MRI for Hepatitis B-Associated Intrahepatic Cholangiocarcinoma: A Multicenter Comparative Study.

BACKGROUND: The diagnosis of intrahepatic cholangiocarcinoma (iCCA) is challenging in hepatitis B virus (HBV)-infected patients, due to the overlapping clinical manifestations and atypical imaging patterns compared to patients without HBV. PURPOSE: To investigate the preoperative imaging characteristics of iCCA in patients with HBV in comparison to those without HBV. STUDY TYPE: Retrospective. SUBJECTS: 431 patients with histopathologically confirmed iCCA (143 HBV-positive and 288 HBV-negative patients) were retrospectively enrolled from three institutes, and patients were allocated to the training (n = 302) and validation (n = 129) cohorts from different institutes or time period; 100 matching HBV-positive hepatocellular carcinoma (HCC) patients were also enrolled. FIELD STRENGTH/SEQUENCE: 1.5-T and 3-T, including T1- and T2-weighted, diffusion-weighted and dynamic gadopentetate dimeglumine-enhanced imaging. ASSESSMENT: Clinical and MRI features were analyzed and compared between HBV-positive and HBV-negative patients with iCCA, and between HBV-positive patients with iCCA and HCC. STATISTICAL TESTS: Univariate and multivariate logistic regression analyses with odds ratio (OR) to identify independent features for discriminating HBV-associated iCCA. Diagnostic model generation by incorporating independent features, and the performance for discrimination was evaluated by receiver operating characteristics with the area under the curve (AUC) and 95% confidence interval (CI). AUCs were compared by the DeLong's method. A P-value <0.05 was considered statistically significant. RESULTS: Compared to patients without HBV, washout or degressive enhancement pattern (OR = 51.837), well-defined tumor margin (OR = 8.758) and no peritumoral bile duct dilation (OR = 4.651) were independent significant features for discriminating HBV-associated iCCAs. All these features were also the predominant MRI manifestations for HBV-associated HCC. The combined index showed an AUC of 0.798 (95% CI 0.748-0.842) in the training cohort and an AUC of 0.789 (95% CI 0.708-0.856) in the validation cohort for discrimination. The sensitivity, specificity, and accuracy were all >70%, which was superior to each single feature alone in both cohorts. [Correction added after first online publication on 29 June 2023. The Field Strength/Sequence has been updated from 5-T to 1.5-T.] DATA CONCLUSION: Preoperative MRI may help to discriminate HBV-associated iCCA. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY STAGE: 2.

A multi-center diagnostic system for intrahepatic mass-forming cholangiocarcinoma based on preoperative MRI and clinical features.

OBJECTIVES: To establish a non-invasive diagnostic system for intrahepatic mass-forming cholangiocarcinoma (IMCC) via decision tree analysis. METHODS: Totally 1008 patients with 504 pathologically confirmed IMCCs and proportional hepatocellular carcinomas (HCC) and combined hepatocellular cholangiocarcinomas (cHCC-CC) from multi-centers were retrospectively included (internal cohort n = 700, external cohort n = 308). Univariate and multivariate logistic regression analyses were applied to evaluate the independent clinical and MRI predictors for IMCC, and the selected features were used to develop a decision tree-based diagnostic system. Diagnostic efficacy of the established system was calculated by the receiver operating characteristic curve analysis in the internal training-testing and external validation cohorts, and also in small lesions ≤ 3 cm. RESULTS: Multivariate analysis revealed that female, no chronic liver disease or cirrhosis, elevated carbohydrate antigen 19-9 (CA19-9) level, normal alpha-fetoprotein (AFP) level, lobulated tumor shape, progressive or persistent enhancement pattern, no enhancing tumor capsule, targetoid appearance, and liver surface retraction were independent characteristics favoring the diagnosis of IMCC over HCC or cHCC-CC (odds ratio = 3.273-25.00, p < 0.001 to p = 0.021). Among which enhancement pattern had the highest weight of 0.816. The diagnostic system incorporating significant characteristics above showed excellent performance in the internal training (area under the curve (AUC) 0.971), internal testing (AUC 0.956), and external validation (AUC 0.945) cohorts, as well as in small lesions ≤ 3 cm (AUC 0.956). CONCLUSIONS: In consideration of the great generalizability and clinical efficacy in multi-centers, the proposed diagnostic system may serve as a non-invasive, reliable, and easy-to-operate tool in IMCC diagnosis, providing an efficient approach to discriminate IMCC from other HCC-containing primary liver cancers. CLINICAL RELEVANCE STATEMENT: This study established a non-invasive, easy-to-operate, and explainable decision tree-based diagnostic system for intrahepatic mass-forming cholangiocarcinoma, which may provide essential information for clinical decision-making. KEY POINTS: • Distinguishing intrahepatic mass-forming cholangiocarcinoma (IMCC) from other primary liver cancers is important for both treatment planning and outcome prediction. • The MRI-based diagnostic system showed great performance with satisfying generalization ability in the diagnosis and discrimination of IMCC. • The diagnostic system may serve as a non-invasive, easy-to-operate, and explainable tool in the diagnosis and risk stratification for IMCC.

