Measurement of ventricular volumes and function: a comparison of gated PET and cardiovascular magnetic resonance.

The aim of this study was to compare cardiac volume and function assessment using PET with the reference technique of cardiovascular magnetic resonance (CMR). METHODS: Left ventricular (LV) and right ventricular (RV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fractions (EF) were measured in 9 patients using both CMR and PET with inhaled C(15)O. RESULTS: Correlation between the techniques was generally reasonable (r values ranged from 0.63 to 0.99). Best agreement was seen for ESV (LV and RV). With PET, there was a tendency to underestimate LV EF and EDV, and RV EDV and SV. Agreement was worst for LV SV. Percentage difference between CMR and PET measurements ranged from -2% to 15%; Bland-Altman limits of agreement ranged from 24% to 75%. CONCLUSION: Although small systematic differences exist, the agreement between PET and CMR suggests useful information regarding function, and volumes may be obtained from a standard PET protocol.     

Accuracy of a new method for semi-quantitative assessment of right ventricular ejection fraction by cardiovascular magnetic resonance: Right ventricular fractional diameter changes

Objective

Longitudinal shortening is traditionally considered the predominant part of global right ventricular (RV) systolic function. Less attention has been paid to transverse contraction. The aim of this study was to evaluate RV transverse motion by cardiovascular magnetic resonance (CMR) in a large cohort of patients and to assess its relationship with RV ejection fraction (RVEF).

Study design

We retrospectively analyzed the CMR scans of 300 patients referred to our center in 2010. RVEF was determined from short axis sequences using the volumetric method. Transverse parameters called RV fractional diameter changes were calculated after measuring RV diastolic and systolic diameters at basal and mid-level in short axis view (respectively FBDC and FMDC). We also measured the tricuspid annular plane systolic excursion (TAPSE) as a longitudinal reference.

Results

Our population was divided into 2 groups according to RVEF. 250 patients had a preserved RVEF (>40%) and 50 had a RV dysfunction (RVEF ≤40%). Transverse and longitudinal motions were significantly reduced in the group with RV dysfunction (p < .0001). After ROC analysis, areas under the curve for FBDC, FMDC and TAPSE, were respectively 0.79, 0.82 and 0.72, with the highest specificity and sensitivity respectively of 88% and 68% for FMDC (threshold at 20%) for predicting RV dysfunction. FMDC had an excellent negative predictive value of 93%.

Conclusion

RV fractional diameter changes, especially at the mid-level, appear to be accurate for semi-quantitative assessment of RV function by CMR. A cut-off of 20% for FMDC differentiates patients with a low (EF ≤ 40%) or a preserved RVEF.     

Right ventricular function in healed myocardial infarction in man. A cineangiographic assessment

To evaluate the frequency of right ventricular dysfunction following recovery from myocardial infarction (MI) and the relationship of segmental right ventricular (RV) wall motion abnormalities to left ventricular (LV) function or location of coronary arterial stenosis, biplane right and left ventricular cineangiograms were obtained in 100 consecutive patients (4 +/- 3 months post MI). Thirty (group A) had anterior MI and significant stenosis or obstruction of left anterior descending artery (LAD). The remaining 70 patients had inferior MI. They were divided into three groups according to the site of the main coronary stenosis or obstruction and corresponding LV akinesia: right coronary artery (RCA) proximal to the acute marginal artery (RMA), (group B: 32 patients), RCA distal to the RMA (group C: 18 patients), left circumflex artery (LCF), (group D: 18 patients). RV and LV end-diastolic volume index (EDV), end-systolic volume index (ESV), stroke volume (SV) and ejection fraction (EF) have been determined. RV segmental wall motion was assessed in RAO and LAO projection by determining the percentage of systolic shortening (+ delta R) along 11 hemiaxes. Mean axial shortening (delta R) of the RV inferior and free walls were considered. When compared with that in 10 normal subjects, RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV) were increased and RV ejection fraction (RVEF) was lower in patients with anterior or inferior MI. Inferior delta R exhibited comparable sequential changes in the three groups of inferior MI and similar LVEF alteration.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnostic accuracy and variability of three semi-quantitative methods for assessing right ventricular systolic function from cardiac MRI in patients with acquired heart disease

Objectives  

To evaluate the diagnostic accuracy and variability of 3 semi-quantitative (SQt) methods for assessing right ventricular (RV) systolic function from cardiac MRI in patients with acquired heart disease: tricuspid annular plane systolic excursion (TAPSE), RV fractional-shortening (RVFS) and RV fractional area change (RVFAC).     

