Intra-patient comparison of reduced-dose model-based iterative reconstruction with standard-dose adaptive statistical iterative reconstruction in the CT diagnosis and follow-up of urolithiasis

To evaluate the accuracy of reduced-dose CT scans reconstructed using a new generation of model-based iterative reconstruction (MBIR) in the imaging of urinary tract stone disease, compared with a standard-dose CT using 30% adaptive statistical iterative reconstruction.

This single-institution prospective study recruited 125 patients presenting either with acute renal colic or for follow-up of known urinary tract stones. They underwent two immediately consecutive scans, one at standard dose settings and one at the lowest dose (highest noise index) the scanner would allow. The reduced-dose scans were reconstructed using both ASIR 30% and MBIR algorithms and reviewed independently by two radiologists. Objective and subjective image quality measures as well as diagnostic data were obtained.

The reduced-dose MBIR scan was 100% concordant with the reference standard for the assessment of ureteric stones. It was extremely accurate at identifying calculi of 3 mm and above. The algorithm allowed a dose reduction of 58% without any loss of scan quality.

A reduced-dose CT scan using MBIR is accurate in acute imaging for renal colic symptoms and for urolithiasis follow-up and allows a significant reduction in dose.

• MBIR allows reduced CT dose with similar diagnostic accuracy • MBIR outperforms ASIR when used for the reconstruction of reduced-dose scans • MBIR can be used to accurately assess stones 3 mm and above.

European radiology. 2017 Mar 13 [Epub ahead of print]

Sean Tenant, Chun Lap Pang, Prageeth Dissanayake, Varut Vardhanabhuti, Colin Stuckey, Catherine Gutteridge, Christopher Hyde, Carl Roobottom

Peninsula Radiology Academy, William Prance Rd, Plymouth, PL6 5WR, UK. ., Peninsula Radiology Academy, William Prance Rd, Plymouth, PL6 5WR, UK., Plymouth University Peninsula Schools of Medicine and Dentistry, John Bull Building, Plymouth, PL6 8BU, UK., Plymouth Hospitals NHS Trust, Derriford Rd, Plymouth, PL6 8DH, UK., University of Exeter Medical School, St Luke's Campus, Heavitree Road, Exeter, EX1 2LU, UK.