Brain structure variation and individual differences in theory of mind among older adults.

The theory of mind (ToM) is not substantially influenced by aging, suggesting the emergence of various compensatory mechanisms. To identify brain regions subserving ToM in older adults, we investigated the associations of individual differences in brain structure with performance on the Reading the Mind in the Eyes Test (RMET), a widely used measure of ToM, using voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS). In contrast to findings obtained from young adults, where multiple cortical regions are implicated in ToM, VBM analysis revealed a significant positive correlation between RMET score and gray matter (GM) volume only in the right middle temporal gyrus, a region implicated in social cognition. Alternatively, TBSS revealed significant positive correlations between RMET score and the fractional anisotropy (FA) values in widespread white matter (WM) tracts, including the bilateral uncinate fasciculus, a region previously linked to RMET performance in young adults. We speculate that individual differences in WM integrity are strong influences on ToM among older adults, whereas the impact of individual differences in GM volumes is relatively limited.

Examination of knee extensor and valgus moment arms of the patellar tendon in older individuals with and without knee osteoarthritis.

BACKGROUND: Joint moment arm is a major element that determines joint torque. This study aimed to investigate factors associated with knee extensor and valgus moment arms of the patellar tendon in older individuals with and without knee osteoarthritis. METHODS: Thirty-six participants with knee osteoarthritis (mean age, 78.1 ± 6.0 years) and 43 healthy controls (mean age, 73.0 ± 6.3 years) were analyzed. Magnetic resonance images (MRI) from the knee joint and thigh were acquired using a 3.0 T MRI scanner. The three-dimensional moment arm was defined as the distance between the contact point of the tibiofemoral joint and the patellar tendon line. The three-dimensional moment arm was decomposed into sagittal and coronal components, which were calculated as knee extensor and valgus moment arms, respectively. Quadriceps muscle volume, epicondylar width, bisect offset, Insall-Salvati ratio, and Kellgren-Lawrence grade were assessed. Multiple regression analyses were performed in the healthy control and knee osteoarthritis groups, with knee extensor and valgus moment arms as dependent variables. FINDINGS: Knee extensor moment arm was significantly associated with epicondylar width and the Insall-Salvati ratio in the healthy control group and with Kellgren-Lawrence grade, epicondylar width, and quadriceps muscle volume in the knee osteoarthritis group. Valgus knee moment arm was significantly associated with bisect offset in both the groups. INTERPRETATION: Knee size, osteoarthritis severity, and quadriceps muscle volume affect the knee extensor moment arm in knee osteoarthritis, whereas lateral patellar displacement affects the valgus knee moment arms in older individuals with and without knee osteoarthritis.

Novel image-guided marker aimed at organ-preserving therapies for prostate cancer.

OBJECTIVE: We developed fiducial imaging-guidance markers for the prostate with less imaging artifacts than currently commercially available markers. The aim of this study was to evaluate the imaging artifacts and potential usefulness and safety of these novel fiducial imaging markers in preclinical experiments. METHODS: We selected specific metal materials and a shape that can minimize artifacts in line with a license we obtained for a metal with a gold-platinum (Au-Pt) alloy composition that maximized artifact-free MRI images. Both phantom and canine prostate tests were conducted in order to evaluate the imaging artifacts for three imaging modalities, MRI, CT and ultrasound, and the risk of migration of the markers from the site of insertion to elsewhere, as well as crushing. RESULTS: The newly developed Au-Pt material had less imaging artifacts in the MRI, CT and ultrasound imaging modalities in comparison with current commercially available fiducial markers made from gold materials only. The Au-Pt markers had sufficient strength and durability and were considered to be potentially clinically useful and safe markers. CONCLUSION: The developed Au-Pt markers could be potential tools for accurate lesion-targeted, organ-preserving therapies such as lesion-targeted focal therapy and active surveillance in addition to conventional radiation therapies.

Reliability and validity of quantitative ultrasound for evaluating patellar alignment: A pilot study.

