Right ventricular thrombus, a challenge in imaging diagnostics: a case series.

BACKGROUND: Presence of right ventricular thrombus (RVT) is a rare but life-threatening condition, thus immediate diagnosis and therapy are mandatory. Unfortunately, detection and distinction from intraventricular tumour masses or vegetations represent a complex task. Furthermore, consecutive therapy is principally led by clinical presentation without considering morphological features of the thrombus. Current literature suggests a multimodal non-invasive imaging approach. In this article, we discuss the role of cardiac magnetic resonance imaging (CMR) for the detection of RVT in patients with pulmonary embolism (PE). We consider the relatively expensive and not broadly available imaging procedure and weigh it up to its assumed high sensitivity, specificity, and importance for differential diagnosis and therapeutic decision-making. CASE SUMMARY: In this case series, we report three cases of RVT with concomitant PE, whereof two were missed during routine cardiac workup by transthoracic echocardiography and computer tomography. Cardiac magnetic resonance imaging led to detection and further characterization of the thrombi in both cases. CONCLUSIONS: Cardiac magnetic resonance imaging reliably detects and characterizes RVT, even under unfavourable conditions for echocardiography such as arrhythmia, adiposity, or in posterior position of RVT. Obtained information could facilitate the choice of therapeutic approach (anticoagulation vs. systemic lysis vs. surgical thrombectomy). Future risk stratification scores will promote cost-effective use of CMR.

Cardiac Magnetic Resonance Reveals Incipient Cardiomyopathy Traits in Adult Patients With Phenylketonuria.

Background Phenylketonuria is the most common inborn error of amino acid metabolism, where oxidative stress and collateral metabolic abnormalities are likely to cause cardiac structural and functional modifications. We aim herein to characterize the cardiac phenotype of adult subjects with phenylketonuria using advanced cardiac imaging. Methods and Results Thirty-nine adult patients with phenylketonuria (age, 30.5±8.7 years; 10-year mean phenylalanine concentration, 924±330 µmol/L) and 39 age- and sex-matched healthy controls were investigated. Participants underwent a comprehensive cardiac magnetic resonance and echocardiography examination. Ten-year mean plasma levels of phenylalanine and tyrosine were used to quantify disease activity and adherence to treatment. Patients with phenylketonuria had thinner left ventricular walls (septal end-diastolic thickness, 7.0±17 versus 8.8±1.7 mm [P<0.001]; lateral thickness, 6.1±1.4 versus 6.8±1.2 mm [P=0.004]), more dilated left ventricular cavity (end-diastolic volume, 87±14 versus 80±14 mL/m2 [P=0.0178]; end-systolic volume, 36±9 versus 29±8 mL/m2 [P<0.001]), lower ejection fraction (59±6% versus 64±6% [P<0.001]), reduced systolic deformation (global circumferential strain, -29.9±4.2 % versus -32.2±5.0 % [P=0.027]), and lower left ventricular mass (38.2±7.9 versus 47.8±11.0 g/m2 [P<0.001]). T1 native values were decreased (936±53 versus 996±26 ms [P<0.001]), with particular low values in patients with phenylalanine >1200 µmol/L (909±48 ms). Both mean phenylalanine (P=0.013) and tyrosine (P=0.035) levels were independently correlated with T1; and in a multiple regression model, higher phenylalanine levels and higher left ventricular mass associate with lower T1. Conclusions Cardiac phenotype of adult patients with phenylketonuria reveals some traits of an early-stage cardiomyopathy. Regular cardiology follow-up, tighter therapeutic control, and prophylaxis of cardiovascular risk factors, in particular dyslipidemia, are recommended.

Cardiac Myxomas Show Elevated Native T1, T2 Relaxation Time and ECV on Parametric CMR.

Introduction: While cardiac tumors are rare, their identification and differentiation has wide clinical implications. Recent cardiac magnetic resonance (CMR) parametric mapping techniques allow for quantitative tissue characterization. Our aim was to examine the range of values encountered in cardiac myxomas in correlation to histological measurements. Methods and Results: Nine patients with histologically proven cardiac myxomas were included. CMR (1.5 Tesla, Philips) including parametric mapping was performed in all patients pre-operatively. All data are reported as mean ± standard deviation. Compared to myocardium, cardiac myxomas demonstrated higher native T1 relaxation times (1,554 ± 192 ms vs. 1,017 ± 58 ms, p < 0.001), ECV (46.9 ± 13.0% vs. 27.1 ± 2.6%, p = 0.001), and T2 relaxation times (209 ± 120 ms vs. 52 ± 3 ms, p = 0.008). Areas with LGE showed higher ECV than areas without (54.3 ± 17.8% vs. 32.7 ± 18.6%, p = 0.042), with differences in native T1 relaxation times (1,644 ± 217 ms vs. 1,482 ± 351 ms, p = 0.291) and T2 relaxation times (356 ± 236 ms vs. 129 ± 68 ms, p = 0.155) not reaching statistical significance. Conclusions: Parametric CMR showed elevated native T1 and T2 relaxation times and ECV values in cardiac myxomas compared to normal myocardium, reflecting an increased interstitial space and fluid content. This might help in the differentiation of cardiac myxomas from other tumor entities.

Long-term left atrial remodeling after ablation of persistent atrial fibrillation: 7-year follow-up by cardiovascular magnetic resonance imaging.

PURPOSE: Restoration of sinus rhythm in patients with persistent atrial fibrillation (ps. AF) induces reverse atrial remodeling and improvement of left ventricular function. We evaluated the effect of ablative treatment on cardiac remodeling after a long follow-up period of 7 years by cardiovascular magnetic resonance (CMR). METHODS: Patients with symptomatic ps. AF underwent CMR within 7 days prior to the ablation procedure. Left atrial and ventricular volumes were measured. All patients underwent circumferential pulmonary vein isolation. At the end of follow-up (FU), a CMR and 7-day ECG registration were performed. RESULTS: Forty-two patients (67 ± 9 years) were included. After a FU of 86 ± 13 months, 23 patients had a successful outcome. In these patients, LVEF improved from 56 ± 5 to 62 ± 4% (p = 0.02), but left atrial volume and ejection fraction (LAV, LAEF) remained unchanged (105 ± 25 to 98 ± 34, p = 0.44; 34 ± 10 to 36 ± 11, p = 0.6, respectively). In 14 patients with a BMI < 30 and no left ventricular hypertrophy (LVH), LAV decreased (104 ± 30 to 82 ± 26 ml, p = 0.01) and LAEF improved (33 ± 12 to 40 ± 11%, p = 0.03). In 9 patients with successful outcome and either BMI ≥ 30 or LVH, LAV increased (110 ± 26 to 125 ± 30 ml, p = 0.03) and LAEF deteriorated (35 ± 11 to 31 ± 10%, p = 0.04). CONCLUSIONS: Successful ablative treatment of atrial fibrillation is associated with reverse left atrial remodeling and improvement of left atrial and ventricular function. In patients with a BMI ≥ 30 or left ventricular hypertrophy, further left atrial enlargement occurs despite successful outcome.

Case Report: Early Transplant Rejection of a Methanol-Intoxicated Donor Heart in a Young Female Patient. A Diagnostic Approach With CMR, Cardiac Biopsy, and Genetic Risk Assessment.

This case report describes the contributions of multimodality imaging, cardiac biopsy, and genetic sequencing to the diagnosis and management of heart transplant rejection in a 23-year old patient with dilated cardiomyopathy.

Fatty metaplasia quantification and impact on regional myocardial function as assessed by advanced cardiac MR imaging.

OBJECTIVE: This study aimed to investigate the advantages of recently developed cardiac imaging techniques of fat-water separation and feature tracking to characterize better individuals with chronic myocardial infarction (MI). MATERIALS AND METHODS: Twenty patients who had a previous MI underwent CMR imaging. The study protocol included routine cine and late gadolinium enhancement (LGE) technique. In addition, mDixon LGE imaging was performed in every patient. Left ventricular (LV) circumferential (EccLV) and radial (ErrLV) strain were calculated using dedicated software (CMR42, Circle, Calgary, Canada). The extent of global scar was measured in LGE and fat-water separated images to compare conventional and recent CMR imaging techniques. RESULTS: The infarct size derived from conventional LGE and fat-water separated images was similar. However, detection of lipomatous metaplasia was only possible with mDixon imaging. Subjects with fat deposition demonstrated a significantly smaller percentage of fibrosis than those without fat (10.68 ± 5.07% vs. 13.83 ± 6.30%; p = 0.005). There was no significant difference in EccLV or ErrLV between myocardial segments containing fibrosis only and fibrosis with fat. However, EccLV and ErrLV values were significantly higher in myocardial segments adjacent to fibrosis with fat deposition than in those adjacent to LGE only. CONCLUSIONS: Advanced CMR imaging ensures more detailed tissue characterization in patients with chronic MI without a relevant increase in imaging and post-processing time. Fatty metaplasia may influence regional myocardial deformation especially in the myocardial segments adjacent to scar tissue. A simplified and shortened myocardial viability CMR protocol might be useful to better characterize and stratify patients with chronic MI.

Multi-centre study of whole-heart dynamic 3D cardiac magnetic resonance perfusion imaging for the detection of coronary artery disease defined by fractional flow reserve: gender based analysis of diagnostic performance.

AIMS: Coronary artery disease (CAD) is a leading cause of morbidity and mortality in women and non-invasive testing for CAD in women can be more challenging than in men. This study compared the diagnostic performance of whole-heart dynamic 3D cardiovascular magnetic resonance (CMR) stress perfusion imaging in female and male patients with quantitative coronary angiography (QCA) and fractional flow reserve (FFR) as reference tests. METHODS AND RESULTS: Four hundred sixteen patients with suspected or known CAD were enrolled in five European centres. CMR imaging was performed prior to clinically indicated coronary angiography. QCA was performed in all patients and FFR in 357 of 416 patients. Whole-heart dynamic 3D CMR first-pass perfusion imaging was conducted at rest and during adenosine stress. All CMR analyses were operated by experienced investigators blinded to all clinical data. One hundred nineteen female and 297 male patients were included and successfully examined (mean age 65 ± 11 and 63 ± 11 years, respectively). FFR was performed in 106 female and 251 male patients. Sensitivity and specificity of whole-heart dynamic 3D CMR stress perfusion imaging were 89% (95% CI: 77-96) and 82% (95% CI: 70-90) in the female population and 83% (95% CI: 77-86) and 79% (95% CI: 71-86) in the male population relative to QCA (P = 0.474 and P = 0.83, P-values for comparison between genders). Sensitivity and specificity were 95% (95% CI: 82-99) and 84% (95% CI: 73-92) in the female population and 83% (95% CI: 76-89) and 82% (95% CI: 74-88) in the male population when using FFR as the reference (P = 0.134 and P = 0.936, P-values for comparison between genders). Diagnostic accuracy in females was 92% (95% CI: 85-96) and 86% (95% CI: 81-90) in males when using FFR as the reference. The prevalence of CAD as defined by FFR (<0.8) was 36% in females and 53% in males. CONCLUSION: Whole-heart dynamic 3D CMR stress perfusion imaging has a high diagnostic accuracy for the detection of significant CAD irrespective of gender and is therefore a suitable non-invasive testing tool to detect myocardial ischaemia in both genders.

Multicenter evaluation of dynamic three-dimensional magnetic resonance myocardial perfusion imaging for the detection of coronary artery disease defined by fractional flow reserve.

BACKGROUND: First-pass myocardial perfusion cardiovascular magnetic resonance (CMR) imaging yields high diagnostic accuracy for the detection of coronary artery disease (CAD). However, standard 2D multislice CMR perfusion techniques provide only limited cardiac coverage, and hence considerable assumptions are required to assess myocardial ischemic burden. The aim of this prospective study was to assess the diagnostic performance of 3D myocardial perfusion CMR to detect functionally relevant CAD with fractional flow reserve (FFR) as a reference standard in a multicenter setting. METHODS AND RESULTS: A total of 155 patients with suspected CAD listed for coronary angiography with FFR were prospectively enrolled from 5 European centers. 3D perfusion CMR was acquired on 3T MR systems from a single vendor under adenosine stress and at rest. All CMR perfusion analyses were performed in a central laboratory and blinded to all clinical data. One hundred fifty patients were successfully examined (mean age 62.9±10 years, 45 female). The prevalence of CAD defined by FFR (<0.8) was 56.7% (85 of 150 patients). The sensitivity and specificity of 3D perfusion CMR were 84.7% and 90.8% relative to the FFR reference. Comparison to quantitative coronary angiography (≥50%) yielded a prevalence of 65.3%, sensitivity and specificity of 76.5% and 94.2%, respectively. CONCLUSIONS: In this multicenter study, 3D myocardial perfusion CMR proved highly diagnostic for the detection of significant CAD as defined by FFR.

Cardiovascular magnetic resonance profiling of coronary atherosclerosis: vessel wall remodelling and related myocardial blood flow alterations.

AIMS: To determine the association between coronary vessel wall morphology and haemodynamic consequences to the myocardium using a combined cardiovascular magnetic resonance (CMR) imaging protocol. Non-invasive CMR profiling of coronary atherosclerotic wall changes and related myocardial blood flow impairment has not been established yet. METHODS AND RESULTS: Sixty-three patients (45 men, 61.5 ± 10.7 years) with suspected or known coronary artery disease underwent 3.0 Tesla CMR imaging. The combined CMR protocol consisted of the following imaging modules at rest: 3D vessel wall imaging and flow measurement of the proximal right coronary artery (RCA), myocardial T2*, and first-pass perfusion imaging. During adenosine stress coronary flow, T2* and first-pass perfusion imaging were repeated. Coronary X-ray angiography classified patient groups: (i) all-smooth (n = 19); (ii) luminal irregular (diameter reduction < 30%; n = 35); and (iii) stenosed RCA (diameter reduction ≥ 50%; n = 9). The ratio of CMR-derived vessel wall area-to-lumen area significantly increased stepwise for the comparison of all-smooth vs. luminal irregular vs. stenosed RCA (1.9 ± 0.6 vs. 2.6 ± 0.6 vs. 3.6 ± 0.9, P < 0.01). Epicardial coronary flow reserve exhibited a stepwise significant decrease (3.4 ± 0.5 vs. 2.9 ± 0.7 vs. 1.7 ± 0.3, P < 0.01). On the myocardial level, stress-induced percentage gain of T2* values (ΔT2*) was significantly decreased between groups (29.2 ± 10.6 vs. 9.0 ± 9.8 vs. 2.2 ± 11.8%, P < 0.01) while perfusion reserve index decreased in the presence of stenosed RCA only (2.2 ± 0.6 vs. 2.0 ± 0.4 vs. 1.3 ± 0.3, P = ns and P < 0.01, respectively). CONCLUSION: The proposed comprehensive CMR imaging protocol provided a non-invasive approach for direct assessment of coronary vessel wall remodelling and resultant pathophysiological consequences on the level of epicardial coronary and myocardial blood flow in patients.

Autologous CD133+ bone marrow cells and bypass grafting for regeneration of ischaemic myocardium: the Cardio133 trial.

AIMS: Intra-myocardial transplantation of CD133(+) bone marrow stem cells (BMC) yielded promising results in clinical pilot trials. We now performed the double-blinded, randomized, placebo-controlled CARDIO133 trial to determine its impact on left ventricular (LV) function and clinical symptoms. METHODS AND RESULTS: Sixty patients with chronic ischaemic heart disease and impaired LV function (left ventricular ejection fraction, LVEF <35%) were randomized to undergo either coronary artery bypass grafting (CABG) and injection of CD133(+) BMC in the non-transmural, hypokinetic infarct border zone (CD133), or CABG and placebo injection (placebo). Pre-operative LVEF was 27 ± 6% in CD133 patients and 26 ± 6% in placebo patients. Outcome was assessed after 6 months, and the primary endpoint was LVEF measured by cardiac magnetic resonance imaging (MRI) at rest. The incidence of adverse events was similar in both groups. There was no difference in 6-min walking distance, Minnesota Living with Heart Failure score, or Canadian Cardiovascular Society (CCS) class between groups at follow-up, and New York Heart Association class improved more in the placebo group (P = 0.004). By cardiac MRI, LVEF at 6 months was 33 ± 8% in the placebo group and 31 ± 7% in verum patients (P = 0.3), with an average inter-group difference of -2.1% (95% CI -6.3 to 2.1). Systolic or diastolic LV dimensions at 6 months were not different, either. In the CD133 group, myocardial perfusion at rest recovered in more LV segments than in the placebo group (9 vs. 2%, P < 0.001). Scar mass decreased by 2.2 ± 5 g in CD133(+) patients (P = 0.05), but was unchanged in the placebo group (0.3 ± 4 g, P = 0.7; inter-group difference in change = 2 g (95% CI -1.1 to 5)). By speckle-tracking echocardiography, cell-treated patients showed a better recovery of regional wall motion when the target area was posterior. CONCLUSION: Although there may be some improvements in scar size and regional perfusion, intra-myocardial injection of CD133(+) BMC has no effect on global LV function and clinical symptoms. Improvements in regional myocardial function are only detectable in patients with posterior infarction, probably because the interventricular septum after anterior infarction is not accessible by trans-epicardial injection. CLINICAL TRIAL REGISTRATION: This trial was registered at http://www.clinicaltrials.gov under NCT00462774.

Delayed contrast-enhanced MRI of the coronary artery wall in takayasu arteritis.

BACKGROUND: Takayasu arteritis (TA) is a rare form of chronic inflammatory granulomatous arteritis of the aorta and its major branches. Late gadolinium enhancement (LGE) with magnetic resonance imaging (MRI) has demonstrated its value for the detection of vessel wall alterations in TA. The aim of this study was to assess LGE of the coronary artery wall in patients with TA compared to patients with stable CAD. METHODS: We enrolled 9 patients (8 female, average age 46±13 years) with proven TA. In the CAD group 9 patients participated (8 male, average age 65±10 years). Studies were performed on a commercial 3T whole-body MR imaging system (Achieva; Philips, Best, The Netherlands) using a 3D inversion prepared navigator gated spoiled gradient-echo sequence, which was repeated 34-45 minutes after low-dose gadolinium administration. RESULTS: No coronary vessel wall enhancement was observed prior to contrast in either group. Post contrast, coronary LGE on IR scans was detected in 28 of 50 segments (56%) seen on T2-Prep scans in TA and in 25 of 57 segments (44%) in CAD patients. LGE quantitative assessment of coronary artery vessel wall CNR post contrast revealed no significant differences between the two groups (CNR in TA: 6.0±2.4 and 7.3±2.5 in CAD; p = 0.474). CONCLUSION: Our findings suggest that LGE of the coronary artery wall seems to be common in patients with TA and similarly pronounced as in CAD patients. The observed coronary LGE seems to be rather unspecific, and differentiation between coronary vessel wall fibrosis and inflammation still remains unclear.

Gender-based prognostic value of pharmacological cardiac magnetic resonance stress testing: head-to-head comparison of adenosine perfusion and dobutamine wall motion imaging.

This study evaluated the gender related long-term prognostic value of adenosine perfusion and dobutamine wall motion imaging as assessed during a combined single-session stress cardiac magnetic resonance (CMR) examination. In 717 patients a combined CMR stress examination was performed. Inducible perfusion deficits and wall motion abnormalities were identified visually. Clinical parameters were assessed at the time of the CMR examination. All patients were contacted to determine the occurrence of hard cardiac events (cardiac death, myocardial infarction) during a median follow-up period of 5.3 years. A complete combined CMR examination and follow-up data were available in 679 patients (471 men). A total of 77 hard cardiac events (63 in men) occurred during follow-up. Multivariate analysis revealed the presence of inducible perfusion deficits or wall motion abnormalities as independent predictors of hard cardiac events for both gender with an incremental value over conventional cardiovascular risk factors. In case of a negative stress test result, event-free survival was 100% in women for 4 years and >99% in men for 2 years after the CMR examination. CMR perfusion and wall motion testing are equally suited for cardiac risk stratification in men and women. Stress CMR negative women exhibited very low event rates up to 4 years following the examination, while in men annual event rates increased after the second year. Consequently, the generally proposed 2-year warranty period of non-invasive stress testing may be prolonged to a 4 year level in CMR stress testing negative women.

Dynamic 3-dimensional stress cardiac magnetic resonance perfusion imaging: detection of coronary artery disease and volumetry of myocardial hypoenhancement before and after coronary stenting.

OBJECTIVES: The aim of this study was to establish a new, dynamic 3-dimensional cardiac magnetic resonance (3D-CMR) perfusion scan technique exploiting data correlation in k-space and time with sensitivity-encoding and to determine its value for the detection of coronary artery disease (CAD) and volumetry of myocardial hypoenhancement (VOLUME(hypo)) before and after percutaneous coronary stenting. BACKGROUND: Dynamic 3D-CMR perfusion imaging might improve detection of myocardial perfusion deficits and could facilitate direct volumetry of myocardial hypoenhancement. METHODS: In 146 patients with known or suspected CAD, a 3.0-T CMR examination was performed including cine imaging, 3D-CMR perfusion under adenosine stress and at rest followed by delayed enhancement imaging. Quantitative invasive coronary angiography defined significant CAD (≥ 50% luminal narrowing). Forty-eight patients underwent an identical repeat CMR examination after percutaneous stenting of at least 1 coronary lesion. The 3D-CMR perfusion scans were visually classified as pathologic if ≥ 1 segment showed an inducible perfusion deficit in the absence of delayed enhancement. The VOLUME(hypo) was measured by segmentation of the area of inducible hypoenhancement and normalized to left-ventricular myocardial volume (%VOLUME(hypo)). RESULTS: The 3D-CMR perfusion resulted in a sensitivity, specificity, and diagnostic accuracy of 91.7%, 74.3%, and 82.9%, respectively. Before and after coronary stenting, %VOLUME(hypo) averaged to 14.2 ± 9.5% and 3.2 ± 5.2%, respectively, with a relative VOLUME(hypo) reduction of 79.4 ± 25.4%. Intrareader and inter-reader reproducibility of VOLUME(hypo) measurements was high (Lin's concordance correlation coefficient, 0.96 and 0.96, respectively). CONCLUSIONS: The 3D-CMR stress perfusion provided high image quality and high diagnostic accuracy for the detection of significant CAD. The VOLUME(hypo) measurements were highly reproducible and allowed for the assessment of the treatment effect achievable by percutaneous coronary stenting.

Head-to-head comparison of first-pass MR perfusion imaging during adenosine and high-dose dobutamine/atropine stress.

To directly compare the stressor capabilities of adenosine and high-dose dobutamine/atropine using first pass myocardial perfusion magnetic resonance imaging. Fourty-one patients with suspected or known coronary artery disease underwent cardiac magnetic resonance (CMR) perfusion imaging at 1.5 Tesla on two consecutive days prior to invasive coronary angiography. On day 1 a standard CMR perfusion protocol during adenosine stress was carried out (adenosine infusion with 140 µg/kg/min, 0.1 mmol/kg Gd-DTPA). On day 2, the identical CMR perfusion sequence was repeated during a standard high-dose dobutamine/atropine stress protocol at rest and during target heart rate (85% of maximum age-predicted heart rate). Stress-inducible perfusion deficits were evaluated visually regarding presence and transmural extent. Quantitative coronary angiography served as the reference standard with significant stenosis defined as ≥50% luminal diameter reduction. Twenty-five patients (61%) had significant coronary stenoses. Adenosine and dobutamine stress CMR perfusion imaging resulted in an equally high sensitivity and specificity for the stenosis detection on a per patient basis (92 and 75% for both stressors, respectively). Agreement of both stressors with regard to the presence or absence of stress-inducible perfusion deficits was nearly perfect using patient- and segment based analysis (kappa 1.0 and 0.92, respectively). Adenosine and dobutamine/atropine stress CMR perfusion imaging are equally capable to identify stress inducible deficits and resulted in an almost identical extent of ischemic reactions. Though adenosine stress CMR perfusion imaging is widely employed, dobutamine stress CMR perfusion represents a valid alternative and may be particularly useful in patients with contraindications to vasodilator testing.

BOLD cardiovascular magnetic resonance at 3.0 tesla in myocardial ischemia.

BACKGROUND: The purpose of this study was to determine the ability of blood oxygen level dependent (BOLD) cardiovascular magnetic resonance (CMR) to detect stress-inducible myocardial ischemic reactions in the presence of angiographically significant coronary artery disease (CAD). METHODS: Forty-six patients (34 men; age 65 ± 9 years,) with suspected or known coronary artery disease underwent CMR at 3Tesla prior to clinically indicated invasive coronary angiography. BOLD CMR was performed in 3 short axis slices of the heart at rest and during adenosine stress (140 µg/kg/min) followed by late gadolinium enhancement (LGE) imaging. In all 16 standard myocardial segments, T2* values were derived at rest and under adenosine stress. Quantitative coronary angiography served as the standard of reference and defined normal myocardial segments (i.e. all 16 segments in patients without any CAD), ischemic segments (i.e. supplied by a coronary artery with ≥50% luminal narrowing) and non-ischemic segments (i.e. supplied by a non-significantly stenosed coronary artery in patients with significant CAD). RESULTS: Coronary angiography demonstrated significant CAD in 23 patients. BOLD CMR at rest revealed significantly lower T2* values for ischemic segments (26.7 ± 11.6 ms) compared to normal (31.9 ± 11.9 ms; p < 0.0001) and non-ischemic segments (31.2 ± 12.2 ms; p = 0.0003). Under adenosine stress T2* values increased significantly in normal segments only (37.2 ± 14.7 ms; p < 0.0001). CONCLUSIONS: Rest and stress BOLD CMR at 3Tesla proved feasible and differentiated between ischemic, non-ischemic, and normal myocardial segments in a clinical patient population. BOLD CMR during vasodilator stress identified patients with significant CAD.

Navigator-gated 3D blood oxygen level-dependent CMR at 3.0-T for detection of stress-induced myocardial ischemic reactions.

OBJECTIVES: This study determined the value of navigator-gated 3-dimensional blood oxygen level-dependent (BOLD) cardiac magnetic resonance (CMR) at 3.0-T for the detection of stress-induced myocardial ischemic reactions. BACKGROUND: Although BOLD CMR has been introduced for characterization of myocardial oxygenation status, previously reported CMR approaches suffered from a low signal-to-noise ratio and motion-related artifacts with impaired image quality and a limited diagnostic value in initial patient studies. METHODS: Fifty patients with suspected or known coronary artery disease underwent CMR at 3.0-T followed by invasive X-ray angiography within 48 h. Three-dimensional BOLD images were acquired during free breathing with full coverage of the left ventricle in a short-axis orientation. The BOLD imaging was performed at rest and under adenosine stress, followed by stress and rest first-pass perfusion and delayed enhancement imaging. Quantitative coronary X-ray angiography (QCA) was used for coronary stenosis definition (diameter reduction > or =50%). The BOLD and first-pass perfusion images were semiquantitatively evaluated (for BOLD imaging, signal intensity differences between stress and rest [DeltaSI]; for perfusion imaging, myocardial perfusion reserve index [MPRI]). RESULTS: The image quality of BOLD CMR at rest and during adenosine stress was considered good to excellent in 90% and 84% of the patients, respectively. The DeltaSI measurements differed significantly between normal myocardium, myocardium supplied by a stenotic coronary artery, and infarcted myocardium (p < 0.001). The receiver-operator characteristic analysis identified a cutoff value of DeltaSI = 2.7% for the detection of coronary stenosis, resulting in a sensitivity and specificity of 85.0% and 80.5%, respectively. An MPRI cutoff value of 1.35 yielded a sensitivity and specificity of 89.5% and 85.8%, respectively. The DeltaSI significantly correlated with the degree of coronary stenosis (r = -0.65, p < 0.001). Additionally, DeltaSI and MPRI showed substantial agreement (kappa value 0.66). CONCLUSIONS: Navigator-gated 3-dimensional BOLD imaging at 3.0-T reliably detected stress-induced myocardial ischemic reactions and may be considered a valid alternative to first-pass exogenous contrast-enhancement studies.