Potential Role of Lipase Activity on the Internal Exposure Assessment of Glycidol Released from Its Fatty Acid Esters.

Glycidyl fatty acid esters (GEs) can be found in food, and they can be converted into genotoxic animal carcinogen glycidol in vivo by the action of lipase. This study examined whether human ingestion of charbroiled pork containing high levels of GEs (300 µg/day) increased glycidol-hemoglobin adduct (diHOPrVal), a marker of internal exposure to glycidol using LC-MS/MS. Contrary to expectation, the diHOPrVal value before ingesting charbroiled pork was 3.11 ± 1.10 pmol/g globin, which slightly decreased to 2.48 ± 0.47 pmol/g globin after 5 days of consumption. The decrease in lipase activity caused by the continuous consumption of lipid-rich foods such as meat in humans might decrease internal exposure to glycidol released from its esters. Thus, lipase activity was measured in C57/BL6J mice fed a high-fat diet (HFD) for 8 weeks, and diHOPrVal formation was measured after the administration of glycidyl oleate. Lipase activity was significantly lower in the HFD group than in the normal diet group. The amount of diHOPrVal was reduced in the HFD group. Therefore, the lipase activity was reduced by HFD, thereby decreasing the degradation of glycidol from glycidyl oleate. These results indicate that changes in lipase activity depending on the amount of lipids in the diet may affect the assessment of GEs exposure, and monitoring the lipase activity would provide a comprehensive understanding of exposure assessment.

Comparative environmental RNA and DNA metabarcoding analysis of river algae and arthropods for ecological surveys and water quality assessment.

Environmental DNA (eDNA) metabarcoding is widely used for species analysis, while the use of environmental RNA (eRNA) metabarcoding is more limited. We conducted comparative eDNA/eRNA metabarcoding of the algae and arthropods (aquatic insects) in water samples from Naka River, Japan, to evaluate their potential for biological monitoring and water quality assessment. Both methods detected various algae and arthropod species; however, their compositions were remarkably different from those in traditional field surveys (TFSs), indicating low sensitivity. For algae, the species composition derived from eDNA and eRNA metabarcoding was equivalent. While TFSs focus on attached algae, metabarcoding analysis theoretically detects both planktonic and attached algae. A recently expanded genomic database for aquatic insects significantly contributed to the sensitivity and positive predictivity for arthropods. While the sensitivity of eRNA was lower than that of eDNA, the positive predictivity of eRNA was higher. The eRNA of terrestrial arthropods indicated extremely high or low read numbers when compared with eDNA, suggesting that eRNA could be an effective indicator of false positives. Arthropod and algae eDNA/eRNA metabarcoding analysis enabled water quality estimates from TFSs. The eRNA of algae and arthropods could thus be used to evaluate biodiversity and water quality and provide insights from ecological surveys.

Assessment of surgical skills by using surgical navigation in robot-assisted partial nephrectomy.

PURPOSE: To assess surgical skills in robot-assisted partial nephrectomy (RAPN) with and without surgical navigation (SN). METHODS: We employed an SN system that synchronizes the real-time endoscopic image with a virtual reality three-dimensional (3D) model for RAPN and evaluated the skills of two expert surgeons with regard to the identification and dissection of the renal artery (non-SN group, n = 21 [first surgeon n = 9, second surgeon n = 12]; SN group, n = 32 [first surgeon n = 11, second surgeon n = 21]). We converted all movements of the robotic forceps during RAPN into a dedicated vocabulary. Using RAPN videos, we classified all movements of the robotic forceps into direct action (defined as movements of the robotic forceps that directly affect tissues) and connected motion (defined as movements that link actions). In addition, we analyzed the frequency, duration, and occupancy rate of the connected motion. RESULTS: In the SN group, the R.E.N.A.L nephrometry score was lower (7 vs. 6, P = 0.019) and the time to identify and dissect the renal artery (16 vs. 9 min, P = 0.008) was significantly shorter. The connected motions of inefficient "insert," "pull," and "rotate" motions were significantly improved by SN. SN significantly improved the frequency, duration, and occupancy rate of connected motions of the right hand of the first surgeon and of both hands of the second surgeon. The improvements in connected motions were positively associated with SN for both surgeons. CONCLUSION: This is the first study to investigate SN for nephron-sparing surgery. SN with 3D models might help improve the connected motions of expert surgeons to ensure efficient RAPN.

