Stephan G. Nekolla

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Verified

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• Professor
• Professor (Associate) at Technical University of Munich

BACKGROUND Accumulation of CXCR4 (C-X-C motif chemokine receptor 4)–positive immune cells after acute myocardial infarction (AMI) can be visualized by positron emission tomography. For a broader clinical application, there is a need for CXCR4-directed radiotracers labeled with isotopes that can be used with single-photon emission computed tomograph...

Hybrid imaging consists of a combination of two or more imaging modalities, which equally contribute to image information. To date, hybrid cardiovascular imaging can be performed by either merging images acquired on different scanners, or with truly hybrid PET/CT and PET/MR scanners. The European Association of Nuclear Medicine (EANM), and the Euro...

Positron emission tomography/magnetic resonance (PET/MRI) hybrid imaging is now available for over a decade and although the quantity of installed systems is rather low, the number of emerging applications for cardiovascular diseases is still growing. PET/MRI provides integrated images of high quality anatomical and functional assessment obtained b...

Background Radiohybrid PSMA-targeted ligands (rhPSMA) have been introduced as a novel platform for theranostic applications. Among a variety of rhPSMA-ligands developed for radioligand therapy, two stereoisomers [¹⁷⁷Lu]Lu-rhPSMA-10.1 and -10.2 have been synthesized and initially characterized in preclinical experiments with the aim to provide an op...

Background Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) is a novel hybrid imaging method integrating the advances of morphological tissue characterization of MRI with the pathophysiological insights of PET applications. Aim This study evaluated the use of simultaneous 18-FDG PET/MR imaging for characterizing...

Background Inflammatory demyelinating diseases of the central nervous system, such as multiple sclerosis, are significant sources of morbidity in young adults despite therapeutic advances. Current murine models of remyelination have limited applicability due to the low white matter content of their brains, which restricts the spatial resolution of...

Introduction: In pulmonary arterial hypertension (PAH) there is still a need for new prognostic markers to precisely identify the patients before clinical deterioration. We investigated cardiac power index (CPi) as a tool to assess right ventricular (RV) function and overall prognosis. Hypothesis: Hemodynamic changes occurring in PAH assessed with...

Presence of late gadolinium enhancement (LGE) in right ventricle insertion points (RVIPs) has been found in majority of pulmonary arterial hypertension (PAH) patients and is often recognized as evidence of myocardial fibrosis. The aim of the study was to evaluate the relationship between LGE mass and myocardium metabolic activity in RVIPs using PET...

PET/MRI is a relevant application field for prostate cancer management, offering advantages in early diagnosis, staging, and therapy planning. Despite drawbacks such as higher costs, longer acquisition time, and the need for skilled personnel, the technical integration of PET and MRI provides valuable information for detecting primary tumors, ident...

Background Despite advances in therapy, inflammatory demyelinating diseases of the central nervous system, such as multiple sclerosis, remain important causes of morbidity among young adults. Translation of remyelinating paradigms from current murine models is encumbered by the small size and low white matter content of the brains, limiting the spa...

Prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) has shown encouraging results for treatment of metastatic castration-resistant prostate cancer (mCRPC) in the prospective, multicenter, randomized phase II TheraP study. The inclusion criteria for that study comprised a pretherapeutic 68Ga-PSMA-11 PET scan showing sufficient tumor...

Noninvasive imaging techniques, such as SPECT, PET, CT, echocardiography, or MRI, have become essential in cardiovascular research. They allow for the evaluation of biological processes in vivo without the need for invasive procedures. Nuclear imaging methods, such as SPECT and PET, offer numerous advantages, including high sensitivity, reliable qu...

Background: Myocardial perfusion defect (MPD) is common in chronic Chagas cardiomyopathy (CCC) and is associated with inflammation and development of left ventricular systolic dysfunction. We tested the hypothesis that pentoxifylline (PTX) could reduce inflammation and prevent the development of MPD in a model of CCC in hamsters. Methods and resu...

Background In patients with increasing PSA and suspicion for prostate cancer, but previous negative biopsies, PET/MRI is used to test for tumours and target potential following biopsy. We aimed to determine different PSMA PET timing effects on signal kinetics and test its correlation with the patients’ PSA and Gleason scores (GS). Methods A total...

Background: In this study we evaluated the imaging capabilities of a novel Multi-pinhole collimator (MPH-Cardiac) specially designed for nuclear cardiology imaging on a Triple-NaI-detector based SPECT/CT system. Methods: 99mTc point source measurements covering the field of view (FOV) were used to determine tomographic sensitivity (TSpointsource...

Background: Pulsed-field ablation (PFA) is a novel ablation modality for atrial fibrillation (AF) ablating myocardium by electroporation without tissue-heating. With its different mechanism of tissue ablation, it is assumed that lesion creation is divergent to thermal energy sources. 68Ga-fibroblast-activation protein inhibitor (FAPI) PET/CT targe...

