Psychosomatically Oriented Diagnostics and Therapy for Fertility Disorders. Guideline of the DGPFG (S2k-Level, AWMF Registry Number 016/003, December 2019).

Aim The purpose of this official guideline published and coordinated by the German Society for Psychosomatic Gynecology and Obstetrics [Deutsche Gesellschaft für Psychosomatische Frauenheilkunde und Geburtshilfe (DGPFG)] is to provide a consensus-based overview of psychosomatically oriented diagnostic procedures and treatments for fertility disorders by evaluating the relevant literature. Method This S2k guideline was developed using a structured consensus process which included representative members of various professions; the guideline was commissioned by the DGPFG and is based on the 2014 version of the guideline. Recommendations The guideline provides recommendations on psychosomatically oriented diagnostic procedures and treatments for fertility disorders.

Augmented Whole-Body Scanning via Magnifying PET.

A novel technique, called augmented whole-body scanning via magnifying PET (AWSM-PET), that improves the sensitivity and lesion detectability of a PET scanner for whole-body imaging is proposed and evaluated. A Siemens Biograph Vision PET/CT scanner equipped with one or two high-resolution panel-detectors was simulated to study the effectiveness of AWSM-PET technology. The detector panels are located immediately outside the scanner's axial field-of-view (FOV). A detector panel contains 2 ×8 detector modules each consisting of 32 ×64 LSO crystals ( 1.0 ×1.0 ×10.0 mm3 each). A 22Na point source was stepped across the scanner's FOV axially to measure sensitivity profiles at different locations. An elliptical torso phantom containing 7×9 spherical lesions was imaged at different axial locations to mimic a multi-bed-position whole-body imaging protocol. Receiver operating characteristic (ROC) curves were analyzed to evaluate the improvement in lesion detectability by the AWSM-PET technology. Experimental validation was conducted using an existing flat-panel detector integrated with a Siemens Biograph 40 PET/CT scanner to image a torso phantom containing spherical lesions with diameters ranging from 3.3 to 11.4 mm. The contrast-recovery-coefficient (CRC) of the lesions was evaluated for the scanner with or without the AWSM-PET technology. Monte Carlo simulation shows 36%-42% improvement in system sensitivity by a dual-panel AWSM-PET device. The area under the ROC curve is 0.962 by a native scanner for the detection of 4 mm diameter lesions with 5:1 tumor-to-background activity concentration. It was improved to 0.977 and 0.991 with a single- and dual-panel AWSM-PET system, respectively. Experimental studies showed that the average CRC of 3.3 mm and 4.3 mm diameter tumors were improved from 2.8% and 4.2% to 7.9% and 11.0%, respectively, by a single-panel AWSM-PET device. With a high-sensitivity dual-panel device, the corresponding CRC can be further improved to 11.0% and 15.9%, respectively. The principle of the AWSM-PET technology has been developed and validated. Enhanced system sensitivity, CRC and tumor detectability were demonstrated by Monte Carlo simulations and imaging experiments. This technology may offer a cost-effective path to realize high-resolution whole-body PET imaging clinically.

Fighter, Corpsman, Partisan an Attempt to Typify Former Soldiers Based on their Coping and Defense Mechanisms.

This work strives to develop a typological classification of the use of conscious and unconscious defense and coping mechanisms based on methodically and structurally collected data from a qualitative survey of 43 former soldiers in Germany. Seven coping and defense types were identified: the Fighter, the Comrade, the Corpsman, the Strategist, the Partisan, the Self-Protector and the Infantryman. The types identified differed with regard to the accumulation, combination, and use of their conscious and unconscious defense and coping mechanisms in the superordinate areas of behaviour, relationships, emotions, reflexivity and time focus. The typological classification could offer psychotherapeutic interventions tailored to individuals and their defense and coping mechanisms, which could lead to improved therapy use and compliance.

A second-generation virtual-pinhole PET device for enhancing contrast recovery and improving lesion detectability of a whole-body PET/CT scanner.

PURPOSE: We have developed a second-generation virtual-pinhole (VP) positron emission tomography (PET) device that can position a flat-panel PET detector around a patient's body using a robotic arm to enhance the contrast recovery coefficient (CRC) and detectability of lesions in any region-of-interest using a whole-body PET/computed tomography (CT) scanner. METHODS: We constructed a flat-panel VP-PET device using 32 high-resolution detectors, each containing a 4  ×  4 MPPC array and 16  ×  16 LYSO crystals of 1.0  ×  1.0  ×  3.0 mm3 each. The flat-panel detectors can be positioned around a patient's body anywhere in the imaging field-of-view (FOV) of a Siemens Biograph 40 PET/CT scanner by a robotic arm. New hardware, firmware and software have been developed to support the additional detector signals without compromising a scanner's native functions. We stepped a 22 Na point source across the axial FOV of the scanner to measure the sensitivity profile of the VP-PET device. We also recorded the coincidence events measured by the scanner detectors and by the VP-PET detectors when imaging phantoms of different sizes. To assess the improvement in the CRC of small lesions, we imaged an elliptical torso phantom measuring 316  ×  228  ×  162 mm3 that contains spherical tumors with diameters ranging from 3.3 to 11.4 mm with and without the VP-PET device. Images were reconstructed using a list mode Maximum-Likelihood Estimation-Maximization algorithm implemented on multiple graphics processing units (GPUs) to support the unconventional geometries enabled by a VP-PET system. The mean and standard deviation of the CRC were calculated for tumors of different sizes. Monte Carlo simulation was also conducted to image clusters of lesions in a torso phantom using a PET/CT scanner alone or the same scanner equipped with VP-PET devices. Receiver operating characteristic (ROC) curves were analyzed for three system configurations to evaluate the improvement in lesion detectability by the VP-PET device over the native PET/CT scanner. RESULTS: The repeatability in positioning the flat-panel detectors using a robotic arm is better than 0.15 mm in all three directions. Experimental results show that the average CRC of 3.3, 4.3, and 6.0 mm diameter tumors was 0.82%, 2.90%, and 5.25%, respectively, when measured by the native scanner. The corresponding CRC was 2.73%, 6.21% and 10.13% when imaged by the VP-PET insert device with the flat-panel detector under the torso phantom. These values may be further improved to 4.31%, 9.65% and 18.01% by a future dual-panel VP-PET insert device if DOI detectors are employed to triple its detector efficiency. Monte Carlo simulation results show that the tumor detectability can be improved by a VP-PET device that has a single flat-panel detector. The improvement is greater if the VP-PET device employs a dual-panel design. CONCLUSIONS: We have developed a prototype flat-panel VP-PET device and integrated it with a clinical PET/CT scanner. It significantly enhances the contrast of lesions, especially for those that are borderline detectable by the native scanner, within regions-of-interest specified by users. Simulation demonstrated the enhancement in lesion detectability with the VP-PET device. This technology may become a cost-effective solution for organ-specific imaging tasks.

[Mental Health Stigma: An Influencing Factor in Healthcare Utilization by Veterans of the German Armed Forces]. / "Treffer im Kopf" ­ Stigma psychischer Erkrankungen als Einflussfaktor auf die Inanspruchnahme von Hilfsangeboten durch VeteranInnen der Bundeswehr.

THEORETICAL BACKGROUND AND OBJECTIVE OF THE STUDY: Mental illness stigma is a barrier to healthcare utilization. This study is the first to research the connection between mental illness stigma and the use of healthcare by veterans of the German Armed Forces. An overview of perceived stigma components in this sample is provided that should help understand how these factors influence healthcare utilization. METHODS: 43 interviews with veterans of the German Armed Forces were conducted. The resulting data were analyzed in several coding steps. It was investigated whether the stigma experience of veterans of the German Armed Forces could be well illustrated by the theory-based stigmatization model of Link and Phelan. A set of hypotheses on stigma and healthcare utilization based on the data were developed. RESULTS: All stigma components according to the model of Link and Phelan were found in the sample. Internalized stigma, perceived public stigmatization, vocational disadvantage and social exclusion as well as feared misunderstanding of the military past in the civilian sector were reported as main stigma-relevant barriers to the use of healthcare. CONCLUSIONS: Recommendations for interventions are given to decrease mental illness stigma in this specific group of former soldiers.

Stigma and its impact on the families of former soldiers of the German Armed Forces: an exploratory study.

