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Repetitive transcranial magnetic stimulation (rTMS) to the left dorsolateral prefrontal cortex (DLPFC) is an established treatment for medication-resistant depression. Several targeting methods for the left DLPFC have been proposed including identification with resting-state functional magnetic resonance imaging (rs-fMRI) neuronavigation, stimulus coordinates based on structural MRI, or electroencephalography (EEG) F3 site by Beam F3 method. To date, neuroanatomical and neurofunctional differences among those approaches have not been investigated on healthy subjects, which are structurally and functionally unaffected by psychiatric disorders. This study aimed to compare the mean location, its dispersion, and its functional connectivity with the subgenual cingulate cortex (SGC), which is known to be associated with the therapeutic outcome in depression, of various approaches to target the DLPFC in healthy subjects. Fifty-seven healthy subjects underwent MRI scans to identify the stimulation site based on their resting-state functional connectivity and were measured their head size for targeting with Beam F3 method. In addition, we included two fixed stimulus coordinates over the DLPFC in the analysis, as recommended in previous studies. From the results, the rs-fMRI method had, as expected, more dispersed target sites across subjects and the greatest anticorrelation with the SGC, reflecting the known fact that personalized neuronavigation yields the greatest antidepressant effect. In contrast, the targets located by the other methods were relatively close together with less dispersion, and did not differ in anticorrelation with the SGC, implying their limitation of the therapeutic efficacy and possible interchangeability of them., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Research suggests structural and connectivity abnormalities in patients with treatment-resistant schizophrenia (TRS) compared to first-line responders and healthy-controls. However, measures of these abnormalities are often influenced by external factors like nicotine and antipsychotics, limiting their clinical utility. Intrinsic-cortical-curvature (ICC) presents a millimetre-scale measure of brain gyrification, highly sensitive to schizophrenia differences, and associated with TRS-like traits in early stages of the disorder. Despite this evidence, ICC in TRS remains unexplored. This study investigates ICC as a marker for treatment resistance in TRS, alongside structural indices for comparison., Methods: We assessed ICC in anterior cingulate, dorsolateral prefrontal, temporal, and parietal cortices of 38 first-line responders, 30 clozapine-resistant TRS, 37 clozapine-responsive TRS, and 52 healthy-controls. For comparative purposes, Fold and Curvature indices were also analyzed., Results: Adjusting for age, sex, nicotine-use, and chlorpromazine equivalence, principal findings indicate ICC elevations in the left hemisphere dorsolateral prefrontal (p < 0.001, η2partial = 0.142) and temporal cortices (LH p = 0.007, η2partial = 0.060; RH p = 0.011, η2partial = 0.076) of both TRS groups, and left anterior cingulate cortex of clozapine-resistant TRS (p = 0.026, η2partial = 0.065), compared to healthy-controls. Elevations that correlated with reduced cognition (p = 0.001) and negative symptomology (p < 0.034) in clozapine-resistant TRS. Fold and Curvature indices only detected group differences in the right parietal cortex, showing interactions with age, sex, and nicotine use. ICC showed interactions with age., Conclusion: ICC elevations were found among patients with TRS, and correlated with symptom severity. ICCs relative independence from sex, nicotine-use, and antipsychotics, may support ICC's potential as a viable marker for TRS, though age interactions should be considered., Competing Interests: Declaration of competing interest There are no funding, employment or personal financial interests of any kind that would undermine the objectivity, integrity or perceived value of the submitted publication. In order of authorship listing: Edgardo Torres-Carmona declaration of interest: none. Fumihiko Ueno declaration of interest: none. Yusuke Iwata declaration of interest: none. Shinichiro Nakajima declaration of interest: none. Jianmeng Song declaration of interest: none. Wanna Mar declaration of interest: none. Ali Abdolizadeh declaration of interest: none. Sri Mahavir Agarwal declaration of interest: none. Vincenzo de Luca declaration of interest: none. Gary Remington has received advisory board support from HLS Therapeutics and consultant fees from Mitsubishi Tanabe Pharma Corporation. Philip Gerretsen declaration of interest: none. Ariel Graff-Guerrero declaration of interest: none., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: The rarity of IDH2 mutations in supratentorial gliomas has led to gaps in understanding their radiological characteristics, potentially resulting in misdiagnosis based solely on negative IDH1 immunohistochemical staining. We aimed to investigate the clinical and imaging characteristics of IDH2-mutant gliomas., Methods: We analyzed imaging data from adult patients with pathologically confirmed diffuse lower-grade gliomas and known IDH1/2 alteration and 1p/19q codeletion statuses obtained from the records of our institute (January 2011 to August 2022, Cohort 1) and The Cancer Imaging Archive (TCIA, Cohort 2). Two radiologists evaluated clinical information and radiological findings using standardized methods. Furthermore, we compared the data for IDH2-mutant and IDH-wildtype gliomas. Multivariate logistic regression was used to identify the predictors of IDH2 mutation status, and receiver operating characteristic curve analysis was employed to assess the predictive performance of the model., Results: Of the 20 IDH2-mutant supratentorial gliomas, 95% were in the frontal lobes, with 75% classified as oligodendrogliomas. Age and the T2-FLAIR discordance were independent predictors of IDH2 mutations. Receiver operating characteristic curve analysis for the model using age and T2-FLAIR discordance demonstrated a strong potential for discriminating between IDH2-mutant and IDH-wildtype gliomas, with an area under the curve of 0.96 (95% CI, 0.91-0.98, P = .02)., Conclusion: A high frequency of oligodendrogliomas with 1p/19q codeletion was observed in IDH2-mutated gliomas. Younger age and the presence of the T2-FLAIR discordance were associated with IDH2 mutations and these findings may help with precise diagnoses and treatment decisions in clinical practice., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Quantitative susceptibility mapping (QSM) is a unique technique for providing quantitative information on tissue magnetic susceptibility using phase image data. QSM can provide valuable information regarding physiological and pathological processes such as iron deposition, hemorrhage, calcification, and myelin. QSM has been considered for use as an imaging biomarker to investigate physiological status and pathological changes. Although various studies have investigated the clinical applications of QSM, particularly regarding the use of QSM in clinical practice, have not been examined well. This review provides on an overview of the basics of QSM and its clinical applications in neuroradiology. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2., (© 2023 International Society for Magnetic Resonance in Medicine.)

