[Magnetic resonance tomogography after cryotherapy of long bones in an animal model].
OBJECTIVE
To describe the MR findings following cryoablation of long bones.


METHODS
Cryoablation was performed in femoral and tibial bones of 24 sheep under general anesthesia. MRI of the treated and untreated contralateral bones was performed immediately thereafter and at 2, 4 and 6 months after the cryosurgical procedure.


RESULTS
On the MRI performed immediately after cryotherapy, the lesions showed low signal intensities relative to the normal bone marrow on unenhanced T1- and T2-weighted images. At 2, 4 and 6 months after cryoablation, the lesions showed high signal intensities on STIR images, low signal intensities on T1-weighted and heterogeneous enhancement on contrast-enhanced T1-weighted MR images. The femoral lesions decreased in size from 31 +/- 3 mm immediately after the cryotherapy to 13 +/- 4 mm 6 month later and the tibial lesions from 29 +/- 7 mm to 19 +/- 4 mm.


CONCLUSIONS
MRI shows bone marrow lesions immediately after cryotherapy and can easily monitor healing lesions. MR imaging is suitable for following cryotherapy.
Winnekendonk
G
G
Institut und Poliklinik für Radiologische Diagnostik, Klinikum der Universität zu Köln. guido.winnekendonk@t-online.de
Popken
F
F
Smekal
U V
UV
Neumann
L
L
Tietz
A
A
Bosse
M
M
Kasper
H-U
HU
Michael
J
J
Eysel
P
P
Lackner
K
K
D000818:Animals; D017679:Cryotherapy / Q000379:methods*; D004195:Disease Models, Animal; D005266:Femoral Neoplasms / Q000175:diagnosis* / Q000628:therapy*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012756:Sheep; D016896:Treatment Outcome