BACKGROUND: Military families who have a family member with a mental illness see themselves confronted with many demands. Stigmatization is one of these challenges. Stigmatization affects not only the individual who suffers from a mental illness but also other family members via stigma by association and vicarious stigma. Stigma by association occurs when mental illness stigma spills over to individuals associated with an individual with a mental illness. Vicarious stigma describes the suffering of family members when they note the impact of stigma on their relative with mental illness. As a societal phenomenon, stigma plays out in social interactions and might therefore influence the social networks of families. It is also associated with healthcare utilization. METHOD: Narrative interviews were conducted with 15 family members (partners, spouses, parents and children) of former soldiers of the German Armed Forces with a service-induced mental illness. The transcribed interview data were analyzed using a thematic analysis approach, in which codes were formed and emerging themes were systemized. Relationships between stigma, the families' reactions to it, its effects on their social relationships and its interference with their healthcare utilization were analyzed. RESULTS: This study provides a detailed description of how relatives of former German soldiers with mental health problems experience stigma by association and vicarious stigma. Their perceptions are shown in a model that describes stigma-related attitudes, reactions to them and their effects on the social relationships of former soldiers' families. These families felt stigmatized because of the former soldiers' mental illness (mental illness stigma) and the military context in which it occurred (former soldier stigma). They reacted with nondisclosure, anger, acceptance and self-blame. Stigma was associated with smaller and weaker social networks that were characterized by social exclusion, self-segregation and conflicts with extended family, friends and colleagues. Stigma also affected the families' healthcare utilization. CONCLUSIONS: Urgently needed anti-stigma campaigns, particularly in the civilian context, should address the stigmatization of both mental illness and the military participation of the families affected. They should consider the needs of both former soldiers with a mental illness and their families.

Understanding health care avoidance and initial help-seeking behavior in German veterans: a theory of planned behavior.

OBJECTIVE: To gain initial insights into salient beliefs of former German soldiers (veterans) about the use of mental health services. DATA SOURCE: Narrative interviews with former German soldiers (veterans) were conducted in 2016. DATA COLLECTION/EXTRACTION METHOD: Forty-three interviews were transcribed and analyzed thematically based on the theoretical framework of the theory of planned behavior. From within the behavorial, normative, and control beliefs, the salient beliefs were identified. PRINCIPAL FINDINGS: Four groups of salient beliefs were identified, described, and named: "Autarky", "Ineffectiveness", "Heteronomy", and "Incapacity". CONCLUSION: Interventions and campaigns addressing these four specific groups of beliefs may lead to higher health service use rates. However, as a result of methodological limitations of the study design, the conclusion remains tentative.

[Barriers to treatment-seeking among German veterans: expert interviews]. / Barrieren der Inanspruchnahme von Psychotherapie ehemaliger Soldatinnen und Soldaten der Bundeswehr (Veteranen). Eine Expertenbefragung.

BACKGROUND: The number of service members of the German armed forces suffering from deployment-related mental health problems is increasing. However, less than 50 % seek professional help, and there is little knowledge about the barriers to treatment-seeking. METHODS: The article presents data gathered by the Delphi technique combined with focus groups from 55 health service experts regarding the evaluated barriers to treatment-seeking among German veterans. FINDINGS: According to the interviewed experts, major contextual barriers to treatment-seeking include: 1) intimidating processes and structures, 2) actual stigmatization and discrimination, and 3) health service deficits. Major individual barriers to treatment were: 4) health beliefs, self-perception and fear of stigmatization, and 5) avoidance behavior related to psychopathology. In addition, there is another both contextual and individual barrier, i.e., 6) information deficits. INTERPRETATION: Individual internal factors like the soldiers' self-perception and their fear of being stigmatized were considered important barriers to treatment-seeking. The experts' opinion about avoidance behavior related to psychopathology and deficits in health services and information coincides with international findings. Compared to research in other countries, actual stigmatization and discrimination were regarded to be an important barrier in itself. According to our findings daunting/intimidating processes and structures like time-consuming and complex expert medical reports rather seem to be a German phenomenon.

Multiscale Analysis of Mineralized Collagen Combining X-ray Scattering and Fluorescence with Raman Spectroscopy under Controlled Mechanical, Thermal, and Humidity Environments.

Biological materials, such as mineralized collagen, are structured over many length scales. This represents a challenge for quantitative characterization, in particular when complex specimen environments are required. This paper describes an approach based on synchrotron X-ray scattering and Raman spectroscopy to analyze the structure of biological materials from the molecular to the macroscopic range in controlled environments including humidity, temperature, and mechanical load. This is achieved by a new setup, installed at the microfocus beamline µSpot at the BESSY II synchrotron in Berlin, where a perforated mirror is placed into the X-ray beam to focus laser light into the specimen to excite a Raman signal. We show that this allows simultaneous micrometer-scale mapping of chemical groups in the organic matrix together with the size and orientation of mineral nanoparticles in mineralized collagen. The approach is especially suitable to studying time-dependent modifications of materials, such as molecular changes during tensile deformation, dehydration, or thermal denaturation.

