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ABSTRACT: The purpose of this study was to establish the prognostic value of measuring heart fatty acid-binding protein (H-FABP) in patients with suspected acute coronary syndrome (ACS) (in particular, low- to intermediate-risk patients), in addition to troponin measured with the latest third-generation troponin assay.
We have previously shown that H-FABP is a useful prognostic marker in patients with proven ACS.
Patients (n = 1,080) consecutively admitted to the hospital with suspected ACS were recruited over 46 weeks. Siemens Advia Ultra-TnI (Siemens Healthcare Diagnostics, Newbury, United Kingdom) and Randox Evidence H-FABP (Randox Laboratories, Ltd., Co., Antrim, United Kingdom) were analyzed on samples collected 12 to 24 h from symptom onset. After exclusion of patients with ST-segment elevation and new left bundle branch block, 955 patients were included in the analysis.
The primary outcome measure of death or readmission with myocardial infarction after a minimum follow-up period of 12 months (median 18 months) occurred in 96 of 955 patients (10.1%). The H-FABP concentration was an independent predictor of death or myocardial infarction, after multivariate adjustment. Patients with H-FABP concentrations >6.48 microg/l had significantly increased risk of adverse events (adjusted hazard ratio: 2.62, 95% confidence interval: 1.30 to 5.28, p = 0.007). Among troponin-negative patients (which constituted 79.2% of the cohort), the aforementioned cutoff of 6.48 microg/l identified patients at very high risk for adverse outcomes independent of patient age and serum creatinine.
We have demonstrated that the prognostic value of elevated H-FABP is additive to troponin in low- and intermediate-risk patients with suspected ACS. Other studies suggest that our observations reflect the value of H-FABP as a marker of myocardial ischemia, even in the absence of frank necrosis.
Journal of the American College of Cardiology 06/2010; 55(23):2590-8. · 14.16 Impact Factor
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ABSTRACT: Over the last decade, magnetic resonance imaging (MRI) has become established as a useful referral diagnostic method in veterinary medicine that is widely used in small animal brain and spinal diseases, aural, nasal and orbital disorders, planning soft tissue surgery, oncology and small animal and equine orthopaedics. The use of MRI in these disciplines has grown due to its unparalleled capability to image soft tissue structures. This has been exploited in human cardiology where, despite the inherent difficulties in imaging a moving, contractile structure, cardiac MRI (CMRI) has become the optimal technique for the morphological assessment and quantification of ventricular function. Both CMRI hardware and software systems have developed rapidly in the last 10 years but although several preliminary veterinary CMRI studies have been reported, the technique's growth has been limited and is currently used primarily in clinical research. A review of published studies is presented with a description of CMRI technology and the potential of CMRI is discussed along with some of the reasons for its limited usage.
The Veterinary Journal 02/2009; 183(2):124-34. · 2.24 Impact Factor
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ABSTRACT: To prospectively compare a selective short axis slice positioning method (selective 3-of-5) used in combination with a single long-axis slice, to the conventional short axis multi-slice technique in the assessment of myocardial viability.
Thirty-one patients with recent or chronic ST segment elevation myocardial infarct (STEMI) were recruited to undergo delayed enhancement (DE) cardiac magnetic resonance imaging (CMR). All patients underwent both methods of DE imaging, with subsequent review of both sets of data by two experienced observers. Sensitivity and specificity, as well as intra and interobserver reproducibility for both techniques were assessed.
There was good agreement between the selective 3-of-5 and the conventional multi-slice method for the assessment of viability, with no significant difference in results for sensitivity or reproducibility between the techniques.
In patients with STEMI, a selective 3-of-5 short axis slice acquisition used in combination with a single vertical long-axis slice can be utilised to produce a standard American Heart Association (AHA) 17-segment model for the assessment of myocardial viability.
European Journal of Radiology 05/2008; 66(1):42-7. · 2.61 Impact Factor
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ABSTRACT: T(1) maps obtained with modified Look-Locker inversion recovery (MOLLI) can be used to measure myocardial T(1). We aimed to evaluate the potential of MOLLI T(1) mapping for the assessment of acute and chronic myocardial infarction (MI). A total of 24 patients with a first MI underwent MRI within 8 days and after 6 months. T(1) mapping was performed at baseline and at selected intervals between 2-20 min following administration of gadopentetate dimeglumine (Gd-DTPA). Delayed-enhancement (DE) imaging served as the reference standard for delineation of the infarct zone. On T(1) maps the myocardial T(1) relaxation time was assessed in hyperenhanced areas, hypoenhanced infarct cores, and remote myocardium. The planimetric size of myocardial areas with standardized T(1) threshold values was measured. Acute and chronic MI exhibited different T(1) changes. Precontrast threshold T(1) maps detected segmental abnormalities caused by acute MI with 96% sensitivity and 91% specificity. Agreement between measurements of infarct size from T(1) mapping and DE imaging was higher in chronic than in acute infarcts. Precontrast T(1) maps enable the detection of acute MI. Acute and chronic MI show different patterns of T(1) changes. Standardized T(1) thresholds provide the potential to dichotomously identify areas of infarction.