Validation of SPECT equilibrium radionuclide angiographic right ventricular parameters by cardiac magnetic resonance imaging

BACKGROUND: Recent advances in the treatment of primary pulmonary hypertension (PPH), and in surgery to correct tetralogy of Fallot (TOF), have rekindled interest in evaluating right ventricular (RV) volume and ejection fraction (EF). The purpose of this investigation was to determine the accuracy of RV functional parameters assessed by single photon emission computed tomography (SPECT) equilibrium radionuclide angiography (ERNA). METHODS AND RESULTS: Twenty-eight patients with PPH (n = 15) or TOF (n = 13) (aged 28 +/- 14 years; 57% male) were analyzed by means of SPECT ERNA algorithms that automatically identified mid-RV tomographic planes, generated regions isolating the right ventricle from other structures, and presented RV-segmented regions as a cinematic display. RV EF and volumes were computed and compared with values obtained by magnetic resonance imaging (MRI). Mean values were not different between SPECT ERNA and MRI for RV EF, end-diastolic volume, and end-systolic volume (42% +/- 11% vs 41% +/- 10%, 135 +/- 67 mL vs 139 +/- 91 mL, and 87 +/- 54 mL vs 85 +/- 61 mL, respectively; P = not significant for all comparisons). Significant linear correlation (P <.0001) was found between SPECT ERNA and MRI for RV EF, end-diastolic volume, and end-systolic volume (r = 0.85, r = 0.94, and r = 0.93, respectively). No statistically significant trends or biases for RV EF were found. Intraobserver and interobserver comparisons demonstrated good reproducibility. As expected, RV volume was significantly higher and RV EF was significantly lower for patients with PPH and TOF than were values for individuals at low likelihood for coronary artery disease or other cardiac disease. CONCLUSIONS: SPECT ERNA provides accurate, reproducible assessment of RV volumes and EF and should prove useful in evaluating the magnitude of RV dysfunction in patients and in providing an objective means with which to assess the results of therapeutic interventions.     

Improved reproducibility of right ventricular volumes and function estimation from cardiac magnetic resonance images using level-set models.

This study aims to assess whether an alternative method, that is based on volumetric surface detection (VoSD) without tracing and is totally free of geometric assumptions, can improve the reproducibility of right ventricular (RV) volume quantification from cardiac magnetic resonance (CMR) images, in comparison with a conventional disk-area technique. In a sample of 23 patients, with wide variability of RV end-diastolic volume (EDV: 47-131 ml), end-systolic volume (ESV: 20-76 ml), and ejection fraction (EF: 29-73%), using the standard method (Argus, Siemens) as the reference, the VoSD method showed good agreement for EDV, ESV, and EF estimations (correlation coefficient: 0.91, 0.94, and 0.94; Bland-Altman biases: 1 ml, 1 ml, and 0%; limits of agreement: +/-16 ml, +/-11 ml, and +/-11%, respectively). An analysis of the reproducibility of the two methods showed lower intraobserver variability for the VoSD method than for the conventional method, as evidenced by the coefficient of variability (CoV) values (2-6% vs. 8-15%; P < 0.05). In addition, the VoSD method showed improved interobserver reproducibility (7-10% vs. 8-15%), but the difference was statistically significant only for EF estimation variability (8 vs. 15%, P < 0.05). In conclusion, the newly developed VoSD technique allows accurate measurements of RV volumes and function, and appears to be more reproducible than the conventional methodology.     