Objectives: To evaluate susceptibility values associated with iron accumulation in the deep gray matter during postnatal development and to compare magnetic susceptibility between patients with normal and delayed development., Methods: Patients with postmenstrual age (PMA) ≤ 1000 days underwent MR scans between August 2015 and April 2020 at our hospital. Quantitative susceptibility mapping (QSM) was performed, and magnetic susceptibility was measured using three-dimensional volumes of interest (VOIs) for the caudate nucleus (CN), globus pallidus (GP), putamen (PT), and ventrolateral thalamic nucleus (VL). Cross-sectional analysis was performed for 99 patients with normal development and 39 patients with delayed development. Longitudinal analysis was also performed to interpret changes over time in 13 patients with normal development. Correlations between magnetic susceptibility in VOIs and PMA or chronological age (CA) were assessed., Results: Susceptibility values for CN, GP, PT, and VL showed positive moderate correlations with both PMA (ρ = 0.45, 0.69, 0.62, and 0.33, respectively) and CA (ρ = 0.53, 0.69, 0.66, and 0.39, respectively). The slope of the correlation between susceptibility values and age was highest in the GP among the four gray matter areas. Susceptibility values for the CN, GP, PT, and VL were higher with normal development than with delayed development at early postnatal age, although a significant difference was only observed for the CN. Susceptibility values also increased with age in the longitudinal analysis., Conclusions: Magnetic susceptibility values in deep gray matter increased with age ≤ 1000 days. The normal development group showed higher susceptibility values than the delayed development group at early postnatal age (PMA ≤ 285 days)., Key Points: • Magnetic susceptibilities in deep gray matter nuclei increased with age (postmenstrual age ≤ 1000 days) in a large number of pediatric patients. • The normal development group showed higher susceptibility values than the delayed development group in the basal ganglia and ventrolateral thalamic nucleus at early postnatal age (PMA ≤ 285 days)., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To assess the accuracy, repeatability, and reproducibility of T 1 and T 2 relaxation time measurements by three-dimensional magnetic resonance fingerprinting (3D MRF) using various dictionary resolutions., Methods: The ISMRM/NIST phantom was scanned daily for 10 days in two 3 T MR scanners using a 3D MRF sequence reconstructed using four dictionaries with varying step sizes and one dictionary with wider ranges. Thirty-nine healthy volunteers were enrolled: 20 subjects underwent whole-brain MRF scans in both scanners and the rest in one scanner. ROI/VOI analyses were performed on phantom and brain MRF maps. Accuracy, repeatability, and reproducibility metrics were calculated., Results: In the phantom study, all dictionaries showed high T 1 linearity to the reference values (R 2 > 0.99), repeatability (CV < 3%), and reproducibility (CV < 3%) with lower linearity (R 2 > 0.98), repeatability (CV < 6%), and reproducibility (CV ≤ 4%) for T 2 measurement. The volunteer study demonstrated high T 1 reproducibility of within-subject CV (wCV) < 4% by all dictionaries with the same ranges, both in the brain parenchyma and CSF. Yet, reproducibility was moderate for T 2 measurement (wCV < 8%). In CSF measurement, dictionaries with a smaller range showed a seemingly better reproducibility (T 1 , wCV 3%; T 2 , wCV 8%) than the much wider range dictionary (T 1 , wCV 5%; T 2 , wCV 13%). Truncated CSF relaxometry values were evident in smaller range dictionaries., Conclusions: The accuracy, repeatability, and reproducibility of 3D MRF across various dictionary resolutions were high for T 1 and moderate for T 2 measurements. A lower-resolution dictionary with a well-defined range may be adequate, thus significantly reducing the computational load., Key Points: • A lower-resolution dictionary with a well-defined range may be sufficient for 3D MRF reconstruction. • CSF relaxation times might be underestimated due to truncation by the upper dictionary range. • Dictionary with a higher upper range might be advisable, especially for CSF evaluation and elderly subjects whose perivascular spaces are more prominent., (© 2022. The Author(s).)

Vessel wall MR imaging (VW-MRI) has been introduced into clinical practice and applied to a variety of diseases, and its usefulness has been reported. High-resolution VW-MRI is essential in the diagnostic workup and provides more information than other routine MR imaging protocols. VW-MRI is useful in assessing lesion location, morphology, and severity. Additional information, such as vessel wall enhancement, which is useful in the differential diagnosis of atherosclerotic disease and vasculitis could be assessed by this special imaging technique. This review describes the VW-MRI technique and its clinical applications in arterial disease, venous disease, vasculitis, and leptomeningeal disease., (© 2022. Italian Society of Medical Radiology.)

Alpha-methyl-para-tyrosine (AMPT), a competitive inhibitor of tyrosine hydroxylase, can be used to deplete endogenous dopamine in humans. We examined how AMPT-induced dopamine depletion alters resting-state functional connectivity of the basal ganglia, and canonical resting-state networks, in healthy humans. Fourteen healthy participants (8 females; age [mean ± SD] = 27.93 ± 9.86) completed the study. Following dopamine depletion, the caudate showed reduced connectivity with the medial prefrontal cortex (mPFC) (Cohen's d = 1.89, p<.0001). Moreover, the caudate, putamen, globus pallidus, and midbrain all showed reduced connectivity with the occipital cortex (Cohen's d = 1.48-1.90; p<.0001-0.001). Notably, the dorsal caudate showed increased connectivity with the sensorimotor network (Cohen's d = 2.03, p=.002). AMPT significantly decreased self-reported motivation (t(13)=4.19, p=.001) and increased fatigue (t(13)=4.79, p=.0004). A greater increase in fatigue was associated with a greater reduction in connectivity between the substantia nigra and the mPFC (Cohen's d = 3.02, p<.00001), while decreased motivation was correlated with decreased connectivity between the VTA and left sensorimotor cortex (Cohen's d = 2.03, p=.00004). These findings help us to better understand the role of dopamine in basal ganglia function and may help us better understand neuropsychiatric diseases where abnormal dopamine levels are observed., Competing Interests: Declaration of Competing Interest The authors declare no financial conflicts of interest related to the study., (Copyright © 2022 Elsevier B.V. and ECNP. All rights reserved.)

Purpose: Heating of gradient coils and passive shim components is a common cause of instability in the B 0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered during MR spectroscopy (MRS) to assess the need for real-time field-frequency locking on MRI scanners by comparing field drift data from a large number of sites., Method: A standardized protocol was developed for 80 participating sites using 99 3T MR scanners from 3 major vendors. Phantom water signals were acquired before and after an EPI sequence. The protocol consisted of: minimal preparatory imaging; a short pre-fMRI PRESS; a ten-minute fMRI acquisition; and a long post-fMRI PRESS acquisition. Both pre- and post-fMRI PRESS were non-water suppressed. Real-time frequency stabilization/adjustment was switched off when appropriate. Sixty scanners repeated the protocol for a second dataset. In addition, a three-hour post-fMRI MRS acquisition was performed at one site to observe change of gradient temperature and drift rate. Spectral analysis was performed using MATLAB. Frequency drift in pre-fMRI PRESS data were compared with the first 5:20 minutes and the full 30:00 minutes of data after fMRI. Median (interquartile range) drifts were measured and showed in violin plot. Paired t-tests were performed to compare frequency drift pre- and post-fMRI. A simulated in vivo spectrum was generated using FID-A to visualize the effect of the observed frequency drifts. The simulated spectrum was convolved with the frequency trace for the most extreme cases. Impacts of frequency drifts on NAA and GABA were also simulated as a function of linear drift. Data from the repeated protocol were compared with the corresponding first dataset using Pearson's and intraclass correlation coefficients (ICC)., Results: Of the data collected from 99 scanners, 4 were excluded due to various reasons. Thus, data from 95 scanners were ultimately analyzed. For the first 5:20 min (64 transients), median (interquartile range) drift was 0.44 (1.29) Hz before fMRI and 0.83 (1.29) Hz after. This increased to 3.15 (4.02) Hz for the full 30 min (360 transients) run. Average drift rates were 0.29 Hz/min before fMRI and 0.43 Hz/min after. Paired t-tests indicated that drift increased after fMRI, as expected (p < 0.05). Simulated spectra convolved with the frequency drift showed that the intensity of the NAA singlet was reduced by up to 26%, 44 % and 18% for GE, Philips and Siemens scanners after fMRI, respectively. ICCs indicated good agreement between datasets acquired on separate days. The single site long acquisition showed drift rate was reduced to 0.03 Hz/min approximately three hours after fMRI., Discussion: This study analyzed frequency drift data from 95 3T MRI scanners. Median levels of drift were relatively low (5-min average under 1 Hz), but the most extreme cases suffered from higher levels of drift. The extent of drift varied across scanners which both linear and nonlinear drifts were observed., Competing Interests: Declaration of Competing Interest Jack J. Miller would like to acknowledge the support of a Novo Nordisk Research Fellowship run in conjunction with the University of Oxford. Francisco Reyes-Madrigal has served as a speaker for Janssen (Johnson & Johnson) and AstraZeneca. Marc Thioux and Pim van Dijk were supported by The Netherlands Organization for Health Research and Development (ZonMW) and the Dorhout Mees Foundation. All other authors have no conflict of interest to declare., (Copyright © 2021. Published by Elsevier Inc.)

Background: Hypothalamic-pituitary-thyroid (HPT) maturation has not been extensively evaluated using neonatal MRI, even though both structures are visualized on MRI., Hypothesis: That signal intensity and volume of pituitary and thyroid (T) glands on MRI in neonates may be interrelated., Study Type: Retrospective., Subjects: In all, 102 participants., Field Strength/sequence: 3.0T, T 1 -weighted pointwise encoding time reduction with radial acquisition (PETRA)., Assessment: The volume of interest of the anterior pituitary (AP), posterior pituitary (PP), and T on MRI were defined on T 1 -PETRA by two radiologists, and volumes of AP (AP&#95;vol) and thyroid (T&#95;vol) were calculated. Gestational age (GA), chronological age (CA), GA+CA, birth weight (BW), and thyroid function were recorded. Mean and maximum signal intensities of AP, PP, and T were normalized using signals from the pons and spinal cord as follows: signal ratio of anterior pituitary/pons (AP/pons), signal ratio of posterior pituitary/pons (PP/pons), and signal ratio of thyroid/cord (T/cord) T/cord, respectively., Statistical Tests: Correlations between signal intensity and volume measures and GA, CA, GA+CA, and BW were assessed using Pearson's correlation coefficient or Spearman's rank correlation coefficient. Thyroid function analysis and T mean /cord, T max /cord, and T&#95;vol were evaluated using the Steel-Dwass test., Results: AP mean /pons correlated positively with GA (ρ = 0.62, P < 0.001) and BW (ρ = 0.74, P < 0.001), and negatively with CA (ρ = -0.86, P < 0.001) and GA+CA (ρ = -0.46, P < 0.001). PP mean /pons correlated positively with GA (ρ = 0.49, P < 0.001) and BW (ρ = 0.63, P < 0.001), and negatively with CA (ρ = -0.70, P < 0.001) and GA+CA (r = -0.38, P < 0.001). T mean /cord correlated positively with GA (ρ = 0.48, P < 0.001) and BW (ρ = 0.55, P < 0.001), and negatively with CA (ρ = -0.59, P < 0.001) and GA+CA (ρ = -0.22, P = 0.03). AP&#95;vol correlated positively with GA (ρ = 0.68, P < 0.001) and BW (ρ = 0.73, P < 0.001), and negatively with CA (ρ = -0.72, P < 0.001). T&#95;vol correlated positively with GA (ρ = 0.50, P < 0.001) and BW (ρ = 0.61, P < 0.001), and negatively with CA (ρ = -0.54, P < 0.001). AP mean /pons correlated positively with T mean /cord (ρ = 0.61, P < 0.001)., Data Conclusion: Signal and volume of pituitary and thyroid glands correlated positively with GA and BW, and negatively with CA in neonates., Level of Evidence: 4 TECHNICAL EFFICACY STAGE: 5., (© 2020 International Society for Magnetic Resonance in Medicine.)

