Cobalt-55 positron emission tomography in ischemic stroke.

After acute cerebral stroke, the (peri-) infarct tissue is characterized by calcium (Ca)-mediated neuronal damage and inflammatory processes. Monitoring Ca-mediated damage using the isotope cobalt-55 (Co) as a Ca-tracer may enable PET-imaging of this tissue. Since the fate of (peri-) infarct tissue determines clinical outcome, Co-PET may have prognostic value in stroke. Six stroke patients were examined with Co-PET, MRI and a middle cerebral artery (mca) stroke scale (Orgogozo). In every patient, specific Co-accumulation in the appropriate brain region was seen, irrespective of the integrity of the blood-brain barrier. This pilot study suggests Co-PET as a diagnostic tool in stroke, which may provide additional information on the clinical outcome. Validation of method in larger patient series is necessary.

Visualization of damaged brain tissue after ischemic stroke with cobalt-55 positron emission tomography.

UNLABELLED: In animal experiments, the radionuclide 55Co2+ has been shown to accumulate in degenerating cerebral tissue similar to Ca2+. METHODS: The potential role of 55Co2+ for in vivo brain PET imaging was investigated in four patients after ischemic stroke. RESULTS: PET showed uptake of 55Co2+ in damaged brain tissue irrespective of blood-brain barrier integrity, as affirmed by CT and MRI. CONCLUSION: Our preliminary results indicate that 55CoCl2 may prove to be a useful and relatively inexpensive PET radiopharmaceutical for visualization of degenerative processes in brain tissue.

CT in neuromuscular disorders: a comparison of CT and histology.

The value of CT-examination of the muscles compared to histology was studied in a retrospective analysis of 30 patients with clinical suspicion of neuromuscular disorder. In the evaluation of the CT-results descriptive criteria were used. The histologic diagnosis came from needle-biopsies taken from the quadriceps muscle. Considering the whole group of neuromuscular disorders, CT has an overall accuracy of 84.8%, a positive predictive value of 95.5% and a negative predictive value of 63.6%. This makes the use of CT as a diagnostic tool in neuromuscular disorders a reliable examination technique. In patients with a polymyositis there is even a 100% correlation between CT findings and biopsy results. Discrepancy between the biopsy results of the quadriceps muscle and the CT findings is remarkable: the number of abnormal histological findings is twice the number of abnormal CT findings. Using the more proximal gluteal region as a biopsy site would have decreased this discrepancy and would therefore have given a better correlation between CT and histology. The choice of protocol in determining the levels to be scanned is of great importance in achieving good reproducability in follow-up CT examinations.

Bilateral direct carotid-cavernous fistulas of traumatic and spontaneous origin: two case reports.

In the present paper we discuss two cases with bilaterally located carotid-cavernous fistulas: one of traumatic origin and the other occurring spontaneously. Most traumatic fistulas are direct, unilateral and of a high flow type. In our first case we deal with traumatic bilateral direct fistulas with a low flow, a combination which must be considered rare and is not reported in the literature so far. In our second case there are bilaterally located fistulas, occurring spontaneously. Peculiarly they are direct, instead of indirect as is to be expected in spontaneously developing fistulas, and of a low flow type. This combination too must be considered extremely rare. In both cases conservative therapy was successful, despite their difference in etiology. It appears that neither the anatomy nor the manner of onset determines the success of conservative therapy, but the fact that a fistula is of a high- or low flow type.