[Clinical relevance of a routinely performed magnetic resonance cholangiopancreatography (MRCP) prior to cholecystectomy]. / Klinische Wertigkeit einer routinemäßigen Magnetresonanz-Cholangiopankreatikografie (MRCP) vor Cholezystektomie.

BACKGROUND: A preoperative diagnostic imaging procedure is essential for therapy in cholecystolithiasis. According to the S3-Guidelines of the German Society for General and Visceral Surgery only an ultrasound scan is needed before a cholecystectomy. But an anatomic variant of the bile ducts or choledocholithiasis is poorly shown by an ultrasound. Because of this, we performed a magnetic resonance cholangiopancreatography (MRCP) routinely. This study was designed to show if the MRCP changed the treatment plan or changed the operation method. Furthermore, the sensitivity and specificity concerning abnormalities of the cystic duct, accessory bile ducts and choledocholithiasis should be determined. PATIENTS AND METHODS: During the time between January 1st 2005 and September 30th 2009 541 patients were included in this retrospective study. RESULTS: Among the 541 cases 98 pathologies were found. These included 51 choledocholithiasis, 20 accessory bile ducts and 13 abnormal cystic ducts. In 29 of the 51 cases of choledocholithiasis a therapeutic splitting was performed only because of the MRCP. In 22 cases the diagnosis was also possible because of the basic diagnostic procedures like ultrasound, laboratory tests and clinical appearance. So the diagnostic aimprovement due to the MRCP is 5.3 %. Four of the 20 accessory bile ducts and 6 of the abnormal cystic ducts were found during the subsequent operation. The sensitivity concerning the anatomic variants is very low (38.5 % concerning the accessory bile ducts and 50 % for the abnormal cystic ducts). But the sensitivity in detecting a choledocholithiasis is very high (94.7 %). There was no evidence in our study that MRCP prevented any complications. The operation method was not changed in any case because of the MRCP result. CONCLUSION: A routinely performed preoperative MRCP cannot be recommended.

Nuclear magnetic spin-lattice relaxation of water protons caused by metal cage compounds.

The nuclear magnetic spin-lattice relaxation rates of water protons are reported for solutions of manganese(II), copper(II), and chromium(III) cage complexes of the sarcophagine type. As simple aqueous solutions, the complexes are only modest magnetic relaxation agents, presumably because they lack protons on atoms in the first-coordination-sphere protons that are sufficiently labile to mix the large relaxation rate at the metal complex with that of the bulk solvent. The relaxation is approximately modeled using spectral density functions derived for translational diffusion of the interacting dipole moments with the modification that the electron spin relaxation rate is directly included as a contribution to the correlation time. In all cases studied, the electron spin relaxation rate is sufficiently large that it contributes directly to the water-proton spin relaxation process. The poor relaxation efficiency of the cage compound may, however, be improved dramatically by binding the complex to a protein. The efficiency is improved even further if the rotational motion of the protein is reduced drastically by an intermolecular cross-linking reaction. The relaxation efficiency of the cross-linked protein-cage complexes rivals that of the best first-coordination-sphere relaxation agents like [Gd(DTPA)(H2O)]2- and [Gd(DOTA)(H2O)]-.