Objectives: The aim of this study was to assess the accuracy, reliability, and cerebral microbleed (CMB) detection performance of 2-minute quantitative susceptibility mapping (QSM) from 3-dimensional echo-planar imaging (3D-EPI)., Materials and Methods: Gadolinium phantom study was conducted using 3D-EPI, single-echo time (TE), and multi-TE gradient-recalled echo (GRE) sequences on two 3-T magnetic resonance (MR) scanners to assess the accuracy between measured and theoretical susceptibility values. The institutional review board approved this prospective study, and 40 healthy volunteers were enrolled with written consent between April 2018 and October 2019. Each underwent 3D-EPI, single-TE, and multi-TE GRE sequences consecutively on one 3-T MR scanner, and QSMs were calculated to assess the reliability of 3D-EPI QSM. Intraclass correlation coefficient (ICC), linear regression, and Bland-Altman plots were calculated. Patients with CMB who underwent both 3D-EPI and GRE QSM scans were retrospectively enrolled. Two radiologists evaluated images independently, and Cohen κ coefficients were calculated to compare CMB detection performance., Results: Phantom study showed excellent validity of 3D-EPI QSM on both MR scanners: Skyra, R2 = 0.996, P < 0.001, ICC = 0.997, mean difference, -2 ppb (95% confidence interval [CI], -45 to 40 ppb); Prisma, R2 = 0.992, P < 0.001, ICC = 0.988, mean difference, 15 ppb (95% CI, -67 to 97 ppb). A human study of 40 healthy volunteers (59 ± 13 years, 25 women) showed excellent reliability with 3D-EPI QSM for both single-TE and multi-TE GRE (R2 = 0.981, P < 0.001, ICC = 0.988; R2 = 0.983, P < 0.001, ICC = 0.990, respectively), supported by a Bland-Altman mean difference of 4 ppb (95% CI, -15 to 23 ppb) for single-TE GRE and 3 ppb (95% CI, -15 to 20 ppb) for multi-TE GRE. The CMB detection performance evaluation from 38 patients (51 ± 20 years, 20 women) showed almost perfect agreement between 3D-EPI and GRE QSM for both raters (κ = 0.923 and 0.942, P < 0.001)., Conclusions: Faster QSM from 3D-EPI demonstrated excellent accuracy, reliability, and CMB detection performance., Competing Interests: Conflicts of interest and sources of funding: This work was supported by JSPS KAKENHI grant number JP18K07711., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To compare the absolute values and repeatability of magnetic resonance fingerprinting (MRF) with 3000 and 1500 echoes/slice acquired in 41 s and 20 s (MRF3k and MRF1.5k, respectively)., Materials and Methods: MRF3k and MRF1.5k scans based on fast imaging with steady precession (FISP) were conducted using a 3 T scanner. Inter-scan agreement and intra-scan repeatability were investigated in 41 and 28 subjects, respectively. Region-of-interest (ROI) analysis was conducted on T1 values of MRF3k by two raters, and their agreement was evaluated using intraclass correlation coefficients (ICCs). Between MRF3k and MRF1.5k, differences in T1 and T2 values and inter-measurement correlation coefficients (CCs) were investigated. Intra-measurement repeatability was evaluated using coefficients of variation (CVs). A p value < 0.05 was considered statistically significant., Results: The ICCs of ROI measurements were 0.77-0.96. Differences were observed between the two MRF scans, but the CCs of the overall ROIs were 0.99 and 0.97 for the T1 and T2 values, respectively. The mean and median CVs of repeatability were equal to or less than 1.58% and 3.13% in each of the ROIs for T1 and T2, respectively; there were some significant differences between MRF3k and MRF1.5k, but they were small, measuring less than 1%., Discussion: Both MRF3k and MRF1.5k had high repeatability, and a strong to very strong correlation was observed, with a trend toward slightly higher values in MRF1.5k.

Background: Time-resolved angiography with interleaved stochastic trajectories (TWIST) is a keyhole imaging with frequent sampling of central k-space data and view-sharing for the peripheral k-space of dynamic phases. IT-TWIST is a technique to reconstruct images with a smaller temporal footprint using the same raw data obtained with TWIST by iterative reconstruction., Purpose: To compare image quality between TWIST and IT-TWIST in 3D pituitary DCE-MRI., Study Type: Retrospective observation study., Population: Fifty-one patients (23 men, 28 women) who underwent 3D pituitary DCE-MRI using TWIST between July 2016 and April 2017., Field Strength/sequence: 3T/TWIST and IT-TWIST., Assessment: Visual evaluation was conducted for image quality of delineation of the pituitary stalk and posterior lobe during the early arterial phase, cerebral white matter near the sella turcica, and the mass lesion. Bolus sharpness of the pituitary stalk, posterior lobe, and bilateral cavernous sinus was evaluated on the enhancement slope map calculated from TWIST and IT-TWIST. Temporal stability of intensity of the nonenhanced area was evaluated on temporal standard deviation (SD) maps calculated from TWIST and IT-TWIST., Statistical Tests: Paired t-test or Wilcoxon rank-sum test was used to test the differences between TWIST and IT-TWIST in both visual evaluation and region of interest evaluation., Results: Scores of visual evaluations for IT-TWIST were significantly better than those for TWIST (P < 0.001) in all items. Enhancement slope for IT-TWIST was significantly higher than that for TWIST in posterior lobe, and right and left cavernous sinus (P < 0.001). Temporal SD for IT-TWIST was significantly lower than that for TWIST in all items, with statistical significance (P < 0.001)., Data Conclusion: IT-TWIST yielded better visualization, and better enhancement slope, and less temporal SD compared with TWIST in 3D pituitary DCE-MRI. Evidence Level: 4 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:1497-1506., (© 2019 International Society for Magnetic Resonance in Medicine.)

Delay discounting (DD) represents decreased subjective value for delayed reward relative to the same reward at present. The concept of DD has been applied for pathophysiology of addiction and psychiatric disorders. However, the detailed neuroimaging correlates of DD underlying pathophysiology still remain unclear. Thus, we conducted a systematic review to investigate neural correlates of DD on magnetic resonance imaging studies among addiction and psychiatric disorders. Specific search terms were set on PubMed to identify relevant articles. Initial search identified 551 records and 31 studies met the inclusion criteria. The present review revealed that greater DD was correlated with increased activity in areas related to reward evaluation and prediction as well as decreased activity in areas related to cognitive control. Healthy controls showed smaller changes in activities of these areas associated with DD when compared to patient groups. As the neural basis related to DD, three neural networks have been proposed that are associated with the actions of short-term interests and long-term benefits. Among the three potential neural networks on DD, the first one included the ventromedial prefrontal cortex and ventral striatum and implicated in evaluating reward values, the second network included the anterior cingulate cortex and linked to cognitive control, and the third network included the middle temporal gyrus and was involved in predictions and affection. This review generated consistent findings on the neural basis of DD among patients with addiction and psychiatric disorders, which may represent the pathophysiology related to DD and impulsivity of mental illness., Competing Interests: Declaration of Competing Interest YN has received a Grant-in-Aid for Young Scientists (KAKENHI), a research grant from Japan Agency for Medical Research and development (AMED), an investigator-initiated clinical study grant from TEIJIN PHARMA LIMITED. YN also receives research grants from Japan Health Foundation, Meiji Yasuda Mental Health Foundation, Mitsui Life Social Welfare Foundation, Takeda Science Foundation, SENSHIN Medical Research Foundation, Health Science Center Foundation, Mochida Memorial Foundation for Medical and Pharmaceutical Research, and Daiichi Sankyo Scholarship Donation Program. He has received research supports from Otsuka Pharmaceutical, Shionogi, and Meiji Seika Pharma. YN also receives equipment-in-kind supports for an investigator-initiated study from Magventure Inc., Inter Reha Co., Ltd., Rogue Resolutions Ltd., and Miyuki Giken Co., Ltd. SN has received research support from Japan Society for the Promotion of Science (Grant-in-Aid for Young Scientists A, Grants-in-Aid for Scientific Research B, and Grants-in-Aid for Scientific Research C), Japan Agency for Medical Research and development (AMED), Japan Research Foundation for Clinical Pharmacology, Naito Foundation, Uehara Memorial Foundation, Takeda Science Foundation, Daiichi Sankyo Research Program, and Novartis Research Program, manuscript fees or speaker's honoraria from Meiji-Seika Pharma, Otsuka Pharmaceutical, Dainippon-Sumitomo Pharma and Yoshitomi Yakuhin within the past three years. MM has received grants or speaker's honoraria from Asahi Kasei Pharma, Astellas Pharmaceutical, Daiichi Sankyo, Dainippon-Sumitomo Pharma, Eisai, Eli Lilly, GlaxoSmithKline, Janssen Pharmaceutical, Meiji-Seika Pharma, Mochida Pharmaceutical, MSD, Novartis Pharma, Otsuka Pharmaceutical, Pfizer, Shionogi, Takeda, Tanabe Mitsubishi Pharma, and Yoshitomi Yakuhin within 3 years. Other authors have no financial or other relationship relevant to the subject of this manuscript., (Copyright © 2019 Elsevier Inc. All rights reserved.)

To evaluate the diagnostic accuracy of prostate magnetic resonance imaging (MRI), we compared MRI findings with the results of biopsy as well as findings from specimens following total prostatectomy. The subjects consisted of 260 males who showed a prostate specific antigen (PSA) level in the gray zone (4 ng/ml ≤PSA <10 ng/ml) and also underwent digital rectal examination (DRE), transrectal ultrasound (TRUS), and MRI prior to prostate biopsy between April 2005 and December 2009. In Evaluation 1, the results of DRE/TRUS/MRI were compared with those of prostate biopsy. The biopsy-positive rate was higher in males positive in each examination. However, 24.8% of males negative in all examinations were biopsypositive. Thus, these examinations were considered to be inappropriate for secondary screening. In evaluation 2, the prostate was divided into 4 regions, and the findings from specimens following total prostatectomy were compared with MRI findings in each region. For the region containing prostate cancer, MRI showed a sensitivity of 26.0%, specificity of 98.3%, positive predictive value of 96.2%, and negative predictive value of 44. 4%. In patients with a Gleason score ≥7, cancer foci were more frequently detectable using MRI. MRI prior to prostate biopsy in patients in the PSA gray zone is inappropriate for secondary screening due to its low sensitivity. However, by virtue of its high positive predictive value, MRI is useful for determining patients indicated for biopsy, as well as DRE and TRUS. Accurate evaluation of the localization of all cancer lesions is difficult using MRI. However, when MRI findings are present, they frequently indicate the cancer lesion, which may be useful information for treatment.

