Diffusion-derived vessel density (DDVD) computed from a simple diffusion MRI protocol as a biomarker of placental blood circulation in patients with placenta accreta spectrum disorders: A proof-of-concept study.

OBJECTIVES: Increasing trend of PAS (placenta accreta spectrum disorders) incidence is a major health concern as PAS is associated with high maternal morbidity and mortality during cesarean section. Prenatal identification of PAS is crucial for delivery planning and patients management. This study aims to explore whether diffusion-derived vessel density (DDVD) computed from a simple diffusion MRI protocol differs in PAS from normal placenta. METHODS: We enrolled 86 patients with PAS disorders and 40 pregnant women without PAS disorders. Each patient underwent intravoxel incoherent motion (IVIM) MRI sequence with 11 b-values. Placenta diffusion-derived vessel density (DDVD-b0b50) was the signal difference between b = 0 and b = 50 s/mm2 images. DDVD(b0b50) A/N was calculated as [accreta lesion DDVD(b0b50)]/ [normal placenta DDVD(b0b50)]. The correlation between DDVD and gestational age was explored using Spearman rank correlation. Differences of DDVD(b0b50) A/N in patients with normal placentas and with PAS, and in patients with different subtypes of PAS were explored. RESULTS: DDVD was negatively correlated with gestational age (p = 0.023, r = -0.359) in patients with normal placentas. DDVD(b0b50) A/N was significantly higher in patients with PAS (median:1.16, mean: 1.261) than normal placenta (median:1.02, mean: 1.032, p < 0.001) and especially higher in patients with placenta increta (median:1.14, mean: 1.278) and percreta (median: 1.20, mean: 1.396, p < 0.001). CONCLUSION: As a higher DDVD indicates higher physiological volume of micro-vessels in PAS, this study suggests DDVD can be a potential biomarker to evaluate the placenta perfusion.

Sulfonated P-W modified nitrogen-containing carbon-based solid acid catalysts for one-pot conversion of cellulose to ethyl levulinate under water-ethanol medium.

Converting cellulose (Cel) into ethyl levulinate (EL) is one of the promising strategies for supplying liquid fuels. In this paper, the prepared sulfonated P-W-modified N-containing carbon-based solid acid catalyst (PWNCS), in which the Polyaniline (PANI) was employed as N and C precursors, successfully converted Cel into EL under the water-ethanol medium. The characterization results demonstrated that a tiny addition of P increased the Brønsted acid sites (BAS) content and defective WO3 provided the Lewis acid sites (LAS), meanwhile, the sulfonation process did not change the fundamental structure but introduced the sulfonic groups to dramatically increase the acidic content. Therefore, under optimized reaction conditions, PWNCS realized about 100% Cel conversion and 71.61% of EL yield, furthermore, the selectivity of EL reached 89.14%. In addition, the effect of water on the reaction pathway of Cel to EL over PWNCS was proposed. The addition of water generally resulted in the hydration of defective WO3 to reduce the LAS and increase BAS, which significantly inhibited the side reactions of retro-aldol condensation (RAC) and subsequent etherification reactions during Cel conversion and then improved the selectivity of EL.

Standard diffusion-weighted, diffusion kurtosis and intravoxel incoherent motion in differentiating invasive placentas.

PURPOSE: To investigate the diagnostic value of monoexponential, biexponential, and diffusion kurtosis MR imaging (MRI) in distinguishing invasive placentas. METHODS: A total of 53 patients with invasive placentas and 47 patients with noninvasive placentas undergoing conventional diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) were retrospectively enrolled. The mean, minimum, and maximum parameters including the apparent diffusion coefficient (ADC) and exponential ADC (eADC) from standard DWI, diffusion kurtosis (MK), and diffusion coefficient (MD) from DKI and pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) from IVIM were measured and compared from the volumetric analysis. Receiver operating characteristics (ROC) curve and logistic regression analyses were conducted to evaluate the diagnostic efficiency of different diffusion parameters for distinguishing invasive placentas. RESULTS: Comparisons between accreta lesions in patients with invasive placentas (AL) and lower 1/3 part of the placenta in patients with noninvasive placentas (LP) demonstrated that MD mean, D mean, and D* mean were significantly lower while ADC max and D max were significantly higher in invasive placentas (all p < 0.05). Multivariate analysis demonstrated that D mean, D max and D* mean differed significantly among all the studied parameters for invasive placentas. A combined use of these three parameters yielded an AUC of 0.86 with sensitivity, specificity, and accuracy of 84.91%, 76.60%, and 80%, respectively. CONCLUSION: The combined use of different IVIM parameters is helpful in distinguishing invasive placentas.

Research process, recap, and prediction of Chiari malformation based on bicentennial history of nomenclature and terms misuse.

There is an absent systematic analysis or review that has been conducted to clarify the topic of nomenclature history and terms misuse about Chiari malformations (CMs). We reviewed all reports on terms coined for CMs for rational use and provided their etymology and future development. All literature on the nomenclature of CMs was retrieved and extracted into core terms. Subsequently, keyword analysis, preceding and predicting (2023-2025) compound annual growth rate (CAGR) of each core term, was calculated using a mathematical formula and autoregressive integrated moving average model in Python. Totally 64,527 CM term usage was identified. Of these, 57 original terms were collected and then extracted into 24 core-terms. Seventeen terms have their own featured author keywords, while seven terms are homologous. The preceding CAGR of 24 terms showed significant growth in use for 18 terms, while 13, three, three, and five terms may show sustained growth, remain stable, decline, and rare in usage, respectively, in the future. Previously, owing to intricate nomenclature, Chiari terms were frequently misused, and numerous seemingly novel but worthless even improper terms have emerged. For a very basic neuropathological phenomenon tonsillar herniation by multiple etiology, a mechanism-based nosology seems to be more conducive to future communication than an umbrella eponym. However, a good nomenclature also should encapsulate all characteristics of this condition, but this is lacking in current CM research, as the pathophysiological mechanisms are not elucidated for the majority of CMs.

Diffusion kurtosis and intravoxel incoherent motion in predicting postpartum hemorrhage in patients at high risk for placenta accreta spectrum disorders.

Background: Placenta accreta spectrum (PAS) disorder encompasses a spectrum of pathologies, from placenta accreta to placenta percreta, which is usually associated with postpartum hemorrhage (PPH). Methods: This cross-sectional study enrolled 109 patients suspected of having PAS disorders based on previous ultrasound results or clinical risk factors from November 2018 to March 2022 in Sichuan Provincial People's Hospital. Of the 109 patients, 34 had PPH and 75 did not have PPH. Magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) was performed for each patient and the apparent diffusion coefficient (ADC) from DWI, perfusion fraction (f), pure diffusion coefficient (D), and pseudo-diffusion coefficient (D*) from IVIM, and mean diffusion kurtosis (MK) and mean diffusion coefficient (MD) from DKI were measured and compared. The correlation between the DWI parameters and estimated blood loss (EBL) during surgery was identified using correlation analysis. The diagnostic performance for predicting PPH was compared between the two methods. Results: The amount of bleeding during delivery was positively correlated with D [r=0.331, P<0.001, 95% confidence interval (CI): 0.170 to 0.477], D* (r=0.389, P<0.001, 95% CI: 0.207 to 0.527), f (r=0.222, P=0.02, 95% CI: 0.036 to 0.398), and MD (r=0.277, P=0.003, 95% CI: 0.108 to 0.439), but negatively correlated with MK (r=-0.280, P=0.003, 95% CI: -0.431 to -0.098). In predicting PPH, multivariate analyses showed the independent risk factors were placenta previa and D; the area under the curve (AUC) was 0.795 (95% CI: 0.711 to 0.878) when the two risk factors were combined together. Conclusions: IVIM and DKI parameters are correlated with EBL. The combined use of placenta previa and D are helpful for predicting PPH in patients at high risk of PAS disorders.

Longitudinal course of hyperintensity on diffusion weighted imaging in adult-onset neuronal intranuclear inclusion disease patients.

