High cardiac background activity limits 99mTc-MIBI radioguided surgery in aortopulmonary window parathyroid adenomas

Background: Radioguided surgery using 99m-Technetium-methoxyisobutylisonitrile (99mTc-MIBI) has been recommended for the surgical treatment of mediastinal parathyroid adenomas. However, high myocardial 99mTc-MIBI uptake may limit the feasibility of radioguided surgery in aortopulmonary window parathyroid adenoma. Case presentation: Two female patients aged 72 (#1) and 79 years (#2) with primary hyperparathyroidism caused by parathyroid adenomas in the aortopulmonary window were operated by transsternal radioguided surgery. After intravenous injection of 370 MBq 99mTc-MIBI at start of surgery, the maximum radioactive intensity (as counts per second) was measured over several body regions using a gamma probe before and after removal of the parathyroid adenoma. Relative radioactivity was calculated in relation to the measured ex vivo radioactivity of the adenoma, which was set to 1.0. Both patients were cured by uneventful removal of aortopulmonary window parathyroid adenomas of 4400 (#1) and 985 mg (#2). Biochemical cure was documented by intraoperative measurement of parathyroid hormone as well as follow-up examination. Ex vivo radioactivity over the parathyroid adenomas was 196 (#1) and 855 counts per second (#2). Before parathyroidectomy, relative radioactivity over the aortopulmonary window versus the heart was found at 1.3 versus 2.6 (#1) and 1.8 versus 4.8 (#2). After removal of the adenomas, radioactivity within the aortopulmonary window was only slightly reduced. Conclusion: High myocardial uptake of 99mTc-MIBI limits the feasibility of radioguided surgery in aortopulmonary parathyroid adenoma.publishedVersio

The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson’s disease

We conducted a double-blinded phase I clinical trial to establish whether nicotinamide adenine dinucleotide (NAD) replenishment therapy, via oral intake of nicotinamide riboside (NR), is safe, augments cerebral NAD levels, and impacts cerebral metabolism in Parkinson’s disease (PD). Thirty newly diagnosed, treatment-naive patients received 1,000 mg NR or placebo for 30 days. NR treatment was well tolerated and led to a significant, but variable, increase in cerebral NAD levels—measured by 31phosphorous magnetic resonance spectroscopy—and related metabolites in the cerebrospinal fluid. NR recipients showing increased brain NAD levels exhibited altered cerebral metabolism, measured by 18fluoro-deoxyglucose positron emission tomography, and this was associated with mild clinical improvement. NR augmented the NAD metabolome and induced transcriptional upregulation of processes related to mitochondrial, lysosomal, and proteasomal function in blood cells and/or skeletal muscle. Furthermore, NR decreased the levels of inflammatory cytokines in serum and cerebrospinal fluid. Our findings nominate NR as a potential neuroprotective therapy for PD, warranting further investigation in larger trials.publishedVersio

High cardiac background activity limits 99mTc-MIBI radioguided surgery in aortopulmonary window parathyroid adenomas

Background: Radioguided surgery using 99m-Technetium-methoxyisobutylisonitrile (99mTc-MIBI) has been recommended for the surgical treatment of mediastinal parathyroid adenomas. However, high myocardial 99mTc-MIBI uptake may limit the feasibility of radioguided surgery in aortopulmonary window parathyroid adenoma. Case presentation: Two female patients aged 72 (#1) and 79 years (#2) with primary hyperparathyroidism caused by parathyroid adenomas in the aortopulmonary window were operated by transsternal radioguided surgery. After intravenous injection of 370 MBq 99mTc-MIBI at start of surgery, the maximum radioactive intensity (as counts per second) was measured over several body regions using a gamma probe before and after removal of the parathyroid adenoma. Relative radioactivity was calculated in relation to the measured ex vivo radioactivity of the adenoma, which was set to 1.0. Both patients were cured by uneventful removal of aortopulmonary window parathyroid adenomas of 4400 (#1) and 985 mg (#2). Biochemical cure was documented by intraoperative measurement of parathyroid hormone as well as follow-up examination. Ex vivo radioactivity over the parathyroid adenomas was 196 (#1) and 855 counts per second (#2). Before parathyroidectomy, relative radioactivity over the aortopulmonary window versus the heart was found at 1.3 versus 2.6 (#1) and 1.8 versus 4.8 (#2). After removal of the adenomas, radioactivity within the aortopulmonary window was only slightly reduced. Conclusion: High myocardial uptake of 99mTc-MIBI limits the feasibility of radioguided surgery in aortopulmonary parathyroid adenoma

