RESUMO
PURPOSE: To introduce a computational tool for peri-interventional intracranial aneurysm treatment guidance that maps preoperative planning information from simulation onto real-time X-Ray imaging. METHODS: Preoperatively, multiple flow diverter (FD) devices are simulated based on the 3D mesh of the vessel to treat, to choose the optimal size and location. In the peri-operative stage, this 3D information is aligned and mapped to the continuous 2D-X-Ray scan feed from the operating room. The current flow diverter position in the 3D model is estimated by automatically detecting the distal FD marker locations and mapping them to the treated vessel. This allows to visually assess the possible outcome of releasing the device at the current position, and compare it with the one chosen pre-operatively. RESULTS: The full pipeline was validated using retrospectively collected biplane images from four different patients (5 3D-DSA datasets in total). The distal FD marker detector obtained an average F1-score of 0.67 ( ± 0.224 ) in 412 2D-X-Ray scans. After aligning 3D-DSA + 2D-X-Ray datasets, the average difference between simulated and deployed positions was 0.832 mm ( ± 0.521 mm). Finally, we qualitatively show that the proposed approach is able to display the current location of the FD compared to their pre-operatively planned position. CONCLUSIONS: The proposed method allows to support the FD deployment procedure by merging and presenting preoperative simulation information to the interventionists, aiding them to make more accurate and less risky decisions.
RESUMO
We attempted to characterize the 5-hydroxytryptamine (5-HT) receptor type/subtype and mediator mechanisms involved in the contractile effects of 5-HT in the in situ autoperfused kidney of long-term diabetic rats. Diabetes was induced in male Wistar rats by a single subcutaneous injection of alloxan. Intra-arterial (i.a.) bolus injection of 5-HT (0.00000125 to 0.1µg/kg) increased renal perfusion pressure in a dose dependent way but did not affect the systemic blood pressure in long-term diabetic rats. The selective 5-HT2 receptor agonist, α-methyl-5-HT, caused a local vasoconstrictor effect in the in situ autoperfused rat kidney similar to 5-HT. However, BW723C86, a selective 5-HT2B receptor agonist, m-CPP (1-(3-chlorophenyl)piperazine), a selective 5-HT2B/2C receptor agonist, the 5-HT1 receptor agonist, 5-carboxamidotryptamine (5-CT), and the selective 5-HT3 receptor agonist, 1-phenylbiguanide did not modify the renal perfusion pressure. In long-term diabetic rats, vasoconstriction elicited by 5-HT and α-methyl-5-HT was significantly decreased by ritanserin (a 5-HT2 receptor antagonist), spiperone (a 5-HT2A receptor antagonist), and the cyclooxygenase (COX) inhibitors, indomethacin (non-selective COX inhibitor), FR 122047 or nimesulide (selective COX-1 and COX-2 inhibitors, respectively), but was not modified by pretreatment with SB 206553 (3,5-dihydro-5-methyl-N-3-pyridinylbenzo[1,2.b:4,5-b']dipyrrole(1H)-carboxamide hydrochloride), a non-selective 5-HT2C receptor antagonist, prazosin, propranolol, enalapril or losartan. The results of protein expression support these results: COX-1 and COX-2 are expressed in renal tissue. Inducible COX (COX-2) is overexpressed in long-term diabetes. Our data suggest that, in the in-situ autoperfused kidney of long-term diabetic rats, 5-HT vasoconstrictor action is mediated, through cyclooxygenase pathway, by local activation of 5-HT2A receptors.