Purpose: To determine the signal enhancement characteristics of tumors after administration of a metalloporphyrin derivative, HOP-9P (13, 17-bis (1-carboxypropionyl) carbamoylethyl-3, 8-bis (1-phenylpropyloxyethyl)-2, 7, 12, 18-tetramethyl-porphyrinato manganese (III)) and to determine whether HOP-9P is tumor-necrosis specific., Materials and Methods: Ten C3H/He mice bearing a SCC VII tumor in the right flank were examined using T1-weighted conventional spin echo magnetic resonance (MR) imaging before contrast injection, and five minutes, one hour, and 24 hours after intravenous administration of 0.1 mmol/kg of HOP-9P. Following the imaging schedule, the mice were sacrificed, and sectioned in the same axial planes as the MR images. Based on an MR imaging-histopathologic correlation, mean signal intensities were measured, and signal-to-noise ratios (SNR) were calculated for both pure viable component and admixture of necrotic and viable component of the tumor., Results: Mean SNR of the pure viable component peaked at one hour (35.0 +/- 3.8) and maintained that level until 24 hours (34.6 +/- 3.6). Mean SNR of the admixture of necrotic and viable component peaked at 24 hours (44.3 +/- 12.1)., Conclusion: Although different enhancement patterns were seen between the pure viable component and the admixture of necrotic and viable component, HOP-9P enhanced both of the two components., (Copyright 2004 Wiley-Liss, Inc.)

Study Design: A cohort study., Objective: To determine the frequency of swelling of the spinal cord with an intramedullary lesion occurring after laminoplasty for nontraumatic cervical myelopathy and the possible mechanism of postoperative motor paresis of the upper extremity., Summary of Background Data: Postoperative enlargement of the spinal cord with an intramedullary lesion after decompression surgery for cervical stenotic myelopathy has been reported. But the frequency of the incidence remains unknown. Postoperative motor paresis occurring mainly in the C5 and C6 segments is known but various theories on its etiology exist, including the root involvement hypothesis and the spinal cord impairment hypothesis. Thus, the etiology is controversial., Methods: One hundred fourteen patients with cervical stenotic myelopathy were included in this study. All of them underwent preoperative magnetic resonance imaging and postoperative magnetic resonance imaging 3 weeks after surgery. We watched for the occurrence of postoperative neurologic deterioration including paralysis of the upper extremities. We also observed the presence or absence of postoperative abnormal expansion of T2 high-signal intensity areas on magnetic resonance imaging in the spinal cord., Results: Seven patients (6.1%) showed postoperative abnormal expansion of the T2 high-signal intensity area; 3 of the 7 were asymptomatic. A total of 9 patients (7.9%) experienced unilateral upper motor paresis after surgery. In 4 of the 9 cases, paresis of the unilateral deltoid, biceps and brachialis muscles (proximal paresis) occurred between 4 and 6 days after surgery. None of the 4 showed postoperative abnormal expansion of the T2 high-signal intensity area. In 3 other of the 9 patients, distal paresis occurred just after surgical intervention. Two of the 3 showed postoperative abnormal expansion of the T2 high-signal intensity area and 1 showed slight expansion of the area. In the other 2 cases, diffuse paresis occurred, and their postoperative magnetic resonance imaging showed abnormal expansion of the T2 high-signal intensity area., Conclusions: Spinal cord enlargement with abnormal expansion of the T2 high-signal intensity area, although not common, is an unpreventable complication after laminoplasty. This was strongly related with distal and diffuse type of postoperative paresis of the upper extremity without deterioration of lower motor function, but was little associated with a proximal type of paresis, so-called C5 and C6 palsies.

Objective: To evaluate the hypothesis that the extent of corpus callosum injury indicates the depth of shearing lesions in the central brain structure and therefore relates to the clinical severity of diffuse axonal injury., Methods: A simple and objective procedure for semiquantitative analysis of magnetic resonance images (MRI)-the maximum signal intensity ratio (MSIR)-was employed prospectively in 21 patients with diffuse axonal injury but without apparent injury to the ventral pons. All were diagnosed using serial combination MRI scans of fluid attenuated inversion recovery (FLAIR) and T2* weighted gradient echo imaging during the initial two weeks after the injury. The signal intensity ratio between the two regions of interest-the corpus callosum and the normal appearing ventral pons-was calculated serially in mid-sagittal and parasagittal FLAIR image sections in each patient. The MSIR during the study period was determined as a semiquantitative index of corpus callosum injury in each patient. The correlations between MSIR and the duration of unconsciousness, Glasgow outcome scale at six months, and the presence of apparent midbrain injury were investigated., Results: The mean (SD) MSIR value was 1.12 (0.18) at 7.4 (3.1) days after the injury (n = 21). MSIR correlated strongly with the duration of unconsciousness (n = 19, R(2) = 0.74, p < 0.0001), and was higher in patients with both an unfavourable GOS outcome (p = 0.020) and apparent midbrain injury (p < 0.001)., Conclusions: MSIR, which is a simple and objective procedure for semiquantitative analysis of corpus callosum damage in diffuse axonal injury, correlated with clinical severity. A high MSIR value may indicate the presence of concomitant midbrain injury.

The performance of a newly developed potential tumor-seeking magnetic resonance (MR) contrast agent alpha-Aqua-13,17-bis(1-carboxypropionyl) carbamoylethyl-3,8-bis(1-phenethyloxyethyl)-beta-hydroxy-2,7,12,18-tetramethyl-porphyrinato manganese (III) (HOP-8P) was tested using a mouse model. Tumor-bearing (SCC-VII) mice were imaged using a 1.5T MR imager before and after intravenous administration of 0.1 mmol/kg of HOP-8P. A biodistribution analysis was performed using an optical emission spectrometer. Significant enhancement of the transplanted tumor was observed in MR images 24 h after intravenous injection of HOP-8P. The biodistribution assessment of manganese also correlated with the results of the imaging study. During the 24-h period following contrast administration, HOP-8P was consistently cleared from the circulation, liver, kidneys, and muscle; however, it was progressively accumulated within the tumor. HOP-8P is a promising tumor-seeking metalloporphyrin MR contrast agent with a wide imaging window., (Copyright 2002 Wiley-Liss, Inc.)

