[Torsional defects of the lower limb: an evaluation of the reliability of the results obtained by CT].
The torsional angle was calculated goniometrically of 9 femurs and 2 tibio-peroneal groups, and then compared to the values obtained from CT scans of the corresponding bones. The results show how the methods adopted up to now have been inaccurate and have yielded only gross definitions of the axis of the femoral neck. As far as this feature is concerned, an error of +/- 6.5 degrees can be estimated, with limits of confidence of 95%, after applying a more accurate system of measurement to the images and considering statistical interferences. After pointing out the advantages of this method, we suggest that the test performed in vivo be systematically proposed to all those patients in whom a more accurate diagnosis would lead to a different medical/surgical therapy considering that: 1) the inevitable error such a measurement bears can be contained between acceptable limits; 2) the radiation dose sufficient to distinguish the bone from the other surrounding tissues is much reduced with respect to the dosage necessary to perform a common CT of the inferior limbs. It comprises one topogram and four tomograms, with a total dose to the patient of approximately 10-20 mGy.
Allegri
F
F
Istituto di Radiologia, Università, Padova.
Carugno
C
C
Ravasini
R
R
Bordin
M
M
Turra
S
S
Gigante
C
C
D002102:Cadaver; D003951:Diagnostic Errors; D005269:Femur / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005360:Fibula / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D007866:Leg / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D013977:Tibia / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000592:standards*; D014102:Torsion Abnormality
Difetti torsionali dell'arto inferiore: valutazione dell'attendibilità dei risultati ottenibili con TC.