Pleural Tags on CT Scans to Predict Visceral Pleural Invasion of Non-Small Cell Lung Cancer That Does Not Abut the Pleura.

PURPOSE: To evaluate the association of pleural tags with visceral pleural invasion of non-small cell lung cancer (NSCLC) that does not abut the pleural surface. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board. Informed consent was waived. The study of NSCLC that does not abut the pleura in 141 patients (44 patients [31.2%] with visceral pleural invasion proved by pathologic analysis and 97 patients [68.8%] without pleural invasion) was conducted at a single tertiary center. The pleural tags were classified into three types (type 1, one or more linear pleural tag; type 2, one or more linear pleural tag with soft tissue component at the pleural end; and type 3, one or more soft tissue cord-like pleural tag) and prioritized into types 3, 2, and 1 when more than one type was present. Diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (LR) were calculated. RESULTS: In the absence of pleural tags, no pleural invasion was found. The presence of type 2 pleural tags was moderately associated with visceral pleural invasion with the following results: positive LR, 5.06; accuracy, 71%; sensitivity, 36.4%; specificity, 92.8%; PPV, 76.2%; and NPV, 69.6%. Type 1 pleural tags provided weak evidence to rule out visceral pleural invasion (positive LR, 0.38). Type 3 pleural tags indicated minimal increase in the likelihood of visceral pleural invasion (positive LR, 1.68). CONCLUSION: Type 2 pleural tags on conventional CT images can increase the accuracy of early diagnosis of visceral pleural invasion by NSCLC that does not abut the pleura.

Diagnostic Performance of Split-Bolus Portal Venous Phase Dual-Energy CT Urography in Patients With Hematuria.

OBJECTIVE: The purpose of this study is to evaluate the diagnostic performance of split-bolus portal venous phase dual-energy CT (DECT) urography in patients with hematuria. MATERIALS AND METHODS: True unenhanced and split-bolus portal venous phase contrast-enhanced weighted-average images were obtained in 171 patients with hematuria. Virtual unenhanced and iodine-overlay images were reconstructed from contrast-enhanced 80-kVp and tin-filtered 140-kVp scans. Images were independently reviewed by two radiologists who were blinded to the final diagnoses in two separate reading sessions: virtual unenhanced and iodine-overlay images (single phase) in the first session and true unenhanced and contrast-enhanced weighted-average images (dual phase) in the second session (mean ± SD, 52 ± 8 days later). Sensitivity, specificity, and accuracy of mass detection were calculated from the data of both reading sessions. The number of calculi detected on virtual unenhanced images was compared with the number detected on true unenhanced images. The difference in radiation dose between the single- and dual-phase protocols was calculated. The statistical significance was determined by ANOVA. RESULTS: The sensitivity, specificity, and accuracy were 98.7%, 98.9%, and 98.8%, respectively, for the single-phase approach to malignant mass detection and 98.7%, 97.9%, and 98.3%, respectively, for the dual-phase approach (p > 0.05 for all comparisons). The overall sensitivity of stone detection was 86.7% (39/45) for virtual unenhanced images. Omitting the unenhanced scan reduced the mean radiation dose from 15.4 to 6.7 mSv. CONCLUSION: The diagnostic performance of both the single- and dual-phase approaches of portal venous phase split-bolus DECT urography is equally good in patients with hematuria, and single-phase acquisition has the added benefit of radiation reduction.

Altered Functional Connectivity of the Insula and Nucleus Accumbens in Internet Gaming Disorder: A Resting State fMRI Study.

AIMS: A possible addiction mechanism has been represented by altered functional connectivity (FC) in the resting state. The aim of this study was to evaluate the FCs of the insula and nucleus accumbens among subjects with Internet gaming disorder (IGD). METHODS: We recruited 30 males with IGD and 30 controls and evaluated their FC using functional magnetic imaging scanning under resting, a state with relaxation, closed eyes, with inducement to think of nothing systematically, become motionless, and instructed not to fall asleep. RESULTS: Subjects with IGD had a lower FC with the left insula over the left dorsolateral prefrontal cortex (DLPFC) and orbital frontal lobe and a higher FC with the insula with the contralateral insula than controls. The inter-hemispheric insula connectivity positively correlated with impulsivity. Further, they had lower FC with the left nucleus accumbens over the left DLPFC and with the right nucleus accumbens over the left DLPFC, and insula and a higher FC with that over the right precuneus. CONCLUSION: The elevated inter-hemispheric insula FC is found to be associated with impulsivity and might explain why it is involved in IGD. The attenuated frontostriatal suggests that the emotion-driven gaming urge through nucleus accumbens could not be well regulated by the frontal lobe of subjects with IGD.

