Publications by authors named "Thomas Lund Andersen"

Background: Magnetic resonance imaging (MRI) cerebral blood volume (CBV) measurements improve the diagnosis of recurrent gliomas. The study investigated the prognostic value of dynamic contrast-enhanced (DCE) CBV imaging in treated IDH wildtype glioblastoma when added to MRI or amino acid positron emission tomography (PET).

Methods: Hybrid [F]FET PET/MRI with 2CXM (2-compartment exchange model) DCE from 86 adult patients with suspected recurrent or residual glioblastoma were retrospectively analyzed.

View Article and Find Full Text PDF

Hyperpolarized 1-13C-pyruvate magnetic resonance spectroscopy (MRS) and MRS imaging (MRSI) offer noninvasive and real-time direct assessment of the altered metabolism of cancer cells known as the Warburg effect-a key hallmark of cancer. When combined with simultaneously acquired 18F-FDG PET in a PET/MR scanner, coined hyperPET by us, this dual-modality may unveil cancer-type specific glucose metabolic phenotypes with potential implications for patient prognostication, treatment-response assessment, and prediction. We here present the first human data of simultaneously acquired hyperpolarized MRS/MRSI and PET performed in a PET/MR scanner-and the first human hyperpolarized MRS/MRSI data from a patient with lymphoma.

View Article and Find Full Text PDF

Background: Treatment of patients with low-grade and high-grade gliomas is highly variable due to the large difference in survival expectancy. New non-invasive tools are needed for risk stratification prior to treatment. The urokinase plasminogen activator receptor (uPAR) is expressed in several cancers, associated with poor prognosis and may be non-invasively imaged using uPAR-PET.

View Article and Find Full Text PDF

Objective: We present an algorithm to estimate the delay between a tissue time-activity curve and a blood input curve at a single-voxel level tested on whole-body data from a long-axial field-of-view scanner with tracers of different noise characteristics.

Methods: Whole-body scans of 15 patients divided equally among three tracers, namely [O]HO, [F]FDG and [Cu]Cu-DOTATATE, which were used in development and testing of the algorithm. Delay times were estimated by fitting the cumulatively summed input function and tissue time-activity curve with special considerations for noise.

View Article and Find Full Text PDF

The outstanding capabilities of modern Positron Emission Tomography (PET) to highlight small tumor lesions and provide pathological function assessment are at peril from image quality degradation caused by respiratory and cardiac motion. However, the advent of the long axial field-of-view (LAFOV) scanners with increased sensitivity, alongside the precise time-of-flight (TOF) of modern PET systems, enables the acquisition of ultrafast time resolution images, which can be used for estimating and correcting the cyclic motion. 0.

View Article and Find Full Text PDF

Cross-sectional imaging supplements endoscopy in detecting disease manifestations in inflammatory bowel diseases (IBD). This study aimed to evaluate the accuracy of PET/MRI in a paediatric population suspected of IBD. This prospective study consecutively included patients aged 8-17 years under diagnostic evaluation for IBD.

View Article and Find Full Text PDF

Stress is a ubiquitous challenge in modern societies. Symptoms range from mood swings and cognitive impairment to autonomic symptoms. This study explores the link between work-related stress and the neurobiological element of brain processing, testing the hypothesis that patients with occupational stress have altered cerebral glucose consumption compared to healthy controls.

View Article and Find Full Text PDF

The accurate estimation of the tracer arterial blood concentration is crucial for reliable quantitative kinetic analysis in PET. In the current work, we demonstrate the automatic extraction of an image-derived input function (IDIF) from a CT AI-based aorta segmentation subsequently resliced to a dynamic PET series acquired on a Siemens Vision Quadra long-axial field of view scanner in 10 human subjects scanned with [O]HO. We demonstrate that the extracted IDIF is quantitative and in excellent agreement with a delay- and dispersion-corrected sampled arterial input function (AIF).

View Article and Find Full Text PDF

Incorrect scatter scaling of positron emission tomography (PET) images can lead to halo artifacts, quantitative bias, or reconstruction failure. Tail-fitted scatter scaling (TFSS) possesses performance limitations in multiple cases. This study aims to investigate a novel method for scatter scaling: maximum-likelihood scatter scaling (MLSS) in scenarios where TFSS tends to induce artifacts or are observed to cause reconstruction abortion.

View Article and Find Full Text PDF

Neuroimaging holds an essential position in global healthcare, as brain-related disorders are a substantial and growing burden. Non-degenerative disorders such as stress, depression and anxiety share common function related traits of diffuse and fluctuating changes, such as change in brain-based functions of mood, behavior and cognitive abilities, where underlying physiological mechanism remain unresolved. In this study we developed a novel application for studying intra-subject task-activated brain function by the quantitative physiological measurement of the change in glucose metabolism in a single scan setup.

View Article and Find Full Text PDF

Purpose: Conventional magnetic resonance imaging (MRI) can for glioma assessment be supplemented by positron emission tomography (PET) imaging with radiolabeled amino acids such as O-(2-[F]fluoroethyl)-L-tyrosine ([F]FET), which provides additional information on metabolic properties. In neuro-oncology, patients often undergo brain and skull altering treatment, which is known to challenge MRI-based attenuation correction (MR-AC) methods and thereby impact the simplified semi-quantitative measures such as tumor-to-brain ratio (TBR) used in clinical routine. The aim of the present study was to examine the applicability of our deep learning method, DeepDixon, for MR-AC in [F]FET PET/MRI scans of a post-surgery glioma cohort with metal implants.

View Article and Find Full Text PDF

We compared the image quality and quantification parameters through bayesian penalized likelihood reconstruction algorithm (Q.Clear) and ordered subset expectation maximization (OSEM) algorithm for 2-[F]FDG-PET/CT scans performed for response monitoring in patients with metastatic breast cancer in prospective setting. We included 37 metastatic breast cancer patients diagnosed and monitored with 2-[F]FDG-PET/CT at Odense University Hospital (Denmark).

View Article and Find Full Text PDF

Background: Deep convolutional neural networks have demonstrated robust and reliable PET attenuation correction (AC) as an alternative to conventional AC methods in integrated PET/MRI systems. However, its whole-body implementation is still challenging due to anatomical variations and the limited MRI field of view. The aim of this study is to investigate a deep learning (DL) method to generate voxel-based synthetic CT (sCT) from Dixon MRI and use it as a whole-body solution for PET AC in a PET/MRI system.

View Article and Find Full Text PDF

Patients with brain metastases, the most common intracranial tumor, have an average survival ranging from a few months to 40 months, and new treatment initiatives are needed. Cryoablation is a minimally invasive, well-tolerated, and effective procedure commonly applied for treatment of renal tumors and certain other malignancies. We aimed to examine the clinical usefulness of this procedure in a step-by-step program starting with cerebral cryoablation in healthy pigs.

View Article and Find Full Text PDF

Angiogenesis is crucial in tissue repair and prevents scar tissue formation following an ischemic event such as myocardial infarction. The ischemia induces formation of new capillaries, which have high expression of integrin αβ. [Ga]Ga-NODAGA-E[(cRGDyK)] ([Ga]Ga-RGD) is a promising PET-radiotracer reflecting angiogenesis by binding to integrin αβ.

View Article and Find Full Text PDF

The diagnosis of a malignant brain tumour is often associated with a poor prognosis. Current treatment is surgical resection followed by radio-chemotherapy. Surgical resection is most favourable in relation to survival time.

View Article and Find Full Text PDF

Background: The use of hybrid PET/MRI for clinical staging is growing in several cancer forms and, consequently, PET/MRI has also gained interest in the assessment of non-small cell lung cancer (NSCLC) and lung lesions. However, lung evaluation with PET/MRI is associated with challenges related to technical issues and diagnostic image quality. We, therefore, investigated the published literature on PET/MRI for clinical staging in NSCLC or lung nodule detection specifically addressing diagnostic accuracy and technical issues.

View Article and Find Full Text PDF

Purpose: PET/MRI was introduced for clinical use in 2011 and is now an established modality for the imaging of brain and certain pelvic cancers, whereas clinical use for the imaging of other forms of cancer is not yet widespread. We therefore systematically investigated what has been published on the use of PET/MRI compared to PET/CT in the imaging of cancers outside the brain, focusing on clinical areas of application related to diagnosis, staging and restaging.

Methods: A systematic search of PubMed/MEDLINE, Embase and the Cochrane Library was performed.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Notice

Message: fwrite(): Write of 34 bytes failed with errno=28 No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 272

Backtrace:

A PHP Error was encountered

Severity: Warning

Message: session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)

Filename: Unknown

Line Number: 0

Backtrace: