ObjectivesTo compare the efficacy of two quantitative methods for discrimination between benign and malignant focal liver lesions (FLLs): apparent diffusion coefficient (ADC) values and T2 relaxation times.MethodsSeventy-three patients with 215 confirmed FLLs (115 benign, 100 malignant) underwent 1.5-T MRI with respiratory-triggered single-shot SE DWI (b = 50, 400, 800) and dual-echo T2TSE (TR = 3,000 ms; TE1 = 84 ms; TE2 = 228 ms). ADC values and T2 relaxation times of FLLs were calculated. Sensitivity, specificity and accuracy of both techniques in diagnosing malignancy were assessed.ResultsThe mean ADC value of malignant tumours (1.07 × 10−3 mm2/s) was significantly lower (P < 0.05) than that of benign lesions (1.86 × 10−3 mm2/s ); however, with the use of the optimal cut-off value of 1.25 × 10−3 mm2/s, 20 false positive (FP) and 20 false negative (FN) diagnoses of malignancy were noted, generating 79 % sensitivity, 82.6 % specificity and 80.9 % accuracy. The mean T2 relaxation time of malignant tumours (64.4 ms) was significantly lower (P < 0.05) than that of benign lesions (476.1 ms). At the threshold of 107 ms 22 FP and 1 FN diagnoses were noted; the sensitivity was 99 %, specificity 80.9 % and accuracy 89.3 %.ConclusionsQuantitative analysis of T2 relaxation times yielded significantly higher sensitivity and accuracy in diagnosing malignant liver tumour than ADC values.Key Points• Diffusion-weighted magnetic resonance imaging is increasingly used for liver lesions.• But ADC values demonstrated only moderate accuracy for differentiation of liver lesions.• T2 relaxation times yielded higher accuracy in diagnosing malignant liver tumours.• Both ADC and T2 values overlapped between focal nodular hyperplasia and malignant lesions.• Nevertheless T2 liver mapping could be valuable for evaluating focal liver lesions.
Deception has always been a part of human communication as it helps to promote self-presentation. Although both men and women are equally prone to try to manage their appearance, their strategies, motivation and eagerness may be different. Here, we asked if lying could be influenced by gender on both the behavioral and neural levels. To test whether the hypothesized gender differences in brain activity related to deceptive responses were caused by differential socialization in men and women, we administered the Gender Identity Inventory probing the participants’ subjective social sex role. In an fMRI session, participants were instructed either to lie or to tell the truth while answering a questionnaire focusing on general and personal information. Only for personal information, we found differences in neural responses during instructed deception in men and women. The women vs. men direct contrast revealed no significant differences in areas of activation, but men showed higher BOLD signal compared to women in the left middle frontal gyrus (MFG). Moreover, this effect remained unchanged when self-reported psychological gender was controlled for. Thus, our study showed that gender differences in the neural processes engaged during falsifying personal information might be independent from socialization.
The differentiation of hemangioma from other hepatic neoplasms using MRI usually relies on the evaluation of heavily T2-weighted images. The aim of this study was to assess the value of T2-relaxation times calculated from moderately T2-weighted turbo spin-echo (TSE) sequence in characterization of focal hepatic lesions, including hepatic malignancies, focal nodular hyperplasia (FNH), hemangioma, and cyst. Fifty-two patients with 114 proven lesions (61 malignant masses, 6 focal nodular hyperplasias, 28 hemangiomas, 19 cystic lesions) were examined on 1.5-T system using a double-echo TSE sequence (TR=1800 ms; TE(eff) 1=40 ms; TE(eff) 2=120 ms). Signal intensities (SI) of the liver as well as SI of all lesions were measured, and then the T2-relaxation times were calculated. The mean T2 time for the liver was 54 ms (+/-8 ms), for FNH 66 ms (+/-7 ms), for malignant hepatic lesions 85 ms (+/-17 ms), for hemangiomas 155 ms (+/-35 ms), and for cystic lesions 583 ms (+/-369) ms. Most malignant hepatic lesions were best differentiated between the thresholds of 67 and 116 ms, generating a sensitivity of 90% and a specificity of 94%. There were six false-negative diagnoses of malignant tumor and three false-positive cases (two hemangiomas and one FNH). Calculation of the T2-relaxation times obtained from the double-echo TSE sequence with moderate T2-weighting allowed differentiation between malignant and benign hepatic lesions with high sensitivity and specificity.
The aim of this study was to determine the effectiveness of brain proton magnetic resonance spectroscopy ((1)H-MRS) for monitoring therapy in Wilson's disease (WD) patients. Voxels were located in the globus pallidus (right, left). We followed 17 newly diagnosed WD cases for 1-year period. During this observation period, 6 neurological and 9 hepatic patients improved, while 2 neurological patients deteriorated. The pretreatment (1)H-MRS analysis showed a statistically significant lower level of mI/Cr, NAA/Cr, and higher Lip/Cr in all WD patients with improvement compared with controls. In patients with hepatic signs, a statistically significant increase of mI/Cr and Glx/Cr was observed in the second (1 year posttreatment) (1)H-MRS. In patients with neurological improvement after treatment in the follow-up (1)H-MRS, a statistically significant increase of NAA/Cr was noted. During neurological deterioration, a decrease of Glx/Cr and NAA/Cr was seen, in contrast to another neurologically impaired patient with liver failure exacerbation, where a decrease of mI/Cr and increase of Glx/Cr was observed. The alternations of NAA/Cr ratio in neurologically impaired patients and mI/Cr and Glx/Cr in patients with liver failure could be a sensitive marker of the clinical recovery and deterioration in those WD patients. (1)H-MRS is a technique that can be used for accurate monitoring of treatment efficacy in WD patients.
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