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Objective: Ultra-high-field B0 ≥ 7 tesla (7T) cardiovascular magnetic resonance (CMR) offers increased resolution. However, electrocardiogram (ECG) gating is impacted by the magneto-hydrodynamic effect distorting the ECG trace. We explored the technical feasibility of a 7T magnetic resonance scanner using an ECG trigger learning algorithm to quantitatively assess cardiac volumes and vascular flow. Methods: 7T scans were performed on 10 healthy volunteers on a whole-body research MRI MR scanner (Siemens Healthineers, Erlangen, Germany) with 8 channel Tx/32 channels Rx cardiac coils (MRI Tools GmbH, Berlin, Germany). Vectorcardiogram ECG was performed using a learning phase outside of the magnetic field, with a trigger algorithm overcoming severe ECG signal distortions. Vectorcardiograms were quantitatively analyzed for false negative and false positive events. Cine CMR was performed after 3rd-order B0 shimming using a high-resolution breath-held ECG-retro-gated segmented spoiled gradient echo, and 2D phase contrast flow imaging. Artefacts were assessed using a semi-quantitative scale. Results: 7T CMR scans were acquired in all patients (100%) using the vectorcardiogram learning method. 3,142 R-waves were quantitatively analyzed, yielding sensitivity of 97.6% and specificity of 98.7%. Mean image quality score was 0.9, sufficient to quantitate both cardiac volumes, ejection fraction, and aortic and pulmonary blood flow. Mean left ventricular ejection fraction was 56.4%, right ventricular ejection fraction was 51.4%. Conclusion: Reliable cardiac ECG triggering is feasible in healthy volunteers at 7T utilizing a state-of-the-art three-lead trigger device despite signal distortion from the magnetohydrodynamic effect. This provides sufficient image quality for quantitative analysis. Other ultra-high-field imaging applications such as human brain functional MRI with physiologic noise correction may benefit from this method of ECG triggering.

Introduction: This study aimed to compare the apparent diffusion coefficient (ADC) values of different brain areas between two groups of intrauterine growth restricted (IUGR) foetuses and control cases. Material and methods: A total of 38 foetuses with IUGR and 18 normal control foetuses with similar gestational age were compared using a 3T magnetic resonance scanner. IUGR cases included 23 foetuses with clinical severity signs (group A) and 15 foetuses without clinical severity signs (group B). ADC values were measured in different brain regions and compared among groups. Foetuses with structural brain abnormalities were excluded from the study. Results: All foetuses had normal foetal structural brain anatomy. Head circumference (HC) < 5% was more common in IUGR group A compared to IUGR group B (56.5% vs. 13.3%, p < 0.0001). In comparison to the normal group, the ADC values in IUGR foetuses were significantly lower in cerebellar hemispheres (CH) (1.239 vs. 1.280.5 × 10-3 mm2/s, p = 0.045), thalami (1.205 vs. 1.285 × 10–3 mm2/s, p = 0.031) and caudate nucleus (CN) (1.319 vs. 1.394 × 10-3 mm2/s, p = 0.04). However, there were no significant differences in ADC values between IUGR subtypes. Among all brain regions, pons had the lowest ADC values. Conclusions: ADC values of thalami, CN, and CH were significantly lower in IUGR than control foetuses, while there was no significant difference among IUGR groups. Further studies are needed to evaluate the prognostic value of ADC changes in IUGR foetuses.

Magnetic resonance imaging (MRI) is used for soft tissue pathology diagnosis and assistance with targeted lesion procedures. However, limited physician access to patients in the magnetic resonance scanner bore requires iterative positioning and imaging, which extends the procedure time and increases patient risk. We present a teleoperated system and instrumented testbed for robotic MRI-guided needle biopsy, particularly targeting transperineal prostate biopsies. The device has a 1:1 kinematic mapping and uses a low-friction hydrostatic transmission based on antagonistic pairs of rolling diaphragms. It has three degrees of freedom (DOFs) and a passive two-DOF swivel, which holds a biopsy needle at the end-effector. Measured force hysteresis is 0.085 N (single DOF) and 0.44 N (full three-DOF manipulator) at the needle driving point. To quantitatively assess the system's haptic qualities, impulse modal testing for one DOF ( $>$ 300 Hz bandwidth) and three DOFs ( $>$ 40 Hz bandwidth) was conducted. Task performance was also assessed through membrane puncture testing with tissue phantoms; puncture events as low as 0.1 N are reliably detectable from transmission hydraulic pressure sensors.

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are non-invasive techniques for tissue characterization. MRI/MRS in small phantoms with a clinical magnetic resonance scanner requires the design and development of dedicated radiofrequency coils. This paper describes the simulation, design, and application of a 1H transmit/receive Helmholtz coil, suitable for MRI/MRS studies in small phantoms with a clinical 3T scanner. Coil inductance and resistance were analytically calculated by taking into account the conductors cross geometry while magnetic field and sample-induced resistance were calculated with magnetostatic approaches. Finally, the coil sensitivity was measured with the perturbing sphere method. Successively, a coil prototype was built and tested on the workbench and by acquisition of MRI and MRS data. Results show that such coil could provide a low cost and easy to build device for MRI/MRS experiments with a clinical scanner in small specimens.

Narayan Rai,1,* Maria Mananita Hipolito,1,* John W VanMeter,2 Riya Seth,3 Ayokunnumi Adenuga,3 Myeshia Shelby,4 Magdalena Misiak-Christian,5 Charles Nwaokobia,3 Kebreten F Manaye,5 Thomas O Obisesan,6 Evaristus Nwulia1,3 1Department of Psychiatry and Behavioral Sciences, Howard University, Washington DC, USA; 2Department of Neurology, Center for Functional and Molecular Imaging, Georgetown University Medical Center, Washington DC, USA; 3Evon Medics LLC, Elkridge, MD, USA; 4Howard University Graduate School, Washington DC, USA; 5Department of Physiology, Howard University, Washington DC, USA; 6Department of Medicine, Howard University, Washington DC, USA*These authors contributed equally to this workCorrespondence: Evaristus NwuliaDepartment of Psychiatry and Behavioral Sciences, Howard University, Washington DC, WA, USAEmail enwulia@howard.eduObjective: This study evaluated human Blood Oxygen Level-Dependent (BOLD) responses in primary and higher-order olfactory regions of older adults, using odor memory and odor identification tasks. The goal was to determine which olfactory and memory regions of interest are more strongly engaged in older populations comparing these two odor training tasks.Methods: Twelve adults 55– 75 years old (75% females) without intranasal or major neurological disorders performed repetitive odor memory and identification tasks using a 3-tesla magnetic resonance scanner. Odors were presented intermittently at 10-second bursts separated by 20-second intervals of odorless air. Paired t-tests were used to compare differences in the degree of activation between odor identification and odor memory tasks within individuals. An FDR cluster-level correction of p< 0.05 was used for multiplicity of tests (with a cluster-defining threshold set at p< 0.01 and 10 voxels).Results: Odor identification compared to memory (ie, odor identification > odor memory) contrasts had several areas of significant activation, including many of the classical olfactory brain regions as well as the hippocampus. The opposite contrast (odor memory > odor identification) included the piriform cortex, though this was not significant. Both tasks equally activated the piriform cortex, and thus when the two tasks are compared to each other this area of activation appears to be either absent (OI > OM) or only weakly observed (OM > OI).Conclusion: These findings from a predominantly African American sample suggest that odor identification tasks may be more potent than memory tasks in targeted olfactory engagement in older populations. Furthermore, repetitive odor identification significantly engaged the hippocampus – a region relevant to Alzheimer’s disease – more significantly than did the odor memory task. If validated in larger studies, this result could have important implications in the design of olfactory training paradigms.Keywords: blood oxygen level dependent responses, BOLD, odor memory, odor identification, olfactory engagement, olfactory training

The present study aimed to investigate the value of intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) in the preoperative prediction of the histologic differentiation of hepatocellular carcinoma (HCC). Seventy HCC patients were scanned with a 3.0 T magnetic resonance scanner. The values of apparent diffusion coefficient (ADC), slow apparent diffusion coefficient (D), fast apparent diffusion coefficient (D*), and the fraction of the fast apparent diffusion coefficient (f) were measured. Analysis of variance was used to compare the differences in parameters between groups with different degrees of histologic differentiation. p −3 mm2/s, 1.16 ± 0.17 × 10−3 mm2/s, 0.98 ± 0.21 × 10−3 mm2/s, and 1.06 ± 0.15 × 10−3 mm2/s, 0.88 ± 0.16 × 10−3 mm2/s, 0.76 ± 0.18 × 10−3 mm2/s, respectively, and all differences were significant. The D* and f values of the three groups were 32.87 ± 14.70 × 10−3 mm2/s, 41.68 ± 17.90 × 10−3 mm2/s, 34.54 ± 18.60 × 10−3 mm2/s and 0.22 ± 0.07, 0.23 ± 0.08, 0.18 ± 0.07, respectively, with no significant difference. When the cut-off values of ADC and D were 1.25 × 10−3 mm2/s and 0.97 × 10−3 mm2/s, respectively, their diagnostic sensitivities and specificities for distinguishing well differentiated HCC from moderately differentiated and poorly differentiated HCC were 73.3%, 85.5%, 86.7%, and 78.2%, and their areas under the ROC curve were 0.821 and 0.841, respectively. ADC and D values can be used preoperatively to predict the degree of histologic differentiation in HCC, and the D value has better diagnostic value.