Split-Bolus Portal Venous Phase Dual-Energy CT Urography: Protocol Design, Image Quality, and Dose Reduction.

OBJECTIVE: The purpose of this study is to evaluate the image quality of split-bolus portal venous phase urography and the potential reduction of radiation dose by using a second-generation dual-source dual-energy CT (DECT) scanner. MATERIALS AND METHODS: DECT urography was performed in 84 patients. Unenhanced CT was performed 20 minutes after drinking 800 mL of water. The split-bolus protocol consisted of a sequence of injections, as follows: 200 mL of normal saline (2.0 mL/s), 50 mL of contrast medium (2.5 mL/s) at 0 second, 70 mL of contrast medium (2.5 mL/s) at 360 seconds, and a saline flush of 25 mL. The scan was started at 420 seconds. Virtual unenhanced images were reconstructed from contrast-enhanced images. The mean CT density and signal-to-noise ratio (SNR) of the renal parenchyma, vessels, upper urinary tract, normal reference tissues, and tumors were measured for image quantitative analysis. Image quality and opacification of the collecting systems were rated by two radiologists using 3- or 4-point scales. RESULTS: The SNR of all measured sites, except the renal pelvis, showed a statistically significant correlation (p < 0.001) between the true unenhanced and virtual unenhanced images. The overall sensitivity of stone detection was 87.5% (28/32) in virtual unenhanced images. Image quality of the renal parenchyma, arteries, and veins was excellent in 59.5%, 75.0%, and 97.6% of cases, respectively. Opacification of the intrarenal collecting systems, proximal, middle, and distal ureters, and bladder was complete in 92.9%, 83.9%, 78.6%, 77.4%, and 26.2% of patients, respectively. Omitting the unenhanced scan can reduce the mean radiation dose from 15.6 to 6.7 mSv. CONCLUSION: Portal venous phase split-bolus DECT urography provides sufficient image quality with potential to reduce radiation exposure.

Lowering radiation dose during dedicated colorectal cancer MDCT: comparison of low tube voltage and sinogram-affirmed iterative reconstruction at 80 kVp versus blended dual-energy images in a population of patients with low body mass index.

PURPOSE: To assess the diagnostic accuracy, cancer staging, image quality, and radiation dose of 80-kVp computed tomography (CT) images for patients with colorectal cancers (CRCs) using sinogram-affirmed iterative reconstruction (SAFIRE). METHODS: Sixty-four consecutive patients (mean weight 62.5  ±  11.3 kg, mean BMI 24.1  ±  3.3 kg/m(2)) with known CRC underwent dual-energy CT. Data were reconstructed as a weighted average (WA) 120-kVp dataset. Both filtered back projection (FBP) and SAFIRE were applied to reconstruct the WA 120-Kvp (Protocol A, B) and 80-kVp (Protocol C, D) image sets. The image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the cancers, the normal reference tissues, and the effective dose for each protocol were assessed. The cancer detection, staging, and image quality were evaluated. Analysis of variance was used for statistical analysis. RESULTS: Compared with the FBP datasets at WA 120-kVp (Protocol A) and 80-kVp (Protocol C), the SAFIRE-reconstructed images (Protocols B, D) demonstrated significantly lower image noise (P  <  0.0083). Protocol D yielded significantly higher CNRs and SNRs for the CRCs and normal reference tissues than did Protocols A and C (P  <  0.0083). Protocol D also exhibited a significantly higher CNR for the CRC and some normal reference tissues than did Protocol B (P  <  0.0083). For hypovascular liver metastases (n  =  10), Protocol D yielded better SNRs and significantly higher CNRs than did Protocol A (P  <  0.0083). Overall, accuracy for tumor staging and liver metastasis was 95.3% (61/64) and 100%, respectively, in all of the 4 protocols. The mean effective dose decreased 41% from the WA 120-kVp to the 80-kVp protocols (6.23 vs. 3.68 mSv). CONCLUSIONS: The 80-kVp technique with SAFIRE provided high SNR, high CNR, and good accuracy for staging in nonobese patients with CRC. Our study results should be extrapolated to patient populations with a high BMI with caution. Further studies of high BMI patients are therefore warranted.