Rapid MR assessment of left ventricular systolic function after acute myocardial infarction using single breath-hold cine imaging with the temporal parallel acquisition technique (TPAT) and 4D guide-point modelling analysis of left ventricular function

We compared four-dimensional guide-point modelling left ventricular function analysis (4DVF) results of cine images in four short-axis and two long-axis slices acquired in a single breath-hold, obtained with the temporal parallel acquisition technique (TPAT), with standard left ventricular function (LVF) analysis results determined by the summation of discs method, in patients who had recently suffered myocardial infarction. Despite wall motion abnormalities, 4DVF yields results for left ventricular ejection fractions and end-diastolic and end-systolic volumes that are in excellent agreement with standard LVF analysis results in these patients. A shortened cardiac magnetic resonance (CMR) protocol using single breath-hold cine image acquisition could facilitate the assessment of left ventricular function soon after myocardial infarction in critically ill patients who are unable to comply with the multiple breath-holds required for standard LVF analysis.     

Successful coronary revascularization improves prognosis in patients with previous myocardial infarction and evidence of viable myocardium at thallium-201 imaging

The role of coronary revascularization of dysfunctional myocardium with preserved thallium-201 uptake in determining the prognosis in patients after myocardial infarction remains to be defined. This study was designed to evaluate the effects of successful revascularization on survival and left ventricular (LV) function in patients with previous myocardial infarction and evidence of dysfunctional but still viable myocardium at rest-redistribution ²⁰¹Tl imaging. Seventy-six consecutive patients with LV dysfunction related to previous myocardial infarction and evidence of viable myocardium at rest-redistribution ²⁰¹Tl tomography were followed for 17±8 months. LV ejection fraction (EF) was assessed by radionuclide angiography at baseline and after 13±2 months. Thirty-nine patients were revascularized (group A) and 37 treated medically (group B). During the follow-up there were nine cardiac deaths. Survival rate was 97% in group A and 66% in group B (P<0.01). By Cox multivariate analysis, the extent of viable myocardium was the best predictor of cardiac death (χ²=8.67, P<0.01) and provided additional information to clinical and functional data (P<0.01). The inclusion of revascularization as a variable improved the global χ² of the model from 14.1 to 21.9 (P<0.01). At follow-up, EF had improved by ≥5% in 16 patients. By multivariate logistic analysis, the extent of viable myocardium was the best predictor of EF improvement (χ²=15.49, P<0.001) and provided additional information to clinical and functional data (P<0.01). The inclusion of revascularization as a variable improved the global χ² of the model from 16.8 to 22.5 (P<0.01). These results demonstrate that the total extent of dysfunctional myocardium with preserved ²⁰¹Tl uptake is the strongest predictor of cardiac death in patients after myocardial infarction. Successful revascularization of dysfunctional but viable myocardium improves survival and LVEF in such patients. Received 22 June and in revised form 15 September 1997     

Advances in Myocardial Perfusion MR Imaging: Physiological Implications,the Importance of Quantitative Analysis,and Impact on Patient Care in Coronary Artery Disease

Stress myocardial perfusion imaging (MPI) is the preferred test in patients with intermediate-to-high clinical likelihood of coronary artery disease (CAD) and can be used as a gatekeeper to avoid unnecessary revascularization. Cardiac magnetic resonance (CMR) has a number of favorable characteristics, including: (1) high spatial resolution that can delineate subendocardial ischemia; (2) comprehensive assessment of morphology, global and regional cardiac functions, tissue characterization, and coronary artery stenosis; and (3) no radiation exposure to patients. According to meta-analysis studies, the diagnostic accuracy of perfusion CMR is comparable to positron emission tomography (PET) and perfusion CT, and is better than single-photon emission CT (SPECT) when fractional flow reserve (FFR) is used as a reference standard. In addition, stress CMR has an excellent prognostic value. One meta-analysis study demonstrated the annual event rate of cardiovascular death or non-fatal myocardial infarction was 4.9% and 0.8%, respectively, in patients with positive and negative stress CMR. Quantitative assessment of perfusion CMR not only allows the objective evaluation of regional ischemia but also provides insights into the pathophysiology of microvascular disease and diffuse subclinical atherosclerosis. For accurate quantification of myocardial perfusion, saturation correction of arterial input function is important. There are two major approaches for saturation correction, one is a dual-bolus method and the other is a dual-sequence method. Absolute quantitative mapping with myocardial perfusion CMR has good accuracy in detecting coronary microvascular dysfunction. Flow measurement in the coronary sinus (CS) with phase contrast cine CMR is an alternative approach to quantify global coronary flow reserve (CFR). The measurement of global CFR by quantitative analysis of perfusion CMR or flow measurement in the CS permits assessment of microvascular disease and diffuse subclinical atherosclerosis, which may provide improved prediction of future event risk in patients with suspected or known CAD. Multi-institutional studies to validate the diagnostic and prognostic values of quantitative perfusion CMR approaches are required.     