Clinical usefulness of right ventricular 3D area strain in the assessment of treatment effects of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension: comparison with 2D feature-tracking MRI.

OBJECTIVES: To evaluate the usefulness of right ventricular (RV) area strain analysis via cardiac MRI (CMRI) as a tool for assessing the treatment effects of balloon pulmonary angioplasty (BPA) in inoperable chronic thromboembolic pulmonary hypertension (CTEPH), RV area strain was compared to two-dimensional (2D) strain with feature-tracking MRI (FTMRI) before and after BPA. METHODS: We retrospectively analyzed 21 CTEPH patients who underwent BPA. End-systolic global area strain (GAS), longitudinal strain (LS), circumferential strain (CS), and radial strain (RS) were measured before and after BPA. Changes in GAS and RV ejection fraction (RVEF) values after BPA were defined as ΔGAS and ΔRVEF. Receiver operating characteristic (ROC) analyses were performed to determine the optimal cutoff of the strain at after BPA for detection of improved patients with decreased mean pulmonary artery pressure (mPAP) less than 30 mmHg and increased RVEF more than 50%. RESULTS: ROC analysis revealed the optimal cutoffs of strains (GAS, LS, CS, and RS) for identifying improved patients with mPAP < 30 mmHg (cutoff (%) = - 41.2, - 13.8, - 16.7, and 14.4: area under the curve, 0.75, 0.56, 0.65, and 0.75) and patients with RVEF > 50% (cutoff (%) = - 37.2, - 29.5, - 2.9, and 14.4: area under the curve, 0.81, 0.60, 0.56, and 0.56). CONCLUSIONS: Area strain analysis via CMRI may be a more useful tool for assessing the treatment effects of BPA in patients with CTEPH than 2D strains with FTMRI. KEY POINTS: • Area strain values can detect improvement of right ventricular (RV) pressure and function after balloon pulmonary angioplasty (BPA) equally or more accurately than two-dimensional strains. • Area strain analysis is a useful analytical method that reflects improvements in complex RV myocardial deformation by BPA. • Area strain analysis is a robust method with reproducibility equivalent to that of 2D strain analysis.

A decision tree-based integrated testing strategy for tailor-made carcinogenicity evaluation of test substances using genotoxicity test results and chemical spaces.

Genotoxicity evaluation has been widely used to estimate the carcinogenicity of test substances during safety evaluation. However, the latest strategies using genotoxicity tests give more weight to sensitivity; therefore, their accuracy has been very low. For precise carcinogenicity evaluation, we attempted to establish an integrated testing strategy for the tailor-made carcinogenicity evaluation of test materials, considering the relationships among genotoxicity test results (Ames, in vitro mammalian genotoxicity and in vivo micronucleus), carcinogenicity test results and chemical properties (molecular weight, logKow and 179 organic functional groups). By analyzing the toxicological information and chemical properties of 230 chemicals, including 184 carcinogens in the Carcinogenicity Genotoxicity eXperience database, a decision tree for carcinogenicity evaluation was optimised statistically. A decision forest model was generated using a machine-learning method-random forest-which comprises thousands of decision trees. As a result, balanced accuracies in cross-validation of the optimised decision tree and decision forest model, considering chemical space (71.5% and 75.5%, respectively), were higher than balanced accuracy of an example regulatory decision tree (54.1%). Moreover, the statistical optimisation of tree-based models revealed significant organic functional groups that would cause false prediction in standard genotoxicity tests and non-genotoxic carcinogenicity (e.g., organic amide and thioamide, saturated heterocyclic fragment and aryl halide). In vitro genotoxicity tests were the most important parameters in all models, even when in silico parameters were integrated. Although external validation is required, the findings of the integrated testing strategies established herein will contribute to precise carcinogenicity evaluation and to determine new mechanistic hypotheses of carcinogenicity.

Exposure assessment of process-related contaminants in food by biomarker monitoring.

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario's and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment.