Purpose To develop a CT-based radiomic signature to predict biochemical recurrence (BCR) in prostate cancer patients after sRT guided by positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET). Material and methods Consecutive patients, who underwent ⁶⁸Ga-PSMA11-PET/CT-guided sRT from three high-volume centers in Germa...

Positron emission tomography (PET) image reconstruction needs to be corrected for scatter in order to produce quantitatively accurate images. Scatter correction is traditionally achieved by incorporating an estimated scatter sinogram into theforward model during image reconstruction. Existing scatter estimated methods compromise between accuracy an...

Background PET/MRI hybrid imaging in pulmonary arterial hypertension (PAH) provides important prognostic information identifying patients who might benefit from early therapy escalation, as right ventricle (RV) metabolic alterations are linked with hemodynamics and might precede clinical deterioration. Now, we hypothesize that adequate PAH therapy...

The introduction of immunotherapy was a revolution in the treatment of metastatic melanoma. Nevertheless, there are only few clinical parameters to predict response to immunotherapy. The purpose of this study was to identify metastatic patterns that can predict response by using noninvasive 18F-FDG PET/CT imaging. In 93 immunotherapy-treated patien...

Background: In patients with increasing PSA and suspicion for prostate cancer, but previous negative biopsies, PET/MRI is used to test for tumors and target potential following biopsy. We aimed to determine different PSMA PET timing effects on signal kinetics and test its correlation with the patients’ PSA and Gleason scores (GS). Methods: We exami...

Background PET/MRI hybrid imaging in pulmonary arterial hypertension (PAH) provides important prognostic information identifying patients who might benefit from early therapy escalation, as right ventricle (RV) metabolic alterations are linked with hemodynamics and might precede clinical deterioration. Now, we hypothesize that adequate PAH therapy...

Purpose To develop a CT-based radiomic signature to predict biochemical recurrence (BCR) in prostate cancer patients after sRT guided by positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET). Material and Methods Consecutive patients, who underwent ⁶⁸ Ga-PSMA11-PET/CT guided sRT from three high volume centers in Germa...

Introduction: PET/MRI hybrid imaging in pulmonary arterial hypertension (PAH) provides new prognostic parameters, which identify the group of patients who potentially might benefit from early PAH therapy escalation. In previous study we confirmed that right ventricle (RV) metabolic alterations are linked with PAH hemodynamics and both precede clini...

Purpose/Objective(s) Recurrence rate after salvage radiotherapy (sRT) is heterogeneous and additional prognostic markers are needed to improve risk-stratification and guide personalized treatment. We evaluated the association of the maximum standardized uptake value (SUVmax) in positron-emission tomography targeting prostate-specific-membrane-antig...

Background Microvascular myocardial perfusion defect (MPD) is frequent in chronic Chagas cardiomyopathy (CCC) and may be involved in the pathophysiologic process that leads to left ventricular systolic dysfunction (LVSD). However, there is scarcity of studies addressing the histopathological meaning of MPD in CCC and its correlation with endothelia...

Background Inflammatory processes play an important role in pulmonary arterial hypertension (PAH) pathophysiology. We previously confirmed that in case of right ventricle (RV) failure, changes of cytokines' levels are correlated with myocardial metabolic and hemodynamic alterations observed in PET/MRI hybrid imaging. Presence of late gadolinium enh...

Background This work investigated the impact of different cardiac gating methods on the assessment of cardiac function by FDG-PET in a cross-validation PET/MR study. Methods and results MR- and PET-based left ventricular end-diastolic, end-systolic volumes, and ejection fraction (EDV, ESV, and EF) were delineated in 30 patients with a PET/MR exami...

Zusammenfassung Die wachsende Zahl potenzieller Radioisotope und die steigende Nachfrage nach Radiopharmazeutika (RP) für Bildgebung- und Therapiezwecke haben dazu geführt, dass ihre biomedizinische Anwendung im modernen Gesundheitswesen immer mehr an Bedeutung gewinnt. Die nuklearmedizinische Technologie wird heute als ein wesentliches Instrument...

We present guidelines by the European Association of Nuclear Medicine (EANM) for routine quality control (QC) of PET-CT and PET-MR systems. These guidelines are partially based on the current EANM guidelines for routine quality control of Nuclear Medicine instrumentation but focus more on the inherent multimodal aspect of the current, state-of-the-...

Purpose This study aims to evaluate the association of the maximum standardized uptake value (SUVmax) in positron-emission tomography targeting prostate-specific membrane antigen (PSMA-PET) prior to salvage radiotherapy (sRT) on biochemical recurrence free survival (BRFS) in a large multicenter cohort. Methods Patients who underwent ⁶⁸ Ga-PSMA11-P...

