PURPOSE: A new compressed sensing technique by iterative truncation of small transformed coefficients (ITSC) is proposed for fast cardiac CINE MRI. MATERIALS AND METHODS: The proposed reconstruction is composed of two processes: truncation of the small transformed coefficients in the r-f domain, and restoration of the measured data in the k-t domain. The two processes are sequentially applied iteratively until the reconstructed images converge, with the assumption that the cardiac CINE images are inherently sparse in the r-f domain. A novel sampling strategy to reduce the normalized mean square error of the reconstructed images is proposed. RESULTS: The technique shows the least normalized mean square error among the four methods under comparison (zero filling, view sharing, k-t FOCUSS, and ITSC). Application of ITSC for multi-slice cardiac CINE imaging was tested with the number of slices of 2 to 8 in a single breath-hold, to demonstrate the clinical usefulness of the technique. CONCLUSIONS: Reconstructed images with the compression factors of 3-4 appear very close to the images without compression. Furthermore the proposed algorithm is computationally efficient and is stable without using matrix inversion during the reconstruction.
Magnetic Resonance Imaging, Cine*

No abstract available.
Humans ; Magnetic Resonance Imaging, Cine* ; Spinal Cord Diseases*

OBJECTIVE: To evaluate the changes of intracranial cerebrospinal fluid(CSF) dynamics in communicating hydrocephalus, the authors present an analysis of various parameters of cine magnetic resonance(MR) CSF flow images in case of progressive communicating hydrocephalus. METHODS: The MR images were obtained with 1.5T(GE Signa, GE Medical Systems, Milwaukee, USA) unit using the 2 dimensional cine phase contrast sequence with cardiac gating and gradient recalled echo imaging in 10 communicating hydrocephalus and 10 controls. Various parameters of the aqueduct and cervicomedullary subarachnoid space were plotted as wave forms. The wave forms were analyzed for configurations, amplitude parameters(Vmax, Vmin, Vdif), and temporal parameters(R-MSV, R-D, R-MDV, R-S). The statistical significance of each parameter examined with paired t-test. RESULTS: Distinct reproducible configuration features were obtained at both ROIs. We could determine the statistically significant differences between control and communicating hydrocephalus in temporal parameters at the aqueduct level. There was no significant differences at the cervicomedullary subarachnoid space level. In communicating hydrocephalus, the graph showed R-MDV(p=0.005) and R-S(p=0.001) shortening at the aqueduct. CONCLUSION: The analysis of cine MR CSF flow study may be helpful for diagnosing the communicating hydrocephalus and even deciding the necessity of shunting procedures. The temporal parameters are more important than amplitude parameters for diagnosing communicating hydrocephalus.
Cerebrospinal Fluid ; Hydrocephalus* ; Magnetic Resonance Imaging, Cine ; Subarachnoid Space

PURPOSE: The purpose of this study was to evaluate comparison of static MRI and pseudo-dynamic (cine) MRI in temporomandibular joint (TMJ) disorder patients. MATERIALS AND METHODS: In this investigation, 33 patients with TMJ disorders were examined using both conventional static MRI and pseudo-dynamic MRI. Multiple spoiled gradient recalled acquisition in the steady state (SPGR) images were obtained when mouth opened and closed. Proton density weighted images were obtained at the closed and open mouth position in static MRI. Two oral and maxillofacial radiologists evaluated location of the articular disk, movement of condyle and bony change respectively and the posterior boundary of articular disk was obtained. RESULTS: No statistically significant difference was found in the observation of articular disk position, mandibular condylar movement and posterior boundary of articular disk using static MRI and pseudo-dynamic MRI (P>0.05). Statistically significant difference was noted in bony changes of condyle using static MRI and pseudo-dynamic MRI (P<0.05). CONCLUSION: This study showed that pseudo-dynamic MRI didn't make a difference in diagnosing internal derangement of TMJ in comparison with static MRI. But it was considered as an additional method to be supplemented in observing bony change.
Humans ; Joints* ; Magnetic Resonance Imaging* ; Magnetic Resonance Imaging, Cine ; Mouth ; Protons ; Temporomandibular Joint ; Temporomandibular Joint Disorders

