Digital tomosynthesis in the detection of urolithiasis: Diagnostic performance and dosimetry compared with digital radiography with MDCT as the reference standard.
OBJECTIVE
The purpose of this study was to evaluate the diagnostic performance of digital tomosynthesis in comparison with digital radiography in the detection of urinary stones with MDCT as the reference standard.


METHODS
Fifty consecutively enrolled patients (32 men, 18 women; mean age, 51.5 years; range, 19-83 years) referred for unenhanced MDCT of the abdomen with suspicion of urinary stones also underwent digital tomosynthesis and digital radiography (anteroposterior and bladder inlet views). Images from all examinations were randomly read by three blinded radiologists. The mean effective doses for digital tomosynthesis, digital radiography, and low- and high-dose MDCT were measured on a male phantom. Free-response receiver operating characteristics and receiver operating characteristics analyses were used to compare the diagnostic performance of digital radiography with that of digital tomosynthesis.


RESULTS
Both types of analysis showed significantly better performance of tomosynthesis over digital radiography for all urinary stones (p < 0.05). No such improvement was found for ureteral stones. The gain in sensitivity with tomosynthesis was largest for stones between 2 and 5 mm in diameter. The mean effective dose was 0.5 mSv for digital radiography, 0.85 mSv for tomosynthesis, 2.5 mSv for low-dose MDCT, and 12.6 mSv for high-dose MDCT.


CONCLUSIONS
Use of digital tomosynthesis of the abdomen results in improved detection of urinary stones in general over digital radiography with only a slight increase in effective dose. Use of tomosynthesis, however, was not associated with major improvement in the diagnosis of ureteral stones. The technique has potential as an alternative imaging technique in the detection and follow-up of urinary stones.
Mermuys
Koen
K
Department of Radiology, A.Z. St.-Jan Hospital, Brugge, Belgium. koen.mermuys@azbrugge.be <koen.mermuys@azbrugge.be>
De Geeter
Frank
F
Bacher
Klaus
K
Van De Moortele
Kris
K
Coenegrachts
Kenneth
K
Steyaert
Luc
L
Casselman
Jan W
JW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D019047:Phantoms, Imaging; D011446:Prospective Studies; D012372:ROC Curve; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D036542:Tomography, Spiral Computed / Q000379:methods*; D052878:Urolithiasis / Q000000981:diagnostic imaging*