A review on motion tracking methods for left myocardium based on cardiac cine magnetic resonance image / 生物医学工程学杂志

Due to the high spatiotemporal resolution , cardiac cine magnetic resonance imaging (CCMRI) has been widely used to evaluate the cardiac function of cardiovascular diseases such as myocardial ischemia and so on. Segmentation-based motion tracking of left myocardium is very important for comprehensive evaluation of cardiac function in the diagnosis and treatment of cardiovascular diseases. However, it is a challenge to track motion of left myocardium, which is homogeneous and cannot provide effective motion information. In this paper, CCMRI imaging techniques for myocardial motion tracking are introduced firstly. Then approaches for motion tracking of left myocardium based on CCMRI image are described in details and are summarized and prospected at the end, which not only helps beginners to have a quick and comprehensive understanding on this topic, but also provides theoretical reference to related researchers for further optimization of approaches for motion tracking of left myocardium. From the current study, motion tracking approaches for left myocardium based on CCMRI image make comprehensive use of the spatiotemporal motion characteristics of CCMRI image, the motion and structures of myocardium of left ventricle and so on, which can make up for the shortcomings of sparse motion information of CCMRI image. However, it still needs improved constraint framework, verification methods and so on.

Two-shot compressed sensing techniques accelerate cardiac cine sequence acquisition and quantitative evaluation of the diagnostic efficacy / 第二军医大学学报

Objective To perform cardiac magnetic resonance (CMR) examination with 2-shot compressed sensing (CS) cardiac cine imaging (cine) technique, so as to obtain high-quality images that can quickly and accurately assess cardiac function and are closer to the standard cine sequence. Methods The patients, who underwent CMR examination in Department of Radiology of Peking Union Medical College Hospital of Chinese Academy of Medical Sciences & Peking Union Medical College from Jul. to Sep. 2018, were continuously enrolled. All enrolled patients received the standard cine sequence, single-shot (ss) CS cine sequence and 2-shot CS cine sequence image acquisition. Quantitative analyses of image quality and cardiac function were performed on each cine image acquired from different sequences. Results Twenty-two patients completed the three types of cine sequences. The average acquisition time of standard cine sequence, ss CS cine sequence and 2-shot CS cine sequence was (102.50±18.55), (20.50±3.71) and (30.75±5.57) s, respectively. The median total image quality scores of the standard, ss CS and 2-shot CS cine sequences were 4, 3 and 4, respectively. There was significant difference in the total quality scores between the standard cine sequence and the ss CS cine sequence (Z=-2.828, P=0.005), while there was no significant difference between the standard cine sequence and the 2-shot CS cine sequence (Z=-1.000, P=0.317). In the quantitative study of cardiac function parameters, left ventricular myocardial mass was significantly different between the standard cine sequence and the ss CS cine sequence (100.25 [47.30-136.02] g vs 101.25 [48.30-135.30] g, Z=-2.484, P=0.013), but there were no significant differences in the other parameters. There were no significant differences in the cardiac function parameters between the standard cine sequence and the 2-shot cine sequence. Spearman correlation analysis showed that there were good correlations in the cardiac function parameters between the standard cine and the ss CS cine, and the standard cine and the 2-shot CS cine (all P<0.01). Conclusion The acquisition time of 2-shot CS cine and ss CS cine sequences is significantly shorter than that of standard cine sequence. However, 2-shot CS cine sequence can obtain images closer to the images obatined by standard cine sequence, which can be use d to accurately evaluate the cardiac function.

Cardiac magnetic resonance in evaluating cardiac function: The status and advance / 第二军医大学学报

Clinical evaluation of cardiac function is routine and important. Cardiac magnetic resonance (CMR) cine sequence can obtain dynamic images of the whole cardiac cycle. Based on echocardiographic techniques, CMR has been used to establish a set of scanning sequences and an evaluation index system to evaluate cardiac function, including ejection fraction, ventricular mass index, strain, interventricular septum curvature ratio, tricuspid annular plane systolic excursion and vascular compliance. Understanding the principles, significance and indications of these indicators is helpful to optimize the scanning sequence and make timely and effective diagnosis, which is of great significance for clinical treatment and prognosis evaluation. This review sums up the status and progress of clinical application of CMR in evaluation of cardiac function.

Monitoring of cerebrospinal fluid dynamics in a model of brain herniation induced by acute intracranial hypertension by PC cine MRI / 中华急诊医学杂志

Objective To explore the monitoring of cerebrospinal fluid (CSF) dynamics in a model of brain herniation induced by acute intracranial hypertension in Guangxi Bama-Mini pigs by phasecontrast cine magnetic resonance imaging (PC cine MRI).Methods Femoral artery blood were extracted from 10 pigs,and injected into the frontal and temporal parietal lobe to make a model of brain herniation induced by acute intracranial hypertension.The mean arterial blood pressure (MAP),intracranial pressure (ICP),and cerebral perfusion pressure (CPP) were monitored.Routine T1WI,T2WI,coronal,sagittal and cerebrospinal fluid flow sequence (fast PC cine slice) which positioned on the cervical 3 (C3) vertebral body as the center and perpendicular to the spinal scans were performed on all experimental animals before and after blood injection with 3.0T Magnetic Resonance Imaging.The ICP,MAP,CPP,the absolute values of CSF peak flow velocity and the absolute value of carotid peak flow velocity before and after blood injection were compared.Results The ICP,MAP,CPP,and the absolute value of CSF peak flow velocity before injection of autologous arterial blood were statistically significant as compared with those after blood injection [(6.80±2.044) mmHg vs (52.20±1.619) mmHg,(76.80±7.068) mmHg vs (142.80±12.399) mmHg,(70.00±6.074) mmHg vs (90.50±12.250) mmHg,and the absolute value of CSF peak flow velocity was (243.20±77.671) mm/s vs (201.40±55.482) mm/s,respectively,P＜0.01].The absolute value of the peak velocity of the carotid artery before blood injection was not statistically significant compared with that after blood injection [(876.80±239.908) mm/s vs (799.40±241.829) mm/s,P＞0.05].Conclusion After the formation of brain herniation induced by acute intracranial hypertension,the CSF flow in the C3 level spinal canal showed a low dynamic change,and the CSF flow velocity waveform was disordered and malformed.The non-invasive measurement of CSF dynamics by PC cine MRI can provide an important basis for the change of CSF dynamics in the model of brain herniation induced by acute intracranial hypertension,and provide a theoretical basis for further research on damage control neurosurgery in the future.

