MRI study on the influence of lumbosacral vertebral body and disc factors on lumbar lordosis in children.

PURPOSE: To evaluate the influence of vertebral and disc wedging on the contribution of lumbar lordosis and the change of disc thickness before and after walking based on MRI. METHODS: Cross-sectional study. A total of 96 normally developing children, aged 5.7 ± 3.0 years old, 55 boys and 41 girls. They were divided into 3 groups: Pre-walking group, Walking group, and Post-walking group. PARAMETERS: lumbar lordosis Angle (LLA), the sum of the lumbar disc wedge Angle (∑D), the sum of the lumbar vertebral body wedge Angle (∑B), disc height (DH). RESULTS: (1) LLA, ∑D, ∑B, and DHL1-S1 were 33.2 ± 8.7°, 14.1 ± 8.6°, 11.9 ± 8.6°, and 6.9 ± 1.2 mm, 7.6 ± 1.4 mm, 8.2 ± 1.6 mm, 8.9 ± 1.7 mm, 8.5 ± 1.8 mm. (2) The difference in LLA values between the Pre-walking and the Post-walking group was statistically significant. DH were significantly different among the three groups. (3) In the Post-walking group, LLA value of girls was significantly higher than that of boys, and DHL3 - 4 and DHL4 - 5 values of girls were significantly lower than that of boys. (4) Age had a low positive correlation with LLA and ∑D and a moderate to strong positive correlation with DH; LLA showed a moderate positive correlation with ∑D, and a low positive correlation with ∑B and DH. CONCLUSION: Age and walking activity are the influencing factors of lumbar lordosis and disc thickening. Walking activity can significantly increase lumbar lordosis, and age is the main factor promoting lumbar disc thickening. DHL4-5 was the thickest lumbar intervertebral disc with the fastest intergroup thickening. Disc wedging contributes more to lumbar lordosis than vertebral wedging.

Diagnosis of cervical lymph node metastasis with thyroid carcinoma by deep learning application to CT images.

Introduction: The incidence of thyroid diseases has increased in recent years, and cervical lymph node metastasis (LNM) is considered an important risk factor for locoregional recurrence. This study aims to develop a deep learning-based computer-aided diagnosis (CAD) method to diagnose cervical LNM with thyroid carcinoma on computed tomography (CT) images. Methods: A new deep learning framework guided by the analysis of CT data for automated detection and classification of LNs on CT images is proposed. The presented CAD system consists of two stages. First, an improved region-based detection network is designed to learn pyramidal features for detecting small nodes at different feature scales. The region proposals are constrained by the prior knowledge of the size and shape distributions of real nodes. Then, a residual network with an attention module is proposed to perform the classification of LNs. The attention module helps to classify LNs in the fine-grained domain, improving the whole classification network performance. Results: A total of 574 axial CT images (including 676 lymph nodes: 103 benign and 573 malignant lymph nodes) were retrieved from 196 patients who underwent CT for surgical planning. For detection, the data set was randomly subdivided into a training set (70%) and a testing set (30%), where each CT image was expanded to 20 images by rotation, mirror image, changing brightness, and Gaussian noise. The extended data set included 11,480 CT images. The proposed detection method outperformed three other detection architectures (average precision of 80.3%). For classification, ROI of lymph node metastasis labeled by radiologists were used to train the classification network. The 676 lymph nodes were randomly divided into 70% of the training set (73 benign and 401 malignant lymph nodes) and 30% of the test set (30 benign and 172 malignant lymph nodes). The classification method showed superior performance over other state-of-the-art methods with an accuracy of 96%, true positive and negative rates of 98.8 and 80%, respectively. It outperformed radiologists with an area under the curve of 0.894. Discussion: The extensive experiments verify the high efficiency of the proposed method. It is considered instrumental in a clinical setting to diagnose cervical LNM with thyroid carcinoma using preoperative CT images. The future research can consider adding radiologists' experience and domain knowledge into the deep-learning based CAD method to make it more clinically significant. Conclusion: The extensive experiments verify the high efficiency of the proposed method. It is considered instrumental in a clinical setting to diagnose cervical LNM with thyroid carcinoma using preoperative CT images.

