Utilization of Multi-Parametric Quantitative Magnetic Resonance Imaging in the Early Diagnosis of Duchenne Muscular Dystrophy.

BACKGROUND: It is challenging to diagnose suspected Duchenne muscular dystrophy (DMD) patients in the very early stage of the disease. More evidence is needed to demonstrate the potential of quantitative MRI (qMRI) in precisely identifying patients before substantial physical decline occurs. PURPOSE: To assess the early diagnostic performance of multi-parametric qMRI for DMD patients, and the ability to identify DMD patients with mild functional decline. STUDY TYPE: Prospective. SUBJECTS: One hundred and forty DMD subjects (9.0 ± 2.2 years old), 24 male healthy controls (HCs) (9.2 ± 2.5 years old). FIELD STRENGTH/SEQUENCE: 3.0 T/3-point Dixon, T1-mapping, and T2-mapping. ASSESSMENT: qMRI measurements (fat fraction [FF], T1, and T2) of 11 thigh muscles (rectus femoris [RF], vastus lateralis [VL], vastus intermedius, vastus medialis, gracilis, sartorius, adductor longus, adductor magnus [AM], semitendinosus, semimembranosus, biceps femoris long head [BFLH]) on the right side were conducted. NorthStar ambulatory assessment (NSAA) score used to evaluate the function of DMD patients and divided them into three subgroups: mild (76-100 score), moderate (51-75 score), and severe (0-50 score) functional decline. STATISTICAL TESTS: Independent t-test, ANOVA analysis, and receiver operating characteristic (ROC) curves. A P-value <0.05 was considered statistically significant. RESULTS: Compared with HCs, FF and T2 were significantly higher in the group of all DMD patients, while T1 was significantly lower. The combination of T1 and T2 in RF, VL, AM, and BFLH achieved excellent area under curve (AUCs) (0.967-0.992) in differentiating five DMD patients without abnormal fat infiltration from HCs. Overall, T2 reached higher AUCs than FF and T1 in distinguishing DMD with mild functional decline from HCs, whereas FF achieved higher AUCs than T1 and T2 in distinguishing three DMD subgroups with functional decline. DATA CONCLUSION: Multi-parametric qMRI demonstrate effective diagnostic capabilities for DMD patients in the early stage of the disease, and can identify patients with mild physical decline. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

Risk model and factors for prediction of response to neoadjuvant chemotherapy in patients with advanced gastric cancer-a two-center cohort study.

OBJECTIVE: Due to inconsistency in neoadjuvant chemotherapy (NACT) response in advanced gastric cancer (GC), the indications remain the source of controversy. This study focused on identifying factors related to NACT chemosensitivity and providing the best treatment for GC cases. METHODS: Clinical data in 867 GC cases treated with neoadjuvant chemotherapy were downloaded from two medical centers between January 2014 and December 2020, and analyzed by logistic regression and the least absolute shrinkage and selection operator (LASSO) for identifying potential factors that predicted NACT response and might be incorporated in constructing the prediction nomogram. RESULTS: After the inclusion and exclusion criteria were applied, totally 460 cases were enrolled, among which, 307 were males (66.74%) whereas 153 were females (33.26%), with the age of 24-77 (average, 59.37 ± 10.60) years. Consistent with RECIST standard, 242 patients were classified into effective group (PR or CR) while 218 were into ineffective group (PD or SD), with the effective rate of 52.61%. In training set, LASSO and logistic regression analysis showed that five risk factors were significantly associated with NACT effectiveness, including tumor location, Smoking history, T and N stages, and differentiation. In terms of our prediction model, its C-index was 0.842. Moreover, calibration curve showed that the model-predicted results were in good consistence with actual results. Validation based on internal and external validation sets exhibited consistency between training set results and ours. CONCLUSIONS: This study identified five risk factors which were significantly associated with NACT response, including smoking history, clinical T stage, clinical N stage, tumor location and differentiation. The prediction model that exhibited satisfying ability to predict NACT effectiveness was constructed, which may be adopted for identifying the best therapeutic strategy for advanced GC by gastrointestinal surgeons.

[Diffusion tensor imaging map of anterior cruciate ligament contrasted with MRI in healthy adults].

OBJECTIVE: To measure anterior cruciate ligament (ACL) by diffusion tensor imaging (DTI), combined with ACL half quantitative measurement magnetic resonance imaging (MRI) method as the contrast, and to preliminarily investigate the feasibility of DTI for ACL. METHODS: The ACLs of 31 healthy volunteers were scanned with ordinary MRI and DTI. At ordinary MRI map, sagittal ACL-tibial angle, coronal ACL-tibial angle, Blumensaat line-ACL angle, angle of inclination of the intercondylar roof, and ACL-tibial insertion site were measured. As for DTI analysis of ACL, ACL was divide to 5 portions, namely 1(st), 2(nd), 3(rd), 4(th), 5(th), and all fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of every portion were recorded and repeated. RESULTS: The sagittal ACL-tibial angle, coronal ACL-tibial angle, Blumensaat line-ACL angle, angle of inclination of the intercondylar roof, and ACL-tibial insertion site were 53.00°±2.46°, 52.42°±5.15°, 12.67°±5.71°, 39.41°±2.64°, (24.90±2.84)%, respectively. FA values of different portions were 0.611±0.042, 0. 618±0.051, 0.596±0.045, 0.566±0.059, and 0.497±0.072. ADC values of 1(st)-5(th) portion were (1.068±0.216), (1.128±0.268), (1.189±0.197), (1.455±0.423), and (1.779±0.384)× 10(-3) mm(2)/s. The correlation coefficient of sagittal ACL-tibial angle and the FA value of 2(nd) and 3(rd) portion was -0.568 and -0.429. The correlation coefficient of Blumensaat line-ACL angle and the FA value of 1(st) and 4(th) portion was -0.507 and -0.633. The correlation coefficient of ACL-tibial insertion site and the FA value of 4(th) portion was -0.593, all with statistical significance. FA and ADC values of all portions in both team's ACL didn't have significant difference (P>0.05), but had obvious correlation. CONCLUSION: DTI can be used to effectively evaluate the orientation and connection of ACL, having good contrast virtue with ACL half quantitative MRI measurement. It may provide more profound ACL information for clinicians, and it is of great significance for the further research and large sample data base of ACL pathology.