Publications by authors named "Rafael Heiss"

Identifying syndesmotic instability in ankle fractures using conventional radiographs is still a major challenge. In this study we trained a convolutional neural network (CNN) to classify the fracture utilizing the AO-classification (AO-44 A/B/C) and to simultaneously detect syndesmosis instability in the conventional radiograph by leveraging the intraoperative stress testing as the gold standard. In this retrospective exploratory study we identified 700 patients with rotational ankle fractures at a university hospital from 2019 to 2024, from whom 1588 digital radiographs were extracted to train, validate, and test a CNN.

View Article and Find Full Text PDF

Unlabelled: Few studies have examined post-COVID-19 sequelae in children, particularly regarding cardiopulmonary capacity. Longitudinal data are especially scarce. This study aimed to retest pediatric patients previously assessed in a cross-sectional design.

View Article and Find Full Text PDF

Objectives: Recently introduced potassium-39-( 39 K)-MRI provides a noninvasive approach to assess typically high intracellular K + -levels and can be combined with sodium-23-( 23 Na)-MRI. The aim of this study was to evaluate 39 K/ 23 Na muscle ion homeostasis in hypokalemic periodic paralysis (HypoPP), a rare muscular ion channelopathy, using 7 T MRI.

Materials And Methods: Lower legs of patients with HypoPP and healthy controls were prospectively examined between August 2022 and July 2023 (case-control study).

View Article and Find Full Text PDF

Combined Na/K MRI at 7 T can highlight ion disturbances in skeletal muscle tissue. In this work, we investigated if the apparent tissue potassium concentration (aTPC) can be determined in fatty replaced muscles of patients with facio-scapulo-humeral muscular dystrophy (FSHD) and if it can provide additional information to the fat replacement and the apparent tissue sodium concentration (aTSC). The lower leg of 14 patients (six females, eight males; mean age 47.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to see if changes in MRI-defined bone marrow lesions (BMLs) and inflammatory markers are linked to cartilage loss in knees with osteoarthritis over 24 months.
  • It analyzed data from 629 participants, finding that knees with no BMLs showed significantly less cartilage loss, while those with increasing BML size experienced more cartilage loss.
  • The results suggest that preventing the growth of BMLs and worsening of Hoffa-synovitis could help reduce cartilage deterioration in osteoarthritis patients.
View Article and Find Full Text PDF

Pompe disease (PD) is a rare autosomal recessive glycogen storage disorder that causes proximal muscle weakness and loss of respiratory function. While enzyme replacement therapy (ERT) is the only effective treatment, biomarkers for disease monitoring are scarce. Following ex vivo biomarker validation in phantom studies, we apply multispectral optoacoustic tomography (MSOT), a laser- and ultrasound-based non-invasive imaging approach, in a clinical trial (NCT05083806) to image the biceps muscles of 10 late-onset PD (LOPD) patients and 10 matched healthy controls.

View Article and Find Full Text PDF

Objective: To compare image quality and diagnostic performance of 3T and 7T magnetic resonance imaging (MRI) for direct depiction of finger flexor pulleys A2, A3 and A4 before and after artificial pulley rupture in an ex-vivo model using anatomic preparation as reference.

Materials And Methods: 30 fingers from 10 human cadavers were examined at 3T and 7T before and after being subjected to iatrogenic pulley rupture. MRI protocols were comparable in duration, both lasting less than 22 min.

View Article and Find Full Text PDF

This narrative review explores recent advancements and applications of modern low-field (≤ 1 Tesla) magnetic resonance imaging (MRI) in musculoskeletal radiology. Historically, high-field MRI systems (1.5 T and 3 T) have been the standard in clinical practice due to superior image resolution and signal-to-noise ratio.

View Article and Find Full Text PDF
Article Synopsis
  • The study evaluated changes in the anterior cruciate ligament (ACL) and cartilage following ACL repair using advanced MRI techniques.
  • After 1.5 years, most ACLs showed normal signal intensity and increased width, with some fraying that didn't affect overall knee function as measured by clinical scores.
  • T2 mapping indicated that the post-repair ACL’s tissue composition was similar to a healthy ACL, however, there were signs of cartilage degradation in the patients compared to controls.
View Article and Find Full Text PDF

Purpose: Broader clinical adoption of breast magnetic resonance imaging (MRI) faces challenges such as limited availability and high procedural costs. Low-field technology has shown promise in addressing these challenges. We report our initial experience using a next-generation scanner for low-field breast MRI at 0.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigated the cardiopulmonary effects of post-COVID-19 in children and adolescents, using treadmill exercise testing to gather data.
  • 20 children with post-COVID-19 were compared to 28 age- and sex-matched controls, revealing reduced oxygen uptake in the affected group.
  • Although there were differences in exercise capacity, no significant problems with heart or lung function were found, suggesting that deconditioning may explain the symptoms experienced by children after COVID-19.
View Article and Find Full Text PDF

Intracranial hemorrhages require an immediate diagnosis to optimize patient management and outcomes, and CT is the modality of choice in the emergency setting. We aimed to evaluate the performance of the first scanner-integrated artificial intelligence algorithm to detect brain hemorrhages in a routine clinical setting. This retrospective study includes 435 consecutive non-contrast head CT scans.

View Article and Find Full Text PDF

Background: To analyze regional variations in T2 and T2* relaxation times in wrist joint cartilage and the triangular fibrocartilage complex (TFCC) at 3 and 7 T and to compare values between field strengths.