Magnetic Resonance in Medicine 08/2007; 58(1):34-40. · 2.96 Impact Factor
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ABSTRACT: The recent introduction of "flat-panel detector" (FD)-based cardiac catheterisation laboratories should offer improvements in image quality and/or dose efficiency over X-ray systems of conventional design. We compared three X-ray systems, one image-intensifier (II)-based system (system A), and two FD-based designs (systems B and C), assessing their image quality and dose efficiency. Phantom measurements were performed to assess dose rates in fluoroscopy and cine acquisition. Phantom dose rates were broadly similar for all systems, with all systems classified as offering "low" dose rates in fluoroscopy on standard phantoms. Patient X-ray dose rate and subjective image quality was assessed for 90 patients. Dose area product (DAP) rates were similar for all systems, except system C, which had a lower DAP rate in fluoroscopy. In terms of subjective image quality, the order of preference was (best to worst): system C, system A, system B. This study indicates that the use of an FD detector does not infer an automatic improvement in image quality or dose efficiency over II based designs. Specification and configuration of all of the components in the X-ray system contribute to the dose levels used and image quality achieved.
European Radiology 08/2007; 17(7):1787-94. · 3.22 Impact Factor
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ABSTRACT: Sympathetic activation has been implicated in the development of left ventricular hypertrophy (LVH). However, the relationship between sympathetic activation and LV mass (LVM) has not been clearly defined across a range of arterial pressure measurements. The present study was planned to determine that relationship, using cardiac magnetic resonance imaging to accurately quantify LVM, in hypertensive patients with and without LVH and in normal subjects.
Twenty-four patients with uncomplicated and untreated essential hypertension (LVH[-]) were compared with 25 patients with essential hypertension and left ventricular hypertrophy (LVH[+]) and 24 normal control subjects. Resting muscle sympathetic nerve activity was quantified as multiunit bursts and single units. Cardiac magnetic resonance imaging-determined LVM was indexed to body surface area (LVM index); in the LVH[-] group, LVM index was 67+/-2.1 g/m2, a value between those of the LVH[+] (91+/-3.4 g/m2) and normal control (57+/-2.2 g/m2) groups, respectively. The sympathetic activity in the LVH[-] group (53+/-1.3 bursts per 100 cardiac beats and 63+/-1.6 impulses per 100 cardiac beats) was between (at least P<0.001) those of the LVH[+] (66+/-1.7 bursts per 100 cardiac beats and 77+/-2.2 impulses per 100 cardiac beats) and normal control (39+/-3.0 bursts per 100 cardiac beats and 45+/-3.4 impulses per 100 cardiac beats) groups. Significant positive correlation existed between sympathetic activity and LVM index in the LVH[-] and LVH[+] groups (at least r=0.76, P<0.0001) but not in the normal control group. However, no consistent relationship existed between arterial blood pressure and sympathetic activity or LVM index.
These findings further support the hypothesis that central sympathetic activation is associated with the development of LVH in human hypertension.
Circulation 05/2007; 115(15):1999-2005. · 14.74 Impact Factor
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ABSTRACT: The aim of this study was to identify diffuse myocardial fibrosis secondary to chronic aortic regurgitation by comparing the T1 relaxation times of left ventricular myocardium in a pilot patient group with a previously established normal range of times.
Eight patients with chronic aortic regurgitation and normal coronary arteries awaiting surgical valve replacement underwent a comprehensive MRI examination that included assessment of left ventricular function, severity of valvular regurgitation, and presence of overt myocardial scar evidenced by delayed enhancement. For each patient, myocardial T1 relaxation times determined with a modified Look-Locker technique before and after contrast administration were compared with values previously established for 15 healthy volunteers.
There was no statistical difference (p > 0.05) in slice-averaged myocardial T1 relaxation times either before or after gadolinium administration in the patient group compared with the normal range of times. Segmental averaged T1 relaxation times in segments with abnormal wall motion did, however, show statistically significant differences from healthy controls 10, 15, and 20 minutes after administration of gadolinium (510 vs 476 milliseconds, p = 0.001; 532 vs 501 milliseconds, p = 0.002; 560 vs 516 milliseconds, p = 0.001, respectively). Two of the aortic regurgitation patients also had focal areas of myocardial delayed enhancement.
Segment-based myocardial T1 mapping has the potential for showing differences between relaxation times in aortic regurgitation and in normal hearts, suggesting the existence of a diffuse myocardial fibrotic process.
American Journal of Roentgenology 12/2006; 187(6):W630-5. · 2.78 Impact Factor
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ABSTRACT: The presence of left ventricular hypertrophy (LVH) in hypertension, as detected by the electrocardiogram or echocardiography, is associated with an increased risk of mortality and morbidity several times above and beyond the risk of hypertension alone. The LIFE (Losartan Intervention For Endpoint reduction in hypertension) study confirmed that pharmacological agents, which reduce LVH, confer further reduction in morbidity and mortality. This makes the identification of patients with LVH all the more important. In this article we describe the various methods available to diagnose the presence of LVH in patients with hypertension, and consider their strengths and their place in clinical practice and in research.
Journal of Hypertension 08/2006; 24(7):1223-30. · 4.02 Impact Factor
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ABSTRACT: A prospective study approved by the local ethics committee was performed to establish the normal range and reproducibility of myocardial T1 values as assessed with single-breath-hold T1 mapping with high spatial resolution. With a 1.5-T magnetic resonance (MR) imaging system, baseline and contrast material-enhanced modified Look-Locker inversion recovery, or MOLLI, imaging was performed in 15 healthy volunteers who had given written informed consent. Image quality scores and myocardial T1 values were derived for standard short-axis segments and sections. Results were compared with those from a second MR imaging study performed on the same day (baseline only) and those from a third study performed on a different day (baseline and contrast enhanced; eight volunteers). Intra- and interobserver agreement were determined. Myocardial T1 maps were obtained rapidly in a reproducible fashion. A normal range for baseline and postcontrast myocardial T1 was established (baseline mean T1 in short-axis sections, 980 msec +/- 53 [standard deviation]; 95% confidence interval: 964, 997; number of sections, 43). This technique could enable direct quantification of changes in tissue characteristics in ischemic and inflammatory myocardial diseases.
Radiology 04/2006; 238(3):1004-12. · 5.73 Impact Factor
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ABSTRACT: The aim of this study was to compare a dual-inversion-recovery black-blood (BB) magnetic resonance imaging (MRI) sequence with steady-state free precession (SSFP) for the assessment of left ventricular parameters. The improved endocardial border definition seen with SSFP was not observed at the epicardial border. Improvements in segmentation at the left ventricular epicardial border have been observed with this black-blood sequence. Left ventricular (LV) mass and LV end-diastolic volume (EDV) measurements as well as inter-observer and intra-observer variability were compared between images acquired with a dual inversion BB and SSFP sequence. The mean+/-1 standard deviation (SD) for LV EDV was 178.3+/-52.7 ml measured with SSFP and 158.8+/-62.2 ml with BB. This difference was not statistically significant (p=0.22). For SSFP, the mean value of LV mass was 124.0+/-27.0 g and 147.5+/-37.4 g for BB, a statistically significant difference (p<0.0001). The dual-inversion-recovery BB imaging showed improved reproducibility for LV mass measurements compared with SSFP and improved spatial resolution. For studies requiring LV mass measurements, the dual-inversion-recovery BB sequence offers improved spatial resolution and improved reproducibility to SSFP.
European Radiology 01/2006; 16(1):32-7. · 3.22 Impact Factor
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ABSTRACT: To evaluate the technical performance of sensitivity encoding (SENSE)-accelerated myocardial perfusion magnetic resonance (MR) imaging and prospectively assess the diagnostic accuracy of this examination for depiction of significant coronary artery disease (CAD).
All 102 subjects provided written informed consent, and the local ethics committee approved the study. A saturation-recovery segmented k-space gradient-echo pulse sequence was combined with SENSE to allow dynamic acquisition of myocardial perfusion data on four parallel short-axis MR image sections at every heartbeat. This technique was evaluated in 10 healthy volunteers and in 92 patients scheduled to undergo conventional coronary angiography. Gadopentetate dimeglumine was peripherally injected at rest and during adenosine-induced stress. The maximal upslope of the signal intensity-time profiles was plotted for 16 myocardial segments defined on three MR image sections, and a myocardial perfusion reserve index (MPRI) between stress and rest, normalized to the input function from the blood pool of the most basal section, was calculated. Areas under receiver operating characteristic curves (AUCs) were used to assess the diagnostic performance of cardiac MR imaging for depiction of greater than 70% CAD seen at coronary angiography, the reference standard.