Mechanism-based risk assessment strategy for drug-induced cholestasis using the transcriptional benchmark dose derived by toxicogenomics.

Cholestasis is one of the major causes of drug-induced liver injury (DILI), which can result in withdrawal of approved drugs from the market. Early identification of cholestatic drugs is difficult due to the complex mechanisms involved. In order to develop a strategy for mechanism-based risk assessment of cholestatic drugs, we analyzed gene expression data obtained from the livers of rats that had been orally administered with 12 known cholestatic compounds repeatedly for 28 days at three dose levels. Qualitative analyses were performed using two statistical approaches (hierarchical clustering and principle component analysis), in addition to pathway analysis. The transcriptional benchmark dose (tBMD) and tBMD 95% lower limit (tBMDL) were used for quantitative analyses, which revealed three compound sub-groups that produced different types of differential gene expression; these groups of genes were mainly involved in inflammation, cholesterol biosynthesis, and oxidative stress. Furthermore, the tBMDL values for each test compound were in good agreement with the relevant no observed adverse effect level. These results indicate that our novel strategy for drug safety evaluation using mechanism-based classification and tBMDL would facilitate the application of toxicogenomics for risk assessment of cholestatic DILI.

Cost-effectiveness of EOB-MRI for Hepatocellular Carcinoma in Japan.

PURPOSE: The objective of the study was to evaluate the cost-effectiveness of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) in the diagnosis and treatment of hepatocellular carcinoma (HCC) in Japan compared with extracellular contrast media-enhanced MRI (ECCM-MRI) and contrast media-enhanced computed tomography (CE-CT) scanning. METHODS: A 6-stage Markov model was developed to estimate lifetime direct costs and clinical outcomes associated with EOB-MRI. Diagnostic sensitivity and specificity, along with clinical data on HCC survival, recurrence, treatment patterns, costs, and health state utility values, were derived from predominantly Japanese publications. Parameters unavailable from publications were estimated in a Delphi panel of Japanese clinical experts who also confirmed the structure and overall approach of the model. Sensitivity analyses, including one-way, probabilistic, and scenario analyses, were conducted to account for uncertainty in the results. FINDINGS: Over a lifetime horizon, EOB-MRI was associated with lower direct costs (¥2,174,869) and generated a greater number of quality-adjusted life years (QALYs) (9.502) than either ECCM-MRI (¥2,365,421, 9.303 QALYs) or CE-CT (¥2,482,608, 9.215 QALYs). EOB-MRI was superior to the other diagnostic strategies considered, and this finding was robust over sensitivity and scenario analyses. A majority of the direct costs associated with HCC in Japan were found to be costs of treatment. The model results revealed the superior cost-effectiveness of the EOB-MRI diagnostic strategy compared with ECCM-MRI and CE-CT. IMPLICATIONS: EOB-MRI could be the first-choice imaging modality for medical care of HCC among patients with hepatitis or liver cirrhosis in Japan. Widespread implementation of EOB-MRI could reduce health care expenditures, particularly downstream treatment costs, associated with HCC.

T1ρ mapping improvement using stretched-type adiabatic locking pulses for assessment of human liver function at 3T.

PURPOSE: The purpose of this study is to investigate the performance of stretched-type adiabatic spin lock pulses for homogeneous spin locking with a flexible spin lock time (TSL) setting. METHODS: T1ρ values were obtained from 61 patients and five normal volunteers who were categorized using the Child-Pugh classification and scanned using each spin lock pulse type. The pulses used were the block and two kinds of hyperbolic secant (HS); HS8_10, and HS8_5. Visual scoring was categorized using a four point scale (1:Severe, 2:Moderate, 3:Mild and 4:None) to evaluate the homogeneity of the T1ρ map and the source images obtained by each spin lock pulse. Mean T1ρ values among the patient groups with different Child-Pugh classification were compared. RESULTS: The visual assessment scores were 1.98 ± 1.05 for block pulse locking, 3.87 ± 0.39 for HS8_10 pulse locking, and 3.83 ± 0.45 for HS8_5 pulse locking, respectively. The scores between block pulse and HS8_10 were significantly different (p < 0.001), as were those between block pulse and HS8_5 (p < 0.001). The median T1ρ values of normal liver function, Child-Pugh A, and Child-Pugh B or C were 37.00 ms, 40.77 ms, and 42.20 ms for block pulse, 46.75 ms, 50.78 ms, and 55.60 ms for HS8_10, and 48.80 ms, 55.42 ms, and 57.80 ms for HS8_5, respectively. CONCLUSION: The spin locking sequence using stretched-type adiabatic pulses provides homogeneous liver T1ρ maps with reduced artifact and is necessary for a robust evaluation of liver function using T1ρ.

