Publications by authors named "Andreas S Kunz"

Article Synopsis
  • The TFCC (Triangular Fibrocartilage Complex) has several components that have been better understood recently, and current classifications for it are somewhat lacking.
  • The review focuses on the anatomy, types of lesions visible in MRI, and compares these with existing literature, introducing the new CUP classification and illustrating it with images.
  • Accurate imaging requires advanced techniques like gadolinium-enhanced MRI or MR/CT arthrography, which are necessary for identifying the minute structures of the TFCC, especially the important stabilizing lamina fovealis.
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Rationale And Objectives: This study investigates the dose burden of photon-counting detector (PCD) lung CT with ultra-high-resolution (UHR) and standard mode using organ-based tube current modulation (OBTCM).

Materials And Methods: An anthropomorphic Alderson-Rando phantom was scanned in UHR and standard mode with and without OBTCM on three dose levels (IQ 5, 20, 50). Effective radiation dose was determined by thermoluminescent dosimetry in 13 measurement sites and compared with the calculated effective dose derived from the dose-length product.

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Background Contrast-unenhanced abdominal CT is the imaging standard for urinary calculi detection; however, studies comparing photon-counting detector (PCD) CT and energy-integrating detector (EID) CT dose-reduction potentials are lacking. Purpose To compare the radiation dose and image quality of optimized EID CT with those of an experimental PCD CT scan protocol including tin prefiltration in patients suspected of having urinary calculi. Materials and Methods This retrospective single-center study included patients who underwent unenhanced abdominal PCD CT or EID CT for suspected urinary caliculi between February 2022 and March 2023.

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Rationale And Objectives: To assess image quality and radiation dose of ultra-high-pitch CT pulmonary angiography (CTPA) with free-breathing technique for diagnosis of pulmonary embolism using a photon-counting detector (PCD) CT compared to matched energy-integrating detector (EID)-based single-energy CTPA.

Materials And Methods: Fifty-one PCD-CTPAs were prospectively compared to 51 CTPAs on a third-generation dual-source EID-CT. CTPAs were acquired with an ultra-high-pitch protocol with free-breathing technique (40 mL contrast medium, pitch 3.

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Rationale And Objectives: This study investigates the performance of tomosynthesis in the presence of osteosynthetic implants, aiming to overcome superimposition-induced limitations in conventional radiograms.

Materials And Methods: After surgical fracture induction and subsequent osteosynthesis, 8 cadaveric fracture models (wrist, metacarpus, ankle, metatarsus) were scanned with the prototypical tomosynthesis mode of a multiuse x-ray system. Tomosynthesis protocols at 60, 80, and 116 kV (sweep angle 10°, 13 FPS) were compared with standard radiograms.

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Article Synopsis
  • The study aimed to analyze how helical pitch and gantry rotation time affect image quality and file size in ultrahigh-resolution photon-counting CT scans of cadaveric specimens.
  • Scans were conducted with varying pitches and rotation times, revealing that while scan duration differed significantly, image quality decreased with high-pitch and short rotation protocols despite consistent dose measures.
  • Findings indicate that careful selection of pitch and rotation time is crucial for optimizing image quality in clinical practices, as longer acquisition times lead to significantly larger raw data sizes, which can limit practical use.
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This study investigated whether virtual monoenergetic images (VMIs) and iodine mapping based on dual-energy CT (DECT) provide advantages in the assessment of endometrial cancer. A dual-source DECT was performed for primary staging of histologically proven endometrioid adenocarcinoma in 21 women (66.8 ± 12.

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Rationale And Objectives: Aiming to offset image quality limitations in radiographs due to superimposition, this study investigates the diagnostic potential of appendicular skeleton tomosynthesis.

Materials And Methods: Eight cadaveric extremities (four hands and feet) were examined employing the prototypical tomosynthesis mode of a twin robotic X-ray scanner. 12 protocols with varying sweep angles (10, 20 vs.

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Article Synopsis
  • The study investigates ways to reduce radiation doses in abdominal CT scans for diagnosing kidney stones, using spectral shaping and tube voltage modulation.
  • Eight cadaveric specimens were scanned at different tube voltages and doses, and the image quality was evaluated both quantitatively and subjectively by radiologists.
  • Results showed that using a tin filter at 100 kVp provided better image quality at lower doses compared to higher voltages and conventional imaging methods, indicating effective radiation dose reduction without compromising diagnostic quality.
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Objectives: Image acquisition in ultra-high-resolution (UHR) scan mode does not impose a dose penalty in photon-counting CT (PCCT). This study aims to investigate the dose saving potential of using UHR instead of standard-resolution PCCT for lumbar spine imaging.

Materials And Methods: Eight cadaveric specimens were examined with 7 dose levels (5-35 mGy) each in UHR (120 × 0.

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Background: Time is a scarce resource for physicians. One medical task is the request for radiological diagnostics. This process is characterized by high administrative complexity and sometimes considerable time consumption.

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Introduction: With increasing spatial resolution, diffusion-weighted imaging (DWI) may be suitable for morphologic lesion characterization in breast MRI - an area that has traditionally been occupied by dynamic contrast-enhanced imaging (DCE). This investigation compared DWI with b values of 800 and 1600 s/mm to DCE for lesion morphology assessment in high-resolution breast MRI at 3 Tesla.