Comparison of diffusion-weighted imaging mono-exponential mode with diffusion kurtosis imaging for predicting pathological grades of clear cell renal cell carcinoma.

PURPOSE: To evaluate the role of diffusion kurtosis imaging (DKI1) in the characterization of clear cell renal cell carcinoma (ccRCC2) compared with standard diffusion-weighted imaging (DWI3). METHODS: 89 patients with histologically proven ccRCC were evaluated by DKI and DWI on a 3-T scanner. All ccRCCs were classified as grade 1-4 according to the Fuhrman classification system. The apparent diffusion coefficient (ADC4), fractional anisotropy (FA5), mean diffusivity (MD6), mean kurtosis (MK7), axial kurtosis (Ka8) and radial kurtosis (Kr9) values were recorded. The differences in DWI and DKI parameters were evaluated by independent-sample t test and a receiver operating characteristic (ROC10) analysis was performed. The DeLong test was performed to compare the ROCs. RESULTS: Compared to normal renal parenchyma, ADC and MD values of ccRCC decreased and MK, Ka, and Kr values increased (p < 0.05). ADC and MD values of ccRCC decreased with the increase in pathological grade, while MK, Ka, and Kr values were increased (p < 0.05). ADC could discriminate G1 vs G3, G1 vs G4, G2 vs G3, G2 vs G4, and G3 vs G4 (p < 0.05) except for G1 vs G2 (p > 0.05). Ka and Kr could discriminate G1 vs G2, G1 vs G3, G1 vs G4, G2 vs G4, and G3 vs G4 (p < 0.05) except for G2 vs G3 (p > 0.05). MD and MK could discriminate G1 vs G2, G1 vs G3, G1 vs G4, G2 vs G3, G2 vs G4, and G3 vs G4 (p < 0.05). The AUC of MK was the highest. The DeLong test showed that there were significant differences regarding ROCs between ADC/MK, ADC/Ka, ADC/Kr in grading G1/G2, and ADC/MK, MK/Ka in grading G3/G4 (p < 0.05). CONCLUSION: DKI was superior compared to the mono-exponential mode of DWI in grading ccRCC.

Accurate diagnosis of fetal cleft lip/palate by typical signs of magnetic resonance imaging.

OBJECTIVE: This study aims to evaluate the accuracy of magnetic resonance imaging (MRI) in diagnosing orofacial clefts and proposes specific signs for determining the type of cleft. METHODS: Pregnant women in whom fetal facial malformations are suspected by ultrasonography (US) underwent 1.5 T MRI. The accuracy of the prenatal US and MRI diagnosis was compared with the postnatal findings. RESULTS: A total of 71 fetuses were included in the final analysis, which comprised of 35 cases of isolated cleft lip, six cases of cleft lip and alveolus, 21 cases of cleft lip and palate, four cases of isolated cleft palate, and five normal fetuses. MRI was more sensitive than US (MRI 100%, US 77.5%; Fisher's exact test: MRI vs US P=0.000). The accuracy of MRI for all types was 100%. Specific signs (Inverted T, L/anti-L, U, and "Notch" signs) were proposed, indicating the normal hard, unilateral cleft, bilateral cleft, and cleft soft palates, respectively, which can facilitate the identification of different types of cleft palates. CONCLUSION: MRI can accurately diagnose the type of cleft based on typical signs, which can serve as a definite diagnostic modality and an effective supplement of US.

Normal development of costal element ossification centers of sacral vertebrae in the fetal spine: a postmortem magnetic resonance imaging study.

PURPOSE: This postmortem magnetic resonance imaging (MRI) study of the fetal spine aimed to describe the timing of appearance, shape, volume, and relative positions of the S1-S3 costal element ossification centers (CEOCs). METHODS: We obtained sagittal 3D dual-echo steady-state with water excitation T2 images of the entire spine in 71 fetuses (gestational ages (GAs), 17-42 weeks). Computed tomography and histological examinations were performed on two fetal specimens (GAs, 21 and 30 weeks) to validate the MR images. The presence/absence of each sacral CEOC was recorded according to the GA. CEOC volume was measured. We analyzed the CEOC position relative to the vertebral column and ilium. RESULTS: The S1, S2, and S3 CEOCs first appeared at 23, 22, and 29 weeks, respectively. The S1 and S2 CEOCs could be detected in all fetuses with GAs of ≥ 30 weeks and ≥ 35 weeks, respectively, while the S3 CEOCs were variably present until term. The percentages of detection of the S1 and S2 CEOCs were significantly greater than that of the S3 CEOCs at each GA. At S1 and S2, the CEOC volume increased exponentially with GA. The relative positions of the S1 and S2 CEOCs, but not the S3 CEOCs, significantly correlated with GA (P < 0.001). CONCLUSION: We have described the timeline of appearance as well as the volume and position of the S1-S3 CEOCs in the fetal spine on postmortem MRI according to GA.

Diffusion Tensor Imaging of Tibial and Common Peroneal Nerves in Patients With Guillain-Barre Syndrome: A Feasibility Study.

BACKGROUND: The development of a noninvasive, objective, and accurate method to assess peripheral nerve disorders in Guillain-Barre syndrome (GBS) is of clinical significance. Diffusion tensor imaging (DTI) has been used to evaluate some peripheral nerve disorders. PURPOSE: To investigate the feasibility of DTI in evaluating the peripheral nerve disorders in patients with GBS. STUDY TYPE: Case control. SUBJECTS: Twenty GBS patients and 16 healthy volunteers. FIELD STRENGTH/SEQUENCE: 3.0T, T1 WI-SE, T2 WI-SPAIR, DTI; electrophysiology. ASSESSMENT: MRI data were analyzed by two radiologists blindly and independently. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusion coefficient (AD), and radial diffusion coefficient (RD) values of tibial nerve (TN) and common peroneal nerve (CPN) were recorded. Motor nerve conduction velocity (MCV) and motor nerve conduction amplitude of TN and CPN were recorded. STATISTICAL TESTS: Intraclass correlation coefficient (ICC), t-test, receiver-operating characteristic (ROC), and area under the curve (AUC) analysis, Pearson correlation coefficient. RESULTS: The FA and AD values of TN and CPN in the GBS group were significantly lower and the ADC and RD values were higher than those in the controls (P <0.05). The AUC of the FA values (0.970 for TN and 0.927 for CPN) were higher than that of the ADC, AD, and RD values. FA and AD values were positively correlated and ADC, RD values were negatively correlated with MCV and motor nerve conduction amplitude, respectively (P <0.05). The correlations between FA value and electrophysiology parameters were the highest. DATA CONCLUSION: DTI quantitative parameters could evaluate the disorders of peripheral nerves in patients with GBS. A moderate correlation was observed between DTI and electrophysiology parameters. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:1356-1364.

Effect and mechanism of lentivirus-mediated silencing of TPX2 gene on proliferation and apoptosis of human hepatoma cells.

This study aimed to investigate the role and mechanism of action of targeting protein for Xklp2 (TPX2) in liver cancer, we compared TPX messenger RNA (mRNA) expression in liver cancer tissue samples and adjacent normal liver tissue samples as well as in human liver cancer cell lines and nonmalignant cell line by quantitative reverse transcription polymerase chain reaction (qRT-PCR). TPX2 gene was silenced in HepG2 cells by transfection with the lentiviral vector expressing TPX2-targeting short hairpin RNA (shRNA), and the knockdown efficiency was evaluated by RT-qPCR. Cell proliferation, apoptosis as well as protein level of c-Myc, cyclin D1, caspase-3, phosphorylated glycogen synthase kinase-3ß (p-GSK-3ß), and ß-catenin in HepG2 cells were evaluated before and after the TPX2 knockdown. Wnt/ß-catenin signaling pathway was inhibited by treatment with 20 µM of XAV-939 or activated by treatment with 20 mM of LiCl. We found that TPX2 mRNA level was significantly increased in liver cancer tissue samples and cell lines comparing to noncancerous counterparts (P < 0.05). TPX2 knockdown significantly reduces TPX2 expression (P < 0.01), cell proliferation (P < 0.05), protein level of c-Myc and cyclin D1 (P < 0.01), activation of Wnt/ß-catenin signaling in HepG2 cells (P < 0.01) while increasing cell apoptosis (P < 0.01). Treatment with XAV-939 significantly reduced HepG2 cell proliferation (P < 0.05) while increasing cell apoptosis (P < 0.01). Treatment with LiCl significantly attenuated the antiproliferative and apoptosis-promoting effect of TPX2 knockdown on HepG2 cells (P < 0.05). Lentivirus-mediated silencing of TPX2 gene could inhibit proliferation and induce apoptosis in hepatoma cells by inhibiting Wnt signaling pathway and regulating cyclin and apoptosis-related proteins.

Normal development of sacrococcygeal centrum ossification centers in the fetal spine: a postmortem magnetic resonance imaging study.

PURPOSE: To describe the temporal pattern of the appearance of the S1-Co1 centrum ossification centers (COCs) and provide reference data for the S1-S5 COCs and sacral length at various gestational ages (GAs). METHODS: Postmortem magnetic resonance imaging (MRI) was performed on 71 fetuses (GA, 17-42 weeks) using the 3D dual-echo steady-state with water excitation T2 sequence in the sagittal plane. To confirm the reliability of this sequence, the MRI data were compared with the CT and histologic data obtained from two fetuses (GAs, 21 and 30 weeks). The presence or absence of each sacrococcygeal COC was recorded. Sacral length and S1-S5 COC height, sagittal diameter, transverse diameter, cross-sectional area, and volume were measured. RESULTS: All fetuses showed S1-S3 COCs by 17 weeks, S4 COCs by 19 weeks, and S5 COCs by 28 weeks. The S4, S5, and Co-1 COCs were visualized in 70 (98.59%), 51 (71.83%), and 21 (29.58%) fetuses, respectively. Sacral length, height, sagittal, and transverse diameters increased linearly, while cross-sectional area and volume increased exponentially with advancing GA. Mean growth rates of the sagittal and transverse diameters, cross-sectional area, and volume, but not of height, significantly differed among the S1-S5 vertebrae. CONCLUSION: We have presented the timing of appearance of individual sacrococcygeal COCs and the age-specific, normative MRI reference values for sacral length and the morphometric parameters of the sacral COCs, which are of clinical importance in the diagnosis of congenital sacral abnormalities and skeletal dysplasia.

Intravoxel Incoherent Motion (IVIM) Diffusion-Weighted Imaging (DWI) in Patients with Liver Dysfunction of Chronic Viral Hepatitis: Segmental Heterogeneity and Relationship with Child-Turcotte-Pugh Class at 3 Tesla.

BACKGROUND: Few studies focused on the region of interest- (ROI-) related heterogeneity of liver intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI). The aim of the study was to evaluate the differences of liver IVIM parameters among liver segments in cirrhotic livers (chronic viral hepatitis). MATERIAL AND METHODS: This was a retrospective study of 82 consecutive patients with chronic liver disease who underwent MRI examination at the Jinan Infectious Diseases Hospital between January 2015 and December 2016. IVIM DWI (seven different b values) was performed on a Siemens 3.0-T MRI scanner. Pure molecular diffusion (D), pseudodiffusion (D ∗), and perfusion fraction (f) in different liver segments were evaluated. RESULTS: f, D, and D ∗ were different among the liver segments (all p < 0.05), indicating heterogeneity in IVIM parameters among liver segments. f was consistently higher in Child-Turcotte-Pugh (CTP) class A compared with CTP class B + C (p < 0.01). D and D ∗ were higher in CTP class A compared with CTP class B + C (p < 0.05). In patients with mean f value of >0.29, the AUC was 0.88 (95% CI: 0.81-0.96), with 86.8% sensitivity and 81.8% specificity for predicting CTP class A from CTP class B + C. CONCLUSION: Liver IVIM could be a promising method for classifying the severity of segmental liver dysfunction of chronic viral hepatitis as evaluated by the CTP class, which provides a noninvasive alternative for evaluating segmental liver dysfunction with accurate selection of ROIs. Potentially it can be used to monitor the progression of CLD and LC in the future.

Fetal cerebral lobes development between 20 and 28 weeks gestational age: a postmortem MR study.