Diffusion magnetic resonance imaging is a technique which has long been used to study white matter microstructure in vivo. Recent advancements in hardware and modelling techniques have opened up interest in disentangling tissue compartments in the grey matter. In this study, we evaluate the repeatability of soma and neurite density imaging in a sample of six healthy adults scanned five times on an ultra-strong gradient magnetic resonance scanner (300 mT/m). Repeatability was expressed as an intraclass correlation coefficient (ICC). Our findings reveal that measures of soma density (mean ICC \(=\) 0.976), neurite density (mean ICC \(=\) 0.959) and apparent soma size (mean ICC \(=\) 0.923) are highly reliable across multiple cortical and subcortical networks. Overall, we demonstrate the promise of moving advanced grey matter microstructural imaging towards applications of development, ageing, and disease.

Introduction Congenital heart diseases (CHD) are detected in 1% of children, often usually the first year of life; however, many defects are diagnosed later or remain undiagnosed. Both congenital and acquired disorders could affect the left ventricle (LV). First-line assessment includes echocardiography; nonetheless, because of intrinsic or technical limitations and artefacts, further investigation may be required. Cardiac Magnetic Resonance (CMR) is capable of providing anatomical and functional information without many of limitations and drawbacks of echocardiography. We describe CMR findings of misdiagnosed cases of two rare congenital LV abnormalities: isolated LV apical hypoplasia (ILVAH) and double-chambered LV (DCLV). Case report 1 (image A,B,D) An 18 yrs girl diagnosed with dilated cardiomyopathy (DCM) was submitted to our CMR Lab for a functional assessment. After birth, deep Q waves in the inferior leads were noted on the ecg, and an echocardiographic examination showed a dilated and hypokinetic LV. At 1 year of age, she underwent cardiac catheterization that excluded coronary arteries anomalies and confirmed a reduced LV systolic function. A diagnosis of idiopathic DCM was formulated and she was initiated with anticongestive therapy. During the follow-up she felt well with normal exercise tolerance, longitudinal echocardiography did not show any substantial modification over the years. In 2018, a CMR study was performed. Surprisingly, the cardiac apex was formed exclusively by the right ventricle, wrapped around the LV. The LV appeared spherical and truncated inferiorly, and the apical portion was missing; LV volumes and ejection fraction were normal; regional akinesia and subendocardial late gadolinium enhancement (LGE) were evident at the inferior wall. These findings were consistent of ILVAH. Case Report 2 (image C,E,F) A 24 yrs old boy with prenatal diagnosis of LV diverticulum came to our observation for a CMR study. He was asymptomatic, particularly, no palpitations or syncope were referred, nor arrhythmias were detected during the follow-up; exercise tolerance was normal. CMR showed a coarse muscle band in the LV cavity, extending from the apex to the posterior papillary muscle, thus delimiting a contractile accessory chamber. LV volumes and global systolic function were normal. The LV accessory chamber presented a normal structured free lateral wall with a normal systolic thikening, except at the apical infero-lateral segment where it appeared thinned and akinetic and showed LGE with a subendocardial pattern. These findings were consistent of DCLV. Conclusions the LV could be affected by many diseases with different etiological, clinical and morphological features. Compared to other imaging diagnostic modalities, CMR allows better definition of LV morphology, function and tissue characterization, becoming essential for LV abnormalities diagnosis and follow-up. Abstract P1336 Figure.