Strain‐encoded cardiac MR during high‐dose dobutamine stress testing: Comparison to cine imaging and to myocardial tagging

Purpose

To investigate regional strain response during high‐dose dobutamine stress cardiac magnetic resonance imaging (DS‐CMR) using myocardial tagging and Strain‐Encoded MR (SENC).

Materials and Methods

Stress induced ischemia was assessed by wall motion analysis, by tagged CMR and by SENC in 65 patients with suspected or known CAD who underwent DS‐CMR in a clinical 1.5 Tesla scanner. Coronary angiography deemed as the standard reference for the presence or absence of CAD (≥50% diameter stenosis) in all patients.

Results

SENC and conventional tagging detected abnormal strain response in six and five additional patients, respectively, who were missed by cine images and proved to have CAD by angiography (P < 0.05 for SENC versus cine, P = 0.06 for tagging versus cine and p = NS for SENC versus tagging). On a per‐vessel level, wall motion analysis on cine images showed high specificity (95%) but moderate sensitivity (70%) for the detection of CAD. Tagging and SENC yielded significantly higher sensitivity of 81% and 89%, respectively (P < 0.05 for tagging and P < 0.01 for SENC versus wall motion analysis, and p = NS for SENC versus tagging), while specificity was equally high (96% and 94%, respectively, P = NS for all).

Conclusion

Both the direct color‐coded visualization of strain on CMR images and the generation of additional visual markers within the myocardium with tagged CMR represent useful adjuncts for DS‐CMR, which may provide incremental value for the detection of CAD in humans. J. Magn. Reson. Imaging 2009;29:1053–1061. © 2009 Wiley‐Liss, Inc.     

Acute oedema in the evaluation of microvascular reperfusion and myocardial salvage in reperfused myocardial infarction with cardiac magnetic resonance imaging

The accurate measurement of myocardial salvage is critical to the ongoing refinement of reperfusion strategies in acute myocardial infarction (AMI). Cardiac magnetic resonance imaging (CMR) can define the area at risk in AMI by the presence of myocardial oedema, identified by high signal intensity on T₂-weighted imaging with a short inversion time inversion-recovery (STIR) sequence. In addition, myocardial necrosis can be identified with CMR delayed contrast enhanced imaging. In this prospective study we examined the relationship of acute oedema and necrosis with impaired microvascular reperfusion. We also evaluated acute oedema as a marker of the area at risk in AMI, for the purposes of documenting myocardial salvage. CMR was performed on 15 patients with (AMI), within 24 h of successful percutaneous coronary intervention (PCI). Left ventricular (LV) systolic dysfunction was defined by a systolic thickening <40% (severe <20%). Microvascular reperfusion was evaluated during the acute phase of contrast wash-in. CMR was repeated 3 months post-PCI to evaluate recovery of LV function and final infarct size. Myocardial salvage was defined as the percentage of the area at risk that was not infarcted on follow up CMR. There was a significant correlation between impaired microvascular reperfusion and the extent of segmental oedema (R = 0.363, P < 0.01), but not myocardial necrosis (R = 0.110, P > 0.5). The extent of myocardial salvage correlated with recovery of systolic function (R = 0.241, P < 0.05), which was strongest in LV segments with severely reduced systolic function (R = 0.422, P < 0.01). Conclusions: In acutely reperfused AMI, oedema can be used to identify the area at risk for the purpose of calculating myocardial salvage. The correlation between myocardial oedema and reperfusion status suggests a pathological role of acute oedema in the impairment of microvascular reperfusion.     