BACKGROUND: Patellar malalignment is a risk factor of patellofemoral pain. Evaluation of the patellar alignment have mostly used magnetic resonance imaging (MRI). Ultrasound (US) is a non-invasive instrument that can quickly evaluate patellar alignment. However, the method for evaluating patellar alignment via US has not been established. This study aimed to investigate the reliability and validity of evaluating patellar alignment via US. METHODS: The sixteen right knees were imaged via US and MRI. US images were obtained at two sites of the knee to measure US-tilt as the index of patellar tilt. Using a single US image, we measured US-lateral distance and US-angle as the index of patellar shift. All US images were obtained three times each by two observers to evaluate reliabilities. Lateral patellar angle (LPA), as the indicators of patellar tilt, and lateral patella distance (LPD) and bisect offset (BO), as the indicators of patellar shift, were measured via MRI. RESULTS: US measurements provided high intra- (within-day and between days) and interobserver reliabilities with exception of interobserver reliability of US-lateral distance. Pearson correlation coefficient indicated that US-tilt is significantly positively correlated with LPA (r = 0.79), and US-angle is significantly positively correlated with LPD (r = 0.71) and BO (r = 0.63). CONCLUSION: Evaluating patellar alignment via US showed high reliabilities. US-tilt and US-angle showed moderate to strong correlation with MRI indices of patellar tilt and shift via MRI, respectively. US methods are useful for evaluating accurate and objective indices of patellar alignment.

Transplantation of autologous bone marrow-derived mononuclear cells into cerebrospinal fluid in a canine model of spinal cord injury.

Introduction: Spinal cord injury (SCI) is associated with severe dysfunction of nervous tissue, and repair via the transplantation of bone marrow-derived mononuclear cells (BM-MNCs) into cerebrospinal fluid yields promising results. It is essential to understand the underlying mechanisms; therefore, this study aimed to evaluate the regenerative potential of autologous BM-MNC transplantation in a canine model of acute SCI. Methods: Six dogs were included in this study, and SCI was induced using an epidural balloon catheter between L2 and L3, particularly in the area of the anterior longitudinal ligament. BM-MNC transplantation was performed, and T2-weighted magnetic resonance imaging (MRI) was conducted at specific time points (i.e., immediately after inducing SCI and at 1, 2, and 4 weeks after inducing SCI); moreover, the expression of growth-associated protein 43 (GAP-43) was evaluated. Results: MRI revealed that the signal intensity reduced over time in both BM-MNC-treated and control groups. However, the BM-MNC-treated group exhibited a significantly faster reduction than the control group during the early stages of SCI induction (BM-MNC-treated group: 4.82 ± 0.135 cm [day 0], 1.71 ± 0.134 cm [1 week], 1.37 ± 0.036 cm [2 weeks], 1.21 cm [4 weeks]; control group: 4.96 ± 0.211 cm [day 0], 2.49 ± 0.570 cm [1 week], 1.56 ± 0.045 cm [2 weeks], 1.32 cm [4 weeks]). During the early stages of treatment, GAP-43 was significantly expressed at the proximal end of the injured spinal cord in the BM-MSC-treated group, whereas it was scarcely expressed in the control group. Conclusions: In SCI, transplanted BM-MNCs can activate the expression of GAP-43, which is involved in axonal elongation (an important process in spinal cord regeneration). Thus, cell therapy with BM-MNCs can provide favorable outcomes in terms of better regenerative capabilities compared with other therapies.

Association of Regional Muscle Thickness and Echo Intensity with Muscle Volume, Intramuscular Adipose Tissue, and Strength of the Quadriceps Femoris.

Purpose: This study aimed to investigate the association of muscle thickness (MT) and echo intensity (EI) obtained at different regions along the muscle length with muscle volume (MV), intramuscular adipose tissue (IntraMAT), and muscle strength of the quadriceps femoris (QF). Patients and Methods: A total of 135 community-dwelling adults (64 men and 71 women) participated in the study. Ultrasound scanning of the rectus femoris (RF) and vastus intermedius (VI) was performed at three locations (from mid- to distal thigh). The MT of the RF and VI and EI of the RF were measured. MRI-derived MV, IntraMAT, and muscle strength of the QF were measured. Results: The correlation between RF-MT and RF-MV weakened as scanning approached the distal thigh, and the difference between the coefficients for the scanning locations was significant for women. However, the correlation of VI-MT with VI-MV and that of the combined MT of RF and VI with the MV of the whole QF and muscle strength were comparable among the scanning locations for both sexes. The correlation of RF-EI with the IntraMAT of the RF and the whole QF and muscle strength was also comparable among the scanning locations for both sexes. Conclusion: The results of this study suggest that ultrasound measurements at the distal thigh can predict MV, IntraMAT, and muscle strength of the QF to the same degree as those at the mid-thigh.

Sitting vs. supine ultrasound measurements of the vastus medialis: correlations with MRI measurements and age considerations.

BACKGROUND: Muscle thickness (MT) and echo intensity (EI) measurements are ultrasound alternatives to magnetic resonance imaging (MRI) for evaluating muscle quantity and quality. The vastus medialis (VM) is a clinically important muscle, and assessment methods that most accurately reflect its quantity and quality are required. This study aimed to examine the correlation between MT and EI measured in the supine and sitting postures with corresponding MRI-measured muscle quantity and quality indices. METHODS: In total, 134 adults (91 older and 43 young) participated in this study. Ultrasound images of the VM were acquired in the supine and sitting postures, and MT and EI were measured. The cross-sectional area (CSA), muscle volume (MV), and intramuscular adipose tissue (intraMAT) of the VM were evaluated from MRI images using T1-weighted and Dixon methods. Pearson's coefficients were used to quantify the correlation strength amongst pairs of dependent variables. Meng's test was used to test for correlation coefficient differences between the two measurement postures (supine and sitting). RESULTS: The correlation coefficients amongst MT, CSA, and MV were significantly higher in the sitting posture than in the supine posture. EI measured in the supine and sitting postures correlated significantly with intraMAT, and in young individuals, these correlation coefficients were significantly higher in the sitting posture than in the supine posture. CONCLUSIONS: These findings suggest that assessment of VM muscle quantity in the sitting posture is superior for young and older individuals, and assessment of VM muscle quality in the sitting posture is most effective in younger individuals.

A higher intramuscular fat in vastus medialis is associated with functional disabilities and symptoms in early stage of knee osteoarthritis: a case-control study.

BACKGROUND: The characteristics of muscle degeneration in individual quadriceps in early knee osteoarthritis (OA) and the association of muscle quantity and quality on knee dysfunction remain unclear. This study aimed to clarify the characteristics of muscle degeneration in individual quadriceps muscles in early knee OA and elucidate the association of muscle volume and intramuscular adipose tissue (intraMAT) with knee dysfunction, including functional disabilities, symptoms, and joint morphology. METHODS: Fifty participants were categorized into early knee OA and healthy control groups. 3.0 T magnetic resonance imaging (MRI) using T1-weighted and Dixon methods and 3D SPACE in the thigh muscle and knee joint regions was performed. Quadriceps muscle volume, intraMAT, and whole-organ MRI score (WORMS) were assessed. The Knee Society Score (KSS) was used to evaluate functional disabilities and knee symptoms. Univariate analysis of variance was conducted with covariates to clarify the differences in muscle volume and intraMAT between the two groups. Multiple linear regression analyses were performed using the KSS function and symptom subcategories and WORMS as dependent variables and muscle volume, intraMAT, and the presence of early knee OA as independent variables, such as potential confounders. RESULTS: The quadriceps intraMAT, especially in the vastus medialis (VM), was significantly higher in patients with early knee OA than in healthy controls. The VM intraMAT, not muscle volume, was significantly associated with KSS function [B = - 3.47; 95% confidence interval [CI], - 5.24 to - 1.71; p < 0.001] and symptom scores [B = - 0.63; 95% CI, - 1.09 to - 0.17; p = 0.008], but not with WORMS. CONCLUSION: These findings suggest that higher VM intraMAT is characteristic of quadriceps muscle degeneration in early knee OA and its increase is associated with functional disabilities and symptoms.

Cortical and subcortical grey matter correlates of psychopathic traits in a Japanese community sample of young adults: sex and configurations of factors' level matter!

While neuroimaging research has examined the structural brain correlates of psychopathy predominantly in clinical/forensic male samples from western countries, much less is known about those correlates in non-western community samples. Here, structural magnetic resonance imaging data were analyzed using voxel- and surface-based morphometry to investigate the neuroanatomical correlates of psychopathic traits in a mixed-sex sample of 97 well-functioning Japanese adults (45 males, 21-39 years; M = 27, SD = 5.3). Psychopathic traits were assessed using the Self-Report Psychopathy Scale (SRP-SF; 4th Edition). Multiple regression analysis showed greater Factor 1 scores were associated with higher gyrification in the lingual gyrus, and gray matter volume in the anterior cingulate cortex and amygdala/hippocampus border. Total psychopathy and Factor 1 scores interacted with sex to, respectively, predict cortical thickness in the precuneus and gyrification in the superior temporal gyrus. Finally, Factor 1 and Factor 2 traits interacted to predict gyrification in the posterior cingulate cortex. These preliminary data suggest that, while there may be commonalities in the loci of structural brain correlates of psychopathic traits in clinical/forensic and community samples, the nature of that association might be different (i.e. positive) and may vary according to sex and configurations of factors' level.