Phase contrast magnetic resonance imaging techniques can be used to evaluate the to-and-fro motion of cerebrospinal fluid(CSF) throughout CSF pathways between the ventricles and subarachnoid space of the brain and spine. This CSF motion is due to transmitted cardiac pulsation from systolic expansion of the cerebral hemispheres. To cover the entire cardiac cycle, peripheral cardiac triggering was used. Using this technique, we analyzed quantitative CSF motion over a cardiac cycle to distinguish normal CSF flow from that seen in hydrocephalus. We tested the reproducibility of the aqueductal CSF signal intensity on a phase contrast cine MR sequence in 28 patients with normal ventricle. Sixteen patients with obstructive hydrocephalus and 11 patients with normal pressure hydrocephalus(NPH) were investigated with the sequence before and after CSF diversion. The peak CSF flow velocity in aqueduct was significantly increased in patients with NPH and significantly decreased in patients with obstructive hydrocephalus(NPH group: 6.71cm/sec, control group: 2.94cm/sec, obstructive group; less than 1.0cm/sec). After LP shunting in NPH group, retrograde flow signal curves were anterogradely converted and the peak flow velocities were somewhat decreased(mean: 5.10cm/sec). The clinical diagnosis of NPH was well correlated with the results of cine MRI. After endoscopic third ventriculostomy in obstructive group, we could note increased CSF flow velocity both at prepontine cistern and precordal subarachnoid space with markedly increased flow at prepontine cistern. Phase contrast cine MRI is useful in evaluatng the CSF dynamics in patients with hyperdynamic aqueductal CSF (NPH) or aqueductal obstruction(obstructive hydrocephalus).
Brain ; Cerebrospinal Fluid* ; Cerebrum ; Diagnosis ; Humans ; Hydrocephalus ; Magnetic Resonance Imaging ; Magnetic Resonance Imaging, Cine ; Spine ; Subarachnoid Space ; Ventriculostomy

BACKGROUND: Cine MR imaging has been found to bo a non-invasive technique in evaluation cardiac anatomy and cardiovascular function in a variety of cardiac diseases. The capability of this technique for quantatively estimating the severity of regurgitation has not been tested in newborns. The purpose of this study is to compare the degees of tricuspid regurgitation by echorcardiography with those by cine MRI, and verify the utility of MRi in evaluating tricuspid regurgitation. METHODS: Fifty-one newborns with tricuspid regurgitation were evaluated on the same day by echocardiography and cine MRI. Area and regurgitant fraction of area were estimated at four chamber view by two techniques. RESULTS: The area of tricuspid regurgitation was similar by two techniques. The correlation for the area(r=0.66, p<0.025) and the regurgitant area fraction(r=0.647, p<0.025) of tricuspid regurgitation obained by cine MRI with echocardiographic data was good. CONCLUSION: Cine MR imaging can provide quantative data estimating for evaluation of tricuspid regurgitation in newborns.
Echocardiography ; Echocardiography, Doppler* ; Heart Diseases ; Humans ; Infant, Newborn* ; Magnetic Resonance Imaging ; Magnetic Resonance Imaging, Cine* ; Tricuspid Valve Insufficiency*

Echocardiography and catheterization angiography suffer certain limitations in the evaluation of congenital heart diseases in adults, though these are overcome by MRI, in which a wide field-of view, unlimited multiplanar imaging capability and three-dimensional contrast-enhanced MR angiography techniques are used. In adults, recently introduced fast imaging techniques provide cardiac MR images of sufficient quality and with less artifacts. Ventricular volume, ejection fraction, and vascular flow measurements, including pressure gradients and pulmonary-to-systemic flow ratio, can be calculated or obtained using fast cine MRI, phase-contrast MR flow-velocity mapping, and semiautomatic analysis software. MRI is superior to echocardiography in diagnosing partial anomalous pulmonary venous connection, unroofed coronary sinus, anomalies of the pulmonary arteries, aorta and systemic veins, complex heart diseases, and postsurgical sequelae. Biventricular function is reliably evaluated with cine MRI after repair of tetralogy of Fallot, and Senning's and Mustard's operations. MRI has an important and growing role in the morphologic and functional assessment of congenital heart diseases in adolescents and adults.
Adolescent ; Adult ; Heart Defects, Congenital/*diagnosis ; Human ; *Magnetic Resonance Imaging ; *Magnetic Resonance Imaging, Cine ; Support, Non-U.S. Gov't

