Journal of Cardiovascular Magnetic Resonance - Most viewed articles

Myocardial first-pass perfusion cardiovascular magnetic resonance: history, theory, and current state of the art

2008-04-28

In less than two decades, first-pass perfusion cardiovascular magnetic resonance (CMR) has undergone a wide range of changes with the development and availability of improved hardware, software, and contrast agents, in concert with a better understanding of the mechanisms of contrast enhancement. The following review provides a perspective of the historical development of first-pass CMR, the developments in pulse sequence design and contrast agents, the relevant animal models used in early preclinical studies, the mechanism of artifacts, the differences between 1.5T and 3T scanning, and the relevant clinical applications and protocols. This comprehensive overview includes a summary of the past clinical performance of first-pass perfusion CMR and current clinical applications using state-of-the-art methodologies.

Quantitative characterization of myocardial infarction by cardiovascular magnetic resonance predicts future cardiovascular events in patients with ischemic cardiomyopathy

2008-04-09

Background: Cardiovascular magnetic resonance (CMR) can provide quantitative data of the myocardial tissue utilizing high spatial and temporal resolution along with exquisite tissue contrast. Previous studies have correlated myocardial scar tissue with the occurrence of ventricular arrhythmia. This study was conducted to evaluate whether characterization of myocardial infarction by CMR can predict cardiovascular events in patients with ischemic cardiomyopathy (ICM). Results: We consecutively studied 86 patients with ICM (LVEF < 50%, mean LVEF: 26 ± 12%) with CMR before revascularization or medication therapy ± implantable cardiac defibrillator, determined the amount of myocardial scar, and followed for development of cardiovascular events. Thirty-three patients (38%) had cardiovascular events (mean follow-up: 20 ± 16 months). Patients who developed cardiovascular events had larger scar volume and scar percentage of the myocardium than those who did not develop cardiovascular events (16.8 ± 12.4 cm3 vs. 11.7 ± 12.6 cm3, p = 0.023 and 10.2 ± 6.9% vs. 7.2 ± 6.7%, p = 0.037, respectively). There were no significant differences in LVEDV, LVESV and LVEF between the patients with and without cardiovascular events (231 ± 76 ml vs. 230 ± 88 ml; 180 ± 73 ml vs. 175 ± 90 ml; and 25 ± 10% vs. 27 ± 13%, respectively). Conclusion: Quantification of the scar volume and scar percentage by CMR is superior to LVEDV, LVESV, and LVEF in prognosticating the future likelihood of the development of cardiovascular events in patients with ICM.

Relation between myocardial edema and myocardial mass during the acute and convalescent phase of myocarditis - a CMR study

2008-04-30

Background: Myocardial edema is a substantial feature of the inflammatory response in human myocarditis. The relation between myocardial edema and myocardial mass in the course of healing myocarditis has not been systematically investigated. We hypothesised that the resolution of myocardial edema as visualised by T2-weighted cardiovascular magnetic resonance (CMR) is associated with a decrease of myocardial mass in steady state free precession (SSFP)-cine imaging. Methods: 21 patients with acute myocarditis underwent CMR shortly after onset of symptoms and 1 year later. For visualization of edema, a T2-weighted breath-hold black-blood triple-inversion fast spin echo technique was applied and the ratio of signal intensity of myocardium/skeletal muscle was assessed. Left ventricular (LV) mass, volumes and function were quantified from biplane cine steady state free precession images. 11 healthy volunteers served as a control group for interstudy reproducibility of LV mass. Results: In patients with myocarditis, a significant decrease in LV mass was observed during follow-up compared to the acute phase (156.7+/-30.6 g vs. 140.3+/-28.3 g, p<0.0001). The reduction of LV mass paralleled the normalization of initially increased myocardial signal intensity on T2-weighted images (2.4+/-0.4 vs. 1.68+/-0.3, p<0.0001). In controls, the interstudy difference of LV mass was lower than in patients (5.1+/-2.9 g vs. 16.3+/-14.2 g, p=0.02) resulting in a lower coefficient of variability (2.1 vs 8.9%, p=0.04). Conclusion: Reversible abnormalities in T2-weighted CMR are paralleled by a transient increase in left ventricular mass during the course of myocarditis. Myocardial edema may be a common pathway explaining these findings.

Late Gadolinium Enhancement of the right ventricular myocardium: Is it really different from the left?

