Application of Magnetization-prepared True Fast Imaging with Steady-state Precession Sequence in Brain Tumor Enhancement / 中国医学科学院学报

Objective To evaluate the application of two-dimensional magnetization-prepared true fast imaging with steady-state precession(2D-MP-TrueFISP)sequence in brain tumor enhancement.Methods In this study,60 cases of brain tumor patients who underwent enhanced magnetic resonance imaging of brain were scanned with 2D-MP-TrueFISP/two-dimensional spoiled gradient-recalled echo(2D-SPGR)before and after enhancement.The scores of lesions on the images of 2D-MP-TrueFISP/2D-SPGR were compared.At the same level of 2D-SPGE and 2D-MP-TrueFISP,the signal intensities(SIs)of lesions,white matter,and cerebrospinal fluid were measured before and after enhancement,and the contrast ratios(CRs)of lesions were calculated.The CRs before and after 2D-SPGR/2D-MP-TrueFISP enhancement and those between 2D-SPGR and 2D-MP-TrueFISP after enhancement were compared.Results The scores of lesions after 2D-MP-TrueFISP/2D-SPGR T1WI enhancement were 9.0(9.0,9.0)and 7.0(6.0,7.0),respectively,with significant difference(

Role of MRI defecography in assessment of pelvic floor pathologies

Background: Functional disorders of the pelvic ?oor are a common clinical problem. Diagnosis and treatment of these disorders, which frequently manifest with nonspeci?c symptoms such as constipation or incontinence, remain dif?cult. MR Defecography has emerged over the last decade as a modality which additionally images the pelvic floor function in real time besides combining the advantages of previously used modalities and that of magnetic resonance i.e. multiplanar imaging, good temporal resolution and lack of radiation exposure. Dynamic MRI defecography is a relatively new imaging protocol which can be extremely useful in identification of anatomic and functional pelvic floor dysfunction such as organ prolapse, anismus and fecal incontinence. Excellent demonstration of the perirectal soft tissues allows assessment of spastic pelvic ?oor syndrome and descending perineum syndrome and visualization of enteroceles. The aim of the study was to assess causes of pelvic floor dysfunction.Methods: Authors evaluated 25 patients with cine Magnetic Resonance Defecography at our center between December 2018 and 15th May 2019. MR Defecography was done with help of 3 Tesla Somatom Seimens MRI. Ultrasound jelly was instilled into the rectum of patient via a short flexible tube while the patient lies in the lateral decubitus position on the scanner table before being moved into the gantry and was asked to defecate when instructed. Scanning was done in four phases-resting, straining, squeezing and defecation as per the standard protocol while patient lied supine.Results: Most common complaint encountered was that of constipation. Patients in age group 20-70 years were studied. Maximum patient were of the age group 40-50 years. Most common finding was organ prolapse in total 9 patients with anterior rectocele in 6 patients followed by rectal prolapse.Conclusions: Magnetic resonance defecography is an excellent modality for assessment of pelvic floor disorders. It has very good temporal resolution and high soft tissue contrast, also allows visualization of the pelvic floor function in real-time without any radiation load. Imaging the defecation process in real-time leads to a definitive diagnosis in cases of dysfunctional defecation and a precise diagnostic and pre-operative assessment in cases of organ prolapse.

Application of three-dimensional true fast imaging with steady-state precession sequence combined with diffusion tensor tractography for lumbar disc herniation / 中国介入影像与治疗学

Objective: To explore the value of three-dimensional true fast imaging with steady-state precession (3D-Ture FISP) sequence combined with diffusion tensor tractography (DTT) in determining the responsible nerve root of sciatica caused by lumbar disc herniation (LDH). Methods: MR examinations of lumbosacral region were performed on 40 LDH patients with unilateral sciatica (lesion group) and 40 healthy volunteers (control group). FA and ADC values of bilateral nerve roots were measured at L4-S1 vertebral level based on 3D-Ture FISP sequence and DTT fusing images. The responsible nerve roots of LDH patients with sciatica were detected combining with morphologic findings, course and FA and ADC values of the nerve roots shown on the fusing images. And statistical analysis was carried out. Results: All 3D-True FISP sequence and DTT fusing images could clearly show the morphology and course of nerve roots. In lesion group (51 involved nerve roots and 189 uninvolved nerve roots), 37 cases were found to be in accordance with the clinical symptoms whereas 3 cases were not. In control group (240 nerve roots), there was no statistical difference of FA and ADC values between the left and the right nerve roots (both P>0.05). The mean FA value of bilateral nerve roots was 0.346±0.042, and the mean ADC value was (1.296±0.080)mm2/s. The mean FA and ADC values of involved nerve roots in lesion group was 0.253±0.021 and (1.743±0.089)mm2/s, respectively. And the mean FA and ADC values of contralateral uninvolved nerve roots was 0.339±0.013 and (1.297±0.075)mm2/s, respectively. FA value of involved nerve roots in lesion group was significantly lower than that of contralateral uninvolved nerve roots in lesion group (t=0.806, P=0.038) and the mean FA value of control group (t=0.963, P=0.043), respectively,while ADC value significantly increased compared with contralateral uninvolved nerve roots (t=0.866, P=0.040) and control group (t=0.921, P=0.042). There was no statistical difference of the mean FA and ADC values between contralateral nerve roots in lesion group and control group (both P>0.05). Conclusion: 3D-Ture FLSP sequence combined with DTT technique can not only clearly show the anatomical morphology and course of nerve root, but also quantitatively detect the responsible nerve roots of sciatica in LDH patients, so as to provide information for clinical diagnosis and treatment.

High quality reconstruction algorithm for cardiac magnetic resonance images based on multiscale low rank modeling / 生物医学工程学杂志

Taking advantages of the sparsity or compressibility inherent in real world signals, compressed sensing (CS) can collect compressed data at the sampling rate much lower than that needed in Shannon's theorem. The combination of CS and low rank modeling is used to medical imaging techniques to increase the scanning speed of cardiac magnetic resonance (CMR), alleviate the patients' suffering and improve the images quality. The alternating direction method of multipliers (ADMM) algorithm is proposed for multiscale low rank matrix decomposition of CMR images. The algorithm performance is evaluated quantitatively by the peak signal to noise ratio (PSNR) and relative norm error (RLNE), with the human visual system and the local region magnification as the qualitative comparison. Compared to L + S, kt FOCUSS, k-t SPARSE SENSE algorithms, experimental results demonstrate that the proposed algorithm can achieve the best performance indices, and maintain the most detail features and edge contours. The proposed algorithm can encourage the development of fast imaging techniques, and improve the diagnoses values of CMR in clinical applications.

Comparison with Magnetic Resonance Three-Dimensional Sequence for Lumbar Nerve Root with Intervertebral Foramen

STUDY DESIGN: Prospective study based on magnetic resonance (MR) imaging of the lumbar spinal root of the intervertebral foramen. PURPOSE: This study was to compare MR three-dimensional (3D) sequences for the evaluation of the lumbar spinal root of the intervertebral foramen. OVERVIEW OF LITERATURE: The diagnosis of spinal disorders by MR imaging is commonly performed using two-dimensional T1- and T2-weighted images, whereas 3D MR images can be used for acquiring further detailed data using thin slices with multi-planar reconstruction. METHODS: On twenty healthy volunteers, we investigated the contrast-to-noise ratio (CNR) of the lumbar spinal root of the intervertebral foramen with a 3D balanced sequence. The sequences used were the fast imaging employing steady state acquisition and the coherent oscillatory state acquisition for the manipulation of image contrast (COSMIC). COSMIC can be used with or without fat suppression (FS). We compared these sequence to determine the optimized visualization sequence for the lumbar spinal root of the intervertebral foramen. RESULTS: For the CNR between the nerve root and the peripheral tissue, these were no significant differences between the sequences at the entry of foramen. There was a significant difference and the highest CNR was seen with COSMIC-FS for the intra- and extra-foramen. CONCLUSIONS: In this study, the findings suggest that the COSMIC-FS sequences should be used for the internal or external foramen for spinal root disorders.

MR findings and comparative study of MR sequences in several twin pregnancy with comorbidities / 实用放射学杂志

Objective To compare the applications of half-Fourier acquisition single-shot turbo spin-echo(HASTE)sequence and true fast imaging with steady state precession(True FISP)sequence for the delineation of structures and diseases in several twin pregnancy with comorbidities and to explore the clinical value of two series of fast imaging for MRI of fetus.Methods 27 twin preg-nancy women with comorbidities were imaged with HASTE and True FISP sequences.All images were statistically analyzed in re-spect of imaging qualities and artifacts.MR signs of fetal brain were analysized.Results There were abnormal changes in brains in 7 of 27 cases.Both sequences could demonstrate the structures and lesions of the fatus.Imaging quality scores of HASTE were higher than that of True FISP,but with more respiratory blurring.Conclusion There might be varying abnormalities in central nervous system in twin pregnancy with comorbidities.Combining the demonstration abilities of HASTE and True FISP is needed when de-tecting fetus lesions,especially the brain.

Application of 3D-FlESTA Sequence in the Diagnosis of the Stenosis of Midbrain Aqueduct / 中国基层医药

Objective To explore the evaluation of three-dimensional fast imaging employing steady-state acquisition(3D-FIESTA) sequence in the diagnosis of non-tumorous midbrain aqueduct stenosis.Methods 48 patients with non-tumorous midbrain aqueduct stenosis were performed by conventional SE sequence and 3D-FIESTA sequence on a 1.5T superconductive MR unit.Then the advantage on showing aqueduct of midbrain foramen was retrospectively analyzed.Results The detecting rate of midbrain aqueduct stenosis was 98% (47/48) on 3D-FIESTA sequence and 79% (38/48) on conventional SE sequence,3D-FIESTA was more advanced on showing the aqueduct of midbrain(P <0.01).Conclusion The combination of 3D-FIESTA with MPR can clearly show the midbrain aqueduct stenosis,and be a new MRI examination way of obstructive hydrocephalus.