@article{ConradsGrunzHuflageetal.2023,
  author    = {Conrads, Nora and Grunz, Jan-Peter and Huflage, Henner and Luetkens, Karsten Sebastian and Feldle, Philipp and Grunz, Katharina and K{\"o}hler, Stefan and Westermaier, Thomas},
  title     = {Accuracy of pedicle screw placement using neuronavigation based on intraoperative 3D rotational fluoroscopy in the thoracic and lumbar spine},
  series = {Archives of Orthopaedic and Trauma Surgery},
  volume    = {143},
  journal   = {Archives of Orthopaedic and Trauma Surgery},
  number    = {6},
  doi       = {10.1007/s00402-022-04514-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324966},
  pages     = {3007-3013},
  year      = {2023},
  abstract  = {Introduction In spinal surgery, precise instrumentation is essential. This study aims to evaluate the accuracy of navigated, O-arm-controlled screw positioning in thoracic and lumbar spine instabilities. Materials and methods Posterior instrumentation procedures between 2010 and 2015 were retrospectively analyzed. Pedicle screws were placed using 3D rotational fluoroscopy and neuronavigation. Accuracy of screw placement was assessed using a 6-grade scoring system. In addition, screw length was analyzed in relation to the vertebral body diameter. Intra- and postoperative revision rates were recorded. Results Thoracic and lumbar spine surgery was performed in 285 patients. Of 1704 pedicle screws, 1621 (95.1\%) showed excellent positioning in 3D rotational fluoroscopy imaging. The lateral rim of either pedicle or vertebral body was protruded in 25 (1.5\%) and 28 screws (1.6\%), while the midline of the vertebral body was crossed in 8 screws (0.5\%). Furthermore, 11 screws each (0.6\%) fulfilled the criteria of full lateral and medial displacement. The median relative screw length was 92.6\%. Intraoperative revision resulted in excellent positioning in 58 of 71 screws. Follow-up surgery due to missed primary malposition had to be performed for two screws in the same patient. Postsurgical symptom relief was reported in 82.1\% of patients, whereas neurological deterioration occurred in 8.9\% of cases with neurological follow-up. Conclusions Combination of neuronavigation and 3D rotational fluoroscopy control ensures excellent accuracy in pedicle screw positioning. As misplaced screws can be detected reliably and revised intraoperatively, repeated surgery for screw malposition is rarely required.},
  language  = {en}
}
@phdthesis{Grunz2018,
  author    = {Grunz, Jan-Peter},
  title     = {Benefit Finding von Patienten mit Prostatakrebs im Behandlungsverlauf},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162180},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Bei Prostatakrebspatienten zeigte sich eine niedrige Tendenz zu Benefit Finding am Behandlungsbeginn und drei Monate sp{\"a}ter (Mt1 = 2,87; SDt1 = 0,96; Mt2 = 2,92; SDt2 = 0,94). Die gesundheitsbezogene Lebensqualit{\"a}t sank dagegen im Verlauf der 12 Wochen nach Therapiebeginn deutlich (Mt1 = 74,06; SDt1 = 18,70; Mt2 = 70,81; SDt2 = 19,19). Benefit Finding und gesundheitsbezogene Lebensqualit{\"a}t korrelierten zu beiden Untersuchungsterminen jeweils schwach negativ miteinander. Der Zusammenhang beider Variablen war jedoch in Regressionsanalysen f{\"u}r den zeitlichen Verlauf {\"u}ber drei Monate nicht reproduzierbar. Zusammenfassend muss deshalb postuliert werden, dass sich Benefit Finding unmittelbar bei Therapiebeginn f{\"u}r Prostatatkrebspatienten nicht als Pr{\"a}diktor f{\"u}r verbesserte Lebensqualit{\"a}t nach drei Monaten eignet und vice versa.},
  subject      = {Sinnsuche},
  language  = {de}
}
@article{GrunzPennigFieberetal.2021,
  author    = {Grunz, Jan-Peter and Pennig, Lenhard and Fieber, Tabea and Gietzen, Carsten Herbert and Heidenreich, Julius Frederik and Huflage, Henner and Gruschwitz, Philipp and Kuhl, Philipp Josef and Petritsch, Bernhard and Kosmala, Aleksander and Bley, Thorsten Alexander and Gassenmaier, Tobias},
  title     = {Twin robotic x-ray system in small bone and joint trauma: Impact of cone-beam computed tomography on treatment decisions},
  series = {European Radiology},
  volume    = {31},
  journal   = {European Radiology},
  issn      = {0938-7994},
  doi       = {10.1007/s00330-020-07563-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235233},
  pages     = {3600-3609},
  year      = {2021},
  abstract  = {Objectives Trauma evaluation of extremities can be challenging in conventional radiography. A multi-use x-ray system with cone-beam CT (CBCT) option facilitates ancillary 3-D imaging without repositioning. We assessed the clinical value of CBCT scans by analyzing the influence of additional findings on therapy. Methods Ninety-two patients underwent radiography and subsequent CBCT imaging with the twin robotic scanner (76 wrist/hand/finger and 16 ankle/foot/toe trauma scans). Reports by on-call radiologists before and after CBCT were compared regarding fracture detection, joint affliction, comminuted injuries, and diagnostic confidence. An orthopedic surgeon recommended therapy based on reported findings. Surgical reports (N = 52) and clinical follow-up (N = 85) were used as reference standard. Results CBCT detected more fractures (83/64 of 85), joint involvements (69/53 of 71), and multi-fragment situations (68/50 of 70) than radiography (all p < 0.001). Six fractures suspected in radiographs were ruled out by CBCT. Treatment changes based on additional information from CBCT were recommended in 29 patients (31.5\%). While agreement between advised therapy before CBCT and actual treatment was moderate (κ = 0.41 [95\% confidence interval 0.35-0.47]; p < 0.001), agreement after CBCT was almost perfect (κ = 0.88 [0.83-0.93]; p < 0.001). Diagnostic confidence increased considerably for CBCT studies (p < 0.001). Median effective dose for CBCT was 4.3 μSv [3.3-5.3 μSv] compared to 0.2 μSv [0.1-0.2 μSv] for radiography. Conclusions CBCT provides advantages for the evaluation of acute small bone and joint trauma by detecting and excluding extremity fractures and fracture-related findings more reliably than radiographs. Additional findings induced therapy change in one third of patients, suggesting substantial clinical impact.},
  language  = {en}
}
@article{HuflageFieberFaerberetal.2022,
  author    = {Huflage, Henner and Fieber, Tabea and F{\"a}rber, Christian and Knarr, Jonas and Veldhoen, Simon and Jordan, Martin C. and Gilbert, Fabian and Bley, Thorsten Alexander and Meffert, Rainer H. and Grunz, Jan-Peter and Schmalzl, Jonas},
  title     = {Interobserver reliability of scapula fracture classifications in intra- and extra-articular injury patterns},
  series = {BMC Musculoskeletal Disorders},
  volume    = {23},
  journal   = {BMC Musculoskeletal Disorders},
  number    = {1},
  doi       = {10.1186/s12891-022-05146-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299795},
  year      = {2022},
  abstract  = {Background Morphology and glenoid involvement determine the necessity of surgical management in scapula fractures. While being present in only a small share of patients with shoulder trauma, numerous classification systems have been in use over the years for categorization of scapula fractures. The purpose of this study was to evaluate the established AO/OTA classification in comparison to the classification system of Euler and R{\"u}edi (ER) with regard to interobserver reliability and confidence in clinical practice. Methods Based on CT imaging, 149 patients with scapula fractures were retrospectively categorized by two trauma surgeons and two radiologists using the classification systems of ER and AO/OTA. To measure the interrater reliability, Fleiss kappa (κ) was calculated independently for both fracture classifications. Rater confidence was stated subjectively on a five-point scale and compared with Wilcoxon signed rank tests. Additionally, we computed the intraclass correlation coefficient (ICC) based on absolute agreement in a two-way random effects model to assess the diagnostic confidence agreement between observers. Results In scapula fractures involving the glenoid fossa, interrater reliability was substantial (κ = 0.722; 95\% confidence interval [CI] 0.676-0.769) for the AO/OTA classification in contrast to moderate agreement (κ = 0.579; 95\% CI 0.525-0.634) for the ER classification system. Diagnostic confidence for intra-articular fracture patterns was superior using the AO/OTA classification compared to ER (p < 0.001) with higher confidence agreement (ICC: 0.882 versus 0.831). For extra-articular fractures, ER (κ = 0.817; 95\% CI 0.771-0.863) provided better interrater reliability compared to AO/OTA (κ = 0.734; 95\% CI 0.692-0.776) with higher diagnostic confidence (p < 0.001) and superior agreement between confidence ratings (ICC: 0.881 versus 0.912). Conclusions The AO/OTA classification is most suitable to categorize intra-articular scapula fractures with glenoid involvement, whereas the classification system of Euler and R{\"u}edi appears to be superior in extra-articular injury patterns with fractures involving only the scapula body, spine, acromion and coracoid process.},
  language  = {en}
}
@article{JordanBroeerFischeretal.2022,
  author    = {Jordan, Martin C. and Br{\"o}er, David and Fischer, Christian and Heilig, Philipp and Gilbert, Fabian and H{\"o}lscher-Doht, Stefanie and Kalogirou, Charis and Popp, Kevin and Grunz, Jan-Peter and Huflage, Henner and Jakubietz, Rafael G. and Erg{\"u}n, S{\"u}leyman and Meffert, Rainer H.},
  title     = {Development and preclinical evaluation of a cable-clamp fixation device for a disrupted pubic symphysis},
  series = {Communications Medicine},
  volume    = {2},
  journal   = {Communications Medicine},
  number    = {1},
  doi       = {10.1038/s43856-022-00227-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299800},
  year      = {2022},
  abstract  = {Background Traumatic separation of the pubic symphysis can destabilize the pelvis and require surgical fixation to reduce symphyseal gapping. The traditional approach involves open reduction and the implantation of a steel symphyseal plate (SP) on the pubic bone to hold the reposition. Despite its widespread use, SP-fixation is often associated with implant failure caused by screw loosening or breakage. Methods To address the need for a more reliable surgical intervention, we developed and tested two titanium cable-clamp implants. The cable served as tensioning device while the clamp secured the cable to the bone. The first implant design included a steel cable anterior to the pubic symphysis to simplify its placement outside the pelvis, and the second design included a cable encircling the pubic symphysis to stabilize the anterior pelvic ring. Using highly reproducible synthetic bone models and a limited number of cadaver specimens, we performed a comprehensive biomechanical study of implant stability and evaluated surgical feasibility. Results We were able to demonstrate that the cable-clamp implants provide stability equivalent to that of a traditional SP-fixation but without the same risks of implant failure. We also provide detailed ex vivo evaluations of the safety and feasibility of a trans-obturator surgical approach required for those kind of fixation. Conclusion We propose that the developed cable-clamp fixation devices may be of clinical value in treating pubic symphysis separation.},
  language  = {en}
}
@article{HerzStefanescuLohretal.2022,
  author    = {Herz, Stefan and Stefanescu, Maria R. and Lohr, David and Vogel, Patrick and Kosmala, Aleksander and Terekhov, Maxim and Weng, Andreas M. and Grunz, Jan-Peter and Bley, Thorsten A. and Schreiber, Laura M.},
  title     = {Effects of image homogeneity on stenosis visualization at 7 T in a coronary artery phantom study: With and without B1-shimming and parallel transmission},
  series = {PloS One},
  volume    = {17},
  journal   = {PloS One},
  number    = {6},
  doi       = {10.1371/journal.pone.0270689},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300129},
  year      = {2022},
  abstract  = {Background To investigate the effects of B\(_1\)-shimming and radiofrequency (RF) parallel transmission (pTX) on the visualization and quantification of the degree of stenosis in a coronary artery phantom using 7 Tesla (7 T) magnetic resonance imaging (MRI). Methods Stenosis phantoms with different grades of stenosis (0\%, 20\%, 40\%, 60\%, 80\%, and 100\%; 5 mm inner vessel diameter) were produced using 3D printing (clear resin). Phantoms were imaged with four different concentrations of diluted Gd-DOTA representing established arterial concentrations after intravenous injection in humans. Samples were centrally positioned in a thorax phantom of 30 cm diameter filled with a custom-made liquid featuring dielectric properties of muscle tissue. MRI was performed on a 7 T whole-body system. 2D-gradient-echo sequences were acquired with an 8-channel transmit 16-channel receive (8 Tx / 16 Rx) cardiac array prototype coil with and without pTX mode. Measurements were compared to those obtained with identical scan parameters using a commercially available 1 Tx / 16 Rx single transmit coil (sTX). To assess reproducibility, measurements (n = 15) were repeated at different horizontal angles with respect to the B0-field. Results B\(_1\)-shimming and pTX markedly improved flip angle homogeneity across the thorax phantom yielding a distinctly increased signal-to-noise ratio (SNR) averaged over a whole slice relative to non-manipulated RF fields. Images without B\(_1\)-shimming showed shading artifacts due to local B\(_1\)\(^+\)-field inhomogeneities, which hampered stenosis quantification in severe cases. In contrast, B\(_1\)-shimming and pTX provided superior image homogeneity. Compared with a conventional sTX coil higher grade stenoses (60\% and 80\%) were graded significantly (p<0.01) more precise. Mild to moderate grade stenoses did not show significant differences. Overall, SNR was distinctly higher with B\(_1\)-shimming and pTX than with the conventional sTX coil (inside the stenosis phantoms 14\%, outside the phantoms 32\%). Both full and half concentration (10.2 mM and 5.1 mM) of a conventional Gd-DOTA dose for humans were equally suitable for stenosis evaluation in this phantom study. Conclusions B\(_1\)-shimming and pTX at 7 T can distinctly improve image homogeneity and therefore provide considerably more accurate MR image analysis, which is beneficial for imaging of small vessel structures.},
  language  = {en}
}
@article{GrunzGietzenLuetkensetal.2020,
  author    = {Grunz, Jan-Peter and Gietzen, Carsten Herbert and Luetkens, Karsten and Wagner, Matthias and Kalb, Karlheinz and Bley, Thorsten Alexander and Lehmkul, Luka and van Schoonhoven, J{\"o}rg and Gassenmaier, Tobias and Schmitt, Rainer},
  title     = {The importance of radial multiplanar reconstructions for assessment of triangular fibrocartilage complex injury in CT arthrography of the wrist},
  series = {BMC Musculoskeletal Disorders},
  volume    = {21},
  journal   = {BMC Musculoskeletal Disorders},
  doi       = {10.1186/s12891-020-03321-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236075},
  year      = {2020},
  abstract  = {Background: Triangular fibrocartilage complex (TFCC) lesions commonly cause ulnar-sided wrist pain and instability of the distal radioulnar joint. Due to its triangular shape, discontinuity of the TFCC is oftentimes difficult to visualize in radiological standard planes. Radial multiplanar reconstructions (MPR) may have the potential to simplify diagnosis in CT wrist arthrography. The objective of this study was to assess diagnostic advantages provided by radial MPR over standard planes for TFCC lesions in CT arthrography. Methods: One hundred six patients (49 women, 57 men; mean age 44.2 ± 15.8 years) underwent CT imaging after wrist arthrography. Two radiologists (R1, R2) retrospectively analyzed three randomized datasets for each CT arthrography. One set contained axial, coronal and sagittal planes (MPR\(_{Standard}\)), while the other two included an additional radial reconstruction with the rotating center either atop the ulnar styloid (MPR\(_{Styloid}\)) or in the ulnar fovea (MPR\(_{Fovea}\)). Readers evaluated TFCC differentiability and condition. Suspected lesions were categorized using Palmer's and Atzei's classification and diagnostic confidence was stated on a fivepoint Likert scale. Results: Compared to standard planes, differentiability of the superficial and deep TFCC layer was superior in radial reconstructions (R1/R2; MPR\(_{Fovea}\): p < 0.001; MPRStyloid: p ≤ 0.007). Palmer and Atzei lesions were present in 86.8\% (92/106) and 52.8\% (56/106) of patients, respectively. Specificity, sensitivity and accuracy for central Palmer lesions did not differ in radial and standard MPR. For peripheral Atzei lesions, sensitivity (MPR\(_{Standard}\) 78.6\%/80.4\%, MPR\(_{Styloid}\) 94.6\%/94.6\%, MPR\(_{Fovea}\) 91.1\%/89.3\%) and accuracy (MPR\(_{Standard}\) 86.8\%/86.8\%, MPR\(_{Styloid}\) 96.2\%/96.2\%, MPR\(_{Fovea}\) 94.3\%/93.4\%) improved with additional styloid-centered (p = 0.004/0.008) and foveacentered (p = 0.039/0.125) reconstructions. No substantial difference was observed between both radial MPR (p = 0.688/0.250). Interrater agreement was almost perfect for each dataset (κ\(_{Standard}\) = 0.876, κ\(_{Styloid}\) = 0.894, κ\(_{Fovea}\) = 0.949). Diagnostic confidence increased with addition of either radial MPR (p < 0.001). Conclusions: Ancillary radial planes improve accuracy and diagnostic confidence for detection of peripheral TFCC lesions in CT arthrography of the wrist.},
  language  = {en}
}
@article{LuetkensErguenHuflageetal.2021,
  author    = {Luetkens, Karsten Sebastian and Erg{\"u}n, S{\"u}leyman and Huflage, Henner and Kunz, Andreas Steven and Gietzen, Carsten Herbert and Conrads, Nora and Pennig, Lenhard and Goertz, Lukas and Bley, Thorsten Alexander and Gassenmaier, Tobias and Grunz, Jan-Peter},