Background: High signals on diffusion weighted imaging along the corticomedullary junction (CMJ) have demonstrated excellent diagnostic values for adult-onset neuronal intranuclear inclusion disease (NIID). However, the longitudinal course of diffusion weighted imaging high intensities in adult-onset NIID patients has rarely been investigated. Methods: We described four NIID cases that had been discovered using skin biopsy and NOTCH2NLC gene testing, after diffusion weighted imaging exhibiting the distinctive corticomedullary junction high signals. Then using complete MRI data from NIID patients, we analyzed the chronological diffusion weighted imaging alterations of those individuals that had been published in Pub Med. Results: We discussed 135 NIID cases with comprehensive MRI data, including our four cases, of whom 39 had follow-up outcomes. The following are the four primary diffusion weighted imaging dynamic change patterns: (1) high signal intensities in the corticomedullary junction were negative on diffusion weighted imaging even after an 11-year follow-up (7/39); (2) diffusion weighted imagings were initially negative but subsequently revealed typical findings (9/39); (3) high signal intensities vanished during follow-up (3/39); (4) diffusion weighted imagings were positive at first and developed in a step-by-step manner (20/39). We discovered that NIID lesions eventually damaged the deep white matter, which comprises the cerebral peduncles, brain stem, middle cerebellar peduncles, paravermal regions, and cerebellar white matter. Conclusion: The longitudinal dynamic changes in NIID of diffusion weighted imaging are highly complex. We find that there are four main patterns of dynamic changes on diffusion weighted imaging. Furthermore, as the disease progressed, NIID lesions eventually involved the deep white matter.

Differentiation of placenta percreta through MRI features and diffusion-weighted magnetic resonance imaging.

OBJECTIVES: To identify whether parameters measured from diffusion kurtosis and intravoxel incoherent motion help diagnose placenta percreta. METHODS: We retrospectively enrolled 75 patients with PAS disorders including 13 patients with placenta percreta and 40 patients without PAS disorders. Each patients underwent diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI). The apparent diffusion coefficient (ADC), perfusion fraction (f), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), mean diffusion kurtosis (MK) and mean diffusion coefficient (MD) were measured by the volumetric analysis and compared. MRI features were also analyzed and compared. The receiver operating characteristic (ROC) curve and logistic regression analysis were used to evaluate the diagnostic efficiency of different diffusion parameters and MRI features for distinguishing placental percreta. RESULTS: D* was an independent risk factor from DWI for predicting placenta percreta with sensitivity of 73% and specificity of 76%. Focal exophytic mass remained as independent risk factor from MRI features for predicting placenta percreta with sensitivity of 72.7% and specificity of 88.1%. When the two risk factors were combined together, the AUC was the highest, 0.880 (95% CI 0.8-0.96). CONCLUSION: D* and focal exophytic mass were associated with placenta percreta. A combination of the 2 risk factors can be used to predict placenta percreta. CRITICAL RELEVANCE STATEMENT: A combination of D* and focal exophytic mass can be used to differentiate placenta percreta.

Association of MRI Features and Adverse Maternal Outcome in Patients With Placenta Accreta Spectrum Disorders After Abdominal Aortic Balloon Occlusion.