The purpose of the study is to evaluate the tumour enhancing characteristics and biodistribution of a newly developed metalloporphyrin derivative, HOP-9P (13, 17-bis (1-carboxypropionyl) carbamoylethyl-3, 8-bis (1-phenylpropyloxyethyl)-2,7,12,18-tetra- methyl-porphynato manganese (III)). Seven mice bearing SCC VII tumours were imaged using T1-weighted conventional spin echo magnetic resonance images before and 5 min, 2 h and 24 h after intravenous injection of 0.1 mmol/kg of HOP-9P. For the acquired images, signal intensities of the tumour, muscle and oil-phantom were measured. Then, tumor/oil and tumor/muscle signal intensity ratios were calculated. Nineteen mice were sacrificed before or after the administration of HOP-9P (at 5 min, 2 h and 24 h), and the biodistribution of manganese in the tumour, muscle, liver, blood and kidneys was measured using optical emission spectrometers and was expressed as micrograms of manganese per gram of tissue. The tumour/muscle signal intensity ratio at 24 h (3.18 +/- 0.34) was significantly higher than precontrast ratio (1.77 +/- 0.20) (P < 0.05). The biodistribution assessment of manganese demonstrated that HOP-9P gradually and consistently accumulated in the tumour to reach the highest concentration at 24 h (3.49 +/- 1.22 micro gMn/g). It is concluded that HOP-9P is a potential tumour-specific MR contrast agent., (Copyright 2001 Cancer Research Campaign.)

Purpose: We have developed an intraoperative optical tracking-based navigational system that allows localization in the operative space. Using three-dimensional reconstruction, this system has provided precise spatial information for intraoperative cortical mapping in patients with intractable epilepsy in whom the lesion lies close to eloquent cortex., Methods: A 23-year-old man with intractable complex partial seizures (CPS) presented to our institution. Proton-density magnetic resonance imaging (MRI) showed a 3-cm lesion which lay 2 cm beneath the left frontal operculum. A three-dimensional model of the patient was reconstructed using MR modalities. Intraoperatively, subdural grid and strips were placed over the lesion and their electrodes were registered to the three-dimensional model, which was displayed on a monitor. The navigational system was used to localize each electrode on the three-dimensional model. By the second operation, the sites of seizure activity were established and recorded on the three-dimensional model. A bipolar stimulator was also used to determine the speech area., Results: The lesion, which proved to be cortical dysplasia, was removed completely and the cortical speech area was avoided. During the postoperative period, the patient had no neurological symptoms and no seizure activity., Conclusions: The localization of a lesion and its correlation with epileptogenic foci is important in optimizing treatment in patients with cortical dysplasia. Our navigational system provided accurate localization of the lesion and correlation with the epileptogenic focus and related eloquent cortex. We believe that the safe removal of the lesion was facilitated by this system.

Background: Image-based scalp localization methods currently used are complex and not standardized. The authors have developed a simple yet accurate method for craniotomy localization using multiplanar reconstruction (MPR) algorithms., Methods: In this method, the goal is to localize a projected point (defined as T) of the center of the lesion on the scalp. An oblique coronal plane is reformatted using a patient's magnetic resonance (MR) images with MPR algorithms to include both the center of the lesion and bilateral external auditory meati. Then the distance between T and the ipsilateral external auditory meatus or sagittal suture (defined as S) is measured along the scalp contour in the plane. The distance between the bregma and S is also measured. These distances are used for scalp localization, using a tape measure in the operating room., Results: We have had successful scalp localization in six clinical cases. It took about 3 min to measure each distance on the MR console., Conclusion: This method for craniotomy planning using MPR algorithms is simple and sufficiently accurate.

We have used MRI-based three-dimensional (3D) reconstruction and a real-time, frameless, stereotactic navigation device to facilitate the removal of seizure foci in children suffering from intractable epilepsy. Using this system, the location of subdural grid and strip electrodes is recorded on the 3D model to facilitate focus localization and resection. Ten operations were performed, including 2 girls and 8 boys ranging in age from 3 to 17, during which 3D reconstruction and surgical instrument tracking navigation was used. In all the cases, the patients tolerated the procedure well and showed no postoperative neurological deficits. We believe this to be a valuable tool for a complete and safe resection of seizure foci, thereby reducing the incidence of postoperative neurological deficits and significantly improving the overall quality of life of the patients.

Objective: We have treated patients with brain surface tumors by using video registration of a three-dimensional image to the surgical field, to identify eloquent cortices, localize the lesions, and define the tumor margins. "Skin-to-skin" registration using the skin surface to produce alignment was performed earlier but was difficult in areas with few prominent registration landmarks. For this reason, "vessel-to-vessel" registration using the cortical vessels as fiducials was applied to 17 cases, to improve accuracy. This article presents the advantages and limitations of vessel-to-vessel registration, as determined from the data for these cases. The accuracy is also estimated., Methods: A three-dimensional model was reconstructed from magnetic resonance imaging data, and a two-dimensional projection was superimposed on the video image of the actual surgical field. The tumor was resected with guidance from the registered video image. The two-dimensional projection accuracy of vessel-to-vessel registration was compared with that of skin-to-skin registration by using a phantom study., Results: All 17 tumors underwent gross total resection, and the patients experienced no major permanent neurological deficits. In the phantom study, the two-dimensional, projected, target registration error of a tumor with skin-to-skin registration was estimated as 8.9 +/- 5.3 mm and that with vessel-to-vessel registration was 1.3 +/- 1.4 mm (99th percentile confidence intervals, 24.8 and 5.5 mm, respectively)., Conclusion: Video registration using cortical surface vessels is practical and improves two-dimensional projection accuracy significantly, compared with skin registration.

A conjugate of manganese-metalloporphyrin and gadolinium (Gd)-diethylenetriaminepenta-acetic acid (Gd-ATN10) was developed as a tumor-specific enhancement agent for magnetic resonance (MR) imaging. Gd-ATN10 was evaluated in an experimental 9L gliosarcoma rat tumor model. T1-weighted MR imaging showed enhancement of the tumor which persisted for up to 24 hours. Gd concentration measurement by inductively coupled plasma atomic emission spectroscopy revealed the peak Gd concentration was reached after 30 minutes and Gd was retained in the blood and tumor up to 24 hours. There was no uptake of Gd in the normal brain and little in the skin. Gd-porphyrin derivatives are potentially useful agents for tumor diagnosis on MR imaging and for neutron capture therapy.