Methods: Twenty-five healthy controls and 25 patients with chronic wrist pain were examined at 3 and 7 T on the same day using T2- and T2*-weighted sequences. Six different regions of interest (ROIs) were evaluated for cartilage and 3 ROIs were evaluated at the TFCC based on manual segmentation.

View Article and Find Full Text PDF

Objectives: To compare a novel, non-contrast, flow-independent, 3D isotropic magnetic resonance angiography (MRA) sequence that combines respiration compensation, electrocardiogram (ECG)-triggering, undersampling, and Dixon water-fat separation with an ECG-triggered aortic high-pitch computed tomography angiography (CTA) of the aorta.

Materials And Methods: Twenty-five patients with recent CTA were scheduled for non-contrast MRA on a 3 T MRI. Aortic diameters and cross-sectional areas were measured on MRA and CTA using semiautomatic measurement tools at 11 aortic levels.

View Article and Find Full Text PDF

Accurate diagnosis of muscle injuries is a challenge in everyday clinical practice and may have profound impact on the recovery and return-to-play decisions of professional athletes particularly in soccer. Imaging techniques such as ultrasound and magnetic resonance imaging (MRI), in addition to the medical history and clinical examination, make a significant contribution to the timely structural assessment of muscle injuries. The severity of a muscle injury determined by imaging findings has a decisive influence on therapy planning and affects prognosis.

View Article and Find Full Text PDF

Background: To assess morphological and functional alterations of the skeletal muscle in exercise-induced delayed onset muscle soreness (DOMS) using 7 Tesla (T) magnetic resonance imaging (MRI).

Methods: DOMS was induced in 16 volunteers performing an eccentric exercise protocol of the calf muscles of one randomized leg. 7 T MRI including T1w- (0.

View Article and Find Full Text PDF

Purpose: Sport climbing may lead to tissue adaptation including finger cartilage before apparent surface damage is detectable. The main aim was to assess finger cartilage composition with T2 mapping in young, active climbers and to compare the results to a non-climbers' collective. A secondary aim was to compare whether differences in cartilage T2 times are observed between older vs.

View Article and Find Full Text PDF

Purpose: Microvascular blood flow (MBF) and its intramuscular regulation are of importance for physiological responsiveness and adaptation. The quantifiable in-vivo monitoring of MBF after cycling or systemic cold-water exposure may reveal new insights into capillary regulatory mechanisms. This study aimed to assess the role of exercise and cold therapy on MBF by using contrast-enhanced ultrasound (CEUS).

View Article and Find Full Text PDF

This article describes recent advances in quantitative imaging of musculoskeletal extremity sports injuries, citing the existing literature evidence and what additional evidence is needed to make such techniques applicable to clinical practice. Compositional and functional MRI techniques including T2 mapping, diffusion tensor imaging, and sodium imaging as well as contrast-enhanced US have been applied to quantify pathophysiologic processes and biochemical compositions of muscles, tendons, ligaments, and cartilage. Dual-energy and/or spectral CT has shown potential, particularly for the evaluation of osseous and ligamentous injury (eg, creation of quantitative bone marrow edema maps), which is not possible with standard single-energy CT.

View Article and Find Full Text PDF

(1) Purpose: to compare right ventricular (RV) functional parameters in children with surgically repaired congenital heart disease (CHD) using single/double breath hold (BH) and free-breathing (FB) real-time compressed sensing (CS) cine cardiac magnetic resonance (cMRI) with standard retrospective segmented multi breath hold (RMB) cine cMRI. (2) Methods: Twenty patients with CHD underwent BH and FB, as well as RMB cine cMRI, at 3T to obtain a stack of continuous axial images of the RV. Two radiologists independently performed qualitative analysis of the image quality (rated on a 5-point scale; 1 = non-diagnostic to 5 = excellent) and quantitative analysis of the RV volume measurements.

View Article and Find Full Text PDF

Objectives: Temporomandibular disorders (TMDs) are common and may cause persistent functional limitations and pain. Magnetic resonance imaging (MRI) at 1.5 and 3 T is commonly applied for the evaluation of the temporomandibular joint (TMJ).

View Article and Find Full Text PDF

Objectives: The aim of this study was to evaluate the accuracy of modern low-field magnetic resonance imaging (MRI) for lung nodule detection and to correlate nodule size measurement with computed tomography (CT) as reference.

Materials And Methods: Between November 2020 and July 2021, a prospective clinical trial using low-field MRI at 0.55 T was performed in patients with known pulmonary nodules from a single academic medical center.

View Article and Find Full Text PDF

Objectives: Vestibular schwannoma (VS) is the most common mass of the internal auditory canal (IAC) and is responsible for unilateral sensorineural hearing loss. Magnetic resonance imaging (MRI) at 1.5 T and 3 T is the standard of care for the evaluation of VS, and the feasibility of using modern low-field MRI for imaging of the IAC has not yet been elucidated.

View Article and Find Full Text PDF

The proximal hamstring complex is a highly vulnerable area that is especially prone to injury. Proximal hamstring tendinopathies (PHTs) remain challenging in diagnosis, treatment, rehabilitation, and prevention due to a large variety of different injuries, slow healing response, persistent symptoms, and functional impairments. PHTs are often misdiagnosed or underdiagnosed, leading to delayed treatment and therapy failure.

View Article and Find Full Text PDF