A machine learning pipeline for autonomous numerical analytic continuation of Dyson-Schwinger equations

Dyson-Schwinger equations (DSEs) are a non-perturbative way to express n-point functions in quantum field theory. Working in Euclidean space and in Landau gauge, for example, one can study the quark propagator Dyson-Schwinger equation in the real and complex domain, given that a suitable and tractable truncation has been found. When aiming for solving these equations in the complex domain, that is, for complex external momenta, one has to deform the integration contour of the radial component in the complex plane of the loop momentum expressed in hyper-spherical coordinates. This has to be done in order to avoid poles and branch cuts in the integrand of the self-energy loop. Since the nature of Dyson-Schwinger equations is such, that they have to be solved in a self-consistent way, one cannot analyze the analytic properties of the integrand after every iteration step, as this would not be feasible. In these proceedings, we suggest a machine learning pipeline based on deep learning (DL) approaches to computer vision (CV), as well as deep reinforcement learning (DRL), that could solve this problem autonomously by detecting poles and branch cuts in the numerical integrand after every iteration step and by suggesting suitable integration contour deformations that avoid these obstructions. We sketch out a proof of principle for both of these tasks, that is, the pole and branch cut detection, as well as the contour deformation

Evaluation of a new e-learning framework for teaching nuclear medicine and radiology to undergraduate medical students

Background: Radiology and nuclear medicine have traditionally been taught in a series of lectures and seminars concluded by an examination testing knowledge rather than skills. Purpose: To emphasize skills in the students’ learning process, we developed and evaluated a new e-learning framework for teaching medical imaging. Material and Methods: The framework consists of electronic lectures, a learning management system (LMS), and a diagnostic viewing system. Students were to review positron emission tomography/computed tomography (PET/CT) examinations of five cases of lung cancer. The framework was evaluated in an objective structured clinical examination (OSCE) taken by 139 undergraduate students at the end of their third year, and in a comparative survey of two groups of 85 and 84 students in the fifth and sixth year who were taught the same oncology course with and without mandatory PET/CT exercises, respectively. Results: Of the 139 third-year students, 134 (96%) passed the OSCE PET/CT station according to the predefined criteria. While 85/85 (100%) of the fifth-year students had taken exercises when they were mandatory, only 2/84 (2%) of the sixth-year students had reviewed the cases on a voluntary basis (P < 0.001). Of the 25 survey responders in the fifth year, 24 (96%) agreed that the mandatory PET/CT exercises had promoted their learning while the sixth-year students, whose course concluded with a multiple-choice examination, emphasized the utility of online lectures. Conclusion: The new e-learning framework teaches students basic competency in PET/CT navigation and interpretation and is associated with a high degree of student satisfaction

Combined variants in reading epilepsy; coexisting anterior and posterior variants camouflaged as heat cramps where the patient finds his own diagnosis searching the internet

Reading epilepsy is a form of reflex-induced seizures. Two entities are postulated as part of a clinical spectrum; one anterior variant with jaw jerks and orofacial myoclonia and another posterior variant with visual symptoms and alexia or dyslexia. We present a case with suggestible evidence of both conditions coexisting within the same patient, a finding that, to our knowledge, has not been previously reported. The diagnosis in this specific case was contributed to by the patient searching the internet

Quantitative and clinical impact of MRI-based attenuation correction methods in[18F]FDG evaluation of dementia

Background Positron emission tomography/magnetic resonance imaging (PET/MRI) is a promising diagnostic imaging tool for the diagnosis of dementia, as PET can add complementary information to the routine imaging examination with MRI. The purpose of this study was to evaluate the influence of MRI-based attenuation correction (MRAC) on diagnostic assessment of dementia with [18F]FDG PET. Quantitative differences in both [18F]FDG uptake and z-scores were calculated for three clinically available (DixonNoBone, DixonBone, UTE) and two research MRAC methods (UCL, DeepUTE) compared to CT-based AC (CTAC). Furthermore, diagnoses based on visual evaluations were made by three nuclear medicine physicians and one neuroradiologist (PETCT, PETDeepUTE, PETDixonBone, PETUTE, PETCT + MRI, PETDixonBone + MRI). In addition, pons and cerebellum were compared as reference regions for normalization. Results The mean absolute difference in z-scores were smallest between MRAC and CTAC with cerebellum as reference region: 0.15 ± 0.11 σ (DeepUTE), 0.15 ± 0.12 σ (UCL), 0.23 ± 0.20 σ (DixonBone), 0.32 ± 0.28 σ (DixonNoBone), and 0.54 ± 0.40 σ (UTE). In the visual evaluation, the diagnoses agreed with PETCT in 74% (PETDeepUTE), 67% (PETDixonBone), and 70% (PETUTE) of the patients, while PETCT + MRI agreed with PETDixonBone + MRI in 89% of the patients. Conclusion The MRAC research methods performed close to that of CTAC in the quantitative evaluation of [18F]FDG uptake and z-scores. Among the clinically implemented MRAC methods, DixonBone should be preferred for diagnostic assessment of dementia with [18F]FDG PET/MRI. However, as artifacts occur in DixonBone attenuation maps, they must be visually inspected to assure proper quantification