Lars Grosse-Wortmann, Christopher K Macgowan, Logi Vidarsson and Shi-Joon Yoo — 2008-05-08

It has been suggested that, in late gadolinium enhancement, the signal of right ventricular myocardium is nulled at a shorter inversion time than the left. While we initially made the same observation, we believe that the difference is not real, but results from artifacts. We present 7 cases as well as computer simulations to describe the nature of these artifacts and explain how they can create the impression of different inversion times for the right and left ventricle. At inversion times that are shorter than ideal for the myocardium a black rim can be seen at the border of the myocardium with blood on the inside and with fat on the outside. This is most likely a partial volume effect. The thin myocardium of the right ventricle is sandwiched between these black rims and, at a low spatial resolution, is no longer visible. In this case, the adjacent black rims may then be misinterpreted as myocardium. While black rims also occur on the left side, the myocardium is thicker and remains discernable as a separate layer. As a consequence, the optimal inversion time for the right ventricle only appears different from that for the left. In fact, in the presence of hypertrophy of the right ventricle or during systolic wall thickening we did not find a difference in inversion times between the left and right ventricle. We conclude that sufficient spatial resolution is important for adequate late gadolinium enhancement of the right ventricle.

Mapping of mitral regurgitant defects by cardiovascular magnetic resonance in moderate or severe mitral regurgitation secondary to mitral valve prolapse

2008-04-09

PurposeIn mitral valve prolapse, determining whether the valve is suitable for surgical repair depends on the location and mechanism of regurgitation. We assessed whether cardiovascular magnetic resonance (CMR) could accurately identify prolapsing or flail mitral valve leaflets and regurgitant jet direction in patients with known moderate or severe mitral regurgitation. Methods: CMR of the mitral valve was compared with trans-thoracic echocardiography (TTE) in 27 patients with chronic moderate to severe mitral regurgitation due to mitral valve prolapse. Contiguous long-axis high temporal resolution CMR cines perpendicular to the valve commissures were obtained across the mitral valve from the medial to lateral annulus. This technique allowed systematic valve inspection and mapping of leaflet prolapse using a 6 segment model. CMR mapping was compared with trans-oesophageal echocardiography (TOE) or surgical inspection in 10 patients. Results: CMR and TTE agreed on the presence/absence of leaflet abnormality in 53 of 54 (98%) leaflets. Prolapse or flail was seen in 36 of 54 mitral valve leaflets examined on TTE. CMR and TTE agreed on the discrimination of prolapse from flail in 33 of 36 (92%) leaflets and on the predominant regurgitant jet direction in 26 of the 27 (96%) patients. In the 10 patients with TOE or surgical operative findings available, CMR correctly classified presence/absence of segmental abnormality in 49 of 60 (82%) leaflet segments. Conclusion: Systematic mitral valve assessment using a simple protocol is feasible and could easily be incorporated into CMR studies in patients with mitral regurgitation due to mitral valve prolapse.

Time course of eosinophilic myocarditis visualized by CMR

2008-05-08

We report the diagnostic potential of cardiovascular magnetic resonance (CMR) to visualize the time course of eosinophilic myocarditis upon successful treatment. A 50-year-old man was admitted with a progressive heart failure. Endomyocardial biopsies were taken from the left ventricle because of a white blood cell count of 17000/mm^3 with 41 % eosinophils. Histological evaluation revealed endomyocardial eosinophilic infiltration and areas of myocyte necrosis. The patient was diagnosed with hypereosinophilic myocarditis due to idiopathic hypereosinophilic syndrome. CMR-studies at presentation and a follow-up study 3 weeks later showed diffuse subendocardial LGE in the whole left ventricle. Upon treatment with steroids, CMR-studies revealed marked reduction of subendocardial LGE after 3 months in parallel with further clinical improvement. This case therefore highlights the clinical importance of CMR to visualize the extent of endomyocardial involvement in the diagnosis and treatment of eosinophilic myocarditis.

Accuracy of electrocardiographic criteria for atrial enlargement: validation with cardiovascular magnetic resonance

