[Morphology of low-velocity impact stains produced from single drops of blood]. / Zur Morphologie langsam beschleunigter Blutauftropfspuren.

Systematic variation of blood droplet volume, the distance fallen and the surface (paper, wood, plastics, tiles) led to the conclusion that the size and the shape of the stains ("fingers", satellites) allowed to deduce the distance fallen but only if the actual surface structure was known. We found that detailed photography at the crime scene was necessary, yet experiments have to be performed due to the extreme influence of the actual surface texture on all characteristics (size, spines, peripheral spatter) of the blood stains.

[Proton spinlocking and T1 rho-weighted MR imaging at 1.5 T]. / Protonen-Spinlock und T1 rho-gewichtete MR-Bildgebung bei 1,5 T.

During spinlocking, the magnetization is aligned along an oscillating field (RF) and relaxes with time constant T1 rho, the spin-lattice relaxation time in the rotating frame. Using a clinical whole-body MR scanner, methods of spinlocking preparation and signal acquisition were combined to evaluate the potential of T1 rho-weighted MR imaging (T1 rho w-MRI) at B0 = 1.5 T. Examinations of the brain of healthy volunteers yielded images with pronounced contrast and T1 rho-variation of the tissue. However, the contrast resembled that of T2-weighted MRI, which is explained by the restricted spinlocking-field strength (BSL < or = 6 microT) on the tomograph. The result (mono-exponential fit) of serial T1 rho w-MRI data from examinations of 8 volunteers was on average 105 +/- 4 ms in the gray matter and 86 +/- 4 ms in the white matter (for BSL = 3 microT). The values are comparable to T2 of both tissues. MRT with spinlocking is less susceptible to local magnetic field inhomogeneities than conventional MRI.