Computer-aided detection system for chest radiography: reducing report turnaround times of examinations with abnormalities.

BACKGROUND: The ability to give high priority to examinations with pathological findings could be very useful to radiologists with large work lists who wish to first evaluate the most critical studies. A computer-aided detection (CAD) system for identifying chest examinations with abnormalities has therefore been developed. PURPOSE: To evaluate the effectiveness of a CAD system on report turnaround times of chest examinations with abnormalities. MATERIAL AND METHODS: The CAD system was designed to automatically mark chest examinations with possible abnormalities in the work list of radiologists interpreting chest examinations. The system evaluation was performed in two phases: two radiologists interpreted the chest examinations without CAD in phase 1 and with CAD in phase 2. The time information recorded by the radiology information system was then used to calculate the turnaround times. All chest examinations were reviewed by two other radiologists and were divided into normal and abnormal groups. The turnaround times for the examinations with pathological findings with and without the CAD system assistance were compared. RESULTS: The sensitivity and specificity of the CAD for chest abnormalities were 0.790 and 0.697, respectively, and use of the CAD system decreased the turnaround time for chest examinations with abnormalities by 44%. CONCLUSION: The turnaround times required for radiologists to identify chest examinations with abnormalities could be reduced by using the CAD system. This system could be useful for radiologists with large work lists who wish to first evaluate the most critical studies.

Brain correlates of response inhibition in Internet gaming disorder.

AIMS: The present study aimed to evaluate the brain correlates of response inhibition among subjects with Internet gaming disorder (IGD). METHODS: For this purpose, 15 men with IGD for at least 1 year, and 15 controls with no history of IGD were recruited to perform the Go/Nogo task under functional magnetic resonance imaging investigation. Prior to scanning, the subjects were assessed using the Chen Internet Addiction Scale and the Barrett Impulsivity Scale. RESULTS: The control group exhibited activation of the right supplement motor area (SMA), dorsolateral prefrontal cortex, and caudate for response inhibition. However, the IGD group had a higher impulsivity and lower activity of the right SMA/pre-SMA in comparison to the control group. CONCLUSIONS: The results obtained suggest that dysfunctional activation of the SMA for response inhibition is one of the candidate mechanisms of IGD.

Altered brain activation during response inhibition and error processing in subjects with Internet gaming disorder: a functional magnetic imaging study.

The aim of the present study was to evaluate the impulsivity and brain correlates of response inhibition and error processing among subjects with Internet gaming disorder (IGD). We evaluated the response inhibition and error processing by functional magnetic resonance imaging (fMRI) in subjects with IGD and controls. Twenty-six men with IGD for at least 2 years and 23 controls with no history of IGD were recruited as the IGD and control groups, respectively. All subjects performed the event-related designed Go/No-go task under fMRI and completed questionnaires related to Internet addiction and impulsivity. The IGD group exhibited a higher score for impulsivity than the control group. The IGD group also exhibited higher brain activation when processing response inhibition over the left orbital frontal lobe and bilateral caudate nucleus than controls. Both the IGD and control groups exhibited activation of the insula and anterior cingulate cortex during error processing. The activation over the right insula was lower in the subjects with IGD than the control group. Our results support the fact that the fronto-striatal network involved in response inhibition, and the salience network, anchored by the anterior cingulate and insula, contributes to error processing. Further, adults with IGD have impaired insular function in error processing and greater activation of the fronto-striatal network in order to maintain their response inhibition performance.

Altered neurochemical metabolites in Alzheimer's disease patients with unawareness of deficits.