Is trait resilience characterized by specific patterns of attentional bias to emotional stimuli and attentional control?

BACKGROUND AND OBJECTIVES: Attentional processes have been suggested to play a crucial role in resilience defined as positive adaptation facing adversity. However, research is lacking on associations between attentional biases to positive and threat-related stimuli, attentional control and trait resilience. METHODS: Data stem from the follow-up assessment of a longitudinal study investigating mental health and related factors among German soldiers. Trait resilience was assessed with the Connor-Davidson Resilience Scale and attentional control with the Attentional Control Scale. A subset of n = 198 soldiers also completed a dot probe task with happy, neutral and threatening faces. RESULTS: Attentional control was positively related to trait resilience. Results revealed no associations between both attentional biases and trait resilience. However, there was a negative association between attentional bias to threat and trait resilience when attentional control was low and a positive association between attentional bias to threat and trait resilience when attentional control was high. No such associations were found for attentional bias to positive stimuli. LIMITATIONS: Generalizability to other populations may be limited since we exclusively focused on male soldiers. Also, the cross-sectional design does not allow for causal conclusions. CONCLUSIONS: Findings suggest that attentional processing may promote trait resilience. Future research on preventive interventions should consider these findings.

Stress exposure and the risk for the onset of alcohol use disorders and nicotine dependence in deployed military personnel: the role of prior internalizing disorders.

OBJECTIVE: This prospective study aimed to investigate whether prior internalizing disorders (PIDs) moderate the relationship between stress exposure (SE) and the onset of alcohol use disorders (AUDs) and nicotine dependence (ND) in deployed military personnel. METHODS: 358 male soldiers were examined directly before and 12months after return from deployment using standardized interviews. Combat experiences, concerns about family disruptions, and difficult living and working environment were assessed as different aspects of SE. PID diagnoses (mood disorders (PMDs), anxiety disorders (PADs)) and substance use disorders were defined according to the DSM-IV-TR. RESULTS: PMDs were related to a stronger association between concerns about family disruptions and the risk of AUD onset (OR=7.7, 95% CI 1.8-32.8, p=0.006). The number of PID diagnoses (OR per diagnosis: 1.7, 95% CI 1.0-2.8, p=0.036) and PADs (OR: 2.6, 95% CI 1.1-6.3, p=0.038) were further related to a stronger association between difficult living and working environment and the risk of AUD onset. With regard to ND, PMDs were related to a weaker association between difficult living and working environment and the risk of ND onset (OR=0.4, 95% CI 0.2-0.8, p=0.013). CONCLUSIONS: PIDs might be related to an increased risk for the onset of AUDs but not ND following SE. This effect is probably restricted to specific constellations of PADs, PMDs, comorbid PIDs and specific aspects of SE. These critical constellations of PIDs and SE might be a promising target for future research and could contribute to the development of preventive measures to reduce the risk of AUDs following SE.

Personal values in soldiers after military deployment: associations with mental health and resilience.

BACKGROUND: After military deployment, soldiers are at an increased risk of developing posttraumatic psychiatric disorders. The correlation of personal values with symptoms, however, has not yet been examined within a military context. METHOD: Schwartz's Portrait Values Questionnaire (PVQ), the Posttraumatic Stress Diagnostic Scale (PDS), and the 11-item version of the Resilience Scale (RS-11) were completed by 117 soldiers of the German Armed Forces who had recently been deployed to Afghanistan (n=40 undergoing initial psychiatric treatment, n=77 untreated). RESULTS: Logistic regression showed that the value types of hedonism (-), power (-), tradition (+), and universalism (+) were significantly correlated with the probability and severity of PTSD and whether the participant was in treatment or not. The effects were partially mediated by the RS-11 scale values. CONCLUSIONS: Value types seem to be associated with psychiatric symptoms in soldiers after deployment. These results could contribute to the further development of therapeutic approaches.

Plant cystoliths: a complex functional biocomposite of four distinct silica and amorphous calcium carbonate phases.

Plant cystoliths are mineralized objects that are formed by specialized cells in the leaves of certain plants. The main mineral component of cystoliths by volume is amorphous calcium carbonate (ACC) and the minor component is silica. We show that the silica stalk is formed first and is essential for ACC formation. Furthermore, the cystolith is shown to be composed of four distinct mineral phases with different chemical properties: an almost pure silica phase grades into a Mg-rich silica phase. This Mg-rich silica is overlaid by a relatively stable ACC phase. A bulky and less stable ACC phase encapsulates the first ACC phase. This architecture poses interesting questions about the role of Mg in the silica phase and suggests a strategy for ACC stabilization that takes advantage of a precise regulation of the mineral-growth microenvironment.

A sub-millimeter resolution PET detector module using a multi-pixel photon counter array.

A PET block detector module using an array of sub-millimeter lutetium oxyorthosilicate (LSO) crystals read out by an array of surface-mount, semiconductor photosensors has been developed. The detector consists of a LSO array, a custom acrylic light guide, a 3 x 3 multi-pixel photon counter (MPPC) array (S10362-11-050P, Hamamatsu Photonics, Japan) and a readout board with a charge division resistor network. The LSO array consists of 100 crystals, each measuring 0.8 x 0.8 x 3 mm(3) and arranged in 0.86 mm pitches. A Monte Carlo simulation was used to aid the design and fabrication of a custom light guide to control distribution of scintillation light over the surface of the MPPC array. The output signals of the nine MPPC are multiplexed by a charge division resistor network to generate four position-encoded analog outputs. Flood image, energy resolution and timing resolution measurements were performed using standard NIM electronics. The linearity of the detector response was investigated using gamma-ray sources of different energies. The 10 x 10 array of 0.8 mm LSO crystals was clearly resolved in the flood image. The average energy resolution and standard deviation were 20.0% full-width at half-maximum (FWHM) and +/-5.0%, respectively, at 511 keV. The timing resolution of a single MPPC coupled to a LSO crystal was found to be 857 ps FWHM, and the value for the central region of detector module was 1182 ps FWHM when +/-10% energy window was applied. The nonlinear response of a single MPPC when used to read out a single LSO was observed among the corner crystals of the proposed detector module. However, the central region of the detector module exhibits significantly less nonlinearity (6.5% for 511 keV). These results demonstrate that (1) a charge-sharing resistor network can effectively multiplex MPPC signals and reduce the number of output signals without significantly degrading the performance of a PET detector and (2) a custom light guide to permit light sharing among multiple MPPC and to diffuse and direct scintillation light can reduce the nonlinearity of the detector response within the limited dynamic range of a typical MPPC. As a result, the proposed PET detector module has the potential to be refined for use in high-resolution PET insert applications.

Mapping amorphous calcium phosphate transformation into crystalline mineral from the cell to the bone in zebrafish fin rays.

The continuously forming fin bony rays of zebrafish represent a simple bone model system in which mineralization is temporally and spatially resolved. The mineralized collagen fibrils of the fin bones are identical in structure to those found in all known bone materials. We study the continuous mineralization process within the tissue by using synchrotron microbeam x-ray diffraction and small-angle scattering, combined with cryo-scanning electron microscopy. The former provides information on the mineral phase and the mineral particles size and shape, whereas the latter allows high-resolution imaging of native hydrated tissues. The integration of the two techniques demonstrates that new mineral is delivered and deposited as packages of amorphous calcium phosphate nanospheres, which transform into platelets of crystalline apatite within the collagen matrix.

Strontium is incorporated into mineral crystals only in newly formed bone during strontium ranelate treatment.

Strontium ranelate has been shown to increase bone mass in postmenopausal osteoporosis patients and to reduce fracture risk. The aim of this study was to investigate the potential influence of strontium ranelate (Protelos) treatment on human bone tissue characteristics and quality at the micro- and nanostructural levels. We investigated transiliac biopsies from patients treated for 36 months with strontium ranelate or placebo (n = 5 per group) using synchrotron radiation with a microbeam combining scanning small-angle scattering, X-ray diffraction, and fluorescence spectroscopy (SAXS/XRD/XRF) for a detailed characterization of the mineral crystals within the collagenous bone matrix. A scanning procedure allowed the simultaneous determination of maps of the chemical composition together with thickness, length, and lattice spacing of these mineral crystals within each of the 15- or 25-microm-wide pixels in a thin bone section. The fluorescence results show that only bone packets or osteons formed during the strontium ranelate treatment contain significant amounts of strontium and that up to 0.5 of 10 calcium atoms in the mineral crystals are replaced by strontium, as revealed by a corresponding shift in apatite lattice spacing. The thickness and length of the plate-shaped bone mineral crystals were not affected by the strontium ranelate treatment. As a consequence, there was no indication for a change in human bone tissue quality at the nanoscale after a 36-month treatment of postmenopausal osteoporotic women with strontium ranelate, except for a partial replacement of calcium by strontium ions in the hydroxyapatite crystals, only in newly formed bone.

Simultaneous PET-MRI: a new approach for functional and morphological imaging.

Noninvasive imaging at the molecular level is an emerging field in biomedical research. This paper introduces a new technology synergizing two leading imaging methodologies: positron emission tomography (PET) and magnetic resonance imaging (MRI). Although the value of PET lies in its high-sensitivity tracking of biomarkers in vivo, it lacks resolving morphology. MRI has lower sensitivity, but produces high soft-tissue contrast and provides spectroscopic information and functional MRI (fMRI). We have developed a three-dimensional animal PET scanner that is built into a 7-T MRI. Our evaluations show that both modalities preserve their functionality, even when operated isochronously. With this combined imaging system, we simultaneously acquired functional and morphological PET-MRI data from living mice. PET-MRI provides a powerful tool for studying biology and pathology in preclinical research and has great potential for clinical applications. Combining fMRI and spectroscopy with PET paves the way for a new perspective in molecular imaging.

PET/MR images acquired with a compact MR-compatible PET detector in a 7-T magnet.

PURPOSE: To prospectively use compact avalanche photodiodes instead of photomultiplier tubes to integrate a positron emission tomographic (PET) detector and a 7-T magnetic resonance (MR) imager. MATERIALS AND METHODS: All animal experiments were performed in accordance with the University of Tübingen guidelines and the German law for the protection of animals. A compact lutetium oxyorthosilicate-avalanche photodiode PET detector was built and optimized to operate within a 7-T MR imager. The detector performance was investigated both outside and inside the magnet, and MR image quality was evaluated with and without the PET detector. Two PET detectors were set up opposite each other and operated in coincidence to acquire PET images in the step-and-shoot mode in a mouse head specimen after injection of fluorine 18 fluorodeoxyglucose. RESULTS: The performance of the PET detector when operated inside the magnet during MR image acquisition showed little degradation in energy resolution (increase from 14.6% to 15.9%). The PET detector did not influence MR imaging. The fused PET and MR images showed an anatomic match and no degradation of image quality. CONCLUSION: Simultaneous PET and MR imaging with a 7-T system was deemed feasible.

Evaluation of transmission methodology and attenuation correction for the microPET Focus 220 animal scanner.

An accurate, low noise estimate of photon attenuation in the subject is required for quantitative microPET studies of molecular tracer distributions in vivo. In this work, several transmission-based measurement techniques were compared, including coincidence mode with and without rod windowing, singles mode with two different energy sources ((68)Ge and (57)Co), and postinjection transmission scanning. In addition, the effectiveness of transmission segmentation and the propagation of transmission bias and noise into the emission images were examined. The (57)Co singles measurements provided the most accurate attenuation coefficients and superior signal-to-noise ratio, while (68)Ge singles measurements were degraded due to scattering from the object. Scatter correction of (68)Ge transmission data improved the accuracy for a 10 cm phantom but over-corrected for a mouse phantom. (57)Co scanning also resulted in low bias and noise in postinjection transmission scans for emission activities up to 20 MBq. Segmentation worked most reliably for transmission data acquired with (57)Co but the minor improvement in accuracy of attenuation coefficients and signal-to-noise may not justify its use, particularly for small subjects. We conclude that (57)Co singles transmission scanning is the most suitable method for measured attenuation correction on the microPET Focus 220 animal scanner.

Performance test of an LSO-APD detector in a 7-T MRI scanner for simultaneous PET/MRI.

UNLABELLED: PET combined with CT has proven to be a valuable multimodality imaging device revealing both functional and anatomic information. Although PET/CT has become completely integrated into routine clinical application and also has been used in small-animal imaging, CT provides only limited soft-tissue contrast and, in preclinical studies, exposes the animal to a relatively high radiation dose. Unlike CT, MRI provides good soft-tissue contrast even without application of contrast agents and, furthermore, does not require ionizing radiation. METHODS: This project focused on combining a high-resolution PET scanner with a 7-T MRI system for animal research. Because classic PET detectors based on photomultiplier tubes cannot be used in high magnetic fields, we used a detector technology based on 10 x 10 lutetium oxyorthosilicate crystal arrays and 3 x 3 avalanche photodiode arrays. A ring of such PET detectors will ultimately be used as an insert for the 119-mm-diameter MRI bore. RESULTS: Initial measurements with 1 PET detector module in the 7-T field during application of MRI sequences were encouraging. Position profiles from the PET detectors and a first MR image of a mouse could be acquired simultaneously. CONCLUSION: Further work will concentrate on the construction of a full PET detector ring with compact, integrated electronics.