Tectonic and orbital forcing of the South Asian monsoon in central Tibet during the late Oligocene.

The modern pattern of the Asian monsoon is thought to have formed around the Oligocene/Miocene transition and is generally attributed to Himalaya-Tibetan Plateau (H-TP) uplift. However, the timing of the ancient Asian monsoon over the TP and its response to astronomical forcing and TP uplift remains poorly known because of the paucity of well-dated high-resolution geological records from the TP interior. Here, we present a precession-scale cyclostratigraphic sedimentary section of 27.32 to 23.24 million years ago (Ma) during the late Oligocene epoch from the Nima Basin to show that the South Asian monsoon (SAM) had already advanced to the central TP (32°N) at least by 27.3 Ma, which is indicated by cyclic arid-humid fluctuations based on environmental magnetism proxies. A shift of lithology and astronomically orbital periods and amplified amplitude of proxy measurements as well as a hydroclimate transition around 25.8 Ma suggest that the SAM intensified at ~25.8 Ma and that the TP reached a paleoelevation threshold for enhancing the coupling between the uplifted plateau and the SAM. Orbital short eccentricity-paced precipitation variability is argued to be mainly driven by orbital eccentricity-modulated low-latitude summer insolation rather than glacial-interglacial Antarctic ice sheet fluctuations. The monsoon data from the TP interior provide key evidence to link the greatly enhanced tropical SAM at 25.8 Ma with TP uplift rather than global climate change and suggest that SAM's northward expansion to the boreal subtropics was dominated by a combination of tectonic and astronomical forcing at multiple timescales in the late Oligocene epoch.

Liquid-solid ratio during hydrothermal carbonization affects hydrochar application potential in soil: Based on characteristics comparison and economic benefit analysis.

Returning straw-like agricultural waste to the field by converting it into hydrochar through hydrothermal carbonization (HTC) is an important way to realize resource utilization of waste, soil improvement, and carbon sequestration. However, the large-scale HTC is highly limited by the large water consumption and waste liquid pollution. Here, we propose strategies to optimize the liquid-solid ratio (LSR) of HTC, and comprehensively evaluate the stability, soil application potential, and economic benefits of corn stover-based hydrochar under different LSRs. The results showed that the total amount of dissolved organic carbon of hydrochars increased by 55.0% as LSR reducing from 10:1 to 2:1, while the element content, thermal stability, carbon fixation potential, specific surface area, pore volume, and functional group type were not obviously affected. The specific surface area and pore volume of hydrochar decreased by 61.8% and 70.9% as LSR reduced to 1:1, due to incomplete carbonization. According to the gray relation, hydrochar derived at LSR of 10:1 and followed by 2:1 showed greatest relation degree of 0.80 and 0.70, respectively, indicating better soil application potential. However, reducing LSR from 10:1 to 2:1 made the income of single process production increased from -388 to 968 ¥, and the wastewater generation decreased by 80%. Considering the large-scale application of HTC in fields for farmland improvement and environmental remediation, the comprehensive advantages of optimized LSR will be further highlighted.

Neoadjuvant chemotherapy followed by radical trachelectomy versus upfront abdominal radical trachelectomy for patients with FIGO 2018 stage IB2 cervical cancer.

OBJECTIVE: To explore the optimal fertility-sparing treatment for stage IB2 cervical cancer. We compared the outcomes of neoadjuvant chemotherapy (NACT) followed by radical trachelectomy (RT) with those of upfront abdominal RT (ART). METHODS: This is a retrospective study with prospectively collected data between August 2015 and July 2019. Patients with IB2 cervical cancer who desired fertility preservation underwent NACT followed by RT, or upfront ART, per their choice. RESULTS: This study included 51 patients, of which, 16 patients underwent NACT followed by RT and 35 patients chose upfront ART. Fertility was preserved in 12 (75.0%) and 27 (77.1%) patients from the NACT and upfront ART groups, respectively. Incidence rates of intraoperative (0% versus 3.7%) and postoperative complications (25.0% versus 48.1%) of the NACT group were lower compared to the upfront ART group (P=NS). Eleven (91.7%) patients in NACT group and 17 (63.0%) patients in upfront ART groups received adjuvant chemotherapy after surgery. The median follow-up, and 5-year recurrence-free survival rates of the NACT-RT and upfront ART groups were 56 and 61 months, and 83.3% and 96.3%, respectively (P=NS). The recurrence rate was higher in patients with tumor reduction <50% after NACT than that in patients with tumor reduction >50% (66.7% versus 0%, P < 0.05). Tumor reduction <50% was the only independent predictor of recurrence in patients who underwent NACT before RT. CONCLUSIONS: NACT followed by RT could be a feasible fertility-sparing option for selected patients with 1B2 cervical cancer. The NACT group had a relatively higher recurrence rate and fewer complications compared to the upfront ART group, albeit without statistical significance. Patients with tumor regression >50% after NACT could be ideal candidates for RT after NACT.

Multidecadally resolved polarity oscillations during a geomagnetic excursion.

Polarity reversals of the geomagnetic field have occurred through billions of years of Earth history and were first revealed in the early 20th century. Almost a century later, details of transitional field behavior during geomagnetic reversals and excursions remain poorly known. Here, we present a multidecadally resolved geomagnetic excursion record from a radioisotopically dated Chinese stalagmite at 107-91 thousand years before present with age precision of several decades. The duration of geomagnetic directional oscillations ranged from several centuries at 106-103 thousand years before present to millennia at 98-92 thousand years before present, with one abrupt reversal transition occurring in one to two centuries when the field was weakest. These features indicate prolonged geodynamo instability. Repeated asymmetrical interhemispheric polarity drifts associated with weak dipole fields likely originated in Earth's deep interior. If such rapid polarity changes occurred in future, they could severely affect satellites and human society.

A triage strategy in advanced ovarian cancer management based on multiple predictive models for R0 resection: a prospective cohort study.

OBJECTIVE: To present the surgical outcomes of advanced epithelial ovarian cancer (AEOC) since the implementation of a personalized approach and to validate multiple predictive models for R0 resection. METHODS: Personalized strategies included: 1) Non-invasive model: preoperative clinico-radiological assessment according to Suidan criteria with a predictive score for all individuals. Patients with a score 0-2 were recommended for primary debulking surgery (PDS, group A), or otherwise were counseled on the choices of PDS, neoadjuvant chemotherapy (NAC, group B) or staging laparoscopy (S-LPS). 2) Minimally invasive model: S-LPS with a predictive index value (PIV) according to Fagotti. Individuals with a PIV <8 underwent PDS (group C) or otherwise received NAC (group D). Intraoperative assessment (with Eisenkop, peritoneal cancer index [PCI], and Aletti scores) and surgical results were prospectively collected. RESULTS: Between September 2015 and August 2017, 161 pathologically confirmed epithelial ovarian cancer patients were included. A total of 52 (32.3%) patients had a predictive score of 0-2, and 109 (67.7%) patients had a score ≥3. Among these individuals, 41 (25.5%) patients received S-LPS. Finally, 110 (68.3%) patients underwent PDS (A+C), and 51 (31.7%) patients received NAC (B+D). The R0 resection rates in PDS and NAC patients were 56.4% and 60.8%, respectively. The area under the curve (AUC) of Suidan criteria was 0.548 for group (A+C). The AUC of Fagotti score was 0.702 for group C. The AUC of Eisenkop, PCI, and Aletti scores were 0.808, 0.797, and 0.524, respectively. CONCLUSION: The Suidan criteria were not effective in these AEOC patients. S-LPS was helpful in decision-making for PDS and should be endorsed in the future.

18F-FDG PET/CT can predict chemosensitivity and proliferation of epithelial ovarian cancer via SUVmax value.

PURPOSE: This study aimed to explore the clinical and prognostic significance of 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in epithelial ovarian cancer (EOC). METHODS: We retrospectively investigated 48 EOC patients who underwent preoperative 18F-FDG PET/CT and primary cytoreductive surgery at our hospital between January 2010 and June 2015. None of these patients received neoadjuvant chemotherapy. PET/CT parameters including the maximum and average standardized uptake value (SUVmax, SUVavg), the metabolic tumor volume (MTV) were measured. Tumor proliferation marker Ki67 was evaluated using immunohistochemistry. The relationships between the PET/CT parameters and chemosensitivity, tumor proliferation, and overall survival (OS) were analyzed, respectively. RESULTS: The median (range) SUVmax, SUVavg, and MTV values were 11.42 (3.14-20.20), 4.8 (2.55-9.47), and 150.11 (0.19-792.46), respectively. Overall, 93.8% (45/48) of patients had high-grade serous ovarian cancer. The SUVmax value had a positive correlation with the Ki67 index (P = 0.030, r = 0.314), and a higher SUVmax level was associated with chemosensitivity (P = 0.026). However, neither SUVavg nor MTV had associations with the patients' clinicopathological parameters. None of these three PET/CT parameters were found to be potential predictors of OS. CONCLUSIONS: Preoperative 18F-FDG PET/CT had a predictive value on chemosensitivity and proliferation after primary debulking surgery in EOC patients noninvasively.