One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography.

OBJECTIVES: To investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements. METHODS: Twenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs-RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson's coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test. RESULTS: Qp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size. CONCLUSIONS: 256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively. KEY POINTS: • Quantification of left-to-right shunting can be performed reliably and accurately by CT. • The sizes of defects and rims can be measured accurately using 256-slice CT. • 256-slice CT permits pretreatment evaluation of ASD non-invasively and comprehensively.

Fibrosis in nonalcoholic fatty liver disease: Noninvasive assessment using computed tomography volumetry.

AIM: To evaluate the diagnostic performance of computed tomography (CT) volumetry for discriminating the fibrosis stage in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: A total of 38 NAFLD patients were enrolled. On the basis of CT imaging, the volumes of total, left lateral segment (LLS), left medial segment, caudate lobe, and right lobe (RL) of the liver were calculated with a dedicated liver application. The relationship between the volume percentage of each area and fibrosis stage was analyzed using Spearman's rank correlation coefficient. A receiver operating characteristic (ROC) curve analysis was performed to determine the accuracy of CT volumetry for discriminating fibrosis stage. RESULTS: The volume percentages of the caudate lobe and the LLS significantly increased with the fibrosis stage (r = 0.815, P < 0.001; and r = 0.465, P = 0.003, respectively). Contrarily, the volume percentage of the RL significantly decreased with fibrosis stage (r = -0.563, P < 0.001). The volume percentage of the caudate lobe had the best diagnostic accuracy for staging fibrosis, and the area under the ROC curve values for discriminating fibrosis stage were as follows: ≥ F1, 0.896; ≥ F2, 0.929; ≥ F3, 0.955; and ≥ F4, 0.923. The best cut-off for advanced fibrosis (F3-F4) was 4.789%, 85.7% sensitivity and 94.1% specificity. CONCLUSION: The volume percentage of the caudate lobe calculated by CT volumetry is a useful diagnostic parameter for staging fibrosis in NAFLD patients.

Clinical impact of left ventricular eccentricity index using cardiac MRI in assessment of right ventricular hemodynamics and myocardial fibrosis in congenital heart disease.

OBJECTIVES: To investigate the utility of eccentricity index (EI) using cardiac cine MRI for the assessment of right ventricular (RV) hemodynamics in congenital heart disease (CHD). METHODS: Fifty-five patients with CHD (32 women; mean age, 40.7 ± 20.9 years) underwent both cardiac MRI and right heart catheterization. EI was defined as the ratio of the distance between the anterior-posterior wall and the septal-lateral wall measured in the short-axis of mid-ventricular cine MRI. Correlations between EIs and RV hemodynamic parameters were analyzed. EIs were compared between patients with and without late gadolinium enhancement (LGE). RESULTS: A strong correlation between mean pulmonary artery pressure (PAP) and systolic EI (r = 0.81, p < 0.0001) and a moderate negative correlation between diastolic EI and RV ejection fraction (EF) (r = -0.62, p < 0.0001) were observed. Receiver operating characteristic analysis revealed optimal EI thresholds for detecting patients with mean PAP ≥40 mmHg with C-statistics of 0.90 and patients with RVEF <40 % with C-statistics of 0.78. Systolic EIs were significantly greater for patients with LGE (1.45 ± 0.05) than for those without LGE (1.15 ± 0.07; p < 0.001). CONCLUSIONS: EI offers a simple, comprehensive index that can predict pulmonary hypertension and RV dysfunction in CHD. KEY POINTS: • EI offers a simple and comprehensive index of RV hemodynamics. • EI could predict pulmonary hypertension and RV dysfunction. • Left ventricular deformation expressed as high EI is related to myocardial fibrosis.