Background In this study we evaluated the imaging capabilities of a novel Multi-pinhole collimator (MPH-Cardiac) specially designed for nuclear cardiology imaging on a triple head NaI(Tl) detector based SPECT/CT system. Methods 99mTc point source measurements covering the field-of-view (FOV) were used to determine tomographic sensitivity (TSpointso...

Background Cadmium-zinc-telluride (CZT)-based detectors exhibit higher diagnostic sensitivity in myocardial perfusion imaging (MPI) than conventional Anger-MPI for detection of coronary artery disease (CAD); however, reduced specificity and diagnostic accuracy of CZT-MPI were observed. This study aims to compare these different camera systems and t...

Purpose This study aims to evaluate the association of the maximum standardized uptake value (SUVmax) in positron-emission tomography targeting prostate-specific-membrane-antigen (PSMA-PET) prior to savage radiotherapy (sRT) on biochemical recurrence free survival (BRFS) in a large multicenter cohort. Methods Patients who underwent ⁶⁸Ga-PSMA11-PET...

Background. Cytokines soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and interleukin 6 (IL-6) are involved in immune response, proliferation, apoptosis, and cardiovascular pathologies. We have previously confirmed that changes of their platelet or plasma contents are associated with pulmonary arterial hypertension (PAH). The...

Purpose ⁶⁸ Ga-fibroblast-activation protein inhibitor (FAPI) positron emission tomography (PET) is a novel technique targeting FAP-alpha. This protein is expressed by activated fibroblasts which are the main contributors to tissue remodeling. The aim of this proof-of-concept study was to assess ⁶⁸ Ga-FAPI uptake in the pulmonary vein (PV) region of...

Background: Radiohybrid prostate-specific membrane antigen (rhPSMA) ligands such as 18F-rhPSMA-7 are a new class of theranostic agents in clinical development for prostate cancer. We compared preclinical dosimetry and human biodistribution of 18F-rhPSMA-7 with that of single diastereoisomer form, 18F-rhPSMA-7.3. Methods: Preclinical dosimetry wa...

A B S T R A C T Background and Objective The Spline Reconstruction Technique (SRT) is a fast algorithm based on a novel numerical implementation of an analytic representation of the inverse Radon transform. The purpose of this study is to provide a comparison between SRT, Filtered Back-Projection (FBP), Ordered Subset Expectation Maximization 2D (...

Purpose In PSMA-ligand PET/CT imaging, standardized evaluation frameworks and image-derived parameters are increasingly used to support prostate cancer staging. Clinical applicability remains challenging wherever manual measurements of numerous suspected lesions are required. Deep learning methods are promising for automated image analysis, typical...

Purpose To evaluate the performance of combined PET and multiparametric MRI (mpMRI) radiomics for the group-wise prediction of postsurgical Gleason scores (psGSs) in primary prostate cancer (PCa) patients. Methods Patients with PCa, who underwent [ ⁶⁸ Ga]Ga-PSMA-11 PET/MRI followed by radical prostatectomy, were included in this retrospective anal...

This clinically oriented book provides an up-to-date review on the various hybrid imaging modalities that may be employed for the purpose of cardiac imaging. After discussion of generic aspects of hybrid imaging, SPECT/CT, PET/CT, and PET/MRI are each considered in depth. In addition, information is provided on upcoming technologies, such as dedica...

Background In pulmonary arterial hypertension (PAH) increased afterload leads to adaptive processes of the right ventricle (RV) that help to maintain arterio-ventricular coupling of RV and preserve cardiac output, but with time the adaptive mechanisms fail. In this study, we propose a multimodal approach which allows to estimate prognostic value of...

When this article was written, it coincided with the 11th anniversary of the installation of our PET/MR device in Munich. In fact, this was the first fully integrated device to be in clinical use. During this time, we have observed many interesting behaviors, to put it kindly. However, it is more critical that in this process, our understanding of...

Background The clinical indication to revascularization of coronary chronic total occlusions (CTO) is set on viability assessment through well-established imaging methods. Precise characterization of the myocardium allows a better interventional risk stratification before revascularization. Hybrid positron emission tomography/magnetic resonance (PE...

Historically, radionuclide imaging has been the key to the success and widespread clinical application of non-invasive techniques for detection of myocardial ischaemia. Today, the use of myocardial perfusion single photon emission computed tomography (SPECT) for the diagnostic and prognostic workup of coronary artery disease is supported by a very...

Simultaneous PET-MR imaging has shown potential for the comprehensive assessment of myocardial health from a single examination. Furthermore, MR-derived respiratory motion information has been shown to improve PET image quality by incorporating this information into the PET image reconstruction. Separately, MR-based anatomically guided PET image re...