Liver fat volume fraction measurements based on multi-material decomposition algorithm in patients with nonalcoholic fatty liver disease: the influences of blood vessel, location, and iodine contrast.

BACKGROUND: In recent years, spectral CT-derived liver fat quantification method named multi-material decomposition (MMD) is playing an increasingly important role as an imaging biomarker of hepatic steatosis. However, there are various measurement ways with various results among different researches, and the impact of measurement methods on the research results is unknown. The aim of this study is to evaluate the reproducibility of liver fat volume fraction (FVF) using MMD algorithm in nonalcoholic fatty liver disease (NAFLD) patients when taking blood vessel, location, and iodine contrast into account during measurement. METHODS: This retrospective study was approved by the institutional ethics committee, and the requirement for informed consent was waived because of the retrospective nature of the study. 101 patients with NAFLD were enrolled in this study. Participants underwent non-contrast phase (NCP) and two-phase enhanced CT scanning (late arterial phase (LAP) and portal vein phase (PVP)) with spectral mode. Regions of interest (ROIs) were placed at right posterior lobe (RPL), right anterior lobe (RAL) and left lateral lobe (LLL) to obtain FVF values on liver fat images without and with the reference of enhanced CT images. The differences of FVF values measured under different conditions (ROI locations, with/without enhancement reference, NCP and enhanced phases) were compared. Friedman test was used to compare FVF values among three phases for each lobe, while the consistency of FVF values was assessed between each two phases using Bland-Altman analysis. RESULTS: Significant difference was found between FVF values obtained without and with the reference of enhanced CT images. There was no significant difference about FVF values obtained from NCP images under the reference of enhanced CT images between any two lobes or among three lobes. The FVF value increased after the contrast injection, and there were significant differences in the FVF values among three scanning phases. Poor consistencies of FVF values between each two phases were found in each lobe by Bland-Altman analysis. CONCLUSION: MMD algorithm quantifying hepatic fat was reproducible among different lobes, while was influenced by blood vessel and iodine contrast.

Association between physical frailty, circadian syndrome and cardiovascular disease among middle-aged and older adults: a longitudinal study.

BACKGROUND: Physical frailty (PF) and circadian syndrome (CircS) are proposed as novel risks for cardiovascular disease (CVD), but little attention is paid to their combined impact on CVD. This study aimed to investigate the association of PF, CircS and CVD in middle-aged and older adults. METHODS: The sample comprised 8512 participants aged at least 45 years from the China Health and Retirement Longitudinal Study (CHARLS) 2011. PF was examined by the physical frailty phenotype scale. CircS was assessed by the components of the International Diabetes Federation (IDF) MetS plus short sleep duration and depression. The cut-off for CircS was set as ≥ 4. CVD was defined as the presence of physician-diagnosed heart disease and/or stroke. A total of 6176 participants without CVD recruited from CHARLS 2011 and were followed up in 2018. RESULTS: The prevalence of CVD in total populations, neither CircS or PF, PF alone, CircS alone and both CircS and PF were 13.0%, 7.4%, 15.5%, 17.4%, and 30.2%, respectively. CircS was more likely to be PF [OR (95%CI): 2.070 (1.732 ∼ 2.472)] than those without CircS. Both CircS alone [OR (95% CI): 1.954 (1.663 ∼ 2.296)], and coexisting CircS and PF [3.508 (2.739 ∼ 4.494)] were associated with CVD. Longitudinal analysis showed that individuals with both CircS and PF (HR: 1.716, 95%CI: 1.314 ∼ 2.240) and CircS alone [1.520 (1.331 ∼ 1.737)] were more likely to have new onset CVD than neither CircS or PF peers. CONCLUSION: PF and CircS together are associated with higher CVD risk, which provided new evidence for a strong relation that warrants attention to assessing PF and CircS and in community to promote healthy aging.

