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Context: It is necessary to explore a minimally invasive, effective, and efficient treatment for those lung cancer patients who are poor candidates for surgery. Aim: This study aimed to investigate the application of microwave ablation (MWA) in the treatment of lung cancer. Settings and Design: A total of 43 patients with 44 pulmonary lesions were examined following identical procedures before being randomly divided into two groups. The experimental group consists of 17 patients with a total of 18 pulmonary lesions, while the control group consists of 26 patients with a total of 26 pulmonary lesions. Materials and Methods: The experimental group was treated using magnetic resonance imaging (MRI)-guided MWA while the control group was treated using computer tomography (CT)-guided MWA. A transverse relaxation time-turbo spin echo (T2-TSE) sequence was used for signal collection in the experimental group to determine puncture location and microwave needle position while T2-TSE, T1-turbo field echo, and diffusion-weighted MRI (DWI) sequences were used for timely efficacy evaluation. Whereas in the control group, CT axial scanning was performed to serve similar purposes. Statistical Analysis Used: A nonparametric Wilcoxon test, median (M [25%, 75%]). Results: All of the 44 lesions were successfully located on the first attempt. The mean time for scanning and locating lung lesions under MRI and CT guidance were 64.53 and 42.96 min, the mean times of positioning were 12 and 18 min, and the mean durations of MWA were 12.48 and 15.06 min, respectively. Conclusions: As a minimally invasive method for treating lung tumors, MRI-guided MWA requires fewer localization scans, a shorter MWA duration, no radiation, real-time observation of the curative effect, and it prevents overtreatment
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Objective To study the moisture transfer laws of Chaenomeles sinensis in different drying processes. Methods Using the non-destructive and non-invasive technique of low field-nuclear magnetic resonance (LF-NMR), the transverse relaxation time (T2) inversion spectrum of C. sinensis slice was monitored under different drying methods (hot air drying, drying after evaporation, segmental drying and drying in the shade) to analyze the changes of moisture migration. Results There were three different types water that were detected in C. sinensis (free water > bound water > immobilized water). The internal water distribution and water content changed during drying process. The moisture changes were similar in hot air drying, drying after steaming, and drying in shade, the total water gradually decreased, and the combining degree between moisture and non-water components enhanced. Steaming promoted the water loss rate of C. sinensis slice, the water loss rate was higher in drying after steaming than in hot air drying, and the difference was significant (P < 0.05). During the intermittent drying, the conversion of different states of water would occur in order to return to a relatively stable equilibrium. During the low temperature drying process, immobilized water content decreased and free water content increased. The low-temperature drying has less damage to the tissue, which is more conducive to the conversion of immobilized water into free water, and thus the water dissipated faster. During the early of drying, high temperature caused tissue structure damage, the bonding force between water and non-aqueous tissue would be strengthened because of the tissue shrinkage. Conclusion The three different types water content and peak area in T2 was positively correlated. The LF-NMR technique would provide useful guides for the investigation of water distribution and variation of C. sinensis, which will provide a theoretical basis for C. sinensis processing.
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Moisture status and content during the processing of Paeoniae Radix Alba were studied by nuclear magnetic resonance (NMR) and nuclear magnetic resonance imaging (MRI) to investigate the changes of transverse relaxation time (T ₂) and MRI images during boiling and drying processes of Paeoniae Radix Alba. The results showed that water in Paeoniae Radix Alba fresh products was major of free water, and in the boiling process, the content of free water increased whereas the content of bound water declined. At the end of boiling, content of free water reached over 90%. During the drying process, T ₂ moved to the left, and moisture mobility was reduced. The MRI image directly showed that moisture transfer was outside-in process for both increase and decrease. At the end of drying, remaining moisture was mainly present in inner layer of Paeoniae Radix Alba. Quality and appearance were affected by the change of moisture during processing process of medicinal herbs. NMR and MRI could provide direct reference evidence for its moisture changes, and the results of this study could provide direct references and technical support for optimization of processing process of root medicinal materials and evaluation of Chinese herbal pieces.
