Low-dose and standard computed tomography scans yield equivalent stone measurements

Area of Science:

• Radiology
• Medical Imaging
• Nephrology

Background:

• Kidney stones (nephrolithiasis) are a common condition requiring accurate imaging for diagnosis and management.
• Computed tomography (CT) is a primary imaging modality for kidney stones, but concerns exist regarding radiation dose.
• Low-dose CT protocols are being explored to minimize radiation exposure while maintaining diagnostic efficacy.

Purpose of the Study:

• To compare the reliability of low-dose CT versus standard-dose CT in assessing key stone characteristics.
• To evaluate the accuracy of low-dose CT for measuring stone size, density (Hounsfield units), and skin-to-stone distance (SSD).

Main Methods:

• A prospective study involving 10 patients with kidney stones who underwent both conventional and low-dose CT scans.
• Standardized 2-mm slice thickness and 3D reconstructions were used for both scan types.
• Measurements included stone dimensions (height, width, length), Hounsfield units, and SSD.

Main Results:

• No statistically significant differences were observed in stone size (P > .5 for all dimensions) or Hounsfield units (P = .6) between low-dose and conventional CT.
• Skin-to-stone distance measurements also showed no significant difference (P = .5).
• Low-dose CT achieved an average effective radiation dose reduction of 73% (from 23 to 6 mSv).

Conclusions:

• Low-dose CT is a reliable alternative to conventional CT for evaluating kidney stone size, density, and SSD.
• The use of low-dose CT significantly reduces patient radiation exposure without sacrificing diagnostic accuracy.
• This finding supports the wider adoption of low-dose CT protocols in kidney stone imaging.