Mild Deficits in Fear Learning: Evidence from Humans and Mice with Cerebellar Cortical Degeneration.

Functional brain imaging studies in humans suggest involvement of the cerebellum in fear conditioning but do not allow conclusions about the functional significance. The main aim of the present study was to examine whether patients with cerebellar degeneration show impaired fear conditioning and whether this is accompanied by alterations in cerebellar cortical activations. To this end, a 2 d differential fear conditioning study was conducted in 20 cerebellar patients and 21 control subjects using a 7 tesla (7 T) MRI system.

Central intra-lesional iron deposits as a possible novel imaging marker at 7 Tesla MRI in Susac Syndrome - an exploratory study.

Background: Susac syndrome (SuS) is a rare autoimmune disease that leads to hearing impairment, visual field deficits, and encephalopathy due to an occlusion of precapillary arterioles in the brain, retina, and inner ear. Given the potentially disastrous outcome and difficulties in distinguishing SuS from its differential diagnoses, such as multiple sclerosis (MS), our exploratory study aimed at identifying potential new SuS-specific neuroimaging markers.

Methods: Seven patients with a definite diagnosis of SuS underwent magnetic resonance imaging (MRI) at 7 Tesla (7T), including T2* weighted and quantitative susceptibility mapping (QSM) sequences.

The Potential of Iron Oxide Nanoparticle-Enhanced MRI at 7 T Compared With 3 T for Detecting Small Suspicious Lymph Nodes in Patients With Prostate Cancer.

Background: Accurate detection of lymph node (LN) metastases in prostate cancer (PCa) is a challenging but crucial step for disease staging. Ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI) enables distinction between healthy LNs and nodes suspicious for harboring metastases. When combined with MRI at an ultra-high magnetic field, an unprecedented spatial resolution can be exploited to visualize these LNs.

Prediction of therapy response of breast cancer patients with machine learning based on clinical data and imaging data derived from breast [F]FDG-PET/MRI.

Purpose: To evaluate if a machine learning prediction model based on clinical and easily assessable imaging features derived from baseline breast [F]FDG-PET/MRI staging can predict pathologic complete response (pCR) in patients with newly diagnosed breast cancer prior to neoadjuvant system therapy (NAST).

Methods: Altogether 143 women with newly diagnosed breast cancer (54 ± 12 years) were retrospectively enrolled. All women underwent a breast [F]FDG-PET/MRI, a histopathological workup of their breast cancer lesions and evaluation of clinical data.

Systematic evaluation of human soft tissue attenuation correction in whole-body PET/MR: Implications from PET/CT for optimization of MR-based AC in patients with normal lung tissue.

Background: Attenuation correction (AC) is an important methodical step in positron emission tomography/magnetic resonance imaging (PET/MRI) to correct for attenuated and scattered PET photons.

Purpose: The overall quality of magnetic resonance (MR)-based AC in whole-body PET/MRI was evaluated in direct comparison to computed tomography (CT)-based AC serving as reference. The quantitative impact of isolated tissue classes in the MR-AC was systematically investigated to identify potential optimization needs and strategies.

Recurrent prostate cancer: combined role for MRI and PSMA-PET in Ga-PSMA-11 PET/MRI.

Objectives: To investigate the specific strengths of MRI and PET components in Ga-PSMA-11 PET/MRI for staging of patients with biochemically recurrent prostate cancer (PCa).

Methods: Patients with biochemical recurrence of PCa and contrast-enhanced whole-body Ga-PSMA-11 PET/MRI including a dedicated pelvic multiparametric MRI were included in this retrospective study. Imaging datasets of MRI and PET were evaluated separately regarding local PCa recurrence (Tr), pelvic lymph node metastases (N1), distant lymph node metastases (M1a), bone metastases (M1b), and soft tissue metastases (M1c) according to PROMISE version 1.

Safety and function of programmable ventriculo-peritoneal shunt valves: An in vitro 7 Tesla magnetic resonance imaging study.

Objective: The quantity of ultra-high field MRI neuroimaging studies has rapidly increased. This study tests function, safety, and image artifacts of two frequently implanted programmable ventriculo-peritoneal (VP) shunt valves in a 7T MRI system.

Methods: All tests were performed using a whole-body 7T MRI system.