OBJECTIVE: To test whether the method utilizing three-dimensional (3D) whole-heart MRI has an additional benefit over that utilizing conventional two-dimensional (2D) cine MRI in quantifying ventricular volumes. MATERIALS AND METHODS: In 110 patients with congenital heart disease, a navigator-gated, 3D whole-heart MRI during end-systole (ES) and end-diastole (ED), 2D short-axis cine MRI, and phase contrast MRI of the great arteries were acquired. Ventricular volumes were measured by using a 3D threshold-based segmentation for 3D whole-heart MRI and by using a simplified contouring for 2D cine MRI. The cardiac trigger delays of 3D whole-heart MRI were compared with those of a 2D cine MRI. The stroke volumes calculated from the ventricular volumes were compared with the arterial flow volumes, measured by phase contrast MRI. RESULTS: The ES and ED trigger delays of whole-heart MRI were significantly less than cine MRI for both the left ventricle (−16.8 ± 35.9 ms for ES, −59.0 ± 90.4 ms for ED; p < 0.001) and the right ventricle (−58.8 ± 30.6 ms for ES, −104.9 ± 92.7 ms for ED; p < 0.001). Compared with the arterial flow volumes, 2D cine MRI significantly overestimated the left ventricular stroke volumes (8.7 ± 8.9 mL, p < 0.001) and the 3D whole-heart MRI significantly underestimated the right ventricular stroke volumes (−22.7 ± 22.9 mL, p < 0.001). CONCLUSION: Three-dimensional whole-heart MRI is often subject to early timing of the ED phase, potentially leading to the underestimation of the right ventricular stroke volumes.
Arteries ; Heart Defects, Congenital ; Heart Ventricles ; Humans ; Magnetic Resonance Imaging* ; Magnetic Resonance Imaging, Cine* ; Methods ; Stroke Volume

PURPOSE: We investigate biases in the assessments of left ventricular function (LVF), by compressed sensing (CS)-cine magnetic resonance imaging (MRI). MATERIALS AND METHODS: Cardiovascular cine images with short axis view, were obtained for 8 volunteers without CS. LVFs were assessed with subsampled data, with compression factors (CF) of 2, 3, 4, and 8. A semi-automatic segmentation program was used, for the assessment. The assessments by 3 CS methods (ITSC, FOCUSS, and view sharing (VS)), were compared to those without CS. Bland-Altman analysis and paired t-test were used, for comparison. In addition, real-time CS-cine imaging was also performed, with CF of 2, 3, 4, and 8 for the same volunteers. Assessments of LVF were similarly made, for CS data. A fixed compensation technique is suggested, to reduce the bias. RESULTS: The assessment of LVF by CS-cine, includes bias and random noise. Bias appeared much larger than random noise. Median of end-diastolic volume (EDV) with CS-cine (ITSC or FOCUSS) appeared −1.4% to −7.1% smaller, compared to that of standard cine, depending on CF from (2 to 8). End-systolic volume (ESV) appeared +1.6% to +14.3% larger, stroke volume (SV), −2.4% to −16.4% smaller, and ejection fraction (EF), −1.1% to −9.2% smaller, with P < 0.05. Bias was reduced from −5.6% to −1.8% for EF, by compensation applied to real-time CS-cine (CF = 8). CONCLUSION: Loss of temporal resolution by adopting missing data from nearby cardiac frames, causes an underestimation for EDV, and an overestimation for ESV, resulting in underestimations for SV and EF. The bias is not random. Thus it should be removed or reduced for better diagnosis. A fixed compensation is suggested, to reduce bias in the assessment of LVF.
Bias (Epidemiology) ; Compensation and Redress ; Diagnosis ; Magnetic Resonance Imaging ; Magnetic Resonance Imaging, Cine ; Noise ; Stroke Volume ; Ventricular Function, Left ; Volunteers

OBJECTIVE: Segmented cardiac cine magnetic resonance imaging (MRI) is the gold standard for cardiac ventricular volumetric assessment. In patients with difficulty in breath-holding or arrhythmia, this technique may generate images with inadequate quality for diagnosis. Real-time cardiac cine MRI has been developed to address this limitation. We aimed to assess the performance of retrospective electrocardiography-gated real-time cine MRI at 3T for left ventricular (LV) volume and mass measurement. MATERIALS AND METHODS: Fifty-one patients were consecutively enrolled. A series of short-axis cine images covering the entire left ventricle using both segmented and real-time balanced steady-state free precession cardiac cine MRI were obtained. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and LV mass were measured. The agreement and correlation of the parameters were assessed. Additionally, image quality was evaluated using European CMR Registry (Euro-CMR) score and structure visibility rating. RESULTS: In patients without difficulty in breath-holding or arrhythmia, no significant difference was found in Euro-CMR score between the two techniques (0.3 ± 0.7 vs. 0.3 ± 0.5, p > 0.05). Good agreements and correlations were found between the techniques for measuring EDV, ESV, EF, SV, and LV mass. In patients with difficulty in breath-holding or arrhythmia, segmented cine MRI had a significant higher Euro-CMR score (2.3 ± 1.2 vs. 0.4 ± 0.5, p < 0.001). CONCLUSION: Real-time cine MRI at 3T allowed the assessment of LV volume with high accuracy and showed a significantly better image quality compared to that of segmented cine MRI in patients with difficulty in breath-holding and arrhythmia.
Arrhythmias, Cardiac ; Diagnosis ; Heart Ventricles ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Imaging, Cine* ; Retrospective Studies* ; Stroke Volume