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Objective:To investigate the value of the 8-channel eye surface phased array coil in improving image quality and demonstrating ocular masses on 3.0 T MR scanner.Methods:From July 2018 to January 2020, the data of orbital MRI in 692 patients with ocular masses on 6 medical centers were prospectively collected. The patients were simple randomly assigned into 8-channel eye surface phased array coil group (413 patients) or 8-channel head phased array coil group (279 patients), with the same MRI sequences. The signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated in orbital anatomy structures and masses (eyelid mass, intraocular mass, lacrimal mass and orbital mass). The image quality scores including motion artifact, mass margin, the relationship between the mass and adjacent structures, and overall image quality were recorded. The differences of image quality between the two groups were compared by two independent sample t-test or Wilcoxon rank test. Results:The SNR and CNR were higher in eye surface coil group than those in head coil group ( P<0.05). The scores of ocular movement artifacts were higher in head coil group than those in surface coil group ( P<0.05). The scores of intraocular mass margin, the relationship between the mass and adjacent structures, and overall image quality were higher in surface coil group than those in head coil group ( P<0.001). There were no significant differences in mass margin, the relationship between the mass and adjacent structures, and overall image quality scores of eyelid, lacrimal gland, and orbital mass between the two groups ( P>0.05). Conclusion:3.0 T MR scanner combined with the 8-channel eye surface phased array coil can improve the SNR and CNR of orbital MR images, the demonstration of the intraocular mass margin and the relationship between the mass and adjacent structures.
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Objective:To explore the value of multi-parametric MRI for thyroid gland in differentiating benign and malignant thyroid nodules.Methods:From December 2018 to May 2020, 78 patients with 91 post-surgically pathologically confirmed thyroid nodules were enrolled in Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. For each patient, the following MRI findings were obtained including the nodules′ location, size, shape, margin, signal intensity, cystic change, degree and pattern of contrast enhancement, involvement of surrounding structure, and ADC values. The time-intensity curve (TIC) were plotted and subtyped based on dynamic contrast enhancement MRI. The MRI findings between the benign and malignant thyroid nodules were compared using Mann-Whitney U test, χ 2 test or Fisher exact test. Multiple logistic regression analysis was used to select independent predictive variables and build a combined model, and the ROC curve was used to evaluate the diagnostic performance of each MRI finding and the combined model. Results:Between the benign and malignant thyroid nodules, the significant differences were found in size, shape, margin, presence of cystic changes, T 1WI signal intensity, ADC value, enhancement homogeneity, TIC subtypes and presence of thyroid capsule involvement ( P<0.05). Multivariate logistic analysis showed that ill-defined margin (OR=77.61), no presence of cystic changes (OR=36.11) and difference between TIC subtypes (OR=83.41) were independent predictive variables, and the area under the ROC curve (AUC) was 0.879, 0.788, and 0.751, respectively. The AUC, sensitivity and specificity of the combined model were 0.977, 0.986, and 0.904, respectively. Conclusions:Thyroid multi-parametric MRI derived findings can be used for the differential diagnosis of benign and malignant nodules. Combined with the independent risk factors with ill-defined margin, no presence of cystic changes, TIC of type plateau or washout, the diagnostic model has a higher diagnostic efficiency.
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Objective To explore the value of small surface coil combined with three-dimensional double-echo steady-state with water excitation (3D-DESS-WE) sequence in displaying mandibular nerves and their branches. Methods The maxillofacial regions of 52 volunteers were scanned unilaterally by a small surface coil combined with 3D-DESS-WE sequence. According to the Gray's anatomy atlas,MPR and CPR was done according to the anatomic position of mandibular nerve and the branches,the signal characteristics of the nerves and neighboring structures were analyzed. The displaying rate of the mandibular nerves and their branches were evaluated.The image quality and display of the nerve were subjectively scored. The signal intensity(SI) of the nerve and adjacent lateral pterygoid muscle were measured. The signal intensity ratio(SIR) of mandibular nerve/lateral pterygoid muscle (SIRN/M) was calculated. Results Compared with the muscles, the nerve showed iso-signal intensity. The subjective scores for all small coil 3D-DESS-WE images were 3.02 ± 0.82. The displaying rates of V3 trunk,anterior trunk,buccal nerve, posterior trunk,inferior alveolar nerve and lingual nerve were all 100%. V3 posterior trunk,inferior alveolar nerve and lingual nerve showed the best quality scores,which were all about 3 points,and the SIRN/M were about 1. The auricular temporal nerve and masseter muscle nerve were also basically satisfied. The displaying rate of mylohyoid muscle nerve,medial pterygoid nerve and lateral pterygoid nerve was low. Conclusion Small surface coil combine with 3D-DESS-WE sequence performed high-quality in mandibular nerves and their branches MR imaging using MPR,CPR post-processing technology,which are suitable for clinical application.