  title     = {Dose reduction potential in cone-beam CT imaging of upper extremity joints with a twin robotic x-ray system},
  series = {Scientific Reports},
  volume    = {11},
  journal   = {Scientific Reports},
  number    = {1},
  doi       = {10.1038/s41598-021-99748-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270429},
  year      = {2021},
  abstract  = {Cone-beam computed tomography is a powerful tool for 3D imaging of the appendicular skeleton, facilitating detailed visualization of bone microarchitecture. This study evaluated various combinations of acquisition and reconstruction parameters for the cone-beam CT mode of a twin robotic x-ray system in cadaveric wrist and elbow scans, aiming to define the best possible trade-off between image quality and radiation dose. Images were acquired with different combinations of tube voltage and tube current-time product, resulting in five scan protocols with varying volume CT dose indices: full-dose (FD; 17.4 mGy), low-dose (LD; 4.5 mGy), ultra-low-dose (ULD; 1.15 mGy), modulated low-dose (mLD; 0.6 mGy) and modulated ultra-low-dose (mULD; 0.29 mGy). Each set of projection data was reconstructed with three convolution kernels (very sharp [Ur77], sharp [Br69], intermediate [Br62]). Five radiologists subjectively assessed the image quality of cortical bone, cancellous bone and soft tissue using seven-point scales. Irrespective of the reconstruction kernel, overall image quality of every FD, LD and ULD scan was deemed suitable for diagnostic use in contrast to mLD (very sharp/sharp/intermediate: 60/55/70\%) and mULD (0/3/5\%). Superior depiction of cortical and cancellous bone was achieved in FD\(_{Ur77}\) and LD\(_{Ur77}\) examinations (p < 0.001) with LD\(_{Ur77}\) scans also providing favorable bone visualization compared to FD\(_{Br69}\) and FD\(_{Br62}\) (p < 0.001). Fleiss' kappa was 0.618 (0.594-0.641; p < 0.001), indicating substantial interrater reliability. In this study, we demonstrate that considerable dose reduction can be realized while maintaining diagnostic image quality in upper extremity joint scans with the cone-beam CT mode of a twin robotic x-ray system. Application of sharper convolution kernels for image reconstruction facilitates superior display of bone microarchitecture.},
  language  = {en}
}
@article{GrunzWenigKunzetal.2020,
  author    = {Grunz, Jan-Peter and Wenig, Andreas Max and Kunz, Andreas Steven and Veyhl-Wichmann, Maike and Schmitt, Rainer and Gietzen, Carsten Herbert and Pennig, Lenhard and Herz, Stefan and Erg{\"u}n, S{\"u}leyman and Bley, Thorsten Alexander and Gassenmaier, Tobias},
  title     = {3D cone-beam CT with a twin robotic x-ray system in elbow imaging: comparison of image quality to high-resolution multidetector CT},
  series = {European Radiology Experimental},
  volume    = {4},
  journal   = {European Radiology Experimental},
  doi       = {10.1186/s41747-020-00177-y},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229877},
  year      = {2020},
  abstract  = {Background Elbow imaging is challenging with conventional multidetector computed tomography (MDCT), while cone-beam CT (CBCT) provides superior options. We compared intra-individually CBCT versus MDCT image quality in cadaveric elbows. Methods A twin robotic x-ray system with new CBCT mode and a high-resolution clinical MDCT were compared in 16 cadaveric elbows. Both systems were operated with a dedicated low-dose (LD) protocol (equivalent volume CT dose index [CTDI\(_{vol(16 cm)}\)] = 3.3 mGy) and a regular clinical scan dose (RD) protocol (CTDI\(_{vol(16 cm)}\) = 13.8 mGy). Image quality was evaluated by two radiologists (R1 and R2) on a seven-point Likert scale, and estimation of signal intensity in cancellous bone was conducted. Wilcoxon signed-rank tests and intraclass correlation coefficient (ICC) statistics were used. Results The CBCT prototype provided superior subjective image quality compared to MDCT scans (for RD, p ≤ 0.004; for LD, p ≤ 0.001). Image quality was rated very good or excellent in 100\% of the cases by both readers for RD CBCT, 100\% (R1) and 93.8\% (R2) for LD CBCT, 62.6\% and 43.8\% for RD MDCT, and 0.0\% and 0.0\% for LD MDCT. Single-measure ICC was 0.95 (95\% confidence interval 0.91-0.97; p < 0.001). Software-based assessment supported subjective findings with less "undecided" pixels in CBCT than dose-equivalent MDCT (p < 0.001). No significant difference was found between LD CBCT and RD MDCT. Conclusions In cadaveric elbow studies, the tested cone-beam CT prototype delivered superior image quality compared to high-end multidetector CT and showed a potential for considerable dose reduction.},
  language  = {en}
}
@article{HuflageKarstenKunzetal.2021,
  author    = {Huflage, Henner and Karsten, Sebastian and Kunz, Andreas Steven and Conrads, Nora and Jakubietz, Rafael Gregor and Jakubietz, Michael Georg and Pennig, Lenhard and Goertz, Lukas and Bley, Thorsten Alexander and Schmitt, Rainer and Grunz, Jan-Peter},
  title     = {Improved diagnostic accuracy for ulnar-sided TFCC lesions with radial reformation of 3D sequences in wrist MR arthrography},
  series = {European Radiology},
  volume    = {31},
  journal   = {European Radiology},
  number    = {12},
  issn      = {1432-1084},
  doi       = {10.1007/s00330-021-08024-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266512},
  pages     = {9399-9407},
  year      = {2021},