BACKGROUND: MRI features may be associated with adverse maternal outcome in patients with placenta accreta spectrum (PAS) disorders even with abdominal aortic balloon occlusion (AABO). PURPOSE: This study aimed to identify risk factors of MRI for association with adverse maternal outcome in patients with PAS disorders after AABO. STUDY TYPE: Retrospective. POPULATION: Clinical and MRI features of 80 patients were retrospectively reviewed from October 2016 to August 2021. A total of 40 patients had adverse maternal outcomes including intrapartum/peripartum bleeding >1000 mL and/or emergency hysterectomy after AABO. SEQUENCE: Half-Fourier acquisition single-shot turbo spin echo and gradient echo imaging True fast imaging with steady-state precession (True-FISP) at 1.5T MR scanner. ASSESSMENT: MRI features were evaluated by three radiologists and were tested for any association with adverse maternal outcome. STATISTICAL TESTS: Interobserver agreement was calculated with kappa (k) statistics. Association between MRI features and adverse maternal outcomes were evaluated by univariate and multivariate analyses. A nomogram was constructed based on the logistic regression. RESULTS: The interobserver agreement ranged from fair to substantial (k = 0.379-0.783). Multivariate analyses revealed that short cervical length (OR: 4.344), abnormal intraplacental vascularity (OR: 6.005), placental bulge (OR: 9.085), and myometrial interruption (OR: 9.550) were independent risk factors for adverse maternal outcomes. The combination of four risk factors together demonstrated the highest AUC of 0.851 (95% CI 0.769-0.933) with a sensitivity and specificity of 77.5% and 72.5%, respectively and then a nomogram composed of the above four risk factors was constructed to represent the probability of adverse maternal outcome. DATA CONCLUSION: The nomogram demonstrated the association between MRI features and patient's poor outcome after undergoing AABO and C-section delivery for PAS. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 3.

Prevalence and treatment of typical and atypical headaches in patients with Chiari I malformation: A meta-analysis and literature review.

OBJECTIVE: A meta-analysis was conducted to analyze the incidence of typical and atypical headaches and outcomes following various treatments in patients with Chiari I malformation. BACKGROUND: Headache is the most common symptom of Chiari malformation, which can be divided into typical and atypical subgroups to facilitate management. Much controversy surrounds the etiology, prevalence and optimal therapeutic approach for both types of headaches. METHOD: We identified relevant studies published before 30 July 2022, with an electronic search of numerous literature databases. The results of this study were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. RESULT: A total of 1913 Chiari malformation type I CIM patients were identified, 78% of whom presented with headache, within this group cephalgia was typical in 48% and atypical in 29% of patients, and migraine was the most common type of atypical headache. The ratio of typical/atypical headaches with international classification of headache disorders diagnosis was 1.53, and without international classification of headache disorders diagnosis was 1.56, respectively. The pooled improvement rates of typical headaches following conservative treatment, extradural decompression and intradural decompression were 69%, 88%, and 92%, respectively. The corresponding improvement rates for atypical headaches were 70%, 57.47%, and 69%, respectively. The complication rate in extradural decompression group was significantly lower than in intradural decompression group (RR, 0.31; 95% CI: 0.06-1.59, I2 = 50%, P = 0.14). Low reoperation rates were observed for refractory headaches in extradural decompression and intradural decompression groups (1%). CONCLUSION: The International Classification of Headache Disorders can assist in screening atypical headaches. extradural decompression is preferred for typical headaches, while conservative therapy is optimal for atypical headaches. A definite correlation exists between atypical headaches and Chiari Malformation Type I patients with higher prevalence than in the general population. Importantly, decompression is effective in relieving headaches in this particular patient population.

Radiomics analysis of T2 -weighted images for differentiating invasive placentas in women at high risks.

PURPOSE: To develop and validate an MRI-based radiomics model for differentiating invasive placentas in patients with high risks. METHODS: A total of 181 pregnant women suspected of placenta accreta spectrum (PAS) disorders and who underwent MRI for placenta evaluation were retrospectively enrolled. The data set was randomly divided into the training (n = 125; invasive = 63, noninvasive = 62) and test (n = 56; invasive = 28, noninvasive = 28) groups. Radiomics features were extracted from half-Fourier acquisition single-shot turbo spin echo (HASTE) and sagittal true fast imaging in steady-state precession (TRUFISP) sequences independently and mainly selected based on their correlations with invasive placentas to construct two radiomics signatures including HASTE-Radscore and TRUFISP-Radscore. Then, the predictive performance of radiomic signatures, clinical features, radiographic features, and their combination were evaluated. The model with the best predictive performance was validated with its discrimination ability, calibration, and clinical usefulness. RESULTS: Five radiomics features from HASTE and three radiomics features from TRUFISP were retained, respectively, for predicting invasive placentas. The combination of radiomics signatures and clinical features including prior cesarean delivery, placenta previa, and radiographic feature, the placental thickness resulted in the best discrimination ability, with area under the curve of 0.898 (95% confidence interval [CI] 0.844-0.9522) and 0.858 (95% confidence interval 0.7514-0.9655) in the training and test cohort, respectively. The combined model showed a significantly better area under the curve performance and clinical usefulness than independent clinical or radiographic model according to DeLong test (p < .05), net reclassification improvement and integrated discrimination improvement analysis (positive improvement) and decision curve analysis (higher net benefit). CONCLUSIONS: The T2 -weighted imaging MRI radiomics model could serve as a potential prenatal diagnosis tool for identifying invasive placentas in patients with high risks.

