Röntgenmorphometrie und Myelographie der kaninen Lendenwirbelsäule im Hinblick auf die Darstellbarkeit definierter ventrolateraler epiduraler Raumforderungen

Radiographic morphometry and myelography of the canine lumbar spine
with regard to the diagnosis of defined ventrolateral epidural
space occupying lesions. Neurologic disorders with suspicion of
space occupying lesions in the vertebral canal are not always
visible in myelographic standard projections (VD and Si-DeL). For
these indications it might be helpful to include 45°-oblique
myelograms in the radiologic procedure for a precise localisation
of the involved segment or side, as verified by own results and
references. For the investigation 20 euthanized small-breed (group
1), 20 middle-size-breed (group 2) and 21 large-breed dogs (group
3) were needed. The 1069 simulated ventrolateral epidural space
occupying lesions in three different balloonvolume-sizes (l.) were
not visible in 23% (246 of 1069 l.) of the routine VD and Si-DeL
views, but in the 45°-oblique projections. In group 1 22.6% (l.=
119) of the small lesions, in group 2 58% (l.= 118) of the small
and 14.4% (l.= 118) of the middle-size-lesions and in group 3 66.4%
(l.= 119) of the small, 32% (l.= 119) of the middle-size-, and 10%
(l.= 119) of the large lesions became diagnosed only in 45°-oblique
myelograms. In comparison to the 45°-oblique myelograms in which
the lesions were visible in 100% (l.= 1069), they became depicted
in 68% (l.= 1069) in the VD and only in 36% (l. = 1069) in the
Si-DeL view. The possibility to evaluate ventrolateral masses in
45°-oblique views and in no other projections increases
significantly with the weight and body length. The most important
factors are the diameter of the dural sac, the medulla spinalis and
the epidural space.In all three groups of dogs measurements were
made on: the vertebral canal hight and width, spinal cord hight and
width, dural sac hight and width and the epidural space hight and
width. Not expected morphometric differences were seen especially
in group 2. In these, the ratio between the vertebral canal to the
dural sac decreased from L4 to S1 faster than in the other two
groups. This leads to absolutely smaller dural sacs caudal L7. The
dural sacs in group 2 also end earlier in comparison to the other
groups. By the examination of different breeds a significant
variability of the measured diameters was observed. In conclusion
the diameter of the dural sac and epidural space depends not only
on the size of the dog, but also on the breed (eg. Dobermann
pinsher, Foxhound, Staffordshire- and Pitbull-Terrier and
Dachshound).Signifikant correlations between the end of the dural
sac and the crown-rump length, the breed or the age of the dogs
could not be proved.