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PURPOSE: The purpose of this study was to investigate the effect of the number of measurement points on the calculation of transverse relaxation time (T2) with a focus on muscle T2. MATERIALS AND METHODS: This study assumed that muscle T2 was comprised of a single component. Two phantom types were measured, 1 each for long (“phantom”) and short T2 (“polyvinyl alcohol gel”). Right calf muscle T2 measurements were conducted in 9 healthy male volunteers using multiple-spin-echo magnetic resonance imaging. For phantoms and muscle (medial gastrocnemius), 5 regions of interests were selected. All region of interest values were expressed as the mean ± standard deviation. The T2 effective signal-ratio characteristics were used as an index to evaluate the magnetic resonance image quality for the calculation of T2 from T2-weighted images. The T2 accuracy was evaluated to determine the T2 reproducibility and the goodness-of-fit from the probability Q. RESULTS: For the phantom and polyvinyl alcohol gel, the standard deviation of the magnetic resonance image signal at each echo time was narrow and mono-exponential, which caused large variations in the muscle T2 decay curves. The T2 effective signal-ratio change varied with T2, with the greatest decreases apparent for a short T2. There were no significant differences in T2 reproducibility when > 3 measurement points were used. There were no significant differences in goodness-of-fit when > 6 measurement points were used. Although the measurement point evaluations were stable when > 3 measurement points were used, calculation of T2 using 4 measurement points had the highest accuracy according to the goodness-of-fit. Even if the number of measurement points was increased, there was little improvement in the probability Q. CONCLUSION: Four measurement points gave excellent reproducibility and goodness-of-fit when muscle T2 was considered mono-exponential.
Subject(s)
Humans , Male , Magnetic Resonance Imaging , Muscle, Skeletal , Polyvinyl Alcohol , Relaxation , VolunteersABSTRACT
The purpose of this study was to examine the recruitment state of synergistic muscles in the thigh muscles in leg press exercise with and without pre-fatigue method using transverse relaxation time (T2) on muscle functional magnetic resonance imaging (MRI). Nine healthy male subjects performed the following two types of exercise trials on separate days: 1) 5 sets of a leg press exercise with pre-fatigue method, which consisted of 3 sets of knee extension exercise (LP-pre), 2) 5 sets of a leg press exercise without pre-fatigue method (LP). Both exercises were performed at a load of 80% one-repetition maximum. Before and immediately after exercise, T2-weighted MR images of right-thigh were taken to calculate T2 values of twelve-thigh muscles. The T2 values for quadriceps femoris muscle and hamstrings in LP increased significantly after the exercise, except in the adductor magnus, adductor longus, gracilis, and sartorius. In contrast, the T2 values for all of the twelve-thigh muscles in LP-pre increased significantly after the exercise. Upon comparison between the two trials, the percentage changes in T2 value for the adductor magnus, adductor longus, and sartorius in LP-pre were found to be significantly greater than those in LP. These results suggest leg press exercise with pre-fatigue method may be effective to increase activity of synergistic muscles in thigh muscles during exercise.
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Magnetic seed treatment is one of the physical pre-sowing seed treatments to enhance the performance of crop plants. In our earlier experiment, we found significant increase in germination and vigour characteristics of maize (Zea mays L.) seeds subjected to magnetic fields. Among various combinations of magnetic field (MF) strength and duration, best results were obtained with MF of 100 mT for 2 h and 200 mT for 1 h exposure. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions. Thus, in the present study, changes in water uptake during imbibition and its distribution and activities of germinating enzymes during germination were investigated in maize seeds exposed to static magnetic fields of 100 and 200 mT for 2 and 1 h respectively by nuclear magnetic resonance (NMR) spectroscopy. The magnetically-exposed seed showed higher water uptake in phase II and III than unexposed seed. The longitudinal relaxation time T1 of seed water showed significantly higher values and hence greater molecular mobility of cellular water in magnetically-exposed seeds as compared to unexposed. Component analysis of T2 relaxation times revealed the early appearance of hydration water with least mobility and higher values of relaxation times of cytoplasmic bulk water and hydration water in magnetically-exposed over unexposed seeds. Activities of -amylase, dehydorgenase and protease during germination were higher in magnetically-exposed seeds as compared to unexposed. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions.