TY  - JOUR
A1  - Patzer, Theresa Sophie
A1  - Kunz, Andreas Steven
A1  - Huflage, Henner
A1  - Conrads, Nora
A1  - Luetkens, Karsten Sebastian
A1  - Pannenbecker, Pauline
A1  - Paul, Mila Marie
A1  - Ergün, Süleyman
A1  - Bley, Thorsten Alexander
A1  - Grunz, Jan-Peter
T1  - Ultrahigh-resolution photon-counting CT in cadaveric fracture models: spatial frequency is not everything
JF  - Diagnostics
N2  - 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.
KW  - photon-counting
KW  - tomography
KW  - X-ray computed
KW  - fracture
KW  - cancellous bone
KW  - convolution kernel
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319281
SN  - 2075-4418
VL  - 13
IS  - 10
ER  - 
TY  - JOUR
A1  - Grunz, Jan-Peter
A1  - Gietzen, Carsten Herbert
A1  - Luetkens, Karsten
A1  - Wagner, Matthias
A1  - Kalb, Karlheinz
A1  - Bley, Thorsten Alexander
A1  - Lehmkul, Luka
A1  - van Schoonhoven, Jörg
A1  - Gassenmaier, Tobias
A1  - Schmitt, Rainer
T1  - The importance of radial multiplanar reconstructions for assessment of triangular fibrocartilage complex injury in CT arthrography of the wrist
JF  - BMC Musculoskeletal Disorders
N2  - 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.
KW  - Triangular fibrocartilage
KW  - Wrist
KW  - Arthrography
KW  - Tomography
KW  - X-ray computed
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236075
VL  - 21
ER  -