16 detector multislice CT versus skeletal scintigraphy in the diagnosis of wrist fractures: value of quantification of 99Tcm-MDP uptake.
To compare the measured uptake of 99Tcm-methylene diphosphonate (99Tcm-MDP) in those scaphoid fractures seen on both 16 detector multislice CT and scintigraphy, with those seen only on scintigraphy. Over a 12 month period a total of 51 patients with suspected fracture underwent both conventional 99Tcm-MDP scintigraphy and 16 detector multislice CT on the same day. The 99Tcm-MDP uptake was then quantified in patients with identified fracture. This was measured by placing a region of interest (ROI) over the fracture site and the mean and maximum number of counts were compared with those in a similar size ROI placed over background bone activity. A total of 23 fractures were identified on scintigraphy of which 16 were also detected on CT (concordant). In seven cases the fracture was not seen on CT, even in retrospect (discordant). In the discordant cases, follow-up radiographs and MRI (where available) also failed to demonstrate a fracture. The mean fracture count to background bone activity ratio averaged 7.7 (range 3.2-18.5) for concordant fractures and 3.8 (range 1.7-5.3) for discordant fractures (t-test p=0.04). The maximum fracture count to background bone activity ratio averaged 12.7 (range 4.3-27.7) for concordant fractures and 6.3 (range 2.6-9.5) for discordant fractures (t-test p=0.03). It is speculated whether these discordant fractures with less 99Tcm-MDP uptake may represent a less severe injury such as bone bruise.
Groves
A M
AM
Department of Radiology, Addenbrooke's Hospital NHS Trust and the University of Cambridge, Hills Road, Cambridge CB2 2QQ, UK.
Cheow
H K
HK
Balan
K K
KK
Bearcroft
P W P
PW
Dixon
A K
AK
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; 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 / Q000379:methods; D014954:Wrist Injuries / Q000000981:diagnostic imaging*
D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate