American Journal of Roentgenology, Vol 169, 555-561, Copyright © 1997 by American Roentgen Ray Society
Soft-copy versus hard-copy cranial sonography: intraobserver agreement and workstation efficiency
S Don, GG Reiker, C Hildebolt, GD Shackelford, WH McAlister, R Ryerson, GJ Blaine and MJ Siegel
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
OBJECTIVE: The objective of the study was to determine the intraobserver
agreement, confidence level, and efficiency in interpretation of soft-copy
(workstation) versus hard-copy (laser- printed film) sonograms of the
cranium. MATERIALS AND METHODS: Cranial sonograms of 100 premature infants
were randomly reviewed twice on both soft-copy and hard-copy images by
three observers and were graded for hemorrhage using a five-level scale.
The kappa statistic was calculated to measure intraobserver agreement.
Differences in agreement were tested for statistical significance with a
test for marginal homogeneity. Observers rated their confidence in
interpretation using a six-point ordinal scale. Total viewing time was
recorded, and videotaped sessions were analyzed for image handling time
(opening each case, closing each case, and selecting the next case) and
interpretation time. RESULTS: For soft copy versus hard copy, the mean
kappa value was .73; for hard-copy 1 versus hard-copy 2, .71; and for
soft-copy 1 versus soft-copy 2, .65. None of these differences was
statistically significant (p > .05). The mean confidence score was the
same for soft copy (5.3) and hard copy (5.3). On average, the observers
needed 24 min longer to review 100 studies on soft copy than on hard copy.
Opening and closing times for soft copy were significantly faster than for
hard copy (p = .0001); however, case selection for soft copy, which was not
needed for hard copy, took 4.69-9.09 sec per case. Extrapolated to 100
cases, case selection accounted for 8-15 min of viewing time. CONCLUSION:
Radiologist agreement and confidence in the interpretation of cranial
sonograms for hemorrhage was the same for soft copy and hard copy. However,
viewing times were longer for soft copy. Elimination of inefficiency in
case selection could improve image- handling time.