The significance of the predominant component in combined hepatocellular-cholangiocarcinoma: MRI manifestation and prognostic value.

PURPOSE: To investigate the significance of the predominant component of combined hepatocellular-cholangiocarcinoma (cHCC-CC) in terms of MRI manifestation and its potential prognostic value compared to hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). MATERIALS AND METHODS: A total of 300 patients with chronic liver disease from two centers were retrospectively enrolled, including 100 surgically proven cases of cHCC-CC, HCC, and ICC each. Univariate and multivariate regression analyses were performed to identify independent predictors for distinguishing HCC-predominant cHCC-CC and ICC-predominant cHCC-CC from HCC and ICC, respectively. Diagnostic models were constructed based on the independent features. Recurrence-free survival (RFS) was estimated and compared between groups. RESULTS: The predominant component was an independent predictor for RFS in cHCC-CC (hazard ratio = 1.957, P = 0.044). The presence of targetoid appearance (odds ratio(OR) = 10.907, P = 0.001), lack of enhancing capsule (OR = 0.072, P = 0.001) and arterial peritumoral enhancement (OR = 0.091, P = 0.003) were independent predictors suggestive of HCC-predominant cHCC-CC over HCC; their combination yielded an area under the curve of 0.756. No significant differences were observed in RFS between HCC-predominant cHCC-CC and HCC (P = 0.864). Male gender (OR = 4.049, P = 0.015), higher alpha fetoprotein (OR = 16.789, P < 0.001) and normal carbohydrate antigen 19-9 (OR = 0.343, P = 0.036) levels, presence of enhancing capsule (OR = 7.819, P < 0.001) and hemorrhage (OR = 23.526, P = 0.004), and lack of targetoid appearance (OR = 0.129, P = 0.005) and liver surface retraction (OR = 0.190, P = 0.021) were independent predictors suggestive of ICC-predominant cHCC-CC over ICC; their combination yielded an area under the curve value of 0.898. ICC-predominant cHCC-CC exhibited poorer survival with shorter RFS than ICC (P = 0.009). CONCLUSION: The predominant histopathological component is closely related to the imaging manifestation of cHCC-CC; and more importantly, it plays a significant prognostic role, which may alter the RFS prognosis of cHCC-CC.

Detecting single infrared photons toward optimal system detection efficiency.

Superconducting nanowire single-photon detector (SNSPD) with near-unity system efficiency is a key enabling, but still elusive, technology for numerous quantum fundamental theory verifications and quantum information applications. The key challenge is to have both a near-unity photon-response probability and absorption efficiency simultaneously for the meandered nanowire with a finite filling ratio, which is more crucial for NbN than other superconducting materials (e.g., WSi) with lower transition temperatures. Here, we overcome the above challenge and produce NbN SNSPDs with a record system efficiency by replacing a single-layer nanowire with twin-layer nanowires on a dielectric mirror. The detector at 0.8 K shows a maximal system detection efficiency (SDE) of 98% at 1590 nm and a system efficiency of over 95% in the wavelength range of 1530-1630 nm. Moreover, the detector at 2.1 K demonstrates a maximal SDE of 95% at 1550 nm using a compacted two-stage cryocooler. This type of detector also shows the robustness against various parameters, such as the geometrical size of the nanowire and the spectral bandwidth, enabling a high yield of 73% (36%) with an SDE of >80% (90%) at 2.1 K for 45 detectors fabricated in the same run. These SNSPDs made of twin-layer nanowires are of important practical significance for batch production.

Multispectral superconducting nanowire single photon detector.