In volunteers, the mean myocardial enhancement was 2.1 +/- 1.2 (standard deviation), with homogeneous signal intensity distribution across the segments. The diagnostic accuracy of MPRI measurements was high (AUC, 0.908; sensitivity, 88% [52 of 59 patients]; specificity, 82% [27 of 33 patients]). Diagnostic performance was similar among separate analyses of the three coronary territories and among separate analyses of data in the patients with diabetes mellitus, left ventricular hypertrophy, or myocardial infarction.
Multisection myocardial perfusion MR imaging with SENSE is feasible and has high diagnostic accuracy in the detection of CAD.
Radiology 06/2005; 235(2):423-30. · 5.73 Impact Factor
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ABSTRACT: The assessment of regional left ventricular (LV) function with cardiac magnetic resonance (MR) cine techniques requires a standardized section positioning. A simple selective short-axis method for selective positioning of three short-axis sections (basal, midcavity, apical) was tested for its accuracy, compared with accepted criteria, in 21 volunteers (mean age, 32 years +/- 11) and in 23 patients with myocardial infarction (mean age, 56 years +/- 12). Reproducibility of section positioning and of regional LV parameters was tested in the volunteers. Among the six accuracy criteria defined for standard sections, the selective short-axis approach had an average accuracy of 90.9% in volunteers and 87.7% in patients, compared with 92.1% and 90.6%, respectively, for a multisection approach covering the whole LV. There was very good reproducibility of the selected intersection gap (r = 0.89, P < .001) and of measured midcavity end-diastolic diameters in vertical (r = 0.83, P < .001) and horizontal (r = 0.85, P < .001) long-axis orientations. The proposed method produces standardized short-axis section positions that meet the recommendations for cardiac imaging. The study was approved by the local ethics committee, and all subjects gave written informed consent.
Radiology 05/2005; 235(1):229-36. · 5.73 Impact Factor
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ABSTRACT: The goal of this study was to determine: 1) if the presence of significant coronary stenosis in patients presenting with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) can be predicted by cardiac magnetic resonance (CMR) imaging; and 2) if the analysis of several CMR methods improves its diagnostic yield compared with analysis of individual methods.
With modern acquisition techniques, several CMR methods for the assessment of coronary artery disease (CAD) can be combined in a single noninvasive scanning session. Such a multicomponent CMR examination has not previously been applied to a large patient population, in particular those with a high prevalence of CAD in an acute situation.
Sixty-eight patients presenting with NSTE-ACS underwent CMR imaging of myocardial function, perfusion (rest and adenosine-stress), viability (by late contrast enhancement), and coronary artery anatomy. Visual analysis of CMR was carried out. First, all CMR data were reviewed in combination ("comprehensive analysis"). In further separate analyses, each CMR method was analyzed individually. The ability of CMR to detect coronary stenosis >/=70% on X-ray angiography was determined.
Comprehensive CMR analysis yielded a sensitivity of 96% and a specificity of 83% to predict the presence of significant coronary stenosis and was more accurate than analysis of any individual CMR method; CMR was significantly more sensitive and accurate than the Thrombolysis In Myocardial Infarction risk score (p < 0.001).
Cardiac magnetic resonance imaging accurately predicts the presence of significant CAD in patients with NSTE-ACS. In this study, a comprehensive analysis of several CMR methods improved the accuracy of the test.
Journal of the American College of Cardiology 01/2005; 44(11):2173-81. · 14.16 Impact Factor
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ABSTRACT: Cardiovascular magnetic resonance (CMR) perfusion can accurately detect coronary artery disease (CAD). However, the absence of efficient, easy-to-use and reliable image analysis software is an obstacle to its introduction into clinical practice. The aim of this study was to evaluate new color-encoded semiautomatic software for analysis of first-pass CMR perfusion in comparison to tetrofosmin myocardial single photon emission computed tomography (SPECT), using X-ray angiography as the standard of truth for the detection of CAD.
Thirty-two patients underwent both SPECT and CMR perfusion at rest and adenosine stress. Twenty of these patients also underwent X-ray angiography. Off-line CMR image analysis consisted of six steps to generate a color display of the myocardial perfusion reserve index (MPRI). The MPRI color-maps were analyzed visually and compared to SPECT.
In comparison to X-ray angiography overall accuracy was 87% for CMR and 77% for SPECT perfusion to detect significant CAD (stenosis > or =70%). In comparison with SPECT sensitivity was 80%, specificity 91%, and the overall agreement 89% for CMR.
Post-processing of CMR perfusion data using new semiautomatic software to generate and display the MPRI visually as color-encoded images is feasible and fast. In this study it yielded higher accuracy than SPECT to detect significant CAD on X-ray angiography. Correlation between SPECT and CMR accuracy for detection of perfusion defects was high. This method may accelerate the time-consuming analysis of CMR perfusion data, thus enabling a more widespread clinical utility.
The International Journal of Cardiovascular Imaging 11/2004; 20(5):371-84; discussion 385-7. · 2.29 Impact Factor
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ABSTRACT: A novel pulse sequence scheme is presented that allows the measurement and mapping of myocardial T1 in vivo on a 1.5 Tesla MR system within a single breath-hold. Two major modifications of conventional Look-Locker (LL) imaging are introduced: 1) selective data acquisition, and 2) merging of data from multiple LL experiments into one data set. Each modified LL inversion recovery (MOLLI) study consisted of three successive LL inversion recovery (IR) experiments with different inversion times. We acquired images in late diastole using a single-shot steady-state free-precession (SSFP) technique, combined with sensitivity encoding to achieve a data acquisition window of < 200 ms duration. We calculated T1 using signal intensities from regions of interest and pixel by pixel. T1 accuracy at different heart rates derived from simulated ECG signals was tested in phantoms. T1 estimates showed small systematic error for T1 values from 191 to 1196 ms. In vivo T1 mapping was performed in two healthy volunteers and in one patient with acute myocardial infarction before and after administration of Gd-DTPA. T1 values for myocardium and noncardiac structures were in good agreement with values available from the literature. The region of infarction was clearly visualized. MOLLI provides high-resolution T1 maps of human myocardium in native and post-contrast situations within a single breath-hold.
Magnetic Resonance in Medicine 07/2004; 52(1):141-6. · 2.96 Impact Factor
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ABSTRACT: To compare patients' perceived satisfaction and tolerance of magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) myocardial perfusion imaging.
A questionnaire was sent retrospectively to 41 patients who had undergone both SPECT and MRI myocardial perfusion scans at our institution. The questionnaire assessed SPECT and MRI separately, and in a separate section compared the tests directly. The answers were scored and analyzed for statistical significance by the use of Wilcoxon signed-ranks and chi2 tests.
Thirty-five completed questionnaires were returned. In a direct comparison, 12 patients (34%) preferred MRI overall, nine (26%) preferred SPECT, and 14 (40%) expressed no preference. The ratings for the overall comfort of the scans were similar, with a score of 5.8 for SPECT and 5.7 for MRI (on a scale of 1-10). More patients stated a preference for MRI on scan comfort, duration, and safety (no statistical significance), but it was less well rated than SPECT for space on the scanner (P = 0.008). Three patients (9%) stated that they would not have an MRI scan again, while two patients (6%) said they would not repeat a SPECT scan.
MRI myocardial perfusion imaging represents an acceptable alternative to SPECT with respect to patient tolerance and satisfaction.
Journal of Magnetic Resonance Imaging 05/2004; 19(4):410-6. · 2.70 Impact Factor
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ABSTRACT: The diameters and distensibility of the native pulmonary root and their effect on pulmonary autograft performance were examined pre- and postoperatively using cardiac ultrasound and magnetic resonance imaging (MRI).
Eight patients undergoing the Ross procedure were prospectively involved. The diameters of the native aortic, native pulmonary and autograft roots were measured at the level of the annulus, sinus, sinotubular junction and in the main root using MRI through the cardiac cycle. Ultrasound was also used to estimate the degree of regurgitation, both pre- and postoperatively.
The pulmonary root implanted into the systemic circulation increased in size but decreased in distensibility significantly at the sinus, sinotubular junction and main root, but not at the annulus. Postoperatively, the pulmonary autograft annulus showed a similar size and distensibility to that of the native aortic annulus. A wide range of aortic annular sizes (22-30 mm) produced clinically competent valves postoperatively. All undersized pulmonary valves showed only trivial regurgitation postoperatively. Although there was no clear correlation between root shape and valve insufficiency, two patients with mild and moderate autograft regurgitation both had divergent pulmonary roots (diameter at sinotubular junction > annulus diameter) preoperatively.
The pulmonary autograft using the root replacement technique functioned well in all but one case. The shape of the native pulmonary root may be a determinant of early autograft regurgitation, as well as the diameter and the size mismatch between the great arteries.
The Journal of heart valve disease 02/2004; 13(1):78-85. · 0.81 Impact Factor
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ABSTRACT: The feasibility of electrocardiography (ECG)-synchronized respiration with an external cuirass-type respirator in cardiac magnetic resonance (MR) imaging was evaluated. Cardiac MR imaging was performed in 10 nonsedated healthy volunteers with an ECG-triggered external respirator that was modified for use in the MR environment. Coronary MR angiograms and multiphase gradient-echo cine images were acquired with one respiratory cycle performed per cardiac cycle. The technique was feasible and in this group of volunteers resulted in equivalent image quality but shorter acquisition times than those of conventional free-breathing and breath-holding techniques.
Radiology 07/2003; 227(3):877-82. · 5.73 Impact Factor
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ABSTRACT: To establish normal ranges of left ventricular (LV) and right ventricular (RV) dimensions as determined by the current pulse sequences in cardiac magnetic resonance imaging (MRI).
Sixty normal subjects (30 male and 30 female; age range, 20-65) were examined; both turbo gradient echo (TGE) and steady-state free precession (SSFP) pulse sequences were used to obtain contiguous short-axis cine data sets from the ventricular apex to the base of the heart. The LV and RV volumes and LV mass were calculated by modified Simpson's rule.
Normal ranges were established and indexed to both body surface area (BSA) and height. There were statistically significant differences in the measurements between the genders and between TGE and SSFP pulse sequences. For TGE the LV end-diastolic volume (EDV)/BSA (mL/m(2)) in males was 74.4 +/- 14.6 and in females was 70.9 +/- 11.7, while in SSFP in males it was 82.3 +/- 14.7 and in females it was 77.7 +/- 10.8. For the TGE the LV mass/BSA (g/m(2)) in males was 77.8 +/- 9.1 and in females it was 61.5 +/- 7.5, while in SSFP in males it was 64.7 +/- 9.3 and in females it was 52.0 +/- 7.4. For TGE the RV EDV/BSA (mL/m(2)) in males was 78.4 +/- 14.0 and in females it was 67.5 +/- 12.7, while in SSFP in males it was 86.2 +/- 14.1 and in females it was 75.2 +/- 13.8.
We have provided normal ranges that are gender specific as well as data that can be used for age-specific normal ranges for both SSFP and TGE pulse sequences.
Journal of Magnetic Resonance Imaging 04/2003; 17(3):323-9. · 2.70 Impact Factor
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ABSTRACT: In coronary MR angiography, data are conventionally accepted in only short and fixed periods of the cardiac and respiratory cycles. We hypothesized that a more flexible and subject-specific approach to cardiac and respiratory gating may shorten scanning times while maintaining image quality.
We implemented an acquisition technique that uses subject-specific acquisition windows in the cardiac cycle and a motion-adapted gating window for respiratory navigator gating. Cardiac acquisition windows and trigger delays were determined individually from a coronary motion scan. Motion-adapted gating used a 2-mm acceptance window for the central 35% of k-space and a 6-mm window for the outer 65% of k-space. In 10 subjects, three-dimensional coronary MR angiograms of the right and left coronary systems were acquired with this technique (the "adaptive technique") as well as a conventional acquisition method, and the scanning times and image quality were compared. The adaptive technique was then applied prospectively to 40 patients who underwent coronary radiographic angiography.
Scanning times with the adaptive technique were reduced by a factor of 2.3 for the right coronary artery and by a factor of 2.2 for the left coronary artery system compared with the conventional technique, mainly because we were able to use longer subject-specific acquisition windows in patients with low heart rates. Subjective and objective measurements of image quality showed no significant differences between the two techniques. Prospective evaluation of MR angiograms yielded a sensitivity and specificity of 74.3% and 88.2%, respectively, to detect significant coronary artery stenoses.
Coronary MR angiography with subject-specific acquisition windows and motion-adapted respiratory gating reduces scanning times while maintaining image quality and provides high diagnostic accuracy for the detection of coronary artery stenosis.
American Journal of Roentgenology 03/2003; 180(2):505-12. · 2.78 Impact Factor