Correlation of placental thickness and placenta percreta in patients with placenta previa: findings from MRI.

INTRODUCTION: This study aimed to identify if placental thickness measured from MRI images correlated with placenta percreta in patients with placenta previa. METHODS: Placental thickness was retrospectively measured in 161 patients from July 2018 to August 2020. The measurements were performed at the thickest part of the placenta in the lower uterine segment on the mid-sagittal plane MR images by two independent radiologists. Intraoperative and pathologic findings were the standard of reference. Univariate and multivariate analyses were performed to identify the relationship between clinical features, placental thickness, and placenta percreta. The predictive ability of placental thickness was demonstrated using receiver operating characteristic curve analysis. RESULTS: Placental thickness in patients with placenta percreta was significantly higher than in patients with placenta increta, placenta accreta, and normal placentas (p < 0.05). Multivariate analysis revealed that placental thickness was the only independent risk factor for placenta percreta. The cutoff value of placental thickness was 4.35 cm for differentiating placenta percreta in patients with placenta previa. DISCUSSION: Patients with placenta percreta had the highest placental thickness. Placental thickness was correlated with placenta percreta.

The MRI estimations of placental thickness and cervical length correlate with postpartum hemorrhage (PPH) in patients with risk for placenta accreta spectrum (PAS) disorders.

INTRODUCTION: This study aims to identify whether placental thickness and cervical length measured by MRI correlate with postpartum hemorrhage (PPH) in patients at high risk for placenta accreta spectrum (PAS) disorders. METHODS: The placental thickness and cervical length of 200 patients from October 2017 to October 2021 were retrospectively measured. The mid-sagittal plane of the placentas was measured by 2 independent radiologists using MRI. Partial correlation analysis was used to characterize the correlation between placental thickness, cervical length and estimated blood loss during surgery. The correlation between clinical features, placental thickness, cervical length and PPH was evaluated with univariate and multivariate analyses. A nomogram was constructed based on the logistic regression. RESULTS: Placental thickness was positively correlated with the estimated blood loss during delivery, while cervical length had a negative correlation with it, based on the adjustment for gestational age. Multivariate analyses revealed that prior cesarean section, placenta previa, increased placental thickness(≧4.35 cm) and short cervical length（< 3.05 cm） were independent risk factors for PPH. When the 4 risk factors were combined together, the AUC was the highest, 0.773 (95%CI 0.707-0.840). DISCUSSION: Placental thickness and cervical length correlated with PPH. The nomogram constructed based on prior cesarean section, placenta previa, placental thickness and cervical length can be used to recognize patients with a higher risk of PPH.

Diffusion and perfusion MRI parameters in the evaluation of placenta accreta spectrum disorders in patients with placenta previa.

OBJECTIVES: To evaluate the placental function by monoexponential, biexponential, and diffusion kurtosis MR imaging (MRI) in patients with placenta previa. METHODS: A total of 62 patients with placenta accreta spectrum (PAS) disorders and 11 patients with normal placentas were retrospectively enrolled, who underwent conventional diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI). The apparent diffusion coefficient (ADC) and exponential ADC (eADC) from standard DWI, mean kurtosis (MK), and diffusion coefficient (MD) from DKI, and pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) from IVIM were measured and compared from the volumetric analysis. RESULTS: Comparisons between patients with PAS disorders and patients with normal placentas demonstrated that MD mean, D mean, and D* mean values in patients with PAS disorders were significantly higher than those in patients with normal placentas (p < 0.05). Comparisons between patients with accreta, increta, and percreta, and patients with normal placentas showed that the D mean was significantly higher in patients with placenta increta and percreta than in patients with normal placentas (p < 0.05). CONCLUSION: The accreta lesions in PAS disorders had deceased cellularity and increased blood movement. The alteration of placental cellularity was more prominent in placenta increta and percreta.