Objective: We aimed to evaluate whether human immunodeficiency virus (HIV)-positive patients with and without clinically significant memory deficits and healthy control participants differ on in vivo hydrogen-1 magnetic resonance spectroscopy (H-MRS) in the posterior cingulate gyri. Materials and Methods: In total, 21 HIV-positive patients with memory deficit (HIV+wMD) were compared with 15 HIV-positive patients without memory deficit (HIV+wOMD) and 22 sex-, age-, and education-matched control participants. Memory impairments were classified based on the participants’ performance on the Rey Auditory Verbal Learning Test. Short echo time (30 ms), single-voxel H-MRS was performed using a 1.5-T magnetic resonance scanner. Results: The HIV+wMD and HIV+wOMD groups had higher choline/creatine ratio in the posterior cingulate gyri than the control group. There were no significant metabolite ratio differences between the HIV+wMD and HIV+wOMD groups. Conclusion: HIV-positive patients with and without memory deficits had significantly higher choline/creatine ratios than controls in the posterior cingulate gyri, which may reflect cerebral inflammation, altered cell membrane metabolism, microgliosis, and/or astrocytosis. Resumo Objetivo: Nós avaliamos se os pacientes HIV-positivos com e sem déficits de memória clinicamente significativos e controles saudáveis diferem na espectroscopia de prótons do giro do cíngulo posterior, por ressonância magnética (RM) cerebral. Materiais e Métodos: Vinte e um pacientes HIV-positivos com déficit de memória foram comparados com 15 pacientes HIV-positivos sem déficit de memória e 22 controles, pareados por sexo, idade e escolaridade. As deficiências de memória foram classificadas por meio do desempenho no Teste de Aprendizagem Auditivo-Verbal de Rey. A espectroscopia de prótons foi realizada com tempo de eco curto (30 ms), por voxel único, no giro do cíngulo posterior, utilizando aparelho de RM de 1,5 T. Resultados: Os pacientes HIV-positivos com e sem déficit de memória apresentaram aumento da relação colina/creatina no giro do cíngulo posterior, comparados aos controles. Não houve diferenças significativas nas relações metabólicas no grupo HIV-positivo com déficit de memória, em relação ao grupo de pacientes HIV-positivo sem déficit. Conclusão: Pacientes HIV-positivos com e sem déficits de memória apresentaram relações colina/creatina significativamente aumentadas em relação aos controles, no giro do cíngulo posterior, o que pode refletir inflamação cerebral, alteração do metabolismo da membrana celular, microgliose e/ou astrocitose.

The article describes experiments on the detection of nuclear magnetic resonance (NMR) signals from nuclei other than protons on low field (0.5 T) clinical MR scanner. The possibility of obtaining NMR spectra and MR imaging (MRI) from nuclei with a high natural abundance (19F, 31P, 11B, 23Na), as well as isotope-enriched samples (13C and 2H), is presented. The possibilities of recording NMR spectra for low-sensitivity nuclei (13C, 29Si, 2H, 17O, 14N) are shown. Special attention is paid to the detection of NMR signal from perfluorocarbons (PFC). The examples of 19F MRI of PFC obtained in the in vivo study of both animals and human are presented. The 19F MRI of fluorinated gas, which can be used as a contrast agent for lung imaging, was also obtained. The opportunity of increasing 13C NMR signal from PFC by polarization transfer from fluorine nuclei is demonstrated. It was shown that 23Na can be detected in NMR spectroscopy and MRI of animal and human. The prospects of 17O NMR for technology applications are noticed.

A hybrid metasurface realized by a double array of brass wires inserted into two high-permittivity dielectric slabs at both sides was used to perform a magnetic resonance spectroscopy experiment at a 1.5 T clinical magnetic resonance scanner. The metasurface coupled inductively to a transceive birdcage body coil located within the scanner’s bore. The metasurface demonstrated an enhancement of the signal-to-noise ratio of the magnetic resonance spectroscopy experiment in vitro. Up to a signal-to-noise ratio gain of 7.4 for choline and creatine spectral lines was observed in the presence of the metasurface compared to the body coil alone.

In NF 1 patients, significant numbers of so-called unidentified bright objects (UBOs) can be found. The aim of the study was to investigate whether the detectability of UBOs increases at 3T by comparing Proton density-weighted images (PDw) with fluid-attenuated inversion recovery (FLAIR) sequences.A total of 14 NF1 patients (7 male, 7 female, between 8 and 26 years old, mean age 15.4 years) were examined by a 3T magnetic resonance scanner. The presence of UBOs was evaluated on PD-w and FLAIR images by 4 evaluators. Detectability was rated by a three-point scoring system: lesions which were "well defined/detectable", "suspicious" or "detected after a second look". The Wilcoxon signed-rank test was used for comparisons between the raters. The level of significance was P 0.05.Significantly more lesions were marked as "well defined/detectable" in the PD-w Sequence compared to FLAIR at 3T (P 0.001 for all four evaluators together, as well as for each evaluator separately). In particular, PD-w proved to be superior for detecting UBOs located in the medulla oblongata, dentate nucleus and hippocampal region, regardless of the level of the raters' experience.This is the first study which compares FLAIR and PD-w at 3T for the diagnosis of UBOs in NF1. At this field strength significantly more UBOs were detected in the PD-w compared to FLAIR sequences, especially for the infratentorial regions. As UBOs occur at very early stages of the disease in patients with suspected NF1, PD-w might aid in the early diagnosis when using 3T scanners.

Objective: To investigate the 1H-MRS characteristics of cerebral alveolar echinococcosis (CAE) treated by albendazole liposome. Materials and methods: Nine patients with 20 lesions proven histologically and clinically to be CAE positive were examined via conventional MRI and 2D multivoxel spectroscopy with a 3.0 T double gradient superconductivity magnetic resonance scanner. In patients who took medication regularly for at least one year, the levels of NAA, CR, Cho, MI, Lip, Lac, and other metabolites from the same lesion parenchyma were observed and then used to calculate NAA/Cr, NAA/Cho, NAA/(Cho+Cr), and (Lip+Lac)/Cr. Statistical analysis was performed using the Wilcoxon signed-rank test. Results: Comparisons between cMRI scans taken before patients began taking medication and cMRI scans taken after patients completed one year of regular medication, the volume of legions increased slightly, and the signals of lesions increased on T2WI. The medians and interquartile ranges of NAA/Cho, NAA/CR, NAA/(Cho+Cr), and (Lip+Lac)/Cr in the same lesions in CAE patients prior to treatment via albendazole liposomes were: 2.285 (1.388–3.655), 3.620 (2.173–5.165), 0.651 (0.552–0938), and 29 (15.219–41.609), respectively. The medians and interquartile ranges of NAA/Cho, NAA/CR, NAA/(Cho+Cr), and (Lip+Lac)/Cr in the same lesions in CAE patients after treatment via albendazole liposomes were: 5.120 (1.853–12.00), 6.120 (3.690–9.733), 0.900 (0.651–1.218), and 26.427 (16.536–49.904), respectively. Proton magnetic resonance spectroscopy images of patients with CAE before and after one year of treatment via albendazole liposomes were characterized by the increase of NAA with ratios of NAA/Cho, NAA/CR, and NAA/(Cho+Cr) increasing by different degrees. Compared with the same lesion before and after treatment twice, the differences were statistically significant (P 0.05). Conclusion: In patients with CAE, minimal change in CAE lesions imaged via conventional MRI, 1H-MRS was observed. Slight changes of cerebral alveolar echinococcosis lesions before and after treatment via albendazole liposome were observed, providing valuable imaging information for the treatment of CAE lesions.

Aggregation of tau into neurofibrillary tangles (NFTs) is characteristic of tauopathies, including Alzheimer's disease. Recent advances in tau imaging have attracted much attention because of its potential contributions to early diagnosis and monitoring of disease progress. Fluorine-19 magnetic resonance imaging (19F-MRI) may be extremely useful for tau imaging once a high-quality probe has been formulated. In this investigation, a novel fluorine-19–labeling compound has been developed as a probe for tau imaging using 19F-MRI. This compound is a buta-1,3-diene derivative with a polyethylene glycol side chain bearing a CF3 group and is known as Shiga-X35. Female rTg4510 mice (a mouse model of tauopathy) and wild-type mice were intravenously injected with Shiga-X35, and magnetic resonance imaging of each mouse's head was conducted in a 7.0-T horizontal-bore magnetic resonance scanner. The 19F-MRI in rTg4510 mice showed an intense signal in the forebrain region. Analysis of the signal intensity in the forebrain region revealed a significant accumulation of fluorine-19 magnetic resonance signal in the rTg4510 mice compared with the wild-type mice. Histological analysis showed fluorescent signals of Shiga-X35 binding to the NFTs in the brain sections of rTg4510 mice. Data collected as part of this investigation indicate that 19F-MRI using Shiga-X35 could be a promising tool to evaluate tau pathology in the brain. © 2017 Wiley Periodicals, Inc.

In developing countries, cardiovascular risk factors are poorly controlled, leading to high prevalence of cerebrovascular diseases. The aim of the study was to evaluate the burden of white matter lesions in magnetic resonance through the Fazekas scale in a population aged 75 + years living in the community, and to investigate possible associations between vascular lesions, cardiovascular risk factors and cognitive status. Subjects were selected from a community-based study on brain aging conducted in Caeté (Minas Gerais state), Brazil. Overall, 177 participants (112 cognitively healthy, 36 with cognitive impairment-no dementia and 29 with dementia), being 108 women, aged 79.3 ± 3.8 years, with 3.1 ± 2.9 years of educational level, underwent a 3 Tesla magnetic resonance scanner with fluid attenuated image recovery acquisition. Severity of white matter lesions was assessed through the Fazekas scale. Severe white matter lesions were present in 31.1% of the whole sample and in 25.0% of the cognitively healthy individuals. A significant association was found between severe white matter lesions and cognitive impairment (OR = 2.20, 95% CI 1.17–6.53; p = 0.021), as well as with hypertension (OR = 1.92, 95% CI 1.03–7.39; p = 0.043). In conclusion, a high prevalence of severe white matter lesions was observed in this elderly Brazilian population sample, and white matter lesions were associated with hypertension and cognitive status. Importantly, the prevalence of white matter lesions was also high in cognitively healthy subjects., Highlights • The ischemic cerebrovascular burden assessed by MRI in an elderly Brazilian community is very high. • MRI white matter lesions were associated with cognitive impairment and hypertension. • Even in cognitively healthy individuals the prevalence of ischemic cerebrovascular lesions was high.