Prognostic predictive value of preoperative intratumoral 2-deoxy-2-(18F)fluoro-D-glucose uptake heterogeneity in patients with high-grade serous ovarian cancer.

OBJECTIVE: This study aimed to explore the clinical and prognostic significance of pretreatment positron-emission tomography/computed tomography (PET/CT) parameters, especially 2-deoxy-2-(F)fluoro-D-glucose-based heterogeneity, in high-grade serous ovarian cancer (HGSC). MATERIALS AND METHODS: We retrospectively investigated 56 patients with HGSC who underwent PET/CT before primary surgery at our hospital between January 2010 and June 2015. None of these patients received neoadjuvant chemotherapy. PET/CT parameters, including maximum and mean standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and intratumoral heterogeneity index (HI), were measured for all patients. Differences of each PET/CT parameter between primary tumors (-P) and omental metastatic lesions (-M) were compared by paired t tests. Progression-free survival (PFS) and overall survival were analyzed by the Kaplan-Meier method and log-rank tests in univariate analyses. Cox regression analyses were used for multivariate analysis. RESULTS: SUVmean-P was higher than SUVmean-M (P=0.001). However, there were no statistical differences of SUVmax, MTV, TLG, or HI between primary and omental lesions. Chemosensitive patients tended to have higher levels of SUVmax-P (P=0.011), MTV-P (P=0.014), TLG-P (P=0.035), and HI-P (P=0.002), respectively. In univariate analyses, higher HI-P was associated with better PFS (P=0.007). However, in multivariate analysis, HI-P was not an independent predictor of PFS (P=0.581). Neither HI-P nor HI-M was the prognostic predictor for overall survival (P=0.078 and 0.063, respectively). CONCLUSION: 2-Deoxy-2-(F)fluoro-D-glucose-based heterogeneity appears to be a predictive and prognostic factor for patients with HGSC. Parameters of primary tumors have predominant value compared with omental metastatic lesions.

Menstrual pattern after abdominal radical trachelectomy.

To assess changes of menstrual patterns, their causes, preventions and treatment methods after abdominal radical trachelectomy (ART), we recorded patients' menstrual patterns after surgery and compared them with the conditions before surgery. Patients were divided into 3 groups based on their menstrual status post-trachelectomy:Group 1: menstrual patterns unchanged; Group 2: menstrual patterns changed without amenorrhea; and Group 3: amenorrhea. One hundred and twenty-nine patients were included: 39 (30.2%) women belonged to Group 1, 74 (57.4%) to Group 2 and 16 (12.4%) to Group 3. For patients in Group 2, the most common presenting symptom was decrease of menstrual volume (59, 79.7%), followed by a prolonged (33, 44.6%) menstrual bleeding. All of the changes in Group 2 and 12 cases in Group 3 were due to narrow of the remaining cervical os. Additionally, 9 and 12 patients, respectively, in Group 2 and 3, developed cervical stenosis. To maintain regular menstruation and prevent isthmic stenosis, 99 patients had tailed intrauterine devices (IUDs) placed in the uterine cavity. Incidence of cervical stenosis all happened in patients without IUDs placed in the uterine cavity. Menstrual condition improved in all patients except one after dilation of the new-cervix. Our results demonstrated that the majority of patients suffered from changes in menstrual patterns after ART. Narrowing of the remaining cervical canal was the main reason and could be treated by cervical dilation. The use of a tailed IUD was effective in the prevention of this complication.

Origin of Magnetism in Hydrothermally Aged 2-Line Ferrihydrite Suspensions.