Accuracy of radionuclide ventriculography assessed by magnetic resonance imaging in patients with abnormal left ventricles

BACKGROUND: We compared gated blood pool single photon emission computed tomography (SPECT) (GBPS), planar gated blood pool imaging (planar GBP), and cardiac magnetic resonance (CMR) measurements of left ventricular (LV) end-diastolic volume (EDV) and ejection fraction (EF) in patients with abnormal left ventricles. METHODS AND RESULTS: LV functional parameters were measured for 40 subjects (age, 59 +/- 13 years; 85% male) by GBPS, planar GBP, and CMR. GBPS data were analyzed by use of count-threshold software (BP-SPECT) and surface gradient software (QBS). Limits of agreement with CMR for EF were -5% to +18%, -15% to +14%, and -15% to +16% for BP-SPECT, QBS, and planar GBP, respectively. However, limits of agreement with CMR for LV EDV were wide by both GBPS methods: -118 mL to +55 mL and -143 mL to +22 mL for BP-SPECT and QBS, respectively. Bland-Altman reproducibility limits for EF were -9% to +8%, -6% to +9%, and -7% to +7% by BP-SPECT, QBS, and planar GBP, respectively, and those for EDV were -46 mL to +48 mL and -31 mL to +35 mL by BP-SPECT and QBS, respectively. CONCLUSION: GBPS LV EF measurements agree with measurements by CMR and are as reproducible as planar GBP measurements. However, wide limits of agreement of radionuclide versus CMR values suggest that caution must be applied in interpreting GBPS LV volume results, especially for patients with markedly abnormal left ventricles.     

Four-dimensional single breathhold magnetic resonance imaging using kt-BLAST enables reliable assessment of left- and right-ventricular volumes and mass

PURPOSE: To prospectively determine the accuracy of four-dimensional (4D) kt-broad-use linear acquisition speed-up technique (BLAST) accelerated MRI (kt-BLAST) for the assessment of left-ventricular (LV) volumes and mass as well as right-ventricular (RV) volumes in comparison to standard multiple breathhold cine imaging. MATERIALS AND METHODS: A total of 40 patients with suspected or known coronary artery disease (CAD) underwent cardiac MRI. In each patient a standard multislice cine steady-state free precession (SSFP) sequence was performed with complete ventricular coverage during multiple breathholds. Additionally, a kt-BLAST-accelerated 4D sequence with complete ventricular coverage was acquired during one single breathhold. For comparison of SSFP and kt-BLAST, the following LV parameters were determined: end-diastolic and end-systolic volumes, ejection fraction, end-diastolic diameter and mass. For comparison of RV dimensions, end-diastolic and end-systolic volumes and ejection fraction were assessed. RESULTS: LV volumes, ejection fraction, diameter, and mass showed a strong correlation between SSFP and kt-BLAST (r=0.98-0.99; P<0.01). In addition, RV parameters demonstrated a high correlation (r=0.97-0.98; P<0.01). For all parameters, the calculated bias between both methods was found to be minimal (0.4-4%). CONCLUSION: 4D kt-BLAST-accelerated MRI enabled the accurate assessment of LV and RV quantitative parameters during one single breathhold when compared to standard multislice, multiple breathhold SSFP imaging.     

Stroke volume measurements with first-pass dynamic positron emission tomography: Comparison with cardiovascular magnetic resonance

Background  The assessment of forward stroke volume (SV) using dynamic, first-pass cardiac positron emission tomography (PET) was shown to be feasible in a limited number of studies with small numbers of subjects. The aim of this study was to compare first-pass derived SV with cardiovascular magnetic resonance imaging (CMR)-obtained values in a larger population of subjects. Methods and Results  Fifty-nine subjects with varying degrees of cardiac function were studied. Stroke volume was assessed using oxygen-15-labeled water (H₂ ¹⁵O) dynamic first-pass PET for both the right ventricle (RV) and left ventricle (LV), and compared with the findings of aorta velocity-encoded phase-contrast CMR. The PET-estimated SV was higher for the RV than for the LV (133±34 vs 116±31 mL, P<.01, ±SD), and both were higher compared with values obtained by CMR (81±20 mL, both P<.01,±SD). Although significant, the correlations between PET and CMR were moderate for both the RV (r=0.37, P<.01) and the LV (r=0.40, P<.01,±SD). Bland-Altman analysis revealed a progressive overestimation with increasing SV measured in either ventricle. Conclusions  First-pass dynamic H₂ ¹⁵O PET for the assessment of forward SV is feasible, although values are progressively overestimated with increasing SV, particularly when the RV is used, and correlations with aorta velocity-encoded phase-contrast CMR are moderate. These findings are probably protocol-dependent and warrant further study before the use of first-pass dynamic H₂ ¹⁵O PET in clinical or research settings can be advocated.     

Assessment of left ventricular deformation in patients with Ebstein’s anomaly by cardiac magnetic resonance tissue tracking

PurposeThe aim of this study was to clarify the feasibility of myocardial strain using cardiovascular magnetic resonance (CMR) for the evaluation of left ventricular (LV) deformation in patients with Ebstein’s anomaly (EA).Materials and methodsWe recruited 32 patients with EA and 30 controls for CMR examination and measured LV function, dimension and tissue tracking parameters (the global and regional radial, circumferential and longitudinal peak strain), together with the right ventricle (RV) dimension. LV strain parameters were compared among the controls, patients with preserved LV ejection fraction (LVEF; ≥55%), and patients with reduced LVEF (<55%). Pearson’s correlation was used to evaluate relationships between tissue tracking parameters with the RVEDD/LVEDD index and LVEF. An ROC analysis was also performed to determine whether the cut-off values for PS could be used to differentiate LV dysfunction between patients with EA and controls. The intraclass correlation coefficient (ICC) was used to assess the inter- and intra-observer variability.ResultsThe global strain parameters all decreased significantly in the EA group compared with the control group (all P < 0.05). Furthermore, the global radial and circumferential peak strain (PS) were obviously even lower in the reduced LVEF group than the strain measured in preserved LVEF groups (28.64% vs. 37.39%, p < 0.05; and −8.20% vs. −17.89%; p < 0.05; respectively). The regional strain abnormalities in EA patients were mainly involved in basal and middle segments. The results also demonstrated a significant correlation between the ratio of the RV end-diastolic dimension to the LV end-diastolic dimension (RVEDD/LVEDD index) with the global circumferential PS (r = 0.508) and the longitudinal PS (r = 0.474), as well as a good correlation between radial PS and LVEF (r = 0.465). The ICCs for intra- and inter-observer variability were 0.797–0.904 and 0.701–0.896.ConclusionsLV strain serves an earlier and more comprehensive measurement of LV dysfunction than LVEF in EA, which could potentially be included as a supplementary diagnostic procedure in the evaluation of EA.     

Evaluation of left ventricular wall motion, volumes, and ejection fraction by gated myocardial tomography with technetium 99m-labeled tetrofosmin: A comparison with cine magnetic resonance imaging

Background  Whether left ventricular function can be assessed accurately by gated single photon emission computed tomography (SPECT) in patients with myocardial infarction and severe perfusion defects is not well known. Methods and Results  Twenty-five patients with an acute myocardial infarction underwent ^99mTc-labeled tetrofosmin (^99mTc-tetrofosmin) gated SPECT and cine magnetic resonance imaging (MRI). Wall motion was assessed in 13 left ventricular segments using a 5-point scoring system ranging from 3 (normal) to-1 (dyskinetic). Exact agreement for wall motion scores between gated SPECT and MRI was excellent (92%, kappa=0.82). Furthermore, correlations between the two techniques were also good for end-diastolic volume (r=0.81, P<.0001), end-systolic volume (r=0.92, P<.0001), and ejection fraction (r=0.93, P<.0001). Conclusion  In patients with a recent myocardial infarction, ^99mTc-tetrofosmin gated SPECT provides reliable evaluation of global and regional ventricular function and volumes.     

Reproducibility of MRI measurements of right ventricular size and function in patients with normal and dilated ventricles

PURPOSE: To determine the inter- and intraobserver reproducibility of cardiac magnetic resonance (CMR)-derived measurements of right ventricular (RV) mass, volume, and function in patients with normal and dilated ventricles. MATERIALS AND METHODS: CMR studies of 60 patients in three groups were studied: a normal RV group (N = 20) and two groups with RV dilation-atrial septal defect (ASD) (N = 20) and repaired tetralogy of Fallot (TOF) (N = 20). Two independent observers analyzed each study on two separate occasions. Inter- and intraobserver reproducibility of biventricular mass, volume, ejection fraction (EF), and stroke volume (SV) measurements were calculated. RESULTS: High intraclass correlation coefficients (ICC) were found for interobserver (ICC = 0.94-0.99) and intraobserver (ICC = 0.96-0.99) comparisons of RV and left ventricular (LV) mass, volume, and SV measurements. RV and LV EF measurements were less reproducible (ICC = 0.79-0.87). RV mass measurements were significantly less correlated than the respective LV measurements. Small but statistically significant differences in correlation were noted in RV measurements across groups. CONCLUSION: Except for RV mass, inter- and intraobserver reproducibility of RV size and function measurements is high and generally comparable to that in the LV in patients with both normal and dilated RV.     

