[Diagnosis and classification of calcaneal fractures in computed tomography].
OBJECTIVE
To compare image quality of single-slice spiral CT (SSCT) and multislice spiral CT (MSCT) in the diagnosis and classification of calcaneal fractures and to present a rapid and precise algorithm for the classification system of Stuermer.


METHODS
In 102 patients with 124 calcaneal fractures, spiral CT was performed, in 82 cases as SSCT with a slice thickness (SD) of 3 mm, a table speed (TS) of 3 - 4 mm/rot and an increment of 1.5 mm. In 42 cases, patients were scanned using MSCT (SD of 1.25 mm, increment 0.8 mm). For these examinations, 2 different scan protocols were used, with a TS of 3.75 mm/rot in one group (n = 21) and a TS of 7.5 mm/rot in the other group (n = 21). The image quality of axial sections and reconstructed images was assessed on a scale from 1 to 5 (1 = very good; 5 = insufficient). The fractures were evaluated using a classification system according to Stuermer, which assigns three main groups (A/B/C) and three subtypes (1/2/3).


RESULTS
MSCT had substantial advantages over SSCT with respect to scan time and image quality, especially for multiplanar reformatting (median 1.5 versus 4.0). TS showed no significant influence on the image quality. The standardized evaluation of the images enabled a classification of fractures within 5 minutes. All fractures could be assigned to the different types and subtypes. This classification system takes into account the severity of the fracture and the therapeutic approach. The most common type (90 of 124 fractures) were "joint depression" fractures (type C), which were treated by surgery in 92 %. Type A fractures were treated conservatively in 72 %.


CONCLUSIONS
Spiral CT, especially MSCT, allows rapid diagnosis and precise classification of calcaneal fractures, achieved with high quality multiplanar reformatting. The presented classification in different fracture types and subtypes allows an adequate planning of therapy.
Herold
T
T
Abteilung Diagnostische Radiologie, Klinikum der Georg-August-Universität Göttingen. thomas.herold@klinik.uni-regensburg.de
Folwaczny
E K
EK
Stürmer
K M
KM
Grabbe
E
E
Funke
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002111:Calcaneus / Q000293:injuries*; D002648:Child; D050723:Fractures, Bone / Q000145:classification / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D013997:Time Factors; D036542:Tomography, Spiral Computed / Q000379:methods*