As an iron oxyhydroxide, nanosized ferrihydrite (Fh) is important in Earth science, biology, and industrial applications. However, its basic structure and origin of its magnetism have long been debated. We integrate synchrotron-based techniques to explore the chemical structures of 2-line ferrihydrite and to determine the origin of its magnetism during hydrothermal aging in air. Our results demonstrate that both the magnetism and X-ray magnetic circular dichroism (XMCD) signal of 2-line ferrihydrite are enhanced with aging time, and that XMCD spectral patterns resemble that of maghemite (γ-Fe2O3) rather than magnetite (Fe3O4). Fe L-edge and K-edge X-ray absorption spectroscopy (XAS) further indicate formation of both maghemite and hematite (α-Fe2O3) with increasing concentrations with longer hydrothermal aging time. Thus, magnetic enhancement with longer hydrothermal aging time is attributed to increasing maghemite concentration instead of a magnetically ordered ferrihydrite as previously reported. Moreover, L-edge and K-edge XAS spectra with different probing depths yield different ratios of these Fe oxides, which suggest the formation of a core (ferrihydrite-rich)-shell (with a mixture of both allotropes; α-Fe2O3 and γ-Fe2O3) structure during hydrothermal aging. Our results provide insights into the chemical evolution of 2-line ferrihydrite that reveal unambiguously the origin of its magnetism.

Hydrogen sulfide promotes osteogenic differentiation of human periodontal ligament cells via p38-MAPK signaling pathway under proper tension stimulation.

OBJECTIVE: Hydrogen sulfide (H2S), one of endogenous gaseous signalling molecules, can be induced by mechanical force stimulation on human periodontal ligament cells (hPDLCs). Little is known about the mechanism of H2S on the osteogenic differentiation although previous studies have demonstrated that H2S stimulated or inhibited osteoclastic differentiation. The present study was to investigate whether H2S played a regulatory role in osteogenic differentiation of the periodontal tissue remodeling and the involvement of mitogen-activated protein kinase (MAPK) signaling in this process. DESIGN: hPDLCs were applied with cycle tension force for 6h, 12h, 24h or 48h to select the optimal time for force application. Then the effects of H2S on hPDLCs osteogenic differentiation were investigated. Signal-regulated kinases p38-MAPK and ERK activities with H2S treatment were measured. Finally, specific MAPK inhibitors SB203580 and U0126 were employed to investigate the involvement of the two kinases in hPDLCs osteogenic differentiation with H2S pre-treatment. RESULTS: Tension stimulation promoted mRNA and protein expression of ALP, OCN and Runx2 in hPDLCs. The expression of ALP, OCN and Runx2 increased in a concentration-dependent manner with H2S pre-treatment. Importantly, p38-MAPK and ERK were activated in different ways upon induction by H2S. Furthermore, expression of Runx2, ALP and OCN, the osteogenic regulators, was reversed by SB203580 and U0126. CONCLUSIONS: H2S could promote osteogenic differentiation of hPDLCs by activating p38-MAPK and ERK signaling pathways.

Control of Earth-like magnetic fields on the transformation of ferrihydrite to hematite and goethite.

Hematite and goethite are the two most abundant iron oxides in natural environments. Their formation is controlled by multiple environmental factors; therefore, their relative concentration has been used widely to indicate climatic variations. In this study, we aimed to test whether hematite and goethite growth is influenced by ambient magnetic fields of Earth-like values. Ferrihydrite was aged at 95 °C in magnetic fields ranging from ~0 to ~100 µT. Our results indicate a large influence of the applied magnetic field on hematite and goethite growth from ferrihydrite. The synthesized products are a mixture of hematite and goethite for field intensities <~60 µT. Higher fields favour hematite formation by accelerating ferrimagnetic ferrihydrite aggregation. Additionally, hematite particles growing in a controlled magnetic field of ~100 µT appear to be arranged in chains, which may be reduced to magnetite keeping its original configuration, therefore, the presence of magnetic particles in chains in natural sediments cannot be used as an exclusive indicator of biogenic magnetite. Hematite vs. goethite formation in our experiments is influenced by field intensity values within the range of geomagnetic field variability. Thus, geomagnetic field intensity could be a source of variation when using iron (oxyhydr-)oxide concentrations in environmental magnetism.

The effect of visceral obesity on clinicopathological features in patients with endometrial cancer: a retrospective analysis of 200 Chinese patients.