Material And Methods: Multiparametric breast MRI was performed in 91 patients with 93 histopathologically proven lesions (31 benign, 62 malignant).

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Background: With the emergence of photon-counting CT, ultrahigh-resolution (UHR) imaging can be performed without dose penalty. This study aims to directly compare the image quality of UHR and standard resolution (SR) scan mode in femoral artery angiographies.

Methods: After establishing continuous extracorporeal perfusion in four fresh-frozen cadaveric specimens, photon-counting CT angiographies were performed with a radiation dose of 5 mGy and tube voltage of 120 kV in both SR and UHR mode.

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Purpose: To investigate the metal artifact suppression potential of combining tin prefiltration and virtual monoenergetic imaging (VMI) for osseous microarchitecture depiction in ultra-high-resolution (UHR) photon-counting CT (PCCT) of the lower extremity.

Method: Derived from tin-filtered UHR scans at 140 kVp, polychromatic datasets (T3D) and VMI reconstructions at 70, 110, 150, and 190 keV were compared in 117 patients with lower extremity metal implants (53 female; 62.1 ± 18.

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Article Synopsis
  • - The study investigated a deep learning-based imaging method to speed up diffusion-weighted imaging (DWI) for breast MRI, targeting better spatial resolution and reduced scan times.
  • - Involving 133 women, the research found that the deep learning techniques (DL and SRDL) could cut scan times by 39%, with SRDL yielding the highest quality ratings among images assessed by radiologists.
  • - Although standard DWI provided a better signal-to-noise ratio, both deep learning methods showed promising structural similarity and slight increases in apparent diffusion coefficient values compared to standard DWI.
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Aims: Tablets are being adopted as teaching medium in medical education more frequently. Here we compared two teaching formats in a radiology seminar using a tablet-based student-centred approach guided by teachers and traditional presentation-based, teacher-centred instruction. The aim was to investigate the effects on academic performance, estimated learning gain, didactic quality, as well as how teacher charisma and student digital affinity influence these elements.

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Rationale And Objectives: This experimental study investigates the potential of lumbar spine tomosynthesis to offset the traditional limitations of radiographic and computed tomography imaging, that is, superimposition of anatomy and disregard of physiological load-bearing.

Materials And Methods: A gantry-free twin robotic scanner was used to obtain lateral radiographs and tomosyntheses of the lumbar spine under weight-bearing conditions in eight body donors. Tomosynthesis protocols varied in terms of sweep angle (20 versus 40°), scan time (2.

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Purpose: Leg torsion analysis can provide valuable information in symptomatic patients after total knee arthroplasty. However, extensive beam-hardening and photon-starvation artifacts limit diagnostic assessability and dose reduction potential. For this study, we investigated the reproducibility of rotational measurements in ultra-low-dose photon-counting CT with spectral shaping via tin prefiltration.

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Multiple myeloma (MM) frequently induces persisting osteolytic manifestations despite hematologic treatment response. This study aimed to establish a biometrically valid study endpoint for bone remineralization through quantitative and qualitative analyses in sequential CT scans. Twenty patients (seven women, 58 ± 8 years) with newly diagnosed MM received standardized induction therapy comprising the anti-SLAMF7 antibody elotuzumab, carfilzomib, lenalidomide, and dexamethasone (E-KRd).

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Objectives: The aim of this study was to investigate potential benefits of ultra-high resolution (UHR) over standard resolution scan mode in ultra-low dose photon-counting detector CT (PCD-CT) of the lung.

Materials And Methods: Six cadaveric specimens were examined with 5 dose settings using tin prefiltration, each in UHR (120 × 0.2 mm) and standard mode (144 × 0.

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Recent dissection studies resulted in the introduction of the term "chiasma antebrachii", which represents an intersection of the flexor digitorum superficialis (FDS) tendons for digits 2 and 3 in the distal third of the forearm. This retrospective investigation aimed to provide an MRI-based morphologic analysis of the chiasma antebrachii. In 89 patients (41 women, 39.

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This study evaluated the influence of different vascular reconstruction kernels on the image quality of CT angiographies of the lower extremity runoff using a 1st-generation photon-counting-detector CT (PCD-CT) compared with dose-matched examinations on a 3rd-generation energy-integrating-detector CT (EID-CT). Inducing continuous extracorporeal perfusion in a human cadaveric model, we performed CT angiographies of eight upper leg arterial runoffs with radiation dose-equivalent 120 kVp acquisition protocols (CTDI 5 mGy). Reconstructions were executed with different vascular kernels, matching the individual modulation transfer functions between scanners.

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This study was designed to investigate the image quality of ultra-high-resolution ankle arthrography employing a photon-counting detector CT. Bilateral arthrograms were acquired in four cadaveric specimens with full-dose (10 mGy) and low-dose (3 mGy) scan protocols. Three convolution kernels with different spatial frequencies were utilized for image reconstruction (ρ; Br98: 39.

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Purpose: The effect of static forces under load limits the prognostic value of lumbar spine CT in a horizontal position. Using a gantry-free scanner architecture, this study was designed to assess the feasibility of weight-bearing cone-beam CT (CBCT) of the lumbar spine and to establish the most dose-effective combination of scan parameters.

Methods: Eight formalin-fixated cadaveric specimens were examined with a gantry-free CBCT system in upright position with the aid of a dedicated positioning backstop.

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