Our previous study has demonstrated the feasibility of noninvasive imaging of fibroblast activation protein (FAP)-expression after myocardial infarction (MI) in MI-territory in a rat model with ⁶⁸ Ga-FAPI-04-PET. In the current extended clinical case, we sought to delineate cardiac uptake of ⁶⁸ Ga-FAPI-04 in a patient after MI with clinical indicat...

Purpose: Increased angiogenesis after myocardial infarction is considered an important favorable prognostic parameter. The αvβ3 integrin is a key mediator of cell-cell and cell-matrix interactions and an important molecular target for imaging of neovasculature and repair processes after MI. Thus, imaging of αvβ3 expression might provide a novel bi...

PurposeAfter a decade of PET/MR, the case of attenuation correction (AC) remains open. The initial four-compartment (air, water, fat, soft tissue) Dixon-based AC scheme has since been expanded with several features, the latest being MR field-of-view extension and a bone atlas. As this potentially changes quantification, we evaluated the impact of t...

Heart failure is a complex clinical syndrome arising from reduced cardiac contractile function and affecting a significant portion of the adult population while increasing rapidly with age. The most important cause of heart failure is systolic dysfunction which can be detected by means of non-invasive imaging. The aim of this chapter is to provide...

Objectives: Radiohybrid prostate-specific membrane antigen (rhPSMA)-ligands are applicable as radiochemical twins for both diagnostic PET imaging and endoradiotherapy. Based on preliminary data as diagnostic ligand, the isomer rhPSMA-7.3 is a promising candidate for potential endoradiotherapy. The aim of this preclinical evaluation was to assess bi...

PurposeTo evaluate myocardial viability assessment with hybrid 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography/magnetic resonance imaging ([18F]FDG-PET/MR) in predicting left ventricular (LV) wall motion recovery after percutaneous revascularisation of coronary chronic total occlusion (CTO).Methods and resultsForty-nine patients with C...

Introduction: Right ventricular (RV) function is a major determinant of survival in patients with pulmonary arterial hypertension (PAH). In our previous study, we confirmed that increased RV fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) (presented as higher ratio of FDG uptake of RV to LV) was associated with progressive RV...

The objective of this retrospective study was to assess the detection rate (DR), positive predictive value (PPV) and correct detection rate (CDR) of 18F-rhPSMA-7 PET/CT in biochemical recurrence (BCR) of prostate cancer (PCa) after radical prostatectomy (RP) using composite validation. Methods:18F-rhPSMA-7 PET/CT scans of patients with BCR between...

Here, we present a case with a pacemaker due to an atrioventricular (AV) block 2 Mobitz type, in whom a gating failure resulted in a relevant underestimation of cardiac function in myocardial perfusion scintigraphy. A set of quality control steps for gating errors is proposed.

Objectives: Radiohybrid prostate-specific membrane antigen (rhPSMA)-ligands are applicable as radiochemical twins for both diagnostic PET imaging and endoradiotherapy. Based on preliminary data as diagnostic ligand, the isomer rhPSMA-7.3 is a promising candidate for potential endoradiotherapy. The aim of this preclinical evaluation was to assess b...

Background: Fibroblast activation protein (FAP) as a specific marker of activated fibroblasts can be visualized by positron emission tomography (PET) using Ga-68-FAP inhibitors (FAPI). Gallium-68-labeled FAPI is increasingly used in the staging of various cancers. In addition, the first cases of theranostic approaches have been reported. In this w...

Rationale: Pheochromocytomas and paragangliomas are a rare tumor entity originating from adreno-medullary chromaffin cells in the adrenal medulla or in sympathetic, paravertebral ganglia outside the medulla. Especially small lesions are difficult to detect by conventional CT or MR imaging and even by SPECT imaging with currently available radiotrac...

Objective Right ventricular (RV) function is a major determinant of survival in patients with pulmonary arterial hypertension (PAH). Metabolic alterations may precede haemodynamic and clinical deterioration. Increased RV fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) was recently associated with progressive RV dysfunction in...

The aim of this study was to acquire the transient MRI signal of hyperpolarized tracers and their metabolites efficiently, for which specialized imaging sequences are required. In this work, a multi-echo balanced steady-state free precession (me-bSSFP) sequence with Iterative Decomposition with Echo Asymmetry and Least squares estimation (IDEAL) re...

Zusammenfassung Die Herzperfusionsszintigrafie ist seit Jahrzehnten ein gut etabliertes Verfahren, dass bei guter diagnostischer Genauigkeit ausgesprochen routinetauglich ist. Dieser Übersichtsartikel fasst den aktuellen Stand der Technik und neue methodische Entwicklungen zusammen. Darüber hinaus werden Aspekte der Auswertung, der Strahlenbelastun...