BACKGROUND: To assess the effect of visceral adiposity on clinical and pathological characteristics in patients with endometrial cancer. METHODS: A retrospective review of medical documentation was performed in surgically treated endometrial cancer patients from January to November 2015 in our institution. The visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured at the level of umbilicus on single-slice computerized tomography. Visceral adiposity (VAT%) was calculated as VAT/(VAT + SAT). RESULTS: A total of 200 cases were included in the study. Median age at diagnosis was 54 years old. Most patients presented with early-stage tumor (86.0% for I + II) and endometrioid histology (90.5%). Positive lymph node occurred in 11.0% (22/200) of the patients with the median number of retrieved nodes as 25 (range, 4-56). The entire population had a median body mass index (BMI) of 24.7 kg/m(2) and median VAT% of 31.89%. BMI correlated with total adipose tissue (correlation coefficient = 0.667, P < 0.001), but not with VAT% (P = 0.495). Viscerally obese patients tended to be old and post-menopausal (P < 0.001; P = 0.003). Nodal metastasis and extrauterine disease were more commonly reported in patients with high VAT% (6.0% vs. 16.0%, P = 0.024; 9.0% vs. 19.0%, P = 0.042, respectively). Univariate and multivariate logistic regressions were performed to discern the contribution of variable factors on the lymph node metastasis. Grade (HR = 15.41, 95% CI = 1.60-148.76; P = 0.018), lympho-vascular invasion (HR = 449.61, 95% CI = 31.27-6463.93; P < 0.001) and high VAT% (HR = 6.37, 95% CI = 1.42-28.69; P = 0.016) retained statistical significance for predicting lymph node metastasis. CONCLUSIONS: Viscerally obese patients were more likely to be old and have positive lymph node as well as extrauterine disease. Grade, lympho-vascular invasion presence and visceral adiposity were predictors of nodal disease.

Possible gadolinium ions leaching and MR sensitivity over-estimation in mesoporous silica-coated upconversion nanocrystals.

Mesoporous silica (m-SiO2) coated gadolinium (Gd) ions-doped upconversion nanoparticles (UCNPs) are regarded as one of most attractive nano-platforms which hold great potential in future cancer theranostics. The current general synthetic strategy for such promising structures includes the extraction of surfactant molecules in the final step. Here, in this article, we focus our interest on probing the potential influence of hydrochloric acid extraction on lanthanide ions leakage, MR sensitivity over-estimation and the optical intensity weakening of m-SiO2 coated Gd-doped UCNPs. Control experiments provide evidence of inner core damage, Gd(3+) ion release and residual Gd(3+) ions "trapped" within the core@shell structures. Our investigation shows that: (1) the small Gd-doped UCNPs could be fragile and sensitive to the hydrochloric acid-extraction and thermal treatment processes; and (2) the presence of "trapped" Gd(3+) ions not only provokes the concerns of potential cytotoxicity but also interfere with the contrast imaging tests of Gd-doped UCNPs, providing possible erroneous information on the determination of the longitudinal relaxivities of given probes.

Rectal gastrointestinal stromal tumors: imaging features with clinical and pathological correlation.

AIM: To investigate computed tomography (CT) and magnetic resonance imaging (MRI) manifestations of rectal gastrointestinal stromal tumors (GISTs) in order to enhance the recognition of these rare tumors. METHODS: Fourteen patients with pathologically proven rectal GISTs were retrospectively reviewed. Patient histories were retrospectively reviewed for patient age, gender, presenting symptoms, endoscopic investigations, operation notes and pathologic slides. All tumors were evaluated for CD117, CD34 expression, and the tumors were stratified according to current criteria of the National Institutes of Health (NIH). In all cases the first pre-operation imaging findings (CT and MRI, n = 3; MRI only, n = 8; CT only, n = 3) were analyzed by two experienced radiologists by consensus, which include: tumor size, shape, CT density (hypodense, isodense and hyperdense), MRI signal intensity (hypointense, isointense and hyperintense), epicenter (intraluminal or extraluminal), margin (well-defined or ill-defined), internal component (presence of calcifications, necrosis, hemorrhage or ulceration), pattern and degree of enhancement, invasion into adjacent structures. After review of the radiologic studies, clinical and pathological findings were correlated with radiological findings. RESULTS: The patients, 13 men and 1 woman, were aged 31-62 years (mean = 51.5 ± 10.7 years). The most common initial presentation was hematochezia (n = 6). The mean tumor diameter was 5.68 ± 2.64 cm (range 1.5-11.2 cm). Eight lesions were round or oval, and 6 lesions were irregular. Eleven lesions were well-defined and 3 had ill-defined margins. Ten tumors were extraluminal and 4 were intraluminal. The density and MR signal intensity of the solid component of the lesions were similar to that of muscle on unenhanced CT (n = 6) and T1-weighted images (n = 11), and hyperintense on T2-weighted MR images. Calcification was detected in 2 tumors. Following intravenous injection of contrast media, 3 lesions had mild enhancement and 11 lesions had moderate enhancement. Enhancement was homogenous in 3 lesions and heterogeneous in 11. In 1 of 11 patients who underwent both CT and MRI, the tumor was homogenous on CT scan and heterogeneous on MRI. Eight patients were classified as high risk according to the modified recurrent risk classification system of NIH. CONCLUSION: Rectal GISTs usually manifest as large, well-circumscribed, exophytic masses with moderate and heterogeneous enhancement on CT and MRI. The invasion of adjacent organs, bowel obstruction and local adenopathy are uncommon.