Default-mode network functional connectivity is closely related to metabolic activity

Over the last decade, the brain's default-mode network (DMN) and its function has attracted a lot of attention in the field of neuroscience. However, the exact underlying mechanisms of DMN functional connectivity, or more specifically, the blood-oxygen level-dependent (BOLD) signal, are still incompletely understood. In the present study, we combined 2-deoxy-2-[18F]fluoroglucose positron emission tomography (FDG-PET), proton magnetic resonance spectroscopy (1H-MRS), and resting-state functional magnetic resonance imaging (rs-fMRI) to investigate more directly the association between local glucose consumption, local glutamatergic neurotransmission and DMN functional connectivity during rest. The results of the correlation analyzes using the dorsal posterior cingulate cortex (dPCC) as seed region showed spatial similarities between fluctuations in FDG-uptake and fluctuations in BOLD signal. More specifically, in both modalities the same DMN areas in the inferior parietal lobe, angular gyrus, precuneus, middle, and medial frontal gyrus were positively correlated with the dPCC. Furthermore, we could demonstrate that local glucose consumption in the medial frontal gyrus, PCC and left angular gyrus was associated with functional connectivity within the DMN. We did not, however, find a relationship between glutamatergic neurotransmission and functional connectivity. In line with very recent findings, our results lend further support for a close association between local metabolic activity and functional connectivity and provide further insights towards a better understanding of the underlying mechanism of the BOLD signal

Excellent response of intramedullary Erdheim-Chester disease to vemurafenib: a case report

Background: Erdheim-Chester disease is a rare histiocytosis characterized by multi-systemic organ involvement. Immune-modulating agents such as interferon-alpha have limited success and the disorder is progressive and causes high morbidity and mortality. Treatment with the BRAF-inhibitor vemurafenib has recently produced substantial improvement in three patients with Erdheim-Chester disease expressing the p. V600E BRAF mutation. The disorder commonly affects the central nervous system and it is not yet known whether vemurafenib can reverse intra-axial infiltration and the resulting neurological impairment. Case presentation: In this work, we report for the first time an excellent clinical response to vemurafenib in a Norwegian patient with debilitating progressive spastic paraparesis due to intra-axial infiltration of the thoracic spinal cord. The patient had been unresponsive to interferon-alpha. Low dose vemurafenib (720 mg daily) for a period of three months resulted in significant tumor shrinkage by >60% and regression of contrast enhancement and fluorodeoxyglucose uptake on positron-emission tomography. The patient’s spastic paraparesis and gait function improved dramatically. She currently walks unaided and reports a substantially improved quality of life. Conclusion: Our findings show that vemurafenib therapy, even at low doses, can be effective for the treatment of intra-axial central nervous system involvement in BRAF-positive Erdheim-Chester disease

Progressive striatal necrosis associated with anti-NMDA receptor antibodies

Background: We report a case of childhood onset, generalized dystonia due to slowly progressive bilateral striatal necrosis associated with anti-N-methyl-D-aspartate receptor (NMDAR) antibodies. This clinical phenotype has not been previously associated with NMDA receptor autoimmunity. Case presentation: An eighteen year old man presented with a history of childhood-onset, progressive generalized dystonia. Clinical examination revealed a pure generalized dystonia with no cognitive or other neurological findings. Magnetic resonance imaging showed bilateral high T2 signal striatal lesions, which were slowly progressive over a period of nine years. New parts of the lesion showed restricted water diffusion suggesting cytotoxic oedema. Positron emission tomography of the brain showed frontal hypermetabolism and cerebellar hypometabolism. Antibodies against the NR1 subunit of the NMDA receptor were detected in the patient’s serum and cerebrospinal fluid. There was no neoplasia or preceding infection or vaccination. Conclusion: This is the first report of chronic progressive bilateral striatal necrosis associated with anti-NMDAR antibodies. Our findings expand the clinical spectrum of disease associated with anti-NMDAR antibodies and suggest that these should be included in the work-up of dystonia with striatal necrosis