Enhanced mirror neuron network activity and effective connectivity during live interaction among female subjects.

Facial expressions are indispensable in daily human communication. Previous neuroimaging studies investigating facial expression processing have presented pre-recorded stimuli and lacked live face-to-face interaction. Our paradigm alternated between presentations of real-time model performance and pre-recorded videos of dynamic facial expressions to participants. Simultaneous functional magnetic resonance imaging (fMRI) and facial electromyography activity recordings, as well as post-scan valence and arousal ratings were acquired from 44 female participants. Live facial expressions enhanced the subjective valence and arousal ratings as well as facial muscular responses. Live performances showed greater engagement of the right posterior superior temporal sulcus (pSTS), right inferior frontal gyrus (IFG), right amygdala and right fusiform gyrus, and modulated the effective connectivity within the right mirror neuron system (IFG, pSTS, and right inferior parietal lobule). A support vector machine algorithm could classify multivoxel activation patterns in brain regions involved in dynamic facial expression processing in the mentalizing networks (anterior and posterior cingulate cortex). These results indicate that live social interaction modulates the activity and connectivity of the right mirror neuron system and enhances spontaneous mimicry, further facilitating emotional contagion.

Influence of ultrasound focus depth on the association between echo intensity and intramuscular adipose tissue.

INTRODUCTION/AIMS: Attenuation of the ultrasound (US) wave is a serious limitation of echo intensity (EI) on B-mode US. The aim of this study was to determine whether the focus depth of US images influences the depth-dependent attenuation of EI and the relationship between EI and intramuscular adipose tissues (IntraMAT). METHODS: The rectus femoris (RF) and vastus intermedius (VI) of the right thigh were studied in 135 adults (92 older, 43 younger). The EI on US images was measured at three focus depth conditions: top of the image, center of the RF, and center of the VI. The depth of the region of interest (ROI) was measured. IntraMAT was calculated using water and fat images based on the two-point Dixon technique with a 3.0-T magnetic resonance imaging scanner. RESULTS: The correlation between EI and IntraMAT was stronger in the focus RF and VI conditions than in the focus top condition and stronger for RF than for VI. The depth of the ROI influenced the IntraMAT-adjusted residual EI more in the focus top condition than in the focus RF and VI conditions, and influenced VI more strongly than it did RF. DISCUSSION: By mitigating EI attenuation, EI with a focus depth adjusted to the ROI reflected IntraMAT more accurately than that without adjustment. However, it may not completely prevent the potential influence of depth-dependent attenuation of EI, especially for deeper muscles such as the VI.

Age- and sex-related differences of muscle cross-sectional area in iliocapsularis: a cross-sectional study.

BACKGROUND: This study aimed to determine in how many individuals the iliocapsularis muscle (IC) could be identified on magnetic resonance imaging (MRI) and whether age and sex are associated with the cross-sectional area (CSA) of the IC. METHODS: Thirty-seven healthy younger adults and 40 healthy older adults were assigned to four groups: 1) 20 younger men; 2) 17 younger women; 3) 20 older men; and 4) 20 older women. The CSAs of the IC, IP, the rectus femoris (RF) and the quadriceps (QUAD) were quantified on an axial MRI. RESULTS: The number of individuals with the identified IC was n = 17 (85.0%) of 20 younger men, n = 15 (88.2%) of 17 younger women, n = 18 (90.0%) of 20 older men, and 19 (95.0%) of 20 older women. Our results showed the main effect of sex, but not age, in the CSA of the IC. The men-groups had larger CSA of the IC than the women-groups; however, no difference in CSA of the IC was found between the younger and older groups. Meanwhile, the main effects of age and sex were found for the IP, RF, and QUAD; thus, younger or men groups have larger CSAs of the three muscles than the older or women groups. The IC muscle can be discriminated in 85% - 95% of healthy individuals. CONCLUSION: Although sex and age are associated with the CSA of lower-limb muscles other than the IC, only sex is associated with the CSA of the IC.

Dual-phase Au-Pt alloys free from magnetic susceptibility artifacts in magnetic resonance imaging.

