol is adopted.Nevertheless, imaging patients with a CIED result in metal artifacts due to the strong frequency off-resonance effects near the device; therefore, the spins in the surrounding myocardium are not completely inverted, and thus give rise to hyperintensity artifacts.These artifacts obscure the myocardial scar tissue and limit the ability to study the correlation between the myocardial scar structure and the electro-anatomical map during catheter ablation.In this study, we developed a modified inversion recovery technique to alleviate the CIED-induced metal artifacts and improve the diagnostic image quality of LGE images in patients with CIEDs without increasing scan time or requiring additional hardware.The developed technique was tested in phantom experiments and in vivo scans, which showed its capability for suppressing the hyperintensity artifacts without compromising myocardium nulling in the resulting LGE images.展开更多
Purpose: Myocardial fibrosis causes cardiac dysfunction, arrhythmias, and sudden death. Tagging imaging on cardiovascular MR can measure the intra-myocardial motion from the dynamic deformation of lines superimposed o...Purpose: Myocardial fibrosis causes cardiac dysfunction, arrhythmias, and sudden death. Tagging imaging on cardiovascular MR can measure the intra-myocardial motion from the dynamic deformation of lines superimposed on the myocardium. The purpose of this study was to evaluate the detectability of myocardial fibrosis using tagging imaging and to compare this with conventional cine imaging. Materials and Methods: We reviewed 4 normal control (NML) subjects, 4 patients with myocarditis (MYO), and 4 patients with old myocardial infarction (ICM). We measured circumferential strain (Ecc) from tagging imaging, and regional wall thickening (rWT) from cine imaging. Fibrosis was determined from a late gadolinium enhancement (LGE) image. We evaluate diagnostic performance by comparing values of the area under curve (AUC) using ROC analysis. Results: Mean values of Ecc and rWT decreased in the area of LGE both in MYO and ICM patients. AUC values of Ecc and rWT in all subjects were 0.98 and 0.84, respectively (p < 0.0001). These values in MYO patients were 0.95 and 0.72 (p = 0.007), respectively, and 0.99 and 0.75, respectively, in ICM patients (p = 0.0008). Conclusions: Both Ecc and rWT decreased in the area with fibrosis in the patients with MYO and ICM. Tagging imaging showed better detectability of myocardial fibrosis than did cine imaging.展开更多
Myocardial fiber deformation measurements have been reported to be associated with adverse outcomes in patients with acute heart failure and those with myocardial infarction.However,few studies have addressed the prog...Myocardial fiber deformation measurements have been reported to be associated with adverse outcomes in patients with acute heart failure and those with myocardial infarction.However,few studies have addressed the prognostic value of global circumferential strain(GCS)in dilated cardiomyopathy(DCM)patients with severely impaired systolic function.This study aimed to evaluate the prognostic value of cardiac magnetic resonance(CMR)-derived GCS in DCM patients with severely reduced ejection.Consecutive DCM patients with severely reduced ejection fraction(EF<35%)who underwent CMR were included.GCS was calculated from CMR cine images.The clinical endpoint was a composite of all-cause mortality,heart transplantation,implantable cardioverter defibrillator(ICD)implantation and aborted sudden cardiac death(SCD).A total of 129 patients with a mean EF of 15.33%(11.36%–22.27%)were included.During a median follow-up of 518 days,endpoint events occurred in 50 patients.Patients with GCS≥the median(−5.17%)had significantly reduced event-free survival as compared with those with GCS<the median(P<0.01).GCS was independently associated with adverse events after adjusting for clinical and imaging risk factors including extent of late gadolinium enhancement(LGE)(P<0.05).Adding GCS into the model including the extent of LGE resulted in significant improvements in the C-statistic(from 0.706 to 0.742;P<0.05)with a continuous net reclassification improvement(NRI)of 29.71%.It was concluded that GCS derived from CMR could be useful for risk stratification in DCM patients with severely reduced EF,which may increase common imaging risk factors including LGE.展开更多
Cardiac involvement of sarcoid lesions is diagnosed by myocardial biopsy which is frequently false-negative,and patients with cardiac sarcoidosis(CS) who have impaired left ventricular(LV) systolic function are someti...Cardiac involvement of sarcoid lesions is diagnosed by myocardial biopsy which is frequently false-negative,and patients with cardiac sarcoidosis(CS) who have impaired left ventricular(LV) systolic function are sometimes diagnosed with dilated cardiomyopathy(DCM).Late gadolinium enhancement(LE) in magnetic resonance imaging is now a critical finding in diagnosing CS,and the novel Japanese guideline considers myocardial LE to be a major criterion of CS.This article describes the value of LE in patients with CS who have impaired LV systolic function,particularly the diagnostic and clinical significance of LE distribution in comparison with DCM.LE existed at all LV segments and myocardial layers in patients with CS,whereas it was localized predominantly in the midwall of basal to mid septum in those with DCM.Transmural(nodular),circumferential,and subepicardial and subendocardial LE distribution were highly specific in patients with CS,whereas the prevalence of striated midwall LE were high both in patients with CS and with DCM.Since sarcoidosis patients with LE have higher incidences of heart failure symptoms,ventricular tachyarrhythmia and sudden cardiac death,the analyses of extent and distribution of LE are crucial in early diagnosis and therapeutic approach for patients with CS.展开更多
Substrate characterization is the mainstay of ablation for ventricular tachycardia(VT).Although the use of electroanatomic voltage mapping(EAVM)in the electrophysiology(EP)laboratory has enabled real-time approximatio...Substrate characterization is the mainstay of ablation for ventricular tachycardia(VT).Although the use of electroanatomic voltage mapping(EAVM)in the electrophysiology(EP)laboratory has enabled real-time approximation of myocardial scar,it has limitations.This is related to the subjective and tedious nature of voltage mapping and the challenges of defi ning the transmurality of scar.Various noninvasive methods of scar assessment have emerged,with magnetic resonance imaging(MRI)being the most accurate.Integrated MRI and electroanatomic voltage mapping studies demonstrate good correlation.Nonetheless,MRI has advantages.These include(1)preprocedure identifi cation of epicardial and intramural scar,(2)assessment of ablative lesion formation after unsuccessful ablations,(3)identifi-cation of heterogeneous regions of scar,where critical conducting channels are likely to occur,and(4)predictive value in the assessment of sudden cardiac death(SCD).Integration of scar imaging in ventricular tachycardia ablation and risk stratifi cation has great potential to advance the practice of arrhythmia management.展开更多
文摘Late gadolinium enhancement(LGE) cardiovascular magnetic resonance(CMR) is the gold standard for imaging myocardial viability.An important application of LGE CMR is the assessment of the location and extent of the myocardial scar in patients with ventricular tachycardia(VT), which allows for more accurate identification of the ablation targets.However, a large percentage of patients with VT have cardiac implantable electronic devices(CIEDs), which is a relative contraindication for cardiac magnetic resonance imaging due to safety and image artifact concerns.Previous studies showed that these patients can be safely scanned on 1.5 T scanners provided that an adequate imaging protocol is adopted.Nevertheless, imaging patients with a CIED result in metal artifacts due to the strong frequency off-resonance effects near the device; therefore, the spins in the surrounding myocardium are not completely inverted, and thus give rise to hyperintensity artifacts.These artifacts obscure the myocardial scar tissue and limit the ability to study the correlation between the myocardial scar structure and the electro-anatomical map during catheter ablation.In this study, we developed a modified inversion recovery technique to alleviate the CIED-induced metal artifacts and improve the diagnostic image quality of LGE images in patients with CIEDs without increasing scan time or requiring additional hardware.The developed technique was tested in phantom experiments and in vivo scans, which showed its capability for suppressing the hyperintensity artifacts without compromising myocardium nulling in the resulting LGE images.
文摘Purpose: Myocardial fibrosis causes cardiac dysfunction, arrhythmias, and sudden death. Tagging imaging on cardiovascular MR can measure the intra-myocardial motion from the dynamic deformation of lines superimposed on the myocardium. The purpose of this study was to evaluate the detectability of myocardial fibrosis using tagging imaging and to compare this with conventional cine imaging. Materials and Methods: We reviewed 4 normal control (NML) subjects, 4 patients with myocarditis (MYO), and 4 patients with old myocardial infarction (ICM). We measured circumferential strain (Ecc) from tagging imaging, and regional wall thickening (rWT) from cine imaging. Fibrosis was determined from a late gadolinium enhancement (LGE) image. We evaluate diagnostic performance by comparing values of the area under curve (AUC) using ROC analysis. Results: Mean values of Ecc and rWT decreased in the area of LGE both in MYO and ICM patients. AUC values of Ecc and rWT in all subjects were 0.98 and 0.84, respectively (p < 0.0001). These values in MYO patients were 0.95 and 0.72 (p = 0.007), respectively, and 0.99 and 0.75, respectively, in ICM patients (p = 0.0008). Conclusions: Both Ecc and rWT decreased in the area with fibrosis in the patients with MYO and ICM. Tagging imaging showed better detectability of myocardial fibrosis than did cine imaging.
基金the National Natural Science Foundation of China(Nos.81701653 and 81570348).
文摘Myocardial fiber deformation measurements have been reported to be associated with adverse outcomes in patients with acute heart failure and those with myocardial infarction.However,few studies have addressed the prognostic value of global circumferential strain(GCS)in dilated cardiomyopathy(DCM)patients with severely impaired systolic function.This study aimed to evaluate the prognostic value of cardiac magnetic resonance(CMR)-derived GCS in DCM patients with severely reduced ejection.Consecutive DCM patients with severely reduced ejection fraction(EF<35%)who underwent CMR were included.GCS was calculated from CMR cine images.The clinical endpoint was a composite of all-cause mortality,heart transplantation,implantable cardioverter defibrillator(ICD)implantation and aborted sudden cardiac death(SCD).A total of 129 patients with a mean EF of 15.33%(11.36%–22.27%)were included.During a median follow-up of 518 days,endpoint events occurred in 50 patients.Patients with GCS≥the median(−5.17%)had significantly reduced event-free survival as compared with those with GCS<the median(P<0.01).GCS was independently associated with adverse events after adjusting for clinical and imaging risk factors including extent of late gadolinium enhancement(LGE)(P<0.05).Adding GCS into the model including the extent of LGE resulted in significant improvements in the C-statistic(from 0.706 to 0.742;P<0.05)with a continuous net reclassification improvement(NRI)of 29.71%.It was concluded that GCS derived from CMR could be useful for risk stratification in DCM patients with severely reduced EF,which may increase common imaging risk factors including LGE.
文摘Cardiac involvement of sarcoid lesions is diagnosed by myocardial biopsy which is frequently false-negative,and patients with cardiac sarcoidosis(CS) who have impaired left ventricular(LV) systolic function are sometimes diagnosed with dilated cardiomyopathy(DCM).Late gadolinium enhancement(LE) in magnetic resonance imaging is now a critical finding in diagnosing CS,and the novel Japanese guideline considers myocardial LE to be a major criterion of CS.This article describes the value of LE in patients with CS who have impaired LV systolic function,particularly the diagnostic and clinical significance of LE distribution in comparison with DCM.LE existed at all LV segments and myocardial layers in patients with CS,whereas it was localized predominantly in the midwall of basal to mid septum in those with DCM.Transmural(nodular),circumferential,and subepicardial and subendocardial LE distribution were highly specific in patients with CS,whereas the prevalence of striated midwall LE were high both in patients with CS and with DCM.Since sarcoidosis patients with LE have higher incidences of heart failure symptoms,ventricular tachyarrhythmia and sudden cardiac death,the analyses of extent and distribution of LE are crucial in early diagnosis and therapeutic approach for patients with CS.
文摘Substrate characterization is the mainstay of ablation for ventricular tachycardia(VT).Although the use of electroanatomic voltage mapping(EAVM)in the electrophysiology(EP)laboratory has enabled real-time approximation of myocardial scar,it has limitations.This is related to the subjective and tedious nature of voltage mapping and the challenges of defi ning the transmurality of scar.Various noninvasive methods of scar assessment have emerged,with magnetic resonance imaging(MRI)being the most accurate.Integrated MRI and electroanatomic voltage mapping studies demonstrate good correlation.Nonetheless,MRI has advantages.These include(1)preprocedure identifi cation of epicardial and intramural scar,(2)assessment of ablative lesion formation after unsuccessful ablations,(3)identifi-cation of heterogeneous regions of scar,where critical conducting channels are likely to occur,and(4)predictive value in the assessment of sudden cardiac death(SCD).Integration of scar imaging in ventricular tachycardia ablation and risk stratifi cation has great potential to advance the practice of arrhythmia management.
