Pulse sequence optimization for MR imaging using a paramagnetic hepatobiliary contrast agent

Paramagnetic agents enhance contrast between tissues in magnetic resonance (MR) imaging by altering tissue relaxation times. The effect of these changes on MR image intensity depends in part on the choice of operator-controlled pulse sequence parameters. With the newly described paramagnetic hepatobiliary contrast agent, iron(III) ethylenebis-(2-hydroxyphenylglycine), Fe(EHPG)-, an in vivo experimental analysis of pulse sequence optimization was performed on the rat. We compared the enhancement of the liver divided by background noise, EL/N, of standard inversion-recovery (IR) and spin-echo (SE) T1-weighted pulse sequences and several pulse sequences theoretically predicted to have improved EL/N. Optimization of the echo time (TE = TEmin) gave a substantial (greater than 60%) increase in EL/N over the standard IR and SE pulse sequences. Images obtained with optimized repetition rate and inversion time gave only a slight additional improvement. Within the uncertainties of our relaxation measurements, the measured changes in EL/N with pulse sequence optimization corresponded well with theoretical predictions. With the experimental and theoretical data, the importance of using a short echo time to obtain maximal T1 contrast in contrast-enhanced MR imaging and the relative merits of optimized SE versus IR pulse sequences for contrast-enhanced MR imaging are discussed.     

Cyclic Neutropenia in Grey Collie Dogs

Cyclic neutropenia in a grey collie dog was first diagnosed at 10 weeksof age and has persisted 12 months. The average cycle length was 10.6 dayswith a range of 8 to 12 days. The condition was found in 2 other dogs of thetype described and appears to be inherited along with a grey (silver) coat.The peripheral neutropenia results from a cyclic maturation arrest in the bonemarrow at the level of differentiation from the stem cell.

Submitted on July 21, 1966 Accepted on September 21, 1966     

Intake of Drugs among Elderly People in a Danish Municipality,Rødovre

ABSTRACT. Drug intake has been studied among a random group of persons, aged 75 or over, in Rødovre Municipality. Two hundred and eighty-three elderly persons living in their own homes have been visited and interviewed about their daily intake of prescribed and non-prescribed drugs (including so-called natural drugs). Similar information was gathered from 146 elderly persons living in nursing homes. Thirty-one per cent of the elderly living in their own homes and 3% of those living in nursing homes did not use prescribed drugs daily. The median daily amount of different types of drugs used was 1.8 (range 0–10) for elderly persons living in their own homes and 4.5 (range 0–11) (p<0.001) for those living in nursing homes. Women living at home had a higher intake of drugs than men, especially diuretics. The most frequently used drugs were diuretics, sedatives/hypnotics, analgesics, digitalis and electrolytes. For all types of drugs a higher consumption, especially of phenothiazines, was found among elderly persons living in nursing homes. Drug consumption was independent of age and social stratification in both groups. The use of non-prescribed drugs ranges from 0 to 9 different types in the group living in their own homes, and from 0 to 5 in the group living in nursing homes—laxatives being the type most frequently used.