Standard diffusion-weighted, diffusion kurtosis and intravoxel incoherent motion MR imaging of the whole placenta: a pilot study of volumetric analysis.

Background: Using magnetic resonance imaging (MRI) to explore the changes in microvascular perfusion fraction and the heterogeneity of the placenta during pregnancy. Methods: We retrospectively reviewed 24 patients with normal pregnancies who underwent standard diffusion-weighted, diffusion kurtosis, and intravoxel incoherent motion MRI. The mean, minimum and maximum parameters including the apparent diffusion coefficient (ADC) and exponential ADC (eADC) from standard diffusion-weighted imaging (DWI), the diffusion coefficient (MD) and diffusion kurtosis (MK) from diffusion kurtosis imaging (DKI), and the pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f) from intravoxel incoherent motion MR imaging (IVIM) were calculated from the whole placenta volumetric analysis and correlated with gestational age (GA) and volume of the placenta. Results: A significant positive correlation was found between eADC mean, eADC max, MK mean, MK max, the volume of the whole placenta, and GA, and a negative correlation was found between ADC mean, ADC min, MD min, D mean, D min, D* min and GA. The f mean and MK max values positively correlated with the volume of the whole placenta. Conclusions: eADC mean, eADC max, MK mean, MK max values increased with GA, while ADC mean, ADC min, MD min, D mean, D min, D* min decreased with GA. Secondly, the f mean and MK max also increased with placental volume. These results suggest the potential of diffusion and perfusion parameters to evaluate the placenta during its development using different DWI models.

Monoexponential, biexponential and diffusion kurtosis MR imaging models: quantitative biomarkers in the diagnosis of placenta accreta spectrum disorders.

BACKGROUND: To investigate the diagnostic value of monoexponential, biexponential, and diffusion kurtosis MR imaging (MRI) in differentiating placenta accreta spectrum (PAS) disorders. METHODS: A total of 65 patients with PAS disorders and 27 patients with normal placentas undergoing conventional DWI, IVIM, and DKI were retrospectively reviewed. The mean, minimum, and maximum parameters including the apparent diffusion coefficient (ADC) and exponential ADC (eADC) from standard DWI, diffusion kurtosis (MK), and mean diffusion coefficient (MD) from DKI and pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) from IVIM were measured from the volumetric analysis and compared between patients with PAS disorders and patients with normal placentas. Univariate and multivariated logistic regression analyses were used to evaluate the value of the above parameters for differentiating PAS disorders. Receiver operating characteristics (ROC) curve analyses were used to evaluate the diagnostic efficiency of different diffusion parameters for predicting PAS disorders. RESULTS: Multivariate analysis demonstrated that only D mean and D max differed significantly among all the studied parameters for differentiating PAS disorders when comparisons between accreta lesions in patients with PAS (AP) and whole placentas in patients with normal placentas (WP-normal) were performed (all p < 0.05). For discriminating PAS disorders, a combined use of these two parameters yielded an AUC of 0.93 with sensitivity, specificity, and accuracy of 83.08, 88.89, and 83.70%, respectively. CONCLUSION: The diagnostic performance of the parameters from accreta lesions was better than that of the whole placenta. D mean and D max were associated with PAS disorders.

Preliminary study on the diagnostic value of cardiac magnetic resonance feature tracking for malignant ventricular arrhythmias in non-ischemic dilated cardiomyopathy.