BACKGROUND: Unawareness of deficits is common and is associated with poor outcomes in Alzheimer's disease (AD); however, little is known about correlated neurobiochemical changes. METHODS: Proton magnetic resonance spectroscopy was used to examine neurobiochemical correlates of unawareness of deficits as assessed by the Dementia Deficit Scale in 36 patients with AD. Magnetic resonance spectroscopy spectra were acquired from the anterior cingulate area and right orbitofrontal area. Concentrations of N-acetyl-aspartate (NAA), total creatine, and other neurometabolites were calculated. RESULTS: Nineteen (52.8%) participants had relative unawareness of deficits. This condition was negatively correlated with NAA/creatine in the anterior cingulate area (ß = -0.36, p = 0.025) and positively correlated with NAA/creatine in the right orbitofrontal area (ß = 0.41, p = 0.009) after controlling for dementia severity. CONCLUSIONS: These findings suggest unawareness of deficits in AD was associated with the altered neurochemical metabolites in the anterior cingulate area and right orbitofrontal area. However, the two areas might have opposite neuronal functions in unawareness of deficits.

Brain activation deficit in increased-load working memory tasks among adults with ADHD using fMRI.

Working memory (WM) is impaired among adults with attention-deficit hyperactivity disorder (ADHD). This study aimed to investigate the brain activation deficit for low-level or increased-load WM among adults with ADHD. A total of 20 adults with ADHD and controls were recruited according to diagnostic interviewing by a psychiatrist. Phonological and visual-spatial 2-back and 3-back tasks were performed under functional magnetic resonance scanning. The results demonstrated that both the adults with ADHD and the controls exhibited activation of the fronto-parietal network for WM, and the intensity was greater in the adult ADHD group. The ADHD group had higher brain activation over the bilateral anterior cingulate, left inferior frontal lobe, hippocampus, and supplementary motor area (SMA) for phonological WM than the control group. When the task loading increased from 2-back to 3-back tasks, the adults with ADHD perceived greater difficulty. The control group exhibited increased brain activation over the frontal-parietal network in response to increased phonological WM load. However, the ADHD group showed decreased brain activation over the left precuneus, insula, and SMA. Further analysis demonstrated that the ADHD group exhibited a greater decrease in brain activation over the left fronto-parietal network, including the precuneus, SMA, insula/inferior frontal lobe, and dorsolateral prefrontal cortex, than the control group. These results suggest that adults with ADHD pay more effort to low demanding phonological WM. On the other hand, brain activation of the left fronto-parietal network is impaired when the demands of WM exceed the capacity of adults with ADHD.

Brain correlates of craving for online gaming under cue exposure in subjects with Internet gaming addiction and in remitted subjects.

This study aimed to evaluate brain correlates of cue-induced craving to play online games in subjects with Internet gaming addiction (IGA), subjects in remission from IGA and controls. The craving response was assessed by event-related design of functional magnetic resonance images (fMRIs). Fifteen subjects with IGA, 15 in remission from IGA and 15 controls were recruited in this study. The subjects were arranged to view the gaming screenshots and neutral images under investigation of fMRIs. The results showed that bilateral dorsolateral prefrontal cortex (DLPFC), precuneus, left parahippocampus, posterior cingulate and right anterior cingulate were activated in response to gaming cues in the IGA group and their activation was stronger in the IGA group than those in the control group. Their region-of-interest was also positively correlated with subjective gaming urge under cue exposure. These activated brain areas represent the brain circuit corresponding to the mechanism of substance use disorder. Thus, it would suggest that the mechanism of IGA is similar to substance use disorder. Furthermore, the IGA group had stronger activation over right DLPFC and left parahippocampus than did the remission group. The two areas would be candidate markers for current addiction to online gaming and should be investigated in future studies.

Development of a Gd(III)-based receptor-induced magnetization enhancement (RIME) contrast agent for ß-glucuronidase activity profiling.

