For routine pediatric abdomen PCCT, start with Quantum mode at 70 kV and low-keV VMI rather than defaulting to QuantumPlus. Based on their phantom work, the authors favor the lowest tube voltage as the ALARA-oriented starting point, and for their standard protocol they selected 70 kV Quantum mode with VMI 53 keV.
Optimize image quality first through reconstruction settings before increasing acquisition dose. The authors recommend first adjusting QIR strength, kernel choice, and windowing if noise is too high, and only then considering higher IQ level, DAC changes, or QuantumPlus mode.
Use high-pitch FLASH selectively, not routinely. The authors found FLASH shortened scan time but slightly increased noise and dose, so they recommend it mainly for children who cannot hold their breath long enough for a standard scan.
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Figure 5. Examples of the clinical implementation of the pediatric abdomen protocol. Axial computed tomography slices in the portal venous phase after intravenous contrast demonstrate the appearances of contrast and noise of the protocol at different ages. Protocol: 70 kV Quantum mode at 53 keV virtual monoenergetic image, IQ level 120, body reconstruction kernel 40, quantum iterative reconstruction 2, 1.0-mm slice thickness. a Six-month-old girl after liver transplantation. b Two-year-old girl prior to liver transplantation. c Six-year-old boy after liver transplantation
Source note for image: Braaksma et al., Pediatric Radiology, 2025.
Standard Protocol
Parameter | |
|---|
Scanner | NAEOTOM Alpha |
|---|
Scan mode | Quantum |
|---|
Siemens protocol | RoutineFlashSpiralChildAbdomenQuantum |
|---|
Tube voltage, kV | 70/90 |
|---|
Number of slices, mm | 144 × 0.4 |
|---|
Z-coverage, mm | 58 |
|---|
Rotation time, s | 0.25 |
|---|
IQ level | 120 |
|---|
Pitch | 3.2 (FLASH) or 1.5 |
|---|
Care keV | On |
|---|
CARE Dose4D | On |
|---|
Dose adaption curve | Average |
|---|
Tissue of interest setting | Soft tissue with contrast |
|---|
Reconstruction parameters | |
|---|
Reconstructed slice thickness, mm | 1.0 and 3.0 (0.6 and 2.0 increment) |
|---|
Matrix | Auto |
|---|
VMI, keV | 53 |
|---|
Kernels | Br40 (1 mm), Br40 (3 mm) |
|---|
QIR | 2 |
|---|
Window level / window width | 55 / 335 |
|---|
Spectral analysis | No |
|---|
Intravenous iodine contrast | |
|---|
Contrast phase | Portal venous, delay is age dependent |
|---|
Volume and flow rate | Age and kV dependent |
|---|
Complex Protocol (not used clinically, optimized for noise & thinner slices)
Parameter | Value |
|---|
Scanner | NAEOTOM Alpha |
|---|
Scan mode | QuantumPlus |
|---|
Siemens protocol | RoutineFlashSpiralChildAbdomenQuantumplus |
|---|
Tube voltage, kV | 120/140 |
|---|
Number of slices, mm | 144 × 0.4 |
|---|
Z-coverage, mm | 58 |
|---|
Rotation time, s | 0.25 |
|---|
IQ level | 120 |
|---|
Pitch | 3.2 (FLASH) or 1.5 |
|---|
Care keV | On |
|---|
CARE Dose4D | On |
|---|
Dose adaption curve | Average |
|---|
Tissue of interest setting | Soft tissue with contrast |
|---|
Reconstruction parameters | |
|---|
Reconstructed slice thickness, mm | 0.4, 1.0 and 3.0 (0.3, 0.6 and 2.0 increment) |
|---|
Matrix | Auto |
|---|
VMI, keV | 53 (T3D for non-contrast if needed) |
|---|
Kernels | Br40 (1 mm), Br40 (3 mm), Bv60 (0.4, 1 mm) |
|---|
QIR | 2 |
|---|
Window level / window width | 55 / 335 |
|---|
Spectral analysis | Iodine map, virtual non-contrast |
|---|
Intravenous iodine contrast | |
|---|
Contrast phase | Portal venous, delay is age dependent |
|---|
Volume and flow rate | Age and kV dependent |
|---|
Full citation:
Braaksma J, Greuter MJW, Verhagen MV. Physics and rationale in pediatric abdomen photon counting detector computed tomography: an investigative review towards development of a pediatric abdomen protocol. Pediatr Radiol. 2025;55:1556–1567. doi:10.1007/s00247-025-06274-7