In this work, we report multispectral superconducting nanowire single photon detectors (SNSPDs) that can simultaneously detect single photons at multiple wavelengths with high efficiency. The superconducting nanowires are fabricated on an all-dielectric mirror consisting of two quarter-wave stack reflectors with separated central wavelengths. The unique optical structure results in serially coupled optical cavities, leading to multiple resonant absorption bands that are utilized for high-efficiency single photon detection. The fabricated detector shows system detection efficiencies of >80% at the three target wavelengths of 1550 nm, 1310 nm, and 1064 nm. The multispectral detector may eliminate the need for multiple SNSPDs for different wavelengths in a system, potentially resulting in a reduction in size, weight, and power, as well as in the cost of the overall detection system. The detector may also find interesting use for applications such as multispectral ranging or imaging.

Ultra-broadband microfiber-coupled superconducting single-photon detector.

Broadband photon detectors are a key enabling technology for various applications such as spectrometers, light detection and ranging. In this work, we report on an ultra-broadband single-photon detector based on a microfiber (MF)-coupled superconducting nanowires structure operating in the spectral range from visible to near-infrared light. The MF-coupled superconducting nanowire single-photon detector (SNSPD) is formed by placing an MF on top of superconducting niobium nitride (NbN) nanowires, allowing ultra-broadband photon detection due to their nearly lossless transmission/absorption and nearly unity internal efficiency for ultra-broad waveband. The simulation results indicate that with optimal device structure, the optical absorption with efficiency > 90% can be realized over a wavelength range of 350 nm to 2150 nm. The fabricated MF-coupled SNSPD shows unparalleled broadband system detection efficiencies (SDEs) of more than 50% from 630 nm to 1500 nm. The SDEs reach 66% at 785 nm and 45% at 1550 nm. These results pave the way for ultra-broadband weak light detection with quantum-limit sensitivity.

Fast and high efficiency superconducting nanowire single-photon detector at 630 nm wavelength.

Fast and high efficiency single-photon detectors have important applications in the fields of life science and quantum information. We report, herein, a serially connected two superconducting nanowire avalanche photon detector (SC2-SNAP) fabricated on a dielectric mirror aiming to 630 nm wavelength. This detector shows system detection efficiency (SDE) of 84.8% at a dark count rate of 10 Hz and offers fast detection speed while maintaining a high SDE, where the counting rate reaches 53.9 MHz at an SDE of 60%. This fast and high efficiency single-photon detector may find applications in fluorescence correlation spectroscopy and quantum key distribution.

Large-area multispectral superconducting nanowire single-photon detector.

In this work, we report a large-active-area multispectral superconducting nanowire single-photon detector for free-space applications. The detector is realized by fabricating NbTiN nanowire with an active area of 35 µm diameter on two serially connected dielectric mirrors that can simultaneously and efficiently detect single photons at the three typical wavelengths employed in free-space applications, namely, 532, 850, and 1064 nm. Maximal system detection efficiencies (SDEs) of 80.0% at 532 nm and 850 nm and 75.8% at 1064 nm are achieved for polarized light obtained by coupling the detector with an SMF-28 fiber. Upon coupling with a 50 µm multimode fiber, SDEs of 68.6%, 59.6%, and 47.0%, are achieved for 532, 850, and 1064 nm wavelength unpolarized light, respectively. Moreover, the detector shows timing jitters of 37.1 and 41.0 ps when coupled with SMF-28 fiber and 50 µm multimode fiber. This type of detector with a large active area and multiwavelength detection capability is promising for both single and multiwavelength free-space applications.

Minimally Invasive CABG or Hybrid Coronary Revascularization for Multivessel Coronary Diseases: Which Is Best? A Systematic Review and Metaanalysis.

OBJECTIVES: Minimally invasive coronary revascularization (MICR) involves minimally invasive direct coronary artery bypass grafting (MIDCAB) and robotic-assisted coronary artery bypass grafting (RCABG), and hybrid coronary revascularization (HCR) aims to combine MICR/RCABG on left anterior descending (LAD) and percutaneous coronary interventions (PCI) on non-LAD lesions. We performed a systematic review and metaanalysis to compare clinical outcome after MICR and HCR. METHODS: A metaanalysis was carried out through searching PubMed, EMBASE, Web of Science, and Medline for comparative studies evaluating the primary and secondary clinical end points. RESULTS: A systematic literature search identified 8 observational studies that satisfied our inclusion criteria, including being suitable for metaanalysis; the studies were between 1990 and 2018 and included 1084 cases of HCR and 2349 cases of MICR. Metaanalysis of these studies showed that HCR was associated with a reduced need for ICU LOS (WMD -11.46 hours, 95% CI, -18.76 ~ -4.25, P = .02), to hospital time (WMD -1.34 hours, 95% CI, -2.42 to 0.26, P < .01), and blood transfusion (OR 0.43, 95% CI, 0.31-0.59, P < .00001) than MICR. Comparisons of individual components showed no significant difference in terms of in-hospital mortality, MACCE, shock, myocardial infarction (MI), long-term survival, total variable cost, and surgical complications (including renal failure, chest drainage, bleeding). CONCLUSIONS: HCR was noninferior to MICR in terms of in-hospital mortality, MACCE, shock, MI, long-term survival, total variable cost, and surgical complications (including renal failure, chest drainage, bleeding), whereas HCR was associated with a reduced need for ICU LOS, hospital time, and blood transfusion than MICR and less infection than MICR. Further randomized studies are warranted to corroborate these observational data.

Histogram analyses of diffusion kurtosis indices and apparent diffusion coefficient in assessing liver regeneration after ALPPS and a comparative study with portal vein ligation.

PURPOSE: To investigate the value of diffusion kurtosis imaging (DKI) histogram analysis in assessing liver regeneration and the microstructure basis after associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), in comparison with portal vein ligation (PVL). MATERIALS AND METHODS: Thirty rats were divided into the ALPPS, PVL, and control groups. Histograms of DKI using a 3T magnetic resonance imaging (MRI) scanner were performed for corrected apparent diffusion (D), kurtosis (K), and apparent diffusion coefficient (ADC). Mean, median, skewness, kurtosis, and the percentiles (5th , 25th , 50th , 75th , and 95th ) were generated and compared, and radiologic-pathologic correlations were evaluated. RESULTS: There were more significant volume increases of the right median lobe after ALPPS than PVL (P = 0.0304/0.0017). The ALPPS group had larger hepatocyte size (P = 0.009/0.000), higher Ki-67 and hepatocyte growth factor expression (P = 0.001-0.036) compared with both PVL and control groups. Mean, median, 5th , 25th , 50th , 75th percentiles of D map in ALPPS were lower than the control group (P = 0.001-0.022). Skewness and 75th , 95th percentiles of K map in ALPPS were higher than the PVL group (P = 0.011-0.042). No differences existed in the ADC map between groups (P = 0.073-0.291). Mean, median, 5th , 25th , 50th percentiles of D map, and 5th percentile of K map showed significant correlations with hepatocyte size (r = -0.582 to -0.426); no significant correlations were found in ADC parameters (P = 0.460-0.934). CONCLUSION: ALPPS induced true accelerated liver hypertrophy, superior to that seen with PVL. Histogram analysis of diffusion kurtosis indices may provide added values in evaluating liver regeneration and the intrinsic microstructure basis after ALPPS in comparison with the standard monoexponential ADC. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: Stage 2 J. Magn. Reson. Imaging 2018;47:729-736.

Assessment of liver regeneration after associating liver partition and portal vein ligation for staged hepatectomy: a comparative study with portal vein ligation.

BACKGROUND: To investigate the diagnostic value of diffusion kurtosis imaging (DKI) and diffusion-weighted imaging (DWI) in assessing liver regeneration after associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) compared with portal vein ligation (PVL). METHODS: Thirty rats were divided into the ALPPS, PVL, and control groups. DKI and DWI were performed before and 7 days after surgery. Corrected apparent diffusion (D), kurtosis (K) and apparent diffusion coefficient (ADC) were calculated and compared, radiologic-pathologic correlations were evaluated. RESULTS: The volume of the right median lobe increased significantly after ALPPS. There were larger cellular diameters after ALPPS and PVL (P = 0.0003). The proliferative indexes of Ki-67 and hepatocyte growth factor were higher after ALPPS (P = 0.0024/0.0433). D, K and ADC values differed between the groups (P = 0.021/0.0015/0.0008). A significant correlation existed between D and the hepatocyte size (r = -0.523), no correlations existed in ADC and K (P = 0.159/0.111). The proliferative indexes showed moderate negative correlations with ADC (r = -0.484/-0.537) and no correlations with D and K (P = 0.100-0.877). DISCUSSION: Liver regeneration after ALPPS was effective and superior to PVL. DKI, especially the D map, may provide added value in evaluating the microstructure of liver regeneration after ALPPS, but this model alone may perform no better than the standard monoexponential model of DWI.

Use of enhanced T2 star-weighted angiography (ESWAN) and R2* values to distinguish ovarian cysts due to endometriosis from other causes.

PURPOSE: To evaluate the feasibility of enhanced T2 star-weighted angiography (ESWAN) in differentiating endometrial from non-endometrial cysts. METHODS: Forty-nine patients with 60 histopathologically proven ovarian cystic lesions underwent pelvic MRI including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), liver acquisition with volume acceleration, and ESWAN. Ovarian cystic lesions were divided into endometrial cysts (group 1; n = 28), pyosalpinx and hydrosalpinx (group 2; n = 13), and ovarian cystic and cystic-solid tumors (group 3; n = 19). R2* (effective transverse relaxation rate) values were measured and pairwise comparison of the R2* values among the three groups was made using Kruskal-Wallis test. Receiver operating characteristic curves were used to calculate cutoff values and performance of R2* values for distinguishing among groups. T1WI signal intensity and R2* value were also compared using area under curve values. RESULTS: R2* values for group 1 were statistically higher than groups 2 and 3 (15.37, 1.40, and 1.79 Hz, respectively; P < 0.001). The cutoff value for R2* was 7.43 Hz with a sensitivity, specificity, PPV, NPV, and accuracy of 96.43, 87.50, 87.10, 96.55, and 91.67%, respectively. There was no significant difference between the R2* value and T1WI in diagnosing endometrial cysts. CONCLUSIONS: The R2* value provides an effective way to discriminate endometrial cysts from other ovarian cystic lesions.

Use of diffusion tensor imaging in assessing superficial myometrial invasion by endometrial carcinoma: a preliminary study.

BACKGROUND: Magnetic resonance imaging (MRI) remains the standard modality for local staging of gynecological malignancies, but it has several limitations, especially when differentiating a cancer limited to the endometrium from a cancer invading the superficial myometrium. PURPOSE: To explore 1.5 T diffusion tensor imaging (DTI) in assessing superficial myometrial infiltration by endometrial carcinoma. MATERIAL AND METHODS: We analyzed the sensitivity of apparent diffusion coefficient (ADC) versus fractional anisotropy (FA) in diagnosing superficial myometrial infiltration compared to DCE-MRI and T2-weighted imaging (T2WI) in 35 patients with endometrial cancer. For each patient, T2WI-DWI fusion images were generated, and five regions of interest (ROIs) were placed on corresponding DTI images. ADC and FA were calculated, and fiber tractography (FT) images for each level were obtained. ADC and FA values for the five ROIs were compared. RESULTS: In distinguishing cancerous versus non-cancerous areas within superficial myometrium, median ADC values were significantly lower (1.16 vs. 1.48, respectively; P < 0.001) and median FA values were significantly higher (0.41 vs. 0.27; P < 0.001, respectively). ADC's versus FA's sensitivity, specificity, PPV, NPV, and accuracy for diagnosing superficial myometrial invasion were 74.3%, 88.6%, 86.7%, 77.5%, 81.4% versus 88.6%, 97.1%, 96.9%, 89.5%, 92.9%, respectively. T2WI and DCE-MR showed a sensitivity of 80.0% and 77.1%, respectively, in diagnosing myometrial invasion. CONCLUSION: Both ADC and FA were able to distinguish between cancerous verss non-cancerous areas within superficial myometrium (although FA was more sensitive based on AUC values). In addition, FA was superior to ADC, and more sensitive than T2WI and DCE-MR, in evaluating myometrial invasion. FT images provided visual confirmation of irregular arrangement and direction of the fibers due to proliferation of stromal cells caused by superficial myometrial invasion.

