In an animal model nephrogenic systemic fibrosis cannot be induced by intraperitoneal injection of high-dose gadolinium based contrast agents.

AIM AND OBJECTIVE: Nephrogenic systemic fibrosis (NSF) has been reported in humans to be most likely induced by gadolinium based contrast agents (GBCA), namely by gadodiamide, gadopentetate dimeglumine, and gadoversetamide, rarely by other GBCA. The pathogenesis of NSF remains unclear; different hypotheses are under discussion. The objective of the study is to assess if in the animal model human-like NSF changes can be induced by high-dose, intraperitoneal GBCA injections over four weeks. MATERIALS AND METHODS: After approval by the institutional animal ethics committee, six rats each were randomly assigned to groups, and treated with seven different GBCA. Intraperitoneal (IP) injections - proven in the animal model to be effective - were chosen to prolong the animals' exposure to the respective GBCA. GBCA doses of previous intravenous (IV) animal studies were applied. After five weeks all rats were sacrificed. Sham controls were treated with IP saline injections, employing the same regimen. RESULTS: No findings comparable with human NSF were observed in all animals after IP treatment with all seven GBCA at daily doses of 2.5 and 5.0 mmol/kg body weight (BW). No histopathological abnormalities of all examined organs were noted. Weight loss was stated in weeks three and four with GBCA injections at doses of 5.0 mmol/kg BW, but rats regained weight after cessation of GBCA treatment. CONCLUSIONS: NSF-comparable pathological findings could not be induced by high dose intraperitoneal injection of seven GBCA.

Comparison of two imaging protocols for acute stroke: unenhanced cranial CT versus a multimodality cranial CT protocol with perfusion imaging.

The aim of the study was to validate a multimodality cranial computed tomography (CCT) protocol for patients with acute stroke in the United Arab Emirates as a basic imaging procedure for a stroke unit. Therefore, a comparative study was conducted between two groups: retrospective, historical group 1 with early unenhanced CCT and prospective group 2 undergoing a multimodality CCT protocol. Follow-up unenhanced CCT>48 h served as gold standard in both groups. Group 1: Early unenhanced CCT of 50 patients were evaluated retrospectively, using Alberta Stroke Program Early CT Score, and compared with the definite infarction on follow-up CCT. Group 2: 50 patients underwent multimodality CCT (unenhanced CCT, perfusion studies: cerebral blood flow, cerebral blood volume, mean transit time and CT angiography)<8 h after clinical onset and follow-up studies. Modified National Institute of Health Stroke Scale was used clinically in both groups. Group 1 showed 38 men, 12 women, clinical onset 2-8 h before CCT and modified National Institute of Health Stroke Scale 0-28. Group 2 included 38 men, 12 women, onset 3-8 h before CCT, modified National Institute of Health Stroke Scale 0-28. Sensitivity was 58.3% in group 1 and 84.2% in group 2. Computed tomography angiography detected nine intracranial occlusions/stenoses. The higher sensitivity of the multimodality CCT protocol justifies its use as a basic diagnostic tool for the set-up of a first-stroke unit in the United Arab Emirates.