MRI susceptibility weighted imaging for monitoring vertebral development trajectory in second-third trimester fetuses / 中华放射学杂志

Objective:To measure the morphological parameters of the fetal vertebral centrum ossification centers (COC) in the second-third trimester using MRI susceptibility weighted imaging (SWI), and to explore the growth and development trajectory of the vertebrae.Methods:Fetus in the second-third trimester with normal vertebrae development were prospectively and continuously included in Shandong Provincial Hospital Affiliated to Shandong First Medical University from December 2015 to December 2021, and the SWI scanning of fetal spine was performed. The following morphometric parameters of the C4, T6, L3, S1 vertebrae COC were measured, including sagittal diameter, transverse diameter, height, cross-sectional area and volume. The linear and nonlinear regression analysis was used to derive the best-fit curve for each parameters and gestational age.Results:A total of 112 fetuses were recruited with gestatonal age 21-39 (29.4±3.9) weeks, including 30 cases of C4, 58 cases of T6, 92 cases of L3, 62 cases of S1. Fetal spine in utero with global curvature was kyphosis, presenting two primary curves (thoracic and sacral kyphosis). The morphological parameters sagittal diameter, transverse diameter, height, cross-sectional area and volume of C4 followed the quadratic polynomial rule during 25 to 38 weeks (R 2=0.938, 0.943, 0.952, 0.957, 0.982). During 21 to 38 weeks, the sagittal diameter, transverse diameter and height of the T6 followed the exponential growth pattern (R 2=0.915, 0.923, 0.849) and the growth of the area and volume followed the quadratic polynomial growth pattern (R 2=0.943, 0.961). The L3 followed the quadratic polynomial rule during 21 to 39 weeks (R 2=0.910, 0.916, 0.914, 0.942, 0.948) The sagittal diameter, transverse diameter and height of the S1 followed the linear growth pattern (R 2=0.905, 0.911, 0.922) and the area and volume followed the quadratic polynomial growth pattern (R 2=0.930, 0.964) during 23 to 39 weeks. Conclusions:The growth and development of C4, T6, L3 and S1 COC of fetus in the second-third trimester has a good correlation with gestational age. The growth of fetal vertebral COC in the early stage is slow, but with the growth of gestational age, the growth rate of vertebral bodies accelerates.

Imaging features and clinical outcome in fetus with coronal cleft vertebrae / 中华放射学杂志

Objective:To explore the MRI features of fetal coronal cleft vertebrae, and to compare the efficacy of MRI and ultrasound in the diagnosis of fetal coronal cleft vertebrae, and to analyze the outcome of fetal coronal cleft vertebrae.Methods:From September 2019 to June 2021, 40 fetuses suspected of fetal vertebral deformities by ultrasound were retrospectively collected in Shandong Provincial Hospital Affiliated to Shandong University, who were diagnosed as coronal cleft vertebrae after MRI examination. Five cases of induced labor and 14 cases lost to follow-up were excluded, and 21 fetuses who underwent MRI after delivery were finally included. The gestational weeks were 25-34 (29.1±2.6) weeks, and there were 19 males and 2 females. Fetal spine MRI includes susceptibility weighted imaging (SWI) and T 2-true fast imaging with steady-state (True-FISP). The MRI features and outcome of fetal coronal cleft vertebrae were explored. The image quality scores of SWI, T 2-True-FISP and ultrasound were compared with Friedman test and Wilcoxon signed-rank test. The diagnostic accuracy of fetal coronal cleft vertebrae of SWI, T 2-True-FISP and ultrasound was calculated. Cochran test was used to compare the efficiency of 3 kinds of images, and the modified McNemar test was used for pairwise comparison between groups. Results:There were 10 cases of single and 11 cases of multiple fetal coronal cleft vertebrae, 16 cases of simple lumbar vertebrae, 2 cases of simple thoracic vertebrae, and 3 cases of thoracolumbar vertebrae. The common SWI features of 21 cases show longitudinal strip or dot high signal on the sagittal plane, and transverse fissure like high signal on axial plane. Anterior part of vertebral body was larger than posterior part in 19 cases of them. The image quality scores of SWI, T 2-True-FISP and ultrasound were 4 (3, 4), 2 (2, 2), 2 (2, 2), and the difference was statistically significant in general (χ2=34.24, P<0.001). Pairwise comparison showed that the image quality of SWI was better than those of T 2-True-FISP and ultrasound ( Z=-4.04, P<0.001; Z=-4.11, P<0.001), and there was no statistically significant difference between T 2-True-FISP and ultrasound ( Z=-0.58, P=0.388). The diagnostic accuracy of SWI, T 2-True-FISP and ultrasound was 100% (21/21), 66.7% (14/21), 47.6% (10/21). The diagnostic accuracy of SWI was better than those of T 2-True-FISP and ultrasound (χ2=5.14, P=0.008; χ2=9.09, P<0.001), and there was no statistically significant difference between T 2-True-FISP and ultrasound (χ2=0.75, P=0.194). MRI showed that coronal cleft vertebrae disappeared in all 21 fetuses after birth, including 1 case of syringomyelia and 1 case of fatty filum terminal. Conclusions:MRI, especially SWI, plays an important role in the diagnosis of fetal coronal cleft vertebrae. Fetal coronal cleft vertebrae disappeared in the follow-up after birth, which proved to be a normal physiological variation from the radiographic perspective.

The application values of MR quantitative susceptibility mapping in differentiation between knee meniscus degeneration and tear / 中华放射学杂志

Objective:To evaluate the feasibility and the application values of quantitative susceptibility mapping (QSM) for the assessment of meniscal injury and in distinguishing meniscus degeneration and tears.Methods:The clinical and imaging data of 70 patients suspected of meniscus injury and scheduled for arthroscopy in Shandong Medical Imaging Research Institute, Cheeloo College of Medicine, Shandong University from November 2019 to June 2020 were analyzed retrospectively. Thirty age-and sex-matched healthy subjects were also examined as controls. All subjects received knee joint QSM and routine MR imaging. According to the results of arthroscopy, the patients was divided into meniscus degeneration and meniscus tear groups, respectively. The conventional MR was evaluated by two radiologists. The meniscus injury area was delineated on the original QSM magnitude images (the central area of the posterior corner of the lateral meniscus was selected in the healthy controls) and mapped to the corresponding QSM maps, and the magnetic susceptibility values were measured. Kruskal-Wallis H test was used to analyze the magnetic sensitivity values of meniscal degeneration, meniscal tear and healthy control groups; and Bonferroni was used to correct the pairwise comparison. ROC curve was established to evaluate the threshold and efficacy of magnetic susceptibility value in the diagnosis of meniscal tear. The results were compared with those of conventional MRI. Results:The magnetic susceptibility values of meniscus of healthy controls, meniscal degeneration and meniscal tear groups were (0.035±0.016)ppm, -0.031(-0.040,-0.005)ppm, and(-0.122±0.115)ppm, respectively, with significant difference found among the three groups (χ2=44.419, P<0.05). The magnetic susceptibility values of meniscus of healthy controls was significantly higher than those of meniscus degeneration patients and meniscus tear patients (χ2=-23.843, -48.253, P<0.05). The magnetic susceptibility values of meniscus of meniscus tear group was significant lower than those of meniscus degeneration group (χ2=-24.410, P<0.05). Taking magnetic susceptibility values of -0.062 5 ppm as threshold, the area under the ROC curve for the diagnosis of meniscal tears was 0.949, with the sensitivity as 87% and the specificity as 100%. The sensitivity and specificity of conventional MRI in the diagnosis of meniscal tears were 86.8% and 87.5%, respectively. Conclusion:QSM can quantitatively evaluate meniscus injury and can be used as an effective supplement method to conventional MRI, which is helpful to improve the diagnosis of meniscus tear.

Feasibility of prenatal MRI in the diagnosis of fetal external ear developmental malformation / 中华放射学杂志

Objective:To discuss the feasibility of prenatal MRI in evaluating fetal auricle developmental malformation and atresia of external auditory canal.Methods:Fifteen pregnant women (aged from 22 to 40 years old, mean age 31.3±5.2 years old) with fetal external ear developmental malformation suspected by ultrasound underwent MR scanning between November 2017 and May 2019. All of them were singleton. The gestational age ranged from 23 weeks to 35 weeks, with an average of (27.5±3.5) weeks. The sensitivity, specificity and accuracy of MRI and ultrasound in the diagnosis of fetal auricle malformation and atresia of external auditory canal were calculated and compared, using postnatal follow-up as the gold standard. Fisher exact test was used to compare the efficacy of MRI and ultrasound in diagnosing atresia of external auditory canal.Results:A total of 30 fetal external ears were detected in 15 fetuses, without auricle absence. Totally 19 external ears with developmental malformation were confirmed by postnatal follow-up, including 19 ears with auricle malformation and 15 ears with external auditory canal atresia. The accuracy of MRI and ultrasound in the diagnosis of auricle malformation was both 100% (19/19). For the diagnosis of external auditory canal atresia, the sensitivity, specificity and accuracy of MRI and ultrasound were 93.3% (14/15), 75.0% (3/4), 89.5% (17/19) and 33.3% (5/15), 25.0% (1/4), 31.6% (6/19), respectively. The sensitivity and accuracy of MRI in the diagnosis of atresia of external auditory canal were significantly higher than those of ultrasound, with statistically significant difference ( P=0.004, 0.001). Conclusion:MRI plays an important role in the diagnosis of fetal external ear developmental malformation, which can be used as an effective supplement to ultrasound, especially for the diagnosis of external auditory atresia.

Evaluation of the neurodevelopment outcome of prenatally diagnosed periventricular pseudocysts using MRI / 中华放射学杂志

Objective:To evaluate alterations of periventricular pseudocysts (PVPC) on MRI before and after birth, and to assess the prognosis.Methods:We retrospectively analyzed the data of 67 cases that were diagnosed with PVPC on prenatal MRI, of which 24 cases were lost to follow-up, 2 died after birth. A total of 41 surviving fetuses were included in this prognosis study. The gestational ages in this group were between 23 and 39 weeks, with an average of (33±3) weeks.All the subjects underwent brain MRI examinations and Gesell Developmental Scale (GDS) testing between 0-3 years of age. According to the location of cysts and with or without other intracranial and extracranial malformations (dilated ventricles orcerebella medulla, hypoxic-ischemic encephalopathy, TORCH virus infection, corporal hypoplasia, chromosomal malformations and nodular sclerosis) , the patients were divided into four groups: isolated connatal cysts, connatal cysts with additional findings,isolated subependymal pseudocysts, and subependymal pseudocysts with additional findings.The MR images were independently reviewed by two radiologists blinded to the clinical information. Intraclass correlation efficient (ICC) was used to analyze the consistency between the two reviewers.Chi-square test was used to compare the location of cysts (single/bilateral), the number of cyst cavities (single/multi-chamber), and other abnormalities in the connatal cyst group and subependymal cyst group. The mean anteroposterior diameter and mean height of cysts between the connatal cyst group and subependymal cyst group were compared by independent sample t-test.The ANOVA test was used to compare the differences in GDS outcomes among the groups. Multiple comparisons were conducted using the LSD test. Results:Inter-observer agreements between the two radiologists were good for the collected data (all ICC>0.75). Eleven isolated connatal cysts and 7 connatal cysts with additional findings became smaller or disappeared, and all had good prognosis. Of the 14 isolated subependymal cysts, 12 became smaller or disappeared, 2 had no change in size, and 13 had good prognosis. The subependymal cysts with additional findings group included 9 cases: 6 became smaller or disappeared, only 3 showed no apparent changes, and 7 had an abnormal outcome. Subependymal cysts with additional findings were significantly reduced and patients demonstrated significant differences compared with the those with isolated subependymal cysts in the development quotients (DQ) of adaptability, large movements, fine movements, personal social interaction, and language DQ ( P all<0.05). DQ between patients with isolated connatal cysts and isolated subependymal cysts was comparable ( P all>0.05). When associated with additional findings, connatal cysts and subependymal cysts could induce significant different DQ outcome ( P all<0.05). Conclusions:Isolated PVPC usually become smaller or disappeared and have a benign presentation after birth, whereas patients with subependymal cysts with additional findings usually have a poor prognosis. Connatal cysts usually have a good prognosis.