Objectives: To quantify pancreatic fat content (PFC) in patients with newly diagnosed type 2 diabetes mellitus (T2DM) using proton magnetic resonance spectroscopy. Patients and Methods: Spectra of the pancreatic head, body, and tail were acquired by single-voxel point-resolved spectroscopy sequences on a 3.0-T magnetic resonance scanner in 59 newly diagnosed T2DM patients and 32 non-diabetics (controls). PFC values were calculated and compared between the patients and controls as well as among the head, body, and tail. Correlations were determined between PFC and age, body mass index (BMI), and serum triglyceride (TG) levels. Results: Mean fat fractions did not differ significantly (all Ps > 0.05) across the pancreatic head, body, and tail in either the T2DM group (15.14 ± 7.49%, 17.51 ± 7.74%, and 18.35 ± 7.58%, respectively) or the control group (12.27 ± 7.85%, 15.35 ± 8.53%, and 16.20 ± 10.02%, respectively). Overall, mean PFC values did not differ significantly (P > 0.05) between the T2DM group (16.82 ± 6.16%) and control group (14.56 ± 7.97%). Among T2DM patients, PFC did not correlate with age, TG levels, or BMI (r 0.05). Among non-diabetic controls, PFC correlated with BMI (r = 0.362, P = 0.042) and TG levels (r = 0.467, P = 0.007), but not with age (r 0.05). Conclusion: PFC in the head, body, and tail are similar for newly diagnosed T2DM patients and non-diabetic persons. PFC does not correlate with age, TG, or BMI in newly diagnosed T2DM patients.

Magnetic resonance-guided focused ultrasound is one of the emerging non-invasive technologies offering both image guidance and thermal monitoring. In recent years transcranial application of this technology is starting to impact heavily the neuroscience field. We present here the imaging protocol and the technological methods successfully used with a transcranial magnetic resonance-guided focused ultrasound system certified for clinical treatments of functional neurological disorders, integrated for the first time with a 1.5T magnetic resonance scanner. Compared to the body radiofrequency coil (the one commonly used with transcranial magnetic resonance-guided focused ultrasound system integrated with 3T magnetic resonance scanners), the use of a dedicated two channel coil enabled a signal-to-noise ratio gain up to five times higher.

Introduction: Urinary tract (UT) pathologies are common causes of morbidity presenting mainly as acute flank pain, obstructive uropathy, and hematuria with calculus being the commonest cause. Computed tomography (CT) (noncontrast, contrast enhanced and urography) of the kidney, ureter, and bladder region has been considered as the mainstay in evaluation of patients with UT symptoms. Limitations of radiation exposure and risks of contrast injection in CT have provided space for magnetic resonance urography (MRU) that has recently gain acceptance. However, MRU is limited by its availability and higher cost. Thus, with the aim of evaluating the scope of MRU in various UT pathologies, we planned a comparative study between CT scan and MRU. Materials and Methods: Thirty-five patients with UT symptoms (acute flank pain, obstructive uropathy, and hematuria) were evaluated with CT scan and MRU after obtaining approval from Institutional Ethics Committee and written informed consent from the participants of the study. CT scan was performed on 128-slice CT scanner while MRU was performed on 1.5T magnetic resonance scanner using the standard protocol. The data thus recorded in a single-blinded manner were analyzed using appropriate statistical methods and tools. Results: Compared with CT scan, MRU had a poor accuracy in detecting UT stones especially

The purpose of this study was to analyze if there is a significant correlation between the results of diffusionweighted imaging (DWI) and the expression of proliferating cell nuclear antigen (PCNA) in astrocytomas. The DWI scans of 19 different-grade astrocytomas were obtained on a 3 T magnetic resonance scanner. The average regional apparent diffusion coefficients (ADC) were measured. The positive expression of PCNA was determined immunohistochemically by using streptavidin-peroxidase complex staining, and was quantified by calculating its calibrated opacity density (COD) using an image analysis system. The average regional ADC and PCNA COD of low grade and high grade astrocytomas were compared. Correlations between regional ADC and PCNA COD were analyzed. The average regional ADC of high grade astrocytomas was significantly (t = 10.169, P = 0.000) less (0.687 ± 0.225 x 10-3 mm2/s) than that of low grade astrocytomas (1.572 ± 0.333 x 10-3 mm2/s). The PCNA COD (0.343 ± 0.052) of high grade astrocytomas was significantly (t=-7.858, P=0.000) greater than that (0.194 ± 0.012) of low grade astrocytomas. There were strong negative correlations between regional ADC and PCNA COD (r = -0.801, P = 0.000). The results demonstrated that DWI is helpful in evaluating cell proliferation and preoperatively grading astrocytomas by measuring regional ADC.