A prospective study of fertility-sparing treatment with megestrol acetate following hysteroscopic curettage for well-differentiated endometrioid carcinoma and atypical hyperplasia in young women.

PURPOSE: To investigate the feasibility and efficacy of curettage with hysteroscopy followed by megestrol acetate (MA) for well-differentiated endometrioid carcinoma (EC) confined to the endometrium and for atypical hyperplasia (AH) in young women. PATIENTS AND METHODS: Fourteen patients with EC and 12 patients with AH were prospectively enrolled in this study. All of the patients received at least 12 weeks of oral MA (160 mg/day) following thorough curettage with hysteroscopy. The response was assessed histologically every 12 weeks. The primary endpoint was the complete response rate. Adverse events, pregnancy rates and recurrence rates were secondary end points. RESULTS: Twenty-one (80.8 %) patients responded to treatment. The median time to response was 12 weeks. After a median follow-up of 32 months, 6 patients had recurrences. Significantly, more patients with infertility or PCOS experienced recurrence (P = 0.040, P = 0.015). Eight patients attempted to conceive after complete response; two spontaneous conceptions and one normal delivery were achieved. No disease-related or treatment-related deaths were observed. CONCLUSIONS: Fertility-sparing treatment with MA following entirely hysteroscopic curettage is effective, demonstrating the least toxicity for rigorously selected young women with well-differentiated EC confined to the endometrium or with AH; however, close follow-up is required for the potential consequences of improper patient selection and a substantial rate of recurrence.

Localization and evaluation of sentinel lymph node in breast cancer from computed tomographic lymphography.

OBJECTIVE: This study aimed to determine the accuracy of computed tomographic (CT) localization and CT-based diagnosis of sentinel lymph nodes (SLNs) metastasis. METHODS: Thirty-four patients with confirmed breast cancer underwent 40-row CT scanning, and the first one or several lymph node(s) in the lymphatic drainage pathway was/were defined as the SLN(s). Dye and γ probe-guided SLN biopsy was performed on all patients. To accurately localize the SLN, 19 patients (55.9%) underwent the percutaneous lymph node puncture procedure. The morphologic features of all the SLNs on CT scans were analyzed and compared with the SLN biopsy pathologic diagnosis. RESULTS: Sentinel lymph nodes were successfully identified for all patients without any significant adverse effects. All localized SLNs corresponded well with SLNs identified on SLN biopsy, with an accuracy of 89.5%. Accuracy increased to 100% when the CT scan technique was combined with the blue dye method. The size criteria for metastatic diagnosis had a sensitivity of 85%, which increased to 94.7% when long-to-short-axis ratio and margin characteristics were also considered. CONCLUSIONS: The CT lymphography combined with the blue dye method accurately localized the SLNs. The CT-based diagnostic criteria improved the diagnostic accuracy of SLN metastases and were useful for evaluating the axillary status in early stage breast cancer patients.

[Diagnostic value of full-field digital mammography for breast carcinoma].

OBJECTIVE: To evaluate the diagnostic value of full-field digital mammography for breast cancer. METHODS: The clinical data and mammograms of 230 patients with breast diseases between January 2008 and July 2008 were collected and reviewed. Craniocaudal (CC) and mediolateral oblique (MLO) view mammograms were performed in all patients before surgery. Three experienced radiologists in breast imaging assessment analyzed and classified all the mammograms according to breast imaging reporting and data system (BI-RADS). The sensitivity, specificity and accuracy were evaluated according to their pathological diagnosis. The reasons resulting in false-negative and false-positive diagnosis were also analyzed. RESULTS: Of the 238 samples, 130 had a malignant breast tumors and 108 cases of benign breast lesions. One hundred and nine of the 130 malignant breast tumors were invasive ductal carcinoma. Fifty-seven of the 108 benign breast lesions were breast adenosis. Masses or masses with microcalcification were the most frequently seen signs of the malignant tumors, accounting for 40.8% and 20.8%, respectively. The sensitivity, specificity and accuracy of FFDM in detecting breast carcinoma were 90.8%, 87.0% and 89.1%, respectively. The false-negative signs including negative X-ray finding (5 cases) and focal asymmetric densities (4 cases). The false-positive signs were masses with spiculate, indistinctive or lobulated margin leading to misdiagnosing the lesions as malignant tumors. CONCLUSION: Full-field digital mammography (FFDM) is helpful in detection of breast cancers in women, with a higher sensitivity, specificity and accuracy, and has an important clinical application value.

Effect of b value on monitoring therapeutic response by diffusion-weighted imaging.

AIM: To explore the diffusion gradient b-factor that optimizes both apparent diffusion coefficient (ADC) measurement and contrast-to-noise (CNR) for assessing tumor response to transarterial chemoembolization (TACE) in a rabbit model. METHODS: Twelve New Zealand white rabbits bearing VX2 tumors in the liver were treated with TACE. Diffusion-weighted imaging (DWI) with various b values was performed using the same protocol before and 3 d after treatment with TACE. ADC values and CNR of each tumor pre- and post-treatment with different b factors were analyzed. Correlation between ADC values and extent of necrosis in histological specimens was analyzed by a Pearson's correlation test. RESULTS: The quality of diffusion-weighted images diminished as the b value increased. A substantial decrease in the mean lesion-to-liver CNR was observed on both pre- and post-treatment DW images, the largest difference in CNR pre- and post-treatment was manifested at a b value of 1000 s/mm(2) (P = 0.036 ). The effect of therapy on diffusion early after treatment was shown by a significant increase in ADCs (P = 0.007), especially with large b factors (>= 600 s/mm(2)). The mean percentage of necrotic cells present within the tumor was 76.3%-97.5%. A significant positive correlation was found between ADC values and the extent of necrosis with all b values except for b200, a higher relative coefficient between ADC values and percentage of necrosis was found on DWI with b1000 and b2000 (P = 0.002 and 0.006, respectively). CONCLUSION: An increasing b value of up to 600 s/mm(2) would increase ADC contrast pre- and post-treatment, but decrease image quality. Taking into account both CNR and ADC measurement, diffusion-weighted imaging obtained with a b value of 1000 s/mm(2) is recommended for monitoring early hepatic tumor response to TACE.

[MR imaging features of different renal cell carcinoma subtypes].

OBJECTIVE: To compare and analyze the MRI features of different renal cell carcinoma (RCC) subtypes. METHODS: The MR images of 81 surgically and pathologically confirmed renal cell carcinomas from 79 patients were reviewed retrospectively. The MR imaging features of lesions in plain scan, the degree and patterns of lesion enhancement (homogeneous, heterogeneous, peripheral), and tumor spreading patterns were analyzed. In order to evaluate the diagnostic validity of differentiating RCC subtypes using signal enhancement, receiver operating characteristic curves (ROC) were generated. The cutoff value of post-contrast signal intensity to noise ratios (SNR) of the tumor parenchyma were also generated in order to differentiate clear cell RCC from other subtypes. RESULTS: Of the 81 lesions, 58 were clear cell carcinomas, 10 chromophobe cell carcinomas, 8 papillary cell carcinomas, and 5 unclassified RCC. All the chromophobe cell subtype tumors showed a homogeneous density (P < 0.05). The clear cell subtype tumors were likely heterogenous, and also showed heterogenous enhancement with mixed signal than other subtypes (P < 0.05). The cutoff value of SNR, which was used to differentiate clear cell subtype from the other subtypes, were 616 (corticomedullary phase), 579 (nephrographic phase) and 278 (excretory phase), retrospectively. The nephrographic phase is the most appropriate for differentiation, with a sensitivity of 62.1%, specificity of 91.3%, positive predictive value of 94.7%, negative predictive value of 48.8% and an accuracy value of 70.3%. No significant difference was found in tumor spreading patterns among all subtypes of RCC. CONCLUSION: MR imaging features, particularly tumor heterogeneity and degree of enhancement are useful in differentiation of the renal cell carcinoma subtypes, and in choosing an individualized therapy.