ß-Glucuronidase is a key lysosomal enzyme and is often overexpressed in necrotic tumor masses. We report here the synthesis of a pro receptor-induced magnetization enhancement (pro-RIME) magnetic resonance imaging (MRI) contrast agent ([Gd(DOTA-FPßGu)]) for molecular imaging of ß-glucuronidase activity in tumor tissues. The contrast agent consists of two parts, a gadolinium complex and a ß-glucuronidase substrate (ß-d-glucopyranuronic acid). The binding association constant (KA) of [Gd(DOTA-FPßGu)] is 7.42 × 10(2), which is significantly lower than that of a commercially available MS-325 (KA = 3.0 × 10(4)) RIME contrast agent. The low KA value of [Gd(DOTA-FPßGu)] is due to the pendant ß-d-glucopyranuronic acid moiety. Therefore, [Gd(DOTA-FPßGu)] can be used for detection of ß-glucuronidase through RIME modulation. The detail mechanism of enzymatic activation of [Gd(DOTA-FPßGu)] was elucidated by LC-MS. The kinetics of ß-glucuronidase catalyzed hydrolysis of [Eu(DOTA-FPßGu)] at pH 7.4 best fit the Miechalis-Menten kinetic mode with Km = 1.38 mM, kcat = 3.76 × 10(3), and kcat/Km = 2.72 × 10(3) M(-1) s(-1). The low Km value indicates high affinity of ß-glucuronidase for [Gd(DOTA-FPßGu)] at physiological pH. Relaxometric studies revealed that T1 relaxivity of [Gd(DOTA-FPßGu)] changes in response to the concentration of ß-glucuronidase. Consistent with the relaxometric studies, [Gd(DOTA-FPßGu)] showed significant change in MR image signal in the presence of ß-glucuronidase and HSA. In vitro and in vivo MR images demonstrated appreciable differences in signal enhancement in the cell lines and tumor xenografts in accordance to their expression levels of ß-glucuronidase.

Subtypes of mild cognitive impairment among the elderly with major depressive disorder in remission.

BACKGROUND: Cognitive impairment in remitted late-life depression varies and might be associated with greater risk of dementia in some individuals. This study aimed to classify the subtypes of mild cognitive impairment (MCI) in late-life major depressive disorder in remission and to examine their clinical correlates and structural magnetic resonance imaging (MRI) features. METHODS: Elderly patients with major depressive disorder in remission and elderly comparisons were examined by a comprehensive battery of cognitive tasks. Proposed diagnostic criteria were used for MCI classification, and the degree of brain atrophy and white matter hyperintensity on MRI were evaluated. RESULTS: We found information-processing speed and memory were independent cognitive domains associated with late-life remitted major depressive disorder. Of the study cohort, 52.3% met the definition of MCI, including 28.5% with amnestic MCI (aMCI) and 23.8% with nonamnestic MCI (naMCI). A clinical correlate of aMCI was the late-onset of disorder (OR = 4.76; 95% CI = 1.57, 14.40) and of naMCI was a higher score on the Framingham stroke risk scale (OR = 1.39; 95% CI = 1.12, 1.72). The odds ratio of highest quartile of ventricular atrophy for aMCI compared to the comparisons was 3.65 (95% CI = 1.22, 10.96). CONCLUSIONS: The central cognitive impairments among the elderly with major depressive disorder in remission were memory and information-processing speed, and over half of the subjects met the MCI diagnostic criteria. Different risk factors existed for the subtypes of aMCI and naMCI. Later-age onset of first episode and ventricular atrophy were associated with aMCI, whereas vascular risk factor were associated with naMCI. We suggest there were different pathogeneses between aMCI and naMCI in late-life major depressive disorder.

Brain biochemical correlates of the plasma homocysteine level: a proton magnetic resonance spectroscopy study in the elderly subjects.

BACKGROUND: An elevated plasma homocysteine level has been reported to be associated with various neuropsychiatric diseases. However, little is known about the brain biochemical changes associated with the higher plasma homocysteine level. The main goal of this study was to examine the sex difference in brain biochemical concentrations using brain proton magnetic resonance spectroscopy (H MRS), and to elucidate the biochemical changes associated with plasma homocysteine levels by sex in healthy elderly subjects. METHODS: Seventy elderly subjects without any clinical psychiatric and neurological disease underwent 3-T brain H MRS. MRS spectra were acquired from voxels placed on the left side of the basal ganglia, frontal lobe, and hippocampus. Brain biochemical concentrations were compared between the elderly male and female participants. Correlations between these biochemical concentrations and plasma homocysteine levels by sex were analyzed. RESULTS: Female participants had significantly higher levels of choline in the left frontal lobe and hippocampus, and lower creatine and myo-inositol, in the left basal ganglia than did males. A higher homocysteine level was correlated with a lower N-acetylaspartate (NAA) concentration in the left hippocampus in elderly women (r = -0.44; p = 0.03) but not in elderly men. CONCLUSIONS: This study found that there was a sex difference in brain biochemical concentrations in the elderly participants. A higher plasma homocysteine level was associated with a lower NAA in the hippocampus of elderly women. The sex difference in association between brain biochemical concentrations and plasma homocysteine levels needs further investigation. We speculate that after menopause, women lose protection of estrogen from the neurotoxic effects of homocysteine in the hippocampus. Future studies are required to examine this speculation.