Evaluation of silent myocardial ischemia by exercise radionuclide ventriculography: comparison between patients with and without old myocardial infarction

We evaluated left ventricular systolic function during exercise in patients with silent or symptomatic myocardial ischemia by radionuclide ventriculography (RNV). The subjects consisted of 61 patients who had evidence of myocardial ischemia during exercise RNV defined as positive exercise electrocardiographic changes and angiographically documented coronary artery disease. The patients without angina during exercise (SMI) had less exercise-induced left ventricular systolic dysfunction than patients with angina (CP) (change in ejection fraction during exercise: delta EF; -1 +/- 13 vs -6 +/- 10%, p less than 0.05, systolic blood pressure/end-systolic volume in exercise divided by systolic blood pressure/end-systolic volume in rest: SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.8 +/- 0.3, p less than 0.05). The 61 patients were divided into two groups, that is, those with and without old myocardial infarction (OMI), and we compared the degree of left ventricular systolic dysfunction during exercise between SMI and CP by RNV in each group. In patients without OMI, SMI had less exercise-induced left ventricular dysfunction than CP (delta EF; 1 +/- 12 vs -10 +/- 8%, p less than 0.01, SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.7 +/- 0.2, p less than 0.01). However, there were no differences between SMI and CP with OMI. In conclusion, it was thought that SMI without OMI was less degree of myocardial ischemia, and that SMI with OMI was potentially caused by some factors except for the degree of myocardial ischemia.     

心脏MR纵向弛豫时间定量成像评估新型冠状病毒肺炎康复患者心肌损伤的价值

目的:探讨心脏MR（CMR）纵向弛豫时间定量成像（T 1 mapping）评估新型冠状病毒肺炎（COVID-19）康复者心肌损伤的价值。 方法:前瞻性收集阜阳市第二人民医院2020年5月至6月COVID-19患者康复出院3个月后接受CMR检查的15例患者（9例普通型、6例重型）的临床及影像资料。另...     

Quantitative assessment of right ventricular function and pulmonary regurgitation in surgically repaired tetralogy of Fallot using 256-slice CT: comparison with 3-Tesla MRI

Objectives

To compare 256-slice cardiac computed tomography (CCT) with cardiac magnetic resonance (CMR) imaging to assess right ventricular (RV) function and pulmonary regurgitant fraction (PRF) in patients with repaired tetralogy of Fallot (TOF).

Methods

Thirty-three consecutive patients with repaired TOF underwent retrospective ECG-gated CCT and 3-Tesla CMR. RV and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were measured using CCT and CMR. PRF-CCT (%) was defined as (RVSV???LVSV)/RVSV. PRF-CMR (%) was measured by the phase-contrast method. Repeated measurements were performed to determine intra- and interobserver variability.

Results

CCT measurements, including PRF, correlated highly with the CMR reference (r?=?0.71–0.96). CCT overestimated RVEDV (mean difference, 17.1?±?2.9 ml), RVESV (12.9?±?2.1 ml) and RVSV (4.2?±?2.0 ml), and underestimated RVEF (?2.6?±?1.0 %) and PRF (?9.1?±?2.0 %) compared with CMR. The limits of agreement between CCT and CMR were in a good range for all measurements. The variability in CCT measurements was lower than those in CMR. The estimated effective radiation dose was 7.6?±?2.6 mSv.

Conclusions

256-slice CCT can assess RV function and PRF with relatively low dose radiation exposure in patients with repaired TOF, but overestimates RV volume and underestimates PRF.

Key points

? 256-slice CT assessment of RV function is highly reproducible in repaired TOF. ? Pulmonary regurgitation can be evaluated by biventricular systolic volume difference. ? CT overestimates RV volume and underestimates pulmonary regurgitation, compared with MRI.