Assessment of Left Ventricular Function with Single Breath-Hold Magnetic Resonance Cine Imaging in Patients with Arrhythmia

PURPOSE: To evaluate quantification results of single breath-hold (SBH) magnetic resonance (MR) cine imaging compared to results of conventional multiple breath-hold (MBH) technique for left ventricular (LV) function in patients with cardiac arrhythmia. MATERIALS AND METHODS: MR images of patients with arrhythmia who underwent MBH and SBH cine imaging at the same time on a 1.5T MR scanner were retrospectively reviewed. Both SBH and MBH cine imaging were performed with balanced steady state free precession. SBH scans were acquired using temporal parallel acquisition technique (TPAT). Fifty patients (65.4 ± 12.3 years, 72% men) were included. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), myocardial mass, and LV regional wall motion were evaluated. RESULTS: EF, myocardial mass, and regional wall motion were not significantly different between SBH and MBH acquisition techniques (all P-values > 0.05). EDV, ESV, and SV were significant difference between the two techniques. These parameters for SBH cine imaging with TPAT tended to lower than those in MBH. EF and myocardial mass of SBH cine imaging with TPAT showed good correlation with values of MBH cine imaging in Passing-Bablok regression charts and Bland-Altman plots. However, SBH imaging required significantly shorter acquisition time than MBH cine imaging (15 ± 7 sec vs. 293 ± 104 sec, P < 0.001). CONCLUSION: SBH cine imaging with TPAT permits shorter acquisition time with assessment results of global and regional LV function comparable to those with MBH cine imaging in patients with arrhythmia.

Application of cardiac magnetic resonance cine imaging in diagnosis and treatment of heart failure with preserved ejection fraction / 第二军医大学学报

Objective To explore the role of cine sequence of cardiac magnetic resonance (CMR) imaging in evaluating left ventricular (LV) diastolic function in patients with heart failure with preserved ejection fraction (HFpEF). Methods LV two-chamber, three-chamber, four-chamber long-axis and series of short-axis cine images were obtained from 30 patients with HFpEF (HFpEF group) and 15 cases with normal cardiac function (control group) using CMR examination. LV volume-time curve (VTC) and global strain curves were drawn. Peak filling rate and peak filling volume, global longitudinal, global radial, global circumferential peak strain and peak diastolic strain rate were compared between the two groups. Results Compared with the control group, LV remodeling index (LVRI) in the HFpEF group was significantly increased (0.86±0.15 vs 0.73±0.08, P<0.05), first peak filling rate/second peak filling rate (PFR1/PFR2) was significantly decreased or even inverted (0.74 ±0.14 vs 1.43±0.34, P=0.001), and first filling volume (FV1) and FV1/total filling volume (FV1/FV) were significantly decreased (26.24±9.74 vs 31.30±5.17, P<0.05; 0.59±0.05 vs 0.69±0.03, P<0.05). Global longitudinal peak strain (GLS) ([-14.96±1.79]% vs[-20.96±0.84]%,P<0.01), global longitudinal diastolic peak strain rate (0.65±0.16 vs 1.29±0.27, P<0.05), global radial diastolic peak strain rate (-2.23±0.71 vs -3.80±1.13, P<0.05) and global circumferential diastolic peak strain rate (GDCSR) (1.02±0.14 vs 1.77±0.63, P<0.05) in the HFpEF group were significantly decreased versus control group. Conclusion LVRI, PFR1/PFR2, FV1 and GDCSR obtained by CMR can accurately evaluate the changes of LV diastolic function in HFpEF, which may play important roles in the diagnosis and treatment of HFpEF.

Comparison of Preoperative Screening for Patients with Obstructive Sleep Apnea Hypopnea Syndrome by Cinema Magnetic Resonance and Fiber Optic Laryngoscope / 听力学及言语疾病杂志

Objective To localize the upper airway obstruction of patients with obstructive sleep apnea hypopnea syndrome (OSAHS)with the Cinema Magnetic Resonance(Cine-MR) and fiber optic laryngoscope with Müller maneuver(FLMM)before operation and discuss the clinical application values.Methods Before operation, FLMM and Cine-MR were applied to 22 patients diagnosed as OSAHS by Polysomnography(PSG).Medical examinations conducted in this study from September 2015 to April 2016 to examine the obstruction of the soft palate region, the lingual region and epiglottis.Results There were complete agreements between the Cine-MR and FLMM at locating obstruction sites of the soft palate (n=22/n=22),and there were moderate agreements between the Cine-MR and FLMM in locating obstruction sites of the retroglottal region(n=13/n=6),epiglottal region (n=4/n=2)and multiple level(n=13/n=6), respectively.Conclusion For those moderate and severe OSAHS patients with multiple sites obstruction , the preoperative application of the Cine-MR and FLMM together will be better in locating the obstruction sites.