Zone-based analysis for automated detection of abnormalities in chest radiographs.

PURPOSE: The aim of this study was to develop an automated method for detection of local texture-based and density-based abnormalities in chest radiographs. METHODS: The method was based on profile analysis to detect abnormalities in chest radiographs. In the method, one density-based feature, Density Symmetry Index, and two texture-based features, Roughness Maximum Index and Roughness Symmetry Index, were used to detect abnormalities in the lung fields. In each chest radiograph, the lung fields were divided into four zones initially and then the method was applied to each zone separately. For each zone, Density Symmetry Index was obtained from the projection profile of each zone, and Roughness Maximum Index and Roughness Symmetry Index were obtained by measuring the roughness of the horizontal profiles via moving average technique. Linear discriminant analysis was used to classify normal and abnormal cases based on the three indices. The discriminant performance of the method was evaluated using ROC analysis. RESULTS: The method was evaluated on a database of 250 normal and 250 abnormal chest images. In the optimized conditions, the zone-based performance Az of the method for zones 1, 2, 3, and 4 were 0.917, 0.897, 0.892, and 0.814, respectively, and the case-based performance Az of the method was 0.842. Our previous method for detection of gross abnormalities was also evaluated on the same database. The case-based performance of our previous method was 0.689. CONCLUSIONS: In comparing the previous method and the new method proposed in this study, there was a great improvement by the new method for detection of local texture-based and density-based abnormalities. The new method combined with the previous one has potential for screening abnormalities in chest radiographs.

Synthesis and physicochemical characterization of carbon backbone modified [Gd(TTDA)(H2O)]2- derivatives.

The present study was designed to exploit optimum lipophilicity and high water-exchange rate (k(ex)) on low molecular weight Gd(III) complexes to generate high bound relaxivity (r(1)(b)), upon binding to the lipophilic site of human serum albumin (HSA). Two new carbon backbone modified TTDA (3,6,10-tri(carboxymethyl)-3,6,10-triazadodecanedioic acid) derivatives, CB-TTDA and Bz-CB-TTDA, were synthesized. The complexes [Gd(CB-TTDA)(H(2)O)](2-) and [Gd(Bz-CB-TTDA)(H(2)O)](2-) both display high stability constant (log K(GdL) = 20.28 and 20.09, respectively). Furthermore, CB-TTDA (log K(Gd/Zn) = 4.22) and Bz-CB-TTDA (log K(Gd/Zn) = 4.12) exhibit superior selectivity of Gd(III) against Zn(II) than those of TTDA (log K(Gd/Zn) = 2.93), EPTPA-bz-NO(2) (log K(Gd/Zn) = 3.19), and DTPA (log K(Gd/Zn) = 3.76). However, the stability constant values of [Gd(CB-TTDA)(H(2)O)](2-) and [Gd(Bz-CB-TTDA)(H(2)O)](2-) are lower than that of MS-325. The parameters that affect proton relaxivity have been determined in a combined variable temperature (17)O NMR and NMRD study. The water exchange rates are comparable for the two complexes, 232 × 10(6) s(-1) for [Gd(CB-TTDA)(H(2)O)](2-) and 271 × 10(6) s(-1) for [Gd(Bz-CB-TTDA)(H(2)O)](2-). They are higher than those of [Gd(TTDA)(H(2)O)](2-) (146 × 10(6) s(-1)), [Gd(DTPA)(H(2)O)](2-) (4.1 × 10(6) s(-1)), and MS-325 (6.1 × 10(6) s(-1)). Elevated stability and water exchange rate indicate that the presence of cyclobutyl on the carbon backbone imparts rigidity and steric constraint to [Gd(CB-TTDA)(H(2)O)](2-)and [Gd(Bz-CB-TTDA)(H(2)O)](2-). In addition, the major objective for selecting the cyclobutyl is to tune the lipophilicity of [Gd(Bz-CB-TTDA)(H(2)O)](2-). The binding affinity of [Gd(Bz-CB-TTDA)(H(2)O)](2-) to HSA was evaluated by ultrafiltration study across a membrane with a 30 kDa MW cutoff, and the first three stepwise binding constants were determined by fitting the data to a stoichiometric model. The binding association constants (K(A)) for [Gd(CB-TTDA)(H(2)O)](2-) and [Gd(Bz-CB-TTDA)(H(2)O)](2-) are 1.1 × 10(2) and 1.5 × 10(3), respectively. Although the K(A) value for [Gd(Bz-CB-TTDA)(H(2)O)](2-) is lower than that of MS-325 (K(A) = 3.0 × 10(4)), the r(1)(b) value, r(1)(b) = 66.7 mM(-1) s(-1) for [Gd(Bz-CB-TTDA)(H(2)O)](2-), is significantly higher than that of MS-325 (r(1)(b) = 47.0 mM(-1) s(-1)). As measured by the Zn(II) transmetalation process, the kinetic stabilities of [Gd(CB-TTDA)(H(2)O)](2-), [Gd(Bz-CB-TTDA)(H(2)O)](2-), and [Gd(DTPA)(H(2)O)](2-) are similar and are significantly higher than that of [Gd(DTPA-BMA)(H(2)O)](2-). High thermodynamic and kinetic stability and optimized lipophilicity of [Gd(CB-TTDA)(H(2)O)](2-) make it a favorable blood pool contrast agent for MRI.

