The purpose of this study was to present the prebolus technique for quantitative multislice myocardial perfusion imaging. In quantitative MR perfusion studies the maximum contrast agent dose is limited by the requirement to determine the arterial input function (AIF). The prebolus technique consists of two consecutive contrast agent administrations. The AIF is determined from a first low-dose bolus, while a second, high-dose bolus allows the measurement of the myocardium with improved signal increase. The results of the prebolus technique using a multislice saturation recovery trueFISP sequence in healthy volunteers are presented. In comparison to a standard dose of 3 ml Gd-DTPA, perfusion values are maintained while the signal increase in the concentration time courses was considerably improved, accompanied by reduced standard deviations of the obtained perfusion values (0.72 ؎ 0.13 ml/g/min for 1 ml/8 ml and 0.67 ؎ 0.10 ml/g/min for 1 ml/12 ml Gd-DTPA, respectively The clinical practicability of first-pass contrast-enhanced myocardial perfusion MRI has been improved in the last years by a number of technical changes of the acquisition sequences (1). Consequently, clinical first-pass perfusion studies could be performed for the primary diagnosis of coronary artery disease, as well as for the detection of myocardial viability (2,3). Different strategies to determine quantitative values of myocardial perfusion in humans have been proposed (4 -9) and normal values for healthy human volunteers have been reported (5-9). A prerequisite for perfusion quantification is the determination of the arterial input function (AIF). But saturation effects allow the determination of the AIF only for low concentrations of contrast agent (10), while a high dose leads to improved signal-to-noise ratio (SNR) in the myocardium (11). The combination of the advantages of both doses has been shown in an animal study (12). In this work the prebolus technique was applied to humans. A multislice version using a saturation recovery technique was implemented for quantitative measurement of myocardial perfusion in healthy volunteers. MATERIALS AND METHODS In Vivo Perfusion ImagingThis study was approved by our institution's Ethics Committee and written informed consent was obtained from all 11 volunteers (eight male, three female, age 24 Ϯ 4 years). All measurements were carried out on a clinical 1.5 T whole-body scanner (Magnetom Symphony, Siemens Medical Solutions, Erlangen, Germany) using a 12-element body phased array coil. First-pass perfusion images were acquired with an arrhythmia-insensitive multislice, saturation recovery trueFISP imaging technique (13). The following sequence parameters were chosen: repetition time 2.6 ms, echo time 1.1 ms, delay between saturation and sampling of center of k-space 110 ms, flip angle 50°, threequarters Fourier acquisition, number of phase encoding lines 60, FOV 340 mm with reduction to 3/4, i.e., 255 mm, in phase-encoding direction, slice thickness 8 mm. Forty consecutive images were acquired for ea...

Background Autoimmune-mediated encephalitis is a disease that often encompasses psychiatric symptoms as its first clinical manifestation’s predominant and isolated characteristic. Novel guidelines even distinguish autoimmune psychosis from autoimmune encephalitis. The aim of this review is thus to explore whether a wide range of psychiatric symptoms and syndromes are associated or correlate with autoantibodies. Methods We conducted a PubMed search to identify appropriate articles concerning serum and/or cerebrospinal fluid (CSF) autoantibodies associated with psychiatric symptoms and syndromes between 2000 and 2020. Relying on this data, we developed a diagnostic approach to optimize the detection of autoantibodies in psychiatric patients, potentially leading to the approval of an immunotherapy. Results We detected 10 major psychiatric symptoms and syndromes often reported to be associated with serum and/or CSF autoantibodies comprising altered consciousness, disorientation, memory impairment, obsessive-compulsive behavior, psychosis, catatonia, mood dysfunction, anxiety, behavioral abnormalities (autism, hyperkinetic), and sleeping dysfunction. The following psychiatric diagnoses were associated with serum and/or CSF autoantibodies: psychosis and schizophrenia spectrum disorders, mood disorders, minor and major neurocognitive impairment, obsessive-compulsive disorder, autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), anxiety disorders, eating disorders and addiction. By relying on these symptom clusters and diagnoses in terms of onset and their duration, we classified a subacute or subchronic psychiatric syndrome in patients that should be screened for autoantibodies. We propose further diagnostics entailing CSF analysis, electroencephalography and magnetic resonance imaging of the brain. Exploiting these technologies enables standardized and accurate diagnosis of autoantibody-associated psychiatric symptoms and syndromes to deliver early immunotherapy. Conclusions We have developed a clinical diagnostic pathway for classifying subgroups of psychiatric patients whose psychiatric symptoms indicate a suspected autoimmune origin.

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