Möglichkeiten der Frühdiagnostik der Osteomyelitis durch Magnetresonanz-Tomographie - Experimentelle Untersuchungen am Kaninchen

Possibilities of early diagnosis of osteomyelitis by magnetic
resonance tomography - experimental studies in rabbits Correlation
of MR-images and macroscopic sections demonstrates, that anatomical
structures of rabbits can be excellently visualized by MRT.
Clinically used MR-systems are able to provide satisfactory
resolution. Following experimentally induced osteomyelitis infected
bone marrow can be detected by decreased signal on native
T1-weighted and increased signal on T2-weighted images. After
administration of gadolinium-DTPA marked enhancement can be
observed. Detection of soft-tissue infection is superior on
T2-wheigted scans showing high signal intensity. After
administration of gadolinium DTPA rim enhacement provides good
differentiation of abscessmembrane. Especially in earlier stages of
disease (3 to 5, 8 to 12 and 12 to 19 days post infection) the
sensitivity of native MRT (80%, 100%, about 67%) is superior
compared to other diagnostic modalities, e.g. radiography (about
29%, about 46%, 50%), CT-scan (about 29%, about 13%, about 17%) and
scintigraphy (60%, about 78%, 100%). Gadolinium-DTPA increases
sensitivity (100%, 100%, 100%). At the end of the observation
period bone scintigraphy provides the same sensitivity. MRT,
however, is superior in detecting involvement of bone marrow and
soft-tissue infection. Compared to scintigraphy and MRT radiography
and CT-scan shows lower sensitivity during the whole observation
period. Regional differences in detecting osteomyelitis can be
recognized unsing MRT, less using other modalities. In early stages
of the disease most infectious lesions are detected in the proximal
femur. Explanation can be a different involvement of the femur, but
also a different diagnostic potential of MRT concerning different
anatomical regions. All in all MRT is an excellent tool in the
diagnosis of osteomyelitis and is superior to other imaging
modalities. Application of contrast material provides further
improvement in sensitivity. In the clinical use fat suppression and
STIR-sequence have provided further improvement. The role of MRT as
a diagnostic instrument in osteomyelitis is established in clinical
medicine and seems promising in veterinary medicine.