[Preliminary study of improved quality of computed tomographic angiography on tumor blood supply arteries of gastrointestinal tract malignant tumors with low tube voltage and low concentration contrast medium].

OBJECTIVE: To assess the image quality of gastrointestinal tract malignant tumors arteries using low tube voltage, low contrast medium concentration and 50% adaptive statistical iterative reconstruction (ASiR) algorithm. METHODS: A total of 58 patients with pathologically confirmed gastrointestinal tract malignant tumors and body mass index (BMI) under 22 kg/m² undergoing computed tomography (CT) scanning during March-December 2013. They were randomly divided into group A (270 mgI/ml of contrast medium, 80 kVp tube voltage scanning and 50% ASiR; 21 males and 11 females with an age range of 40-90 years) and group B (350 mgI/ml of contrast medium, 120 kVp routine tube voltage; 22 males and 4 females with an age range of 40-76 years). The inter-group differences of age and gender ratio were compared with Mann-Whitney U and Fisher exact tests respectively. Two independent radiologists reviewed reconstructions and separated the reconstructed image into 5 points according to image quality. The CT value of tumor blood supplying artery (CT1 value) and fat in anterior abdominal wall (SD value) were measured and image noise, contrast-to-noise ratio (CNR) and figure of merit (FOM) calculated. The interobserver variation was estimated by weighted kappa statistics and intra-class correlation coefficients (ICC) test. The point of image quality of two groups was compared by Mann-Whitney U test. The paired Student t test was used to compare the inter-group differences in CT1, SD, CNR, FOM and CT dose index (CTDIvol). RESULTS: No inter-group difference existed in patient age or gender ratio. The consistency of two radiologists was excellent (kappa value > 0.80; ICC value > 0.75). The subjective image quality scores of tumor blood supplying arteries showed no inter-group difference (P = 0.09). The tumor blood supply arteries CT value, CNR and FOM of group A (459 ± 69 HU, 20.2 ± 3.3 and 85 ± 37) were significantly higher than those of group B (250 ± 42 HU, 9.3 ± 1.9 and 9 ± 4) (both P < 0.01). The SD value of group A (20.0 ± 1.7) was obviously lower than that of group B (22.4 ± 3.2) (P < 0.01). And the CTDIvol of group A (5.2 ± 1.2 mGy) was obviously lower than that of group B (13.5 ± 4.7 mGy) (P < 0.01). CONCLUSION: For patients of BMI ≤ 22 kg/m², low tube voltage and low contrast medium concentration scan condition with 50% ASiR algorithm is feasible for acquiring better quality image and ensuring significant reduction in effective dose.

[Optimal monochromatic images of abdominal arteries with low concentrations of contrast agents in spectral computed tomography imaging].

OBJECTIVE: To explore the application of optimal monochromatic images according to computed tomography (CT) values of conventional CT scans with high concentration contrast agent and the feasibility in guiding abdominal arteries imaging with low concentration contrast. METHODS: From March 2013 to February 2014, 160 patients of suspected celiac disease with a body mass index (BMI) of >25 kg/m(2) underwent spectral CT scan. And they were randomly divided into two groups. In group A (n = 61), 270 mgI/ml low concentrations of contrast agents and spectral CT imaging; in group B (n = 99), 350 mgI/ml high concentrations of contrast agents and 120 kVp scan. For CT values of the first measurement of abdominal aorta B group of patients, the average CT value was calculated . The optimal monochromatic images of group A according to CT values of group B were reconstructed and 70 keV images (group C) also reconstructed. The CT values of hepatic, splenic, right renal and superior mesenteric arteries were measured and contrast to noise ratios (CNRs) calculated. CT values and CNR were compared through t test on independent samples. P > 0.05 indicated no significant difference. RESULTS: Mean CT value of abdominal aorta was (422 ± 65) HU in group B. And optimal keV was (67 ± 5) keV in group A. CT values of abdominal aorta and its branches showed no statistical significance; the CNRs of abdominal aorta and its branches showed statistical significance. The scoring consistency between two observers was excellent and the score (4.1 ± 0.9 vs 4.2 ± 0.7) showed no significant difference (P > 0.05). CONCLUSION: GSI abdominal scans with low concentration contrast may obtain better image qualities compared to conventional CTA of high concentration. And (67 ± 5) keV is recommended.

Hybrid aortic arch procedure in acute type A aortic dissection with right carotid artery occlusion.

Acute type A aortic dissection complicated by carotid artery is associated with a high risk of perioperative stroke. We reported a case of application of hybrid aortic arch debranching procedure in acute type A aortic dissection complicated by right carotid artery occlusion, which resulted in no neurological complications after operation and patent carotid artery after discharging.

2D-3D cascade network for glioma segmentation in multisequence MRI images using multiscale information.

BACKGROUND AND OBJECTIVE: Glioma segmentation is an important procedure for the treatment plan and follow-up evaluation of patients with glioma. UNet-based networks are widely used in medical image segmentation tasks and have achieved state-of-the-art performance. However, context information along the third dimension is ignored in 2D convolutions, whereas difference between z-axis and in-plane resolutions is large in 3D convolutions. Moreover, an original UNet structure cannot capture fine details because of the reduced resolution of feature maps near bottleneck layers. METHODS: To address these issues, a novel 2D-3D cascade network with multiscale information module is proposed for the multiclass segmentation of gliomas in multisequence MRI images. First, a 2D network is applied to fully exploit potential intra-slice features. A variational autoencoder module is incorporated into 2D DenseUNet to regularize a shared encoder, extract useful information, and represent glioma heterogeneity. Second, we integrated 3D DenseUNet with the 2D network in cascade mode to extract useful inter-slice features and alleviate the influence of large difference between z-axis and in-plane resolutions. Moreover, a multiscale information module is used in the 2D and 3D networks to further capture the fine details of gliomas. Finally, the whole 2D-3D cascade network is trained in an end-to-end manner, where the intra-slice and inter-slice features are fused and optimized jointly to take full advantage of 3D image information. RESULTS: Our method is evaluated on publicly available and clinical datasets and achieves competitive performance in these two datasets. CONCLUSIONS: These results indicate that the proposed method may be a useful tool for glioma segmentation.

Cell sheet formation enhances the therapeutic effects of human umbilical cord mesenchymal stem cells on myocardial infarction as a bioactive material.

Stem cell-based therapy has been used to treat ischaemic heart diseases for two decades. However, optimal cell types and transplantation methods remain unclear. This study evaluated the therapeutic effects of human umbilical cord mesenchymal stem cell (hUCMSC) sheet on myocardial infarction (MI). METHODS: hUCMSCs expressing luciferase were generated by lentiviral transduction for in vivo bio-luminescent imaging tracking of cells. We applied a temperature-responsive cell culture surface-based method to form the hUCMSC sheet. Cell retention was evaluated using an in vivo bio-luminescent imaging tracking system. Unbiased transcriptional profiling of infarcted hearts and further immunohistochemical assessment of monocyte and macrophage subtypes were used to determine the mechanisms underlying the therapeutic effects of the hUCMSC sheet. Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function, angiogenesis and left ventricular remodelling. RESULTS: When transplanted to the infarcted mouse hearts, hUCMSC sheet significantly improved the retention and survival compared with cell suspension. At the early stage of MI, hUCMSC sheet modulated inflammation by decreasing Mcp1-positive monocytes and CD68-positive macrophages and increasing Cx3cr1-positive non-classical macrophages, preserving the cardiomyocytes from acute injury. Moreover, the extracellular matrix produced by hUCMSC sheet then served as bioactive scaffold for the host cells to graft and generate new epicardial tissue, providing mechanical support and routes for revascularsation. These effects of hUCMSC sheet treatment significantly improved the cardiac function at days 7 and 28 post-MI. CONCLUSIONS: hUCMSC sheet formation dramatically improved the biological functions of hUCMSCs, mitigating adverse post-MI remodelling by modulating the inflammatory response and providing bioactive scaffold upon transplantation into the heart. TRANSLATIONAL PERSPECTIVE: Due to its excellent availability as well as superior local cellular retention and survival, allogenic transplantation of hUCMSC sheets can more effectively acquire the biological functions of hUCMSCs, such as modulating inflammation and enhancing angiogenesis. Moreover, the hUCMSC sheet method allows the transfer of an intact extracellular matrix without introducing exogenous or synthetic biomaterial, further improving its clinical applicability.