International EANM-SNMMI-ISMRM consensus recommendation for PET/MRI in oncology.

The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM) is a professional non-profit medical association that facilitates communication worldwide between individuals pursuing clinical and research excellence in nuclear medicine. The EANM was founded in 1985.

[F]FDG PET/MRI in children suffering from lymphoma: does MRI contrast media make a difference?

Objectives: Evaluate the influence of an MRI contrast agent application on primary and follow-up staging in pediatric patients with newly diagnosed lymphoma using [F]FDG PET/MRI to avoid adverse effects and save time and costs during examination.

Methods: A total of 105 [F]FDG PET/MRI datasets were included for data evaluation. Two different reading protocols were analyzed by two experienced readers in consensus, including for PET/MRI-1 reading protocol unenhanced T2w and/or T1w imaging, diffusion-weighted imaging (DWI), and [F]FDG PET imaging and for PET/MRI-2 reading protocol an additional T1w post contrast imaging.

Towards a fast PET/MRI protocol for breast cancer imaging: maintaining diagnostic confidence while reducing PET and MRI acquisition times.

Objectives: To investigate the diagnostic feasibility of a shortened breast PET/MRI protocol in breast cancer patients.

Methods: Altogether 90 women with newly diagnosed T1 (T1) and T2 (T2) breast cancer were included in this retrospective study. All underwent a dedicated comprehensive breast [F]FDG-PET/MRI.

Germany's journey toward 14 Tesla human magnetic resonance.

Multiple sites within Germany operate human MRI systems with magnetic fields either at 7 Tesla or 9.4 Tesla. In 2013, these sites formed a network to facilitate and harmonize the research being conducted at the different sites and make this technology available to a larger community of researchers and clinicians not only within Germany, but also worldwide.

Correlation between Imaging Markers Derived from PET/MRI and Invasive Acquired Biomarkers in Newly Diagnosed Breast Cancer.

Purpose: Evaluate the diagnostic potential of [F]FDG-PET/MRI data compared with invasive acquired biomarkers in newly diagnosed early breast cancer (BC).

Methods: Altogether 169 women with newly diagnosed BC were included. All underwent a breast- and whole-body [F]FDG-PET/MRI for initial staging.

Numerical approach to investigate MR imaging artifacts from orthopedic implants at different field strengths according to ASTM F2119.

Objective: This study presents an extended evaluation of a numerical approach to simulate artifacts of metallic implants in an MR environment.

Methods: The numerical approach is validated by comparing the artifact shape of the simulations and measurements of two metallic orthopedic implants at three different field strengths (1.5 T, 3 T, and 7 T).

Grad-CAM Guided U-Net for MRI-based Pseudo-CT Synthesis.

In this paper, we address the task of image-to-image translation from MRI to CT domain. We propose a 2D U-Net-based deep learning approach for pseudo-CT synthesis that incorporates an additional Grad-CAM guided attention mechanism for superior image translation of bone regions. The suggested architecture consists of image-to-image translation and image classification modules.

Lung Nodules Missed in Initial Staging of Breast Cancer Patients in PET/MRI-Clinically Relevant?

Purpose: The evaluation of the clinical relevance of missed lung nodules at initial staging of breast cancer patients in [F]FDG-PET/MRI compared with CT.

Methods: A total of 152 patients underwent an initial whole-body [F]FDG-PET/MRI and a thoracoabdominal CT for staging. Presence, size, shape and location for each lung nodule in [F]FDG-PET/MRI was noted.

Intra-Individual Comparison of I-PET/CT and I-PET/MR Hybrid Imaging of Patients with Resected Differentiated Thyroid Carcinoma: Aspects of Attenuation Correction.

Background: This study evaluates the quantitative differences between 124-iodine (I) positron emission tomography/computed tomography (PET/CT) and PET/magnetic resonance imaging (PET/MR) in patients with resected differentiated thyroid carcinoma (DTC).

Methods: = 43 I PET/CT and PET/MR exams were included. CT-based attenuation correction (AC) in PET/CT and MR-based AC in PET/MR with bone atlas were compared concerning bone AC in the head-neck region.

Multiparametric F-FDG PET/MRI-Based Radiomics for Prediction of Pathological Complete Response to Neoadjuvant Chemotherapy in Breast Cancer.

Background: The aim of this study was to assess whether multiparametric F-FDG PET/MRI-based radiomics analysis is able to predict pathological complete response in breast cancer patients and hence potentially enhance pretherapeutic patient stratification.

Methods: A total of 73 female patients (mean age 49 years; range 27-77 years) with newly diagnosed, therapy-naive breast cancer underwent simultaneous F-FDG PET/MRI and were included in this retrospective study. All PET/MRI datasets were imported to dedicated software (ITK-SNAP v.

Temporal dynamics of fMRI signal changes during conditioned interoceptive pain-related fear and safety acquisition and extinction.

Associative learning and memory mechanisms drive interoceptive signaling along the gut-brain axis, thus shaping affective-emotional reactions and behavior. Specifically, learning to predict potentially harmful, visceral pain is assumed to succeed within very few trials. However, the temporal dynamics of cerebellar and cerebral fMRI signal changes underlying early acquisition and extinction of learned fear signals and the concomitant evolvement of safety learning remain incompletely understood.

The cerebellum contributes to context-effects during fear extinction learning: A 7T fMRI study.

The cerebellum is involved in the acquisition and consolidation of learned fear responses. Knowledge about its contribution to extinction learning, however, is sparse. Extinction processes likely involve erasure of memories, but there is ample evidence that at least part of the original memory remains.

Correlation Between Thrombus Signal Intensity and Aneurysm Wall Thickness in Partially Thrombosed Intracranial Aneurysms Using 7T Magnetization-Prepared Rapid Acquisition Gradient Echo Magnetic Resonance Imaging.

Objective: The objective of this study is to investigate the relationship between the thrombus signal intensity and aneurysm wall thickness in partially thrombosed intracranial aneurysms with magnetization-prepared rapid acquisition gradient echo (MPRAGE) taken using 7T magnetic resonance imaging (MRI) and correlate the findings to wall instability.

Methods: Sixteen partially thrombosed intracranial aneurysms were evaluated using a 7T whole-body MR system with nonenhanced MPRAGE. To normalize the thrombus signal intensity, its highest signal intensity was compared to that of the anterior corpus callosum of the same subject, and the signal intensity ratio was calculated.

Evaluation of improved CT-based hardware attenuation correction in PET/MRI: Application to a 16-channel RF breast coil.

Purpose: The aim of this study was to compare and evaluate three different bilinear conversion curves for attenuation correction (AC) of a 16-channel radiofrequency (RF) coil in positron emission tomography/magnetic resonance (PET/MR) breast cancer imaging.

Methods: The quantitative impact of three different bilinear conversions of computed tomography (CT) data for the AC of a 16-channel RF breast coil was systematically evaluated in phantom measurements and on n = 20 PET/MR patients with breast cancer. PET data were reconstructed four times: (1) no coil AC (C-NAC) serving as a reference, (2) established bilinear conversion by Carney et al.

MR-based truncation correction using an advanced HUGE method to improve attenuation correction in PET/MR imaging of obese patients.

Purpose: Truncation artifacts in the periphery of the magnetic resonance (MR) field-of-view (FOV) and thus, in the MR-based attenuation correction (AC) map, may hamper accurate positron emission tomography (PET) quantification in whole-body PET/MR, which is especially problematic in patients with obesity with overall large body dimensions. Therefore, an advanced truncation correction (TC) method to extend the conventional MR FOV is needed.

Methods: The extent of MR-based AC-map truncations in obese patients was determined in a dataset including n  =  10 patients that underwent whole-body PET/MR exams.

Performance and safety assessment of an integrated transmit array for body imaging at 7 T under consideration of specific absorption rate, tissue temperature, and thermal dose.

In this study, the performance of an integrated body-imaging array for 7 T with 32 radiofrequency (RF) channels under consideration of local specific absorption rate (SAR), tissue temperature, and thermal dose limits was evaluated and the imaging performance was compared with a clinical 3 T body coil. Thirty-two transmit elements were placed in three rings between the bore liner and RF shield of the gradient coil. Slice-selective RF pulse optimizations for B shimming and spokes were performed for differently oriented slices in the body under consideration of realistic constraints for power and local SAR.