16-MDCT in the detection of occult wrist fractures: a comparison with skeletal scintigraphy.
OBJECTIVE
Our objective was to assess the potential use of MDCT in the detection of occult scaphoid fractures. Fifty-one patients with suspected radiographically occult scaphoid fractures at 10-14 days after trauma were investigated prospectively with skeletal scintigraphy and CT on the same day. Planar images of the wrist were taken 3 hr after IV injection of 400 MBq of (99m)Tc-methylene diphosphonate using a single-head gamma camera. CT was performed on a 16-MDCT machine using 0.75-mm detectors and reconstruction in 0.5-mm slices. Multiplanar reformatted images were then viewed in interactive cine mode. The examinations were reported independently, and discordant results were compared at follow-up. CT was positive for wrist fracture in 14 (27.4%) of 51 patients and skeletal scintigraphy in 23 (45.1%) of 51 patients. Even after retrospective review, there were seven discrepant cases (13.7%), all of which were positive for wrist fracture on scintigraphy but negative on CT. Four of these seven patients with discordant findings underwent further radiography at 6 weeks, which did not show fracture.


CONCLUSIONS
Although CT was preferred by most patients and was quicker, scintigraphy appears to detect bony abnormality more frequently. However, there appears to be an interesting group of patients (7/51) with normal initial radiography findings but positive scintigraphy findings who would normally be considered to have a fracture but for whom CT results were negative. In some of these patients, the results of follow-up radiography at 6 weeks were also negative, suggesting that this group of patients warrants further study.
Groves
Ashley M
AM
Department of Radiology, Addenbrooke's Hospital NHS Trust and the University of Cambridge, Box 218, Hills Rd, Cambridge CB2 2QQ, England.
Cheow
Heok
H
Balan
Kottekkattu
K
Courtney
Helen
H
Bearcroft
Philip
P
Dixon
Adrian
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D021361:Scaphoid Bone / Q000000981:diagnostic imaging / Q000293:injuries*; D013669:Technetium Tc 99m Medronate; D014057:Tomography, X-Ray Computed; D014954:Wrist Injuries / Q000000981:diagnostic imaging*
D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate