The study demonstrates that ultra-high-pitch PCCT can enable reliable diagnosis of acute pulmonary embolism even under free-breathing conditions.
Using a low contrast volume and fast acquisition, the protocol achieves superior image quality while simultaneously reducing radiation dose compared to conventional CT.
The approach highlights PCCT’s potential to simplify thoracic emergency workflows by combining robustness, speed, and diagnostic confidence in a single protocol.
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Figure 4 Axial (a) ultra-high-pitch PCD-CTPA at 60 keV of a 45-year-old woman demonstrating pulmonary embolism in the left upper lobe (arrow) with corresponding wedge-shaped perfusion deficits in the iodine maps (b and c; arrowheads). Anatomical CTPA and iodine maps were considered excellent by all three readers. CTPA, CT pulmonary angiography; PCD, photon-counting detector.
Source: Pannenbecker et al., Academic Radiology, 2024. Licensed under CC BY 4.0.
Protocol
Scanner | NAEOTOM Alpha |
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Scan area | Thorax (pulmonary angiography) |
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Scan mode | Quantum HD Ultra-high-pitch spiral |
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Scan direction | Craniocaudal |
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Tube voltage [kV] | 140 |
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Effective mAs [mAs] | n.a. |
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IQ level | 50 |
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Dose modulation | Automatic exposure control |
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CTDIvol [mGy] | 2.3 ( ± 0.7) in cohort |
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DLP [mGy*cm] | 73.9 ( ± 26.3) in cohort |
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Rotation time [s] | 0.25 |
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Pitch | 3.2 |
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Matrix | 512 |
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Slice collimation [mm] | 120 x 0.2 |
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Slice width [mm] | 3 |
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Reconstruction increment [mm] | n.a. |
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Reconstruction kernel | Bv36 |
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KeV level [keV] | 60 |
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Spectral reconstruction | Iodine maps, VMI |
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Contrast | Iodine |
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Volume [mL] | 40 |
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Flow rate [mL/s] | 3 |
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Pannenbecker P et al. The Best of Both Worlds: Ultra-high-pitch Pulmonary Angiography with Free-Breathing Technique by Means of Photon-Counting Detector CT for Diagnosis of Acute Pulmonary Embolism. Academic Radiology, 2024; 31, 5280-5288.
