OBJECTIVE: The objective of this study was to determine if spiral CT with 4-mm interscan spacing results in increased confidence in or rate of detection of focal hepatic lesions when compared with spiral CT with 8-mm interscan spacing. MATERIALS AND METHODS: Spiral CT scans of the liver of 42 consecutive patients with suspected hepatic disease were independently reviewed by three senior radiologists in two sets: one set was reconstructed with 8-mm interscan spacing and one set was reconstructed with 4-mm interscan spacing. The slice thickness was 8 mm for both data sets. The number and sizes of focal hepatic lesions were documented. RESULTS: Thirty-three of the 42 patients had least one focal lesion. The lesion size varied from 2 mm to 21 cm. When 8-mm interscan spacing was used, 297 lesions were detected (212 were considered definite). When 4-mm interscan spacing was used, 318 lesions were detected (258 were considered definite). Therefore, 7% more lesions were detected with 4-mm interscan spacing than with 8-mm interscan spacing (p = .05), and 22% more were diagnosed definitively (p < .01). If lesions larger than 4 cm are excluded, 10% more lesions were detected with 4-mm interscan spacing, and 33% more were diagnosed definitively. Of the lesions detected exclusively with 4-mm interscan spacing, 69% were less than 1.0 cm in diameter. CONCLUSION: Spiral CT with smaller interscan spacing (4 instead of 8 mm) results in increased confidence in and rate of detection of focal liver lesions. The additional benefit is most significant with smaller lesions.
OBJECTIVE: The objective of this study was to determine if spiral CT with 4-mm interscan spacing results in increased confidence in or rate of detection of focal hepatic lesions when compared with spiral CT with 8-mm interscan spacing. MATERIALS AND METHODS: Spiral CT scans of the liver of 42 consecutive patients with suspected hepatic disease were independently reviewed by three senior radiologists in two sets: one set was reconstructed with 8-mm interscan spacing and one set was reconstructed with 4-mm interscan spacing. The slice thickness was 8 mm for both data sets. The number and sizes of focal hepatic lesions were documented. RESULTS: Thirty-three of the 42 patients had least one focal lesion. The lesion size varied from 2 mm to 21 cm. When 8-mm interscan spacing was used, 297 lesions were detected (212 were considered definite). When 4-mm interscan spacing was used, 318 lesions were detected (258 were considered definite). Therefore, 7% more lesions were detected with 4-mm interscan spacing than with 8-mm interscan spacing (p = .05), and 22% more were diagnosed definitively (p < .01). If lesions larger than 4 cm are excluded, 10% more lesions were detected with 4-mm interscan spacing, and 33% more were diagnosed definitively. Of the lesions detected exclusively with 4-mm interscan spacing, 69% were less than 1.0 cm in diameter. CONCLUSION: Spiral CT with smaller interscan spacing (4 instead of 8 mm) results in increased confidence in and rate of detection of focal liver lesions. The additional benefit is most significant with smaller lesions.
Authors: Yunjie Song; Jonathan Skinner; Julie Bynum; Jason Sutherland; John E Wennberg; Elliott S Fisher Journal: N Engl J Med Date: 2010-05-12 Impact factor: 91.245