(2025) Braaksma | Pediatric abdomen PCCT protocol development

Daniel Stromer

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