(2023) Niehoff | Low-dose PCCT detects urolithiasis with less dose by maintaining image quality

Daniel Stromer

Lowering the PCCT image quality level from 70 to 50 reduced radiation dose significantly, with SSDE decreasing by 22.8%, without materially compromising image quality.

Stone detection remained high across protocols, with detection rates of 91.3% to 100%, while diagnostic confidence stayed consistently high and unaffected by dose reduction.

Quantitative and qualitative image quality changed only minimally despite lower dose, and ureter stone size measurements remained highly reproducible across all settings.

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Figure 4. Examples of ureter stones that were included in the analysis of the stone size measurements. CT scans were performed with image quality levels (IQLs) 70 (A), 60 (B) and 50 (C).

Source: Niehoff et al., Diagnostics, 2023

Protocol

Detail	Value
Scanner	NAEOTOM Alpha
Scan type	Non-contrast low-dose Abdomen
Scan mode	Quantum Sn
Tube voltage [kVp]	100 with tin filter
Detector configuration	144 × 0.4 mm
Pitch	0.6
Rotation time [s]	0.5
Reconstruction kernel	Br36
QIR	Q4
Slice thickness / increment [mm]	2 / 1
Matrix	512 × 512
Compared protocols	IQ 70 (n=31) IQL60 (n=31) IQL50 (n=36)
Size-specific dose estimate SSDE	4.57 ± 0.84 mGy at IQL70 3.53 ± 0.70 mGy at IQL50
Effective dose	2.43 ± 0.99 mSv at IQL70 1.97 ± 0.72 mSv at IQL50

Niehoff JH, Carmichael AF, Woeltjen MM, et al. Clinical Low-Dose Photon-Counting CT for the Detection of Urolithiasis: Radiation Dose Reduction Is Possible without Compromising Image Quality. Diagnostics. 2023;13(3):458.