Quantitative assessment of right ventricular function and pulmonary regurgitation in surgically repaired tetralogy of Fallot using 256-slice CT: comparison with 3-Tesla MRI.

OBJECTIVES: To compare 256-slice cardiac computed tomography (CCT) with cardiac magnetic resonance (CMR) imaging to assess right ventricular (RV) function and pulmonary regurgitant fraction (PRF) in patients with repaired tetralogy of Fallot (TOF). METHODS: Thirty-three consecutive patients with repaired TOF underwent retrospective ECG-gated CCT and 3-Tesla CMR. RV and left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were measured using CCT and CMR. PRF-CCT (%) was defined as (RVSV - LVSV)/RVSV. PRF-CMR (%) was measured by the phase-contrast method. Repeated measurements were performed to determine intra- and interobserver variability. RESULTS: CCT measurements, including PRF, correlated highly with the CMR reference (r = 0.71-0.96). CCT overestimated RVEDV (mean difference, 17.1 ± 2.9 ml), RVESV (12.9 ± 2.1 ml) and RVSV (4.2 ± 2.0 ml), and underestimated RVEF (-2.6 ± 1.0%) and PRF (-9.1 ± 2.0%) compared with CMR. The limits of agreement between CCT and CMR were in a good range for all measurements. The variability in CCT measurements was lower than those in CMR. The estimated effective radiation dose was 7.6 ± 2.6 mSv. CONCLUSIONS: 256-slice CCT can assess RV function and PRF with relatively low dose radiation exposure in patients with repaired TOF, but overestimates RV volume and underestimates PRF. KEY POINTS: 256-slice CT assessment of RV function is highly reproducible in repaired TOF. Pulmonary regurgitation can be evaluated by biventricular systolic volume difference. CT overestimates RV volume and underestimates pulmonary regurgitation, compared with MRI.

Recent advances in radiation oncology: intensity-modulated radiotherapy, a clinical perspective.

Radiotherapy plays an important role in the treatment of various malignancies, and intensity-modulated radiotherapy (IMRT) is an attractive option because it can deliver precise conformal radiation doses to the target while minimizing the dose to adjacent normal tissues. IMRT provides a highly conformal dose distribution by modulating the intensity of the radiation beam. A number of malignancies have been targeted by IMRT; this work reviews published data on the major disease sites treated with IMRT. The dosimetric advantage of IMRT has resulted in the significant reduction of adverse effects in some tumors. However, there are few clinical trials comparing IMRT and three-dimensional conformal radiotherapy (3D-CRT), and no definite increase in survival or the loco-regional control rate by IMRT has been demonstrated in many malignancies. IMRT also requires greater time and resources to complete compared to 3D-CRT. In addition, the cost-effectiveness of IMRT versus 3D-CRT has not yet been established.

Relationship between impaired cardiac sympathetic activity and spatial dyssynchrony in patients with non-ischemic heart failure: assessment by MIBG scintigraphy and tagged MRI.

BACKGROUND: Impairment of cardiac sympathetic activity has various detrimental effects on cardiac function. The purpose was to investigate the relationship between left ventricular (LV) dyssynchrony and cardiac sympathetic activity in non-ischemic heart failure (HF). METHODS: Twenty-seven patients with non-ischemic HF were enrolled. Cardiac sympathetic activity was assessed by heart-to-mediastinum ratio (H/M ratio) on (123)I-Metaiodobenzylguanidine scintigraphy. LV dyssynchrony was assessed by cross-correlation analysis of time curves of myocardial circumferential strains delivered from cine-tagging MR images. Temporal dyssynchrony was defined as contraction delay between septal and lateral segments >110 milliseconds. Spatial dyssynchrony was defined as the negative value of the maximum correlation for the two strain time curves. RESULTS: H/M ratio was significantly lower for patients with spatial dyssynchrony compared to patients without (1.8 ± 0.3 vs 2.1 ± 0.3, P < .05). There was no difference between patients with and without temporal dyssynchrony (2.0 ± 0.2 vs 2.0 ± 0.3). The incidence of spatial dyssynchrony was significantly higher in patients with H/M ratio <2.0 than those whose ratios were ≥2.0 (75% vs 20%, P = .001). There was no difference in the incidence of temporal dyssynchrony between the two groups (17% vs 20%). CONCLUSION: Impairment of cardiac sympathetic activity was found to be associated with spatial dyssynchrony in patients with non-ischemic HF.

Differentiating primary CNS lymphoma from glioblastoma multiforme: assessment using arterial spin labeling, diffusion-weighted imaging, and ¹8F-fluorodeoxyglucose positron emission tomography.

INTRODUCTION: Our purpose was to evaluate the diagnostic performance of arterial spin labeling (ASL) perfusion imaging, diffusion-weighted imaging (DWI), and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating primary central nervous system lymphomas (PCNSLs) from glioblastoma multiformes (GBMs). METHODS: Fifty-six patients including 19 with PCNSL and 37 with GBM were retrospectively studied. From the ASL data, an absolute tumor blood flow (aTBF) and a relative tumor blood flow (rTBF) were obtained within the enhancing portion of each tumor. In addition, the minimum apparent diffusion coefficient (ADCmin) and the maximum standard uptake value (SUVmax) were obtained from DWI and FDG-PET data, respectively. Each of the four parameters was compared between PCNSLs and GBMs using Kruskal-Wallis test. The performance in discriminating between PCNSLs and GBMs was evaluated using the receiver-operating characteristics analysis. Area-under-the-curve (AUC) values were compared among the four parameters using a nonparametric method. RESULTS: The aTBF, rTBF, and ADCmin were significantly higher in GBMs (mean aTBF ± SD = 91.6 ± 56.0 mL/100 g/min, mean rTBF ± SD = 2.61 ± 1.61, mean ADCmin ± SD = 0.78 ± 0.19 × 10(-3) mm(2)/s) than in PCNSLs (mean aTBF ± SD = 37.3 ± 10.5 mL/100 g/min, mean rTBF ± SD = 1.24 ± 0.37, mean ADCmin ± SD = 0.61 ± 0.13 × 10(-3) mm(2)/s) (p < 0.005, respectively). In addition, SUVmax was significantly lower in GBMs (mean ± SD = 13.1 ± 6.34) than in PCNSLs (mean ± SD = 22.5 ± 7.83) (p < 0.005). The AUC for aTBF (0.888) was higher than those for rTBF (0.810), ADCmin (0.768), and SUVmax (0.848), although their difference was not statistically significant. CONCLUSION: ASL perfusion imaging is useful for differentiating PCNSLs from GBMs as well as DWI and FDG-PET.

Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR.

BACKGROUND: The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. METHODS: 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. RESULTS: The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86. CONCLUSIONS: Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.

Contrast-enhanced MDCT gastrography for detection of early gastric cancer: Initial assessment of "wall-carving image", a novel volume rendering technique.

OBJECTIVE: We developed a new volume rendering technique, the CT gastrography wall carving image (WC) technique, which provides a clear visualization of localized enhanced tumors in the gastric wall. We evaluated the diagnostic performance of the WC as an adjunct to conventional images in detecting early gastric cancer (EGC). MATERIALS AND METHODS: Thirty-nine patients with 43 EGCs underwent contrast-enhanced MDCT gastrography for preoperative examination. Two observers independently reviewed the images under three different conditions: term 1, Axial CT; term 2, Axial CT, MPR and VE; and term 3, Axial CT, MPR, VE and WC for the detection of EGC. The accuracy of each condition as reviewed by each of the two observers was evaluated by receiver operating characteristic analysis. Interobserver agreement was calculated using weighted-κ statistics. RESULTS: The best diagnostic performance and interobserver agreement were obtained in term 3. The AUCs of the two observers for terms 1, 2, and 3 were 0.63, 0.73, and 0.84, and 0.57, 0.73, and 0.76, respectively. The interobserver agreement improved from fair at term 1 to substantial at term 3. CONCLUSIONS: The addition of WC to conventional MDCT display improved the diagnostic accuracy and interobserver reproducibility for the detection of ECG. WC represents a suitable alternative for the visualization of localized enhanced tumors in the gastric wall.