TY - JOUR
T1 - High-Pitch Photon-Counting Detector Computed Tomography Angiography of the Aorta Intraindividual Comparison to Energy-Integrating Detector Computed Tomography at Equal Radiation Dose
AU - Euler, Andre
AU - Higashigaito, Kai
AU - Mergen, Victor
AU - Sartoretti, Thomas
AU - Zanini, Bettina
AU - Schmidt, Bernhard
AU - Flohr, Thomas G.
AU - Ulzheimer, Stefan
AU - Eberhard, Matthias
AU - Alkadhi, Hatem
PY - 2022/2/1
Y1 - 2022/2/1
N2 - Purpose: The aims of this study were to determine the objective and subjective image quality of high-pitch computed tomography (CT) angiography of the aorta in clinical dual-source photon-counting detector CT (PCD-CT) and to compare the image quality to conventional dual-source energy-integrating detector CT (EID-CT) in the same patients at equal radiation dose. Materials andMethods: Patients with priorCTangiography of the thoracoabdominal aorta acquired on third-generation dual-source EID-CT in the high-pitchmode and with automatic tube voltage selection (ATVS, reference tube voltage 100 kV) were included. Follow-up imaging was performed on a first-generation, clinical dual-source PCD-CT scanner in the high-pitch and multienergy (QuantumPlus) mode at 120 kV using the same contrast media protocol as with EID-CT. Radiation doses between scans were matched by adapting the tube current of PCD-CT. Polychromatic images for both EID-CT and PCD-CT (called T3D) and virtual monoenergetic images at 40, 45, 50, and 55 keV for PCD-CTwere reconstructed. Computed tomography attenuation was measured in the aorta; noise was defined as the standard deviation of attenuation; contrast-to-noise ratio (CNR) was calculated. Subjective image quality (noise, vessel attenuation, vessel sharpness, and overall quality) was rated by 2 blinded, independent radiologists. Results: Forty patients were included (mean age, 63 years; 8 women; mean body mass index [BMI], 26 kg/m(2)). There was no significant difference in BMI, effective diameter, or radiation dose between scans (all P's > 0.05). The ATVS in EID-CT selected 70, 80, 90, 100, 110, and 120 kV in 2, 14, 14, 7, 2, and 1 patients, respectively. Mean CNR was 17 +/- 8 for EID-CT and 22 +/- 7, 20 +/- 6, 18 +/- 5, 16 +/- 5, and 12 +/- 4 for PCD-CT at 40, 45, 50, 55 keV, and T3D, respectively. Contrast-to-noise ratio was significantly higher for 40 and 45 keV of PCD-CT as compared with EID-CT (both P's < 0.05). The linear regression model (adjusted R-2, 0.38; P < 0.001) revealed that PCD-CT reconstruction (P < 0.001), BMI group (P = 0.007), and kVof the EID-CT scan (P = 0.01) were significantly associated with CNR difference, with an increase by 34% with PCD-CT for overweight as compared with normal weight patients. Subjective image quality reading revealed slight differences between readers for subjective vessel attenuation and sharpness, whereas subjective noise was rated significantly higher for 40 and 45 keV (P < 0.001) and overall quality similar (P > 0.05) between scans. Conclusions: High-pitch PCD-CT angiography of the aorta with VMI at 40 and 45 keV resulted in significantly increased CNR compared with EID-CT with ATVS at matched radiation dose. The CNR gain of PCD-CT increased in overweight patients. Taking into account the subjective analysis, VMI at 45 to 50 keV is proposed as the best trade-off between objective and subjective image quality.
AB - Purpose: The aims of this study were to determine the objective and subjective image quality of high-pitch computed tomography (CT) angiography of the aorta in clinical dual-source photon-counting detector CT (PCD-CT) and to compare the image quality to conventional dual-source energy-integrating detector CT (EID-CT) in the same patients at equal radiation dose. Materials andMethods: Patients with priorCTangiography of the thoracoabdominal aorta acquired on third-generation dual-source EID-CT in the high-pitchmode and with automatic tube voltage selection (ATVS, reference tube voltage 100 kV) were included. Follow-up imaging was performed on a first-generation, clinical dual-source PCD-CT scanner in the high-pitch and multienergy (QuantumPlus) mode at 120 kV using the same contrast media protocol as with EID-CT. Radiation doses between scans were matched by adapting the tube current of PCD-CT. Polychromatic images for both EID-CT and PCD-CT (called T3D) and virtual monoenergetic images at 40, 45, 50, and 55 keV for PCD-CTwere reconstructed. Computed tomography attenuation was measured in the aorta; noise was defined as the standard deviation of attenuation; contrast-to-noise ratio (CNR) was calculated. Subjective image quality (noise, vessel attenuation, vessel sharpness, and overall quality) was rated by 2 blinded, independent radiologists. Results: Forty patients were included (mean age, 63 years; 8 women; mean body mass index [BMI], 26 kg/m(2)). There was no significant difference in BMI, effective diameter, or radiation dose between scans (all P's > 0.05). The ATVS in EID-CT selected 70, 80, 90, 100, 110, and 120 kV in 2, 14, 14, 7, 2, and 1 patients, respectively. Mean CNR was 17 +/- 8 for EID-CT and 22 +/- 7, 20 +/- 6, 18 +/- 5, 16 +/- 5, and 12 +/- 4 for PCD-CT at 40, 45, 50, 55 keV, and T3D, respectively. Contrast-to-noise ratio was significantly higher for 40 and 45 keV of PCD-CT as compared with EID-CT (both P's < 0.05). The linear regression model (adjusted R-2, 0.38; P < 0.001) revealed that PCD-CT reconstruction (P < 0.001), BMI group (P = 0.007), and kVof the EID-CT scan (P = 0.01) were significantly associated with CNR difference, with an increase by 34% with PCD-CT for overweight as compared with normal weight patients. Subjective image quality reading revealed slight differences between readers for subjective vessel attenuation and sharpness, whereas subjective noise was rated significantly higher for 40 and 45 keV (P < 0.001) and overall quality similar (P > 0.05) between scans. Conclusions: High-pitch PCD-CT angiography of the aorta with VMI at 40 and 45 keV resulted in significantly increased CNR compared with EID-CT with ATVS at matched radiation dose. The CNR gain of PCD-CT increased in overweight patients. Taking into account the subjective analysis, VMI at 45 to 50 keV is proposed as the best trade-off between objective and subjective image quality.
KW - photon-counting CT
KW - multienergy
KW - CT angiography
KW - virtual monoenergetic imaging
KW - aorta
KW - image quality
KW - radiation dose
KW - TUBE POTENTIAL SELECTION
KW - DUAL-SOURCE CT
KW - IMAGE-QUALITY
KW - KEV-SETTINGS
KW - NOISE
KW - RECONSTRUCTION
KW - IODINE
KW - OPTIMIZATION
KW - AORTOGRAPHY
KW - MDCT
U2 - 10.1097/RLI.0000000000000816
DO - 10.1097/RLI.0000000000000816
M3 - Article
C2 - 34352805
SN - 0020-9996
VL - 57
SP - 115
EP - 121
JO - Investigative Radiology
JF - Investigative Radiology
IS - 2
ER -