2008-01-25

Background: Anatomic atrial enlargement is associated with significant morbidity and mortality. However, atrial enlargement may not correlate with clinical measures such as electrocardiographic (ECG) criteria. Past studies correlating ECG criteria with anatomic measures mainly used inferior M-mode or two-dimensional echocardiographic data. We sought to determine the accuracy of the ECG to predict anatomic atrial enlargement as determined by volumetric cardiovascular magnetic resonance (CMR). Methods: ECG criteria for left (LAE) and right atrial enlargement (RAE) were compared to CMR atrial volume index measurements for 275 consecutive subjects referred for CMR (67% males, 51 ± 14 years). ECG criteria for LAE and RAE were assessed by an expert observer blinded to CMR data. Atrial volume index was computed using the biplane area-length method. Results: The prevalence of CMR LAE and RAE was 28% and 11%, respectively, and by any ECG criteria was 82% and 5%, respectively. Though nonspecific, the presence of at least one ECG criteria for LAE was 90% sensitive for CMR LAE. The individual criteria P mitrale, P wave axis < 30°, and negative P terminal force in V1 (NPTF-V1) > 0.04s·mm were 88–99% specific although not sensitive for CMR LAE. ECG was insensitive but 96–100% specific for CMR RAE. Conclusion: The presence of at least one ECG criteria for LAE is sensitive but not specific for anatomic LAE. Individual criteria for LAE, including P mitrale, P wave axis < 30°, or NPTF-V1 > 0.04s·mm are highly specific, though not sensitive. ECG is highly specific but insensitive for RAE. Individual ECG P wave changes do not reliably both detect and predict anatomic atrial enlargement.

Imaging myocardial carcinoid with T2-STIR CMR

William A Schiavone, Christopher Baker and Sanjay K Prasad — 2008-03-19

We used T2-STIR (Short Tau Inversion Recovery) cardiovascular magnetic resonance to demonstrate carcinoid tumor metastases to the heart and liver in a 64-year-old woman with a biopsy-proven ileal carcinoid tumor who was referred because of an abnormal echocardiogram.

Combined chelation therapy in thalassemia major for the treatment of severe myocardial siderosis with left ventricular dysfunction

2008-02-25

Background: In thalassemia major (TM), severe cardiac siderosis can be treated by continuous parenteral deferoxamine, but poor compliance, complications and deaths occur. Combined chelation therapy with deferiprone and deferoxamine is effective for moderate myocardial siderosis, but has not been prospectively examined in severe myocardial siderosis. Methods: T2* cardiovascular magnetic resonance (CMR) was performed in 167 TM patients receiving standard subcutaneous deferoxamine monotherapy, and 22 had severe myocardial siderosis (T2* < 8 ms) with impaired left ventricular (LV) function. Fifteen of these patients received combination therapy with subcutaneous deferoxamine and oral deferiprone with CMR follow-up. Results: At baseline, deferoxamine was prescribed at 38 ± 10.2 mg/kg for 5.3 days/week, and deferiprone at 73.9 ± 4.0 mg/kg/day. All patients continued both deferiprone and deferoxamine for 12 months. There were no deaths or new cardiovascular complications. The myocardial T2* improved (5.7 ± 0.98 ms to 7.9 ± 2.47 ms; p = 0.010), with concomitant improvement in LV ejection fraction (51.2 ± 10.9% to 65.6 ± 6.7%; p < 0.001). Serum ferritin improved from 2057 (CV 7.6%) to 666 (CV 13.2%) μg/L (p < 0.001), and liver iron improved (liver T2*: 3.7 ± 2.9 ms to 10.8 ± 7.3 ms; p = 0.006). Conclusion: In patients with severe myocardial siderosis and impaired LV function, combined chelation therapy with subcutaneous deferoxamine and oral deferiprone reduces myocardial iron and improves cardiac function. This treatment is considerably less onerous for the patient than conventional high dose continuous subcutaneous or intravenous deferoxamine monotherapy, and may be considered as an alternative. Very prolonged tailored treatment with iron chelation is necessary to clear myocardial iron, and alterations in chelation must be guided by repeated myocardial T2* scans.Trial registrationThis trial is registered as NCT00103753

Anomalous origin of the left circumflex coronary artery from the pulmonary artery. A very rare congenital anomaly in an adult patient diagnosed by cardiovascular magnetic resonance

Grigorios Korosoglou, Gerd Ringwald, Evangelos Giannitsis and Hugo A Katus — 2008-01-21

Here we report for the first time on the diagnostic potential of cardiovascular magnetic resonance (CMR) to delineate the proximal course of an anomalous left circumflex coronary artery (LCX) originating from the right pulmonary artery in an adult patient with no other form of congenital heart disease. The patient was referred to our institution due to exertional chest discomfort. X-Ray coronary angiography showed a normal left anterior descending coronary artery (LAD) and right coronary artery (RCA), while the LCX was filled retrograde by collateral flow through the LAD and the RCA. The origin of the LCX was postulated to be the pulmonary artery, but the exact origin of the anomalous artery could not be depicted on conventional angiograms. CMR provided the unambiguous depiction of the origin of the anomalous LCX from the right pulmonary artery and the delineation of its proximal course in this case of a very rare coronary anomaly in adults.