In this work, a superficial hyperthermia applicator was designed to be used in small animal studies. The applicator operates at 2.45 GHz and is compatible with a magnetic resonance scanner. A temperature controller was interfaced with the applicator to control the rate of change in temperature and the target temperature. Operation and robustness were validated through phantom and in vivo experiments.

Background To evaluate whether readout-segment echo-planar imaging (RS-EPI) can provide better image quality in assessing bladder cancer than single-shot echo-planar imaging (SS-EPI) and to compare quantitative imaging parameters derived from both techniques. Methods Seventy patients with bladder lesions were enrolled and underwent diffusion-weighted imaging on a 3 Tesla magnetic resonance scanner using axial RS-EPI and SS-EPI techniques. Two observers independently assessed the susceptibility, detectability, motion artefacts and blurring of the images using qualitative scores. The signal-to-noise ratio (SNR), signal intensity ratio (SIR), contrast-to-noise ratio (CNR) and ADC values of the bladder lesions were measured and compared between the two techniques and between two observers. Qualitative and quantitative comparisons of image quality were performed using the Wilcoxon signed-rank test and paired t-test. In addition, the agreement of the ADC measurements was evaluated using ICC values and Bland-Altman plots. Results Sixty-eight patients were included in the final analysis. The scores of image susceptibility, detectability and blurring for RS-EPI were significantly higher than those for SS-EPI (all p 0.05). The ICC values and Bland-Altman plots also showed excellent agreement between the measured ADC values of the bladder lesions. Conclusions The RS-EPI technique provides significantly better image quality in patients with bladder cancer than the SS-EPI technique, without a significant difference in the ADC value.

Introduction Oscillating gradient spin-echo (OGSE) sequences can shorten diffusion times by replacing the long-lasting diffusion-sensitizing gradients used in pulsed gradient spin-echo (PGSE) methods with rapidly oscillating gradients. To obtain information regarding the internal structure of choroid plexus cysts that appear hyperintense on diffusion-weighted imaging (DWI), we investigated the apparent diffusion coefficient (ADC) values acquired with a shorter diffusion time using an OGSE sequence. Material and methods Twenty-seven patients with choroid plexus cysts were scanned using a 3 T magnetic resonance scanner. DWI was performed with both OGSE and PGSE, with effective diffusion times (Δeff) of 6.5 and 35.2 ms, respectively. ADC values for choroid plexus cysts, white matter (WM), and cerebrospinal fluid (CSF) were measured. The ADC values obtained with the shorter and longer diffusion times were compared using the Wilcoxon signed-rank test. P Results The ADC values of choroid plexus cysts and WM were significantly higher at the Δeff of 6.5 ms on OGSE than with the Δeff of 35.2 ms on PGSE. The ADC values of CSF were significantly lower at the Δeff of 6.5 ms on OGSE than with the Δeff of 35.2 ms on PGSE. The ADC values of choroid plexus cysts were lower than the ADC values of CSF with Δeff of 35.2 and 6.5 ms. Conclusions The dependence of ADC values on the diffusion time in choroid plexus cysts suggested spatially restricted diffusion. In measurements obtained with short diffusion times, the lower ADC values for choroid plexus cysts in comparison with the CSF indicated the presence of spatially restricted diffusion and increased cyst viscosity.

ObjectiveTo use 4D-flow MRI to characterize hemodynamics of transverse and sigmoid sinus in venous pulsatile tinnitus (PT) patients and to investigate their differences vs healthy controls.MethodsA total of 21 patients with venous PT and 11 healthy controls were included in the retrospective study. All participants underwent 4D-flow and magnetic resonance venography scan in a 3.0T magnetic resonance scanner. All visualization, quantification, and analysis of 4D-flow data were performed using dedicated software. Two independent reviewers evaluated the existence of vortex or turbulence. Covariance analysis adjusted for age was used to compare average through-plane velocity (Vtp_avg), maximum through-plane velocity (Vtp_max), average velocity (Vavg), maximum velocity (Vmax), average blood flow (Flowavg), and pulsatility index (PI) between PT and control group.ResultsThere were hemodynamic differences between PT patients and healthy controls. Compared with the control group, the PT group showed significantly higher Vtp_avg, Vtp_max, Vavg, Vmax, and Flowavg, and slightly higher PI. For the assessment of flow pattern, inter-reader reproducibility was excellent (κ = 1.00). Vortex or turbulence was observed in PT patients with good sensitivity (86.4%) and specificity (90.9%). Drainage dominance was more frequently observed in patients (15/21, 71.4%) than healthy controls (4/11, 36.4%).ConclusionsSignificant hemodynamic differences were found between venous PT patients and healthy controls with 4D-flow MRI. Hemodynamic conditions could serve as noninvasive biomarkers for diagnosis and treatment evaluation of venous PT.Classification of evidenceThis study provides Class III evidence that 4D-flow MRI accurately identifies patients with venous PT.

