Differentiation between dysplastic nodule and early-stage hepatocellular carcinoma: The utility of conventional MR imaging

AIM:To elucidate the variety of ways early-stage hepatocellular carcinoma(HCC)can appear on magnetic resonance(MR)imaging by analyzing T1-weighted,T2-weighted,and gadolinium-enhanced dynamic studies.METHODS:Seventy-three patients with well-differentiated HCC(wHCC)or dysplastic nodules were retrospectively identified from medical records,and new histological sections were prepared and reviewed.The tumor nodules were categorized into three groups:dysplastic nodule(DN),wHCC compatible with Edmondson-Steiner grade I HCC(w1-HCC),and wHCC compatible with Edmondson-Steiner gradeⅡHCC(w2-HCC).The signal intensity on pre-contrast MR imaging and the enhancing pattern for each tumor were recorded and compared between the three tumor groups.RESULTS:Among the 73 patients,14 were diagnosed as having DN,40 were diagnosed as having w1-HCC,and 19 were diagnosed as having w2-HCC.Hyperintensity measurements on T2-weighted axial images(T2WI)were statistically significant between DNs and wHCC(P=0.006)and between DN and w1-HCC(P=0.02).The other imaging features revealed no significant differences between DN and wHCC or between DN and w1-HCC.Hyperintensity on both T1W out-phase imaging(P=0.007)and arterial enhancement on dynamic study(P=0.005)showed statistically significant differences between w1-HCC and w2-HCC.The other imaging features revealed no significant differences between w1-HCC and w2-HCC.CONCLUSION:In the follow-up for a cirrhotic nodule,increased signal intensity on T2WI may be a sign of malignant transformation.Furthermore,a noted loss of hyperintensity on T1WI and the detection of arterial enhancement might indicate further progression of the histological grade.

Refinement of Enhanced Speech Using Hybrid-Median Filter and Harmonic Regeneration Approach

This study proposes a post-processor to improve the harmonic structure of a vowel in an enhanced speech, enabling the speech quality to be improved. Initially, a speech enhancement algorithm is employed to reduce the background noise for a noisy speech. Hence the enhanced speech is post-processed by a hybrid-median filter to reduce the musical effect of residual noise. Since the harmonic spectra are impacted by background noise and a speech enhancement process, the quality of a vowel is deteriorated. A harmonic regenerated method is developed to improve the quality of post-processed speech. Experimental results show that the proposed method can improve the quality of post-processed speech by adequately regenerating harmonic spectra.

Association between MDM2-SNP309 and hepatocellular carcinoma in Taiwan Residents population

AIM:To investigate the risk association and compare the onset age of hepatocellular carcinoma(HCC) patients in Taiwan with different genotypes of MDM2- SNP309. METHODS:We analyzed MDM2-SNP309 genotypes from 58 patients with HCC and 138 cancer-free healthy controls consecutively.Genotyping of MDM2-SNP309 was conducted by restriction fragment length polymor- phism assay. RESULTS:The proportion of homozygous MDM2- SNP309 genotype(G/G)in cases and cancer-free healthy controls was similar(17.2%vs 16.7%).Multi-variate analysis showed that the risk of G/G genotypeof MDM2-SNP309 vs wild-type T/T genotype in patients with HCC was not significant(OR=1.265,95% CI=0.074-21.77)after adjustment for sex,hepatitis B or C virus infection,age,and cardiovascular disease/ diabetes.Nevertheless,there was a trend that GG genotype of MDM2-SNP309 might increase the risk in HCC patients infected with hepatitis virus(OR=2.568, 95%CI=0.054-121.69).Besides,the homozygous MDM2-SNP309 genotype did not exhibit a significantly earlier age of onset for HCC. CONCLUSION:Current data suggest that the asso- ciation between MDM2-SNP309 GG genotype and HCC is not significant,while the risk may be enhanced in patients infected by hepatitis virus in Taiwan.

Attention Drawing of Movie Trailers Revealed by Electroencephography Using Sample Entropy

A movie trailer is a common advertising tool in the entertainment industry. Detection of a viewer’s brain responses to a movie trailer can help film producers to tailor a more appealing trailer of a movie. In this study, we acquired electroencephalographic (EEG) signals from subjects when they watched movie trailers (labeled as Movie session), and compared with their resting state session (labeled as Resting session) or when they watch nature scenes (labeled as Nature session). We used Sample Entropy (SampEn) to analyze the EEG signals between different sessions. Results showed that the complexity ratios at Fp1, Fp2 and Fz channels derived from Movie session were significantly lower than that in Resting state or when subjects watched Nature session (p < 0.001). Our results suggest that the brain status can affect the complexity of their EEG. Further, the attraction of attention of a movie trailer can be observed from the change of EEG.

The effects of ultrasound on blood-brain barrier

The brain is protected from the entry of foreign substances by blood-brain barrier (BBB), but becomes a barrier while chemotherapy is needed for the brain diseases. Ultrasound with microbubbles (MBs) has been shown to noninvasively increase the permeability of the BBB in the normal tissue and brain tumor. The real mechanism for disruption is still unknown. Hemorrhage was usually found in the sonicated region of the brain. Thus, treatment safety is the primary concern when considering clinical application of BBB disruption induced by ultrasound in the presence of MBs. Here we investigate the effects of ultrasound on the permeability of BBB whether the MBs were administered. The data reveals that Evans blue (EB) accumulation was highest in the brain after sonication with MBs. However, the permeability of BBB also can be significantly increased by ultrasound alone. These results demonstrated that noninvasive disruption of BBB by ultrasound alone with no damage is possible.

Ultrasound Mediated Delivery of Liposomal Doxorubicin in Mice with Glioma

Malignant brain tumors remain difficult to treat with chemotherapy because the blood–brain barrier (BBB) limits the amounts of potent agents that can reach the tumor, such that the drugs are unable to reach therapeutic dosage. Although various targeted carriers that encapsulate chemotherapeutic agents have been shown to improve drug delivery to brain tumors, the BBB is still a major obstacle in the use of chemotherapy for the treatment of these tumors. Human glioblastoma-bearing mice were injected intravenously with doxorubicin (Dox) encapsulated in atherosclerotic plaque-specific peptide-1 (AP-1)-conjugated liposomes or unconjugated liposome. These treatments took place with or without BBB disruption induced by transcranial pulsed high-intensity focused ultrasound (pulsed HIFU). This study showed that the treatment with Dox encapsulated in AP-1-conjugated liposomes followed by pulsed HIFU enhanced the accumulation of the cytotoxic drug in cells and inhibited the growth of brain tumors in vivo. Combining pulsed HIFU with cytotoxic agents might improve their efficacy in patients with brain tumors while simultaneously reducing the drug side effects. Further investigation is required to provide a comprehensive physical characterization of the sonication process and to determine its bioeffects.

Investigation of Bone Ratios for Prenatal Fetal Assessment in Taiwan Residents Population

The purpose of this study is to calculate the ratios of fetal limb bone to nasal bone length (NBL) obtained by transabdominal ultrasound between 19 and 28 weeks of gestation. Cross-sectional data were obtained from 1408 women with singleton pregnancies who underwent an advanced prenatal ultrasound examination from August 2006 to September 2008. The single measurement plane of fetal limb bones was on the longest section of each structure with appropriate image magnification. To assess repeatability of the intraobserver, two repeated measurements were obtained in 44 fetuses. The ratio of fetuses with biparietal diameter (BPD)/NBL was compared with those of fetal limb bones/NBL. The mean ratio was found between fetal NBL measurements and BPD (7.240), humerus length (HL) (4.807), radius length (RL) (4.157), ulna length (UL) (4.502), femur length (FL) (5.131), tibia length (TL) (4.528), and fibula length (FiL) (4.507). The reference ranges of fetal long bone length/NBL ratios for the second trimester was established by transabdominal sonography. There were no significant increases in these ratios with gestational age, especially the HL/NBL ratio.

POLARIZATION-SENSITIVE OPTICAL COHERENCE TOMOGRAPHY USING A MODIFIED BALANCE DETECTOR

In conventional polarization sensitive optical coherence tomography(PS-OCT),phase retar-dation is obtained by the amplitude of P and S polarization only,and the fast axis angle is obtained by the phase difference in P and S polarizations via Hilbert transformation.In this paper,we proposed a modifed PS OCT setup in which the phase retardation and fast axis angle are simply expressed as the function of the amplitude ofP and S polarization and their differential signal.Due to the common-path feature between the two channels ofP and S polarization,the fuctuation in the measurement of phase retardation and fast axis angle caused by excess noise and phase noise from the laser source can be reduced by the differential signal of P and S polarization via a modified balance detector.Thus,the signal of phase retardation and fast angle axis in the deep layer of a porcine sample can be improved.

Data Classification with Modified Density Weighted Distance Measure for Diffusion Maps

Clinical data analysis is of fundamental importance, as classifications and detailed characterizations of diseases help physicians decide suitable management for patients, individually. In our study, we adopt diffusion maps to embed the data into corresponding lower dimensional representation, which integrate the information of potentially nonlinear progressions of the diseases. To deal with nonuniformaity of the data, we also consider an alternative distance measure based on the estimated local density. Performance of this modification is assessed using artificially generated data. Another clinical dataset that comprises metabolite concentrations measured with magnetic resonance spectroscopy was also classified. The algorithm shows improved results compared with conventional Euclidean distance measure.