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Objective To evaluate the clinical application of 15-channel phased-array head coil and 6-channel dS Flex M surface coil in MRI imaging of temporomandibular joint.Methods Totally 50 patients were randomly equally assigned into two groups, of whom, one group used a 15-channel phase-array head coil for MRI scanning, and the other applied a 6-channel dS Flex M surface coil. The same regions of interest were set up to measure and analyze the signal to noise ratio (SNR)and contrast to noise ratio (CNR)of each region respectively.SPSS 19.0 software was used for quantitative analysis. Results The head coil had the SNR and the CNR higher than those of the surface coil.The head coil and Flex surface coil had the imaging diagnosis rates being 95.83% and 91.67% respectively,and there was no significant difference between them(P>0.05). Conclusion Both phase-array head coil and dS Flex M surface coil can be used for temporomandibular joint MRI imaging, and it's suggested that conventional imaging be executed with dS Flex M surface coil and functional imaging be implemented with head coil.
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Objective To explore the value of small surface coil combine with three-dimensional fast imaging with steady state precession and fat-suppression (3D-FISP-FS) sequence in displaying intra-parotid facial nerves segment and parotid ducts.Methods The parotid regions of 18 healthy volunteers who were excluded any parotid diseases were scanned by head&neck coil (36 sides) and 4 cm small surface coil (32 sides) combined with 3D-FISP-FS sequence prospectively. The obtained original images were treated through MIP, MPR and CPR, The MRI signal characteristics of parotid region structure, the subjective score of image quality, the signal intensity ratio (SIR) of facial nerve/parotid tissue (SIR N) and parotid duct/parotid tissue (SIRD) was calculated, and the displaying rates of the facial nerves and parotid ducts were observed. Wilcoxon matched-samples signed rank sum test was used to compare the scores of head&neck coil and small coil 3D-FISP-FS sequence images, paired t test was used to compare SIRN, SIRD of the two groups, Chi-square test was used to compare of the displaying rate of the facial nerves and parotid ducts in two groups. Results Eighteen volunteers were successfully performed MRI scan of parotid gland. On 3D-FISP-FS sequence images, the parotid gland was showed slightly low signal intensity, muscle tissue was showed medium signal intensity, the vessels were showed slightly high or high signal, parotid segment of facial nerve was showed tortuous line-like high signal intensity, and parotid duct was showed curve high signal intensity, lymph nodes were showed kidney shaped, oval or spindle shaped high signal intensity structures. The subjective scores for head and neck coil and coil images were (2.0 ± 0.9) and (1.5 ± 0.7) respectively, and the difference was statistically significant (Z=-2.714, P=0.007), image quality of small coil group was better than that of head and neck coil group. The SIRN of the two groups was 1.7±0.8 and 2.1± 1.2 respectively, and the SIRD was 1.8±0.7 and 2.5±1.7 respectively, which showed a statistically significant difference between the two groups (t value was 2.978, 2.427 respectively, P value was 0.006, 0.031 respectively).All facial nerve trunks could be displayed by head and neck coil and small coil. On head and neck coil images, 25 sides of temporofacial truck, 15 sides of cervicofacial truck, 17 sides of temporofacial branches, 11 sides of cervicofacial branches, 16 sides of the parotid duct could be displayed. On small coil images, 30 sides of temporofacial truck, 28 sides of cervicofacial truck, 26 sides of temporofacial branches, 23 sides of cervicofacial branches, 27 sides of the parotid duct could be displayed, which showed a statistically significant difference (P<0.05). Conclusion Small surface coil performed better in parotid MR imaging with 3D-FISP-FS sequence than that of head and neck coil, which can simultaneous clearly display the trunk and branches of the intra-parotid facial nerves and parotid ducts.
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A total of 15 adult male (2 cases of normal, 3 cases of benign prostatic hyperplasia, 3 cases of Prostatic cancer, 4 cases of obstructive azoospermia and 3 cases of hemospermia) were evaluated of their prostates and seminal tracts with magnetic resonance(MR) imaging using an endorecta1 surface coi1. On T1W1, the prostatic capsule, periprostatic venous plexus and neurovascular bundle were clearly defined. The zonal anatomy and internal structure of the prostate were clearly visualized on T2W1. The invasion of cancer into the prostatic capsule or the neurovascular bundle could be defined. More of these anatomical depiction, we found some other possible pathophysiologic process such as inhomogeneous signal intensity of seminal plasma in hemospermia and wolffian remnants in vasal agenesis Our results show the value of MR imaging with endorectal surface coil in the evaluation of morphology and pathologic process of the prostate and seminal tract.