Objective This is a comprehensive study to establish a diagnosis-specific gray matter deficit model for major depressive disorder (MDD) and panic disorder (PD). Method: We enrolled 53 patients with first-episode medication-naive PD, 54 healthy controls and 53 patients with first-episode medication-naive MDD in this study. They were age, handedness and gender matched. All participating subjects all received baseline structural scanning by the 3-Tesla magnetic resonance scanner. The optimized voxel-based morphometry was performed on the 3 groups of subjects and the ANOVA analysis was used to estimate the inter-group gray matter differences between each group. Results: The PD group had higher gray matter volume than MDD group in the right medial frontal cortex and right temporal gyrus. The PD group had gray matter reductions in the right inferior frontal gyrus and right insula. The MDD group had gray matter reductions in bilateral medial frontal cortex, right superior frontal gyrus, right superior temporal gyrus and bilateral cerebellums. Conclusion: The gray matter alterations of fronto-insula and fronto-temporo-cerebellum regions probably would be specific for PD and MDD respectively. In addition, the differences of gray matter volume in the fronto-temporal regions would be helpful to differentiate MDD from PD.

Many pathologies involving disc degeneration are treated with surgery and spinal implants. It is important to understand how the spine behaves mechanically as a function of disc degeneration. Shear loading is especially relevant in the natural and surgically stabilized lumbar spine. The objective of our study was to determine the effect of disc degeneration on anterior translation of the lumbar spine under shear loading. We tested 30 human cadaveric functional spinal units (L3–4 and L4–5) in anterior shear loading. First, the specimens were imaged in a 1.5 T magnetic resonance scanner. The discs were graded according to the Pfirrmann classification. The specimens were then loaded up to 250 N in anterior shear with an axial compression force of 300 N. Motion of the vertebrae was captured with an optoelectronic camera system. Inter- and intra-observer reliability for disc grading was determined (Cohen's and Fleiss' Kappa), and a non-parametric test was performed on the translation data to characterize the effect of disc degeneration on this parameter. We found fair to moderate agreement between and within observers for the disc grading. We found no significant effect of disc degeneration on anterior shear translation (Kruskal-Wallis ANOVA). Our results indicate that disc degeneration, as classified with the Pfirrmann scale, does not predict lumbar spinal motion in shear. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:450–457, 2015.

Background: Differentiating benign from malignant sinonsal lesions is essential for treatment planning as well as determining the patient′s prognosis, but the differentiation is often difficult in clinical practice. The study aimed to determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can improve the performance in differentiating benign from malignant sinonasal tumors. Methods: This retrospective study included 197 consecutive patients with sinonasal tumors (116 malignant tumors and 81 benign tumors). All patients underwent both DW and DCE-MRI in a 3-T magnetic resonance scanner. Two different settings of b values (0,700 and 0,1000 s/mm 2 ) and two different strategies of region of interest (ROI) including whole slice (WS) and partial slice (PS) were used to calculate apparent diffusion coefficients (ADCs). A DW parameter with WS ADCs b0,1000 and two DCE-MRI parameters (time intensity curve [TIC] and time to peak enhancement [Tpeak]) were finally combined to use in differentiating the benign from the malignant tumors in this study. Results: The mean ADCs of malignant sinonasal tumors (WS ADCs b0,1000 = 1.084 × 10−3 mm 2 /s) were significantly lower than those of benign tumors (WS ADCs b0,1000 = 1.617 × 10−3 mm 2 /s, P < 0.001). The accuracy using WS ADCs b0,1000 alone was 83.7% in differentiating the benign from the malignant tumors (85.3% sensitivity, 81.2% specificity, 86.4% positive predictive value [PPV], and 79.5% negative predictive value [NPV]). The accuracy using DCE with Tpeak and TIC alone was 72.1% (69.1% sensitivity, 74.1% specificity, 77.5% PPV, and 65.1% NPV). Using DW-MRI parameter was superior than using DCE parameters in differentiation between benign and malignant sinonasal tumors (P < 0.001). The accuracy was 87.3% (90.5% sensitivity, 82.7% specificity, 88.2% PPV, and 85.9% NPV) using DW-MRI combined with DCE-MRI, which was superior than that using DCE-MRI alone or using DW-MRI alone (both P < 0.001) in differentiating the benign from the malignant tumors. Conclusions: Diffusion-weighted combined with DCE-MRI can improve imaging performance in differentiating benign from malignant sinonasal tumors, which has the potential to improve diagnostic accuracy and to provide added value in the management for these tumors.