PURPOSE: Magnetic resonance imaging (MRI) devices are frequently used in image-based diagnosis. In the case of large artifacts, which are generated in magnetic resonance (MR) images when magnetic materials, such as metals, are present in the body, these devices are less useful. This study aimed to develop a dual-phase Au-Pt alloy that does not generate artifacts in MR images and has high workability to prepare medical devices. MATERIALS AND METHODS: A processing method to produce a dual-phase Au-Pt alloy was established, and the magnetic susceptibility and artifacts of different alloy compositions were determined using a SQUID (superconducting quantum interference device) flux meter and a 1.5 T-MRI system. The crystallographic phases of the prepared alloy samples were identified using X-ray diffraction. Sample cross-sections were observed using a metallurgical microscope. Furthermore, a thinning test was conducted to examine alloy workability. RESULTS: Dual-phase Au-Pt alloys Au70Pt30 and Au67Pt33-the former heat-treated at 800 and 850 °C and the latter heat-treated at 900 °C-generated minimal artifacts when imaged in a 1.5 T-MRI system. Their volume magnetic susceptibility increased as the heat-treatment temperature decreased. The alloy surfaces were observed to be uniform. Moreover, the workability of the dual-phase alloy was considerably better than that of the single-phase alloy. CONCLUSION: Volume magnetic susceptibility could be controlled by changing the composition and processing temperature of the Au-Pt alloys. Dual-phase Au-Pt alloys those do not generate magnetic susceptibility artifacts in MRI images and have good workability could be prepared. The alloys are expected to be used in the preparation of various implantable medical devices.

Impact of Early-Commenced and Continued Sports Training on the Precuneus in Older Athletes.

Intervention studies on sedentary older adults have demonstrated that commencing physical exercise at an older age has a positive effect on brain structure. Although this suggests that older athletes with lifelong sports training have larger gray matter volume (GMV) in some brain regions compared to age-matched non-athletes, evidence in the literature is scarce. Moreover, it remains unclear whether a larger GMV is associated with training intensity or period of training in life. To address these gaps in the literature, we compared regional brain GMV between 24 older athletes (mean age, 71.4 years; age at the commencement of sports training, 31.2 years, continuous sports training, 40.0 years; current training time, 7.9 h/week) and 24 age-matched non-athletes (mean age, 71.0 years). The period of sports training and the current training time of the athletes were assessed. Both groups were evaluated for physical activity intensity as well as cognitive and motor performance. Although no group differences were noted in cognitive and motor performance, athletes reported higher physical activity intensity than non-athletes. Whole-brain structural analysis revealed a significantly larger GMV in several brain regions in athletes. Notably, the GMV of the precuneus in athletes was positively correlated with earlier commencement of sports training and training duration but was negatively correlated with current training time. Our findings demonstrate that early-commenced and continued sports training predicts structural maintenance of the precuneus in old age. Our results also suggest that excessive training time in old age may have a negative impact on the GMV of the precuneus; thereby delineating how the precuneus is associated with lifelong sports training in older athletes.

Estimating thigh skeletal muscle volume using multi-frequency segmental-bioelectrical impedance analysis.

BACKGROUND: The primary aim of this study was to investigate whether using the extracellular water/intracellular water (ECW/ICW) index and phase angle combined with segmental-bioimpedance analysis (BIA) improved the model fitting of skeletal muscle volume (SMV) estimation. The secondary aim was to compare the accuracy of segmental-BIA with that of ultrasound for estimating the quadriceps SMV measured with MRI. METHODS: Seventeen young men (mean age, 23.8 ± 3.3 years) participated in the study. The T-1 weighted images of thigh muscles were obtained using a 1.5 T magnetic resonance imaging (MRI) scanner. Thigh and quadriceps SMVs were calculated as the sum of the products of anatomical cross-sectional area and slice thickness of 6 mm across all slices. Segmental-BIA was applied to the thigh region, and data on the 50-kHz bioelectrical impedance (BI) index, ICW index, ECW/ICW index, and phase angle were obtained. The muscle thickness index was calculated as the product of the mid-thigh muscle thickness, determined using ultrasound, and thigh length. The standard error of estimate (SEE) of the regression equation was calculated to determine the model fitting of SMV estimation and converted to %SEE by dividing the SEE values by the mean SMV. RESULTS: Multiple regression analysis indicated that the combination of 50-kHz BI and the ECW/ICW index or phase angle was a significant predictor when estimating thigh SMV (SEE = 7.9 and 8.1%, respectively), but were lower than the simple linear regression (SEE = 9.4%). The ICW index alone improved the model fitting for the estimation equation (SEE = 7.6%). The model fitting of the quadriceps SMV with the 50-kHz BI or ICW index was similar to that with the skeletal muscle thickness index measured using ultrasound (SEE = 10.8, 9.6 and 9.7%, respectively). CONCLUSIONS: Combining the traditionally used 50-kHz BI index with the ECW/ICW index and phase angle can improve the model fitting of estimated SMV measured with MRI. We also showed that the model suitability of SMV estimation using segmental-BIA was equivalent to that on using ultrasound. These data indicate that segmental-BIA may be a useful and cost-effective alternative to the gold standard MRI for estimating SMV.