To investigate the fetal cerebral lobes development between 20 and 28 weeks gestational age, 36 fetus specimen without CNS abnormality, with 4 fetuses in each gestation week, were scanned with 3.0T MR. Lobular parameters were measured, including the parenchyma thickness of the frontoparietal and the temporal lobes, the margin length of frontoparietal, the insula and the temporal lobes, the Sylvian fissure and the perimeter of hippocampus, on the plane perpendicular to the longitudinal axis of hippocampus body across the base of cerebral peduncle. The relative value of parenchyma thickness and the lobes' length ratios to the same side hemisphere were calculated and their correlation with gestational weeks was analyzed. All measured parameters were positively correlated with gestational age. No significant tendency was found for relative value of the parenchyma thickness (P>0.05). The temporal lobe length ratio increased while the frontoparietal ratio decreased before 24 weeks GA and then the two reversed. The Sylvian fissure length ratio increased (P<0.001) and the hippocampus decreased (P<0.001) throughout this period. In conclusion, the early fetal cerebrum lobes developed asynchronously during this period, the 24 weeks GA could be a turning point for cerebrum development pattern changing from primitive to mature.

MRI findings in 6 cases of children by inadvertent ingestion of diphenoxylate-atropine.

PURPOSE: Compound diphenoxylate (diphenoxylate-atropine) poisoning can cause toxic encephalopathy in children, and magnetic resonance imaging (MRI) of the brain in this condition has not been reported. This study is to analyze brain MRI findings and to investigate the relations between MRI features and possible pathophysiological changes in children. METHODS: Six children accidentally swallowed compound diphenoxylate, 4 males, 2 females, aged 20-46 months, average 33 months. Quantity of ingested diphenoxylate-atropine was from 6 to 30 tablets, each tablet contains diphenoxylate 2.5mg and atropine 0.025 mg. These patients were referred to our hospital within 24h after diphenoxylate-atropine ingestion, and underwent brain MRI scan within 24-72 h after emergency treatment. The characteristics of conventional MRI were analyzed. RESULTS: These pediatric patients had various symptoms of opioid intoxication and atropine toxicity. Brain MRI showed abnormal low signal intensity on T1-weighted images (T1WI) and abnormal high signal intensity on T2-weighted images (T2WI) and fluid-attenuated inversion recovery (FLAIR) imaging in bilateral in all cases; abnormal high signal intensity on T1WI, T2WI and FLAIR in 4 cases. Encephalomalacia was observed in 3 cases during follow-up. CONCLUSION: In the early stage of compound diphenoxylate poisoning in children, multiple extensive edema-necrosis and hemorrhagic-necrosis focus were observed in basic nucleus, pallium and cerebellum, these resulted in the corresponding brain dysfunction with encephalomalacia. MRI scan in the early stage in this condition may provide evidences of brain impairment, and is beneficial for the early diagnosis, treatment and prognosis assessment.

Sequential treatment of superior vena cava syndrome caused by of non-small cell carcinoma lung cancer (NSCLC) with vascular stenting and iodine-125 implantation.

Feasibility and efficacy of sequentially performed endovascular stenting and Iodine-125 brachytherapy for malignant superior vena cava syndrome (SVCS) were evaluated. Thirty-four patients with malignant SVCS caused by NSCLC underwent sequential treatment of endovascular stenting and Iodine-125 brachytherapy. SVCS was diagnosed in all patients by CT images or vena-cavography. Pathology diagnosis was acquired by image guided biopsy. Endovascular stent placement was performed as first-line treatment for symptom relief. CT-guided Iodine-125 seed implantation performed 24hr after stenting. Clinical end points were resolution of symptoms and local efficacy of primary malignancy regression. Symptom relief rate was >90% after 24hr and 97% after 3 months. No migration of seeds or restenosis occurred in any patient. The local efficacy (defined as either partial or complete response) was 53%, 79%, 88% and 74% after 1, 3, 6 and 12 months, respectively. Mean SVCS-free survival time was 305 days (range 120-960 days). Two patients were still alive at the time of this writing, Thirty-one died from progression and one died from acute heart disease. Sequentially performed endovascular stenting and Iodine-125 brachytherapy provides a safe and effective alternative for malignant SVCS caused by NSCLC.