In vivo MR/optical imaging for gastrin releasing peptide receptor of prostate cancer tumor using Gd-TTDA-NP-BN-Cy5.5.

Magnetic resonance imaging (MRI) has become the leading imaging tool for providing fine anatomical and physiology details. Optical imaging is offering a sensitive and specific method for in vivo molecular imaging of targeting molecules. The goal of this study is to design, synthesize, and characterize a new target-specific dual contrast agent for MR and optical imaging. Hence, [Gd(TTDA-NP)(H(2)O)](2-) was prepared and characterized. In addition, an 8-amino acid Bombesin analogue (BN) peptide substrate, which can target prostate, breast, and colon cancer, was synthesized by solid-phase peptide synthesis and subsequently conjugated with [Gd(TTDA-NP)(H(2)O)](2-) to form BN conjugated Gd-TTDA-NP-BN. The water-exchange rate (k(ex)(298)) for [Gd(TTDA-NP)(H(2)O)](2-) (110×10(6)s(-1)) is significantly higher than that of [Gd(DTPA)(H(2)O)](2-) complex and the rotational correlation time (τ(R)) for [Gd(TTDA-NP)(H(2)O)](2-) (145ps) is also higher than those of [Gd(TTDA)(H(2)O)](2-) (104ps) and [Gd(DTPA)(H(2)O)](2-) (103ps). The Gd-TTDA-NP-BN shows remarkable high relaxivity (7.12mM(-1)s(-1)) comparing to that of [Gd(TTDA-NP)(H(2)O)](2-). The fluorescence studies showed that the Gd-TTDA-NP-BN could efficiently enter PC-3 cells. Additionally, the human cancer cells xenografts using Gd-TTDA-NP-BN-Cy5.5 as an optical imaging probe clearly visualized subcutaneous PC-3 tumor and demonstrated its targeting ability to the gastrin releasing peptide (GRP) receptor overexpression. Furthermore, the biodistribution studies demonstrated significantly high tumor uptake (25.97±1.07% ID/g) and high tumor-to-normal tissue ratios at one hour post-injection of Gd-TTDA-NP-BN-Cy5.5 in the animal model. These results suggest that the Gd-TTDA-NP-BN-Cy5.5 is a superior probe for in vivo optical imaging. Importantly, the MR imaging studies showed notable signal enhancement (44.9±4.2%) on the tumor, indicating a high level accumulation of the contrast agent within the PC-3 tumor sites. Hence, targeting of prostate cancer cells was observed under in vitro and in vivo MR imaging studies using Gd-TTDA-NP-BN contrast agent. We conclude that Gd-TTDA-NP-BN and Gd-TTDA-NP-BN-Cy5.5 can be potentially used as the contrast agents for targeting GRP receptor overexpressing cells and tumors.

