ABSTRACT
OBJECTIVE: Stress perfusion magnetic resonance imaging (MSPMRI) is an established technique for the assessment of myocardial perfusion. Shortcomings at 1.5 T are low signal to noise ratio (SNR) and contrast to noise ratio (CNR). One approach to overcome these shortcomings is to increase field strength and contrast concentration. The aim of our study was to investigate the diagnostic capability of high resolution MSPMRI at 3-T field strength using a 1 M contrast agent. MATERIAL AND METHODS: Fifty-seven patients (62.3 +/- 11.0 years) with symptoms of coronary artery disease (CAD) were examined at 3 T. MMRSPI was assessed using a 2D saturation recovery gradient echo (SR GRE) sequence in short axis orientation (TR 1.9 ms, TE 1.0 ms, flip 12 degrees , 0.1 mmol gadobutrol/kg body weight (bw), 140 microg adenosine/kg bw/min). Perfusion images were assessed visually and semiquantitatively (upslope, peak signal intensity (SI), and myocardial perfusion reserve index (MPRI)). Standard of reference was invasive coronary angiography. RESULTS: Stress-induced hypoperfusion was found in 43 patients. Sensitivity for hemodynamically relevant CAD (stenoses greater than 70%) was 95%/98%, specificity 80%/87%, diagnostic accuracy 91%/95% (reader 1/reader 2). The MPRI was significantly lower in hypoperfused myocardium (1.3 +/- 0.2) compared with normal myocardium (2.6 +/- 0.7). CONCLUSION: High resolution MMRSPI at 3 T using 1 M contrast agent under daily routine conditions provides reliable detection of stress-induced myocardial hypoperfusion with higher diagnostic accuracy than 1.5-T conditions.
Subject(s)
Adenosine , Coronary Artery Disease/diagnosis , Image Enhancement/methods , Magnetic Resonance Angiography/methods , Organometallic Compounds , Perfusion Imaging/methods , Ventricular Dysfunction, Left/diagnosis , Contrast Media , Coronary Artery Disease/complications , Exercise Test , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Ventricular Dysfunction, Left/etiologyABSTRACT
BACKGROUND: Patients with congenital heart disease frequently have complex cardiac and vascular malformations requiring detailed non-invasive diagnostic evaluation including functional parameters. OBJECTIVE: To evaluate the morphological and functional information provided by a novel 3-D cine steady-state free-precession (SSFP) sequence. MATERIALS AND METHODS: Twenty consecutive children (mean age 2.2 years, nine boys) were examined using a 1.5-T MR system including 2-D cine gradient-recalled-echo sequences, static 3-D SSFP and 3-D cine SSFP sequences. RESULTS: Measurement of ventricular structures and volumes showed close agreement between the 3-D cine SSFP sequence and the 2-D cine gradient-recalled-echo and static 3-D SSFP sequences (left ventricular volumes mean difference 1.0-1.9 ml and 8.8-11.4%, respectively; right ventricular volumes 1.7-2.1 ml and 9.9-16.9%, respectively). No systematic bias was observed. CONCLUSION: 3-D cine MRI provides anatomic as well as functional information with sufficient spatial and temporal resolution in free-breathing infants with congenital heart disease.
Subject(s)
Heart Defects, Congenital/pathology , Imaging, Three-Dimensional/methods , Magnetic Resonance Imaging, Cine/methods , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Reproducibility of Results , Respiratory Mechanics , Sensitivity and SpecificitySubject(s)
Aortic Rupture/diagnosis , Heart Murmurs/diagnosis , Sinus of Valsalva/diagnostic imaging , Ventricular Dysfunction, Right/diagnosis , Adult , Aortic Rupture/complications , Aortic Rupture/surgery , Diagnosis, Differential , Heart Atria/diagnostic imaging , Heart Murmurs/etiology , Heart Murmurs/surgery , Humans , Male , Radiography , Sinus of Valsalva/surgery , Ventricular Dysfunction, Right/complications , Ventricular Dysfunction, Right/surgeryABSTRACT
The study was approved by the local ethics committee, and informed consent was provided by all participants prior to the examination. The aim of the study was to assess the feasibility of whole-body three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiography with parallel imaging in the phase- and section-encoding directions (ie, integrated parallel acquisition technique [iPAT(2); Siemens, Erlangen, Germany]) for all anatomic imaging stations in combination with a single injection of contrast material. Whole-body contrast-enhanced MR angiography was performed in 23 patients at 3.0 T. Images were evaluated by two independent observers for quality on a four-point scale (where a score of 1 indicated poor image quality and a score of 4, excellent image quality); signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for representative vessel regions in each station. Mean image quality scores were 3.13 +/- 1.15 (standard deviation) and 3.17 +/- 1.14 for observers 1 and 2, respectively (kappa = 0.81). Signal intensity measurements revealed mean SNR values between 36.2 +/- 8.0 and 56.2 +/- 17.7 and mean CNR values between 29.0 +/- 7.4 and 48.2 +/- 15.7. The data suggest that contrast-enhanced MR angiography with iPAT(2) is feasible for whole-body applications and allows acquisition of 3D data sets with adequate spatial resolution within short measurement times, facilitating a single injection of contrast material.