Neural Representations of Death in the Cortical Midline Structures Promote Temporal Discounting.

Death is an important reminder that our lives are finite. Although some studies have shown that thinking about one's own death increases temporal discounting (i.e., the devaluing of future rewards), the underlying neural mechanisms are still unknown. In a functional magnetic resonance imaging experiment, we compared the neural and behavioral processes of temporal discounting across four conditions involving distinct types of future thinking (death related, negative, neutral, and positive). Replicating prior research, the behavioral evidence showed that temporal discounting increased when thinking about one's own future death. Multivoxel pattern analysis showed that death-related future thinking was decoded in default mode regions, including the inferior parietal lobule, precuneus, and medial prefrontal cortex (MPFC). When future thinking was death related (vs. negative), increased temporal discounting was associated with a higher decoding accuracy in the precuneus and MPFC. The present findings suggest that death-related neural representations are distributed across default mode regions, and neural populations in the cortical midline structures play a crucial role in the integration of one's own death into economic decision-making.

Prefrontal Plasticity after a 3-Month Exercise Intervention in Older Adults Relates to Enhanced Cognitive Performance.

This study examined exercise intervention effects on older adults' brain structures and function. Brain data were analyzed from 47 healthy adults between 61 and 82 years of age who, in a previous study, showed cognitive improvement following a 3-month intervention. The participants were assigned to a motor exercise intervention group (n = 24), performing exercise training programs for a 12-week period, or a waiting control group (n = 23), abstaining from any exercise program. Structural analysis of the frontal cortex and hippocampus revealed increased gray matter volume and/or thickness in several prefrontal areas in the intervention group and reduced hippocampal gray matter volume in the control group. Importantly, the volume increase in the middle frontal sulcus in the intervention group was associated with a general cognitive improvement after the intervention. Functional analysis showed that the prefrontal functional connectivity during a working memory task differently changed in response to the intervention or waiting in the two groups. The functional connectivity decreased in the intervention group, whereas the corresponding connectivity increased in the control group, which was associated with maintaining cognitive performance. The current longitudinal findings indicate that short-term exercise intervention can induce prefrontal plasticity associated with cognitive performance in older adults.

Brain activity associated with the rubber foot illusion.

The internal representation of the body is constantly updated by sensory information based on interactions with the environment. The internal representation of the hand can be experimentally manipulated with the rubber hand illusion (RHI) paradigm. Brain activity during the RHI provides insight into the neural mechanisms underpinning the reconstruction of the internal representation of the hand. Recently, the RHI paradigm has been employed for the lower limb, revealing that the illusion is also induced in the lower limb (rubber foot illusion; RFI). However, the neural correlates of the RFI remain unknown. We used functional magnetic resonance imaging (fMRI) to examine brain activity during the RFI. Forty-four healthy volunteers participated in the fMRI experiment. Significant increases in activation were observed in the bilateral medial and middle frontal gyri, left supplemental motor area, bilateral inferior parietal lobuli, precunei, calcarine cortices, and cerebellar hemispheres; and in the vermis and bilateral thalami during the right RFI. During the left RFI, significant increases in activation were observed in the bilateral medial, middle, and superior frontal gyri; left inferior frontal gyrus and supplemental motor area, bilateral inferior parietal lobuli and middle temporal gyri, and in the left cerebellar hemisphere, vermis, and bilateral thalami. Conjunction analysis revealed that the prefrontal cortex including the bilateral medial and middle frontal gyri, parietal cortex including the bilateral inferior parietal lobuli, and cerebellum including the bilateral cerebellar hemispheres and vermis were conjointly activated during the right and left RFIs. The distribution of co-activated brain areas during the RFI was similar to the previously reported distribution of brain areas activated during the RHI. Co-activation of these brain areas may be associated with the reconstruction of the internal representation of the body. The fact that these areas are activated both in the RFI and RHI will have implications for the treatment of patients with disturbed internal bodily representation.