  abstract  = {Objectives Triangular fibrocartilage complex (TFCC) injuries frequently cause ulnar-sided wrist pain and can induce distal radioulnar joint instability. With its complex three-dimensional structure, diagnosis of TFCC lesions remains a challenging task even in MR arthrograms. The aim of this study was to assess the added diagnostic value of radial reformatting of isotropic 3D MRI datasets compared to standard planes after direct arthrography of the wrist. Methods Ninety-three patients underwent wrist MRI after fluoroscopy-guided multi-compartment arthrography. Two radiologists collectively analyzed two datasets of each MR arthrogram for TFCC injuries, with one set containing standard reconstructions of a 3D thin-slice sequence in axial, coronal and sagittal orientation, while the other set comprised an additional radial plane view with the rotating center positioned at the ulnar styloid. Surgical reports (whenever available) or radiological reports combined with clinical follow-up served as a standard of reference. In addition, diagnostic confidence and assessability of the central disc and ulnar-sided insertions were subjectively evaluated. Results Injuries of the articular disc, styloid and foveal ulnar attachment were present in 20 (23.7\%), 10 (10.8\%) and 9 (9.7\%) patients. Additional radial planes increased diagnostic accuracy for lesions of the styloid (0.83 vs. 0.90; p = 0.016) and foveal (0.86 vs. 0.94; p = 0.039) insertion, whereas no improvement was identified for alterations of the central cartilage disc. Readers' confidence (p < 0.001) and assessability of the ulnar-sided insertions (p < 0.001) were superior with ancillary radial reformatting. Conclusions Access to the radial plane view of isotropic 3D sequences in MR arthrography improves diagnostic accuracy and confidence for ulnar-sided TFCC lesions.},
  language  = {en}
}
@article{HoffmannJanssenKannoetal.2020,
  author    = {Hoffmann, Jan V. and Janssen, Jan P. and Kanno, Takayuki and Shibutani, Takayuki and Onoguchi, Masahisa and Lapa, Constantin and Grunz, Jan-Peter and Buck, Andreas K. and Higuchi, Takahiro},
  title     = {Performance evaluation of fifth-generation ultra-high-resolution SPECT system with two stationary detectors and multi-pinhole imaging},
  series = {EJNMMI Physics},
  volume    = {7},
  journal   = {EJNMMI Physics},
  doi       = {10.1186/s40658-020-00335-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230361},
  year      = {2020},
  abstract  = {Background Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT\(^+\)). Methods The new U-SPECT5-E with two stationary detectors was used for acquiring data with \(^{99m}\)Tc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT\(^+\) for comparison. Results Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT\(^+\). In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7\% (XUHR-M), 29.1\% (GP-M, U-SPECT5-E), 16.3\% (GP-M, U-SPECT\(^+\)) and 23.0\% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR. Conclusions While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.},
  language  = {en}
}
@article{JanssenHoffmannKannoetal.2020,
  author    = {Janssen, Jan P. and Hoffmann, Jan V. and Kanno, Takayuki and Nose, Naoko and Grunz, Jan-Peter and Onoguchi, Masahisa and Chen, Xinyu and Lapa, Constantin and Buck, Andreas K. and Higuchi, Takahiro},
  title     = {Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging},
  series = {Scientific Reports},
  volume    = {10},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-020-75696-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230616},
  year      = {2020},
  abstract  = {We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available \(^{99m}\)Tc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with \(^{99m}\)Tc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with similar to 100 MBq [\(^{99m}\)TcTc-MIBI or similar to 150 MBq [\(^{99m}\)Tc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1="very poor" to 5="very good". Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5\%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.},
  language  = {en}
}
@article{GrunzSailerLangetal.2022,
  author    = {Grunz, Jan-Peter and Sailer, Lukas and Lang, Patricia and Sch{\"u}le, Simone and Kunz, Andreas Steven and Beer, Meinrad and Hackenbroch, Carsten},
  title     = {Dual-energy CT in sacral fragility fractures: defining a cut-off Hounsfield unit value for the presence of traumatic bone marrow edema in patients with osteoporosis},
  series = {BMC Musculoskeletal Disorders},
  volume    = {23},
  journal   = {BMC Musculoskeletal Disorders},
  number    = {1},
  doi       = {10.1186/s12891-022-05690-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301125},
  year      = {2022},
  abstract  = {Background Demographic change entails an increasing incidence of fragility fractures. Dual-energy CT (DECT) with virtual non-calcium (VNCa) reconstructions has been introduced as a promising diagnostic method for evaluating bone microarchitecture and marrow simultaneously. This study aims to define the most accurate cut-off value in Hounsfield units (HU) for discriminating the presence and absence of bone marrow edema (BME) in sacral fragility fractures. Methods Forty-six patients (40 women, 6 men; 79.7 ± 9.2 years) with suspected fragility fractures of the sacrum underwent both DECT (90 kVp / 150 kVp with tin prefiltration) and MRI. Nine regions-of-interest were placed in each sacrum on DECT-VNCa images. The resulting 414 HU measurements were stratified into "edema" (n = 80) and "no edema" groups (n = 334) based on reference BME detection in T2-weighted MRI sequences. Area under the receiver operating characteristic curve was calculated to determine the desired cut-off value and an associated conspicuity range for edema detection. Results The mean density within the "edema" group of measurements (+ 3.1 ± 8.3 HU) was substantially higher compared to the "no edema" group (-51.7 ± 21.8 HU; p < 0.010). Analysis in DECT-VNCa images suggested a cut-off value of -12.9 HU that enabled sensitivity and specificity of 100\% for BME detection compared to MRI. A range of HU values between -14.0 and + 20.0 is considered indicative of BME in the sacrum. Conclusions Quantitative analysis of DECT-VNCa with a cut-off of -12.9 HU allows for excellent diagnostic accuracy in the assessment of sacral fragility fractures with associated BME. A diagnostic "one-stop-shop" approach without additional MRI is feasible.},
  language  = {en}
}