MDCT of giant gastric folds: differential diagnosis.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of MDCT in the differentiation of diseases involving giant gastric folds and to identify the features most useful for predicting the presence of malignant gastric disease. MATERIALS AND METHODS: Blinded reviewers retrospectively analyzed 16-MDCT scans of 64 patients who had endoscopic findings of giant gastric folds. Thirty of these patients had histopathologic results showing scirrhous carcinoma; 15, large B-cell lymphoma; 14, acute gastric mucosal lesions; and five, Ménétrier disease. Unenhanced transparent volume-rendered images were assessed to determine the morphologic features of the whole stomach. Contrast-enhanced images were used to analyze wall thickness, stratification, enhancement pattern, and perigastric conditions. We used the Cramer phi-prime correlation coefficient to calculate the overall diagnostic accuracy of MDCT in several gastric disorders. Scatterplot analysis was used for overall diagnostic score, and analysis of the receiver operator characteristic curves of the neighboring two diseases was used to locate the cutoff values for best diagnostic accuracy. We used exact logistic regression to identify which MDCT image features were most predictive of the presence of malignant gastric disease. RESULTS: The gastric wall was found to be significantly thicker in large B-cell lymphoma than in other disorders (p < 0.001). The overall diagnostic accuracy of MDCT in the four diseases was 100%. Loss of wall stratification was deemed the best MDCT predictor of the presence of malignancy. CONCLUSION: MDCT may be a reliable means of noninvasive diagnosis in the care of patients with endoscopically detected giant gastric folds and may be useful for differentiating benign from malignant disease.

The characteristics of decision making, potential to take risks, and personality of college students with Internet addiction.

This study aimed to identify risk factors involved in Internet addiction. A total of 216 college students (132 males and 84 females) were given the following: (a) the diagnostic interview for Internet addiction, (b) the Iowa gambling test for decision-making deficits, (c) the Balloon Analog Risk Test (BART) to assess risk-taking tendencies, and (d) the Tridimensional Personality Questionnaire (TPQ) for personality characteristics. The results revealed the following: (a) 49% of males and 17% of females were addicted, (b) the addicted students tended to select more advantageous cards in the last 40 cards of the Iowa test, indicating better decision making, (c) no difference was found for the BART, indicating that addicted subjects were not more likely to engage in risk-taking behaviors and (d) TPQ scores showed lower reward dependence (RD) and higher novelty seeking (NS) for the addicts. Their higher performance on the Iowa gambling test differentiates the Internet addiction group from the substance use and pathologic gambling groups that have been shown to be deficient in decision making on the Iowa test. Thus, students that fit these characteristics should be closely monitored to prevent Internet addiction.

Targeted Herceptin-dextran iron oxide nanoparticles for noninvasive imaging of HER2/neu receptors using MRI.

A novel magnetic resonance imaging (MRI) contrast agent containing Herceptin is reported. The surfaces of superparamagnetic iron oxide nanoparticles were modified with dextran and conjugated with Herceptin (Herceptin-nanoparticles) to improve their dispersion, magnetization, and targeting of the specific receptors on cells. From analytical results, we found that Herceptin-nanoparticles were well dispersed in solutions of various pH range, and had no hysteresis, high saturation magnetization (80 emu/g), and low cytotoxicity to a variety of cells. Notably, the magnetic resonance enhancements for the different breast cancer cell lines (BT-474, SKBR-3, MDA-MB-231, and MCF-7) are proportional to the HER2/neu expression level in vitro. When Herceptin-nanoparticles were administered to mice bearing breast tumor allograft by intravenous injection, the tumor site was detected in T (2)-weighted magnetic resonance images as a 45% enhancement drop, indicating a high level of accumulation of the contrast agent within the tumor sites. Therefore, targeting of cancer cells was observed by in vitro and in vivo MRI studies using Herceptin-nanoparticles contrast agent. In addition, Herceptin-nanoparticles enhancing the magnetic resonance signal intensity were sufficient to detect the cell lines with a low level of HER2/neu expression.