ATN-10, Mn-metalloporphyrin, has been developed as a tumor selective contrast agent for magnetic resonance (MR) imaging. To investigate the tumor specificity of ATN-10, we produced three experimental in vivo models; rat bran tumor (9L glioma) model, vasogenic (cold injury) and cytotoxic brain edema (24-hour MCA occlusion) models. The time course of contrast enhancement was compared after intravenous injection of ATN-10 or Gd-DTPA, measuring the signal intensity of the region of interest. After ATN-10 administration, the 9L glioma model showed early (5 min) and delayed (24 hr-) peak enhancement whereas the cold injury model showed only early enhancement and the 24-hour MCA occlusion model did not show significant enhancement. After Gd-DTPA administration, all three models showed similar pattern of only early enhancement. As a contrast agent for MR imaging, ATN-10 showed different behavior than Gd-DTPA in demonstrating the blood-brain barrier disruption and moreover ATN-10 showed selective enhancement in experimental brain tumors.

A new information-theoretic approach is presented for finding the registration of volumetric medical images of differing modalities. Registration is achieved by adjustment of the relative position and orientation until the mutual information between the images is maximized. In our derivation of the registration procedure, few assumptions are made about the nature of the imaging process. As a result the algorithms are quite general and can foreseeably be used with a wide variety of imaging devices. This approach works directly with image data; no pre-processing or segmentation is required. This technique is, however, more flexible and robust than other intensity-based techniques like correlation. Additionally, it has an efficient implementation that is based on stochastic approximation. Experiments are presented that demonstrate the approach registering magnetic resonance (MR) images with computed tomography (CT) images, and with positron-emission tomography (PET) images. Surgical applications of the registration method are described.

A fifty-year-old woman was admitted to our hospital because of an abnormal shadow on a chest X-ray film. She was asymptomatic. Chest X-ray film showed a scimitar-like vessel in the right lung, dextroposition of the heart, and hypoplasia of the right pulmonary artery. MRI revealed that the scimitar vein was anomalous pulmonary venous return from the right lung. Normal venous return from the right lower lobe to the left atrium was confirmed by pulmonary artery angiography. MRI findings have been useful in the diagnosis of scimitar syndrome.

We report a case of basilar artery migraine with transient MRI and EEG abnormalities. A 25-year-old male medical student developed a right occipital throbbing headache one hour after the abrupt onset of vertigo, nausea, left-sided homonymous hemianopsia and nystagmus. All of his complaints subsided the following day. He had suffered from attacks of headache accompanied by the same type of aural symptoms almost every ten days. He was therefore diagnosed as having basilar artery migraine. CT scans during the period of recurrent migraine demonstrated no abnormalities, while T2-weighted MR images revealed a high signal intensity region in the right occipital cortex and adjacent white matter perfused by rami temporales of the right posterior cerebral artery. Cerebral hypoperfusion was detected by a SPECT scanner in the right posterior region, where EEG recorded during the migraine attack demonstrated paroxysmal-localized sharp waves. MRI and EEG performed two months after the last attack showed no obvious abnormalities along with clinical disappearance of the migraine attacks. We found few reports of transient MRI changes associated with migraine. This case suggests that transient changes in MR images reflect vasogenic edema caused by migraine.

The cerebral lesions in tuberous sclerosis are of three kinds: subependymal nodules, cortical tubers, and cluster of heterotopic cells in the white matter. Understanding of these hamartomas is still incomplete even with modern imaging modalities. Magnetic resonance (MR) images of ten patients with tuberous sclerosis were reviewed and compared to computed tomographic (CT) scans and to the clinical severity of the disease. T2 weighted spin echo (TR = 1800, TE = 120) images and inversion recovery (TR = 2100, TI = 500-600, TE = 40) images were obtained at the same axial planes. Periventricular nodules were better seen, because of their calcifications, with CT than with MR imaging. They were demonstrated as iso- to low intensity depending on the amount of calcification on T2 weighted images, and as a similar intensity to the white matter on IR images. Small peripheral lesions in the hemispheres, which were only occasionally seen as small low density areas on CT scans, were well demonstrated on MR images. These foci were hyperintense on T2 weighted images, and hypointense on IR images. Exact location of these was not in the cortex, but in the subcortical white matter. The findings indicate that these foci represent the pathologically well known demyelinating foci, which are commonly present under the cortical tuber, but may be independent of them. Cortical tubers were not confidently identified, which suggested that they might have similar intensity to the cortical gray matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance (MR) imaging of a 17-year-old girl with subacute sclerosing panencephalitis (SSPE) was done several times to monitor the morphological changes and clinical course of the disease by comparison with computed tomographic (CT) scans. The MR image showed lesions that corresponded to the clinical symptoms in the early stages where no abnormalities appeared on the CT scans. The MR images delineated the extent of abnormal areas more clearly than the CT scans. However, the course of neurological manifestations did not always correspond to the MR findings. Serial MR imaging was useful in the detection and observation of the stages and clinical progress of SSPE.

MR imaging of the brain was performed in eight patients with mucopolysaccharidosis (MPS). Two had MPS I S, one had MPS IIA, two had MPS IIB, two had MPS IIIB, and one had MPS VI. In the patients with MPS IIA and MPS VI, T1 and T2 were prolonged in various areas of the cerebral white matter. These findings seemed to correspond with the development of pathologic changes in MPS, such as perivascular pits in the white matter observed on slices of the fixed brain. In the patients with MPS IIA and MPS IIIB, the white matter did not show the proper signal intensity, which suggested that myelination was insufficient and that infiltration or deposition of glycosaminoglycan had occurred; this was consistent with the association of these two types with mental retardation. In the patients with MPS I S, no intracranial abnormalities were detected on MR images. MR imaging of the brain may be used to obtain a differential diagnosis of the various types of MPS, to estimate the extent of mental retardation, and to monitor the progress of this disease.