@article{PetritschPannbeckerWengetal.2021,
  author    = {Petritsch, Bernhard and Pannbecker, Pauline and Weng, Andreas M. and Grunz, Jan-Peter and Veldhoen, Simon and Bley, Thorsten A. and Kosmala, Aleksander},
  title     = {Split-filter dual-energy CT pulmonary angiography for the diagnosis of acute pulmonary embolism: a study on image quality and radiation dose},
  series = {Quantitative Imaging in Medicine and Surgery},
  volume    = {11},
  journal   = {Quantitative Imaging in Medicine and Surgery},
  number    = {5},
  doi       = {10.21037/qims-20-740},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231456},
  pages     = {1817-1827},
  year      = {2021},
  abstract  = {Background: Computed tomography (CT) pulmonary angiography is the diagnostic reference standard in suspected pulmonary embolism (PE). Favorable results for dual-energy CT (DECT) images have been reported for this condition. Nowadays, dual-energy data acquisition is feasible with different technical options, including a single-source split-filter approach. Therefore, the aim of this retrospective study was to investigate image quality and radiation dose of thoracic split-filter DECT in comparison to conventional single-energy CT in patients with suspected PE. Methods: A total of 110 CT pulmonary angiographies were accomplished either as standard single-energy CT with automatic tube voltage selection (ATVS) (n=58), or as split-filter DECT (n=52). Objective [pulmonary artery CT attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)] and subjective image quality [four-point Likert scale; three readers (R)] were compared among the two study groups. Size-specific dose estimates (SSDE), dose-length-product (DLP) and volume CT dose index (CTDIvol) were assessed for radiation dose analysis. Results: Split-filter DECT images yielded 67.7\% higher SNR (27.0 vs. 16.1; P<0.001) and 61.9\% higher CNR (22.5 vs. 13.9; P<0.001) over conventional single-energy images, whereas CT attenuation was significantly lower (344.5 vs. 428.2 HU; P=0.013). Subjective image quality was rated good or excellent in 93.0\%/98.3\%/77.6\% (R1/R2/R3) of the single-energy CT scans, and 84.6\%/82.7\%/80.8\% (R1/R2/R3) of the split-filter DECT scans. SSDE, DLP and CTDIvol were significantly lower for conventional single-energy CT compared to split-filter DECT (all P<0.05), which was associated with 26.7\% higher SSDE. Conclusions: In the diagnostic workup of acute PE, the split-filter allows for dual-energy data acquisition from single-source single-layer CT scanners. The existing opportunity to assess pulmonary "perfusion" based on analysis of iodine distribution maps is associated with higher radiation dose in terms of increased SSDE than conventional single-energy CT with ATVS. Moreover, a proportion of up to 3.8\% non-diagnostic examinations in the current reference standard test for PE is not negligible.},
  language  = {en}
}
@article{GietzenKunzLuetkensetal.2022,
  author    = {Gietzen, Carsten Herbert and Kunz, Andreas Steven and Luetkens, Karsten Sebastian and Huflage, Henner and Christopoulos, Georgios and van Schoonhoven, J{\"o}rg and Bley, Thorsten Alexander and Schmitt, Rainer and Grunz, Jan-Peter},
  title     = {Evaluation of prestyloid recess morphology and ulnar-sided contrast leakage in CT arthrography of the wrist},
  series = {BMC Musculoskeletal Disorders},
  volume    = {23},
  journal   = {BMC Musculoskeletal Disorders},
  number    = {1},
  doi       = {10.1186/s12891-022-05241-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301113},
  year      = {2022},
  abstract  = {Background In wrist arthrograms, aberrant contrast material is frequently seen extending into the soft tissue adjacent to the ulnar styloid process. Since the prestyloid recess can mimic contrast leakage in CT arthrography, this study aims to provide a detailed analysis of its morphologic variability, while investigating whether actual ulnar-sided leakage is associated with injuries of the triangular fibrocartilage complex (TFCC). Methods Eighty-six patients with positive wrist trauma history underwent multi-compartment CT arthrography (40 women, median age 44.5 years). Studies were reviewed by two board-certified radiologists, who documented the morphology of the prestyloid recess regarding size, opening type, shape and position, as well as the presence or absence of ulnar-sided contrast leakage. Correlations between leakage and the presence of TFCC injuries were assessed using the mean square contingency coefficient (r\(_{ɸ}\)). Results The most common configuration of the prestyloid recess included a narrow opening (73.26\%; width 2.26 ± 1.43 mm), saccular shape (66.28\%), and palmar position compared to the styloid process (55.81\%). Its mean length and anterior-posterior diameter were 6.89 ± 2.36 and 5.05 ± 1.97 mm, respectively. Ulnar-sided contrast leakage was reported in 29 patients (33.72\%) with a mean extent of 12.30 ± 5.31 mm. Leakage occurred more often in patients with ulnar-sided TFCC injuries (r\(_{ɸ}\) = 0.480; p < 0.001), whereas no association was found for lesions of the central articular disc (r\(_{ɸ}\) = 0.172; p = 0.111). Conclusions Since ulnar-sided contrast leakage is more common in patients with peripheral TFCC injuries, distinction between an atypical configuration of the prestyloid recess and actual leakage is important in CT arthrography of the wrist.},
  language  = {en}
}
@article{HuflageKunzHendeletal.2023,
  author    = {Huflage, Henner and Kunz, Andreas Steven and Hendel, Robin and Kraft, Johannes and Weick, Stefan and Razinskas, Gary and Sauer, Stephanie Tina and Pennig, Lenhard and Bley, Thorsten Alexander and Grunz, Jan-Peter},
  title     = {Obesity-related pitfalls of virtual versus true non-contrast imaging — an intraindividual comparison in 253 oncologic patients},
  series = {Diagnostics},
  volume    = {13},
  journal   = {Diagnostics},
  number    = {9},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics13091558},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313519},
  year      = {2023},
  abstract  = {Objectives: Dual-source dual-energy CT (DECT) facilitates reconstruction of virtual non-contrast images from contrast-enhanced scans within a limited field of view. This study evaluates the replacement of true non-contrast acquisition with virtual non-contrast reconstructions and investigates the limitations of dual-source DECT in obese patients. Materials and Methods: A total of 253 oncologic patients (153 women; age 64.5 ± 16.2 years; BMI 26.6 ± 5.1 kg/m\(^2\)) received both multi-phase single-energy CT (SECT) and DECT in sequential staging examinations with a third-generation dual-source scanner. Patients were allocated to one of three BMI clusters: non-obese: <25 kg/m\(^2\) (n = 110), pre-obese: 25-29.9 kg/m\(^2\) (n = 73), and obese: >30 kg/m\(^2\) (n = 70). Radiation dose and image quality were compared for each scan. DECT examinations were evaluated regarding liver coverage within the dual-energy field of view. Results: While arterial contrast phases in DECT were associated with a higher CTDI\(_{vol}\) than in SECT (11.1 vs. 8.1 mGy; p < 0.001), replacement of true with virtual non-contrast imaging resulted in a considerably lower overall dose-length product (312.6 vs. 475.3 mGy·cm; p < 0.001). The proportion of DLP variance predictable from patient BMI was substantial in DECT (R\(^2\) = 0.738) and SECT (R\(^2\) = 0.620); however, DLP of SECT showed a stronger increase in obese patients (p < 0.001). Incomplete coverage of the liver within the dual-energy field of view was most common in the obese subgroup (17.1\%) compared with non-obese (0\%) and pre-obese patients (4.1\%). Conclusion: DECT facilitates a 30.8\% dose reduction over SECT in abdominal oncologic staging examinations. Employing dual-source scanner architecture, the risk for incomplete liver coverage increases in obese patients.},
  language  = {en}
}
@article{HuflageGrunzPatzeretal.2023,
  author    = {Huflage, Henner and Grunz, Jan-Peter and Patzer, Theresa Sophie and Pannenbecker, Pauline and Feldle, Philipp and Sauer, Stephanie Tina and Petritsch, Bernhard and Erg{\"u}n, S{\"u}leyman and Bley, Thorsten Alexander and Kunz, Andreas Steven},
  title     = {Potential of unenhanced ultra-low-dose abdominal photon-counting CT with tin filtration: a cadaveric study},
  series = {Diagnostics},
  volume    = {13},
  journal   = {Diagnostics},
  number    = {4},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics13040603},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304122},
  year      = {2023},
  abstract  = {Objectives: This study investigated the feasibility and image quality of ultra-low-dose unenhanced abdominal CT using photon-counting detector technology and tin prefiltration. Materials and Methods: Employing a first-generation photon-counting CT scanner, eight cadaveric specimens were examined both with tin prefiltration (Sn 100 kVp) and polychromatic (120 kVp) scan protocols matched for radiation dose at three different levels: standard-dose (3 mGy), low-dose (1 mGy) and ultra-low-dose (0.5 mGy). Image quality was evaluated quantitatively by means of contrast-to-noise-ratios (CNR) with regions of interest placed in the renal cortex and subcutaneous fat. Additionally, three independent radiologists performed subjective evaluation of image quality. The intraclass correlation coefficient was calculated as a measure of interrater reliability. Results: Irrespective of scan mode, CNR in the renal cortex decreased with lower radiation dose. Despite similar mean energy of the applied x-ray spectrum, CNR was superior for Sn 100 kVp over 120 kVp at standard-dose (17.75 ± 3.51 vs. 14.13 ± 4.02), low-dose (13.99 ± 2.6 vs. 10.68 ± 2.17) and ultra-low-dose levels (8.88 ± 2.01 vs. 11.06 ± 1.74) (all p ≤ 0.05). Subjective image quality was highest for both standard-dose protocols (score 5; interquartile range 5-5). While no difference was ascertained between Sn 100 kVp and 120 kVp examinations at standard and low-dose levels, the subjective image quality of tin-filtered scans was superior to 120 kVp with ultra-low radiation dose (p < 0.05). An intraclass correlation coefficient of 0.844 (95\% confidence interval 0.763-0.906; p < 0.001) indicated good interrater reliability. Conclusions: Photon-counting detector CT permits excellent image quality in unenhanced abdominal CT with very low radiation dose. Employment of tin prefiltration at 100 kVp instead of polychromatic imaging at 120 kVp increases the image quality even further in the ultra-low-dose range of 0.5 mGy.},
  language  = {en}
}
@article{PatzerKunzHuflageetal.2023,
  author    = {Patzer, Theresa Sophie and Kunz, Andreas Steven and Huflage, Henner and Conrads, Nora and Luetkens, Karsten Sebastian and Pannenbecker, Pauline and Paul, Mila Marie and Erg{\"u}n, S{\"u}leyman and Bley, Thorsten Alexander and Grunz, Jan-Peter},
  title     = {Ultrahigh-resolution photon-counting CT in cadaveric fracture models: spatial frequency is not everything},
  series = {Diagnostics},
  volume    = {13},
  journal   = {Diagnostics},
  number    = {10},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics13101677},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319281},
  year      = {2023},
  abstract  = {In this study, the impact of reconstruction sharpness on the visualization of the appendicular skeleton in ultrahigh-resolution (UHR) photon-counting detector (PCD) CT was investigated. Sixteen cadaveric extremities (eight fractured) were examined with a standardized 120 kVp scan protocol (CTDI\(_{vol}\) 10 mGy). Images were reconstructed with the sharpest non-UHR kernel (Br76) and all available UHR kernels (Br80 to Br96). Seven radiologists evaluated image quality and fracture assessability. Interrater agreement was assessed with the intraclass correlation coefficient. For quantitative comparisons, signal-to-noise-ratios (SNRs) were calculated. Subjective image quality was best for Br84 (median 1, interquartile range 1-3; p ≤ 0.003). Regarding fracture assessability, no significant difference was ascertained between Br76, Br80 and Br84 (p > 0.999), with inferior ratings for all sharper kernels (p < 0.001). Interrater agreement for image quality (0.795, 0.732-0.848; p < 0.001) and fracture assessability (0.880; 0.842-0.911; p < 0.001) was good. SNR was highest for Br76 (3.4, 3.0-3.9) with no significant difference to Br80 and Br84 (p > 0.999). Br76 and Br80 produced higher SNRs than all kernels sharper than Br84 (p ≤ 0.026). In conclusion, PCD-CT reconstructions with a moderate UHR kernel offer superior image quality for visualizing the appendicular skeleton. Fracture assessability benefits from sharp non-UHR and moderate UHR kernels, while ultra-sharp reconstructions incur augmented image noise.},
  language  = {en}
}
@article{SchmidLoisMetzetal.2022,
  author    = {Schmid, Andrea and Lois, Anna-Maria and Metz, Corona and Grunz, Jan-Peter and Veldhoen, Simon},
  title     = {Not all that looks fractured is broken - multipartite humeral epicondyles in children},
  series = {European Radiology},
  volume    = {32},
  journal   = {European Radiology},
  number    = {8},
  doi       = {10.1007/s00330-022-08670-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324987},
  pages     = {5045-5052},
  year      = {2022},
  abstract  = {Objective Multipartite epicondyles may mimic fractures in the setting of pediatric elbow trauma. This study examines the prevalence of multipartite epicondyles during skeletal development and their association with pediatric elbow fractures. Materials and methods In this retrospective analysis, 4282 elbow radiographs of 1265 elbows of 1210 patients aged 0-17 years were reviewed. The radiographs were analyzed by two radiologists in consensus reading, and the number of visible portions of the medial and lateral epicondyles was noted. For elbows in which epicondylar ossification was not yet visible, the epicondyles were already fused with the humerus or could not be sufficiently evaluated due to projection issues or because osteosynthesis material was excluded. In total, 187 elbows were included for the lateral and 715 for the medial epicondyle analyses. Results No multipartite medial epicondyles were found in patients without history of elbow fracture, whereas 9\% of these patients had multipartite lateral epicondyles (p < 0.01). Current or previous elbow fractures increased the prevalence of multipartite epicondyles, with significant lateral predominance (medial epicondyle + 9\% vs. lateral + 24\%, p < 0.0001). Including all patients regardless of a history of elbow fracture, multipartite medial epicondyles were observed in 3\% and multipartite lateral epicondyles in 18\% (p < 0.0001). There was no gender difference in the prevalence of multipartition of either epicondyle, regardless of a trauma history. Conclusion Multipartite medial epicondyles occur in patients with current or previous elbow fractures only, whereas multipartite lateral epicondyles may be constitutional. Elbow fractures increase the prevalence of multipartite epicondyles on both sides, with significant lateral predominance. Key Points • Multipartite medial epicondyles should be considered of traumatic origin. • Multipartite lateral epicondyles may be constitutional. • Elbow fractures increase the prevalence of multipartite epicondyles on both sides with lateral predominance.},
  language  = {en}
}
@article{PennigHoyerKrauskopfetal.2021,
  author    = {Pennig, Lenhard and Hoyer, Ulrike Cornelia Isabel and Krauskopf, Alexandra and Shahzad, Rahil and J{\"u}nger, Stephanie T. and Thiele, Frank and Laukamp, Kai Roman and Grunz, Jan-Peter and Perkuhn, Michael and Schlamann, Marc and Kabbasch, Christoph and Borggrefe, Jan and Goertz, Lukas},
  title     = {Deep learning assistance increases the detection sensitivity of radiologists for secondary intracranial aneurysms in subarachnoid hemorrhage},
  series = {Neuroradiology},
  volume    = {63},
  journal   = {Neuroradiology},
  number    = {12},
  issn      = {0028-3940},
  doi       = {10.1007/s00234-021-02697-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308117},
  pages     = {1985-1994},
  year      = {2021},
  abstract  = {Purpose To evaluate whether a deep learning model (DLM) could increase the detection sensitivity of radiologists for intracranial aneurysms on CT angiography (CTA) in aneurysmal subarachnoid hemorrhage (aSAH). Methods Three different DLMs were trained on CTA datasets of 68 aSAH patients with 79 aneurysms with their outputs being combined applying ensemble learning (DLM-Ens). The DLM-Ens was evaluated on an independent test set of 104 aSAH patients with 126 aneuryms (mean volume 129.2 ± 185.4 mm3, 13.0\% at the posterior circulation), which were determined by two radiologists and one neurosurgeon in consensus using CTA and digital subtraction angiography scans. CTA scans of the test set were then presented to three blinded radiologists (reader 1: 13, reader 2: 4, and reader 3: 3 years of experience in diagnostic neuroradiology), who assessed them individually for aneurysms. Detection sensitivities for aneurysms of the readers with and without the assistance of the DLM were compared. Results In the test set, the detection sensitivity of the DLM-Ens (85.7\%) was comparable to the radiologists (reader 1: 91.2\%, reader 2: 86.5\%, and reader 3: 86.5\%; Fleiss κ of 0.502). DLM-assistance significantly increased the detection sensitivity (reader 1: 97.6\%, reader 2: 97.6\%,and reader 3: 96.0\%; overall P=.024; Fleiss κ of 0.878), especially for secondary aneurysms (88.2\% of the additional aneurysms provided by the DLM). Conclusion Deep learning significantly improved the detection sensitivity of radiologists for aneurysms in aSAH, especially for secondary aneurysms. It therefore represents a valuable adjunct for physicians to establish an accurate diagnosis in order to optimize patient treatment.},
  language  = {en}
}