Lars-Arne Schaafs

Charité Universitätsmedizin Berlin | Charité · Institute of Radiology

Stiffening of central large vessels is considered a key pathophysiologic factor within the cardiovascular system. Current diagnostic parameters such as pulse wave velocity (PWV) indirectly measure aortic stiffness, a hallmark of coronary diseases. The aim of the present study was to perform elastography of the proximal abdominal aorta based on exte...

The purpose of this study was to evaluate the sensitivity of quantitative time-harmonic ultrasound elastography (THE) of the inferior vena cava (IVC) and abdominal aorta (AA) to changes in central volume status. THE of the IVC and AA was performed in 20 healthy volunteers before and after oral intake of 1 L of water and before or during passive leg...

Objectives: The aim of this study was to investigate ultrasound time-harmonic elastography for quantifying aortic stiffness in vivo in the context of aging and arterial hypertension. Materials and methods: Seventy-four participants (50 healthy participants and 24 participants with long-standing hypertension) were prospectively included between J...

Objectives: The aim of this study was to investigate blood pressure dependency of ultrasound time-harmonic elastography (THE) for quantification of aortic stiffness. Materials and methods: Thoracoabdominal aortas were surgically removed from 9 healthy domestic pigs and prepared for elastographic experiments. All vessels were connected to a salin...

Objectives: The aim of this study was to investigate the potential of stroboscopic-wavefield-sampling-based multifrequency magnetic resonance elastography (sMRE) for quantifying the stiffness of the human thoracic and abdominal aorta in vivo. Materials and methods: The sMRE of the thoracic and abdominal aorta was performed at 1.5 T field strengt...

Smoking is a significant cardiovascular risk factor that causes stiffening of the central arteries, especially the aorta. While vessel stiffness can be determined indirectly by measuring pulse wave velocity, elastography allows image-based determination of vessel stiffness while at the same time providing information on vascular morphology. This st...

Background Left bundle branch block (LBBB) is a ventricular conduction delay with high prevalence. Aim of our study is to identify possible recurring patterns of artefacts in late gadolinium enhancement (LGE) imaging in patients with LBBB who undergo cardiac magnetic resonance imaging (MRI) and to define parameters of mechanical dyssynchrony associ...

Background In radiomics studies, differences in the volume of interest (VOI) are often inevitable and may confound the extracted features. We aimed to correct this confounding effect of VOI variability by applying parametric maps with a fixed voxel size. Methods Ten scans of a cup filled with sodium chloride solution were scanned using a multislic...

Objectives Accurate radiological differentiation of parotid tumors remains challenging despite recent technical advances in quantitative medical imaging. Multifrequency magnetic resonance elastography (MRE) could provide additional information on viscoelastic properties of normal and abnormal biological tissues. This study investigates the feasibil...

Objectives The Neck Imaging Reporting and Data System (NI-RADS) is an increasingly utilized risk stratification tool for imaging surveillance after treatment for head and neck cancer. This study aims to measure the impact of supervision by subspecialized radiologists on diagnostic accuracy of NI-RADS when initial reading is performed by residents....

Background: Imaging surveillance is important for the early diagnosis of recurrence following de nitive treatment for oral squamous cell carcinoma (OSCC). The Neck Imaging Reporting and Data System (NI-RADS) provides a standardized template for surveillance imaging and categorizes probability of recurrence at the primary site and the neck (cervical...

Background and purpose: The Neck Imaging Reporting and Data System was introduced to assess the probability of recurrence in surveillance imaging after treatment of head and neck cancer. This study investigated inter- and intrareader agreement in interpreting contrast-enhanced CT after treatment of oral cavity and oropharyngeal squamous cell carci...

Purpose Reducing contrast media injection speed while maintaining iodine flux is a promising workaround to lower or avoid contrast media-related discomfort during CT examinations. This approach demands contrast media with a higher concentration to guarantee excellent image quality. It remains unclear whether these concentration changes affect the p...

Purpose To evaluate the diagnostic performance of diastolic function parameters derived from long-axis (LAX) planimetry compared with short-axis (SAX) volumetry in cardiac magnetic resonance imaging. Materials and Methods Cine steady-state free precession (SSFP) datasets of 15 healthy participants (8 young and 7 middle aged) and 25 patients with ec...

To evaluate the performance of two iterative reconstruction algorithms in low-dose paranasal sinus computed tomography (CT). Sinus CT scans were reconstructed using Adaptive Iterative Dose Reduction 3D (AIDR 3D, n = 36 patients) or Sinogram Affirmed Iterative Reconstruction (SAFIRE, n = 32 patients). Reconstructed images were evaluated regarding su...

Purpose: Computed tomography (CT)-guided periradicular infiltration therapy has emerged as an effective treatment option for patients with low back pain. Concern about radiation exposure requires approaches allowing significant dose reduction. The purpose of this study is to evaluate the need for iterative reconstruction software in CT-guided peri...

Background Computed tomography (CT)-guided periradicular infiltration remains a frequent interventional procedure for treatment of low back pain. Purpose To present an interventional ultra-low-dose protocol for CT-guided periradicular infiltration therapy and assess its application at different body mass index (BMI) levels. Material and Methods O...

Purpose: Computed tomography (CT)-guided periradicular infiltration has become an accepted procedure for treating radiculopathy-associated low back pain. The purpose of this study is to compare spot scanning and segmental helical planning CT in terms of dose reduction. Materials and methods: Eighty-five patients underwent CT-guided single-site l...

Objective: To evaluate the feasibility and image quality of low-dose computed tomography (CT) of the paranasal sinuses using iterative reconstruction with adaptive-iterative dose reduction (AIDR) in 3D in comparison with conventional image protocols of older scanner generations. Methods: Sinus CT scans of 136 patients were assessed retrospective...

Aim: To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic d...

Objectives Perfusion imaging (PI) is susceptible to confounding factors such as motion artefacts as well as delay and dispersion (D/D). We evaluate the influence of different post-processing algorithms on hypoperfusion assessment in PI analysis software packages to improve the clinical accuracy of stroke PI. Methods Fifty patients with acute ischae...

Background: There is an ongoing debate whether stroke patients presenting with minor or moderate symptoms benefit from thrombolysis. Up until now, stroke severity on admission is typically measured with the NIHSS, and subsequently used for treatment decision. Hypothesis: Acute MRI lesion volume assessment can aid in therapy decision for iv-tPA i...