Simulated low-dose computed tomography in oncological patients: a feasibility study

Area of Science:

• Radiology
• Medical Imaging
• Oncology

Background:

• Computed tomography (CT) is crucial for staging and follow-up of oncological patients.
• Optimizing radiation dose while maintaining diagnostic image quality is a key challenge in CT imaging.
• Multislice CT (MSCT) offers advanced imaging capabilities but requires careful dose management.

Purpose of the Study:

• To evaluate the image quality of chest and abdominal CT scans at various radiation doses.
• To determine the lowest X-ray dose at which image quality remains unaffected for oncological patient follow-up.

Main Methods:

• Utilized multislice CT (MSCT) on 29 patients undergoing follow-up examinations.
• Simulated five different dose levels by adding milliampere second-dependent noise to raw data.
• Two radiologists assessed image quality using a 1-to-5-point scale, analyzing noise, lesion detection, contour, and contrast.

Main Results:

• Image noise significantly changed between 40 and 60 mA s, with noise increasing significantly at 40 mA s.
• Lesion detection and contour of small objects were not significantly affected by dose reductions to 40 mA s.
• Contrast remained unaffected until a maximal dose reduction to 20 mA s.

Conclusions:

• Multislice CT (MSCT) allows for lower radiation doses than currently used for adequate follow-up and staging of oncological patients.
• Dose reduction strategies can be implemented without significant compromise to essential diagnostic parameters like contrast and lesion detectability.