Background: Patients with nonischemic dilated cardiomyopathy (NIDCM) and malignant ventricular arrhythmia (MVA) often have a poor prognosis and a high risk of sudden cardiac death. Although the diagnosis of MVA is straightforward by electrocardiogram (ECG), the underlying abnormalities of ventricular mechanics in these patients are unknown. This study aims to preliminarily explore the value of cardiac magnetic resonance feature tracking (CMR-FT) for MVA in dilated cardiomyopathy. Methods: In this retrospective study, patients with NIDCM who met inclusion criteria were divided into an MVA group and a non-MVA group (included from January 2018 to September 2021). The interobserver agreement of myocardial strain parameters, including global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS), were tested. The GLS, GCS, GRS, left ventricular ejection fraction (LVEF), Tpeak-Tend interval on ECG and brain natriuretic peptide (BNP) were compared between groups. Single-factor and multifactor receiver operating characteristic (ROC) curve analyses were conducted to calculate the area under the ROC curve (AUC), cut-off point, sensitivity, and specificity of these parameters in predicting MVA in NIDCM. Results: A total of 161 NIDCM patients were included (54 in the MVA group). GLS, GCS, and GRS had good interobserver agreement (all intraclass correlation coefficients >0.80). The absolute GLS and GCS, GRS and LVEF were lower in the MVA group than the non-MVA group (P<0.001), Tpeak-Tend and BNP were higher (P<0.001). Single-factor ROC curve analysis showed that GLS, GCS and GRS had certain diagnostic value for MVA (AUC =0.795, 0.802, and 0.754, respectively). Among them, GCS had higher sensitivity and specificity (GCS 0.796/0.776, GLS 0.778/0.757, GRS 0.741/0.692). Multifactor ROC curve analysis showed the combination of GLS and GCS (AUC =0.810), the combination of GCS and GRS (AUC =0.802), the combination of GLS and GRS (AUC =0.787), the combination of GLS, GCS, and GRS (AUC =0.810). Conclusions: The three-dimensional myocardial strain parameters (especially GLS and GCS) measured by CMR-FT had certain diagnostic value and could reflect the underlying abnormality of ventricular mechanics of NIDCM with MVA.

Correlation of placental thickness and PAS disorders: findings from MRI.

OBJECTIVE: To identify if placental thickness measured from MRI images correlates with placenta accreta spectrum (PAS) disorders. METHODS: Placental thickness of 245 patients was retrospectively measured from October 2016 to March 2020. The measurement was made at the thickest portion of the placenta on the mid-sagittal plane of the placenta from MRI by two independent radiologists. Surgical report and pathology of the delivered placenta were used as a reference standard. Association between clinical features, placental thickness, and PAS disorders was evaluated with univariate and multivariate analyses. The inter-reader and intra-reader reproducibility of the measurements and receiver operating characteristic curve analysis were also performed. RESULTS: Placental thickness was significantly higher in patients with PAS disorders (3.45 cm) than that in patients without PAS disorders (2.90 cm) (p < 0.05). Multivariate analyses revealed that prior cesarean section, placenta previa, and placental thickness > 4 cm were independent risk factors for PAS disorders. The inter-reader and intra-reader reproducibility of placental thickness measurement were 0.979 (95% CI 0.960-0.989) and 0.981 (95% CI 0.9640-0.990), respectively. CONCLUSION: The reproducibility of the measurement made from MRI images was high between two radiologists. Patients with PAS disorders had increased placental thickness. Placental thickness > 4 cm correlated with PAS disorders.

Strepchazolins A and B: Two New Alkaloids from a Marine Streptomyces chartreusis NA02069.

Two new alkaloids, strepchazolins A (1) and B (2), together with a previously reported compound, streptazolin (3), were isolated from a marine actinomycete, Streptomyces chartreusis NA02069, collected in the Coast of Hainan Island, China. The structures of new compounds were determined by extensive NMR, mass spectroscopic and X-ray crystallographic analysis, as well as modified Mosher's method. Compound 1 showed weak anti-Bacillus subtilis activity with the MIC value of 64.0 µM, and weak inhibitory activity against acetylcholinesterase (AChE) in vitro with IC50 value of 50.6 µM, while its diastereoisomer, Compound 2, is almost inactive.