Susceptibility weighted imaging in evaluation of the fetal vertebra and vertebral anomalies / 中华放射学杂志

Objective To explore the advantages of susceptibility weighted imaging (SWI) in depiction of normal fetal vertebra and vertebral anomalies.Methods This prospective study was approved by our institutional review board, and written informed consent was obtained from every participant, Fifty-eight pregnant women (gestation age 22 to 39 weeks, average 29 ± 3 weeks) who were suspected of carrying babies with vertebral anomalies by ultrasound screening underwent 1.5 T fetal spine MRI[including half-fourier acquisition single-shot turbo spin-echo(HASTE),true fast imaging with steady-state(True FISP) and SWI sequences]. MR images were reviewed for their quality by two radiologists independently. The image scores in HASTE, True FISP and SWI were compared by using Kruskal-Wallis test and Mann-Whitney U test. Three segments (cervical, thoracic and lumbosacral segments, respectively) of 15 fetuses were, at random, collected to compare among HASTE,True FISP and SWI and then evaluated by ANOVA analysis.The diagnostic accuracy of the three sequences among 32 cases with follow-up results was calculated respectively and compared by using Chi-square test. Results There was statistical differences among three sequences(χ2=50.685,P<0.05).The scores of SWI was higher than that of True FISP, and the scores of True FISP was higher than that of HASTE in the evaluation of the fetal vertebra(P all<0.05).The differences among cervical,thoracic and lumbosacral segments on True FISP and HASTE showed significant difference statistically (P all<0.05), also the image quality of cervical segment could not meet the requirement of clinical diagnosis. The image quality of SWI was favorable clinically and no statistical difference among three segments was found(P>0.05).A total of 32 fetal vertebral anomalies were identified by follow-up after birth including hemivertebra (n=14), fusion of vertebrae (n=1), butterfly vertebra (n=1), multiple vertebral malformations(n=9),spinal bifida(n=5),caudal regression syndrome(n=2).The diagnostic accuracy of SWI, True FISP and HASTE was 93.75% (30/32), 56.25% (18/32) and 37.50% (12/32) respectively.The diagnostic accuracy of SWI was the best compared to that of True-FISP and HASTE(χ2=10.083,20.017;P<0.01). Conclusion SWI proved to be the optimal technique in depiction of fetal vertebra and vertebral anomalies than True FISP and HASTE,especially in depiction of cervical vertebra.

The optimal visualization of brachial plexus with utilization of nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation imaging MR neurography and initial dignostic application / 中华放射学杂志

Objective To assess the optimal visiualization capacity of brachial plexus with three-dimensional nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation imaging (3D SHINKEI), exploring the feasibility of preliminary diagnostic value on brachial plexus diseases. Methods MRI scans were performed on 24 healthy volunteers with no history of brachial plexus injury, and 46 patients whose outcomes of lesions had been verified as post-ganglionic brachial plexus injuries by surgery or clinical follows-up . The scan series consist 3D SHINKEI, STIR in the coronal plane as well as DW-MRN in the axial plane using a 3.0 T MR system. The source and post-processed images of 3D SHINKEI and DW-MRN were scored according to the optimal visibility on brachial plexus, in the meanwhile, contrast-to-noise ratio of the original images in the 3D SHINKEI and STIR sequences were calculated separately. Two radiologists blindly compared the detection rate of positive brachial plexus injuries between 3D SHINKEI and STIR in 46 patients. And then analyze the outcomes by means of Kappa test, Mann-Whitney test , independent sample t test, and Chi-square test. Results Post-ganglionic brachial plexus showed high intensity in the 3D SHINKEI sequence. In the 24 healthy volunteers, the scores by the two radiologists were 3.6 ± 0.6, 3.5 ± 0.6, 3.0 ± 0.2, 2.9 ± 0.1, respectively. There was statistical difference between the two sequences (Z=2.667,P=0.008,P<0.05). And the Kappa was 0.8 and 0.6 with favorable consistency. The CNR of 3D SHINKEI and STIR were 0.61 ± 0.07, 0.42 ± 0.03 (t=12.78, P=0.001, P<0.05). The positive detection rates of post-ganglionic brachial plexus injuries on 3D SKINKEI and STIR were, 78.3%, 52.2%(χ2=9.421, P<0.05). Conclusions 3D SHINKEI sequence demonstrates robust visibility consistently and can clearly display the structures and signals of post-ganglionic abnormality, compared with DW-MRN and STIR. This technique can be helpful to provide more complementary information to further confirm the diagnosis of brachial plexus injuries.